Novel antibody-drug conjugates with novel NaPi2b antibodies, therapeutic methods, and uses thereof

Abstract

The present invention relates to novel anti-NaPi2b antibodies, novel antibody-drug conjugates (ADCs) based thereon, and therapeutic methods and uses thereof, particularly for the treatment of cancer.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 22202154, filed with the European Patent Office on October 18, 2022, the contents of which are incorporated herein in their entirety for all purposes.

[0002] This application claims priority to European Patent Application No. 23172910, filed with the European Patent Office on May 11, 2023, the contents of which are incorporated herein in their entirety for all purposes.

[0003] Sequence Listing This application contains a Sequence Listing in computer readable form, which is incorporated herein by reference.

[0004] Technical field of the invention The present invention relates to novel anti-NaPi2b antibodies, novel antibody-drug conjugates (ADCs) based thereon, and therapeutic methods and uses thereof, particularly for the treatment of cancer. [Background technology]

[0005] Background of the Invention NaPi2b, a multitransmembrane sodium-dependent phosphate transporter encoded by the SLC34A2 gene, is expressed in human lung, ovarian, and thyroid cancers, as well as in the normal tissues from which these tumors originate. As a member of the SLC34 solute transporter protein family, it is responsible for transcellular inorganic phosphate uptake and maintenance of phosphate homeostasis, and is associated with cell differentiation and tumorigenesis. Napi2b mRNA / protein expression has been observed in non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, and papillary thyroid cancer; normal tissue expression has been reported in the lung, bronchi, and kidney (Lin et al., 2015). In normal lung tissue, NaPi2b is involved in phosphate transport, and mutations in SLC34A2 have been associated with pulmonary and testicular microlithiasis (Corut et al., 2006). Napi2b is a promising target for ADC therapy due to its differential expression in tumors compared with most normal tissues, its prominent cell surface localization, and its high endocytosis rate. Although several first-generation antibody-drug conjugates have been developed in the past, they either do not provide long-term survival benefits or are associated with dose-limiting toxicities.

[0006] Therefore, there is a need for novel antibodies with improved characteristics and ADCs based thereon that have improved toxicity profiles and higher functionality.The technical problem of the present invention is therefore to meet this need.

[0007] The present invention fulfills this need by providing, inter alia, novel anti-NaPi2b antibodies that have a reduced tendency for antibody modification by post-translational or post-expression and post-purification modifications (e.g., deamidation), improved on-target binding, improved target-dependent internalization rates, limited tendency for aggregation and HMWS formation, and cross-reactivity with rat Napi2b and cynomolgus monkey NaPi2b, which have similar binding capabilities to human Napi2b (allowing for better toxicity analysis and cross-comparison); and novel NaPi2b-targeting antibody-drug conjugates (ADCs) based thereon, generated by applying P5 conjugation technology (e.g., WO2018 / 041985) (based on modification of interchain cysteine ​​residues with unsaturated phosphonamidate reagents); and therapeutic methods and uses thereof, particularly for cancer treatment. Summary of the Invention

[0008] This technical problem is solved by the subject matter defined in the claims.

[0009] Accordingly, the present invention relates to an antibody-drug conjugate (ADC) comprising an anti-NaPi2b antibody (e.g., an antibody against NPT2B_human sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: O95436 or SEQ ID NO: 1) and / or an antibody against NPT2B_rat sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2)), wherein (a) the NaPi2b antibody is capable of binding to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), and preferably, the binding to the human Napi2b and the rat Napi2b has approximately the same K D and more preferably, the antibody is selected from the group consisting of AV-25 antibody, AV-15 antibody, AV-18 antibody, AV-21 antibody, and AV-29 antibody, and most preferably, the antibody has approximately the same K D(b) the NaPi2b antibody is capable of cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2); (c) the NaPi2b antibody is capable of cross-reactivity with cynomolgus monkey (e.g., Macaca fascicularis) Napi2b (e.g., having UniProtKB Accession No.: A0A2K5UHY1 or SEQ ID NO: (d) the NaPi2b antibody is capable of internalization, preferably by antigen-mediated antibody internalization; (e) the NaPi2b antibody optionally comprises a heavy chain variable region (V H ) may have no dipeptide deamidation site within CDR2, and preferably, the absent dipeptide deamidation site is V H and NG (Asn-Gly) in CDR2; the NaPi2b antibody may have one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably Preferably 8) cytotoxic moieties (e.g., a cytotoxic payload, e.g., a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethyl auristatin E) or MMAF (monomethyl auristatin F), e.g., exatecan), preferably via one or more linkers, more preferably via one or more phosphonamidate linkers.

[0010] The present invention further relates to antibody drug conjugates (ADCs) of the invention comprising an anti-NaPi2b antibody of the invention (e.g., a humanized monoclonal NaPi2b-specific IgG1 antibody) conjugated to a cytotoxic payload / drug, wherein (a) the cytotoxic payload is selected from the group consisting of camptothecin, maytansinoid, calicheamicin, duocarmycin, tubulysin, amatoxin, dolastatin, and auristatin, such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof; and / or (b) the cytotoxic payload is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker (L) comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, wherein the releasing unit is cleavable by a protease.Preferably, the drug (e.g., cytotoxic moiety (e.g., a cytotoxic payload, e.g., a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan) to antibody ratio (DAR) is in the range of 0 to 20, more preferably the DAR is in the range of 4 to 8, and most preferably the DAR is 4 or 8.

[0011] The present invention further relates to compositions or kits comprising the antibody drug conjugates (ADCs) of the invention.

[0012] The present invention further relates to methods for synthesizing the antibody drug conjugates (ADCs) of the invention.

[0013] The present invention further relates to methods of treatment and uses of the antibody drug conjugates (ADCs), compositions, and / or kits of the invention.

[0014] Sequence Listing Overview As described herein, unless otherwise specified, UniProtKB accession numbers ( https: / / www.uniprot.org / release-notes / 2022-08-03-release , available in UniProt release 2022_03, published on August 3, 2022).

[0015] This application contains a Sequence Listing in computer readable form, which is incorporated herein by reference. [Brief explanation of the drawings]

[0016] The present invention will be better understood by reference to the detailed description, when considered in conjunction with the non-limiting examples and the accompanying drawings, in which: [Figure 1-1] 1 shows exemplary sequences of anti-NaPi2b antibodies of the invention. [Figure 1-2] This is a continuation of Figure 1-1. [Figure 1-3]This is a continuation of Figure 1-2. [Figure 2] 1 shows a charge variant analysis for an exemplary antibody of the invention. [Figure 3] Binding to human and rat NaPi2B as assessed by flow cytometry is shown. Graphs show mean values ​​(n=2)±SEM. [Figure 4] Binding to immobilized human NaPi2B as assessed by ELISA is shown. Graph shows mean values ​​(n=2)±SEM. [Figure 5] Internalization assessed by flow cytometry is shown. [Figure 6] Melting curves evaluated by NanoDSF are shown. [Figure 7] Figure 1 shows in vitro cytotoxicity assessed by resazurin assay in NaPi2B-positive cells. Graph shows mean (n=2) ± SEM. [Figure 8] The bystander activity of ADC is shown. [Figure 9] 1 shows in vitro inhibition of topoisomerase I by ADC-mediated delivery of exatecan. [Figure 10] 1 shows in vivo PK evaluation for the ADC and unconjugated antibody. [Figure 11] 1 shows a UV chromatogram of P5(PEG12)-COOH measured by LC / MS. [Figure 12] 1 shows a UV chromatogram of P5(PEG24)-OSu measured by LC / MS. [Figure 13] 1 shows a UV chromatogram of NH2-VC-PAB-exatecan TFA salt measured by LC / MS. [Figure 14] 1 shows a UV chromatogram of NH2-VA-PAB-exatecan TFA salt measured by LC / MS. [Figure 15] 1 shows a UV chromatogram of P5(PEG2)-VC-PAB-exatecan measured by LC / MS. [Figure 16]1 shows a UV chromatogram of P5(PEG12)-VC-PAB-exatecan measured by LC / MS. [Figure 17] 1 shows a UV chromatogram of P5(PEG24)-VC-PAB-exatecan measured by LC / MS. [Figure 18] 1 shows a UV chromatogram of P5(PEG12)-VA-PAB-exatecan measured by LC / MS. [Figure 19] 1 shows a UV chromatogram of P5(PEG12)-exatecan measured by LC / MS. [Figure 20] 1 shows analytical characterization of the synthesized mAb and DAR8-ADC derived from P5(PEG24)-VC-PAB-exatecan. [Figure 21] Analytical raw data for AV25 are shown. (A-D) Analytical characterization of one of the described mAbs. The antibody was expressed in Expi-CHO cells and purified by Protein A chromatography as previously described. The mAb was analyzed by HLPC-SEC (A), LC-MS (B), HLPC-HIC (C), and reducing SDS-PAGE (D). [Figure 22] LC / MS analysis of the parent antibody is shown. [Figure 23] LC / MS analysis of AV15 is shown. [Figure 24] LC / MS analysis of AV18 is shown. [Figure 25] LC / MS analysis of an exemplary antibody, AV21, is shown. [Figure 26] LC / MS analysis of an exemplary antibody, AV25, is shown. [Figure 27] LC / MS analysis of an exemplary antibody, AV29, is shown. [Figure 28]Analytical raw data for AV25-P5(PEG24)-VC-PAB-exatecan DAR 8 are shown. (A-D) Analytical characterization of one of the ADCs synthesized and purified as previously described. A) Analytical size exclusion chromatography, B) LC-MS of the ADC preparation, C) Analytical hydrophobic interaction chromatography after conjugation. The data show that the ADC is fully conjugated to a DAR of 8, with only small amounts of aggregates present after purification. [Figure 29] LC / MS analysis of parent P5(PEG24)-VC-PAB-exatecan DAR8. [Figure 30] FIG. 1 shows an LC / MS analysis of an exemplary ADC of the invention, AV15-P5(PEG24)-VC-PAB-exatecan (DAR8). [Figure 31] FIG. 1 shows an LC / MS analysis of an exemplary ADC of the invention, AV18-P5(PEG24)-VC-PAB-exatecan (DAR8). [Figure 32] FIG. 1 shows an LC / MS analysis of an exemplary ADC of the invention, AV21-P5(PEG24)-VC-PAB-exatecan (DAR8). [Figure 33] FIG. 1 shows an LC / MS analysis of an exemplary ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR8). [Figure 34] 1 shows an LC / MS analysis of an exemplary ADC of the invention, AV29-P5(PEG24)-VC-PAB-exatecan (DAR8). [Figure 35] 1 shows the results of an ex vivo serum stability analysis of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), a representative ADC of the invention. [Figure 36] 1 shows the results of an in vivo efficacy analysis of a representative ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), in a cell line-derived xenograft model (CDX). [Figure 37-1]1 shows the results of an in vivo efficacy analysis of a representative ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), in a patient-derived xenograft model (PDX). [Figure 37-2] See description of Figure 37-1. [Figure 37-3] See description of Figure 37-1. [Figure 37-4] See description of Figure 37-1. [Figure 38] 1 shows the results of an in vivo toxicity analysis of a representative ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), in cynomolgus monkeys. [Figure 39] MS analysis of an anti-Napi2b comparative ADC synthesized by the method described above is shown. Signals are annotated with their measured mass (units: Daltons) and absolute intensity. An example spectrum from the conjugation reaction is shown. The drug-to-antibody ratio of the final conjugate was estimated to be 3.5-4.0 from the MS signal. LC: light chain of the anti-Napi2b comparative antibody; HC: heavy chain of the anti-Napi2b comparative antibody. [Figure 40] Binding of unmodified AV25 mAb and AV25-P5(PEG24)-VC-PAB-exatecan DAR8 ADC to HEK293 cells transfected with Napi2a (left), Napi2b (center), and Napi2c (right) is shown, expressed as MFI ratio. AV25 mAb and AV25-P5(PEG24)-VC-PAB-exatecan DAR8 ADC specifically bind to NaPi2b. Graphs show n=2±SD (note that error bars are too small to display). [Figure 41] Figure 1 shows the cytotoxic dose response of AV25-P5(PEG24)-VC-PAB-exatecan DAR 8 compared to anti-Napi2b comparator ADCs in three different cell lines. Mean and SD of two measurements and dose-response fitting are shown. Fluorescence (units: %) compared to medium control equals the percentage of viable cells. [Figure 42]Dose-dependent induction of DNA damage and signs of apoptosis in response to treatment with increasing concentrations of AV25-P5(PEG24)-VC-PAB-exatecan DAR8 is shown. The corresponding non-targeting isotype control conjugate was included as a negative control. HCC-78 cells (A, NaPi2b high) and OVCAR-3 cells (B, NaPi2b high) were treated with increasing concentrations (0.05–12 μg / ml) of AV25-P5(PEG24)-VC-PAB-exatecan DAR8 or the isotype ADC (isotype-P5(PEG24)-VC-PAB-exatecan DAR8) for 72 hours. Cells were stained for cleaved PARP (left), caspase 3 (center), and pH2AX (right) and analyzed by flow cytometry. Graphs show mean values ​​(n=2) ± SEM. [Figure 43] This figure shows the binding of the Fc region of the AV25 HC-LALA and AV25 HC-wt antibodies to recombinant hexameric C1q complement protein, as measured in a homogeneous time-resolved fluorescence (HTRF)-based human C1q binding assay (HTRF Human C1q Binding Kit, Cisbio) according to the manufacturer's instructions. Briefly, serial dilutions from 280 nM to 11.6 nM were measured for all antibodies tested (AV25 HC-wt, AV25 HC-LALA, α-MHC-I positive, IgG1 kit standard). HTRF ratios were calculated by dividing the acceptor emission signal at 665 nm by the donor emission signal at 620 nm and multiplying by 10,000. The graph shows the HTRF ratio at a concentration of 70 nM, after subtracting the background HTRF ratio (diluent only). The graph shows the mean (n = 2) ± SD. [Figure 44]Figure 1 shows the dose-dependent binding of the AV25-HC-LALA antibody and AV25-P5(PEG24)-VC-PAB-exatecan DAR8 ADC and the Fc region of the AV25-HC-wt antibody to recombinant human FcRn and FcγR. This was measured using the Lumit™ FcγR binding immunoassay (FcγRn, FcγRI, FcγRIIa / CD32 R131 / H131 polymorphism, FcγRIIIa / CD16 V158 / F158 polymorphism, Promega) according to the manufacturer's instructions. Serial dilutions of AV25 HC-wt, AV25 HC-LALA, and AV25-P5(PEG24)-VC-PAB-exatecan DAR8, standards, and trastuzumab as a positive control were incubated with Tracer-LgBiT and FcγR-SmBiT. In the absence of antibody analyte or in the absence of interaction between the antibody being tested and FcγR, Tracer-LgBiT binds to the FcγR-SmBiT target, resulting in a maximum luminescence signal. Upon successful interaction with FcγR, the antibody / ADC being tested competes with Tracer-LgBiT for binding to the FcγR target, resulting in a concentration-dependent decrease in luminescence signal. Luminescence was measured using a microplate reader, Infinite M200 Pro (Tecan). Graphs show n=1. [Figure 45] Antibody-dependent cellular cytotoxicity (ADCC) assay based on calcein release is shown. Cocultures of NK cells from healthy donors (HDs) with calcein-stained target-positive tumor cells (OVCAR-3 and HCC-78) at a 4:1 ratio were incubated with 15 μg / ml of the indicated antibody or ADC (anti-MHC-I antibody served as a positive control). % specific killing was calculated by dividing the calcein released by antibody-mediated cell killing by the calcein released by Triton X-permeabilized cells (maximal killing). Graphs show mean values ​​(n=2) ± SEM. [Figure 46]

[0033] Figure 1 shows the results of an in vivo efficacy analysis of a representative ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), in a patient-derived non-small cell lung cancer (NSCLC) xenograft model (PDX, Lu7700). Shown on the left is the time course of tumor volume following a single treatment on day 0 with various dose levels of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) (1 mg ADC / kg body weight, 3 mg ADC / kg body weight, and 5 mg ADC / kg body weight) and an isotype control (5 mg / kg) with the same amount of linker payload, compared to untreated (vehicle). Shown on the right is the body weight of animals treated with various dose levels of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) and an isotype control with the same amount of linker payload, compared to untreated (vehicle). All results are presented as the mean and SEM of four animals per group. [Figure 47]Figure 47A shows the results of an in vivo efficacy analysis of a representative ADC of the invention, AV25-P5(PEG24)-VC-PAB-exatecan DAR 8, in a patient-derived ovarian cancer xenograft model (PDX, Ov6668). Shown on the left is the time course of tumor volume following a single treatment on day 0 with various dose levels of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) (1 mg ADC / kg body weight, 3 mg ADC / kg body weight, and 5 mg ADC / kg body weight) compared to untreated (vehicle). Shown on the right is the body weight of animals treated with various dose levels of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) compared to untreated (vehicle). All results are presented as the mean and SEM of 9 animals per group. Figure 47B shows in vivo PK evaluation of total and intact ADC at three dose levels of a dose-response efficacy study, shown as the mean and SD of three measurements per time point from mice treated once on day 0 with various dose levels of AV25-P5(PEG24)-VC-PAB-exatecan (1 mg ADC / kg body weight, 3 mg ADC / kg body weight, and 5 mg ADC / kg body weight). PK evaluation was performed as described in Example 1. [Figure 48]

[0023] Figure 1 shows the results of an in vivo efficacy analysis of a representative ADC of the present invention, AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8), in a patient-derived ovarian cancer xenograft model. Shown at the top is the time course of tumor volume following a single treatment on day 0 with 10 mg ADC / kg body weight of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) or isotype-P5(PEG24)-VC-PAB-exatecan (DAR 8), compared to untreated (vehicle). Shown at the bottom are a NaPi2B-low-expressing BRCA-mutated model (lower left) and a NaPi2B-high-expressing BRCA-mutated model (lower right). All results are presented as the mean and SEM of three animals per group. [Figure 49]Dose-dependent binding of increasing concentrations of upifitamab or AV25 in two different NaPi2b-positive cell lines (left: OVCAR-3, right: HCC78) is shown, normalized to the nonspecific binding control and expressed as MFI ratios. The mean and SD of two measurements, as well as the dose-response fitting, are shown. [Figure 50] The cytotoxic dose response of AV25-P5(PEG24)-VC-PAB-exatecan DAR 8 is shown in two different cell lines compared to upifitamab-P5(PEG24)-VC-PAB-exatecan DAR 8 and the isotype control, isotype-P5(PEG24)-VC-PAB-exatecan DAR 8. The mean and SD of two measurements are shown, as well as the dose-response fitting. Fluorescence (unit: %) compared to the medium control equals the percentage of viable cells. DETAILED DESCRIPTION OF THE INVENTION

[0017] Detailed Description of the Invention The invention is described in detail below and is also illustrated by the accompanying examples and drawings.

[0018] The present inventors have produced and characterized a novel specific anti-NaPi2b antibody for specifically targeting the extracellular domain of NaPi2b, which is particularly advantageous for a new therapeutic method for treating cancer (e.g., preferably, the cancer is a solid cancer and / or a metastatic cancer, more preferably, the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, and fallopian tube cancer).

[0019] The present invention provides novel anti-NaPi2b antibodies that have a reduced tendency for antibody modification by post-translational modifications (e.g., deamidation), improved on-target binding, improved target-dependent internalization rates, limited tendency for aggregation and HMWS formation, and cross-reactivity with rat Napi2b and cynomolgus monkey NaPi2b, which have binding capabilities similar to human Napi2b (allowing for better toxicity analysis and cross-comparison); and novel NaPi2b-targeting antibody-drug conjugates (ADCs) based thereon, generated by applying P5 conjugation technology (e.g., WO2018 / 041985) (based on modification of interchain cysteine ​​residues with unsaturated phosphonamidate reagents); and therapeutic methods and uses thereof, particularly for cancer treatment.

[0020] The novel antibodies of the present invention optionally contain Fc silencing mutations, such as leucine (L) to alanine (A) substitutions at positions 234 and 235 (LALA mutations), bind to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), have cross-reactivity with rat Napi2b and cynomolgus monkey Napi2b, and optionally contain a heavy chain variable region (V H ) does not have a dipeptide deamidation site in CDR2, and preferably, the non-existent dipeptide deamidation site is V H NG (Asn-Gly) in CDR2, a humanized anti-NaPi2b monoclonal antibody (mAb).

[0021] The antibody drug conjugates (ADCs) of the present invention comprise an anti-NaPi2b antibody of the present invention (an antibody against NPT2B_human sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: O95436 or SEQ ID NO: 1) and / or an antibody against NPT2B_rat sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2)), wherein (a) the NaPi2b antibody is capable of binding to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), and preferably, the binding to the human Napi2b and the rat Napi2b has approximately the same K D and more preferably, the antibody is selected from the group consisting of AV-25 antibody, AV-15 antibody, AV-18 antibody, AV-21 antibody, and AV-29 antibody, and most preferably, the antibody has approximately the same K D (b) the NaPi2b antibody is capable of cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2); (c) the NaPi2b antibody is capable of cross-reactivity with cynomolgus monkey (e.g., Macaca fascicularis) Napi2b (e.g., having UniProtKB Accession No.: A0A2K5UHY1 or SEQ ID NO: 3); (d) the NaPi2b antibody is capable of internalization, preferably by antigen-mediated antibody internalization; (e) the NaPi2b antibody optionally comprises a heavy chain variable region (V H ) may have no dipeptide deamidation site within CDR2, and preferably, the absent dipeptide deamidation site is V Hand NG (Asn-Gly) in CDR2; wherein the anti-NaPi2b antibody is a cytotoxic payload, e.g., a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan (e.g., CAS No.: 171335-80-1), preferably via one or more linkers, more preferably via one or more phosphonamidate linkers.

[0022] definition antibody "Antibody," as used herein, can refer to a protein comprising one or more polypeptides (comprising one or more binding domains and / or antigen-binding portions, preferably antigen-binding domains) substantially or partially encoded by immunoglobulin genes or fragments of immunoglobulin genes. The term "immunoglobulin" (Ig) is used synonymously with "antibody" herein. Recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon, and mu constant region genes, as well as myriad immunoglobulin variable region genes. In particular, an "antibody," as used herein, is typically a tetrameric glycosylated protein composed of two light (L) chains of approximately 25 kDa each and two heavy (H) chains of approximately 50 kDa each. Two types of light chains, called lambda and kappa, can be found in antibodies. Depending on the amino acid sequence of the heavy chain constant domain, immunoglobulins can be assigned to five major classes: A, D, E, G, and M. Some of these can be further divided into subclasses (isotypes), such as IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. IgG is preferred for the present invention. Antibodies of the present invention having an IgE constant domain or a portion thereof that is bound by Fc epsilon receptor I are also contemplated. IgM antibodies consist of five basic heterotetrameric units and an additional polypeptide called the J chain, containing 10 antigen-binding sites, whereas IgA antibodies contain two to five basic four-chain units, which can polymerize to form multivalent aggregates with the J chain. In the case of IgG, the four-chain unit typically measures approximately 150,000 daltons. Each light chain contains an N-terminal variable (V) domain (VL) and a constant (C) domain (CL). Each heavy chain contains an N-terminal V domain (VH), three or four C domains (CH), and a hinge region. The constant domains are not directly involved in binding the antibody to an antigen, but can exhibit various effector functions, such as antibody-dependent cellular cytotoxicity (ADCC).If the antibody is required to exert ADCC, it is preferably of the IgG1 subtype, as the IgG4 subtype will not be able to exert ADCC.

[0023] The term "antibody" also encompasses, but is not limited to, monoclonal antibodies, single-specific antibodies; multispecific or polyspecific antibodies such as bispecific antibodies; humanized antibodies, camelized antibodies, human antibodies, single-chain antibodies, chimeric antibodies, synthetic antibodies, recombinant antibodies, hybrid antibodies, mutated antibodies, grafted antibodies, and antibodies produced in vitro; chimeric or humanized antibodies are preferred. The term "humanized antibody" is generally defined as an antibody in which the CDRs encoding the specificity of the HC and LC have been grafted onto an appropriate human variable framework ("CDR-grafted"). The term "antibody" also includes scFvs, single-chain antibodies, diabodies or tetrabodies, domain antibodies (dAbs), and nanobodies. Within the context of the present invention, the term "antibody" also includes dimeric, trimeric, multimeric, or bifunctional, trifunctional, or multifunctional antibodies having several antigen-binding sites.

[0024] Furthermore, the term "antibody," as used in the present invention, also relates to derivatives of the antibodies (including fragments) described herein. A "derivative" of an antibody includes an amino acid sequence that has been altered by the introduction of substitutions, deletions, or additions of amino acid residues. Furthermore, derivatives also encompass antibodies that have been modified by covalently binding any type of molecule to the antibody or protein. Examples of such molecules include, but are not limited to, sugars, PEG, hydroxyl groups, ethoxy groups, carboxy groups, or amine groups. Indeed, covalent modifications of antibodies can result in, but are not limited to, glycosylation, pegylation, acetylation, phosphorylation, and amidation.

[0025] The antibodies of the present invention are preferably "isolated" antibodies. "Isolated," when used to describe the antibodies disclosed herein, refers to an antibody that has been identified, separated, and / or recovered from components of its production environment. Preferably, an isolated antibody is free from all other components from its production environment. Contaminating components from the production environment, such as those resulting from recombinantly transfected cells, are substances that would typically interfere with the diagnostic or therapeutic use of the polypeptide and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes. In preferred embodiments, the antibody is purified (1) sufficiently to obtain at least 15 residues of N-terminal or internal amino acid sequence using a spinning cup sequencer, or (2) to a degree that renders the antibody homogeneous by SDS-PAGE under non-reducing or reducing conditions, using Coomassie blue staining or, preferably, silver staining. However, typically, an isolated antibody is prepared by at least one purification step.

[0026] The antibodies described herein can be used for diagnostic purposes, including sample testing and in vivo imaging. For this purpose, the antibody (or its binding fragment) can be conjugated to an appropriate detectable substance to form an immunoconjugate. For diagnostic purposes, suitable substances are detectable labels, including radioisotopes for whole-body imaging and radioisotopes for sample testing, enzymes, fluorescent labels, and other suitable antibody tags. The detectable label can be any of a variety of types currently used in the field of in vitro diagnostics, including particulate labels including metal sols such as colloidal gold; isotopes; chromophores including fluorescent markers, biotin, luminescent markers, and phosphorescent markers, as well as enzyme labels that convert a given substrate into a detectable marker; and polynucleotide tags that become apparent after amplification, such as by polymerase chain reaction. In this case, biotinylated antibodies will be detectable by avidin or streptavidin binding. Suitable enzyme labels include horseradish peroxidase and alkaline phosphatase. For example, the label can be the enzyme alkaline phosphatase, which is detected by measuring the presence or formation of chemiluminescence following conversion of a 1,2 dioxetane substrate (e.g., adamantylmethoxyphosphoryloxyphenyl dioxetane (AMPPD), 3-(4-(methoxyspiro{1,2-dioxetane-3,2'-(5'-chloro)tricyclo{3.3.1.1 3,7}decan}-4-yl)phenylphosphate disodium (CSPD), and CDP and CDP-star®), or other luminescent substrates well known to those of skill in the art, e.g., chelates of suitable lanthanides such as terbium(III) and europium(III). The means of detection will depend on the label selected. The appearance of the label or its reaction products can be determined visually if the label is particulate and accumulates at an appropriate level, or can be determined using instruments such as spectrophotometers, luminometers, and fluorometers, all according to standard practices.

[0027] An "effector function" of an antibody refers to a biological activity attributable to the Fc region of the antibody (a native sequence Fc region or an amino acid sequence variant Fc region), which varies depending on the antibody isotype. Examples of antibody effector functions include C1q binding and complement-dependent cytotoxicity (CDC); Fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g., B cell receptors); and B cell activation. Antibodies essentially recruit effector cells to perform their effector functions.

[0028] As used herein, the term "antigen-binding portion" refers to a fragment of an immunoglobulin (or intact antibody) and includes any polypeptide containing an antigen-binding fragment or antigen-binding domain. Preferably, the fragment is, for example, Fab, F(ab'), F(ab')2, Fv, scFv, Fd, disulfide-linked Fv (sdFv), and other antibody fragments that retain the antigen-binding function described herein. Typically, such fragments contain the antigen-binding domain and are expected to have the same properties as the antibodies described herein. Thus, the fragment is preferably also capable of binding to the extracellular domain of NaPi2b.

[0029] As used herein, the term "specifically binds" refers to an antibody or a fragment or derivative thereof that specifically binds to the NaPi2b protein and does not specifically bind to another protein. The antibody or a fragment or derivative thereof according to the present invention binds to the NAPI2B protein via the variable domain of the antibody.

[0030] The VH and VL domains pair together to form a single antigen-binding site. The CH domain closest to the VH is called CH1. Each L chain is linked to an H chain by one covalent disulfide bond, while the two H chains are linked to each other by one or more disulfide bonds depending on the H chain isotype. The VH and VL domains consist of four regions with relatively conserved sequences called framework regions (FR1, FR2, FR3, and FR4), which form a scaffold for three regions with hypervariable sequences (complementarity-determining regions, CDRs). The CDRs contain most of the residues responsible for the specific interaction between the antibody and the antigen. The CDRs are called CDR1, CDR2, and CDR3. Thus, the CDR components on the heavy chain are referred to as H1 or H-CDR1 (or CRD-H1), H2 or H-CDR2 (or CDR-H2), and H3 or H-CDR3 (or CDR-H3), while the CDR components on the light chain are referred to as L1 or L-CDR1 (or CRD-L1), L2 or L-CDR2 (or CDR-L2), and L3 or L-CDR3 (or CDR-L3).

[0031] The term "variable" refers to that portion of an immunoglobulin domain (i.e., the "variable domain") that exhibits sequence variability and is responsible for determining the specificity and binding affinity of an individual antibody. The variability is not evenly distributed throughout the variable domains of antibodies, but is concentrated in subdomains of each of the heavy and light chain variable regions. These subdomains are called "complementarity-determining regions" (CDRs).

[0032] The term "CDR" and its plural form "CDRs" refer to complementarity-determining regions (CDRs), three of which make up the binding characteristics of the light chain variable region (L1-CDR, L2-CDR, and L3-CDR) and three of which make up the binding characteristics of the heavy chain variable region (H1-CDR, H2-CDR, and H3-CDR). CDRs contribute to the functional activity of an antibody molecule and are separated by amino acid sequences that constitute scaffolding or framework regions. The precise boundaries and lengths of CDRs vary among various classification and numbering systems. Thus, CDRs may be referred to based on Kabat, Chothia, contact definitions, or any other boundary definition, including the numbering systems described herein. Although the boundaries differ, each of these systems has some overlap in the elements that constitute the so-called "hypervariable regions" within the variable sequence. Therefore, CDR definitions based on these systems may differ in terms of length and interface regions with adjacent framework regions. However, numbering according to the so-called Kabat system is preferred.

[0033] The highly conserved (i.e., non-hypervariable) portions of the variable domain are called "framework" regions (FRMs). Natural heavy and light chain variable domains each contain four FRM regions, which are primarily arranged in a β-sheet configuration and connected by three hypervariable regions, which form loops to connect and, in some cases, form part of the β-sheet structure. The hypervariable regions of each chain are held together in close proximity by the FRMs and, together with the hypervariable regions of the other chain, contribute to the formation of the antigen-binding surface (see Kabat et al., supra). The constant domains are not directly involved in antigen binding but exhibit various effector functions, such as antibody-dependent cell-mediated cytotoxicity and complement activation.

[0034] The term "binding domain" in the context of the present invention characterizes a domain of a polypeptide that specifically binds / interacts with a given target epitope. An "epitope" is antigenic, and therefore the term epitope is also sometimes referred to herein as an "antigenic structure" or "antigenic determinant". A binding domain is therefore an "antigen interaction site". The term "antigen interaction site" defines, according to the present invention, a motif of a polypeptide that can specifically interact with a particular antigen or a particular group of antigens, for example, the same antigen in different species. It is also understood that this binding / interaction defines "specific recognition".

[0035] The terms "antigen-binding domain," "antigen-binding portion," "antigen-binding fragment," and "antibody-binding region," as used herein, refer to a portion of an antibody molecule comprising amino acids responsible for the specific binding between the antibody and an antigen. The portion of an antigen that is specifically recognized and bound by an antibody is called an "epitope," as described above. As described above, an antigen-binding domain may typically comprise an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH).

[0036] The term "epitope" also refers to a site on an antigen (in the context of the present invention, the antigen is the NaPi2b protein) to which an antibody molecule binds. Preferably, an epitope is a site on a molecule (in the context of the present invention, the antigen is the NaPi2b protein) against which an antibody or its antigen-binding portion, preferably an antibody, is raised and / or to which an antibody binds. For example, an epitope can be recognized by an antibody or its antigen-binding portion. A "linear epitope" is an epitope in which the primary amino acid sequence constitutes the recognized epitope. Typically, a linear epitope contains at least three, and more usually at least five, e.g., about 8 to about 10, amino acids in a unique sequence.

[0037] The term "cross-reactivity" may refer to the ability of antibodies to react with similar antigenic sites on different proteins.

[0038] The term "specific" in this context can mean that the antibody or its antigen-binding portion binds to the target NaPi2b but does not bind to another protein. The term "another protein" includes any protein, including proteins that are closely related to or homologous to the NAPI2B protein to which the antibody or its antigen-binding portion is directed. However, the term "another protein" does not include cross-reactivity of an antibody or its antigen-binding portion with a NaPi2b protein from a species different from the species in which the antibody or its antigen-binding portion was generated.

[0039] Thus, cross-species specific antibodies or antigen-binding portions thereof directed against NaPi2b protein are preferably contemplated by the present invention.

[0040] "K D " refers to the equilibrium dissociation constant, i.e., k between an antibody and its antigen, or between the variable regions of one heavy chain and one light chain of an antibody or fragment or derivative thereof and their antigen. off / k onwherein the antigen is, for example, Napi2b, e.g., full-length Napi2b and / or one or more fragments thereof, preferably the one or more fragments comprising at least one extracellular domain (ECD) of the Napi2b (e.g., the ECD comprising amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1) and / or one or more fragments of the ECD (e.g., having a length of about 15 to about 30 amino acids); for example, the full-length Napi2b and / or the one or more fragments thereof are fused or unfused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST); D is measured in vitro. D and affinity are inversely proportional to each other.

[0041] As used herein, the term "affinity" may refer to the strength of binding between the variable regions of one heavy chain and one light chain of an antibody, or a fragment or derivative thereof, and its antigen; wherein the antigen is, for example, Napi2b, e.g., full-length Napi2b and / or one or more fragments thereof, preferably the one or more fragments bind to at least one extracellular domain (ECD) of Napi2b (e.g., the ECD is set forth in SEQ ID NO: The antibody comprises a full-length Napi2b (containing amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having an ECD of 1 or more fragments thereof (e.g., having a length of about 15 to about 30 amino acids); for example, the full-length Napi2b and / or one or more fragments thereof may be fused or unfused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST); and affinity is measured in vitro. Affinity reveals the strength of interaction between an epitope and the antigen-binding site of an antibody. Affinity can be calculated using the following formula: KA=[AB-AG] / [AB]×[AG]=k on / k off During the ceremony, KA = affinity constant [AB] = molar concentration of open binding sites on the antibody [AG] = molar concentration of open binding sites on the antigen [AB-AG] = molar concentration of antibody-antigen complex

[0042] The term "amino acid" or "amino acid residue" typically refers to an amino acid having an art-recognized definition, e.g., an amino acid selected from the group consisting of alanine (Ala or A); arginine (Arg or R); asparagine (Asn or N); aspartic acid (Asp or D); cysteine ​​(Cys or C); glutamine (Gln or Q); glutamic acid (Glu or E); glycine (Gly or G); histidine (His or H); isoleucine (He or I); leucine (Leu or L); lysine (Lys or K); methionine (Met or M); phenylalanine (Phe or F); proline (Pro or P); serine (Ser or S); threonine (Thr or T); tryptophan (Trp or W); tyrosine (Tyr or Y); and valine (Val or V), although modified, synthetic, or rare amino acids may also be used if desired. Generally, amino acids can be grouped as having nonpolar side chains (e.g., Ala, Cys, He, Leu, Met, Phe, Pro, Val); negatively charged side chains (e.g., Asp, Glu); positively charged side chains (e.g., Arg, His, Lys); or uncharged polar side chains (e.g., Asn, Cys, Gln, Gly, His, Met, Phe, Ser, Thr, Trp, and Tyr).

[0043] The term "polypeptide" is used herein equivalently to the term "protein." Proteins (including fragments thereof, preferably biologically active fragments, and peptides usually having fewer than 30 amino acids) contain one or more amino acids linked to each other via covalent peptide bonds (resulting in a chain of amino acids). The term "polypeptide," as used herein, refers to a group of molecules, for example, consisting of more than 30 amino acids. Polypeptides may also form multimers, such as dimers, trimers, and higher-order oligomers, i.e., consisting of multiple polypeptide molecules. The polypeptide molecules forming such dimers, trimers, etc. may be identical or non-identical. Consequently, the corresponding higher-order structures of such multimers are called homodimers or heterodimers, homotrimers or heterotrimers, etc. An example of a heteromultimer is an antibody molecule, which in its natural form consists of two identical light polypeptide chains and two identical heavy polypeptide chains. The terms "polypeptide" and "protein" also refer to naturally modified polypeptides / proteins that have been modified by post-translational modifications such as, for example, glycosylation, acetylation, and phosphorylation. Such modifications are well known in the art.

[0044] The term "immune cell" refers to a cell capable of producing an antibody. Immune cells of particular interest herein are lymphoid cells derived from, for example, the spleen, peripheral blood lymphocytes (PBL), lymph nodes, inguinal lymph nodes, Peyer's patches, tonsils, bone marrow, umbilical cord blood, pleural effusion, and tumor-infiltrating lymphocytes (TIL).

[0045] One type of antibody variant encompassed by the present invention is an amino acid substitution variant, in which at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid residues in the Napi2b antibody molecule are replaced with different residues. The sites of greatest interest for substitutional mutagenesis include the CDRs of the heavy and / or light chains, particularly the hypervariable regions, although alterations of the FRs of the heavy and / or light chains are also contemplated.

[0046] For example, if a CDR sequence contains 6 amino acids, it is contemplated that 1, 2, or 3 of these amino acids may be substituted. Similarly, if a CDR sequence contains 15 amino acids, it is contemplated that 1, 2, 3, 4, 5, or 6 of these amino acids may be substituted.

[0047] Generally, when amino acids are substituted in one or more or all of the CDRs of the heavy and / or light chain, the resulting "substituted" sequence is preferably at least 60% (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to the "original" CDR sequence, more preferably 65%, even more preferably 70%, particularly preferably 75%, and even more particularly preferably 80% identical. This means that the degree to which a CDR is identical to a "substituted" sequence depends on the length of the CDR. For example, a CDR having five amino acids is preferably 80% identical to its substituted sequence in order for at least one amino acid to be substituted. Thus, the CDRs of the Napi2b antibody may have varying degrees of identity to their substituted sequences, for example, CDRL1 may have 80% identity, while CDRL3 may have 90% identity.

[0048] Preferred substitutions (or replacements) are conservative substitutions. However, any substitution (including non-conservative substitutions or one or more of the "exemplary substitutions" listed in Table I herein) is contemplated, as long as the antibody retains the ability to specifically bind to the Napi2b protein and / or its CDRs have identity to the substituted sequence (at least 60% (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%), more preferably 65%, even more preferably 70%, particularly preferably 75%, and even more particularly preferably 80% identical to the "original" CDR sequence).

[0049] Conservative substitutions are shown under the heading "preferred substitutions" in Table I. If such substitutions result in altered biological activity, more substantial changes, designated "exemplary substitutions" in Table I or further described below in relation to amino acid classes, may be introduced and the products screened for desired characteristics.

[0050] chemical modification Antibodies or antigen-binding variants or fragments thereof used in accordance with the present invention may be modified. Typical modifications contemplated in the context of the present invention include, for example, chemical modifications as described below.

[0051] Chemical modifications that can be performed on antibodies or their antigen-binding variants or fragments include acylation or acetylation of the amino terminus, or amidation or esterification of the carboxy terminus, or such modifications at both termini. Modifications can also affect the amino group of the side chain of lysine or the hydroxyl group of threonine. Other suitable modifications include, for example, extension of amino groups with polypeptide chains of various lengths (e.g., XTEN technology or PASylation®), N-glycosylation, O-glycosylation, and chemical attachment of carbohydrates, such as hydroxyethyl starch (e.g., HESylation®) or polysialic acid (e.g., PolyXen® technology). Chemical modifications such as alkylation (e.g., methylation, propylation, butylation), arylation, and etherification may also be possible and are also contemplated.

[0052] Antibody Drug Conjugates (ADCs) The term antibody drug conjugate (or ADC), as used herein, may refer to any antibody according to the present invention conjugated to one or more drug moieties (e.g., cytotoxic payloads). Preferably, the antibody drug conjugates (ADCs) of the present invention comprise an anti-Napi2b antibody of the present invention (e.g., a humanized monoclonal Napi2b-specific IgG1 antibody) conjugated to one or more cytotoxic payloads, wherein (a) the cytotoxic payload is selected from the group consisting of camptothecin, maytansinoid, calicheamicin, duocarmycin, tubulysin, amatoxin, dolastatin, and auristatin, e.g., monomethylauristatin E (MMAE), pyrrolidin, thiazolinone ... and / or (b) the cytotoxic payload is selected from the group consisting of exatecan (e.g., CAS No. 171335-80-1), DXD, SN38, camptothecin, topotecan, irinotecan, irinotecan, irinotecan-1, irinotecan-2, irinotecan-3, irinotecan-4, irinotecan-5, irinotecan-6, irinotecan-7, irinotecan-8, irinotecan-9, irinotecan-10, irinotecan-11, irinotecan-12, irinotecan-13, irinotecan-14, irinotecan-15, irinotecan-16, irinotecan-17, irinotecan-18, irinotecan-19, irinotecan-20, irinotecan-21, irinotecan-22, irinotecan-23, irinotecan-24, irinotecan-25, irinotecan-26, irinotecan-27, irinotecan-28, irinotecan-29, irinotecan-30, irinotecan-31, irinotecan-32, irinotecan-33, irinotecan-34, irinotecan-35, irinotecan-36, irinotecan-37, irinotecan-38, irinotecan-40, irinotecan-41, irinotecan-42, irinotecan-43, irinotecan-44, irinotecan-45, irinotecan-46, irinotecan-47, irinotecan-48, irinotecan-49, irinotecan-50, irinotecan-51, irinotecan-52, irinotecan-53, irinotecan-54, irinotecan-55, irinotecan-55, irinotecan-5 and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker (L) comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, wherein the releasing unit is cleavable by a protease.As used herein, "linker" (L) may mean any chemical moiety capable of linking an antibody of the invention to one or more drug moieties (e.g., a cytotoxic moiety (e.g., a cytotoxic payload, such as a tubulin inhibitor, e.g., a topoisomerase-I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan). Preferably, L is a phosphoamidate linker; more preferably, linker L comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; most preferably, linker L is cleavable (e.g., susceptible to enzymatic cleavage).

[0053] Sequence identity The term "percent identity" or "percent sequence identity" as used herein may refer to the percentage of pairwise identical residues relative to the number of residues in the longer of the two sequences after aligning (homology) the sequence of a polypeptide of the present invention with the sequence in question. The percent identity is calculated by dividing the number of identical residues by the total number of residues and multiplying the result by 100.

[0054] The percentage of sequence homology or sequence identity can be determined herein, for example, using BLASTP, version blastp 2.2.5 (November 16, 2002; Altschul, SF et al. (1997) Nucl. Acids Res. 25, 3389-3402). In this embodiment, the percentage of homology is preferably based on the alignment of the entire polypeptide sequence, including the propeptide sequence, using the wild-type protein backbone as a reference in pairwise comparison (matrix: BLOSUM 62; gap cost: 11.1). It is calculated as the percentage of the number of "positives" (homologous amino acids) shown as the result in the BLASTP program output divided by the total number of amino acids selected by the program for alignment.

[0055] The term "Napi2b" refers to sodium-dependent phosphate transport protein 2B, and generally includes all known isoforms. Preferably, the sodium-dependent phosphate transport protein 2B has SEQ ID NO: 1 or UniProtKB Accession No. O95436.

[0056] vector The nucleic acids of the invention may also be in the form of, present within and / or part of a vector.

[0057] The term "vector" refers to a nucleic acid molecule used as a vehicle for transferring (foreign) genetic material into a host cell, and includes, but is not limited to, plasmids, viruses, cosmids, and artificial chromosomes, such as bacterial artificial chromosomes (BACs) and yeast artificial chromosomes (YACs). A designed vector typically contains an origin of replication, a multiple cloning site, and a selection marker. The vector itself is typically a nucleotide sequence, usually a DNA sequence, that contains an insert (transgene) and a larger sequence that serves as the "backbone" of the vector. In addition to the transgene insert and backbone, a vector may contain additional elements, including genetic control elements, genetic markers, antibiotic resistance, reporter genes, targeting sequences, or protein purification tags. Specifically contemplated in the context of the present invention are expression vectors (expression constructs) for expressing a transgene in a host cell, which typically contain genetic control sequences in addition to the transgene.

[0058] Generally, an expression vector is one that is capable of expressing an antibody of the invention in vitro and / or in vivo (i.e., in an appropriate host cell, host organism, and / or expression system). One of skill in the art will readily understand that the selection of a particular vector will depend on factors including, for example, the host cell, the intended copy number of the vector, whether transient or stable expression of the antibody of the invention is envisioned, etc.

[0059] "Transient expression" occurs by introducing a nucleic acid (e.g., a linear or non-linear DNA or RNA molecule) or vector that is incapable of autonomous replication into a recipient host cell. Expression of the transgene occurs through the transient expression of the introduced sequence.

[0060] However, "stable expression" of the nucleic acid sequences described herein is often preferred, and this may be achieved by stably integrating the nucleic acid sequence into the genome of the host cell, or by introducing into the host cell a vector capable of autonomous replication that contains a nucleic acid sequence of the invention.

[0061] It is specifically contemplated that the vectors provided herein contain genetic control elements operably linked to a DNA sequence encoding an antibody of the invention.

[0062] The term "genetic control element" refers to a DNA sequence necessary for the expression of an operably linked coding sequence in a particular host organism. The term "genetic control element" includes other elements that can control gene expression, including controllable transcriptional promoters, operators, enhancers, silencers, transcription terminators, 5' and 3' untranslated regions, and start and stop codons that interact with host cellular proteins to carry out transcription and translation. The exact nature of the control regions required for gene expression can vary from organism to organism. Genetic control elements in prokaryotes include, for example, a promoter, optionally an operator sequence, and a ribosome binding site (RBS), whereas genetic control elements in eukaryotic cells include a promoter, a polyadenylation (polyA) signal, and an enhancer.

[0063] A genetic control element is considered to be "operably linked" to a gene to be expressed, i.e., positioned so as to be functionally related to that gene. For example, a promoter or enhancer is "operably linked" to a coding nucleic acid sequence if it affects the transcription of that sequence. DNA sequences that are "operably linked" may or may not be contiguous. Linking is typically accomplished by ligation at convenient restriction sites or by synthetic oligonucleotide adapters or linkers.

[0064] host cell Additionally, host cells (eg, recombinant host cells and / or isolated host cells) comprising the vectors described herein are also provided herein.

[0065] Various host cells can be used to express the nucleic acid sequences encoding the antibodies described herein. Host cells can be prepared using genetic engineering methods known in the art. The process of introducing a vector into a recipient host cell is also referred to below as "transformation" or "transfection." These terms are used interchangeably herein.

[0066] Transformation of host cells typically involves creating temporary pores or "holes" in the cell wall and / or membrane to allow for the uptake of substances. Illustrative examples of transformation protocols include the use of calcium phosphate, electroporation, cell compaction, dendrimers, liposomes, cationic polymers such as DEAE-dextran or polyethyleneimine, sonoporation, optical transfection, impale infection, nanoparticles (gene guns), magnetofection, microprojectile bombardment, alkaline cations (cesium, lithium), enzymatic digestion, agitation with glass beads, or viral vectors. The choice of method usually depends on the type of cell to be transformed, the vector to be introduced into the cell, and the conditions under which the transformation is to be performed.

[0067] As used herein, the term "host cell" can refer to any cell or cell culture that can serve as a recipient for a vector or isolated nucleic acid sequence encoding an antibody (Ab) as described herein. Suitable host cells include prokaryotic or eukaryotic cells, and also include, but are not limited to, bacteria, yeast cells, fungal cells, plant cells, and animal cells, such as insect cells and mammalian cells, such as mouse, rat, macaque, or human cells.

[0068] For example, antibodies (Abs) can be produced in bacteria. In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable hosts for cloning or expression of NAPI2B antibodies of the invention. Illustrative examples include Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces hosts such as K. lactis, K. fragilis (ATCC 12424), K. bulgaricus (ATCC 16045), K. wickeramii (ATCC 24178), K. waltii (ATCC 56500), K. drosophilarum (ATCC 36906), K. thermotolerans, and K. marxianus; Yarrowia (EP 402 226); Pichia pastoris (EP 183 070); Candida; Trichoderma reesia (EP 244 234); Neurospora crassa; Schwanniomyces, such as Schwanniomyces occidentalis; and filamentous fungal hosts, such as Neurospora, Penicillium, Tolypocladium, and Aspergillus, such as A. nidulans and A. niger.

[0069] Suitable host cells for expression of the glycosylated antibody constructs of the present invention may also be derived from multicellular organisms. Examples of invertebrate cells include plant cells and insect cells. Numerous baculovirus strains and variants have been identified, as well as corresponding permissive insect host cells derived from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruit fly), and Bombyx mori (silkworm). Various virus strains for transfection, such as the L-1 variant of Autographa californica NPV and the Bm-5 strain of silkworm NPV, are publicly available.

[0070] Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, Arabidopsis, and tobacco can also be used as hosts. Cloning and expression vectors useful for the production of proteins in plant cell culture are known to those of skill in the art.

[0071] Examples of useful mammalian host cell lines are the SV40-transformed monkey kidney CV1 line (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cells subcloned to grow in suspension culture); baby hamster kidney cells (BHK, ATCC CCL 10); Chinese hamster ovary cells / -DHFR (CHO), mouse Sertoli cells (TM4); monkey kidney cells (CVI ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL 1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat hepatocytes (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human hepatocytes (Hep G2, 1413 8065); mouse mammary tumor (MMT 060562, ATCC CCL51); TRI cells; MRC 5 cells; FS4 cells; and human hepatocellular carcinoma cells (Hep G2).

[0072] patient The term "patient" or "subject" as used herein refers to a human or non-human animal, typically a mammal.Specifically considered are mammals, such as rabbits, mice, rats, guinea pigs, hamsters, dogs, cats, pigs, cows, goats, sheep, horses, monkeys, apes, or preferably humans.Therefore, the methods, uses, and compounds described in this document are generally applicable to both human and veterinary diseases.

[0073] treatment The term "treatment," in all its grammatical forms, includes therapeutic or prophylactic treatment. "Therapeutic or prophylactic treatment" includes prophylactic treatment aimed at completely preventing clinical and / or pathological symptoms, or therapeutic treatment aimed at ameliorating or ameliorating clinical and / or pathological symptoms of disease. Thus, the term "treatment" also includes ameliorating or preventing cancer.

[0074] In the present invention, the term "therapeutic effect" generally refers to the desired or beneficial effects of treatment, such as the improvement or amelioration of disease symptoms. The term "symptoms" of a disease is used herein to describe its perceptible manifestations, and includes both clinical symptoms (defined below as signs of disease that may be detected during a physical examination and / or are perceptible to the patient (i.e., subjective symptoms)) and pathological symptoms, meaning the manifestations of disease at the cellular and molecular levels. The therapeutic effect of treatment with the NaPi2b-ADC of the present invention can be evaluated using routine methods in the art, for example, by measuring the leukemia burden by blood / bone marrow analysis (cytomorphology, flow cytometry, genetics), clinical chemistry, or radiological techniques (e.g., CT). Additionally or alternatively, the overall appearance (e.g., health status, well-being) of each patient can also be evaluated, which also helps a skilled physician assess whether a therapeutic effect has been elicited. Those skilled in the art will be aware of numerous other methods suitable for monitoring the therapeutic effect of the compounds of the present invention.

[0075] dose Preferably, a therapeutically effective amount of a compound described herein is administered. By "therapeutically effective amount" is meant an amount of a compound described herein that elicits a therapeutic effect. The exact dose of the Ab-NaPi2b-ADC of the present invention depends on the purpose of treatment (e.g., remission induction, maintenance) and can be ascertained by one of ordinary skill in the art using known techniques. Adjustments may be necessary depending on the route of administration, age, body weight, general health, sex, diet, time of administration, drug interactions, and severity of the condition, which can be ascertained by one of ordinary skill in the art through routine experimentation.

[0076] Administration Various routes are applicable for administering the compounds according to the invention, including but not limited to oral, topical, transdermal, subcutaneous, intravenous, intraperitoneal, intramuscular, or intraocular, preferably subcutaneous and / or intravenous, although those skilled in the art can easily select any other route if desired.

[0077] composition It is contemplated that the NAPI2B antibodies and / or ADCs of the invention will be administered in the form of a pharmaceutical composition.

[0078] The term "pharmaceutical composition" specifically refers to a composition suitable for administration to humans, i.e., a composition that is preferably sterile and / or contains pharmaceutically acceptable ingredients. However, compositions suitable for administration to non-human animals are also contemplated herein. Preferably, a pharmaceutical composition comprises the Ab-NaPi2b-ADC of the present invention together with one or more pharmaceutical excipients. The term "excipient" includes a filler, binder, disintegrant, coating agent, adsorbent, antiadherent, glidant, preservative, antioxidant, flavoring agent, colorant, sweetener, solvent, cosolvent, buffer, chelating agent, viscosity-imparting agent, surfactant, diluent, wetting agent, carrier, diluent, preservative, emulsifier, stabilizer, or osmolality-adjusting agent. The pharmaceutical compositions of the present invention can be formulated in various forms, for example, solid, liquid, gaseous, or lyophilized forms; among others, they may be in the form of ointments, creams, transdermal patches, gels, powders, tablets, solutions, aerosols, granules, pills, suspensions, emulsions, capsules, syrups, solutions, elixirs, extracts, tinctures, or liquid extracts, or any form particularly suited to the desired method of administration.

[0079] The pharmaceutical compositions of the present invention may further comprise one or more additional agents. Preferably, these agents are therapeutically effective for the treatment of the diseases described herein and are present in the composition in therapeutically effective amounts.

[0080] Accordingly, in view of the above, the present invention also provides pharmaceutical compositions comprising one or more NaPi2b antibodies and / or ADCs of the invention, which are particularly intended for use in methods for the therapeutic and / or prophylactic treatment of cancer.

[0081] kit Kits are also provided herein.The kits may be two- or more-part kits, and the kits preferably contain the NaPi2b antibodies and / or ADCs of the present invention in therapeutically effective amounts and in pharmaceutically acceptable forms.The components of the kits may be placed in containers or vials.It is envisioned that the kits may contain additional agents useful for the treatment of cancer.

[0082] chemical group Unless otherwise specified, the term "alkyl," by itself or as part of another term, generally refers to a substituted or unsubstituted straight- or branched-chain saturated hydrocarbon having the specified number of carbon atoms; for example, "-(C1-C8) alkyl" or "-(C1-C 10 ") alkyl" refers to an alkyl group having 1 to 8 or 1 to 10 carbon atoms, respectively. If the number of carbon atoms is not specified, the alkyl group may have 1 to 8 carbon atoms. Representative straight-chain -(C1-C8) alkyl groups include, but are not limited to, -methyl, -ethyl, -n-propyl, -n-butyl, -n-pentyl, -n-hexyl, -n-heptyl, and -n-octyl, and branched-chain -(C1-C8) alkyl groups include, but are not limited to, -isopropyl, -sec-butyl, -isobutyl, -tert-butyl, -isopentyl, and -2-methylbutyl. In some aspects, an alkyl group can be unsubstituted. Optionally, an alkyl group can be substituted, for example with one or more groups.

[0083] Unless otherwise specified, the term "alkylene" by itself or as part of another term generally refers to an alkylene group having the stated number of carbon atoms, preferably 1 to 10 carbon atoms (-(C1-C 10(-C1-C8)alkylene-) or preferably 1 to 8 carbon atoms (-(C1-C8)alkylene-), and having two monovalent radical centers derived from the removal of two hydrogen atoms from the same or two different carbon atoms of a parent alkane. If the number of carbon atoms is not specified, the alkylene group may have 1 to 8 carbon atoms. Typical alkylene radicals include, but are not limited to, methylene (-CH2-), 1,2-ethylene (-CH2CH2-), 1,3-n-propylene (-CH2CH2CH2-), and 1,4-n-butylene (-CH2CH2CH2CH2-). In some aspects, an alkylene group can be unsubstituted. Optionally, an alkylene group can be substituted, for example with one or more groups.

[0084] Unless otherwise specified, the term "alkenyl," by itself or as part of another term, generally means a substituted or unsubstituted straight or branched chain unsaturated hydrocarbon having a double bond and the specified number of carbon atoms; for example, "-(C2-C8)alkenyl" or "-(C2-C 10 "-(C2-C8)alkenyl" refers to an alkenyl group having 2 to 8 or 2 to 10 carbon atoms, respectively. If the number of carbon atoms is not specified, the alkenyl group may have 2 to 8 carbon atoms. Representative -(C2-C8)alkenyl groups include, but are not limited to, -ethenyl, -1-propenyl, -2-propenyl, -1-butenyl, -2-butenyl, -isobutenyl, -1-pentenyl, -2-pentenyl, -3-methyl-1-butenyl, -2-methyl-2-butenyl, and -2,3-dimethyl-2-butenyl. In some aspects, an alkenyl group can be unsubstituted. Optionally, an alkenyl group can be substituted, for example with one or more groups.

[0085] Unless otherwise specified, the term “alkenylene,” by itself or as part of another term, generally refers to an alkenylene having the stated number of carbon atoms, preferably 2 to 10 carbon atoms (—(C 10 (C2-C8)alkenylene-) or preferably 2 to 8 carbon atoms (-(C2-C8)alkenylene-), and having a double bond and two monovalent radical centers formed by the removal of two hydrogen atoms from the same or two different carbon atoms of a parent alkene. If the number of carbon atoms is not specified, the alkenylene group may have 2 to 8 carbon atoms. Typical alkenylene radicals include, but are not limited to, -ethenylene-, -1-propenylene-, 2-propenylene-, -1-butenylene-, -2-butenylene-, -isobutenylene-, -1-pentenylene-, -2-pentenylene-, -3-methyl-1-butenylene-, -2-methyl-2-butenylene-, and -2,3-dimethyl-2-butenylene-. In some aspects, an alkenylene group can be unsubstituted. Optionally, an alkenylene group can be substituted, for example with one or more groups.

[0086] Unless otherwise specified, the term "alkynyl," by itself or as part of another term, generally means a substituted or unsubstituted straight or branched chain unsaturated hydrocarbon having a triple bond and the specified number of carbon atoms; for example, "-(C2-C8)alkynyl" or "-(C2-C 10"-(C2-C8)alkynyl" refers to an alkynyl group having 2 to 8 or 2 to 10 carbon atoms, respectively. If the number of carbon atoms is not specified, the alkynyl group may have 2 to 8 carbon atoms. Representative -(C2-C8)alkynyl groups include, but are not limited to, -acetylenyl, -1-propynyl, -2-propynyl, -1-butynyl, -2-butynyl, -1-pentynyl, -2-pentynyl, and -3-methyl-1-butynyl. In some aspects, an alkynyl group can be unsubstituted. Optionally, an alkynyl group can be substituted, for example with one or more groups.

[0087] Unless otherwise stated, the term "alkynylene," by itself or as part of another term, generally refers to an alkynylene having a recited number of carbon atoms, preferably 2 to 10 carbon atoms (-(C-C 10 (C2-C8)alkynylene-) or preferably 2 to 8 carbon atoms (-(C2-C8)alkynylene-), and a substituted or unsubstituted branched or straight-chain unsaturated hydrocarbon radical having a triple bond and two monovalent radical centers formed by the removal of two hydrogen atoms from the same or two different carbon atoms of a parent alkyne. If the number of carbon atoms is not specified, the alkynylene group can have 2 to 8 carbon atoms. Typical alkynylene radicals include, but are not limited to, -ethynylene-, -1-propynylene-, -2-propynylene-, -1-butynylene-, -2-butynylene-, -1-pentynylene-, -2-pentynylene-, and -3-methyl-1-butynylene-. In some aspects, an alkynylene group can be unsubstituted. Optionally, an alkynylene group can be substituted, for example with one or more groups.

[0088] Unless otherwise specified, the term "aryl," by itself or as part of another term, generally refers to a substituted or unsubstituted monovalent carbocyclic aromatic hydrocarbon radical having 6 to 20 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms, and in a highly preferred embodiment, 6 carbon atoms) derived by removing one hydrogen atom from a carbon atom of a parent aromatic ring system. Some aryl groups are represented in the exemplary structures as "Ar." Typical aryl groups include, but are not limited to, radicals derived from benzene, substituted benzene, naphthalene, anthracene, and biphenyl. An exemplary aryl group is a phenyl group. In some aspects, an aryl group can be unsubstituted. Optionally, an aryl group can be substituted, for example, with one or more groups.

[0089] Unless otherwise specified, the term "arylene," by itself or as part of another term, generally refers to an aryl group, as defined above, in which one of the aryl group's hydrogen atoms has been replaced with a bond (i.e., it is divalent), and has the following structure, with phenyl being an exemplary group: It can be in the para, meta, or ortho configuration, as shown in TIFF2025536308000001.tif17128.

[0090] In selected embodiments, the arylene is an aryl group as defined above, in which two or more of the aryl group's hydrogen atoms are replaced with bonds (i.e., the arylene can be trivalent). In some aspects, the arylene group can be unsubstituted. Optionally, the alkynylene group can be substituted, for example, with one or more groups.

[0091] Unless otherwise specified, the term "heterocycle" or "heterocycle," by itself or as part of another term, generally refers to a ring containing a specified number of carbon atoms (e.g., "(C3-C8)heterocycle" or "(C3-C 10) Heterocycle" means a heterocycle having 3 to 8 or 3 to 10 carbon atoms, respectively) and 1 to 4 heteroatom ring members independently selected from N, O, P, or S, and means a monovalent substituted or unsubstituted aromatic or non-aromatic monocyclic or bicyclic ring system formed by removing one hydrogen atom from a ring atom of the parent ring system. One or more N, C, or S atoms in a heterocycle can be oxidized. A ring containing a heteroatom can be aromatic or non-aromatic. Unless otherwise noted, a heterocycle is attached to its pendant group at any heteroatom or carbon atom that results in a stable structure. Representative examples of (C3-C8)heterocycles include, but are not limited to, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl, benzofuranyl, benzothiophene, indolyl, benzopyrazolyl, pyrrolyl, thiophenyl (thiophene), furanyl, thiazolyl, imidazolyl, pyrazolyl, pyrimidinyl, pyridinyl, pyrazinyl, pyridazinyl, isothiazolyl, and isoxazolyl. In some aspects, heterocyclic groups can be unsubstituted. Optionally, heterocyclic groups can be substituted, for example, with one or more groups.

[0092] Unless otherwise specified, the terms "heterocyclo" or "heterocycle," by themselves or as part of another term, generally refer to a heterocyclic group as defined above and having the specified number of carbon atoms (e.g., (C-C)heterocycle or (C-C 10 ) heterocycle) in which one of the heterocycle group's hydrogen atoms is replaced with a bond (i.e., it is divalent). In selected embodiments, the heterocyclo is a heterocycle group as defined above in which two or more of the heterocycle group's hydrogen atoms are replaced with bonds (i.e., the heterocycle can be trivalent). In some aspects, the heterocyclo or heterocycle can be unsubstituted. Optionally, the heterocyclo or heterocycle can be substituted, for example, with one or more groups.

[0093] Unless otherwise specified, the term "carbocycle" or "carbocyclic" by itself or as part of another term generally refers to a ring system having a specified number of carbon atoms resulting from the removal of one hydrogen atom from a ring atom of a parent ring system (e.g., "(C-C) carbocycle" or "(C-C 10 ")Carbocycle" means a monovalent, substituted or unsubstituted, aromatic or non-aromatic, mono- or bicyclic carbon ring system (meaning a carbocycle having 3 to 8 or 3 to 10 carbon atoms, respectively). As an illustrative, but non-limiting example, a carbocycle can be a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocycle. Representative (C3-C8) carbocycles include, but are not limited to, phenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentadienyl, cyclohexyl, cyclohexenyl, 1,3-cyclohexadienyl, 1,4-cyclohexadienyl, cycloheptyl, 1,3-cycloheptadienyl, 1,3,5-cycloheptatrienyl, cyclooctyl, and cyclooctadienyl. In some aspects, a carbocycle can be unsubstituted. Optionally, a carbocycle can be substituted, e.g., with one or more groups.

[0094] Unless otherwise specified, the term "carbocyclo" or "carbocyclic" by itself or as part of another term generally refers to a ring as defined above and having the specified number of carbon atoms (e.g., "(C-C)carbocyclo" or "(C-C 10")Carbocyclo" refers to a carbocyclic group having 3 to 8 or 3 to 10 carbon atoms, respectively, in which another of the carbocyclic group's hydrogen atoms has been replaced with a bond (i.e., it is divalent). In selected embodiments, a carbocyclo or carbocyclic group is a carbocyclic group as defined above in which two or more of the carbocyclic group's hydrogen atoms have been replaced with bonds (i.e., the carbocyclo or carbocyclic group can be trivalent). In some aspects, a carbocyclo or carbocyclic group can be unsubstituted. Optionally, a heterocyclo or heterocycle can be substituted, e.g., with one or more groups.

[0095] Unless otherwise specified, the term "heteroalkyl," by itself or in combination with other terms, may mean, unless otherwise stated, a stable straight or branched chain hydrocarbon or combination thereof, which is fully saturated or contains 1 to 3 degrees of unsaturation and has the specified number of carbon atoms (e.g., (C1-C8)heteroalkyl or (C1-C 10) heteroalkyl) and 1 to 10, preferably 1 to 3, heteroatoms selected from the group consisting of O, N, Si, and S, where the nitrogen and sulfur atoms are optionally oxidized and the nitrogen heteroatom is optionally quaternized. The heteroatom(s) O, N, and S may be placed at any interior position of the heteroalkyl group or at the position at which the alkyl group is attached to the remainder of the molecule. The heteroatom Si may be placed at any position of the heteroalkyl group, including the position at which the alkyl group is attached to the remainder of the molecule. Examples include -CH2-CH2-O-CH3, -CH2-CH2-NH-CH3, -CH2-CH2-N(CH3)-CH3, -CH2-S-CH2-CH3, -CH2-CH2-S(O)-CH3, -NH-CH2-CH2-NH-C(O)-CH2-CH3, -CH2-CH2-S(O)-CH3, -CH=CH-O-CH3, -Si(CH3)3, -CH2-CH=NO-CH3, and -CH=CH-N(CH3)-CH3. Up to two heteroatoms may be consecutive, for example, -CH2-NH-OCH3 and -CH2-O-Si(CH3)3. In preferred embodiments, the (C1-C4) heteroalkyl or heteroalkylene has 1 to 4 carbon atoms and 1 or 2 heteroatoms, and the (C1-C3) heteroalkyl or heteroalkylene has 1 to 3 carbon atoms and 1 or 2 heteroatoms. In some aspects, the heteroalkyl or heteroalkylene is saturated. In some aspects, the heteroalkyl or heteroalkylene can be unsubstituted. Optionally, the heteroalkyl or heteroalkylene can be substituted, for example, with one or more groups.

[0096] Unless otherwise specified, the term "heteroalkylene," by itself or as part of another substituent, means a divalent radical derived from heteroalkyl (as defined above) having the specified number of carbon atoms (e.g., (C1-C8)heteroalkylene or (C1-C 10) heteroalkylene), examples are -CH2-CH2-S-CH2-CH2- and -CH2-S-CH2-CH2-NH-CH2-. In the case of heteroalkylene groups, heteroatoms can also occupy either or both of the chain termini. Furthermore, in the case of alkylene and heteroalkylene linking groups, no orientation of the linking group is implied. In selected embodiments, heteroalkylene is a heteroalkyl group, as defined above, in which two or more of the heteroalkyl group's hydrogen atoms have been replaced with bonds (i.e., the heteroalkylene can be trivalent). In some aspects, the heteroalkyl or heteroalkylene can be saturated. In some aspects, the heteroalkylene is unsubstituted. Optionally, the heteroalkylene can be substituted, for example, with one or more groups.

[0097] The term "halogen", unless otherwise specified, generally refers to elements of main group 7, preferably fluorine, chlorine, bromine and iodine, more preferably fluorine, chlorine and bromine, even more preferably fluorine and chlorine.

[0098] Terms such as "substituted," "optionally substituted," or "optionally substituted," unless otherwise specified, generally mean that one or more hydrogen atoms can each be independently replaced with a substituent. Exemplary substituents include -X, -R, -O, -C, -C, -D, -E, -F, -H, -F, -I ... - , -OR, -SR, -S - , -NR2, -NR3, =NR, -CX3, -CN, -OCN, -SCN, -N=C=O, -NCS, -NO, -NO2, =N2, -N3, -NRC(=O)R, -C(=O)R, -C(=O)NR2, -SO3 - , -SO3H, -S(=O)2R, -OS(=O)2OR, -S(=O)2NR, -S(=O)R, -OP(=O)(OR) 2、 -P(=O)(OR)2, -PO4 3-, -PO3H2, -C(=O)R, -C(=O)X, -C(=S)R, -COR, -CO2, -C(=S)OR, -C(=O)SR, -C(=S)SR, -C(=O)NR2, -C(=S)NR2, or -C(=NR)NR2, where each X is independently a halogen: -F, -Cl, -Br, or -I; and each R is independently -H, -(C1-C 20 ) alkyl (e.g., -(C1-C 10 ) alkyl or -(C1-C8) alkyl), -(C6-C 20 ) aryl (e.g., -(C6-C 10 )aryl or preferably -C6-aryl), -(C3-C 14 ) heterocycle (e.g., -(C 10 )heterocycle or -(C3-C8)heterocycle), a protecting group, or a prodrug moiety. Typical substituents also include (=O).

[0099] The term "aliphatic or aromatic residue," as used herein, generally refers to an aliphatic substituent, such as, but not limited to, an alkyl residue, which may optionally be substituted with further aliphatic and / or aromatic substituents. As a non-limiting example, an aliphatic residue may be a direct link (R 1 In the case of , for example, the linkage to the oxygen atom attached to phosphorus) is aliphatic, so long as the linkage can be a nucleic acid, an enzyme, a coenzyme, a nucleotide, an oligonucleotide, a monosaccharide, a polysaccharide, a polymer, a fluorophore, an optionally substituted benzene, etc. An aromatic residue is a substituent in which the direct linkage to the core structure is part of an aromatic system, for example, an optionally substituted phenyl or triazolyl or pyridyl, or a nucleotide, as a non-limiting example, the direct linkage of the nucleotide to the core structure is via, for example, a phenyl residue. The term "aromatic residue" as used herein also includes heteroaromatic residues.

[0100] The term "peptide," unless otherwise specified, generally refers to an organic compound containing two or more amino acids covalently linked by peptide bonds (amide bonds). Peptides may be referred to based on the number of constituent amino acids, i.e., a dipeptide contains two amino acid residues, a tripeptide contains three amino acids, etc. Peptides containing 30 or fewer amino acids may be referred to as oligopeptides, while those containing, for example, more than 30 amino acid residues may be referred to as "polypeptides." Amino acids and peptides according to the present disclosure may also be modified with functional groups. Non-limiting examples are sugars, such as N-acetylgalactosamine (GalNAc), or protecting groups, such as fluorenylmethoxycarbonyl (Fmoc) modifications or esters.

[0101] pharmaceutically acceptable salts The present disclosure also relates to "pharmaceutically acceptable salts." Any pharmaceutically acceptable salt may be used. In particular, the term "pharmaceutically acceptable salts" refers to salts of the conjugates or compounds of the present invention that are pharmaceutically acceptable and possess the desired pharmacological activity of the parent compound. In particular, such salts have low toxicity and may be inorganic or organic acid addition salts and base addition salts. Specifically, such salts include, but are not limited to: (1) salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and phosphoric acid, or with acetic acid, propionic acid, hexanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphor acid, or (2) salts formed when an acidic proton present in the parent compound is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion, or an aluminum ion, or when coordinated with an organic base, e.g., ethanolamine, diethanolamine, triethanolamine, and N-methylglucamine. Salts further include, by way of example only, sodium, potassium, calcium, magnesium, ammonium, and tetraalkylammonium; and when the compound contains a basic functional group, salts of non-toxic organic or inorganic acids, e.g., hydrochloride, hydrobromide, tartrate, mesylate, acetate, maleate, and oxalate, are included. For quaternary amines, counterions or anionic counterions may be used to maintain electronic neutrality.Exemplary counterions include halide ions (e.g., F). - , Cl - , Br - , I - ), NO3 - , ClO4 - , O.H. - , H2PO4 - , HSO4 - , sulfonate ions (e.g., methanesulfonate, trifluoromethanesulfonate, p-toluenesulfonate, benzenesulfonate, 10-camphorsulfonate, naphthalene-2-sulfonate, and naphthalene-1-sulfonic acid-5-sulfonate, etc.), and carboxylate ions (e.g., acetate, ethanoate, propanoate, benzoate, glycerate, lactate, tartrate, and glycolate, etc.).

[0102] solvate As used herein, the term "solvate" may refer to an aggregate containing one or more molecules of a conjugate or compound described herein and one or more molecules of a solvent. The solvent may be water, in which case the solvate may be a hydrate. Alternatively, the solvent may be an organic solvent. Thus, the conjugate or compound of the present disclosure may exist as a hydrate, including a monohydrate, a dihydrate, a hemihydrate, a sesquihydrate, a trihydrate, a tetrahydrate, and the like, as well as corresponding solvated forms. The compounds of the present invention may be true solvates, but in other cases, the compounds of the present invention may only retain incidental water or may be a mixture of water and some incidental solvent.

[0103] In some aspects / embodiments, the present invention relates to an anti-NaPi2b antibody (e.g., an antibody against NPT2B_human sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: O95436 or SEQ ID NO: 1) and / or an antibody against NPT2B_rat sodium-dependent phosphate transport protein 2B (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2)), wherein (a) the NaPi2b antibody is capable of binding to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), and preferably, the binding to the human Napi2b and the rat Napi2b has approximately the same K D and more preferably, the antibody is selected from the group consisting of AV-25 antibody, AV-15 antibody, AV-18 antibody, AV-21 antibody, and AV-29 antibody, and most preferably, the antibody has approximately the same K D have a difference of up to 50% (e.g., a difference of up to 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 7%, 5%, 4%, 3%, 2%, or 1%); (b) the NaPi2b antibody is capable of cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2); (c) the NaPi2b antibody is capable of cross-reactivity with cynomolgus monkey (e.g., Macaca fascicularis) Napi2b (e.g., having UniProtKB Accession No.: A0A2K5UHY1 or SEQ ID NO: 3); (d) the NaPi2b antibody is capable of internalization, preferably by antigen-mediated antibody internalization; (e) the NaPi2b antibody optionally comprises a heavy chain variable region (V H ) may have no dipeptide deamidation site within CDR2, and preferably, the absent dipeptide deamidation site is V H It is NG (Asn-Gly) in CDR2.

[0104] In some aspects / embodiments, the present invention relates to monoclonal human or humanized IgG1 anti-NaPi2b antibodies, preferably comprising a kappa (κ) light chain.

[0105] In some aspects / embodiments, the present invention relates to hybridomas that produce the antibodies of the present invention.

[0106] In some aspects / embodiments, the present invention relates to nucleic acids encoding the antibodies of the present invention.

[0107] In some aspects / embodiments, the present invention relates to an expression vector comprising at least one of the nucleic acid molecules of the present invention.

[0108] The present invention further relates to: In some aspects / embodiments, the present invention relates to an isolated host cell (e.g., an isolated recombinant host cell) comprising the vector and / or nucleic acid of the present invention.

[0109] In some aspects / embodiments, the present invention relates to antibody drug conjugates (ADCs) comprising the anti-NaPi2b antibodies of the present invention.

[0110] In some aspects / embodiments, the present invention relates to an antibody drug conjugate (ADC) of the invention comprising an anti-NaPi2b antibody of the invention (e.g., a humanized monoclonal NaPi2b-specific IgG1 antibody) conjugated to a cytotoxic payload, wherein (a) the cytotoxic payload is selected from the group consisting of camptothecin, maytansinoid, calicheamicin, duocarmycin, tubulysin, amatoxin, dolastatin, and auristatin, such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimer, indolino-benzodiazepine dimer, radioisotope, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof; and / or (b) the cytotoxic payload is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, veronika, vincristine ... and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker (L) comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, wherein the releasing unit is cleavable by a protease.

[0111] In some aspects / embodiments, the present invention provides a compound of formula (I): TIFF2025536308000002.tif34128 or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, Ab is an anti-NaPi2b antibody described herein; TIFF2025536308000003.tif5128 is a double bond or TIFF2025536308000004.tif5128 is a single bond; If TIFF2025536308000005.tif6128 is a double bond, V is absent, or TIFF2025536308000006.tif5128 is a single bond, V is H or (C1-C8) alkyl; TIFF2025536308000007.tif6128 is a double bond, X is R3-C, or If TIFF2025536308000008.tif6128 is a single bond, then X is TIFF2025536308000009.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20.

[0112] Preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H. Preferably, R 4 When present, R is H or (C1-C8) alkyl; more preferably, R 4 When present, R is H. Preferably, R 5 When present, R is H or (C1-C8) alkyl; more preferably, R 5 When present, R is H. Preferably, R 6 When present, R is H or (C1-C8) alkyl; more preferably, R 6 When present, R is H. Preferably, R 7 When present, R is H or (C1-C8) alkyl; more preferably, R 7 is H, if present.

[0113] Preferably, TIFF2025536308000010.tif5128 is a double bond; V is absent; X is R3-C; and R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl; more preferably, R 3 is H.

[0114] More preferably, TIFF2025536308000011.tif6128 represents a double bond; V is absent; X represents R-C, and R represents H or (C1-C8) alkyl. Preferably, R 3represents H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. In a preferred embodiment, R3 is H.

[0115] In some embodiments, TIFF2025536308000012.tif5128 may be a single bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000013.tif9128; R3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; more preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 4 is H or (C1-C8) alkyl, preferably R 4 is H.

[0116] In some embodiments, TIFF2025536308000014.tif6128 may represent a single bond; V may be H or (C1-C8) alkyl; X may be TIFF2025536308000015.tif9128; and R3 and R4 may independently represent H or (C1-C8) alkyl. Preferably, R3 and R4 independently represent H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. Preferably, R3 and R4 are the same; even more preferably, R 3、 R 4、and V are the same. More preferably, R3 and R4 are both H. Preferably, V is H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. Even more preferably, V is H. In a preferred embodiment, R3, R4, and V are each H.

[0117] The integer m ranges from 1 to 10. Thus, the integer m may be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Preferably, the integer m ranges from 1 to 4. More preferably, the integer m is 1 or 2. Even more preferably, the integer m is 1.

[0118] The integer n is in the range of 1 to 20. Thus, the integer n may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. Preferably, the integer n is in the range of 1 to 10. More preferably, the integer n is in the range of 2 to 10. Even more preferably, the integer n is in the range of 4 to 10. Even more preferably, the integer n is in the range of 6 to 10. Even more preferably, the integer n is 6, 7, 8, 9, or 10. Even more preferably, the integer n is in the range of 7 to 10. Even more preferably, the integer n is 7, 8, or 9. Even more preferably, the integer n is 7 or 8. Even more preferably, the integer n is 8.

[0119] The integer n is in the range of 1 to 20. Preferably, the integer n is in the range of 1 to 10. More preferably, the integer n is in the range of 2 to 8. Even more preferably, the integer n is 2, 3, 4, 5, or 6. Even more preferably, the integer n is in the range of 3 to 6. Even more preferably, the integer n is 3, 4, or 5. Even more preferably, the integer n is 4 or 5. Even more preferably, the integer n is 4.

[0120] Preferably, m is an integer in the range of 1 to 4, more preferably 1 or 2, even more preferably 1; preferably, n is an integer in the range of 1 to 20, more preferably 1 to 10, even more preferably 2 to 10, even more preferably 4 to 10, even more preferably 6 to 10, even more preferably, n is 6, 7, 8, 9, or 10, even more preferably, n is in the range of 7 to 10, even more preferably, n is 7, 8, or 9, even more preferably, n is 7 or 8, and even more preferably, n is 8.

[0121] Preferably, m is an integer in the range of 1 to 4, more preferably 1 or 2, more preferably 1; preferably, n is an integer in the range of 1 to 20, more preferably 1 to 10, even more preferably 2 to 8; even more preferably, n is 2, 3, 4, 5, or 6; even more preferably, n is in the range of 3 to 6; even more preferably, n is 3, 4, or 5; even more preferably, n is 4 or 5, and even more preferably, n is 4.

[0122] Preferably, m is 1; preferably, n is an integer in the range of 1 to 20, more preferably 1 to 10, even more preferably 2 to 10, even more preferably 4 to 10, even more preferably 6 to 10, even more preferably, n is 6, 7, 8, 9, or 10, even more preferably, n is in the range of 7 to 10, even more preferably, n is 7, 8, or 9, even more preferably, n is 7 or 8, and even more preferably, n is 8. Thus, preferably, m is 1 and n is an integer in the range of 1 to 20. More preferably, m is 1 and n is an integer in the range of 1 to 10. Even more preferably, m is 1 and n is an integer in the range of 2 to 10. Even more preferably, m is 1 and n is an integer in the range of 4 to 10. Even more preferably, m is 1 and n is an integer in the range of 6 to 10. Even more preferably, m is 1 and n is 6, 7, 8, 9, or 10. Even more preferably, m is 1 and n is an integer in the range of 7 to 10. Even more preferably, m is 1 and n is 7, 8, or 9. Even more preferably, m is 1 and n is 7 or 8. Even more preferably, m is 1 and n is 8.

[0123] Preferably, m is 1; preferably, n is an integer ranging from 1 to 20, more preferably from 1 to 10, even more preferably from 2 to 8; even more preferably, n is 2, 3, 4, 5, or 6, even more preferably, n is in the range of 3 to 6; even more preferably, n is 3, 4, or 5; even more preferably, n is 4 or 5, and even more preferably, n is 4. Thus, preferably, m is 1 and n is an integer ranging from 1 to 20. More preferably, m is 1 and n is an integer ranging from 1 to 10. Even more preferably, m is 1 and n is an integer ranging from 2 to 8. Even more preferably, m is 1 and n is 2, 3, 4, 5, or 6. Even more preferably, m is 1 and n is in the range of 3 to 6. Even more preferably, m is 1 and n is 3, 4, or 5. Even more preferably, m is 1 and n is 4 or 5. Even more preferably, m is 1 and n is 4.

[0124] In some embodiments, the number of cytotoxic moieties CM per antibody Ab may be 1 to 20. Preferably, the number of cytotoxic moieties CM per antibody Ab is 1 to 14. More preferably, the number of cytotoxic moieties CM per antibody Ab is 2 to 14. More preferably, the number of cytotoxic moieties CM per antibody Ab is 4 to 14. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 5 to 12. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 6 to 12. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 7 to 10. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 8.

[0125] In some embodiments, the number of cytotoxic moieties CM per antibody Ab may be 1 to 20. Preferably, the number of cytotoxic moieties CM per antibody Ab is 1 to 14. More preferably, the number of cytotoxic moieties CM per antibody Ab is 1 to 12. More preferably, the number of cytotoxic moieties CM per antibody Ab is 2 to 10. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 2 to 8. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 2 to 6. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 3 to 5. Even more preferably, the number of cytotoxic moieties CM per antibody Ab is 4.

[0126] Ab is an anti-NaPi2b antibody described herein. Any anti-NaPi2b antibody described herein may be used.

[0127] Base Y The group Y is NR 5 , S, O, and CR 6 R 7 R 5 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 5 is H or (C1-C8) alkyl; more preferably, R 5 is H. R 6 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 6 is H or (C1-C8) alkyl; more preferably, R 6 is H. R 7 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 7 is H or (C1-C8) alkyl, more preferably R 7 is H.

[0128] Preferably, Y is selected from the group consisting of NH, S, O, and CH. More preferably, Y is NH, S, or O. In some embodiments, Y is CH. In some embodiments, Y is O. In some embodiments, Y is S.

[0129] In a highly preferred embodiment, Y is NH.

[0130] base R 1 R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue.

[0131] R 1 may represent an optionally substituted (C1-C8) alkyl.

[0132] R 1 may represent (C1-C8)alkyl optionally substituted by at least one of F, Cl, Br, I, —NO2, —N((C1-C8)alkyl)H, —NH2, —N3, —N((C1-C8)alkyl)2, ═O, (C3-C8)cycloalkyl, —SS-((C1-C8)alkyl), (C2-C8)alkenyl, or (C2-C8)alkynyl.

[0133] R 1 may represent an optionally substituted phenyl.

[0134] R 1 may represent phenyl, optionally independently substituted with at least one of (C1-C8)alkyl, F, Cl, I, Br, —NO2, —N((C1-C8)alkyl)H, —NH2, or —N((C1-C8)alkyl)2.

[0135] R 1 may represent an optionally substituted 5- or 6-membered aromatic heterocycle, such as pyridyl.

[0136] R 1may represent (C1-C8) alkyl, (C1-C8) alkyl substituted with -SS-(C1-C8) alkyl, (C1-C8) alkyl substituted with optionally substituted phenyl, or phenyl, or phenyl substituted with -NO2.

[0137] R 1 may represent methyl, ethyl, propyl, or butyl, preferably methyl or ethyl, more preferably ethyl.

[0138] Polyethylene Glycol Units Preferably, R 1 is a polyethylene glycol unit. In some embodiments, R 1 is a polyethylene glycol unit comprising 1 to 100, preferably 2 to 50, more preferably 3 to 45, even more preferably 4 to 40, even more preferably 6 to 35, and still more preferably 8 to 30 ethylene glycol subunits, each of which has the structure: TIFF2025536308000016.tif9128. Throughout this specification, the structure: TIFF2025536308000017.tif9128 is represented as "ethylene glycol subunits".

[0139] Preferably, R 1 is a polyethylene glycol unit comprising 16 to 30, more preferably 20 to 28, even more preferably 22, 23, 24, 25, or 26, and even more preferably 23, 24, or 25 ethylene glycol subunits, each of which has the structure: TIFF2025536308000018.tif9128. In a preferred embodiment, R 1 is a polyethylene glycol unit comprising 24 or about 24 ethylene glycol subunits, each of which has the structure: I have TIFF2025536308000019.tif9128.

[0140] More preferably, R 1 The structure: TIFF2025536308000020.tif15128, During the ceremony, TIFF2025536308000021.tif10128 indicates the position of O attached to phosphorus; K F is H (hydrogen) or a capping group as described herein; preferably, K F -H (hydrogen), -PO3H, -(C1-C 10 ) alkyl, -(C1-C 10 )Alkyl-SO3H, -(C2-C 10 )Alkyl-CO2H, -(C2~C 10 ) Alkyl-OH, -(C2-C 10 ) alkyl-NH2, -(C2~C 10 ) alkyl-NH(C1-C3) alkyl, and -(C2-C 10 ) alkyl-N((C1-C3) alkyl)2; more preferably, K F is H; and o is an integer ranging from 1 to 100.

[0141] The integer o is the repeating unit in the polyethylene glycol unit. TIFF2025536308000022.tif12128 indicates the number. The integer o may be in the range of 1 to 100. Preferably, o is in the range of 2 to 50. More preferably, o is in the range of 3 to 45. Even more preferably, o is in the range of 4 to 40. Even more preferably, o is in the range of 6 to 35. Even more preferably, o is in the range of 8 to 30. In some embodiments, o is 12 or about 12. Even more preferably, o is in the range of 16 to 30. Even more preferably, o is in the range of 20 to 28. Even more preferably, o is 22, 23, 24, 25, or 26. Even more preferably, o is 23, 24, or 25. In preferred embodiments, o is 24 or about 24.

[0142] Generally, polydisperse polyethylene glycol, monodisperse polyethylene glycol, and discrete polyethylene glycol can be used in polyethylene glycol units.Polydisperse polyethylene glycol is a heterogeneous mixture of sizes and molecular weights, while monodisperse polyethylene glycol is typically purified from a heterogeneous mixture, thus providing a single chain length and molecular weight.Preferred polyethylene glycol units are discrete polyethylene glycols, i.e., compounds that are synthesized stepwise rather than through a polymerization process.Discrete polyethylene glycols provide single molecules of a defined and specified chain length.

[0143] The polyethylene glycol unit provided herein comprises one or more polyethylene glycol chains. The polyethylene glycol chains can be interconnected, for example, in a linear, branched, or star-shaped configuration. Optionally, at least one of the polyethylene glycol chains can be derivatized at one end for covalent bonding to the oxygen atom attached to phosphorus.

[0144] The polyethylene glycol unit is attached to the antibody-drug conjugate (or its intermediate) at the oxygen atom attached to the phosphorus. The other end (or ends) of the polyethylene glycol unit are free and untethered and can take the form of hydrogen, methoxy, carboxylic acid, alcohol, or other suitable functional group, such as any of the capping groups described herein. The methoxy, carboxylic acid, alcohol, or other suitable functional group serves as a cap for the terminal polyethylene glycol subunit of the polyethylene glycol unit. By "untethered," we mean that the polyethylene glycol unit is not attached at its untethered site to a cytotoxic moiety (CM), a receptor binding site, or a component of a connector unit (CU) connecting a cytotoxic moiety and / or an antibody (Ab). In embodiments where the polyethylene glycol unit comprises multiple polyethylene glycol chains, the multiple polyethylene glycol chains can be the same or different chemical moieties (e.g., polyethylene glycols with different molecular weights or numbers of subunits). These multiple polyethylene glycol chains are attached to the oxygen atom attached to the phosphorus at a single attachment site. Those skilled in the art will understand that a polyethylene glycol unit, in addition to comprising repeating polyethylene glycol subunits, may also comprise a non-polyethylene glycol substance (e.g., to facilitate interconnection of multiple polyethylene glycol chains or to facilitate linkage to the oxygen atom attached to the phosphorus). By non-polyethylene glycol substance is meant an atom in the polyethylene glycol unit that is not part of the repeating -CHCHO- subunit. In embodiments provided herein, the polyethylene glycol unit can comprise two monomeric polyethylene glycol chains interconnected via a non-polyethylene glycol element. In other embodiments provided herein, the polyethylene glycol unit can comprise two linear polyethylene glycol chains attached to a central core that is attached to the oxygen atom attached to the phosphorus (i.e., the polyethylene glycol unit is branched).

[0145] There are several polyethylene glycol conjugation methods available to those skilled in the art [e.g., EP 0 401 384 (linking PEG to G-CSF); U.S. Pat. No. 5,757,078 (PEGylation of EPO peptides); U.S. Pat. No. 5,672,662 (polyethylene glycol and related polymers mono substituted with propionic or butanoic acids and functional derivatives thereof for biotechnical applications); U.S. Pat. No. 6,077,939 (PEGylation of the N-terminal alpha carbon of peptides); and Veronese (2001) Biomaterials 22:405-417 (review on PEGylation of peptides and proteins)].

[0146] In preferred embodiments, the polyethylene glycol unit is bonded directly to the oxygen atom bonded to the phosphorus. In these embodiments, the polyethylene glycol unit does not contain a functional group for bonding to the oxygen atom bonded to the phosphorus, i.e., the oxygen atom is bonded directly to a carbon atom of the polyethylene glycol unit, preferably to the CH2 of the polyethylene glycol unit.

[0147] In one group of embodiments, the polyethylene glycol unit comprises at least 1 ethylene glycol subunit, preferably at least 2 ethylene glycol subunits, more preferably at least 3 ethylene glycol subunits, even more preferably at least 4 ethylene glycol subunits, even more preferably at least 6 ethylene glycol subunits, and even more preferably at least 8 ethylene glycol subunits. In some such embodiments, the polyethylene glycol unit comprises no more than about 100 ethylene glycol subunits, preferably no more than about 50 ethylene glycol subunits, more preferably no more than about 45 ethylene glycol subunits, more preferably no more than about 40 ethylene glycol subunits, more preferably no more than about 35 ethylene glycol subunits, and even more preferably no more than about 30 ethylene glycol subunits.

[0148] In one group of embodiments, the polyethylene glycol units comprise one or more linear polyethylene glycol chains, each having at least one ethylene glycol subunit, preferably at least two ethylene glycol subunits, more preferably at least three ethylene glycol subunits, even more preferably at least four ethylene glycol subunits, even more preferably at least six ethylene glycol subunits, and even more preferably at least eight ethylene glycol subunits. In preferred embodiments, the polyethylene glycol units comprise a total of at least one ethylene glycol subunit, preferably at least two ethylene glycol subunits, more preferably at least three, even more preferably at least four, even more preferably at least six, or even more preferably at least eight ethylene glycol subunits. In some such embodiments, the polyethylene glycol units comprise a total of no more than about 100 ethylene glycol subunits, preferably no more than about 50 ethylene glycol subunits, more preferably no more than about 45 ethylene glycol subunits, even more preferably no more than about 40 ethylene glycol subunits, even more preferably no more than about 35 ethylene glycol subunits, and even more preferably no more than about 30 ethylene glycol subunits.

[0149] In another group of embodiments, the polyethylene glycol units comprise a total of 1 to 100, preferably 2 to 50, more preferably 3 to 45, even more preferably 4 to 40, even more preferably 6 to 35, and even more preferably 8 to 30 ethylene glycol subunits. In any one of these embodiments, the ethylene glycol subunits may be any ethylene glycol subunit described herein.

[0150] In another group of embodiments, the polyethylene glycol units comprise one or more linear polyethylene glycol chains having a total of 1 to 100, preferably 2 to 50, more preferably 3 to 45, even more preferably 4 to 40, even more preferably 6 to 35, and even more preferably 8 to 30 ethylene glycol subunits.

[0151] In another group of embodiments, the polyethylene glycol unit is a linear single polyethylene glycol chain having at least 1 ethylene glycol subunit, preferably at least 2 ethylene glycol subunits, more preferably at least 3 ethylene glycol subunits, even more preferably at least 6 ethylene glycol subunits, and even more preferably at least 8 ethylene glycol subunits. Optionally, in any one of these embodiments, the linear single polyalkylene glycol chain may be derivatized.

[0152] In another group of embodiments, the polyethylene glycol unit is a linear single polyethylene glycol chain having 1 to 100, preferably 2 to 50, more preferably 3 to 45, more preferably 4 to 40, more preferably 6 to 35, more preferably 8 to 30 ethylene glycol subunits. Optionally, in any one of these embodiments, the linear single polyethylene glycol chain may be derivatized.

[0153] In any one of the embodiments provided herein, R 1 An exemplary linear polyethylene glycol unit that can be used is: TIFF2025536308000023.tif40128In the formula, the wavy line indicates the binding site to the oxygen atom attached to phosphorus; R 20 is a PEG linking unit; preferably, R 20 does not exist; R 21 is a PEG capping unit (referred to herein as R21 is "K F ") and; R 22 is a PEG linking unit (i.e., for connecting multiple PEG subunit chains together); n is independently selected from 1 to 100, preferably 2 to 50, more preferably 3 to 45, more preferably 4 to 40, even more preferably 6 to 35, and even more preferably 8 to 30; e is 2 to 5; Each n' is independently selected from 1 to 100, preferably 2 to 50, more preferably 3 to 45, more preferably 4 to 40, even more preferably 6 to 35, and even more preferably 8 to 30. In preferred embodiments, there are at least 1, preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 6, and even more preferably at least 8 ethylene glycol subunits in the polyethylene glycol unit. In some embodiments, there are 100 or fewer, preferably 50 or fewer, more preferably 45 or fewer, more preferably 40 or fewer, more preferably 35 or fewer, and even more preferably about 30 or fewer ethylene glycol subunits in the polyethylene glycol unit. R 20 When is not present, the (CH2CH2O) subunit is directly attached to the oxygen atom attached to the phosphorus.

[0154] Preferably, the linear polyethylene glycol unit is TIFF2025536308000024.tif9128, where the wavy line indicates the site of attachment to the oxygen atom attached to phosphorus; R 20 , R 21 (In this specification, "K F ") and n are as defined herein; more preferably, R 20 is absent. In a preferred embodiment, n is 12 or about 12. In a preferred embodiment, n is 24 or about 24. Preferably, R 21 is H.

[0155] Polyethylene glycol linking unit R 20 When present, is part of a polyethylene glycol unit and serves to link the polyethylene glycol unit to the oxygen atom attached to the phosphorus. In this regard, the oxygen atom attached to the phosphorus forms a bond with the polyethylene glycol unit. In an exemplary embodiment, the PEG linking unit R 20 If exists, * -(C1~C 10 ) Alkyl- # , * -Arylene- # , * -(C1~C 10 )Alkyl-O- # , * -(C1~C 10 )Alkyl-C(O)- # , * -(C1~C 10 )Alkyl-C(O)O- # , * -(C1~C 10 )Alkyl-NH- # , * -(C1~C 10 )Alkyl-S- # , * -(C1~C 10 )Alkyl-C(O)-NH- # , * -(C1~C 10 )Alkyl-NH-C(O)- # , and * -CH2-CH2SO2-(C1~C 10 ) Alkyl- # wherein: * indicates the point of attachment to the oxygen attached to the phosphorus, and # indicates the point of attachment to the ethylene glycol unit.

[0156] PEG Consolidation Unit R 22 When present, is a non-PEG material that is part of a polyethylene glycol unit and serves to link two or more chains of repeating -CHCHO- subunits. In an exemplary embodiment, the PEG linking unit R22 If exists, * -(C1~C 10 )Alkyl-C(O)-NH- # , * -(C1~C 10 )Alkyl-NH-C(O)- # , * -(C2~C 10 )Alkyl-NH- # , * -(C2~C 10 )Alkyl-O- # , * -(C1~C 10 )Alkyl-S- # ,or * -(C2~C 10 )Alkyl-NH- # are independently selected from the group consisting of: * indicates the point of attachment to the oxygen atom of an ethylene glycol subunit, and # indicates the point of attachment to a carbon atom of another ethylene glycol subunit.

[0157] R 21 The group is referred to herein as "K F ", which in exemplary embodiments may be H (hydrogen) or a capping group as described herein. Preferably, R 21 -H, -PO3H, -(C1~C 10 ) alkyl, -(C1-C 10 )Alkyl-SO3H, -(C2-C 10 )Alkyl-CO2H, -(C2~C 10 ) Alkyl-OH, -(C2-C 10 ) alkyl-NH2, -(C2~C 10 ) alkyl-NH(C1-C3) alkyl, and -(C2-C 10 In some embodiments, R 21 is -(C1~C 10 ) alkyl, especially methyl. More preferably, R 21 is H.

[0158] In any one of the embodiments provided herein, R 1 Exemplary linear polyethylene glycol units that can be used are: TIFF2025536308000025.tif56128, where the wavy line indicates the site of attachment to the oxygen atom attached to the phosphorus; each n is 1 to 100, preferably 2 to 50, more preferably 3 to 45, even more preferably 4 to 40, even more preferably 6 to 35, and even more preferably 8 to 30. In some embodiments, n is about 12. In some embodiments, n is about 24.

[0159] In some embodiments, the polyethylene glycol unit is about 300 daltons to about 5 kilodaltons, about 300 daltons to about 4 kilodaltons, about 300 daltons to about 3 kilodaltons, about 300 daltons to about 2 kilodaltons, or about 300 daltons to about 1 kilodalton. In some such aspects, the polyethylene glycol unit may have at least 6 ethylene glycol subunits or at least 8 ethylene glycol subunits. In some such aspects, the polyethylene glycol unit may have at least 6 ethylene glycol subunits or at least 8 ethylene glycol subunits, but not more than 100 ethylene glycol subunits, preferably not more than 50 ethylene glycol subunits. In some embodiments, the polyethylene glycol unit is about 300 daltons to about 5 kilodaltons, about 300 daltons to about 4 kilodaltons, about 300 daltons to about 3 kilodaltons, about 300 daltons to about 2 kilodaltons, or about 300 daltons to about 1 kilodalton. In some such aspects, the polyethylene glycol unit may have at least 6 ethylene glycol subunits or at least 8 ethylene glycol subunits, hi some aspects, the polyethylene glycol unit has at least 6 ethylene glycol subunits or at least 8 ethylene glycol subunits, but not more than 100 ethylene glycol subunits, preferably not more than 50 ethylene glycol subunits.

[0160] In some embodiments, R 1 is a polyethylene glycol unit, there are no other ethylene glycol subunits and / or alkylene glycol subunits present in the antibody drug conjugate of Formula (I) (i.e., there are no ethylene glycol subunits and / or alkylene glycol subunits present in any of the other components of the antibody drug conjugate, such as in the connector units (CU) provided herein). In other aspects, R 1is a polyethylene glycol unit, then no more than 8, no more than 7, no more than 6, no more than 5, no more than 4, no more than 3, no more than 2, or no more than 1 other ethylene glycol subunits and / or alkylene glycol subunits are present in the conjugate of Formula (I) (i.e., no more than 8, 7, 6, 5, 4, 3, 2, or 1 other ethylene glycol subunits and / or alkylene glycol subunits are present in other components of the conjugate, for example, in a connector unit (CU) provided herein).

[0161] It will be appreciated that when referring to ethylene glycol subunits and / or alkylene glycol subunits, the number of subunits can represent an average number, depending on the context, for example, when referring to a population of conjugates or intermediate compounds, and when using polydisperse polyethylene glycols.

[0162] "CU": Connector unit The present disclosure provides antibody drug conjugates (ADCs) in which an anti-NaPi2b antibody (Ab) as described herein is linked to a cytotoxic moiety (CM). According to the present disclosure, the antibody (Ab) can be linked to the cytotoxic moiety via a covalent bond via a group Y and a connector unit CU. As used herein, a "connector unit" CU is any chemical moiety that can link a group Y, e.g., NH, to another moiety, e.g., a cytotoxic moiety. In particular, the connector unit CU forms part of a linker (L) that can link the antibody of the present invention to one or more cytotoxic moieties CM (or drug moieties or cytotoxic payloads) as described herein. In this regard, the present invention provides a method for producing an antibody drug conjugate comprising the steps of: TIFF2025536308000026.tif34128 is again referred to. Thus, the cytotoxic moiety CM can be linked to Y via the connector unit CU. In formula (I), Ab, TIFF2025536308000027.tif5128, V, X, Y, R1 , CU, CM, m, and n are as defined herein. The connector unit CU serves to connect Y with the cytotoxic moiety (CM). The connector unit CU is any chemical moiety that can link Y to the cytotoxic moiety CM. Specifically, the connector unit CU attaches Y to the cytotoxic moiety CM via a covalent bond. The connector unit is a bifunctional or multifunctional moiety that can be used to link the cytotoxic moiety CM and Y to form the antibody drug conjugate of formula (I). The terms "connector unit," "connector reagent," "linker reagent," "cross-linking reagent," "linker derived from a cross-linking reagent," and "linker" may be used interchangeably throughout this disclosure.

[0163] The connector unit CU can be susceptible to cleavage (cleavable connector unit), such as enzymatic cleavage, acid-induced cleavage, light-induced cleavage, and disulfide bond cleavage. Enzymatic cleavage preferably includes, but is not limited to, protease-induced cleavage, peptidase-induced cleavage, esterase-induced cleavage, glycosidase-induced cleavage, phosphatase-induced cleavage, and sulfatase-induced cleavage, provided that the cytotoxic moiety and / or antibody (Ab) remains active. Alternatively, the connector unit can be substantially resistant to cleavage (e.g., a stable connector unit or a non-cleavable connector unit). In some aspects, the connector unit CU can be a precharged connector unit, a hydrophilic connector unit, a PEG-based connector unit, or a dicarboxylic acid-based connector unit. Thus, in some embodiments of any one of the antibody drug conjugates disclosed herein, the connector unit (CU) is selected from the group consisting of a cleavable connector unit, a non-cleavable connector unit, a hydrophilic connector unit, a PEG-based connector unit, a pre-charged connector unit, a peptidic connector unit, and a dicarboxylic acid-based connector unit. Preferably, the connector unit CU is a cleavable connector unit. In some embodiments, the connector unit CU is a non-cleavable connector unit.

[0164] Preferably, the connector unit CU is cleavable, as described herein. In some embodiments, the CU is a connector unit susceptible to enzymatic cleavage. In some embodiments, the CU is an acid-labile connector unit, a photolabile connector unit, a peptidase-cleavable connector unit, a protease-cleavable connector unit, an esterase-cleavable connector unit, a glycosidase-cleavable connector unit, a phosphatase-cleavable connector unit, a sulfatase-cleavable connector unit, a connector unit capable of reducing a disulfide bond, a hydrophilic connector unit, a precharged connector unit, a PEG-based connector unit, or a dicarboxylic acid-based connector unit. Preferably, the connector unit CU is cleavable by a protease, a glucuronidase, a sulfatase, a phosphatase, an esterase, or by disulfide reduction. Preferably, the connector unit is a peptidase-cleavable connector unit. Other preferred connector units are cleavable by proteases.

[0165] A non-cleavable connector unit is any chemical moiety that can link (or connect) a cytotoxic moiety to Y in a stable covalent manner and does not belong to the category listed herein as a cleavable connector unit. Thus, a non-cleavable connector unit is substantially resistant to acid-induced cleavage, light-induced cleavage, peptidase-induced cleavage, protease-induced cleavage, glycosidase-induced cleavage, phosphatase-induced cleavage, esterase-induced cleavage, and disulfide bond cleavage. Furthermore, "non-cleavable" refers to the ability of the chemical bond in or the bond to the connector unit to resist cleavage induced by acid, photolabile cleaving agents, peptidases, proteases, glycosidases, phosphatases, esterases, or chemical or physiological compounds that cleave disulfide bonds, under conditions in which the cytotoxic moiety or antibody (Ab) does not lose its activity.

[0166] An acid-labile connector unit is a connector unit that is cleavable at an acidic pH. For example, certain intracellular compartments, such as endosomes and lysosomes, have an acidic pH (pH 4-5), providing suitable conditions for cleaving an acid-labile connector unit.

[0167] Some connector units can be cleaved by peptidases, i.e., they are peptidase-cleavable connector units. In this regard, certain peptides are easily cleaved inside or outside of cells. See, for example, Trout et al., 79 Proc. Natl. Acad. Sci. USA, 626-629 (1982) and Umemoto et al., 43 Int. J. Cancer, 677-684 (1989). Peptides are composed of α-amino acids and peptide bonds, which are chemically amide bonds between the carboxylate of one amino acid and the amino group of a second amino acid.

[0168] Some connector units CU can be cleaved by esterases, i.e., they are cleavable by esterases. In this regard, certain esters can be cleaved by esterases present inside or outside of cells. Esters are formed by the condensation of carboxylic acids with alcohols. Simple esters are esters produced by the reaction of simple alcohols, such as aliphatic alcohols, small cyclic alcohols, and small aromatic alcohols.

[0169] A procharged connector unit is derived from a charged cross-linking reagent that retains its charge after incorporation into an antibody drug conjugate. Examples of procharged connector units (or linkers) can be found in US 2009 / 0274713.

[0170] Preferably, the connector unit CU is cleavable as described herein. As illustrative examples, the connector unit may be cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction. Preferably, the connector unit CU is cleavable by a protease. More preferably, the connector unit is cleavable by a cathepsin, such as, in particular, cathepsin B. The connector unit may comprise a dipeptide moiety, e.g., a valine-citrulline moiety or a valine-alanine moiety, that can be cleaved by a cathepsin, such as cathepsin B. Thus, in some embodiments, the connector unit comprises a valine-citrulline moiety. In some embodiments, the connector unit comprises a valine-alanine moiety. The connector unit may comprise a cleavage site. The term "cleavage site" may refer to a chemical moiety that is recognized by an enzyme and subsequently cleaved, e.g., by hydrolysis. As an illustrative example, a cleavage site is a sequence of amino acids that is recognized by a protease or peptidase and hydrolyzed by the protease or peptidase. In some embodiments, the cleavage site is a dipeptide. In some embodiments, the cleavage site is a valine-citrulline moiety. In some embodiments, the cleavage site is a valine-alanine moiety.

[0171] Second Spacer Unit In a preferred embodiment, the connector unit (CU) comprises a second spacer unit -A- bonded to -Y-. The second spacer unit serves to connect -Y- to another portion of the connector unit, if present, or to the cytotoxic moiety (-CM). As will be readily understood by one of skill in the art, this depends on whether or not the other portion of the connector unit is present. The second spacer unit (-A-) may be any chemical group or moiety capable of connecting -Y- to another portion of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether or not the other portion of the connector unit is present. In this regard, -Y- is bonded to the second spacer unit (-A-) as described herein. The second spacer unit (-A-) may comprise or be a functional group capable of forming a bond to another portion of the connector unit, if present, or to the cytotoxic moiety (-CM). Again, this depends on whether or not the other portion of the connector unit is present. Preferably, the functional group capable of forming a bond to another moiety of the connector unit or to the cytotoxic moiety (-CM) is, for example, TIFF2025536308000028.tif11128 or a carbonyl group, represented as -C(O)-.

[0172] The second spacer unit may be any spacer known to those skilled in the art, for example, a linear or branched hydrocarbon-based moiety. The second spacer unit may also include a cyclic moiety, such as, but not limited to, an aromatic moiety. When the second spacer unit is a hydrocarbon-based moiety, the backbone of the second spacer unit may contain only carbon atoms, but may also contain heteroatoms such as oxygen (O), nitrogen (N), or sulfur (S) atoms, and / or may contain a carbonyl group (C=O). The second spacer unit may be, for example, (C1-C 20) carbon atom chain. In exemplary embodiments for hydrocarbon-based second spacer units, the spacing moiety contains 1 to about 150, 1 to about 100, 1 to about 75, 1 to about 50, or 1 to about 40, or 1 to about 30, or 1 to about 20, including 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19, main chain atoms. One of skill in the art will know how to select an appropriate second spacer unit.

[0173] In some embodiments, the second spacer unit (-A-), if present, is * -(C1~C 10 ) Alkylene-C(O)- # , * -(C3-C8)carbocyclo-C(O)- # , * -Arylene-C(O)- # , * -(C1~C 10 ) alkylene-arylene-C(O)- # , * -Arylene-(C1~C 10 ) Alkylene-C(O)- # , * -(C1~C 10 ) Alkylene-(C3-C8)carbocyclo-C(O)- # , * -(C3~C8)carbocyclo-(C1~C 10 ) Alkylene-C(O)- # , * -(C3-C8)heterocyclo-C(O)- # , * -(C1~C 10 ) alkylene-(C3-C8)heterocyclo-C(O)- # , and * -(C3-C8)heterocyclo-(C1-C 10 ) Alkylene-C(O)- # selected from the group consisting of: *indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. Preferably, the second spacer unit (-A-), if present, is * -(C3-C8)carbocyclo-C(O)- # , * -Arylene-C(O)- # , and * -(C3-C8)heterocyclo-C(O)- # selected from the group consisting of: * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not.

[0174] In other embodiments, the second spacer unit (-A-), if present, is * -(C1~C 10 ) alkylene- # , * -(C3~C8)carbocyclo- # , * -Arylene- # , * -(C1~C 10 ) alkylene-arylene- # , * -Arylene-(C1~C 10 ) alkylene- # , * -(C1~C 10 ) Alkylene-(C3-C8)carbocyclo- # , * -(C3~C8)carbocyclo-(C1~C 10 ) alkylene- # , * -(C3~C8)heterocyclo- # , * -(C1~C 10 ) alkylene-(C3-C8) heterocyclo- # , and * -(C3-C8)heterocyclo-(C1-C 10 ) alkylene- #may be selected from the group consisting of: * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. Preferably, the second spacer unit (-A-), if present, is * -(C3~C8)carbocyclo- # , * -Arylene- # , and * -(C3~C8)heterocyclo- # may be selected from the group consisting of: * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-C), depending on whether another part of the connector unit is present or not.

[0175] Preferably, the second spacer unit -A- is TIFF2025536308000029.tif26128, wherein: TIFF2025536308000030.tif20128 is a five- or six-membered carbon ring; * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present. The carbocyclic ring may be aromatic or non-aromatic. Preferably, the second spacer unit -A- is TIFF2025536308000031.tif26128, wherein: TIFF2025536308000032.tif19128 is a 5- or 6-membered heterocycle containing 1, 2, or 3 heteroatoms independently selected from the group consisting of N, O, and S; * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. The heterocycle may be aromatic or non-aromatic.

[0176] More preferably, TIFF2025536308000033.tif26128 is TIFF2025536308000034.tif28128, wherein A, B, C, and D are each independently selected from N (nitrogen) and CH; preferably, at least one of A, B, C, and D is CH; more preferably, at least two of A, B, C, and D are CH; even more preferably, at least three of A, B, C, and D are CH, and even more preferably, each of A, B, C, and D is CH; * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. Even more preferably, TIFF2025536308000035.tif26128 is TIFF2025536308000036.tif28128, wherein A, B, C, and D are each independently selected from N (nitrogen) and CH; preferably, at least one of A, B, C, and D is CH; more preferably, at least two of A, B, C, and D are CH; even more preferably, at least three of A, B, C, and D are CH, and even more preferably, each of A, B, C, and D is CH; * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. Even more preferably, TIFF2025536308000037.tif26128 is TIFF2025536308000038.tif25128, wherein A, B, C, and D are each independently selected from N (nitrogen) and CH; preferably, at least one of A, B, C, and D is CH; more preferably, at least two of A, B, C, and D are CH; even more preferably, at least three of A, B, C, and D are CH, and even more preferably, each of A, B, C, and D is CH; * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not. In a highly preferred embodiment, the second spacer unit A is TIFF2025536308000039.tif25128, wherein: * indicates the point of attachment to -Y-; # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present or not.

[0177] In other embodiments, the second spacer unit (-A-) is TIFF2025536308000040.tif19128; m and n are each independently an integer of, for example, 0 to 20, 0 to 15, 1 to 10, 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2, or 1, preferably, m is 1 and n is 1; * indicates the position of -Y-, and # indicates the point of attachment to another part of the connector unit, if present, or to the cytotoxic moiety (-CM), depending on whether another part of the connector unit is present. Such a second spacer unit is particularly preferred when it is marked with an asterisk ( * ) may be optionally substituted at the carbon adjacent thereto, for example, with one or two (C1-C8) alkyl.

[0178] Connector Unit * -A a -Ww -B b - ## In some embodiments, the connector unit CU has the formula: * -A a -W w -B b - ## wherein -A- is a second spacer unit as described herein; a is 0 or 1; each -W- is independently an amino acid; w is independently an integer ranging from 0 to 12; -B- is a first spacer unit; b is 0 or 1; * indicates the point of attachment to -Y-; ## indicates the point of attachment to the cytotoxic moiety CM. w " or - "W w -", etc., i.e., the combination of W and an associated integer w is also referred to as an "amino acid unit". Suitable second spacer units, amino acid units, and first spacer units are described, for example, in WO 2004 / 010957 A2.

[0179] structure * -A a -W w -B b - ## In the connector unit having w The second spacer unit (-A-) serves to connect -Y- to the amino acid unit. The second spacer unit (-A-) may be any second spacer unit described herein. When present, the second spacer unit (-A-) may be any chemical group or moiety capable of linking -Y- to an amino acid unit. Alternatively, the second spacer unit may link -Y- to the first spacer unit if the amino acid unit is not present. Alternatively, the second spacer unit may link -Y- to the cytotoxic moiety (-C) if neither the first spacer unit nor the amino acid unit is present. In this regard, -Y- is attached to the second spacer unit (-A-) as described herein. The second spacer unit (-A-) may be any chemical group or moiety capable of linking -Y- to an amino acid unit ... (-W).w -) and / or the first spacer unit (-B-) are present or absent, w Preferably, the amino acid unit (-W) may comprise or be a functional group capable of forming a bond to the amino acid unit (-W), to the first spacer unit (-B-), or to the cytotoxic moiety (-CM). w Functional groups capable of forming a bond to the amino acid unit (-B-), in particular to the N-terminus of the amino acid unit, or to the first spacer unit (-B-), or to the cytotoxic moiety (-CM), are, for example, TIFF2025536308000041.tif12128 or -C(O)-. The integer a associated with the second spacer unit can be 0 or 1. Preferably, the integer a is 1. Alternatively, in other embodiments, the second spacer unit is absent (a=0).

[0180] Amino acid unit (-W w The -), when present, may link the second spacer unit A to the first spacer unit B if the first spacer unit is present. Alternatively, the amino acid unit may link the second spacer unit to a cytotoxic moiety (CM) if the first spacer unit is not present. Alternatively, the amino acid unit may link Y to the first spacer unit if the second spacer unit is not present. Alternatively, the amino acid unit may link Y to a cytotoxic moiety if the first spacer unit and second spacer unit are not present.

[0181] Amino Acid Unit-W w - may be a dipeptide (w=2), tripeptide (w=3), tetrapeptide (w=4), pentapeptide (w=5), hexapeptide (w=6), heptapeptide (w=7), octapeptide (w=8), nonapeptide (w=9), decapeptide (w=10), undecapeptide (w=11), or dodecapeptide (w=12).

[0182] In some embodiments, the amino acid unit can comprise a natural amino acid. In some embodiments, the amino acid unit can comprise a non-natural amino acid.

[0183] In any one of the embodiments described herein, each amino acid of the amino acid unit may independently exist in the L-configuration or the D-configuration, except for amino acids that are not chiral, such as glycine. Preferably, in any one of the embodiments described herein, each amino acid of the amino acid unit exists in the L-configuration (i.e., the natural configuration), except for amino acids that are not chiral, such as glycine.

[0184] Preferably, when a second spacer unit (-A-) is present, the amino acid unit -W is w The N-terminus of - is attached to the second spacer unit (A), more preferably via the carbonyl group of said second spacer unit. Preferably, in any one of the embodiments described herein, the amino acid unit -W w The C-terminus of - is attached to the first spacer unit (B), if present. Alternatively, in any one of the embodiments described herein, the amino acid unit -W w The C-terminus of - may be linked to a cytotoxic moiety (-CM) if the first spacer unit is absent. w The N-terminus of - may be attached to the first spacer unit (B), if present, and the C-terminus may be attached to the second spacer unit A, if present.

[0185] In some embodiments, w may be 1 or 2. Preferably, the amino acid unit W w is a dipeptide (w=2). In a dipeptide, each amino acid independently has the formula shown in square brackets below: TIFF2025536308000042.tif28128, wherein R 19is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl, p-hydroxybenzyl, -CH2OH, -CH(OH)CH3, -CH2CH2SCH3, -CH2CONH2, -CH2COOH, -CH2CH2CONH2, -CH2CH2COOH, -(CH2)3NHC(=NH)NH2, -(CH2)3NH2, -(CH2)3NHCOCH3, -(CH2)3NHCHO, -(CH2)4NHC(=NH)NH2, -(CH2)4NH2, -(CH2)4NHCOCH3, -(CH2)4NHCHO, -(CH2)3NHCONH2, -(CH2)4NHCONH2, -CH2CH2CH(OH)CH2NH2, 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl, The file is TIFF2025536308000043.tif95145.

[0186] The amino acid unit can be enzymatically cleaved by one or more enzymes, including but not limited to, a tumor-associated protease, preferably a cathepsin, more preferably cathepsin B, to liberate the cytotoxic moiety (-CM), which, upon liberation, in one embodiment, is protonated in vivo to yield the free cytotoxic moiety (CM). Exemplary -W w The - unit is represented by formula (VII).

[0187] Therefore, -W w The unit has the formula (VII): TIFF2025536308000044.tif23128, wherein R 20 and R 21 is the following: The file is TIFF2025536308000045.tif64128.

[0188] Exemplary amino acid units include those of formula (VII), where R 20 is benzyl and R 21 is -(CH2)4NH2(Phe-Lys); R 20 is isopropyl, and R 21is -(CH2)4NH2(Val-Lys); R 20 is isopropyl, and R 21 is -(CH2)3NHCONH2(Val-Cit)).

[0189] Useful -W w The -W unit can be designed and optimized for selectivity for enzymatic cleavage by a particular enzyme, e.g., a tumor-associated protease. w The -W unit is one whose cleavage is catalyzed by cathepsin B, cathepsin C, and / or cathepsin D, or plasmin proteases ("tumor-associated proteases"). w-unit is cleaved by cathepsin B. Suitable linkers that can be cleaved by proteases are described, for example, in GM Dubowchik et al., "Cathepsin B-Labile Dipeptide Linkers for Lysosomal Release of Doxorubicin from Internalizing Immunoconjugates; Model Studies of Enzymatic Drug Release and Antigen-Specific In Vitro Anticancer Activity," Bioconjugate Chem., Vol. 13, No. 4, 2002, 855-869; SC Jeffrey et al., "Dipeptide-based highly potent doxorubicin antibody conjugate," Bioorg. Med. Chem. Lett. 16 (2006), 358-362; and MS Kung Sutherland et al., "SGN-CD33A: a novel CD33-targeting antibody-drug conjugate using a pyrrolobenzodiazepine dimer is active in models of drug-resistant AML," Blood, 22 August 2013, volume 1. 122, number 8, 1455-1463.

[0190] R 19 , R 20 , or R 21 If is other than hydrogen, R 19 , R 20 , or R 21 The carbon atom to which R is attached is chiral. 19 , R 20 , or R 21 Each carbon atom to which R is attached may independently exist in the (S) or (R) configuration. 19 , R 20 , or R 21Each carbon atom to which is attached, if chiral, exists in the (S) configuration.

[0191] In one preferred embodiment, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). In another preferred embodiment, the amino acid unit is valine-alanine (i.e., Val-Ala or VA). In another preferred embodiment, the amino acid unit is alanine-alanine (i.e., Ala-Ala or AA). In another preferred embodiment, the amino acid unit is phenylalanine-lysine (i.e., Phe-Lys or FK). Such connector units are illustrative examples of connector units that can be cleaved by a protease, such as cathepsin B.

[0192] The notation of peptides used throughout this specification follows conventional nomenclature.Therefore, the N-terminus of a peptide is written on the left side, and the C-terminus of the peptide is written on the right side.As an exemplary but non-limiting example, in the dipeptide valine-citrulline (i.e., Val-Cit or VC), valine is the N-terminus, and citrulline is the C-terminus.Preferably, in any one of the embodiments described herein, when the second spacer unit (-A-) exists, the N-terminus of peptide, for example, dipeptide (for example, Val-Cit as an exemplary and non-limiting example) is linked to the second spacer unit (-A-), more preferably via the carbonyl group of the second spacer unit, and the C-terminus of the peptide is linked to the first spacer unit (-B-) if the first spacer unit (-B-) exists, or to the camptothecin moiety (-C) if the first spacer unit (-B-) does not exist.

[0193] In yet another embodiment, the amino acid unit is N-methylvaline-citrulline. In yet another embodiment, the amino acid unit is selected from the group consisting of 5-aminovaleric acid, homophenylalanine-lysine, tetraisoquinolinecarboxylate-lysine, cyclohexylalanine-lysine, isonepecotic acid-lysine, β-alanine-lysine, and isonepecotic acid.

[0194] Preferably, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). More preferably, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC).

[0195] In some embodiments, the amino acid unit is selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). Preferably, the amino acid unit is selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). More preferably, the amino acid unit is valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ). Connector units comprising amino acid units according to these embodiments can be illustrative examples of connector units that are cleavable, in particular, by proteases, such as cathepsins (e.g., cathepsin B). Amino acid units according to these embodiments and further suitable amino acid units are disclosed, for example, in Salomon et al., "Optimizing Lysosomal Activation of Antibody-Drug Conjugates (ADCs) by Incorporation of Novel Cleavable Dipeptide Linkers", Mol. Pharmaceutics 2019, 16, 12, 4817-4825.

[0196] The first spacer unit (B), if present, is spaced from the amino acid units (W w ) may link to the cytotoxic moiety. Alternatively, the first spacer unit (B) may link the second spacer unit (A) to the cytotoxic moiety (CM) when the amino acid unit is absent. The first spacer unit may link the cytotoxic moiety to Y when both the amino acid unit and the second spacer unit are absent.

[0197] The integer b can be 0 or 1. In preferred embodiments, the integer b is 1. Alternatively, in other embodiments, the integer b is 0 and the first spacer unit is absent.

[0198] The first spacer unit (-B-) can be of two general types: self-immolative and non-self-immolative. A non-self-immolative first spacer unit is a spacer unit that is located between the amino acid units (-W) of the linker (L). w After cleavage of -), particularly enzymatic cleavage, some or all of the first spacer unit remains attached to the cytotoxic moiety (CM). Alternatively, exemplary compounds comprising a self-immolative first spacer unit can liberate the cytotoxic moiety -CM without the need for a separate hydrolysis step. In exemplary embodiments, the self-immolative first spacer unit is attached to -W via the amino nitrogen atom of the PAB group. w - is a PAB group linked to - and directly connected to -CM via a carbonate group, a carbamate group, or an ether group. Without being bound to a particular theory or mechanism, Scheme 2 shows a possible mechanism of drug release by a PAB group directly attached to the drug moiety -D via a carbamate group or a carbonate group, as adopted by Toki et al. (2002) J Org. Chem. 67:1866-1872. Herein, the drug moiety D is also referred to as the cytotoxic moiety CM. TIFF2025536308000046.tif102128In the formula, Q is -(C1-C8)alkyl, -O-(C1-C8)alkyl, -halogen, -nitro, or -cyano; m is an integer ranging from 0 to 4, preferably m is 0, 1, or 2, more preferably m is 0 or 1, and even more preferably m is 0; and p is in the range of 1 to 20.

[0199] Without being bound by any particular theory or mechanism, Scheme 3 illustrates a possible mechanism of drug release via a PAB group directly attached via an ether or amine bond to drug moiety-D, which is also referred to herein as cytotoxic moiety CM. TIFF2025536308000047.tif111128In the formula, Q is -(C1-C8)alkyl, -O-(C1-C8)alkyl, -halogen, -nitro, or -cyano; m is an integer ranging from 0 to 4, preferably m is 0, 1, or 2, more preferably m is 0 or 1, and even more preferably m is 0; and p is in the range of 1 to 20.

[0200] Other examples of self-immolative spacers include, but are not limited to, aromatic compounds that are electronically similar to the PAB group, such as 2-aminoimidazole-5-methanol derivatives (Hay et al. (1999) Bioorg. Med. Chem. Lett. 9:2237) and ortho- or para-aminobenzyl acetals. Spacers that undergo cyclization upon hydrolysis of the amide bond can be used, such as substituted and unsubstituted 4-aminobutyric acid amides (Rodrigues et al., Chemistry Biology, 1995, 2, 223), appropriately substituted bicyclo[2.2.1] and bicyclo[2.2.2] ring systems (Storm et al., J. Amer. Chem. Soc., 1972, 94, 5815), and 2-aminophenylpropionic acid amides (Amsberry et al., J. Org. Chem., 1990, 55, 5867). Elimination of amine-containing drugs substituted at the α-position of glycine (Kingsbury et al., J. Med. Chem., 1984, 27, 1447) is also an example of a self-immolative spacer useful in exemplary compounds.

[0201] In one embodiment, the first spacer unit is a branched bis(hydroxymethyl)styrene (BHMS) unit as shown in Scheme 4, which can be used to incorporate and release multiple drugs (D). Herein, the drug moiety D is also referred to as the cytotoxic moiety CM. TIFF2025536308000048.tif44128In the formula, Q is -(C1-C8)alkyl, -O-(C1-C8)alkyl, -halogen, -nitro, or -cyano; m is an integer ranging from 0 to 4, preferably m is 0, 1, or 2; more preferably m is 0 or 1; even more preferably m is 0; p is ranging from 1 to 10; n is 0 or 1; and p is ranging from 1 to 20.

[0202] In a preferred embodiment, the first spacer unit has the formula (X): Represented by TIFF2025536308000049.tif27128, wherein Q is -(C1-C8)alkyl, -O-(C1-C8)alkyl, -halogen, -nitro, or -cyano; m is an integer ranging from 0 to 4, preferably m is 0, 1, or 2; more preferably m is 0 or 1; in a highly preferred embodiment, m is 0. Preferably, in formula (X), if an amino acid unit is present, the NH group is attached to the C-terminus of the amino acid unit. Preferably, in formula (X), the C(O) group is attached to a cytotoxic moiety (CM), such as a camptothecin moiety.

[0203] In a highly preferred embodiment, the first spacer unit has the following structure: Preferably, when an amino acid unit is present, the NH group is a PAB group having the amino acid unit (-W w -), more preferably at the C-terminus of the amino acid unit. Preferably, the C(O) group is attached to a cytotoxic moiety (CM), such as a camptothecin moiety.

[0204] In some embodiments, the first spacer group (-B-) is a "self-immolative moiety" of the heterocyclic ring system of Formula I, II, or III attached to the cytotoxic moiety and comprises an amide group. This amide group initiates a reaction upon hydrolysis by an intracellular protease that ultimately cleaves the first spacer unit (-B-) from the cytotoxic moiety, thereby liberating the cytotoxic moiety from the conjugate in an active form. The connector unit is an amino acid unit (-W) adjacent to the first spacer group (-B-). w -), and the amino acid unit (-W w -) is a substrate for an intracellular enzyme, e.g., an intracellular protease, such as a cathepsin (e.g., cathepsin B), that cleaves the peptide at the amide bond shared with the first spacer group (-B-). Heterocyclic self-immolative moieties are described, for example, in WO 2019 / 236954.

[0205] In some embodiments, the first spacer unit (-B-) is selected from the group consisting of Formulas I, II, and III: a heterocyclic self-immolative group selected from TIFF2025536308000051.tif77128; In the formula, the wavy line represents the amino acid unit -W w - and indicates the site of covalent attachment to the cytotoxic moiety CM, and U is O, S, or NR 6 and Q is CR 4 or N;V 1 , V 2 , and V 3 is independently CR 4 or N, with the proviso that in the case of formulas II and III, Q, V 1 , and V 2 at least one of is N; T can be O pendant from a cytotoxic moiety (-CM); R 1 , R 2 , R 3 , and R 4 are H, F, Cl, Br, I, OH, -N(R 5 )2, -N(R 5 )3 +, -(C1-C8) alkyl halide, carboxylate, sulfate, sulfamate, sulfonate, -SO2R 5 , -S(=O)R 5 , -SR 5 , -SO2N(R 5 )2, -C(=O)R 5 , -CO2R 5 , -C(=O)N(R 5 )2, -CN, -N3, -NO2, -(C1-C8)alkoxy, -(C1-C8)halosubstituted alkyl, polyethyleneoxy, phosphonate, phosphate, -(C1-C8)alkyl, -(C1-C8)substituted alkyl, -(C2-C8)alkenyl, -(C2-C8)substituted alkenyl, -(C2-C8)alkynyl, -(C2-C8)substituted alkynyl, -(C6-C 20 )Aryl, -(C6-C 20 ) substituted aryl, -(C3-C 20 ) heterocycle, and -(C3-C 20 ) substituted heterocycles; or when taken together, R 2 and R 3 forms a carbonyl (=O) or a spirocarbocyclic ring containing 3 to 7 carbon atoms; R 5 and R 6 is H, -(C1-C8) alkyl, -(C1-C8) substituted alkyl, -(C2-C8) alkenyl, -(C2-C8) substituted alkenyl, -(C2-C8) alkynyl, -(C2-C8) substituted alkynyl, -(C6-C 20 )Aryl, -(C6-C 20 ) substituted aryl, -(C3-C 20 ) heterocycle, and -(C3-C 20 ) substituted heterocycle; wherein -(C1-C8) substituted alkyl, -(C2-C8) substituted alkenyl, -(C2-C8) substituted alkynyl, -(C6-C 20 ) substituted aryl, and -(C3-C 20 ) substituted heterocycles include F, Cl, Br, I, OH, -N(R 5 )2, -N(R 5 )3 +, -(C1-C8) alkyl halide, carboxylate, sulfate, sulfamate, sulfonate, -(C1-C8) alkylsulfonate, -(C1-C8) alkylamino, 4-dialkylaminopyridinium, -(C1-C8) alkylhydroxy, -(C1-C8) alkylthiol, -SO2R 5 , -S(=O)R 5 , -SR 5 , -SO2N(R 5 )2, -C(=O)R 5 , -CO2R 5 , -C(=O)N(R 5 )2, -CN, -N3, -NO2, -(C1-C8)alkoxy, -(C1-C8)trifluoroalkyl, -(C1-C8)alkyl, -(C3-C 12 ) carbocycle, -(C6~C 20 )Aryl, -(C3-C 20 ) independently substituted with one or more substituents selected from the group consisting of heterocycle, polyethyleneoxy, phosphonate, and phosphate.

[0206] Antibody drug conjugates (ADCs) containing a heterocyclic self-immolative moiety are stable extracellularly or in the absence of enzymes capable of cleaving the amide bond of the self-immolative moiety, but upon entry into a cell or exposure to the appropriate enzyme, the amide bond is cleaved, initiating a spontaneous self-immolative reaction that results in cleavage of the bond covalently linking the self-immolative moiety to the camptothecin moiety, thereby liberating the drug in an underivatized or pharmacologically active form.

[0207] The self-immolative moiety in the conjugate may further comprise one or more heteroatoms, which may provide enhanced solubility, improve cleavage rates, and / or reduce the aggregation tendency of the antibody drug conjugate (ADC). Thus, heterocyclic self-immolative connector unit constructs may, in some cases, result in increased efficacy, reduced toxicity, and / or desirable pharmacokinetic and / or pharmacodynamic properties.

[0208] It is understood that when the cytotoxic moiety CM is a camptothecin moiety, T in Formulas I-III can be, for example, O, since T can be derived from a tertiary hydroxyl (-OH) present in the lactone ring portion of the camptothecin moiety. It is also possible that when the cytotoxic moiety CM is a camptothecin moiety, T in Formulas I-III can be, for example, NH, since T can be derived from an amino group (-NH) of the camptothecin moiety, e.g., exatecan.

[0209] Without being limited to theory or any particular mechanism, the presence of electron-withdrawing groups on the heterocycle of Formula I, II, or III may slow down the rate of cleavage.

[0210] In one embodiment, the self-immolative moiety is a group of formula I, where Q is N and U is O or S. Such groups have nonlinear structural features that improve the solubility of the conjugate. In this context, R is sometimes H, methyl, nitro, or CF. In one embodiment, Q is N and U is O, thereby forming an oxazole ring, and R is H. In another embodiment, Q is N and U is S, thereby forming a thiazole ring, which may be substituted at R with a Me or CF group.

[0211] In another exemplary embodiment, the self-immolative moiety is 1 and V 2 is a group of formula II, wherein Q, V are independently N or CH. 1 , and V 2 are each N. In another embodiment, Q and V 1 is N and V 2 In another embodiment, Q and V are 2 is N and V 1 In another embodiment, Q and V are 1 are both CH and V 2 is N. In another embodiment, Q is N and V1 and V 2 are both CH.

[0212] In another embodiment, the self-immolative moiety is Q, V 1 , V 2 , and V 3 are each independently N or CH. In another embodiment, Q is N and V 1 , V 2 , and V 3 are each N. In another embodiment, Q, V 1 , and V 2 are CH and V, respectively. 3 is N. In another embodiment, Q, V 2 , and V 3 are CH and V, respectively. 1 is N. In another embodiment, Q, V 1 , and V 3 are CH and V, respectively. 2 is N. In another embodiment, Q and V 2 are both N and V 1 and V 3 In another embodiment, Q and V are both CH. 2 are both CH and V 1 and V 3 are both N. In another embodiment, Q and V 3 are both N and V 1 and V 2 are both CH.

[0213] Preferably, the connector unit (CU) has the formula: * -A a -W w -B b - ## wherein integer a is 1, integer b is 1, and integer w is 2, 3, or 4, more preferably integer w is 2 or 3; in a highly preferred embodiment, integer w is 2; -A-, each -W-, and -B- are as defined herein; *indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (CM).

[0214] Preferably, the connector unit (CU) has the following structure: * -A a -W w -B b - ## and wherein -A- is a second spacer unit as described herein; a is an integer as described herein; preferably, a is 1; -B- is a first spacer unit as described herein; b is an integer as described herein; preferably, b is 1; * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM); -W w - is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Preferably, in these embodiments, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). Alternatively, in these embodiments, the amino acid unit -W w- may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). In these embodiments, the amino acid unit may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). In these embodiments, the amino acid unit may be valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ). The connector unit (CU) according to these embodiments may be an illustrative example of a connector unit that is cleavable, in particular by a protease, such as a cathepsin (eg, cathepsin B).

[0215] Preferably, the connector unit CU has the following structure: TIFF2025536308000052.tif31128, wherein -A- is a second spacer unit as described herein; a is an integer as described herein; preferably, a is 1; -W w - is an amino acid unit as described herein; w is an integer as described herein; preferably, w is 2, 3, or 4 (i.e., preferably, -W w - is a dipeptide, tripeptide, or tetrapeptide), and more preferably w is 2 or 3 (i.e., more preferably -W w - is a dipeptide or tripeptide), for example, w can be 1 or 2; in highly preferred embodiments, w is 2 (i.e., even more preferably, -W w - is a dipeptide); Q is as defined herein; m is an integer as defined herein, preferably m is 0; * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Preferably, in these embodiments, the amino acid unit -W w - is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). More preferably, in these embodiments, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). Alternatively, in these embodiments, the amino acid unit -W w- may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). In these embodiments, the amino acid unit may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). In these embodiments, the amino acid unit may be valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ). The connector unit (CU) according to these embodiments may be an illustrative example of a connector unit (CU) that is cleavable, in particular, by a protease, such as a cathepsin (eg, cathepsin B).

[0216] More preferably, the connector unit CU has the following structure: TIFF2025536308000053.tif36128, During the ceremony, TIFF2025536308000054.tif28128 is as defined herein; * indicates the point of attachment to Y; # indicates the amino acid unit -W, ​​if present w indicates the point of attachment to the - or to the NH group; -W w - is an amino acid unit as described herein; w is an integer as described herein, preferably w is 2, 3, or 4 (i.e., preferably -W w - is a dipeptide, tripeptide, or tetrapeptide), and more preferably w is 2 or 3 (i.e., more preferably -W w - is a dipeptide or tripeptide), and in highly preferred embodiments, w is 2 (i.e., even more preferably, -Ww - is a dipeptide); Q is as defined herein; m is an integer as defined herein, preferably m is 0; * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Preferably, in these embodiments, the amino acid unit -W w - is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). More preferably, in these embodiments, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). Alternatively, in these embodiments, the amino acid unit -W w- may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). In these embodiments, the amino acid unit may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). In these embodiments, the amino acid unit may be valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ). The connector unit (CU) according to these embodiments may be an illustrative example of a connector unit that is cleavable, in particular by a protease, such as a cathepsin (eg, cathepsin B).

[0217] Even more preferably, the connector unit CU has the following structure: TIFF2025536308000055.tif35128, During the ceremony, -W w - is an amino acid unit as described herein; w is an integer as described herein, preferably w is 2, 3, or 4 (i.e., preferably -W w - is a dipeptide, tripeptide, or tetrapeptide), and more preferably w is 2 or 3 (i.e., more preferably -W w - is a dipeptide or tripeptide), and in highly preferred embodiments, w is 2 (i.e., even more preferably, -W w - is a dipeptide); * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Preferably, in these embodiments, the amino acid unit -W w- is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). More preferably, in these embodiments, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). Alternatively, in these embodiments, the amino acid unit -W w - may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). In these embodiments, the amino acid unit may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). In these embodiments, the amino acid unit may be valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ). The connector unit (CU) according to these embodiments may be an illustrative example of a connector unit that is cleavable, in particular by a protease, such as a cathepsin (eg, cathepsin B).

[0218] In a preferred embodiment, the connector unit CU is w - containing the dipeptide valine-citrulline as follows: TIFF2025536308000056.tif52130, wherein * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Such connector units are illustrative examples of connector units that are cleavable, in particular by proteases, such as cathepsins (e.g., cathepsin B).

[0219] In another preferred embodiment, the connector unit CU is w - containing the dipeptide valine-alanine as follows: TIFF2025536308000057.tif38130, wherein * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Such connector units (CU) are illustrative examples of connector units that are cleavable, in particular by proteases, such as cathepsins (e.g., cathepsin B).

[0220] The connector unit CU has the following structure: TIFF2025536308000058.tif27128, During the ceremony, TIFF2025536308000059.tif26128 is as defined herein; * indicates the point of attachment to Y; # indicates the amino acid unit -W w - indicates the point of attachment to; -W w - is an amino acid unit as described herein; w is an integer as described herein, preferably w is 2, 3, or 4 (i.e., preferably -W w - is a dipeptide, tripeptide, or tetrapeptide), and more preferably, the integer w is 2 or 3 (i.e., more preferably, -W w- is a dipeptide or tripeptide), and even more preferably w is 2 (i.e., even more preferably -W w - is a dipeptide); * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM). Preferably, in these embodiments, the amino acid unit -W w - is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), alanine-alanine (i.e., Ala-Ala or AA), and phenylalanine-lysine (i.e., Phe-Lys or FK). More preferably, in these embodiments, the amino acid unit is a dipeptide selected from the group consisting of valine-citrulline (i.e., Val-Cit or VC), valine-alanine (i.e., Val-Ala or VA), and phenylalanine-lysine (i.e., Phe-Lys or FK). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC) or valine-alanine (i.e., Val-Ala or VA). Even more preferably, in these embodiments, the amino acid unit is valine-citrulline (i.e., Val-Cit or VC). Alternatively, in these embodiments, the amino acid unit -W w- may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), phenylalanine-glutamine (i.e., Phe-Gln or FQ), and threonine-threonine (i.e., Thr-Thr or TT). In these embodiments, the amino acid unit may be a dipeptide selected from the group consisting of valine-glutamine (i.e., Val-Gln or VQ), leucine-glutamine (i.e., Leu-Gln or LQ), and phenylalanine-glutamine (i.e., Phe-Gln or FQ). In these embodiments, the amino acid unit may be valine-glutamine (i.e., Val-Gln or VQ) or leucine-glutamine (i.e., Leu-Gln or LQ).

[0221] In some embodiments, the connector unit CU is w - containing the dipeptide valine-citrulline as follows: TIFF2025536308000060.tif39128, wherein * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM).

[0222] In some embodiments, the connector unit CU is w - containing the dipeptide valine-alanine as follows: TIFF2025536308000061.tif28128, wherein * indicates the point of attachment to Y; ## indicates the point of attachment to the cytotoxic moiety (-CM).

[0223] The connector unit (-CU-) has the following structure: TIFF2025536308000062.tif22128, wherein TIFF2025536308000063.tif22128 is as defined herein; *indicates the point of attachment to Y; # indicates the point of attachment to the cytotoxic moiety (-CM).

[0224] In some embodiments, the connector unit CU has the following structure: TIFF2025536308000064.tif25128, wherein * indicates the point of attachment to Y; # indicates the point of attachment to the cytotoxic moiety (-CM).

[0225] Cytotoxic moiety (-CM) The present disclosure provides antibody-drug conjugates (ADCs) comprising a cytotoxic moiety. The terms "cytotoxic moiety," "drug," "drug moiety," "payload," or "cytotoxic payload" may be used interchangeably and, as used herein, refer to a chemical or biochemical moiety conjugated to an anti-NaPi2b antibody (Ab) or its antigen-binding fragment. In this regard, reference is again made to the antibody-drug conjugates (ADCs) of formula (I) described herein. The antibody (Ab) can be conjugated to several identical or different cytotoxic moieties using any method described herein or known in the art. In some embodiments, the cytotoxic moiety can be a molecule that has a cytotoxic effect on mammalian cells, can induce apoptosis, and / or can have a regulatory effect on malignant cells. The cytotoxic moiety can be hydrophobic.

[0226] In some preferred embodiments, the cytotoxic moiety is an anti-cancer agent. Thus, the cytotoxic moiety may be selected from the group consisting of camptothecin, maytansinoid, calicheamicin, tubulysin, amatoxin, dolastatin, and auristatin such as monomethylauristatin E (MMAE) or monomethylauristatin F (MMAF), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof.

[0227] Camptothecin moiety Preferably, the cytotoxic moiety CM is a camptothecin moiety. The term "camptothecin moiety" includes camptothecin itself and analogs of camptothecin. Camptothecin is an inhibitor of topoisomerase and was discovered in 1966 by ME Wall and MC Wani in a systematic screening of natural products for anticancer drugs. Camptothecin was isolated from the bark and stem of Camptotheca acuminata (Camptotheca, Joy Tree), a tree native to China that is used as a cancer treatment in traditional Chinese medicine. Camptothecin has the following structure: I have TIFF2025536308000065.tif25128.

[0228] The term "camptothecin moiety" also includes analogs of camptothecin. In this regard, the term "camptothecin moiety" refers to the structure of camptothecin: TIFF2025536308000066.tif25128, and optionally substituted. Optional substituents include, but are not limited to, (C1-C 10The camptothecin moiety may include a (C-C) alkyl, a (C-C) carbocyclo, a (C-C) heterocyclo, an aryl, an amino group, a hydroxy group, a carbonyl group, an amide group, an ester group, a carbamate group, a carbonate group, and / or a silyl group. The camptothecin moiety may have one or more functional groups capable of forming a bond with the linker L. One of ordinary skill in the art would readily select an appropriate camptothecin moiety having the desired biological activity. Camptothecin analogs, such as topotecan, irinotecan, or belotecan, have been approved and are currently used in cancer chemotherapy.

[0229] The following camptothecin analogs are also contemplated by the term camptothecin moiety: TIFF2025536308000067.tif140164TIFF2025536308000068.tif113164Further camptothecin analogues that can be used as the camptothecin moiety are described in WO 2019 / 236954 and EP 0 495 432.

[0230] In some embodiments, the camptothecin moiety (CM) is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, siratecan, cositecan, and gimatecan. Preferably, the camptothecin moiety is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, and belotecan. SN38 has the following structure: TIFF2025536308000069.tif22128, and the structures of exatecan, camptothecin, topotecan, irinotecan, and belotecan are as set forth herein.

[0231] More preferably, in any one of the embodiments described herein, the camptothecin moiety CM has the following structure: Exatecan with TIFF2025536308000070.tif55128.

[0232] Even more preferably, the camptothecin moiety (CM) has the following structure: Exatecan with TIFF2025536308000071.tif55128.

[0233] Preferably, in any one of these embodiments, exatecan is attached to the connector unit CU via an amino group (i.e., via the NH group of exatecan). When exatecan is attached to the connector unit CU via an amino group, the hydrogen atom of the amino group of exatecan is replaced by the connector unit CU. Thus, exatecan attached to the connector unit CU via an amino group may be, for example, TIFF2025536308000072.tif59156, where # indicates the point of attachment to the connector unit CU.

[0234] In some aspects / embodiments, the present invention also provides a compound of formula (I): TIFF2025536308000073.tif34128 or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, Ab is an anti-NaPi2b antibody described herein; TIFF2025536308000074.tif5128 is a double bond or TIFF2025536308000075.tif5128 is a single bond; If TIFF2025536308000076.tif5128 is a double bond, V is absent, or TIFF2025536308000077.tif5128 is a single bond, V is H; X is R3-C when TIFF2025536308000078.tif5128 is a double bond, or If TIFF2025536308000079.tif5128 is a single bond, then X is TIFF2025536308000080.tif9128; Y is NH; R 1 The structure: TIFF2025536308000081.tif15128, During the ceremony, TIFF2025536308000082.tif9128 indicates the position of O. K F is as defined herein, preferably K F is H, and o is an integer as defined herein, preferably o is an integer in the range of 8 to 30, more preferably 16 to 30, even more preferably 20 to 28, even more preferably o is 22, 23, 24, 25, or 26, even more preferably o is 23, 24, or 25, and even more preferably o is 24; R 3 is H; R 4 is H; CU has the following structure: TIFF2025536308000083.tif50128, where # indicates the point of attachment to Y; * indicates the point of attachment to the camptothecin moiety (CM); CM is the camptothecin moiety; m is 1; and n is an integer as defined herein; Preferably, n is an integer ranging from 1 to 10, more preferably from 2 to 10, even more preferably from 4 to 10, even more preferably from 6 to 10, even more preferably from 7 to 10, and even more preferably, n is 8; or Preferably, n is an integer ranging from 1 to 10, more preferably from 2 to 8, even more preferably from 3 to 6; even more preferably, n is 4 or 5, and even more preferably, n is 4.

[0235] Preferably, TIFF2025536308000084.tif6128 is a double bond; V is absent; X is R3-C; and R 3 is H.

[0236] In some embodiments, TIFF2025536308000085.tif6128 can be a single bond; V can be H; X can be TIFF2025536308000086.tif9128;R 3 can be H; and R 4 can be H.

[0237] Preferably, the camptothecin moiety CM has the following structure: and exatecan with TIFF2025536308000087.tif55128.

[0238] More preferably, the camptothecin moiety has the following structure: Exatecan with TIFF2025536308000088.tif55128.

[0239] Preferably, in any one of these embodiments, exatecan is attached to the connector unit CU via the amino group.

[0240] In some aspects / embodiments, the present invention also provides a compound of formula (Ia): TIFF2025536308000089.tif74151, During the ceremony, Ab is an anti-NaPi2b antibody described herein; and n is an integer a as defined herein: Preferably, n is an integer ranging from 1 to 10, more preferably from 2 to 10, even more preferably from 4 to 10, even more preferably from 6 to 10, even more preferably from 7 to 10, and even more preferably, n is 8; or Preferably, n is an integer ranging from 1 to 10, more preferably from 2 to 8, even more preferably from 3 to 6; even more preferably, n is 4 or 5, and even more preferably, n is 4.

[0241] Auristatin In some embodiments, the cytotoxic moiety CM is an auristatin. Preferably, the auristatin is monomethyl auristatin F (MMAF) or monomethyl auristatin E (MMAE). More preferably, the auristatin is monomethyl auristatin E (MMAE).

[0242] In some embodiments, the cytotoxic moiety CM is monomethyl auristatin F (also known as MMAF). MMAF has the following structural formula: Represented by TIFF2025536308000090.tif34128.

[0243] Preferably, the MMAF is marked with an asterisk (" * "). Thus, when MMAF is bound to the connector unit CU through its N-terminus, the hydrogen atom at the N-terminus of MMAF is replaced by the connector unit CU.

[0244] In some embodiments, the auristatin drug moiety is monomethyl auristatin E (also known as MMAE). MMAE has the following structural formula: Represented by TIFF2025536308000091.tif38128.

[0245] Preferably, MMAE is indicated by an asterisk (" * "). Thus, when MMAE is attached to a connector unit CU via its N-terminus, a hydrogen atom at the N-terminus of MMAE is replaced by the connector unit CU.

[0246] These molecules have been shown to non-competitively inhibit the binding of vincristine to tubulin (at locations known as vinca / peptide regions), but bind to the RZX / MAY region.

[0247] Compound of formula (II) In some aspects / embodiments, the present invention also provides a compound of formula (II): TIFF2025536308000092.tif29128 or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, TIFF2025536308000093.tif6128 is a triple bond or TIFF2025536308000094.tif6128 is a double bond; If TIFF2025536308000095.tif6128 is a triple bond, V is absent, or TIFF2025536308000096.tif6128 is a double bond, V is H or (C1-C8) alkyl; TIFF2025536308000097.tif6128 is a triple bond, X is R3-C, or If TIFF2025536308000098.tif6128 is a double bond, then X is TIFF2025536308000099.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; and m is an integer ranging from 1 to 10.

[0248] Preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H. Preferably, R 4 When present, R is H or (C1-C8) alkyl; more preferably, R 4 When present, R is H. Preferably, R 5 When present, R is H or (C1-C8) alkyl; more preferably, R 5 When present, R is H. Preferably, R 6 When present, R is H or (C1-C8) alkyl; more preferably, R 6 When present, R is H. Preferably, R 7 When present, R is H or (C1-C8) alkyl; more preferably, R 7 is H, if present.

[0249] Preferably, TIFF2025536308000100.tif6128 is a triple bond; V is absent; X is R3-C; and R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl; more preferably, R 3 is H.

[0250] More preferably, TIFF2025536308000101.tif6128 represents a triple bond; V is absent; X represents R3-C, and R3 represents H or (C1-C8) alkyl. Preferably, R3 represents H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, and even more preferably H or (C1-C2) alkyl. Even more preferably, R3 is H.

[0251] In some embodiments, TIFF2025536308000102.tif6128 may be a double bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000103.tif9128; R3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; more preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 4 is H or (C1-C8) alkyl, preferably R 4 is H.

[0252] In some embodiments, TIFF2025536308000104.tif6128 may represent a double bond; V may be H or (C1-C8) alkyl; X may be TIFF2025536308000105.tif9128; and R3 and R4 may independently represent H or (C1-C8) alkyl. Preferably, R3 and R4 independently represent H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. Preferably, R3 and R4 are the same; even more preferably, R3, R4, and V are the same. More preferably, R3 and R4 are both H. Preferably, V is H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. Even more preferably, V is H. In a preferred embodiment, R3, R4, and V are each H.

[0253] In any one of the compounds of formula (II), any variable may be defined as described herein, specifically as for the antibody drug conjugate (ADC) of formula (I) and / or the thiol-containing molecule of formula (III). Thus, Ab, TIFF2025536308000106.tif6128, V, X, Y, R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , CU, CM, m, and n may be as defined herein. Preferably, Y is NH.

[0254] Methods for preparing antibody drug conjugates (ADCs) In some aspects / embodiments, the present invention relates to methods for synthesizing the antibody drug conjugates (ADCs) of the present invention.

[0255] In some aspects / embodiments, the present invention also relates to a method of preparing an antibody conjugate (ADC) of formula (I), said method comprising: Formula (II) TIFF2025536308000107.tif29128 (in the formula, TIFF2025536308000108.tif6128 is a triple bond or TIFF2025536308000109.tif6128 is a double bond; If TIFF2025536308000110.tif6128 is a triple bond, V is absent, or TIFF2025536308000111.tif6128 is a double bond, V is H or (C1-C8) alkyl; TIFF2025536308000112.tif6128 is a triple bond, X is R3-C, or If TIFF2025536308000113.tif6128 is a double bond, then X is TIFF2025536308000114.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; and m is an integer ranging from 1 to 10. or a pharmaceutically acceptable salt or solvate thereof, Formula (III): TIFF2025536308000115.tif13128 (wherein Ab is an anti-NaPi2b antibody described herein; and n is an integer ranging from 1 to 20) of thiol-containing molecules and reacting the compound with As a result, the compound of formula (I) TIFF2025536308000116.tif34128 (in the formula, Ab is an anti-NaPi2b antibody described herein; In the compound of formula (II) If TIFF2025536308000117.tif6128 is a triple bond, TIFF2025536308000118.tif6128 is a double bond, or In the compound of formula (II) If TIFF2025536308000119.tif6128 is a double bond, TIFF2025536308000120.tif5128 is a single bond; If TIFF2025536308000121.tif5128 is a double bond, V is absent, or TIFF2025536308000122.tif5128 is a single bond, V is H or (C1-C8) alkyl; TIFF2025536308000123.tif6128 is a double bond, X is R3-C, or If TIFF2025536308000124.tif6128 is a single bond, then X is TIFF2025536308000125.tif9128; Y is NH, S, O, or CH; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20. or a pharmaceutically acceptable salt or solvate thereof. Includes:

[0256] Preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H. Preferably, R 4 When present, R is H or (C1-C8) alkyl; more preferably, R 4 When present, R is H. Preferably, R 5 When present, R is H or (C1-C8) alkyl; more preferably, R 5 When present, R is H. Preferably, R 6 When present, R is H or (C1-C8) alkyl; more preferably, R 6 When present, R is H. Preferably, R 7 When present, R is H or (C1-C8) alkyl; more preferably, R 7 is H, if present.

[0257] Preferably, TIFF2025536308000126.tif6128 is a triple bond; V is absent; X is R3-C; and R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl; more preferably, R 3 is H; and TIFF2025536308000127.tif6128 represents a double bond.

[0258] More preferably, TIFF2025536308000128.tif6128 represents a triple bond; V is absent; X represents R3-C, where R3 represents H or (C1-C8) alkyl; and TIFF2025536308000129.tif6128 represents a double bond. Preferably, R3 represents H or (C1-C6) alkyl, more preferably H or (C1-C4) alkyl, even more preferably H or (C1-C2) alkyl. Even more preferably, R3 is H.

[0259] In some embodiments, TIFF2025536308000130.tif6128 may be a double bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000131.tif9128; R3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; and TIFF2025536308000132.tif6128 may represent a single bond; more preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 4is H or (C1-C8) alkyl, preferably R 4 is H.

[0260] In some embodiments, TIFF2025536308000133.tif6128 may represent a double bond; V may be H or (C1-C8) alkyl; X may be TIFF2025536308000134.tif9128; R3 and R4 may independently represent H or (C1-C8) alkyl; and TIFF2025536308000135.tif6128 may represent a single bond. Preferably, R3 and R4 independently represent H or C1-C6 alkyl, more preferably H or C1-C4 alkyl, even more preferably H or C1-C2 alkyl. Preferably, R3 and R4 are the same; even more preferably, R3, R4, and V are the same. More preferably, R3 and R4 are both H. Preferably, V is H or C1-C6 alkyl, more preferably H or C1-C4 alkyl, even more preferably H or C1-C2 alkyl. Even more preferably, V is H. In a preferred embodiment, R3, R4, and V are each H.

[0261] Figures used herein With respect to TIFF2025536308000136.tif8128, it should be noted that, as is generally known to those skilled in the art, each carbon atom is tetravalent. TIFF2025536308000137.tif18128, where X and V are as defined herein and an asterisk ( * ) indicates the bond to phosphorus) has the structure TIFF2025536308000138.tif23128 (wherein R3, R4, and V are as defined herein) Structure TIFF2025536308000139.tif19128, where X and V are as defined herein and an asterisk ( * ) indicates binding to phosphorus, and # indicates binding to receptor binding molecule (RBM). The structure TIFF2025536308000140.tif22128, where R, R, and V are as defined herein and H is hydrogen. The wavy bond indicates that the configuration of the double bond can be E or Z. It is also possible that the compound exists as a mixture of E and Z isomers.

[0262] If the anti-NaPi2b antibody (Ab) contains one or more disulfide bridges, the method may further comprise reducing at least one disulfide bridge of the antibody in the presence of a reducing agent to form a thiol group (SH). The resulting compound of formula (III) may then be reacted with a compound of formula (II) to obtain an antibody-drug conjugate (ADC) of formula (I). The reducing agent may be selected from the group consisting of tris(2-carboxyethyl)phosphine (TCEP), dithiothreitol (DTT), sodium dithionite, sodium thiosulfate, and sodium sulfite. Thus, the reducing agent may be dithiothreitol (DTT). The reducing agent may be sodium dithionite. The reducing agent may be sodium sulfite. Preferably, the reducing agent is tris(2-carboxyethyl)phosphine (TCEP).

[0263] Preferably, the reduction of at least one disulfide bridge involves the use of about 1 to about 3 equivalents, more preferably about 1 to about 2 equivalents, and even more preferably about 1 equivalent of a reducing agent per disulfide bridge to be reduced. In this context, it should be noted that, theoretically, one equivalent of a reducing agent, specifically a reducing agent described herein, is required to reduce one disulfide bridge to two thiol (SH) groups.

[0264] Preferably, the thiol-containing molecule of formula (III) is reacted with about 1 to about 4 equivalents, preferably about 1 to about 3 equivalents, more preferably about 1 to about 2 equivalents, and even more preferably about 1 to about 1.5 equivalents of the compound of formula (II) per thiol group (SH).

[0265] Preferably, the reaction of the compound of formula (II) with the thiol-containing molecule of formula (III) is carried out in an aqueous medium.

[0266] Preferably, the reaction of the compound of formula (II) with the thiol-containing molecule of formula (III) is carried out under neutral or slightly basic conditions. Even more preferably, the reaction is carried out at a pH of 6 to 10. Even more preferably, the reaction is carried out at a pH of 7 to 9.

[0267] In any one of the methods, any variable may be defined as described herein, specifically as with respect to an antibody drug conjugate (ADC) of formula (I) and / or a compound of formula (II). Thus, Ab, TIFF2025536308000141.tif9128, V, X, Y, R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , CU, CM, m, and n may be as defined herein. Preferably, Y is NH.

[0268] Methods for preparing compounds of formula (II) are known in the art. As an illustrative example, compounds of formula (II) in which the group Y is NH can be prepared by using techniques and conditions such as the Staudinger phosphonite reaction, for example, as described in WO 2018 / 041985 A1, which is incorporated herein by reference. Compounds of formula (II) in which Y is S or O can be prepared by using techniques and conditions such as those described in WO 2019 / 170710, which is incorporated herein by reference. Compounds of formula (II) in which Y is CR can be prepared in a similar manner to compounds of formula (II) in which Y is S or O, as described in WO 2019 / 170710. 6 R 7 Compounds of formula (II), wherein: can be prepared by substitution at the phosphorus atom, for example with a suitable organometallic compound, such as a Grignard compound or an organolithium compound. Those skilled in the art will readily select appropriate methods and conditions for preparing compounds of formula (II). The Examples section of the present disclosure also includes guidance regarding methods for preparing or obtaining compounds of formula (II) and / or antibody drug conjugates (ADCs) of formula (I).

[0269] The present invention also relates to an antibody drug conjugate of formula (I) obtainable or obtained by any of the methods for preparing an antibody drug conjugate of formula (I) described herein.

[0270] In some aspects / embodiments, the present invention relates to cancer. The cancer can be any cancer. Preferably, the cancer is a solid cancer and / or a metastatic cancer, and more preferably, the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, and fallopian tube cancer.

[0271] In some aspects / embodiments, the present invention relates to compositions or kits comprising an anti-NaPi2b, antibody drug conjugate (ADC), hybridoma, nucleic acid, expression vector, and / or host cell of the present invention.

[0272] In some aspects / embodiments, the present invention relates to methods of treatment (e.g., in a patient) and use of the antibodies, antibody drug conjugates (ADCs), nucleic acids, expression vectors, host cells, compositions, and / or kits of the invention.

[0273] In some aspects of the invention, antibodies of the invention are expressed in CHO cells as Fc-silenced (LALA-mutated) IgG1s and purified by Protein A chromatography.

[0274] The present invention further relates to the following items: 1. Anti-NaPi2b antibodies (e.g., antibodies against NPT2B_human sodium-dependent phosphate transport protein 2B (e.g., having UniProt accession number: O95436 or SEQ ID NO: 1) and / or antibodies against NPT2B_rat sodium-dependent phosphate transport protein 2B (e.g., having UniProt accession number: Q9JJ09 or SEQ ID NO: 2)): (a) the NaPi2b antibody is capable of binding to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), and preferably, the binding to the human Napi2b and the rat Napi2b has approximately the same K D and more preferably, the antibody is selected from the group consisting of AV-25 antibody, AV-15 antibody, AV-18 antibody, AV-21 antibody, and AV-29 antibody, and most preferably, the antibody has approximately the same K D have a difference of up to 50% (e.g., a difference of up to 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 7%, 5%, 4%, 3%, 2%, or 1%); (b) the NaPi2b antibody is capable of cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2), and preferably, the cross-reactivity is improved (e.g., by at least 10%) compared to the corresponding cross-reactivity of a parent antibody (e.g., comprising SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in FIG. 1 ) with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2), and more preferably, the cross-reactivity with rat Napi2b is measured using endogenous rat Napi2b, and most preferably, the endogenous Napi2b is located on the cell surface; (c) the NaPi2b antibody is capable of cross-reactivity with cynomolgus monkey (e.g., Macaca fascicularis) Napi2b (e.g., having UniProtKB Accession No.: A0A2K5UHY1 or SEQ ID NO: 3); (d) the NaPi2b antibody is capable of internalization, preferably by antigen-mediated antibody internalization, and preferably the internalization is improved (e.g., by at least 10%, e.g., 15%) compared to the corresponding internalization of a parent antibody (e.g., comprising SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in FIG. 1 ); (f) The NaPi2b antibody optionally comprises a heavy chain variable region (V H ) may have no dipeptide deamidation site within CDR2, and preferably, the absent dipeptide deamidation site is V H It is NG (Asn-Gly) in CDR2. 2. Anti-NaPi2b antibody is a heavy chain variable region (V H ) does not have a dipeptide deamidation site in CDR2, and preferably, the non-existent dipeptide deamidation site is V H NG (Asn-Gly) in CDR2, and more preferably, the absence of the deamidation site results in a corresponding V HThe anti-NaPi2b antibody of any preceding item, wherein post-translational modifications of CDR2 are reduced (thereby, e.g., improving the homogeneity of the antibody and / or simplifying the production process). 3. The anti-NaPi2b antibody of any one of the preceding items, wherein the anti-NaPi2b antibody has cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2); preferably, the cross-reactivity is improved (e.g., by at least 10%, e.g., 15%) compared to the corresponding cross-reactivity of a parent antibody (e.g., comprising SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in Figure 1) with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2), more preferably, the cross-reactivity with rat Napi2b is measured using endogenous rat Napi2b, and most preferably, the endogenous Napi2b is located on the cell surface. 4. An anti-NaPi2b antibody according to any one of the preceding items, wherein the anti-NaPi2b antibody has the ability to internalize, preferably by antigen-mediated antibody internalization; and more preferably, the internalization is improved (e.g., by at least 10%, e.g., 15%) compared to the corresponding internalization of a parent antibody (e.g., comprising SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in Figure 1). 5. The corresponding K of the parent antibody (e.g., including SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in Figure 1) D K is improved (e.g., by at least 10%, e.g., 15%) compared to D The anti-NaPi2b antibody of any one of the preceding items, which binds to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2). 6. The anti-NaPi2b antibody according to any one of the preceding items, which is capable of binding (e.g., specifically binding) to the extracellular domain of NaPi2b (e.g., comprising amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1). 7. The following features: (a) (e.g., in OVCAR-3 cells (e.g., HTB-161, ATCC) that endogenously express Napi2b) has a KD of about 0.01 to about 10 nmol / L, preferably about 1 to about 10 nmol / L, more preferably about 1 to about 7 nmol / L, and even more preferably about 1 to about 4 nmol / L relative to endogenously expressed human Napi2b. (More preferably, the KD is measured by FACS assay), Even most preferably, having a KD in the range of about 2.661 to about 6.644 nmol / L; and / or (b) optionally, having a KD in the range of about 0.01 to about 10 nmol / L relative to immobilized exogenous full-length Napi2b and / or one or more fragments thereof; (Preferably, the one or more fragments comprise at least one extracellular domain (ECD) of Napi2b (e.g., the ECD comprises amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1) and / or one or more fragments of the ECD (e.g., having a length of about 15 to about 30 amino acids); the full-length Napi2b and / or the one or more fragments thereof may or may not be fused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST); preferably, the KD is measured by an ELISA assay; the KD is preferably about 0.05 to about 0.2 nmol / L), More preferably, it has a KD in the range of about 0.071 to about 0.147 nmol / L. The anti-NaPi2b antibody of any one of the preceding items, 8. (a) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 4; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 5; preferably, the anti-NaPi2b antibody is an AV-25 antibody that comprises a light chain comprising SEQ ID NO: 6 and a heavy chain comprising SEQ ID NO: 7; (b) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 8; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 9; preferably, the anti-NaPi2b antibody is an AV-15 antibody that has a light chain comprising SEQ ID NO: 10 and a heavy chain comprising SEQ ID NO: 11; (c) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 12; and a light chain variable region having an amino acid sequence that is at least 80% identical (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) to SEQ ID NO: 13; preferably, the anti-NaPi2b antibody is an AV-18 antibody that comprises a light chain comprising SEQ ID NO: 14 and a heavy chain comprising SEQ ID NO: 15; (d) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 16; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 17; preferably, the anti-NaPi2b antibody is an AV-21 antibody that has a light chain comprising SEQ ID NO: 18 and a heavy chain comprising SEQ ID NO: 19; (e) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 20; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 21; preferably, the anti-NaPi2b antibody is an AV-29 antibody that has a light chain comprising SEQ ID NO: 22 and a heavy chain comprising SEQ ID NO: 23. The anti-NaPi2b antibody according to any one of the preceding items. 9. (a) an antibody comprising a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 25, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 26, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 27, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 28, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 29; (b) an antibody comprising a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 31, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 32, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 33, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 34, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 35; (c) an antibody comprising a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 36, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 37, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 38, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 39, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 40, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 41; (d) an antibody comprising a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 42, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 43, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 44, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 45, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 46, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 47; (e) an antibody comprising: a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 48, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 49, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 50; and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 51, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 52, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 53. The anti-NaPi2b antibody of any one of the preceding items, 10. The following features: (a) Monoclonal antibodies; (b) chimeric and / or humanized antibodies; (c) specific recognition of Napi2b, which is overexpressed in cancer cells; (d) a human IgG antibody, preferably a human IgG1 antibody; (e) containing kappa (κ) light chains; (f) containing lambda (λ) light chains; (g) containing an Fc-silencing mutation, such as a leucine (L) to alanine (A) substitution at positions 234 and 235 (LALA mutation); (wherein the LALA mutation can reduce the effector function of immune cells); (h) capable of being internalized by target cells (e.g., cancer cells) that express Napi2b (Preferably, the internalized antibody is directed to the lysosome); (i) Tumor-selective antibodies (preferably, the tumor is a liquid tumor and / or a solid tumor); (j) malignant cell-selective antibodies; (k) binding to human Napi2b and / or rat Napi2b in a glycosylation-dependent manner (wherein the antibody binds to a glycosylated form of the Napi2b protein); (l) (e.g., in OVCAR-3 cells (e.g., HTB-161, ATCC) that endogenously express Napi2b) a K of about 0.01 to about 10 nmol / L, preferably about 1 to about 10 nmol / L, more preferably about 1 to about 7 nmol / L, and even more preferably about 1 to about 4 nmol / L, relative to endogenously expressed human Napi2b D Having (More preferably, the K D is measured by FACS assay), Even most preferably, the K ranges from about 2.661 to about 6.644 nmol / L. D having; (m) optionally, a K in the range of about 0.01 to about 10 nmol / L for immobilized exogenous full-length Napi2b and / or one or more fragments thereof; D Having (Preferably, the one or more fragments comprise at least one extracellular domain (ECD) of the Napi2b (e.g., the ECD comprises amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1) and / or one or more fragments of the ECD (e.g., having a length of about 15 to about 30 amino acids), wherein the full-length Napi2b and / or the one or more fragments thereof are fused or unfused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST); preferably, the K D is measured by ELISA assay and is preferably about 0.05 to about 0.2 nmol / L), More preferably, the K ranges from about 0.071 to about 0.147 nmol / L. D Having The anti-NaPi2b antibody of any one of the preceding items, 11. The anti-NaPi2b antibody of any one of the preceding items, which is a monoclonal antibody. 12. The anti-NaPi2b antibody of any preceding item, which is a chimeric and / or humanized antibody. 13. An anti-NaPi2b antibody according to any one of the preceding items, which is capable of specifically recognizing Napi2b that is overexpressed in cancer cells. 14. The anti-NaPi2b antibody of any one of the preceding items, which is a human IgG antibody, preferably a human IgG1 antibody. 15. The anti-NaPi2b antibody of any one of the preceding items, which comprises a kappa (κ) light chain. 16. The anti-NaPi2b antibody of any one of the preceding items, which comprises a lambda (λ) light chain. 17. The anti-NaPi2b antibody comprises an Fc-silencing mutation (e.g., in the Fc region of the antibody), such as a leucine (L) to alanine (A) substitution at positions 234 and 235 (LALA mutation); the LALA mutation can reduce an effector function of an immune cell (e.g., the antibody comprises a mutated Fc region (or crystallizable fragment region) (e.g., according to any one of the preceding items), e.g., a tail region of the antibody that, when unmutated, interacts with a cell-surface Fc receptor (e.g., where the Fc region of an immunoglobulin molecule is composed of the constant region of a heavy chain, e.g., which, when unmutated, can bind to an antibody receptor (Fc receptor) on a cell and the C1q component of complement)); The anti-NaPi2b antibody according to any one of the preceding items. 18. The anti-NaPi2b antibody of any one of the preceding items, wherein the anti-NaPi2b antibody is capable of being internalized by target cells (e.g., cancer cells) that express Napi2b; preferably, the internalized antibody is targeted to lysosomes. 19. The anti-NaPi2b antibody according to any one of the preceding items, wherein the anti-NaPi2b antibody is a tumor-selective antibody, and preferably the tumor is a liquid tumor and / or a solid tumor. 20. The anti-NaPi2b antibody of any one of the preceding items, which is a malignant cell-selective antibody. 21. The anti-NaPi2b antibody according to any preceding item, which is capable of binding to human Napi2b and / or rat Napi2b in a glycosylation-dependent manner and binds to glycosylated forms of Napi2b proteins. 22. The anti-NaPi2b antibody has a K of about 0.01 to about 10 nmol / L, preferably about 1 to about 10 nmol / L, more preferably about 1 to about 7 nmol / L, and even more preferably about 1 to about 4 nmol / L, relative to endogenously expressed human Napi2b (e.g., in OVCAR-3 cells (e.g., HTB-161, ATCC) that endogenously express Napi2b). D and more preferably, D is measured by FACS assay, and most preferably in the range of about 2.661 to about 6.644 nmol / L. D 4. The anti-NaPi2b antibody of any one of the preceding items, comprising: 23. The anti-NaPi2b antibody has a K in the range of about 0.01 to about 10 nmol / L for immobilized exogenous full-length Napi2b and / or one or more fragments thereof. D and preferably, the one or more fragments comprise at least one extracellular domain (ECD) of the Napi2b (e.g., the ECD comprises amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1) and / or one or more fragments of the ECD (e.g., having a length of about 15 to about 30 amino acids), and the full-length Napi2b and / or the one or more fragments thereof are fused or unfused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST), and preferably, the K D is measured by ELISA assay, and is preferably in the range of about 0.05 to about 0.2 nmol / L, more preferably about 0.071 to about 0.147 nmol / L. D having The anti-NaPi2b antibody according to any one of the preceding items. 24. The anti-NaPi2b antibody of any preceding item, wherein the antibody is conjugated to a labeling group. 25. The anti-NaPi2b antibody of any one of the preceding items, wherein the antibody is obtainable using a hybridoma (e.g., the antibody is a recombinant antibody). 26. An anti-NaPi2b antibody according to any one of the preceding items, obtained according to Example 1, 2 or 3 herein and / or having the characteristics described in Example 1, 2 or 3 herein (e.g., Figures 1 to 50, in particular Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 19, and / or Figure 20). 27. An anti-NaPi2b antibody according to any one of the preceding items, comprising one or more (e.g., two) CDRs, heavy chain variable regions, light chain variable regions, heavy chains, light chains, and / or signal sequences of any one of the preceding items, preferably selected from the group consisting of SEQ ID NOs: 4 to 53. 28. The anti-NaPi2b antibody of any one of the preceding items, wherein the antibody comprises at least one (e.g., two) heavy and light chains, preferably of any one of the preceding items. 29. The antibody comprises one or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid substitutions (or mutations), preferably in the following: CDRs (e.g., CDR1, CDR2, CDR3, e.g., CDR-H1, CDR-H2, CDR-H3, CDR-H1, CDR-L1, CDR-L2, and / or CDR-L3, e.g., those described in any one of the preceding items, e.g., the sequence listing disclosed herein), V H (variable region heavy chain), V L (variable region light chain), C H (constant region heavy chain), or C L The anti-NaPi2b antibody of any one of the preceding items, wherein the nucleotide sequence is located within one or more regions selected from the group consisting of: (constant region light chain), F(ab), and / or Fc region (e.g., as defined in Figure 1 herein). 30. Contains one or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10) highly conservative, conservative, or equivalent amino acid substitutions (or mutations), for example, "conservative or equivalent substitutions" means the substitutions listed under "exemplary substitutions" in Table I below, and "highly conservative" substitutions, as used herein, mean the substitutions set out under the heading "preferred substitutions" in Table I below; TIFF2025536308000142.tif134157 Preferably, the one or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10) highly conservative, conservative, or equivalent amino acid substitutions (or mutations) are in any of the following: CDRs (e.g., CDR1, CDR2, CDR3, e.g., CDR-H1, CDR-H2, CDR-H3, CDR-H1, CDR-L1, CDR-L2, and / or CDR-L3, e.g., those described in any one of the preceding items, e.g., the sequence listing disclosed herein), V H (variable region heavy chain), V L (variable region light chain), C H (constant region heavy chain), or C L The anti-NaPi2b antibody of any one of the preceding items, wherein the nucleotide sequence is located within one or more regions selected from the group consisting of: (constant region light chain), F(ab), and / or Fc region (e.g., as defined in Figure 1 herein). 31. The antibody of any one of the preceding items, wherein the antibody has a HMWS (high molecular weight species) percentage (%) of less than 5% (e.g., as shown in Figure 20). 32. A hybridoma producing any one of the monoclonal antibodies described in the preceding items. 33. A nucleic acid encoding any one of the antibodies described above. 34. An expression vector comprising at least one nucleic acid molecule according to any one of the preceding items. 35. An isolated host cell (e.g., an isolated recombinant host cell) comprising the vector and / or nucleic acid of any one of the preceding items. 36. An antibody drug conjugate (ADC) comprising the anti-NaPi2b antibody of any one of the preceding items (e.g., obtained according to Example 1 herein and / or having the characteristics described in Example 1 and / or Example 2 and / or Example 3 herein). 37. The anti-NaPi2b antibody is selected from the group consisting of one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) cytotoxic moieties (e.g., cytotoxic payloads, such as tubulin inhibitors, e.g., topoisomerase I inhibitors, e.g., auristatins or camptothecins, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan (e.g., CAS No.: 171335-80-1), preferably via one or more linkers, more preferably via one or more phosphonamidate linkers. 38. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the anti-NaPi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, even more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably 8) camptothecin (e.g., exatecan) cytotoxic moieties, preferably via one or more linkers, more preferably via one or more phosphonamidate linkers. 39. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the anti-NaPi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, even more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) exatecan cytotoxic moieties via one or more linkers, preferably via one or more phosphonamidate linkers. 40. An antibody-drug conjugate (ADC) comprising a humanized monoclonal NaPi2b-specific IgG1 antibody conjugated to a cytotoxic payload; where: (a) the cytotoxic payload is selected from the group consisting of camptothecins, maytansinoids, calicheamicins, duocarmycins, tubulysins, amatoxins, dolastatins, and auristatins such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof; and / or (b) the cytotoxic payload is a camptothecin moiety C selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, ciratecan, cositecan, and gimatecan; and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker L comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, wherein the releasing unit is cleavable by a protease; The antibody drug conjugate (ADC) of any one of the preceding items. 41. An anti-NaPi2b antibody is administered to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably 8) camptothecin (exatecan)-induced cell injury. 4. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the antibody drug conjugate (ADC) is conjugated to a payload moiety via conjugation with an ethynyl phosphonamidate linker (e.g., to all eight interchain cysteine ​​residues), preferably each phosphonamidate linker having at least one PEG24 moiety (e.g., to prevent aggregation of the ADC), and more preferably the ADC has up to eight of the linker payload moieties and eight PEG24 moieties. 42. Formula (I): TIFF2025536308000143.tif34128 or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, Ab is an anti-NaPi2b antibody as defined in any one of the preceding items; TIFF2025536308000144.tif6128 is a double bond or TIFF2025536308000145.tif6128 is a single bond; If TIFF2025536308000146.tif6128 is a double bond, V is absent, or TIFF2025536308000147.tif6128 is a single bond, V is H or (C1-C8) alkyl; TIFF2025536308000148.tif6128 is a double bond, X is R3-C, or If TIFF2025536308000149.tif6128 is a single bond, then X is TIFF2025536308000150.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20; Optionally, the antibody drug conjugate (ADC) of any one of items 36 to 41. 43. R 3 is H or (C1-C8) alkyl; preferably, R 3 is H; R 4 When present, is H or (C1-C8) alkyl; preferably, R 4 is H, if present; R 5 When present, is H or (C1-C8) alkyl; preferably, R 5 is H, if present; R 6 When present, is H or (C1-C8) alkyl; preferably, R 6 is H, if present; and R 7 When present, is H or (C1-C8) alkyl; preferably, R 7 is H, if present, Item 42. Antibody drug conjugates (ADCs). 44. TIFF2025536308000151.tif6128 is a double bond; V is absent; X is R3-C; and R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl; more preferably, R 3 44. The antibody drug conjugate (ADC) of item 42 or 43, wherein 45. TIFF2025536308000152.tif6128 is a single bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000153.tif9128;R 3is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; more preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 4 is H or (C1-C8) alkyl, preferably R 4 44. The antibody drug conjugate (ADC) of item 42 or 43, wherein 46. ​​The antibody drug conjugate (ADC) of any one of paragraphs 42 to 45, wherein Y is NH. 47. The antibody drug conjugate (ADC) of any one of items 42 to 46, wherein the connector unit CU is cleavable. 48. The antibody-drug conjugate (ADC) of item 47, wherein the connector unit CU is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction. 49. The antibody drug conjugate (ADC) of item 48, wherein the connector unit CU is cleavable by a protease, preferably a cathepsin, such as cathepsin B. 50. The antibody drug conjugate (ADC) of any one of paragraphs 42 to 49, wherein the connector unit (CU) comprises a valine-citrulline moiety. 51. The connector unit CU is TIFF2025536308000154.tif50128, where # indicates the point of attachment to Y; * 50. The antibody drug conjugate (ADC) of item 50, showing the point of attachment to the cytotoxic moiety CM. 52. The antibody drug conjugate (ADC) of any one of paragraphs 42 to 49, wherein the connector unit CU comprises a valine-alanine moiety. 53. The connector unit CU is TIFF2025536308000155.tif37128, wherein: *53. The antibody drug conjugate (ADC) of item 52, wherein indicates the point of attachment to Y and ## indicates the point of attachment to the cytotoxic moiety. 54. The antibody-drug conjugate (ADC) of any one of items 42 to 46, wherein the linker is not cleavable. 55. R 1 is a polyethylene glycol unit. 56. The polyethylene glycol unit has the structure: 55. An antibody-drug conjugate (ADC) of item 55, comprising 1 to 100 subunits having TIFF2025536308000156.tif9128. 57. R 1 but, TIFF2025536308000157.tif15128, wherein: TIFF2025536308000158.tif9128 indicates the position of O; K F -H, -PO3H, -(C1~C 10 ) alkyl, -(C1-C 10 )Alkyl-SO3H, -(C2~C 10 )Alkyl-CO2H, -(C2~C 10 ) Alkyl-OH, -(C2-C 10 )Alkyl-NH2, -(C2~C 10 ) alkyl-NH(C1-C3) alkyl, and -(C2-C 10 ) alkyl-N((C1-C3) alkyl)2; and o is an integer ranging from 1 to 100; 57. The antibody-drug conjugate (ADC) of any one of items 42 to 56. 58. K F 58. The antibody drug conjugate (ADC) of item 57, wherein 59. The antibody-drug conjugate (ADC) of item 57 or 58, wherein o is in the range of 8 to 30. 60. The antibody-drug conjugate (ADC) of item 59, wherein o is in the range of 20 to 28. 61. The antibody drug conjugate (ADC) of item 60, wherein o is 22, 23, 24, 25, or 26. 62. The antibody-drug conjugate (ADC) of item 59, wherein o is in the range of 8 to 16. 63. The antibody drug conjugate (ADC) of item 62, wherein o is 10, 11, 12, 13, or 14. 64. The antibody drug conjugate (ADC) of any one of items 42 to 63, wherein the cytotoxic moiety CM is selected from the group consisting of camptothecins, maytansinoids, calicheamicins, duocarmycins, tubulysins, amatoxins, dolastatins, and auristatins such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof. 65. The antibody-drug conjugate (ADC) of item 64, wherein the cytotoxic moiety CM is a camptothecin moiety. 66. The antibody drug conjugate (ADC) of item 65, wherein the camptothecin moiety is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, ciratecan, cositecan, and gimatecan. 67. The cytotoxic moiety CM has the formula: The antibody drug conjugate (ADC) of item 66, which is exatecan having TIFF2025536308000159.tif56128. 68. The cytotoxic moiety CM has the formula: The antibody drug conjugate (ADC) of item 67, which is exatecan having TIFF2025536308000160.tif53128. 69. The antibody drug conjugate (ADC) of item 67 or 68, wherein exatecan is attached to the connector unit CU via an amino group. 70. The antibody-drug conjugate (ADC) of any one of items 42 to 69, wherein the number of cytotoxic moieties CM, in particular the number of camptothecin moieties, per receptor-binding molecule is 1 to 14, preferably 2 to 14, more preferably 4 to 14, even more preferably 5 to 12, even more preferably 6 to 12, even more preferably 7 to 10, and even more preferably 8. 71. The antibody-drug conjugate (ADC) of any one of items 42 to 69, wherein the number of cytotoxic moieties CM, in particular the number of camptothecin moieties, per receptor-binding molecule is 1 to 14, preferably 1 to 12, more preferably 2 to 10, even more preferably 2 to 8, even more preferably 2 to 6, even more preferably 3 to 5, and even more preferably 4. 72. The antibody drug conjugate (ADC) of any one of items 42 to 69, wherein m is an integer in the range of 1 to 4, preferably 1 or 2, more preferably 1; and n is an integer in the range of 1 to 20, preferably 1 to 10, more preferably 2 to 10, even more preferably 4 to 10, even more preferably 6 to 10, even more preferably 7 to 10, even more preferably 8. 73. The antibody drug conjugate of any one of items 42 to 69, wherein m is an integer in the range of 1 to 4, preferably 1 or 2, more preferably 1; and n is an integer in the range of 1 to 20, preferably 1 to 10, more preferably 2 to 8, even more preferably 3 to 6, even more preferably 4 or 5, even more preferably 4. 74. Formula (I): TIFF2025536308000161.tif34128 or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, Ab is an anti-NaPi2b antibody as defined in any one of the preceding items; TIFF2025536308000162.tif6128 is a double bond or TIFF2025536308000163.tif6128 is a single bond; If TIFF2025536308000164.tif6128 is a double bond, V is absent, or TIFF2025536308000165.tif6128 is a single bond, V is H; TIFF2025536308000166.tif6128 is a double bond, X is R3-C, or If TIFF2025536308000167.tif6128 is a single bond, then X is TIFF2025536308000168.tif9128; Y is NH; R 1 The structure: TIFF2025536308000169.tif15128, During the ceremony, TIFF2025536308000170.tif9128 indicates the position of O. K F is H, and o is an integer ranging from 8 to 30; R 3 is H; R 4 is H; CU has the following structure: TIFF2025536308000171.tif52128, where # indicates the point of attachment to Y; * indicates the point of attachment to the camptothecin moiety (CM); CM is the camptothecin moiety; m is 1; and n is an integer ranging from 1 to 10; Optionally, the antibody drug conjugate (ADC) of any one of items 42 to 73. 75. TIFF2025536308000172.tif6128 is a double bond; V is absent; X is R3-C; and R 3 75. The antibody drug conjugate (ADC) of item 74, wherein 76. TIFF2025536308000173.tif6128 is a single bond; V is H; X is TIFF2025536308000174.tif9128;R 3 is H; and R 4 75. The antibody drug conjugate (ADC) of item 74, wherein 77. The camptothecin moiety CM has the formula: The antibody drug conjugate (ADC) of any one of items 74 to 76, which is exatecan having TIFF2025536308000175.tif53128. 78. The antibody drug conjugate (ADC) of item 77, wherein exatecan is attached to the connector unit CU via an amino group. 79. The antibody drug conjugate (ADC) of any one of items 74 to 78, wherein o is in the range of 20 to 28. 80. The antibody drug conjugate (ADC) of item 79, wherein o is 22, 23, 24, 25, or 26. 81. The antibody-drug conjugate (ADC) of any one of items 74 to 80, wherein n is in the range of 2 to 10. 82. The antibody drug conjugate (ADC) of item 81, wherein n is 8. 83. The antibody drug conjugate (ADC) of item 81, wherein n is 4. 84. The compound of formula (Ia): TIFF2025536308000176.tif69157, wherein Ab is an anti-NaPi2b antibody as defined in any one of the preceding items. Optionally, the antibody drug conjugate (ADC) of any one of items 74 to 82. 85. The antibody-drug conjugate (ADC) of item 64, wherein the cytotoxic moiety CM is an auristatin. 86. The antibody-drug conjugate (ADC) of item 85, wherein the cytotoxic moiety is monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF). 87. The antibody-drug conjugate (ADC) of item 86, wherein the cytotoxic moiety is monomethyl auristatin E (MMAE). 88. The following: (a) Formula I: TIFF2025536308000177.tif55135(b) Formula II: TIFF2025536308000178.tif46128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (c) Formula III: TIFF2025536308000179.tif42128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (d) Formula IV: TIFF2025536308000180.tif41128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (e) Formula V: TIFF2025536308000181.tif43128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (f) Formula VI: TIFF2025536308000182.tif45128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (g) Formula VII: TIFF2025536308000183.tif41128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (h) Formula VIII: TIFF2025536308000184.tif41128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (i) Formula IX: TIFF2025536308000185.tif43128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (j) Formula X: TIFF2025536308000186.tif41128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (k) Formula XI: TIFF2025536308000187.tif43128 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (l) Formula XII: TIFF2025536308000188.tif44132 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (m)Formula XIII: TIFF2025536308000189.tif48131 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (n) Formula XIV: TIFF2025536308000190.tif45133 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (o)Formula XV: TIFF2025536308000191.tif45136 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)); (p)Formula XVI: TIFF2025536308000192.tif51139 (wherein n is in the range of 0 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8)) having a formula selected from the group consisting of: where: TIFF2025536308000193.tif32128 is an anti-NaPi2b antibody defined in any one of the preceding items; The antibody drug conjugate (ADC) of any one of the preceding items. 89. (a) the anti-Napi2b monoclonal antibody can specifically recognize human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2) overexpressed in cancer cells; and (b) upon binding of an antibody drug conjugate (ADC) to overexpressed Napi2b in cancer cells, the ADC can be internalized by the cells and transported into the lysosomal compartment, where preferably lysosomal proteases (e.g., cathepsin B) can liberate the cytotoxic payload from the ADC; The antibody drug conjugate (ADC) of any one of the preceding items. 90. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the percentage of HMWS (high molecular weight species) of the antibody is less than 5% (e.g., as shown in Figure 20). 91. Formula (II): TIFF2025536308000194.tif29128 or a pharmaceutically acceptable salt or solvate thereof: During the ceremony, TIFF2025536308000195.tif6128 is a triple bond or TIFF2025536308000196.tif6128 is a double bond; If TIFF2025536308000197.tif6128 is a triple bond, V is absent, or TIFF2025536308000198.tif6128 is a double bond, V is H or (C1-C8) alkyl; TIFF2025536308000199.tif6128 is a triple bond, X is R3-C, or If TIFF2025536308000200.tif6128 is a double bond, then X is TIFF2025536308000201.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; and m is an integer ranging from 1 to 10. 92. R 3 is H or (C1-C8) alkyl; preferably, R 3 is H; R 4 When present, is H or (C1-C8) alkyl; preferably, R 4 is H, if present; R 5 When present, is H or (C1-C8) alkyl; preferably, R 5 is H, if present; R 6 When present, is H or (C1-C8) alkyl; preferably, R 6 is H, if present; and R 7 When present, is H or (C1-C8) alkyl; preferably, R 7 is H, if present, Compound of item 91. 93. TIFF2025536308000202.tif6128 is a triple bond; V is absent; X is R3-C; and R 3is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl; more preferably, R 3 93. The compound of item 91 or 92, wherein is H. 94. TIFF2025536308000203.tif6128 is a double bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000204.tif9128;R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 4 is H or (C1-C8) alkyl, more preferably R 4 93. The compound of item 91 or 92, wherein is H. 95. Ab, V, X, Y, R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , CU, CM, m, and n are as defined in any one of items 42 to 90; preferably, the compound of any one of items 91 to 94, wherein Y is NH. 96. (a) conjugating the antibody of any one of the preceding items to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably 8) cytotoxic moieties (e.g., a cytotoxic payload, such as a tubulin inhibitor, e.g., a topoisomerase-I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan), preferably via one or more linkers, more preferably via one or more phosphoamidate linkers. A method for producing an antibody drug conjugate (ADC), comprising: 97. A method of producing an antibody drug conjugate (ADC) according to any one of the preceding items, in which an anti-Napi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, even more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) camptothecin (e.g., exatecan) cytotoxic moieties, preferably via one or more linkers, more preferably via one or more phosphonamidate linkers. 98. A method of producing an antibody drug conjugate (ADC) according to any one of the preceding items, in which an anti-Napi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, even more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) exatecan cytotoxic moieties via one or more linkers, preferably via one or more phosphonamidate linkers. 99. An anti-Napi2b antibody is fused to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) camptothecin (e.g., exatecan) cytotoxic moieties (e.g., all 8). and wherein the antibody drug conjugates (ADCs) are conjugated via conjugation with an ethynyl phosphonamidate linker (to all interchain cysteine ​​residues); preferably, each phosphonamidate linker has at least one PEG moiety having up to 24 PEG units (e.g., to prevent aggregation of the antibody drug conjugate (ADC)), and more preferably, the ADC has up to 8 of the linker payload moieties and 8 PEG24 moieties. 100. A method for producing an antibody drug conjugate (ADC) according to any one of the preceding items, comprising: The ADC comprises a humanized monoclonal NaPi2b-specific IgG1 antibody conjugated to a cytotoxic payload; (a) the cytotoxic payload is selected from the group consisting of camptothecins, maytansinoids, calicheamicins, duocarmycins, tubulysins, amatoxins, dolastatins, and auristatins such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof; and / or (b) the cytotoxic payload is a camptothecin moiety C selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, ciratecan, cositecan, and gimatecan; and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker L comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, which is cleavable by a protease; The method. 101. Formula (II) TIFF2025536308000205.tif29128 (in the formula, TIFF2025536308000206.tif6128 is a triple bond or TIFF2025536308000207.tif6128 is a double bond; If TIFF2025536308000208.tif6128 is a triple bond, V is absent, or TIFF2025536308000209.tif6128 is a double bond, V is H or (C1-C8) alkyl; TIFF2025536308000210.tif6128 is a triple bond, X is R3-C, or If TIFF2025536308000211.tif6128 is a double bond, then X is TIFF2025536308000212.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; and m is an integer ranging from 1 to 10. or a pharmaceutically acceptable salt or solvate thereof, Formula (III): TIFF2025536308000213.tif13128 (wherein Ab is an anti-NaPi2b antibody defined in any one of the preceding items; and n is an integer ranging from 1 to 20) of thiol-containing molecules and reacting the compound with As a result, the compound of formula (I) TIFF2025536308000214.tif34128 (in the formula, Ab is an anti-NaPi2b antibody as defined in any one of the preceding items; In the compound of formula (II) If TIFF2025536308000215.tif6128 is a triple bond, TIFF2025536308000216.tif6128 is a double bond, or In the compound of formula (II) If TIFF2025536308000217.tif6128 is a double bond, TIFF2025536308000218.tif6128 is a single bond; If TIFF2025536308000219.tif6128 is a double bond, V is absent, or TIFF2025536308000220.tif5128 is a single bond, V is H or (C1-C8) alkyl; TIFF2025536308000221.tif6128 is a double bond, X is R3-C, or If TIFF2025536308000222.tif6128 is a single bond, then X is TIFF2025536308000223.tif9128; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20. or a pharmaceutically acceptable salt or solvate thereof. Optionally, a method for preparing an antibody drug conjugate (ADC) of any one of items 96 to 100, comprising: 102. R 3 is H or (C1-C8) alkyl; preferably, R 3 is H; R 4 When present, is H or (C1-C8) alkyl; preferably, R 4 is H, if present; R 5 When present, is H or (C1-C8) alkyl; preferably, R 5 is H, if present; R 6 When present, is H or (C1-C8) alkyl; preferably, R 6 is H, if present; and R 7 When present, is H or (C1-C8) alkyl; preferably, R 7is H, if present, Item 101 method. 103. TIFF2025536308000224.tif6128 is a triple bond; V is absent; X is R3-C; R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue, preferably R 3 is H or (C1-C8) alkyl, more preferably R 3 is H, and The method of item 101 or 102, in which TIFF2025536308000225.tif6128 is a double bond. 104. TIFF2025536308000226.tif6128 is a double bond; V is H or (C1-C8) alkyl, preferably V is H; X is TIFF2025536308000227.tif9128;R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 is H or (C1-C8) alkyl, more preferably R 3 is H;R 4 is H or (C1-C8) alkyl, preferably R 4 is H; and The method of item 101 or 102, in which TIFF2025536308000228.tif6128 is a single bond. 105. The method of any one of items 101 to 104, wherein the reaction is carried out under neutral pH or slightly basic conditions, preferably at pH 6 to 10. 106. The method of any one of items 101 to 105, further comprising the step of reducing at least one disulfide bridge of the antibody in the presence of a reducing agent, thereby forming a thiol group (SH). 107. The reducing agent is selected from the group consisting of tris(2-carboxyethyl)phosphine (TCEP), dithiothreitol (DTT), sodium dithionite, sodium thiosulfate, and sodium sulfite; Preferably, the reducing agent is tris(2-carboxyethyl)phosphine (TCEP). 108. The method according to item 106 or 107, wherein the step of reducing at least one disulfide bridge comprises using about 1 to about 3 equivalents, preferably about 1 to about 2 equivalents, more preferably about 1 equivalent of a reducing agent per disulfide bridge to be reduced. 109. The method of any one of items 101 to 108, wherein the thiol-containing molecule of formula (III) is reacted with about 1 to about 4 equivalents, preferably about 1 to about 3 equivalents, more preferably about 1 to about 2 equivalents, and even more preferably about 1.5 equivalents of a compound of formula (II) per thiol group (SH). 110. The method of any one of items 101 to 109, wherein the step of reacting the compound of formula (II) with the thiol-containing molecule of formula (III) is carried out in an aqueous medium. 111. Ab, V, X, Y, R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , CU, CM, m, and n are as defined in any one of items 42 to 90; preferably, Y is NH2. 112. An antibody drug conjugate (ADC) produced by the method of any one of the preceding items. 113. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the antibody has a percent HMWS (high molecular weight species) of less than 5%, preferably thereby reducing aggregation of the ADC and / or reducing toxicity of the ADC to normal (e.g., non-cancerous) tissue. 114. An antibody-drug conjugate (ADC) according to any one of the preceding items, wherein the drug-to-antibody ratio (DAR) is in the range of 0 to 20, preferably in the range of 1 to 20, more preferably in the range of 2 to 12, most preferably in the range of 4 to 10, and even more preferably in the range of 4 to 8. 115. The antibody drug conjugate (ADC) of any one of the preceding items, wherein the DAR of the ADC is 4 or 8, preferably 8. 116. A composition or kit comprising the anti-Napi2b, antibody drug conjugate (ADC), hybridoma, nucleic acid, expression vector, and / or host cell of any one of the preceding items. 117. The composition of any one of the preceding items, which is a pharmaceutical and / or diagnostic composition. 118. The composition or kit of any one of the preceding items, wherein the drug (e.g., cytotoxic moiety (e.g., a cytotoxic payload, e.g., a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethyl auristatin E) or MMAF (monomethyl auristatin F), e.g., exatecan) to antibody ratio (DAR) is in the range of 0 to 20, preferably in the range of 1 to 20, more preferably in the range of 2 to 12, most preferably in the range of 4 to 10, and even more preferably in the range of 4 to 8. 119. A composition or kit comprising the anti-NaPi2b antibody, antibody-drug conjugate (ADC), hybridoma, nucleic acid, expression vector, and / or host cell of any one of the preceding items. 120. A method for treating, ameliorating, preventing, and / or diagnosing cancer, preferably wherein the cancer is a solid cancer and / or a metastatic cancer, more preferably wherein the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, fallopian tube cancer, and lung adenocarcinoma (e.g., as in Examples 2 and / or 3 herein), the method comprising the step of administering a therapeutically or prophylactically effective amount of any one of the antibodies, antibody drug conjugates (ADCs), nucleic acids, expression vectors, host cells, compositions, or kits of the preceding items. 121. The antibody, antibody drug conjugate (ADC), nucleic acid, expression vector, host cell, composition, or kit of any one of the preceding items for use as a medicament and / or in therapy. 122. The antibody, antibody drug conjugate (ADC), nucleic acid, expression vector, host cell, composition, or kit of any one of the preceding items for use in one or more of the following methods: (a) a method for the treatment, amelioration, prevention, and / or diagnosis of cancer, wherein preferably the cancer is a solid cancer and / or a metastatic cancer, and more preferably the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, fallopian tube cancer, lung adenocarcinoma (e.g., as in Examples 2 and / or 3 herein); (b) methods for monitoring cancer progression and / or assessing the effectiveness of cancer treatments; (c) a method for screening candidate compounds for anti-cancer activity; (d) methods for altering the resistance of cancer cells to chemotherapy; (e) methods for sensitizing cancer cells to chemotherapy; (f) a method for inhibiting the proliferation of cancer cells expressing NaPi2b; (g) methods for producing or preparing antibodies; (h) methods for immunizing non-human animals; (i) methods for the preparation of hybridomas; (j) Any one of the preceding methods; (k) Any one of methods (a) to (j), which is an in vivo, in vitro, or ex vivo method. 123. Use of the antibody, antibody drug conjugate (ADC), nucleic acid, expression vector, host cell, composition, or kit of any one of the preceding items for one or more of the following: (a) the treatment, amelioration, prevention, and / or diagnosis of cancer (preferably, the cancer is a solid cancer and / or a metastatic cancer, and more preferably, the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, fallopian tube cancer, and lung adenocarcinoma (e.g., as in Examples 2 and / or 3 herein)); (b) monitoring the progression of cancer and / or assessing the effectiveness of cancer treatments; (c) screening candidate compounds for anticancer activity; (d) altering the resistance of cancer cells to chemotherapy; (e) sensitizing cancer cells to chemotherapy; (f) inhibiting the proliferation of cancer cells expressing NaPi2b; (g) production or preparation of antibodies; (h) immunizing a non-human animal; (i) Preparation of hybridomas; (j) In any one of the preceding methods; (k) Any one of (a) to (j) above, which is an in vivo, in vitro, or ex vivo use. 124. An antibody drug conjugate (ADC), composition, kit, method, and / or use according to any one of the preceding items, wherein the dose (e.g., a therapeutic dose, e.g., an effective therapeutic dose, and / or a daily dose, e.g., a single daily dose or multiple daily doses, and / or a total dose) comprises or consists of an ADC of any one of the preceding items in an amount of at least about 10 mg per kg of body weight of the subject (e.g., an animal or human patient), preferably about 10 to about 20 mg / kg (e.g., 10 mg / kg, 11 mg / kg, 12 mg / kg, 13 mg / kg, 14 mg / kg, 15 mg / kg, 16 mg / kg, 17 mg / kg, 18 mg / kg, 19 mg / kg, 20 mg / kg, or more), or a total amount of at least about 700 to 2000 mg of an ADC of any one of the preceding items (e.g., as in Example 2 and / or Example 3 herein). 125. The antibody drug conjugate (ADC), composition, kit, method, and / or use according to any one of the preceding items, wherein a dose (e.g., a therapeutic dose, e.g., an effective therapeutic dose, and / or a daily dose, e.g., a single daily dose or multiple daily doses, and / or a total dose) of the ADC of any one of the preceding items is administered (e.g., orally or intravenously) one or more times (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 times, e.g., every two or three days or once or twice a week), with or without dose escalation (e.g., as in Example 2 and / or Example 3 herein), over a period of at least about one week (e.g., 1 to 4 weeks, e.g., 3 weeks, 1 month, or 2 months). 127. The antibody drug conjugate (ADC), composition, kit, method, and / or use according to any one of the preceding items, wherein the treatment regimen comprises or consists of one or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10, e.g., every 2 or 3 days or once or twice a week) administration (e.g., oral or intravenous) of a dose (e.g., a therapeutic dose, e.g., an effective therapeutic dose, and / or a daily dose, e.g., a single dose or multiple doses per day, and / or a total dose) of the ADC of any one of the preceding items, with or without dose escalation (e.g., as in Example 2 and / or Example 3 herein), over a period of at least about 1 week (e.g., 1-4 weeks, e.g., 3 weeks, 1 month, or 2 months). 128. The antibody drug conjugate (ADC), composition, kit, method, and / or use of any one of the preceding items, further comprising one or more therapeutic agents (e.g., anti-cancer agents or drugs). 129. The antibody drug conjugate (ADC), composition, kit, method, and / or use of any one of the preceding items, further comprising the administration (prior, simultaneous, or subsequent) of one or more therapeutic agents (e.g., anti-cancer agents or drugs).

[0275] It should be noted that, as used herein, the singular forms "a," "an," and "the" include plural referents unless the context specifically dictates otherwise. Thus, for example, reference to "a reagent" includes one or more of such various reagents, and reference to "the method" includes reference to equivalent steps and methods known to those skilled in the art that may be modified or used in place of the methods described herein.

[0276] Unless otherwise specified, the term "at least" preceding a series of elements is to be understood to refer to every element in the series. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the present invention.

[0277] The term "and / or" whenever used herein includes the meaning of "and", "or" and "all or any other combination of the elements connected by said term".

[0278] The terms "about" or "approximately," as used herein, mean within 20%, preferably within 10%, and more preferably within 5% of a given value or range.

[0279] The terms "less than" or even "more than" do not include that specific number.

[0280] For example, "fewer than 20" means fewer than a specified number. Similarly, "more than" or "greater than" means more than or above a specified number, for example, "more than 80%" means more than or above 80% of a specified number.

[0281] Throughout this specification and the claims that follow, unless the context dictates otherwise, the word "comprise," and variations such as "comprises" and "comprising," are understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integers and steps or group of integers and steps. As used herein, the term "comprising" can be replaced with the terms "containing" or "including," or, as sometimes used herein, the term "having." As used herein, "consisting of" excludes any element, step, or ingredient not specified.

[0282] The term "including" means "including but not limited to." "Including" and "including but not limited to" are used interchangeably.

[0283] It is to be understood that this invention is not limited to the particular methodology, protocols, materials, reagents, and substances, etc., described herein and as such may vary. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which is defined solely by the claims.

[0284] All publications cited throughout the text of this specification, whether supra or infra, including all patents, patent applications, scientific publications, manuals, etc., are incorporated herein by reference in their entirety. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such disclosure by virtue of prior invention. In the event that material incorporated by reference contradicts or is inconsistent with this specification, the present specification shall take precedence over any such material.

[0285] The contents of all documents and patents cited herein are incorporated by reference in their entirety. [Example]

[0286] Examples of the invention A further understanding of the present invention and its advantages will become apparent from the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0287] Example 1: General information Chemicals, solvents, and antibodies Chemicals and solvents were purchased from Merck (Merck group, Germany), TCI (Tokyo Chemical Industry Co., Ltd., Japan), Iris Biotech (Iris Biotech GmbH, Germany), MCE (MedChemExpress, USA), and Carl Roth (Carl Roth GmbH + Co. KG, Germany) and used without further purification. Dry solvents were purchased from Merck (Merck group, Germany). PEG24 was purchased from BiochemPEG (Pure Chemistry Scientific Inc., United States).

[0288] Preparative HPLC Preparative HPLC was performed on a small scale on a BUCHI Pure C-850 Flash-Prep system (BUCHI Labortechnik AG, Switzerland) using a VP 250 / 10 Macherey-Nagel Nucleodur C18 HTec Spum column (Macherey-Nagel GmbH & Co. Kg, Germany). The following gradient was used: Method C: (A = HO + 0.1% TFA (trifluoroacetic acid), B = MeCN (acetonitrile) + 0.1% TFA, flow rate 6 ml / min, 30% B 0-5 min, 30-70% B 5-35 min, 99% B 35-45 min. For larger scale runs, a VP 250 / 21 Macherey-Nagel Nucleodur C18 HTec Spum column (Macherey-Nagel GmbH & Co. Kg, Germany) was used and the following gradient was used: Method D: (A = HO + 0.1% TFA (trifluoroacetic acid), B = MeCN (acetonitrile) + 0.1% TFA, flow rate 14 ml / min, 30% B 0-5 min, 30-70% B 5-35 min, 99% B 35-45 min.

[0289] LC-MS Small molecules, linker payloads, antibodies, and ADCs were analyzed using a Waters H-class instrument equipped with a 4-solvent manager, a Waters sample manager-FTN, a Waters PDA detector, and a Waters column manager, using an Acquity UPLC Protein BEH C4 column (300 Å, 1.7 μm, 2.1 mm × 50 mm) for antibodies and ADCs. Samples were eluted at a column temperature of 80 °C. The following gradient was used: A: 0.1% formic acid in HO, B: 0.1% formic acid in MeCN. 25% B 0-1 min, 0.4 mL / min; 25-95% B 1-3.5 min, 0.2 mL / min; 95% B 3.5-4.5 min, 0.2 mL / min; 95-25% B 4.5-5 min, 0.4 mL / min; 25-95% B 5-5.5 min, 0.4 mL / min; 95-25% B 5.5-7.5 min, 0.4 mL / min. Mass spectrometry was performed using a Waters XEVO G2-XS QTof analyzer. Proteins were ionized in positive ion mode using a 40 kV cone voltage. Raw data were analyzed using MaxEnt 1. Small molecule and linker payloads were analyzed using an Acquity UPLC-BEH C18 column (300 Å, 1.7 μm, 2.1 mm x 50 mm). In this case, the sample was eluted at a column temperature of 45 °C and a flow rate of 0.4 mL / min. The following gradient was used: A: 0.1% formic acid in HO; B: 0.1% formic acid in MeCN. 2% B from 0 to 1 min, 2 to 98% B from 1 to 5 min, 98% B from 5 to 5.5 min, 98 to 2% B from 5.5 to 6 min, 2% B from 6 to 7 min.

[0290] CDR mutagenesis and antibody expression 22 × 10 for parent antibody CDR mutagenesis efforts 8 A phage display library containing sequences (66% functional) was prepared. This library was based on homology modeling of the antibody Fv region, selection of surface CDR residues potentially involved in antigen binding (VH: 18 positions, VK: 16 positions identified), and NGS data (approximately 2 × 10 6This was based on an analysis of amino acid usage at each position in the IgG sequence (Figure 1). Panning of the CDR-mutated phage library to select antibodies with improved affinity was performed using four rounds of stepwise antigen restriction achieved by increasing cell dilution against the antigen / Napi2b-expressing cells. From each round of panning, 384 clones (1536 clones in total) were selected and produced as soluble scFv antibodies in Escherichia coli (E. coli). They were then screened for binding to human Napi2b-expressing HEK293 cells and parental HEK293 cells using flow cytometry analysis. A signal-to-noise ratio (N / S) of greater than 12 between the MFI of the positive cell line and the MFI of the negative cell line was selected as the hit selection criterion. Following the aforementioned selection criteria, 375 clones were identified and their DNA sequences were determined. From these results, 255 distinct antibody sequences were identified, and the off-rates of these clones were further analyzed using BLI technology. Specifically, biotinylated Napi2b antigen was immobilized on a streptavidin sensor, and the binding and dissociation of scFvs were measured. Off-rate kinetics were modeled, and clones that met the following criteria were ranked: significant binding response and high modeling accuracy must be achieved. Five antibody clones / sequences were selected for further analysis: AV-15, AV-18, AV-21, AV-25, and AV-29 (Figure 1).

[0291] Next, antibodies were transiently expressed in Expi-CHO-S cells (Thermo Fisher) by co-transfecting the cells with pcDNA3.4 expression plasmids (Thermo Fisher) encoding the heavy and light chains of each sequence at a 1:1 ratio using the Expi-CHO transfection system (Thermo Fisher). Cells were harvested by centrifugation at 300 g for 5 minutes at 4°C. To remove particulates from the supernatant, the supernatant was centrifuged at 4000-5000 g for 30 minutes at 4°C. For further clarification, the supernatant was passed through a 0.22 μm filter. Antibodies were purified from the clarified and filtered supernatant by Protein A chromatography and analyzed by HPLC-SEC, HPLC-HIC, LC-MS, and SDS-PAGE.

[0292] Preparative size-exclusion chromatography Protein purification by size exclusion chromatography was performed using an AKTA Pure FPLC system (GE Healthcare, United States) equipped with an F9-C fraction collector.

[0293] Measurement of ADC concentration ADC concentrations were measured in 96-well plates using the Pierce™ Rapid Gold BCA Protein Assay Kit (Thermo Fisher Scientific, USA) and Bradford Reagent B6916 (Merck, Germany) with pre-diluted protein assay standards of bovine gamma globulin (Thermo Fisher Scientific, USA). Results from both assays were arithmetically averaged.

[0294] ADC and antibody sample preparation for MS For deglycosylation of antibodies and ADCs, 0.5 μl of PNGase-F solution (Pomega, Germany, recombinant, cloned from Elizabethkingia miricola, 10 μl / μl) and 5 μL of 100 mM DTT aqueous solution were added to 50 μl of PBS containing 0.2 mg / mL antibody or ADC, and the solution was incubated at 37°C for at least 2 hours. Glycosylated mAbs and ADCs were incubated with 10 mM DTT at a concentration of 0.2 mg / mL for 1 hour. 2 μl of each sample was injected, and the samples were subjected to LC / MS.

[0295] Analytical size exclusion chromatography Analytical size-exclusion chromatography (A-SEC) of ADCs was performed on a Vanquish Flex UHPLC system equipped with a DAD detector, a split sampler FT (4 °C), a column compartment H (25 °C), and a binary pump F (Thermo Fisher Scientific, USA) using a MAbPac SEC-1 300 Å, 4 × 300 mm column (Thermo Fisher Scientific, USA) at a flow rate of 0.15 mL / min. Separation of the various ADC / mAb populations was achieved by a 30-minute isocratic gradient using pH 7 phosphate buffer (20 mM NaHPO / NaHPO, 300 mM NaCl, 5% v / v isopropyl alcohol) as the mobile phase. 8 μg of ADC / mAb was loaded onto the column for A-SEC analysis. UV chromatograms were recorded at 220 nm and 280 nm.

[0296] Analytical hydrophobic interaction chromatography Measurements were performed on a Vanquish Flex UHPLC system (2.9) using a MabPac HIC Butyl 4.6 x 100 mm column (Thermo Fischer Scientific, USA). Separation of the various ADCs / antibodies was achieved using the following gradient: A: 1 M (NH4)2SO4, 500 mM NaCl, 100 mM NaH2PO4 pH 7.4; B: 20 ​​mM NaH2PO4, 20% (v / v) isopropyl alcohol, pH 7.4. 0% B: 0-1 min, 0-95% B: 1-15 min, 95% B: 15-20 min, 95-0% B: 20-23 min, 0% B: 23-25 ​​min, with a flow rate of 700 μL / min. For each analysis, 15 μg of sample was loaded onto the column. UV chromatograms were recorded at 220 nm and 280 nm.

[0297] Charge variant analysis Measurements were performed on a Vanquish Flex UHPLC system (2.9) using a ProPac Elite WCX 5 μm 4 × 150 mm column (Thermo Fisher Scientific). Separation of antibody charge variants was performed with the following gradient: A: 1 × CX-1 buffer pH 5.6, B: 1 × CX-1 buffer pH 10.2 (Thermo Fisher Scientific). 0–100% B: 0–60 min, flow rate 1 ml / min. For each run, 24 μg of sample was loaded onto the column. UV chromatograms were recorded at 280 nm. Charge variant analysis was performed as previously described. Changes after 7 days of incubation at 40°C compared to day 0 are shown (% decrease in the main peak and % increase in acidic and basic species) (Figure 2).

[0298] SDS-PAGE Samples were prepared for SDS-PAGE by incubation (95°C, 5 min) in SDS sample buffer (BioRad) supplemented with 25 mM DTT and separated using 4–20% polyacrylamide gels (BioRad 4–20% Mini Protean TGX) followed by Coomassie staining (Imperial protein stain from Thermo Fisher Scientific).

[0299] ADC synthesis: General method for conjugating P5-based linker-payload constructs to antibodies to obtain DAR8. 50 μl of each anti-NaPi2b antibody (parent, AV15, AV18, AV21, AV25, AV29) at 10.0 mg / ml in P5-conjugation buffer (50 mM Tris, 1 mM EDTA, 100 mM NaCl, pH 8.3, room temperature) was mixed with 3.33 μl of a 10 mM TCEP solution in P5-conjugation buffer. Immediately after, 1.67 μl of a 40 mM solution of the P5-exatecan construct dissolved in DMSO was added. The mixture was shaken at 350 rpm at 25°C for 16 hours. The reaction mixture was purified by preparative size-exclusion chromatography using 25 ml of Superdex™ 200 Increase 10 / 300GL (Cytiva, Sweden) and eluted with sterile PBS (Merck, Germany) at a flow rate of 0.8 ml / min. Fractions containing the antibody were combined and concentrated by spin filtration (Amicon® Ultra-2 mL MWCO: 30 kDa, Merck, Germany).

[0300] Binding to human NaPi2B and rat NaPi2B assessed by flow cytometry HEK293 cells stably overexpressing human Napi2b and rat Napi2b were generated by stably integrating into the parent HEK293 cell line a full-length human or rat Napi2b-mCherry-(GGGS)3x-mCherry expression construct under the control of the human EF1 promoter and a puromycin selection cassette under the control of the CMV promoter. Briefly, cells were transfected with the linearized plasmid using Lipfectamine 2000 (Thermo Fisher) and selected with puromycin antibiotic. Cells were then single-cell cloned in 96-well plates by serial dilution under continuous antibiotic selection. Clones were screened for target expression by flow cytometry and for mCherry fluorescence by flow cytometry and fluorescence microscopy. Clones positive for target and mCherry were expanded and used for further experiments. The equilibrium binding constant (K D To determine the K (kJ / kcal), HEK293 cells stably expressing human (A and C), cynomolgus monkey (B), or rat (D) full-length NaPi2b-mCherry were incubated with antibody at concentrations ranging from 0.002 to 200 nM, stained with an Alexa dye-conjugated anti-human IgG H+L secondary antibody (Thermo Fisher Scientific), and analyzed by flow cytometry. Antibody binding was examined in mCherry-positive cells. Mean fluorescence intensity (MFI) ratios were normalized to the secondary antibody control. Assays were performed in duplicate, and data points were analyzed by nonlinear regression using a one-site-specific binding model and calculated using Prism 9 software. D The graph shows the mean (n=2) ± SEM (Figure 3).

[0301] Binding to immobilized human NaPi2B assessed by ELISA The binding of increasing concentrations of the parental and AV mAb clones to purified immobilized recombinant human Napi2b antigen was examined in an ELISA setting.

[0302] To measure binding of parental and AV mAb clones to Napi2b antigen, surface-treated flat-bottom 96-well plates (Nunclon, Thermo Fisher Scientific) were coated with 1 μg / mL of purified recombinant human Napi2b antigen, consisting of Napi2b extracellular loop 2 expressed as an Fc-fused-6His-tagged protein in Expi-HEK293 cells. After blocking with 2% bovine serum albumin (Carl Roth) in 1x PBS-Tween 20 (0.05%), increasing antibody concentrations (0.00015 μg / ml, 0.00046 μg / ml, 0.00137 μg / ml, 0.00412 μg / ml, 0.01235 μg / ml, 0.03704 μg / ml, 0.11111 μg / ml, 0.33333 μg / ml, 1.00000 μg / ml, 3.00000 μg / ml, and 9.00000 μg / ml) were allowed to bind for 2 hours at room temperature. Bound antibodies were detected by incubation with HRP-conjugated goat anti-human kappa light chain secondary antibody (diluted 1:10,000 in blocking solution) for 1 hour at room temperature. Ultra-TMB (Thermo Fisher, 34028) substrate was added and incubated at room temperature for 15–30 min, followed by the addition of 100 μl / well of 1 M sulfuric acid. Absorbance at 450 nm was measured within 10 min after acid addition using a microplate reader, Infinite M1000 Pro (Tecan). The apparent dissociation constant (K D ) was calculated by nonlinear regression using a one-site specific binding model using Prism 9 software. D The concentrations (unit: μg / ml) were 0.02209 (parent mAb), 0.01581 (AV15), 0.01494 (AV18), 0.01248 (AV21), 0.01060 (AV25), and 0.01238 (AV29). The graph shows the mean (n = 2) ± SEM (Figure 4).

[0303] Internalization assessed by flow cytometry To investigate internalization using pHrodo, a goat anti-human IgG Fcγ fragment-specific secondary antibody (Jackson ImmunoResearch) was labeled using the pHrodo™ Deep Red Antibody Labeling Kit (Thermo Fisher Scientific) according to the manufacturer's instructions. Napi2b-positive OVCAR-3 cells were incubated with 5 μg / ml of parental and AV mAb clones in the presence of equimolar amounts of pHrodo Deep Red-labeled secondary antibodies at 37°C for 1, 5, and 24 hours. An increase in MFI indicates the presence of AV antibodies in late endosomal and lysosomal compartments. The MFI ratio was calculated by dividing the MFI of cells incubated with pHrodo by the MFI of unstained cells (Figure 5).

[0304] Melting curves evaluated by NanoDSF The thermal stability of the protein was measured using nanodifferential scanning fluorimetry (nanoDSF), which measures the temperature-dependent change in the intrinsic fluorescence of tryptophan and tyrosine residues (Tycho NT.6, NanoTemper Technologies). For this, 1 μM of protein in PBS was absorbed into a capillary tube and subsequently placed in the reader. The intrinsic fluorescence of the protein was then measured at 330 nM and 350 nM during incubation at increasing temperatures. The change in the fluorescence signal indicates a transition in the folding state of the protein, and the temperature at which the transition occurs is called the inflection temperature (T i ) or melting temperature (T m ) (Haffke, M. et al., Label-free Thermal Unfolding Assay of G Protein-Coupled Receptors for Compound Screening and Buffer Composition Optimization. 2016) (Figure 6).

[0305] In vitro cytotoxicity assessed by resazurin assay To investigate the direct cytotoxicity of the ADCs, cells were seeded into 96-well plates (flat-bottom, 5000 cells / well, suspended in 100 μl of medium) and incubated with increasing concentrations of the ADCs (0–3 μg / ml) in medium for 7 days to generate dose-response curves. Prior to viability analysis, the supernatant over the adherent cells was removed and replaced with fresh medium. Cell death was then analyzed using resazurin (Sigma-Aldrich) as a cell viability dye at a final concentration of 55 μM. Fluorescence emission at 590 nM was measured using an Infinite M1000 Pro microplate reader (Tecan). Cell viability was determined by dividing the fluorescence of ADC-treated cells by the fluorescence from control cells similarly treated with medium alone. Graphs show mean values ​​(n = 2) ± SEM (Figure 7).

[0306] Bystander death To analyze the bystander activity of the ADC against target-negative cells, 20,000 NaPi2B-positive cells (OVCAR-3) were incubated with increasing concentrations of the ADC (0–3 μg / ml). After 5 days, half of the cell culture supernatant was transferred to 5,000 NaPi2B-negative cells (SW-620) and incubated for an additional 5 days. Killing was analyzed by viability assay using resazurin as previously described (Figure 8).

[0307] In vitro inhibition of topoisomerase I by ADC-mediated delivery of exatecan Inhibition of topoisomerase I by delivery of exatecan via the TUB-040 ADC induces DNA damage markers. OVCAR-3 cells were treated with 5 μg / mL TUB-040 or 5 nM free exatecan for 72 hours. Cells were stained with Live / Dead stain and for the DNA damage markers active caspase-3, cleaved PARP, and phosphorylated H2A.X (Ser-139) and analyzed by flow cytometry. Graphs show mean values ​​(n=2) ± SEM (Figure 9).

[0308] In vivo PK evaluation of one ADC In vivo PK studies were conducted using AV25 and AV25-P5(PEG24)-VC-PAB-exatecan. Female Sprague-Dawley rats were treated with 10 mg / kg of unconjugated AV25 antibody or ADC. Blood samples were collected after various time points, and ADC amounts were quantified using total antibody and intact ADC ELISA assays.

[0309] To evaluate the in vivo PK of the ADC, total antibody concentrations in the serum of ADC-treated SD rats were measured at various time points. All humanized anti-NaPi2B antibodies were analyzed in rat serum over a range of 2000–15.6 ng / ml. Nunc 96-well plates (100 μl / well) were coated with NaPi2B diluted in PBS (required concentration: 0.25 μg / ml) and sealed with PCR foil. The plates were incubated in a refrigerator at 2–8°C overnight. The coated plates were washed three times with 300 μl of PBST. 200 μl / well of blocking solution (2% albumin in PBST) was added, the plates were sealed, and the plates were incubated at room temperature for 1 hour. The coated plates were washed three times with 300 μl of PBST. 100 μl of the prepared standards (2000–15.6 ng / ml each of ADC, QC, and test samples) was added per well, the plate was sealed, and the plate was incubated at room temperature for 1 hour. The plate was washed three times with 300 μl of PBST. 100 μl / well of anti-human IgG (γ-chain specific)-peroxidase antibody (diluted 1:60,000 in PBS) was added and the plate was incubated at room temperature for 1 hour. The plate was washed three times with 300 μl of PBST. 50 μl / well of TMB was added, the plate was sealed, and the plate was incubated at room temperature for 15 minutes. 50 μl / well of 1 M sulfuric acid was added. The absorbance was measured at 450 nm using a Tecan plate reader.

[0310] To evaluate the in vivo stability of the ADC, the concentration of intact ADC in the serum of ADC-treated SD rats was measured at various time points. Intact ADC was analyzed in rat serum over a range of 2000–15.6 ng / ml. Nunc 96-well plates (100 μl / well) were coated with rabbit anti-exatecan mAb diluted in PBS (required concentration: 1 μg / ml) and sealed with PCR foil. The plates were incubated in a refrigerator at 2–8°C overnight. The coated plates were washed three times with 300 μl of PBST. 200 μl / well of blocking solution (2% albumin in PBST) was added, the plates were sealed, and the plates were incubated at room temperature for 1 hour. The coated plates were washed three times with 300 μl of PBST. 100 μl of the prepared standards (2000–15.6 ng / ml of each ADC, QC, and test sample) was added per well, the plate was sealed, and the plate was incubated at room temperature for 1 hour. The plate was washed three times with 300 μl of PBST. 100 μl / well of goat anti-human IgG (H+L) (pre-adsorbed) (diluted 1:25,000 in PBS) was added and the plate was incubated at room temperature for 1 hour. The plate was washed three times with 300 μl of PBST. 100 μl / well of TMB was added, the plate was sealed, and the plate was incubated at room temperature for 10 minutes. 100 μl / well of 1 M sulfuric acid was added. The absorbance was measured at 450 nm using a Tecan plate reader (Figure 10).

[0311] Linker-payload synthesis General Method 2 for the Synthesis of PEGylated P5 Building Blocks via the Staudinger Phosphonite Reaction TIFF2025536308000229.tif57148

[0312] A 25 mL Schlenk flask under argon atmosphere was charged with 267 mg of bis(diisopropylamino)chlorophosphine (1.00 mmol, 1.00 equiv.) and cooled to 0°C, and 2.20 mL of ethynylmagnesium bromide solution (0.5 M in THF, 1.10 mmol, 1.10 equiv.) was added dropwise. The yellowish solution was allowed to warm to room temperature and stirred for an additional 30 minutes. 3.00 mmol (3.0 equiv.) of the desired PEG alcohol dissolved in 5.56 mL of 1H-tetrazole solution (0.45 M in MeCN, 2.50 mmol, 2.50 equiv.) was added, and the white suspension was stirred overnight at room temperature. The formation of the desired phosphonite was confirmed by 31 The reaction mixture was monitored by P-NMR. 1.0 mmol (1.0 equiv.) of the desired azide dissolved in 2 mL of DMF, THF, or MeCN was added, and the suspension was further stirred at room temperature for 24 h. The crude reaction mixture was purified using preparative HPLC.

[0313] P5(PEG12)-OSu TIFF2025536308000230.tif27128

[0314] The title compound was synthesized according to General Method 2 from 19.5 mg of bis(diisopropylamino)chlorophosphine (73 μmol, 1.00 equiv.), 146 μL of ethynylmagnesium bromide solution (0.5 M in THF, 73 μmol, 1.00 equiv.), 100 mg of dodecaethylene glycol (183 μmol, 2.50 equiv.), 400 μL of 1H-tetrazole solution (0.45 M in MeCN, 183 μmol), and 19 mg of 4-azidobenzoic acid-N-hydroxysuccinimide ester (73 μmol, 1.00 equiv.). After preparative HPLC (Method D) and lyophilization, the product was obtained as a colorless oil (42.5 mg, 50 μmol, 68%). TIFF2025536308000231.tif52170

[0315] P5(PEG12)-COOH TIFF2025536308000232.tif25128

[0316] The title compound was synthesized according to general method 2 from 40 mg of bis(diisopropylamino)chlorophosphine (150 μmol, 1.00 equiv.), 360 μL of ethynylmagnesium bromide solution (0.5 M in THF, 180 μmol, 1.2 equiv.), 245 mg of PEG12 (450 μmol, 3.0 equiv.), 0.83 mL of 1H-tetrazole solution (0.45 M in MeCN, 450 μmol, 2.5 equiv.), and 39 mg of 4-azidobenzoic acid (150 μmol, 1.00 equiv.). After preparative HPLC (method D) and lyophilization, the product was obtained as a colorless oil (25 mg, 34 μmol, 23%). HR-MS results: C 33 H 57 NO 16 P + [M+H] + Theoretical value: 754.3410, measured value: 754.3398 (UV trace in Figure 11).

[0317] P5(PEG24)-OSu TIFF2025536308000233.tif27128

[0318] The title compound was synthesized according to General Method 2 from 41 mg of bis(diisopropylamino)chlorophosphine (159 μmol, 1.00 equiv.), 370 μL of ethynylmagnesium bromide solution (0.5 M in THF, 185 μmol, 1.2 equiv.), 450 mg of PEG24 (388 μmol, 2.50 equiv.), 1.02 mL of 1H-tetrazole solution (0.45 M in MeCN, 466 μmol, 3.0 equiv.), and 40 mg of 4-azidobenzoic acid N-hydroxysuccinimide ester (155 μmol, 1.00 equiv.). After preparative HPLC (Method D) and lyophilization, the product was obtained as a colorless oil (79 mg, 57 μmol, 37%). MS results: C 61 H 109 N2O 30 P 2+ [M+2H] 2+ Theoretical value: 690.3396, measured value: 690.81 (UV trace in Figure 12).

[0319] NH2-VC-PAB-exatecan TFA salt TIFF2025536308000234.tif53158

[0320] A screw-cap vial was charged with 34.3 mg of exatecan mesylate (0.0645 mmol, 1.0 equiv.) and suspended in 645 μL of dry DMSO. 241 μL (0.0967 mmol, 1.5 equiv.) of a 0.4 mol / L solution of Fmoc-VC-PAB-PNP in dry DMSO, 64.5 μL (0.0645 mmol, 1.0 equiv.) of a 1 mol / L solution of HOBt hydrate in dry DMSO, and 113 μL (0.645 mmol, 10.0 equiv.) of DIPEA were added. The yellow solution was stirred at 50°C for 2 hours. 425 μL of a 50% (w / w) solution of diethanolamine in dry DMSO was then added, and the reaction mixture was allowed to stir at room temperature for an additional 30 minutes. 1.5 ml of MeCN and 2.5 mL of HO were added and the yellow solution was directly purified by preparative HPLC using method D. After lyophilization, 47.3 mg (76.7%, 0.0495 mmol) of a yellowish solid was obtained as the TFA salt. HR-MS results: C 43 H 50 FN8O9 + [M+H] + Theoretical value: 841.3680, measured value: 841.3696 (UV trace in Figure 13).

[0321] NH2-VA-PAB-exatecan TFA salt TIFF2025536308000235.tif52157

[0322] A screw-cap vial was charged with 1.23 mg of exatecan mesylate (0.00232 mmol, 1.0 equiv.) and suspended in 23 μL of dry DMSO. 8.7 μL (0.00348 mmol, 1.5 equiv.) of a 0.4 mol / L solution of Fmoc-VA-PAB-PNP in dry DMSO, 2.3 μL (0.00232 mmol, 1.0 equiv.) of a 1 mol / L solution of HOBt hydrate in dry DMSO, and 4 μL (0.0232 mmol, 10.0 equiv.) of DIPEA were added. The yellow solution was stirred overnight at room temperature. 15 μL of a 50% (w / w) solution of diethanolamine in dry DMSO was then added, and the reaction mixture was allowed to stir at room temperature for an additional 30 minutes. 1.5 mL of MeCN and 2.5 mL of HO were added, and the yellow solution was directly purified by preparative HPLC using Method C. After lyophilization, 1.01 mg (50.0%, 0.00116 mmol) of a yellowish solid was obtained as the TFA salt. HR-MS results: C 40 H 44 FN6O8 + [M+H] + Theoretical value: 755.3200, measured value: 755.3201 (UV trace in Figure 14).

[0323] P5(PEG2)-VC-PAB-exatecan TIFF2025536308000236.tif53156

[0324] A screw-cap vial was charged with 23.4 μL (0.00468 mmol, 1.0 equiv.) of a 200 mM NH2-VC-PAB-exatecan TFA salt solution in dry DMSO, 46.8 μL (P5(PEG2)-COOSu, 0.00936 mmol, 2.0 equiv.) of a 200 mM 2-(2-hydroxyethoxy)ethyl-N-(4-benzoic acid-N-hydroxysuccinimide ester)-P-ethynylphosphonamidate solution, and 4.08 μL (0.0234 mmol, 5.0 equiv.) of DIPEA. The solution was shaken at 50 °C for 5 hours, allowed to cool to room temperature, 1.5 mL of MeCN and 2.5 mL of HO were added, and the solution was directly purified by preparative HPLC using Method C. After lyophilization, 1.33 mg (25.0%, 0.00117 mmol) of a yellowish solid was obtained. HR-MS results: C 56 H 64 FN9O 14 P + [M+H] + Theoretical value: 1136.4289, measured value: 1136.4306 (UV trace in Figure 15).

[0325] P5(PEG12)-VC-PAB-exatecan TIFF2025536308000237.tif53155

[0326] A screw-cap vial was charged with 51 μL (0.0102 mmol, 1.0 equiv.) of a 200 mM NH2-VC-PAB-exatecan TFA salt solution in dry DMSO, 102 μL (P5(PEG12)-COOH, 0.0204 mmol, 2.0 equiv.) of a 200 mM PEG12-N-(4-benzoic acid)-P-ethynylphosphonamidate solution in dry DMSO, 102 μL (0.0255 mmol, 2.5 equiv.) of a 250 mM Pybop solution in dry DMSO, and 8.89 μL (0.051 mmol, 5.0 equiv.) of DIPEA. The solution was shaken at room temperature for 2 hours, 1.5 mL of MeCN and 2.5 mL of HO were added, and the solution was directly purified by preparative HPLC using Method D. After lyophilization, 15.91 mg (99.0%, 0.0101 mmol) of a yellowish solid was obtained. HR-MS results: C 76 H 105 FN9O 24 P 2+ [M+H] 2+ Theoretical value: 788.8492, measured value: 788.8485 (UV trace in Figure 16).

[0327] P5(PEG24)-VC-PAB-exatecan TIFF2025536308000238.tif53156

[0328] A screw-cap vial was charged with 102 μL (0.0204 mmol, 1.0 equiv.) of a 200 mM NH-VC-PAB-exatecan TFA salt solution in dry DMSO, 204 μL of a 200 mM solution in dry DMSO (P5(PEG24)-OSu, 0.0408 mmol, 2.0 equiv.), and 17.78 μL (0.102 mmol, 5.0 equiv.) of DIPEA. The solution was shaken overnight at room temperature, 1.5 mL of MeCN and 2.5 mL of HO were added, and the solution was directly purified by preparative HPLC using Method D. After lyophilization, 25.76 mg (60.0%, 0.01224 mmol) of a yellowish solid was obtained. HR-MS results: C 100 H 153 FN9O 36 P2+ [M+H] 2+ Theoretical value: 1053.5081, measured value: 1053.50833 (UV trace in Figure 17).

[0329] P5(PEG12)-VA-PAB-exatecan TIFF2025536308000239.tif54158

[0330] A screw-cap vial was charged with 11.6 μL (0.00116 mmol, 1.0 equiv.) of a 100 mM NH2-VA-PAB-exatecan TFA salt solution in dry DMSO, 8.7 μL (P5(PEG12)-COOH, 0.00174 mmol, 1.5 equiv.) of a 200 mM PEG12-N-(4-benzoic acid)-P-ethynylphosphonamidate solution in dry DMSO, 11.6 μL (0.00232 mmol, 2.0 equiv.) of a 200 mM Pybop solution in dry DMSO, and 2.02 μL (0.0116 mmol, 10.0 equiv.) of DIPEA. The solution was shaken at room temperature for 2 hours, 1.5 mL of MeCN and 2.5 mL of HO were added, and the solution was directly purified by preparative HPLC using Method C. After lyophilization, 0.56 mg (32.2%, 0.000375 mmol) of a yellowish solid was obtained. HR-MS results: C 73 H 99 FN7O 23 P 2+ [M+H] 2+ Theoretical value: 745.8252, Measured value: 745.8255 (UV trace in Figure 18).

[0331] P5(PEG12)-exatecan TIFF2025536308000240.tif55133

[0332] A screw-cap vial was charged with 50 μL (0.005 mmol, 1.0 equiv.) of a 100 mM suspension of exatecan mesylate in dry DMSO, 20 μL (P5(PEG12)-COOH, 0.005 mmol, 1.0 equiv.) of a 250 mM solution of PEG12-N-(4-benzoic acid)-P-ethynylphosphonamidate in dry DMSO, 20 μL (0.006 mmol, 1.2 equiv.) of a 300 mM solution of Pybop in dry DMSO, and 4.33 μL (0.025 mmol, 5.0 equiv.) of DIPEA. The solution was shaken at room temperature for 2 hours, 1.5 mL of MeCN and 2.5 mL of HO were added, and the solution was directly purified by preparative HPLC using Method C. After lyophilization, 2.63 mg (45.0%, 0.0023 mmol) of a yellowish solid was obtained. HR-MS results: C 57 H 77 FN4O 19 P + [M+H] + Theoretical value: 1171.4899, measured value: 1171.4852 (UV trace in Figure 19).

[0333] mAb and ADC characterization Analytical summary of the synthesized mAb and ADC derived from P5(PEG24)-VC-PAB-exatecan (Figure 20). The percentage of HMWS was measured by analytical size exclusion chromatography as previously described. This percentage represents the area of ​​the peak with a shorter retention time compared to the monomeric species. Charge variant analysis was performed as previously described. Changes after 7 days of incubation at 40°C compared to day 0 are shown. ADC retention times were measured by hydrophobic interaction chromatography as previously described. Ti was determined from melting curves as measured by nanoDSF as previously described. Binding affinity was measured using flow cytometry (FACS) on OVCAR-3 cells or by ELISA on isolated proteins as previously described. Cytotoxicity was assessed by the resazurin assay as previously described. Internalization is shown as the percentage of the pHrodo MFI ratio after 5–6 h compared to time point 0, as previously described.

[0334] Analytical raw data for an exemplary monoclonal antibody (Figure 21). (A-D) Analytical characterization of one of the described mAbs. The antibody was expressed in Expi-CHO cells and purified by Protein A chromatography as previously described. The mAb was analyzed by HLPC-SEC (A), LC-MS (B), HLPC-HIC (C), and reducing SDS-PAGE (D).

[0335] LC / MS analysis of antibody clones Parent (Figure 22) Theoretical LC: 23473, Measured: 23472; Theoretical HC: 48705, Measured: 48706. AV15 (Figure 23) Theoretical LC: 23459, Measured: 23458; Theoretical HC: 48705, Measured: 48706. AV18 (Figure 24) Theoretical LC: 23473, Measured: 23472; Theoretical HC: 48632, Measured: 48634. AV21 (Figure 25) Theoretical LC: 23473, Measured: 23472; Theoretical HC: 48564, Measured: 48566. AV25 (Figure 26) Theoretical LC: 23443, Measured: 23442; Theoretical HC: 48632, Measured: 48634. AV29 (Figure 27) Theoretical LC: 23443, Measured: 23442; Theoretical HC: 48634, Measured: 48636.

[0336] Analytical Raw Data of Exemplary ADCs (Figure 28) Figure 28. (A-D) Analytical characterization of AV25-P5(PEG24)-VC-PAB-exatecan (DAR 8) synthesized and purified as previously described. A) Analytical size exclusion chromatography, B) LC-MS of the ADC preparation, C) Analytical hydrophobic interaction chromatography after conjugation. The data show that the ADC is fully conjugated up to DAR 8, with only small amounts of aggregates present after purification.

[0337] LC / MS analysis of ADCs Parent-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 29) Theoretical LC: 25579, Measured: 25577; Theoretical HC: 55023, Measured: 55021. AV15-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 30) Theoretical LC: 25565, Measured: 25563; Theoretical HC: 55023, Measured: 55022. AV18-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 31) Theoretical LC: 25579, Measured: 25577; Theoretical HC: 54950, Measured: 54947. AV21-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 32) Theoretical LC: 25579, Measured: 25577; Theoretical HC: 54882, Measured: 54881. AV25-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 33) Theoretical LC: 25549, Measured: 25547; Theoretical HC: 54950, Measured: 54950. AV29-P5(PEG24)-VC-PAB-exatecan DAR8 (Figure 34) Theoretical LC: 25549, Measured: 25547; Theoretical HC: 54952, Measured: 54950.

[0338] Example 2: Ex vivo serum stability, in vivo efficacy in cell line-derived xenograft models (CDX), and in vivo efficacy in patient-derived xenograft models (PDX) of exemplary ADCs of the invention: Ex vivo serum stability: Serum samples from each species were spiked with AV25-P5(PEG24)-VC-PAB-exatecan DAR 8 at a concentration of 0.2 mg / ml mixed into at least 80% of the serum. Samples were sterile filtered using UFC30GV0S centrifugal filter units (Merck, Germany) and incubated at 37°C for days 1, 2, 3, 5, and 7. Day 0 samples were processed further as is.

[0339] Recombinant NaPi2B antigen was coupled to Thermo NHS magnetic beads according to the manufacturer's instructions. The bead storage solution was removed from 40 μl of NaPi2B-coupled bead suspension. These beads were incubated with 100 μl of serum-ADC mixture premixed with 200 μl of PBS at room temperature for 2 hours. The supernatant was then removed, and the resin was washed twice with 1 mL of PBS-T. Subsequently, the resin was incubated with 10 μl of 100 mM glycine buffer (pH 2.5) at room temperature for 15 minutes. The solution was rebuffered to PBS using a 75 μL Zeba™ spin desalting column with a 7K MWCO (Thermo Fisher Scientific, USA). The sample was further processed for MS measurement as described above. The drug-to-antibody ratio (DAR) was calculated from the MS intensities of the light chain adducts conjugated to 0 or 1 molecule of P5(PEG24)-VC-PAB-exatecan and the MS intensities of the heavy chain adducts conjugated to 0 to 3 molecules of P5(PEG24)-VC-PAB-exatecan.

[0340] The results clearly demonstrate that the linker between the AV25 antibody and the exatecan drug molecule is highly stable in serum from different species, with no significant decrease in the amount of payload (no change in drug-to-antibody ratio (DAR)) even after incubating the ADC for several days (Figure 35).

[0341] In vivo efficacy of ADC in cell line-derived xenograft model (CDX): All animal experiments were performed in accordance with the German Animal Welfare Act and approved by the local authorities. 7 OVCAR-3 cells (100 μL + 100 μL Matrigel) were subcutaneously injected into CB17-Scid mice. Tumors grew to 0.1–0.15 cm on day 15 after implantation. 3 Treatment began when tumors reached a mean tumor volume of 100 mg / kg. After randomization into treatment and control groups, five animals per group were treated with either 1 mg / kg, 3 mg / kg, or 5 mg / kg of AV25-P5(PEG24)-VC-PAB-exatecan DAR 8, isotype-P5(PEG24)-VC-PAB-exatecan DAR 8, or vehicle as an intravenous injection once on day 0. Tumor volume, body weight, and general health were recorded throughout the study.

[0342] Complete tumor remission was observed after a single injection of the targeted AV25-P5(PEG24)-VC-PAB-exatecan DAR 8 at all dose levels (1 mg / kg, 3 mg / kg, and 5 mg / kg). In contrast, only a minimal effect was observed with the nontargeted isotype control, isotype-P5(PEG24)-VC-PAB-exatecan DAR 8 (...

Claims

1. an antibody drug conjugate (ADC) comprising an anti-NaPi2b antibody (e.g., an antibody against NPT2B_human sodium-dependent phosphate transport protein 2B (e.g., having UniProt accession number: O95436 or SEQ ID NO: 1) and / or an antibody against NPT2B_rat sodium-dependent phosphate transport protein 2B (e.g., having UniProt accession number: Q9JJ09 or SEQ ID NO: 2)), (a) the NaPi2b antibody is capable of binding to human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2), and preferably, the binding to the human Napi2b and the rat Napi2b has approximately the same K D and more preferably, the binding to the human Napi2b and the rat Napi2b is binding to endogenous Napi2b (e.g., located on the cell surface), and most preferably, the antibody is selected from the group consisting of AV-25 antibody, AV-15 antibody, AV-18 antibody, AV-21 antibody, and AV-29 antibody, and even most preferably, the approximately same K D has a difference of up to 50% (e.g., a difference of up to 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 7%, 5%, 4%, 3%, 2%, or 1%); (b) the NaPi2b antibody is capable of cross-reactivity with rat Napi2b (e.g., having UniProt Accession No.: Q9JJ09 or SEQ ID NO: 2), preferably via antigen-mediated antibody internalization, and more preferably, the internalization is improved (e.g., by at least 10%, e.g., 15%) compared to the corresponding internalization of a parent antibody (e.g., comprising SEQ ID NO: 54 and SEQ ID NO: 55, e.g., as shown in FIG. 1 ); (c) the NaPi2b antibody is capable of cross-reactivity with cynomolgus monkey (e.g., Macaca fascicularis) Napi2b (e.g., having UniProtKB Accession Number: A0A2K5UHY1 or SEQ ID NO: 3); (d) the NaPi2b antibody is capable of internalization, preferably by antigen-mediated antibody internalization; (e) The NaPi2b antibody comprises a heavy chain variable region (V H ) may have no dipeptide deamidation site within CDR2, and preferably, the absent dipeptide deamidation site is V H NG (Asn-Gly) in CDR2; wherein the anti-NaPi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) cytotoxic moieties (e.g., a cytotoxic payload, e.g., a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan), preferably via one or more linkers, more preferably via one or more phosphonamidate linkers, Antibody drug conjugates (ADCs).

2. The anti-NaPi2b antibody is a heavy chain variable region (V H ) does not have a dipeptide deamidation site in CDR2, and preferably, the non-existent dipeptide deamidation site is V H 2. The antibody drug conjugate (ADC) of any one of the preceding claims, wherein the CDR2 is NG (Asn-Gly).

3. 10. The antibody drug conjugate (ADC) of any one of the preceding claims, wherein the anti-NaPi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, even more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) camptothecin (e.g., exatecan) cytotoxic moieties, preferably via one or more linkers, more preferably via one or more phosphonamidate linkers.

4. 10. The antibody drug conjugate (ADC) of any one of the preceding claims, wherein the anti-NaPi2b antibody is conjugated to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, even more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably 8) exatecan cytotoxic moieties via one or more linkers, preferably via one or more phosphonamidate linkers.

5. The anti-NaPi2b antibody may be linked to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1-10, more preferably 2-10, most preferably 4-10, even most preferably 6-10, even most preferably 7-10, even most preferably 4 or 8, most preferably 8) camptothecin (e.g., exatecan) cytotoxic moieties (e.g., cytotoxic moieties).

10. The antibody drug conjugate (ADC) of any one of the preceding claims, wherein said antibody drug conjugates (ADCs) are conjugated via conjugation with ethynyl phosphonamidate linkers (e.g., to all eight interchain cysteine ​​residues), preferably wherein each phosphonamidate linker carries at least one PEG24 moiety (e.g., to prevent aggregation of the antibody drug conjugate (ADC)), and more preferably wherein the ADC carries up to eight of said linker payload moieties and eight PEG24 moieties.

6. an antibody drug conjugate (ADC) comprising a humanized monoclonal NaPi2b-specific IgG1 antibody conjugated to a cytotoxic payload; (a) the cytotoxic payload is selected from the group consisting of camptothecins, maytansinoids, calicheamicins, duocarmycins, tubulysins, amatoxins, dolastatins, and auristatins such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof; and / or (b) the cytotoxic payload is a camptothecin moiety C selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, ciratecan, cositecan, and gimatecan; and / or (c) the cytotoxic payload is conjugated via a cleavable linker (L), preferably the linker L is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction, more preferably the linker is cleavable by a protease, preferably a cathepsin such as cathepsin B; and / or (d) the linker L comprises a valine-citrulline-PAB moiety or a valine-alanine-PAB moiety; and / or (e) the cytotoxic payload is exatecan conjugated via a chemical valine-citrulline-PAB or valine-alanine-PAB releasing unit, wherein the releasing unit is cleavable by a protease; 10. The antibody drug conjugate (ADC) of any one of the preceding claims.

7. (a) the anti-NaPi2b monoclonal antibody can specifically recognize human Napi2b (e.g., SEQ ID NO: 1) and / or rat Napi2b (e.g., SEQ ID NO: 2) overexpressed in cancer cells; and (b) upon binding of an antibody drug conjugate (ADC) to NaPi2b overexpressed in cancer cells, the ADC can be internalized by the cells and transported into the lysosomal compartment, where preferably lysosomal proteases (e.g., cathepsin B) can liberate the cytotoxic payload from the ADC; 10. The antibody drug conjugate (ADC) of any one of the preceding claims.

8. The following features: (a) the antibody drug conjugate (ADC) is hydrophilic; (b) the ADC has a retention time of less than 10.12 minutes, preferably between about 9.73 minutes and about 10.06 minutes; (c) the ADC has an IC of less than 30 ng / mL, preferably less than 16.7 ng / mL (e.g., in OVCAR-3 cancer cells, e.g., HTB-161, ATCC). 50 More preferably, the IC 50 Cytotoxicity of approximately 13.0 to 15.5 ng / mL 10. The antibody drug conjugate (ADC) of any one of the preceding claims, comprising one or more of:

9. (a) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence having at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identity to SEQ ID NO: 4; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 5, Preferably, the anti-NaPi2b antibody is an AV25 antibody comprising a light chain comprising SEQ ID NO: 6 and a heavy chain comprising SEQ ID NO: 7; (b) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence having at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identity to SEQ ID NO: 8; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to IgG1A, IgG2A, IgG3A, IgG4B, IgG5B, IgG6A, IgG7B, IgG8B, IgG9A, IgG1B, IgG1C, IgG1D, IgG1E, IgG1F, IgG1H, IgG1H, IgG1I, IgG1I, IgG1I, IgG2F, IgG3H, IgG4I, IgG5I, IgG6A, IgG7B, IgG8A, IgG1F, IgG1H, IgG1I, IgG1F, IgG1I, IgG2F, IgG3H, IgG4I, IgG5I, IgG6A, IgG7B, IgG1F, IgG1H, IgG1F, IgG1I, IgG2F, IgG3H, IgG4I, IgG1F, IgG1H, IgG1F, IgG2F, IgG3H, IgG4I, IgG1F, IgG1H, IgG1F, IgG2F, IgG3H, IgG4I, IgG1F, IgG1H, IgG2F ... Preferably, the anti-NaPi2b antibody is an AV-15 antibody comprising a light chain comprising SEQ ID NO: 10 and a heavy chain comprising SEQ ID NO: 11; (c) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% identical (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) to SEQ ID NO: 12; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 13; Preferably, the anti-NaPi2b antibody is an AV-18 antibody comprising a light chain comprising SEQ ID NO: 14 and a heavy chain comprising SEQ ID NO: 15; (d) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence that is at least 80% identical (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) to SEQ ID NO: 16; and a light chain variable region having an amino acid sequence that is at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to SEQ ID NO: 17; Preferably, the anti-NaPi2b antibody is an AV-21 antibody comprising a light chain comprising SEQ ID NO: 18 and a heavy chain comprising SEQ ID NO: 19; (e) the anti-NaPi2b antibody comprises a heavy chain variable region having an amino acid sequence having at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identity to SEQ ID NO: 20; and a light chain variable region having an amino acid sequence that has at least 80% (e.g., at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identity to SEQ ID NO: 21; Preferably, the anti-NaPi2b antibody is an AV-29 antibody comprising a light chain comprising SEQ ID NO: 22 and a heavy chain comprising SEQ ID NO:

23.

10. The antibody drug conjugate (ADC) of any one of the preceding claims.

10. (a) the anti-NaPi2b antibody comprises a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 25, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 26, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 27, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 28, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 29; (b) the anti-NaPi2b antibody comprises a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 31, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 32, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 33, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 34, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 35; (c) the anti-NaPi2b antibody comprises a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 36, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 37, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 38, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 39, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 40, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 41; (d) the anti-NaPi2b antibody comprises a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 42, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 43, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 44, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 45, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 46, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 47; (e) the anti-NaPi2b antibody comprises a heavy chain variable region comprising a heavy chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 48, a heavy chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 49, and a heavy chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 50, and a light chain variable region comprising a light chain CDR1 having the amino acid sequence set forth in SEQ ID NO: 51, a light chain CDR2 having the amino acid sequence set forth in SEQ ID NO: 52, and a light chain CDR3 having the amino acid sequence set forth in SEQ ID NO: 53; 10. The antibody drug conjugate (ADC) of any one of the preceding claims.

11. Anti-NaPi2b antibodies have the following characteristics: (a) Monoclonal antibodies; (b) chimeric and / or humanized antibodies; (c) specific recognition of Napi2b, which is overexpressed in cancer cells; (d) a human IgG antibody, preferably a human IgG1 antibody; (e) containing kappa (κ) light chains; (f) containing lambda (λ) light chains; (g) containing an Fc-silencing mutation, such as a leucine (L) to alanine (A) substitution at positions 234 and 235 (LALA mutation); (wherein the LALA mutation can reduce the effector function of immune cells); (h) capable of being internalized by target cells (e.g., cancer cells) that express Napi2b (Preferably, the internalized antibody is directed to the lysosome); (i) Tumor-selective antibodies (preferably, the tumor is a liquid tumor and / or a solid tumor); (j) malignant cell-selective antibodies; (k) binding to human Napi2b and / or rat Napi2b in a glycosylation-dependent manner (wherein the antibody binds to a glycosylated form of the Napi2b protein); (l) a K of about 0.01 to about 10 nmol / L, preferably about 1 to about 10 nmol / L, more preferably about 1 to about 7 nmol / L, and even more preferably about 1 to about 4 nmol / L, relative to endogenously expressed human Napi2b (e.g., in OVCAR-3 cells (e.g., HTB-161, ATCC) that endogenously express Napi2b). D Having (More preferably, the K D is measured by FACS assay), Even most preferably, the K ranges from about 2.661 to about 6.644 nmol / L. D having; (m) optionally, a K in the range of about 0.01 to about 10 nmol / L for immobilized exogenous full-length Napi2b and / or one or more fragments thereof; D Having (Preferably, the one or more fragments comprise at least one extracellular domain (ECD) of the Napi2b (e.g., the ECD comprising amino acids 122-135 and / or amino acids 235-361 and / or amino acids 429-485 and / or amino acids 547-552 of human Napi2b having SEQ ID NO: 1) and / or one or more fragments of the ECD (e.g., having a length of about 15 to about 30 amino acids), wherein the full-length Napi2b and / or the one or more fragments thereof are fused or unfused to one or more protein tags (e.g., 6xHis tag, FLAG, HA, V5, Fc fusion, MBP, SUMO, TEV, GFP, TST), and preferably the K D is measured by ELISA assay and is preferably about 0.05 to about 0.2 nmol / L), More preferably, the K ranges from about 0.071 to about 0.147 nmol / L. D having; (n) cross-reactivity with rat Napi2b (e.g., having UniProt accession number: Q9JJ09 or SEQ ID NO: 2); and / or (m) heavy chain variable region (V H ) does not have a dipeptide deamidation site within CDR2 (Preferably, the absent dipeptide deamidation site is V H NG (Asn-Gly) in CDR2) 10. The antibody drug conjugate (ADC) of any one of the preceding claims, comprising one or more of:

12. Formula (I): or a pharmaceutically acceptable salt or solvate thereof, During the ceremony, The Ab is an anti-Na2Pi2b antibody according to any one of the preceding claims; is a double bond, or is a single bond; is a double bond, V is absent, or is a single bond, V is H or (C 1 ~C 8 ) alkyl; is a double bond, X is R 3 -C, or If is a single bond, then X is and; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20; An antibody drug conjugate (ADC) according to any one of claims 1 to 11, in particular according to claim 1.

13. is a double bond; V is absent; X is R 3 -C; and R 3 is H or an optionally substituted aliphatic residue or an optionally substituted aromatic residue; preferably, R 3 However, H or (C 1 ~C 8 ) alkyl; more preferably, R 3 13. The antibody drug conjugate (ADC) of claim 12, wherein

14. 14. The antibody drug conjugate (ADC) of claim 12 or 13, wherein Y is NH.

15. 15. The antibody drug conjugate (ADC) of any one of claims 12 to 14, wherein the connector unit CU is cleavable.

16. 16. The antibody drug conjugate (ADC) of claim 15, wherein the connector unit CU is cleavable by a protease, glucuronidase, sulfatase, phosphatase, esterase, or by disulfide reduction.

17. 17. The antibody drug conjugate (ADC) of claim 16, wherein the connector unit CU is cleavable by a protease, preferably a cathepsin, such as cathepsin B.

18. 18. The antibody drug conjugate (ADC) of any one of claims 12 to 17, wherein the connector unit CU comprises a valine-citrulline moiety or a valine-alanine moiety.

19. The connector unit CU is and where # indicates the point of attachment to Y; * indicates the point of attachment to the cytotoxic moiety CM, 19. The antibody drug conjugate (ADC) of claim 18.

20. The connector unit CU is and During the ceremony, * indicates the point of attachment to Y and ## indicates the point of attachment to the cytotoxic moiety CM; 19. The antibody drug conjugate (ADC) of claim 18.

21. R 1 but, and During the ceremony, indicates the position of O; K F -H, -PO 3 H, -(C 1 ~C 10 ) alkyl, -(C 1 ~C 10 )Alkyl-SO 3 H, -(C 2 ~C 10 )Alkyl-CO 2 H, -(C 2 ~C 10 ) alkyl-OH, -(C 2 ~C 10 )Alkyl-NH 2 , -(C 2 ~C 10 ) alkyl-NH(C 1 ~C 3 ) alkyl, and -(C 2 ~C 10 ) alkyl-N((C 1 ~C 3 )Alkyl) 2 and o is an integer ranging from 1 to 100; 21. The antibody drug conjugate (ADC) of any one of claims 12 to 20.

22. K F 22. The antibody drug conjugate (ADC) of claim 21, wherein

23. 23. The antibody drug conjugate (ADC) of claim 21 or 22, wherein o is in the range of 8 to 30.

24. 24. The antibody drug conjugate (ADC) of claim 23, wherein o is in the range of 20 to 28.

25. 25. The antibody drug conjugate (ADC) of claim 24, wherein o is 22, 23, 24, 25, or 26.

26. 24. The antibody drug conjugate (ADC) of claim 23, wherein o is in the range of 8 to 16.

27. 27. The antibody drug conjugate (ADC) of claim 26, wherein o is 10, 11, 12, 13, or 14.

28. 28. The antibody drug conjugate (ADC) of any one of claims 12 to 27, wherein the cytotoxic moiety CM is selected from the group consisting of camptothecins, maytansinoids, calicheamicins, duocarmycins, tubulysins, amatoxins, dolastatins, and auristatins such as monomethylauristatin E (MMAE), pyrrolobenzodiazepine dimers, indolino-benzodiazepine dimers, radioisotopes, therapeutic proteins and peptides (or fragments thereof), nucleic acids, PROTACs, kinase inhibitors, MEK inhibitors, KSP inhibitors, and analogs or prodrugs thereof.

29. 29. The antibody drug conjugate (ADC) of claim 28, wherein the cytotoxic moiety CM is a camptothecin moiety.

30. 30. The antibody drug conjugate (ADC) of claim 29, wherein the camptothecin moiety is selected from the group consisting of exatecan, DXD, SN38, camptothecin, topotecan, irinotecan, belotecan, lurtotecan, rubitecan, ciratecan, cositecan, and gimatecan.

31. The cytotoxic moiety CM has the formula:

31. The antibody drug conjugate (ADC) of claim 30, wherein the ADC is exatecan having the formula:

32. The cytotoxic moiety CM has the formula:

32. The antibody drug conjugate (ADC) of claim 31, which is exatecan having the formula:

33. 33. The antibody drug conjugate (ADC) of claim 31 or 32, wherein exatecan is attached to the connector unit CU via an amino group.

34. The Ab is an anti-NaPi2b antibody according to any one of the preceding claims; is a double bond, or is a single bond; is a double bond, V is absent, or is a single bond, then V is H; is a double bond, X is R 3 -C, or is a single bond, X is and; Y is NH; R 1 But the structure: and a polyethylene glycol unit having the formula: During the ceremony, indicates the position of O, K F is H, and o is an integer ranging from 8 to 30; R 3 is H; R 4 is H; CU has the following structure: where # indicates the point of attachment to Y; * indicates the point of attachment to the camptothecin moiety (CM); CM is a camptothecin moiety; m is 1; and n is an integer ranging from 1 to 10; 34. The antibody drug conjugate (ADC) of any one of claims 28 to 33.

35. is a double bond, V is absent, and X is R 3 -C and R 3 is H.

36. The camptothecin moiety CM has the formula:

36. The antibody drug conjugate (ADC) of claim 34 or 35, which is exatecan having the formula:

37. 37. The antibody drug conjugate (ADC) of claim 36, wherein exatecan is attached to the connector unit CU via an amino group.

38. 38. The antibody drug conjugate (ADC) of claim 37, wherein o is in the range of 20 to 28.

39. 39. The antibody drug conjugate (ADC) of claim 38, wherein o is 22, 23, 24, 25, or 26.

40. 40. The antibody drug conjugate (ADC) of any one of claims 34 to 39, wherein n is in the range of 2 to 10, preferably n is 4 or 8.

41. Formula (Ia): wherein Ab is an anti-NaPi2b antibody according to any one of the preceding claims.

41. The antibody drug conjugate (ADC) of claim 40.

42. 29. The antibody drug conjugate (ADC) of claim 28, wherein the cytotoxic moiety CM is an auristatin.

43. 43. The antibody drug conjugate (ADC) of claim 42, wherein the cytotoxic moiety is monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF).

44. 44. The antibody drug conjugate (ADC) of claim 43, wherein the cytotoxic moiety is monomethyl auristatin (MMAE).

45. conjugating the antibody of any one of the preceding claims to one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably 1 to 10, even more preferably 2 to 10, most preferably 4 to 10, even most preferably 6 to 10, even most preferably 7 to 10, even most preferably 4 or 8, most preferably 8) cytotoxic moieties (e.g., a cytotoxic payload, such as a tubulin inhibitor, e.g., a topoisomerase I inhibitor, e.g., an auristatin or camptothecin, e.g., MMAE (monomethylauristatin E) or MMAF (monomethylauristatin F), e.g., exatecan), preferably via one or more linkers, more preferably via one or more phosphonamidate linkers. A method for producing an antibody drug conjugate (ADC), comprising:

46. Formula (II) (In the formula, is a triple bond, or is a double bond; is a triple bond, V is absent, or is a double bond, V is H or (C 1 ~C 8 ) alkyl; is a triple bond, X is R 3 -C, or is a double bond, X is and; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; and m is an integer ranging from 1 to 10. or a pharmaceutically acceptable salt or solvate thereof, Formula (III): wherein Ab is an anti-NaPi2b antibody according to any one of the preceding claims; and n is an integer ranging from 1 to 20. of thiol-containing molecules and reacting the compound with As a result, the compound of formula (I) (In the formula, The Ab is an anti-NaPi2b antibody according to any one of the preceding claims; In the compound of formula (II) is a triple bond, is a double bond, or In the compound of formula (II) is a double bond, is a single bond; is a double bond, V is absent, or is a single bond, V is H or (C 1 ~C 8 ) alkyl; is a double bond, X is R 3 -C, or is a single bond, X is and; Y is NR 5 , S, O, or CR 6 R 7 and; R 1 is an optionally substituted aliphatic residue or an optionally substituted aromatic residue; R 3 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 4 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 5 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 6 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; R 7 is H or an optionally substituted aliphatic or an optionally substituted aromatic residue; CU is the connector unit; CM is a cytotoxic moiety; m is an integer ranging from 1 to 10; and n is an integer ranging from 1 to 20. or a pharmaceutically acceptable salt or solvate thereof.

46. ​​The method of claim 45, comprising:

47. reducing at least one disulfide bridge of the antibody in the presence of a reducing agent to form a thiol group (SH); 47. The method of claim 46, further comprising:

48. An antibody drug conjugate (ADC) produced by the method of any one of the preceding claims.

49. 10. A composition or kit comprising the antibody drug conjugate (ADC) of any one of the preceding claims.

50. 10. The composition according to any one of the preceding claims, which is a pharmaceutical and / or diagnostic composition.

51. 1. A method for the treatment, amelioration, prevention, and / or diagnosis of cancer, comprising: Preferably, the cancer is a solid cancer and / or a metastatic cancer, and more preferably, the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, and fallopian tube cancer; The method comprises administering a therapeutically or prophylactically effective amount of an antibody drug conjugate (ADC), composition, or kit of any preceding claim. The method.

52. 10. The antibody drug conjugate (ADC), composition or kit of any one of the preceding claims for use as a medicament and / or in therapy.

53. The following methods: (a) a method for the treatment, amelioration, prevention, and / or diagnosis of cancer, wherein preferably the cancer is a solid cancer and / or a metastatic cancer, and more preferably the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, and fallopian tube cancer; (b) methods for monitoring cancer progression and / or assessing the effectiveness of cancer treatments; (c) a method for screening candidate compounds for anti-cancer activity; (d) methods for altering the resistance of cancer cells to chemotherapy; (e) methods for sensitizing cancer cells to chemotherapy; (f) a method for inhibiting the proliferation of cancer cells expressing NaPi2b; (g) methods for producing or preparing antibodies; (h) methods for immunizing non-human animals; (i) methods for the preparation of hybridomas; (j) a method according to any preceding claim; (k) any one of methods (a) to (j), which is an in vivo, in vitro, or ex vivo method; 10. The antibody drug conjugate (ADC), composition, or kit of any preceding claim for use in one or more of the following:

54. below: (a) the treatment, amelioration, prevention, and / or diagnosis of cancer (Preferably, the cancer is a solid cancer and / or a metastatic cancer, and more preferably, the cancer is selected from the group consisting of lung cancer, ovarian cancer, thyroid cancer, non-squamous non-small cell lung cancer, non-mucinous ovarian cancer, papillary thyroid cancer, kidney cancer, endometrial cancer, uterine cancer, ureter cancer, bladder cancer, and fallopian tube cancer); (b) monitoring the progression of cancer and / or assessing the effectiveness of cancer treatments; (c) screening candidate compounds for anticancer activity; (d) altering the resistance of cancer cells to chemotherapy; (e) sensitizing cancer cells to chemotherapy; (f) inhibiting the proliferation of cancer cells expressing NaPi2b; (g) production or preparation of antibodies; (h) immunizing a non-human animal; (i) Preparation of hybridomas; (j) in the method of any preceding claim; (k) Use of any one of (a) to (j), which is an in vivo, in vitro, or ex vivo use.

4. Use of the antibody drug conjugate (ADC), composition, or kit of any preceding claim for one or more of the following:

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