Immunoconjugates targeting cd46 and methods of use thereof

Abstract

Disclosed herein are immunoconjugates comprising a CD46 binding domain and an effector agent. Also provided herein are methods of treating cancer comprising administering to a subject having cancer a pharmaceutical composition comprising an immunoconjugate comprising a CD46 binding domain and an effector agent. In one embodiment, the immunoconjugate is FOR46, which is a conjugate of the anti-CD46 antibody YS5FL linked to monomethyl auristatin E (MMAE) via a maleimidocaproyl-valine-citrulline-para-aminobenzoxycarbonyl (mc-vc-PAB) linker.

Description

[0001] CROSS-REFERENCE

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 062,740, filed August 7, 2020; which is incorporated by reference herein in its entirety. BACKGROUND

[0003] CD46, also known as CD46 complement regulatory protein, cluster of differentiation 46, and membrane cofactor protein, is an inhibitory complement receptor. Overexpression of CD46 has been observed in several cancers, such as breast cancer, colorectal cancer, liver cancer, lung cancer, or prostate cancer. In some cases, overexpression of CD46 is characterized as a negative prognostic factor. For example, in breast cancer patients and ovarian cancer patients, overexpression of CD46 is associated with shorter progression-free time and shorter overall survival time. There is a need for new therapies and treatment regimens targeting CD46 for the treatment of cancer. SUMMARY

[0004] The present disclosure provides immunoconjugates for the treatment of conditions characterized by cell surface CD46 expression, such as metastatic castration-resistant prostate cancer and multiple myeloma.

[0005] In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 1.0 to about 4.5 mg / kg, about 1.0 to about 4.0 mg / kg, about 1.0 to about 3.5 mg / kg, 1.0 to about 3.0 mg / kg, about 1.0 to about 2.57 mg / kg, about 1.0 to about 2.5 mg / kg, about 1.0 to about 2.4 mg / kg, about 1.5 to about 4.5 mg / kg, about 1.5 to about 4.0 mg / kg, about 1.5 to about 3.5 mg / kg, about 1.5 to about 3.0 mg / kg, about 1.50 to about 2.57 mg / kg, about 1.5 to about 2.5 mg / kg, about 1.5 to 2.4 mg / kg, about 1.5 to 2.0 mg / kg, about 1.8 to about 4.5 mg / kg, about 1.8 to about 4.0 mg / kg, about 1.8 to about 3.5 mg / kg, about 1.8 to about 3.0 mg / kg, about 1.8 to about 2.5 or about 7 mg / kg, about 1.8 to 2.0 about 2.5 mg / kg, about 1.8 mg / kg to about 2.4 mg / kg, or about 1.8 to about 2.0 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 1.5 to about 2.5 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, or about 4.0 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 1.8, about 2.4, or about 3.2 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 1.8 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 2.4 mg / kg. In some embodiments, the immunoconjugate is administered to the human subject at a dose of about 3.2 mg / kg.

[0006] In some embodiments, the immunoconjugate is administered to the human subject via intravenous infusion. In some embodiments, the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, the immunoconjugate is administered to the human subject every 21 days.

[0007] In some embodiments, the recombinant antibody is conjugated to an effector agent, wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, the effector agent comprises a drug. In some embodiments, the drug is an anti-cancer drug. In some embodiments, the drug is a chemotherapeutic agent. In some embodiments, the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, the drug is a microtubule inhibitor. In some embodiments, the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansinoid (or a derivative thereof). In some embodiments, the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the microtubule inhibitor is monomethyl auristatin E (MMAE).

[0008] In some embodiments, the ratio of the effector agent to the recombinant antibody is about 3 to about 5. In some embodiments, the ratio of the effector agent to the recombinant antibody is about 4.

[0009] In some embodiments, the effector agent is conjugated to the recombinant antibody via a linker. In some embodiments, the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyloxy carbonyl (mc-vc-PAB).

[0010] In some embodiments, the cancer is prostate cancer. In some embodiments, the prostate cancer is castration-resistant prostate cancer. In some embodiments, the cancer is multiple myeloma. In some embodiments, the multiple myeloma is relapsed or refractory multiple myeloma.

[0011] In some embodiments, the immunoconjugate binds to CD46 expressed on the surface of a cell and is internalized into the cell. In some embodiments, the immunoconjugate is internalized into the cell via macropinocytosis.

[0012] In another aspect, the present disclosure provides a method of treating cancer in a human subject in need thereof, the method comprising administering to the subject an immunoconjugate comprising: (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; and (b) monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine- citrulline-p-aminobenzoxycarbonyl (mc-vc-PAB) linker; wherein the immunoconjugate is administered at a dose of about 1.0 to about 4.0 mg / kg.

[0013] In another aspect, the present disclosure provides a pharmaceutical composition comprising (a) an immunoconjugate at a concentration of about 10.0 ± 5.0 mg / mL, and (b) histidine buffer; and wherein the immunoconjugate comprises: (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; and (b) an effector agent conjugated to the recombinant antibody.

[0014] In some embodiments, the pharmaceutical composition comprises about 10 mM to about 30 mM histidine buffer. In some embodiments, the pharmaceutical composition comprises about 10 mM to about 20 mM histidine buffer. In some embodiments, the pharmaceutical composition further comprises a cryoprotectant. In some embodiments, the cryoprotectant is a sugar. In some embodiments, sucrose or trehalose. In some embodiments, the pharmaceutical composition further comprises a stabilizer. In some embodiments, the stabilizer prevents denaturation of the recombinant antibody, prevents aggregation of the immunoconjugate, or both. In some embodiments, the stabilizer is a polysorbate. In some embodiments, the stabilizer is polysorbate 80. In some embodiments, the pH of the pharmaceutical composition is about 5.0 to about 7.0.

[0015] In some embodiments, the stabilizer is a polymer. In some embodiments, the polymer is a synthetic or semi-synthetic polymer. The polymer can be a linear polymer, such as povidone or polyvinyl alcohol. The polymer can be a copolymer, such as a PVA-PEG graft copolymer. The polymer can be ionic, such as sodium carboxymethylcellulose, sodium alginate, chitosan, or polyethylene glycol. The semi-synthetic polymer can be a non-ionic polymer, such as HPMC, HPC, or HEC. In some embodiments, the stabilizer is a surfactant. The surfactant can be an ionic surfactant, such as sodium docusate, sodium dodecyl sulfate, or polyethylenimine, or a non-ionic surfactant, such as Tween, poloxamer, D-a-tocopherol, polyethylene glycol succinate, a block copolymer of polyethylene oxide-polyethylene oxide-polyethylene oxide. In some embodiments, the stabilizer is a food protein, an amino acid, or a copolymer. In some embodiments, the stabilizer is Captisol, Monosteol, microcrystalline cellulose and carboxymethylcellulose, sorbitol, or a cellulose gel.

[0016] In some embodiments, the pharmaceutical composition comprises a buffering agent. The buffering agent can be selected from acetate, citrate, tartrate, histidine, glutamate, phosphate, Tris, glycine, bicarbonate, succinate, sulfate, or nitrate. In some embodiments, the pharmaceutical composition comprises a tonicity adjusting agent. The tonicity adjusting agent can be selected from mannitol, sorbitol, lactose, dextrose, trehalose, sodium chloride, potassium chloride, glycerol, and glycerin. In some embodiments, the pharmaceutical composition comprises a bulking agent. The bulking agent can be a sugar or polyol selected from sucrose, trehalose, glucose, lactose, sorbitol, mannitol, and glycerol. The bulking agent can be an amino acid selected from arginine, aspartic acid, glutamic acid, lysine, proline, glycine, histidine, methionine, and alanine. The bulking agent can be a polymer or protein selected from gelatin, PVP, PLGA, PEG, dextran, cyclodextrin and derivatives, starch derivatives, HSA, and BSA. In some embodiments, the pharmaceutical composition comprises an antioxidant. The antioxidant can be selected from histamine, methionine, ascorbic acid, glutathione, vitamin E, or polyethyleneimine. In some embodiments, the pharmaceutical composition comprises an antimicrobial preservative. The pharmaceutical preservative can be selected from benzyl alcohol, m-cresol, phenol, and 2-phenoxyethanol. In some embodiments, the pharmaceutical composition can comprise a chelating agent and / or complexing agent. The chelating agent can be disodium ethylenediaminetetraacetate, diethylenetriaminepentaacetic acid, citric acid, hexaphosphate, mercaptoacetic acid, or zinc.

[0017] In some embodiments, the recombinant antibody is conjugated to an effector agent, wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, the effector comprises a drug. In some embodiments, the drug is an anticancer drug. In some embodiments, the drug is a chemotherapeutic agent. In some embodiments, the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, the drug is a microtubule inhibitor. In some embodiments, the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansine (or a derivative thereof). In some embodiments, the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the microtubule inhibitor is monomethyl auristatin E (MMAE). In some embodiments, the ratio of the effector agent to the recombinant antibody in the population of immunoconjugates is about 3 to about 5. In some embodiments, the ratio of the effector agent to the recombinant antibody in the population of immunoconjugates is about 4.

[0018] In some embodiments, the effector agent is conjugated to the recombinant antibody via a linker. In some embodiments, the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyloxycarbonyl (mc-vc-PAB).

[0019] In another aspect, the present disclosure provides a pharmaceutical composition comprising an immunoconjugate at a concentration of about 10.0 ± 1.0 mg / mL, about 20 mM histidine buffer, about 8.0% sucrose, about 0.01% polysorbate 80; and wherein the immunoconjugate comprises: (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; (b) monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine-citrulline-para-aminobenzyloxycarbonyl (mc-vc-PAB) linker.

[0020] In another aspect, the present disclosure provides a method of treating relapsed or refractory multiple myeloma (RRMM) in a human subject in need thereof, the method comprising administering to the subject a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, each with 0 to 3 amino acid modifications, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, each with 0 to 3 amino acid modifications.

[0021] In another aspect, the present disclosure provides a method of treating relapsed or refractory multiple myeloma (RRMM) in a human subject in need thereof, the method comprising administering to the subject a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively.

[0022] In another aspect, the present disclosure provides a method of treating metastatic castration-resistant prostate cancer in a human subject in need thereof, the method comprising administering to the subject a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, each with 0 to 3 amino acid modifications, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, each with 0 to 3 amino acid modifications.

[0023] In another aspect, the present disclosure provides a method of treating metastatic castration-resistant prostate cancer in a human subject in need thereof, the method comprising administering to the subject a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively.

[0024] In some embodiments, the recombinant antibody of the method for treating relapsed or refractory multiple myeloma or castration-resistant prostate cancer is conjugated to an effector agent, wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, the effector comprises a drug. In some embodiments, the drug is an anticancer drug. In some embodiments, the drug is a chemotherapeutic agent. In some embodiments, the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, the drug is a microtubule inhibitor. In some embodiments, the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansine (or a derivative thereof). In some embodiments, the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the microtubule inhibitor is monomethyl auristatin E (MMAE). In some embodiments, the ratio of the effector agent to the recombinant antibody is about 3 to about 5. In some embodiments, the ratio of the effector agent to the recombinant antibody is about 4.

[0025] In some embodiments, the effector agent of the method for treating relapsed or refractory multiple myeloma or castration-resistant prostate cancer is conjugated to the recombinant antibody via a linker. In some embodiments, the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyloxy carbonyl (mc-vc-PAB).

[0026] In some embodiments, the recombinant antibody of the methods for treating relapsed or refractory multiple myeloma or castration-resistant prostate cancer is administered at a dose of about 1.0 to about 4.5 mg / kg, about 1.0 to about 4.0 mg / kg, about 1.0 to about 3.5 mg / kg, about 1.0 to about 3.0 mg / kg, about 1.0 to about 2.7 mg / kg, about 1.0 to about 2.5 mg / kg, about 1.0 to 2.4 mg / kg, 1.5 to about 4.5 mg / kg, 1.5 to about 4.0 mg / kg, 1.5 to about 3.5 mg / kg, 1.5 to about 3.0 mg / kg, about 1.5 to 2, about 2.7 mg / kg, about 1.5 mg / kg, 1 to about 2.5 mg / kg, about 1.5 to about 2.4 mg / kg, about 1.5 to about 2.0 mg / kg, about 1.8 to about 4.5 mg / kg, about 1.8 to about 4.0 mg / kg, about 1.8 to about 3.5 mg / kg, about 1.8 to about 3.0 mg / kg, about 1.8 to about 2.5 or 7 mg / kg, about 1.8 to 2.0, about 2.5 mg / kg, about 1.8 to about 2.4 mg / kg, or about 1.8 to about 2.0 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 1.5 to about 2.5 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, or about 4.0 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 1.8, about 2.4, or about 3.2 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 1.8 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 2.4 mg / kg. In some embodiments, the recombinant antibody is administered at a dose of about 3.2 mg / kg.

[0027] In some embodiments, the recombinant antibody of the methods for treating relapsed or refractory multiple myeloma or castration-resistant prostate cancer is administered to the human subject via intravenous infusion. In some embodiments, the recombinant antibody is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, every 28 days, or monthly. In some embodiments, the recombinant antibody is administered to the human subject every 21 days.

[0028] In another aspect, the present disclosure provides a method of treating relapsed or refractory multiple myeloma (RRMM) in a human subject in need thereof, the method comprising administering to the subject an immunoconjugate, wherein the immunoconjugate comprises (i) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; conjugated via a linker to (ii) monomethyl auristatin E (MMAE), wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyl oxycarbonyl (mc-vc-PAB).

[0029] In another aspect, the present disclosure provides an immunoconjugate comprising: a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of adducts; wherein each adduct of the one, two, three, or four pairs of adducts comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine-citrulline-para-aminobenzyl oxycarbonyl (mc-vc-PAB) linker; wherein each pair of the one, two, three, or four pairs of adducts is conjugated to a pair of cysteine residues of the recombinant antibody, wherein the pair of cysteine residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain. In some embodiments, the immunoconjugate comprises two pairs of the adducts.

[0030] In another aspect, the present disclosure provides a pharmaceutical composition comprising an immunoconjugate at a concentration of about 10.0 ± 1.0 mg / mL, about 20 mM histidine buffer at pH 6.0, about 8.0% sucrose, and about 0.01% polysorbate 80, the immunoconjugate comprising: a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of payloads; wherein each payload of the one, two, three, or four pairs of payloads comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine- citrulline-p-aminobenzyloxycarbonyl (mc-vc-PAB) linker; wherein each pair of the one, two, three, or four pairs of payloads is conjugated to a pair of cysteine residues of the recombinant antibody, wherein the pair of cysteine residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain.

[0031] In another aspect, the present disclosure provides a pharmaceutical composition comprising an immunoconjugate at a concentration of about 10.0 ± 1.0 mg / mL, about 20 mM histidine buffer, about 8.0% sucrose, about 0.01% polysorbate 80; and wherein the immunoconjugate comprises: (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; and (b) monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (mc-vc-PAB) linker.

[0032] In another aspect, the present disclosure provides a pharmaceutical composition comprising an immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer; wherein the immunoconjugate comprises (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; (b) an effector agent conjugated to the recombinant antibody. In some embodiments, the pharmaceutical composition has a pH of about 5.0 to about 7.0. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable buffer; wherein the buffer comprises citrate, phosphate, acetate, tromethamine, histidine, succinate, malate, or a-ketoglutarate. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable buffer; wherein the buffer comprises about 10 mM to about 30 mM histidine, and has a pH of about 5 to about 7. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable buffer; wherein the buffer comprises citrate, phosphate, acetate, tromethamine, histidine, succinate, malate, or a-ketoglutarate; wherein the buffer comprises about 20 mM histidine and has a pH of about 6.0. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable stabilizer; wherein the stabilizer prevents denaturation of the recombinant antibody, prevents aggregation of the immunoconjugate, or both. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable stabilizer; wherein the stabilizer comprises a non-ionic surfactant. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable stabilizer; wherein the stabilizer comprises a polysorbate. In some embodiments, the pharmaceutical composition comprises a pharmaceutically acceptable stabilizer; wherein the stabilizer comprises about 0.01% polysorbate-80. In some embodiments, the pharmaceutical composition comprising an immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer, further comprises a pharmaceutically acceptable cryoprotectant. In some embodiments, the pharmaceutical composition comprising an immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer, further comprises a pharmaceutically acceptable cryoprotectant; wherein the cryoprotectant comprises a sugar.In some embodiments, the pharmaceutical composition comprises the immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer, and further comprises a pharmaceutically acceptable cryoprotectant; wherein the cryoprotectant comprises a saccharide comprising about 6% to about 10% sucrose or trehalose. In some embodiments, the pharmaceutical composition comprises the immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer, and further comprises a pharmaceutically acceptable cryoprotectant; wherein the cryoprotectant is about 8.0% sucrose.

[0033] In some embodiments, the pharmaceutical composition comprises an immunoconjugate, a pharmaceutically acceptable buffer, and a pharmaceutically acceptable stabilizer; wherein the immunoconjugate comprises (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; (b) an effector agent conjugated to the recombinant antibody; wherein the recombinant antibody is conjugated to an effector agent, wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, the pharmaceutical composition comprises an effector agent; wherein the effector agent comprises a drug. In some embodiments, the pharmaceutical composition comprises an effector agent; wherein the effector agent comprises an anti-cancer drug. In some embodiments, the pharmaceutical composition comprises a drug; wherein the drug is a chemotherapeutic agent. In some embodiments, the pharmaceutical composition comprises a drug; wherein the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, the pharmaceutical composition comprises a drug that is a microtubule inhibitor; wherein the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansine (or a derivative thereof). In some embodiments, the pharmaceutical composition comprises a drug that is a microtubule inhibitor; wherein the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the pharmaceutical composition comprises an immunoconjugate comprising a recombinant antibody as described above and an effector agent; wherein the ratio of the effector agent to the recombinant antibody in the population of immunoconjugates is about 3 to about 5. In some embodiments, the pharmaceutical composition comprises an immunoconjugate comprising a recombinant antibody as described above and an effector agent; wherein the ratio of the effector agent to the recombinant antibody in the population of immunoconjugates is about 4. In some embodiments, the pharmaceutical composition comprises an immunoconjugate comprising a recombinant antibody as described above and an effector agent; wherein the effector agent is conjugated to the recombinant antibody via a linker.In some embodiments, the pharmaceutical composition comprises an effector agent coupled to the recombinant antibody via a linker as described above; wherein the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the pharmaceutical composition comprises an effector agent coupled to the recombinant antibody via a linker as described above; wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzoxycarbonyl (mc-vc-PAB).

[0034] In another aspect, the present disclosure provides a method of treating a cancer comprising cells expressing CD46 in a human subject in need thereof, the method comprising administering to the subject an immunoconjugate comprising a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of payloads; wherein each payload in the one, two, three, or four pairs of payloads comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine- citrulline-p-aminobenzoxycarbonyl (mc-vc-PAB) linker; wherein each pair in the one, two, three, or four pairs of payloads is conjugated to a pair of cysteine residues of the recombinant antibody; wherein the pair of cysteine residues is selected from the group consisting of: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain. In some embodiments, the method of treating a cancer; wherein the cancer is relapsed or refractory multiple myeloma (RRMM). In some embodiments, the method of treating a cancer; wherein the cancer is metastatic castration-resistant prostate cancer (mCRPC). In some embodiments, the method of treating a cancer comprises administering to the subject the immunoconjugate; wherein the immunoconjugate comprises two pairs of the payloads. In some embodiments, the method of treating a cancer as described above, further comprising detecting the CD46 in the cells. In some embodiments, the method of treating a cancer as described above, further comprising detecting the CD46 in the cells; wherein the detecting comprises immunofluorescence microscopy or immunohistochemistry. In some embodiments, the method of treating a cancer as described above, further comprising detecting the CD46 in the cells; wherein the detecting comprises flow cytometry. In some embodiments, the method of treating a cancer as described above, further comprising detecting the CD46 in the cells; wherein the detecting comprises detecting an amplification of chromosome location 1q21. In some embodiments, the method of treating a cancer as described above, wherein the immunoconjugate is administered to the human subject via intravenous infusion. In some embodiments, the method of treating a cancer as described above, wherein the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, the method of treating a cancer as described above, wherein the immunoconjugate is administered to the human subject every 21 days for at least three cycles. In some embodiments, the method of treating a cancer as described above, wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg.In some embodiments, the method of treating cancer as described above, wherein the recombinant antibody is administered at a dose of about 1.8, about 2.4, about 2.7, or about 3.0 mg / kg. In some embodiments, the method of treating cancer as described above, wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the weight of the human subject in need thereof in kg is the actual body weight of the subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the weight of the human subject in need thereof in kg is the adjusted body weight of the subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the weight of the human subject in need thereof in kg is 100 kg. In some embodiments, the method of treating cancer as described above, wherein the weight of the human subject in need thereof in kg is the actual body weight. In some embodiments, the method of treating cancer as described above, wherein the weight of the human subject in need thereof in kg is the adjusted body weight.

[0035] In another aspect, the present disclosure provides a method of treating metastatic castration-resistant prostate cancer in a human subject in need thereof, the method comprising administering to the subject an immunoconjugate comprising: (i) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; conjugated via a linker to (ii) monomethyl auristatin E (MMAE); wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyl oxycarbonyl (mc-vc-PAB); wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg.

[0036] In another aspect, the present disclosure provides a method of treating relapsed or refractory multiple myeloma in a human subject in need thereof, the method comprising administering to the subject an immunoconjugate comprising: (i) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; conjugated via a linker to (ii) monomethyl auristatin E (MMAE), wherein the linker comprises maleimidocaproyl-valine- citrulline-para-aminobenzyl oxycarbonyl (mc-vc-PAB); wherein the immunoconjugate is administered at a dose of about 1.8 to about 3.0 mg / kg. In some embodiments, the method of treating metastatic castration-resistant prostate cancer or the method of treating relapsed or refractory multiple myeloma in a human subject; wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the calculated weight of the human subject in kg is the actual body weight of the human subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the calculated weight of the human subject in kg is the adjusted body weight of the subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the calculated weight of the human subject in kg is 100 kg. In some embodiments, the method of treating metastatic castration-resistant prostate cancer or the method of treating relapsed or refractory multiple myeloma in a human subject; wherein the calculated weight of the human subject in kg is the adjusted body weight. In some embodiments, the method of treating metastatic castration-resistant prostate cancer or the method of treating relapsed or refractory multiple myeloma in a human subject; wherein the weight of the human subject in kg is the actual body weight.

[0037] In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma further comprises detecting the CD46 in the cell. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma further comprises detecting the CD46 in the cell; wherein the detecting comprises immunofluorescence microscopy or immunohistochemistry. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma further comprises detecting the CD46 in the cell; wherein the detecting comprises flow cytometry. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma further comprises detecting the CD46 in the cell; wherein the detecting comprises detecting amplification of chromosome location 1q21. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma as described above; wherein the immunoconjugate is administered to the human subject via intravenous infusion. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma as described above; wherein the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, the method of treating metastatic castration-resistant prostate cancer in a human subject or the method of treating relapsed or refractory multiple myeloma as described above; wherein the immunoconjugate is administered to the human subject every 21 days for at least three cycles.

[0038] In another aspect, the present disclosure provides a method of treating cancer in a human subject in need thereof, the method comprising administering to the human subject an immunoconjugate comprising: a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; an effector agent conjugated to the recombinant antibody; and wherein the immunoconjugate is administered at a dose of about 1.0 to about 5.0 mg / kg or is administered at a dose of about 1.0 to about 4.0 mg / kg. In some embodiments, the method of treating cancer; wherein the cancer is prostate cancer. In some embodiments, the method of treating prostate cancer; wherein the prostate cancer is metastatic castration-resistant prostate cancer. In some embodiments, the method of treating cancer; wherein the cancer is multiple myeloma. In some embodiments, the method of treating multiple myeloma; wherein the multiple myeloma is relapsed or refractory multiple myeloma. In some embodiments, the method of treating cancer as described above, further comprising detecting CD46 expression in cells of the cancer. In some embodiments, the method of treating cancer as described above, further comprising detecting CD46 expression in cells of the cancer, wherein the detecting comprises immunofluorescence microscopy or immunohistochemistry. In some embodiments, the method of treating cancer as described above, further comprising detecting CD46 expression in cells of the cancer, wherein the detecting comprises flow cytometry. In some embodiments, the method of treating cancer as described above, further comprising detecting CD46 expression in cells of the cancer, wherein the detecting comprises detecting an amplification of chromosome location 1q21. In some embodiments, the method of treating cancer as described above; wherein the cancer has a higher CD46 expression than non-cancerous tissue of the same tissue type from the subject or from a healthy individual. In some embodiments, the method of treating cancer as described above; wherein the cancer comprises an increased copy number of chromosome band 1q21.In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 1.0 to about 4.5 mg / kg, about 1.0 to about 4.0 mg / kg, about 1.0 to about 3.5 mg / kg, about 1.0 to about 3.0 mg / kg, about 1.0 to about 2.7 mg / kg, about 1.0 to about 2.5 mg / kg, about 1.0 to 2.4 mg / kg, 1.5 to about 4.5 mg / kg, 1.5 to about 4.0 mg / kg, about 1.5 to about 3.5 mg / kg, about 1.5 to about 3.0 mg / kg, about 1.5 to about 2.7 mg / kg, about 1.5 to about 2.5 mg / kg, about 1.5 to about 2.4 mg / kg, about 1.5 to about 2.0 mg / kg, about 1.8 to about 4.5 mg / kg, about 1.8 to about 4.0 mg / kg, about 1.8 to about 3.5 mg / kg, about 1.8 to about 3.0 mg / kg, about 1.8 to about 2.7 mg / kg, about 1.8 to about 2.5 mg / kg, about 1.8 to about 2.4 mg / kg, or about 1.8 to about 2.0 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, or about 4.0 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 1.8, about 2.4, about 2.7, or about 3.0 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 1.8 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 2.4 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 2.7 mg / kg. In some embodiments, the method of treating cancer as described above; wherein the immunoconjugate is administered at a dose of about 3.0 mg / kg.In some embodiments, the method of treating cancer in a human subject as described above; wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the weight of the human subject in kg is the actual body weight of the human subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the weight of the human subject in kg is the adjusted body weight of the human subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the weight of the human subject in kg is 100 kg. In some embodiments, the method of treating cancer in a human subject as described above; wherein the weight of the human subject in kg is actual body weight. In some embodiments, the method of treating cancer in a human subject as described above; wherein the weight of the human subject in kg is adjusted body weight. In some embodiments, the method of treating cancer in a human subject as described above, comprising administering to the human subject an immunoconjugate comprising a recombinant antibody; wherein the recombinant antibody is administered to the human subject via intravenous infusion. In some embodiments, the method of treating cancer in a human subject as described above, comprising administering to the human subject an immunoconjugate comprising a recombinant antibody; wherein the recombinant antibody is administered to the subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, the method of treating cancer in a human subject as described above, comprising administering to the human subject an immunoconjugate comprising a recombinant antibody; wherein the recombinant antibody is administered to the human subject every 21 days for at least three cycles. In some embodiments, the method of treating cancer in a human subject as described above, comprising administering to the human subject an immunoconjugate comprising an effector agent; wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, the method of treating cancer in a human subject as described above, comprising administering to the human subject an immunoconjugate comprising an effector agent; wherein the effector agent comprises a drug. In some embodiments, the method of treating cancer in a human subject as described above; wherein the effector agent comprises an anti-cancer drug. In some embodiments, the method of treating cancer in a human subject as described above; wherein the effector agent comprises a drug; wherein the drug is a chemotherapeutic agent. In some embodiments, the method of treating cancer in a human subject as described above; wherein the effector agent comprises a drug; wherein the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, the method of treating cancer in a human subject as described above; wherein the effector agent comprises a drug; wherein the drug is a microtubule inhibitor.In some embodiments, the method of treating cancer in a human subject as described above; wherein the microtubule inhibitor is an auristatin (or derivative thereof), a dolastatin-10 (or derivative thereof), or a maytansinoid (or derivative thereof). In some embodiments, the method of treating cancer in a human subject as described above; wherein the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the method of treating cancer in a human subject as described above; wherein the microtubule inhibitor is monomethyl auristatin E (MMAE). In some embodiments, the method of treating cancer in a human subject as described above comprises administering to the human subject an immunoconjugate comprising an effector agent and a recombinant antibody; wherein the ratio of the effector agent to the recombinant antibody is about 3 to about 5. In some embodiments, the method of treating cancer in a human subject as described above; wherein the ratio of the effector agent to the recombinant antibody is about 4. In some embodiments, the method of treating cancer in a human subject as described above; wherein the effector agent is conjugated to the recombinant antibody via a linker. In some embodiments, the method of treating cancer in a human subject as described above; wherein the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the method of treating cancer in a human subject as described above; wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzoxycarbonyl (mc-vc-PAB). In some embodiments, the method of treating cancer in a human subject as described above; wherein the immunoconjugate binds to CD46 expressed on the surface of a cell and internalizes into the cell. In some embodiments, the method of treating cancer in a human subject as described above; wherein the immunoconjugate internalizes into the cell via macropinocytosis.

[0039] In another aspect, the present disclosure provides an immunoconjugate comprising: a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of payloads; wherein each payload in the one, two, three, or four pairs of payloads comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine- citrulline-p-aminobenzoxycarbonyl (mc-vc-PAB) linker; wherein each pair in the one, two, three, or four pairs of payloads is conjugated to a pair of cysteine residues of the recombinant antibody, wherein the pair of cysteine residues is selected from the group consisting of: C219 of the first heavy chain and C214 of the first light chain, C219 of the second heavy chain and C214 of the second light chain, C225 of the first heavy chain and C225 of the second light chain, and C228 of the first heavy chain and C228 of the second light chain; for use in treating cancer in a human subject comprising cells expressing CD46. In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the cancer is relapsed or refractory multiple myeloma (RRMM). In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the cancer is metastatic castration-resistant prostate cancer (mCRPC). In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the immunoconjugate comprises two pairs of the payloads. In some embodiments, the immunoconjugate for use in treating cancer in a human subject comprising cells expressing CD46 as described above, wherein the cells comprise CD46 as determined by immunofluorescence microscopy or immunohistochemistry. In some embodiments, the immunoconjugate for use in treating cancer in a human subject comprising cells expressing CD46 as described above, wherein the cells comprise CD46 as determined by flow cytometry. In some embodiments, the immunoconjugate for use in treating cancer in a human subject comprising cells expressing CD46 as described above, wherein the cells comprise an amplification of chromosome location 1q21. In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the immunoconjugate is formulated for intravenous infusion. In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, every 28 days, or monthly. In some embodiments, the immunoconjugate for use in treating cancer in a human subject as described above, wherein the immunoconjugate is administered to the human subject every 21 days.In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject as described above, wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject comprising a recombinant antibody as described above, wherein the recombinant antibody is administered at a dose of about 1.8, about 2.4, about 2.7, or about 3.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject as described above; wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the weight of the human subject in kg is the actual body weight of the human subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the weight of the human subject in kg is the adjusted body weight of the subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the weight of the human subject in kg is 100 kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject as described above; wherein the weight of the human subject in kg is the actual body weight. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject as described above; wherein the weight of the human subject in kg is the adjusted body weight.

[0040] In another aspect, the present disclosure provides an immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer in a human subject in need thereof, comprising (i) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; conjugated via a linker to (ii) monomethyl auristatin E (MMAE), wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyl oxycarbonyl (mc-vc-PAB), wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg.

[0041] In another aspect, the present disclosure provides an immunoconjugate for use in treating refractory multiple myeloma in a human subject in need thereof, comprising (i) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; conjugated via a linker to (ii) monomethyl auristatin E (MMAE), wherein the linker comprises maleimidocaproyl-valine-citruline-para-aminobenzyl oxycarbonyl (mc-vc-PAB), wherein the immunoconjugate is administered at a dose of about 1.8 to about 3.0 mg / kg.

[0042] In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject, wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the calculated weight of the human subject in kg is the actual body weight of the subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the calculated weight of the human subject in kg is the adjusted body weight of the subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the calculated weight of the human subject in kg is 100 kg. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject, wherein the weight of the human subject in kg is actual body weight. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject, wherein the weight of the human subject in kg is adjusted body weight. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject comprises a cell; wherein the cell comprises CD46 as determined by immunofluorescence microscopy or immunohistochemistry. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject comprises a cell; wherein the cell comprises CD46 as determined by flow cytometry. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma in a human subject comprises a cell; wherein the cell comprises an amplification of chromosomal location lq21. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma; wherein the immunoconjugate is formulated for intravenous infusion. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma; wherein the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, every 28 days, or monthly. In some embodiments, the immunoconjugate for use in the treatment of metastatic castration-resistant prostate cancer or for use in the treatment of refractory multiple myeloma; wherein the immunoconjugate is administered to the human subject every 21 days for at least three cycles.

[0043] In another aspect, the present disclosure provides an immunoconjugate for use in treating cancer in a human subject in need thereof, comprising: (a) a recombinant antibody that specifically binds CD46, the recombinant antibody comprising a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and a light chain (LC) variable region comprising three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1, HC CDR2, and HC CDR3 comprise the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively, and the LC CDR1, LC CDR2, and LC CDR3 comprise the amino acid sequences of SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6, respectively; (b) an effector agent conjugated to the recombinant antibody; and wherein the immunoconjugate is administered at a dose of about 1.0 to about 5.0 mg / kg. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the cancer is prostate cancer. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the prostate cancer is metastatic castration-resistant prostate cancer. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the prostate cancer is multiple myeloma. In some embodiments, the immunoconjugate for use in treating multiple myeloma in a human subject; wherein the multiple myeloma is relapsed or refractory multiple myeloma. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the cancer comprises cells that express CD46, as determined by immunofluorescence microscopy or immunohistochemistry. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the cancer comprises cells that express CD46, as determined by flow cytometry. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the cancer comprises an amplification of chromosome location 1q21. In some embodiments, the immunoconjugate for use in treating cancer in a human subject; wherein the cancer has higher CD46 expression than non-cancerous tissue of the same tissue type from the subject or from a healthy individual.In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.0 to about 4.5 mg / kg, about 1.0 to about 4.0 mg / kg, about 1.0 to about 3.5 mg / kg, 1.0 to about 3.0 mg / kg, about 1.0 to about 2.7 mg / kg, about 1.0 to about 2.5 mg / kg, about 1.0 to about 2.4 mg / kg, about 1.5 to about 4.5 mg / kg, about 1.5 to about 4.0 mg / kg, about 1.5 to about 3.5 mg / kg, about 1.5 to about 3.0 mg / kg, about 1.5 to about 2.7 mg / kg, about 1.5 to about 2.5 mg / kg, about 1.5 to about 2.4 mg / kg, about 1.5 to about 2.0 mg / kg, about 1.8 to about 4.5 mg / kg, about 1.8 to about 4.0 mg / kg, about 1.8 to about 3.5 mg / kg, about 1.8 to about 3.0 mg / kg, about 1.8 to about 2.7 mg / kg, about 1.8 to about 2.5 mg / kg, about 1.8 to about 2.4 mg / kg, or about 1.8 to about 2.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.2 to about 3.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, or about 4.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.8, about 2.4, about 2.7, or about 3.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.8, about 2.4, about 2.7, or about 3.0 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 1.8 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 2.4 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 2.7 mg / kg. In some embodiments, the immunoconjugate for use in the treatment of cancer in a human subject; wherein the immunoconjugate is administered at a dose of about 3.0 mg / kg.In some embodiments, an immunoconjugate for use in treating cancer in a human subject; wherein: if the actual body weight of the human subject is less than the adjusted body weight of the subject, the weight of the human subject in kg is the actual body weight of the subject; if the actual body weight of the human subject is greater than or equal to the adjusted body weight of the subject, and the adjusted body weight of the human subject is less than 100 kg, the weight of the human subject in kg is the adjusted body weight of the subject; or if the adjusted body weight of the human subject is greater than or equal to 100 kg, the weight of the human subject in kg is 100 kg. In some embodiments, an immunoconjugate for use in treating cancer in a human subject; wherein the weight of the human subject in kg is actual body weight. In some embodiments, an immunoconjugate for use in treating cancer in a human subject; wherein the weight of the human subject in kg is adjusted body weight. In some embodiments, an immunoconjugate comprising a recombinant antibody for use in treating cancer in a human subject; wherein the recombinant antibody is formulated for intravenous infusion. In some embodiments, an immunoconjugate comprising a recombinant antibody for use in treating cancer in a human subject; wherein the recombinant antibody is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, an immunoconjugate comprising a recombinant antibody for use in treating cancer in a human subject; wherein the recombinant antibody is administered to the human subject every 21 days. In some embodiments, an immunoconjugate comprising an effector agent for use in treating cancer in a human subject; wherein the effector agent comprises a drug (or a prodrug thereof), a peptide, a protein, a detectable label, a liposome containing a drug (or a prodrug thereof), a radionuclide, a viral particle, or a chelate. In some embodiments, an immunoconjugate comprising an effector agent for use in treating cancer in a human subject; wherein the effector agent comprises a drug. In some embodiments, an immunoconjugate comprising an effector agent for use in treating cancer in a human subject; wherein the effector agent comprises an anti-cancer drug. In some embodiments, an immunoconjugate comprises an effector agent; wherein the effector agent comprises a chemotherapeutic agent. In some embodiments, an immunoconjugate comprises an effector agent; wherein the effector agent comprises a drug; wherein the drug is a microtubule inhibitor, a DNA damaging agent, or a polymerase inhibitor. In some embodiments, an immunoconjugate comprises a microtubule inhibitor, wherein the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansine (or a derivative thereof). In some embodiments, an immunoconjugate comprises a microtubule inhibitor, wherein the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF).In some embodiments, the immunoconjugate comprises an effector agent; wherein the effector agent comprises a drug; wherein the drug is a microtubule inhibitor, wherein the microtubule inhibitor is monomethyl auristatin E (MMAE). In some embodiments, the immunoconjugate comprises an effector agent and a recombinant antibody; wherein the ratio of the effector agent to the recombinant antibody is about 3 to about 5. In some embodiments, the immunoconjugate comprises an effector agent and a recombinant antibody; wherein the ratio of the effector agent to the recombinant antibody is about 4. In some embodiments, the immunoconjugate comprises an effector agent and a recombinant antibody; wherein the effector agent is conjugated to the recombinant antibody via a linker. In some embodiments, the immunoconjugate comprises an effector agent conjugated to a recombinant antibody via a linker; wherein the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. In some embodiments, the immunoconjugate comprises an effector agent conjugated to a recombinant antibody via a linker; wherein the linker comprises maleimidocaproyl-valine-citrulline-para-aminobenzyloxy carbonyl (mc-vc-PAB). In some embodiments, the immunoconjugate comprises an effector agent and a recombinant antibody; wherein the immunoconjugate binds to CD46 expressed on the surface of a cell and internalizes into the cell. In some embodiments, the immunoconjugate comprises an effector agent and a recombinant antibody; wherein the immunoconjugate internalizes into the cell via macropinocytosis.

[0044] In another aspect, the present disclosure provides a pharmaceutical formulation for treating metastatic castration-resistant prostate cancer in a human subject in need thereof, comprising an immunoconjugate at a concentration of about 10.0 ± 1.0 mg / mL, about 20 mM histidine buffer, about 8.0% sucrose, about 0.01% polysorbate 80; and wherein the immunoconjugate comprises: a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of adducts; wherein each adduct of the one, two, three, or four pairs of adducts comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine-citrulline-para-aminobenzyloxy carbonyl (mc-vc-PAB) linker; wherein each pair of the one, two, three, or four pairs of adducts is conjugated to a pair of cysteine residues of the recombinant antibody, wherein the pair of cysteine residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain.

[0045] In another aspect, the present disclosure provides a pharmaceutical formulation for use in treating refractory multiple myeloma in a human subject in need thereof comprising an immunoconjugate at a concentration of about 10.0 ± 1.0 mg / mL, about 20 mM histidine buffer, about 8.0% sucrose, about 0.01% polysorbate 80; and wherein the immunoconjugate comprises: a recombinant antibody comprising: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of payloads; wherein each payload of the one, two, three, or four pairs of payloads comprises monomethyl auristatin E (MMAE) conjugated to the recombinant antibody via a maleimidocaproyl-valine- citrulline-p-aminobenzoxycarbonyl (mc-vc-PAB) linker; wherein each pair of the one, two, three, or four pairs of payloads is conjugated to a pair of cysteine residues of the recombinant antibody, wherein the pair of cysteine residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain. BRIEF DESCRIPTION OF DRAWINGS

[0046] FIG. 1 Flow cytometry traces showing binding of YS5FL to prostate cells are depicted.

[0047] FIG. 2 Flow cytometry traces showing binding of YS5FL to multiple myeloma cells are depicted.

[0048] FIG. 3 Is a graph showing the structure of the FOR46 immunoconjugate described herein.

[0049] FIG. 4 Is a hydrophobic interaction chromatography trace showing the stoichiometry of MMAE conjugation to YS5FL in FOR46.

[0050] FIG. 5A Is a CT scan showing metastatic lesions in castration-resistant prostate cancer patient 001-09-28 (dosed at 2.7 mg / kg FOR46) on cycle 3 day 15 and pre-treatment.

[0051] FIG. 5B Is a graph illustrating the reduction in serum PSA in patient 001-09-28.

[0052] FIG. 6is a lane plot showing patient status in a prostate cancer dose escalation trial. PR: partial response; EOS: end of study; EOT: end of treatment; PD: progressive disease.

[0053] FIG. 7A is a plot showing the response of multiple myeloma patient 006-05-008 to treatment with 1.8 mg / kg FOR46.

[0054] FIG. 7B is a plot showing the response of multiple myeloma patient 001-06-012 to treatment with 2.4 mg / kg FOR46.

[0055] FIG. 7C is a plot showing the response of multiple myeloma patient 003-06-014 to treatment with 2.4 mg / kg FOR46.

[0056] FIG. 8 is a lane plot showing patient status in a multiple myeloma dose escalation and expansion trial. EOS: end of study; EOT: end of treatment; PD: progressive disease. DETAILED DESCRIPTION

[0057] CD46, also known as CD46 complement regulatory protein, cluster of differentiation 46, and membrane cofactor protein, is an inhibitory complement receptor. Overexpression of CD46 has been observed in several cancers, such as breast cancer, colorectal cancer, liver cancer, lung cancer, or prostate cancer. In some cases, overexpression of CD46 is characterized as a negative prognostic factor. For example, in breast cancer patients and ovarian cancer patients, overexpression of CD46 is associated with shorter progression-free time and shorter overall survival time. Provided herein are antibodies and immunoconjugates targeting CD46 for the treatment of cancer. Also provided herein are specific dosing and administration regimens for administering CD46-targeting antibodies and immunoconjugates to human subjects in need thereof. Also provided herein are formulations of CD46-targeting antibodies and immunoconjugates for administration to subjects in need thereof that provide, for example, sufficient stability, cryoprotection, and the like.

[0058] DEFINITIONS

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter belongs. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of any subject matter claimed. As used herein, the section headings are for organizational purposes only and are not to be construed as limiting the subject matter described. In this application, the use of the singular includes the plural unless specifically stated otherwise. Note that as used herein and in the appended claims, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. In this application, the use of "or" means "and / or" unless specifically stated otherwise. Furthermore, the use of the term "including" as well as other forms such as "include", "includes" and "included" is not limiting.

[0060] As used herein, ranges and amounts can be expressed as "about" a particular value or range. About also includes the exact amount. Hence "about 5 μL" means "about 5 μL" and also "5 μL". In general, the term "about" comprises amounts expected to be within experimental error.

[0061] The terms "antibody" and "immunoglobulin" are used interchangeably herein and are used in the broadest sense and include fully assembled antibodies, antibody fragments that can bind an antigen, such as Fab, F(ab')2, Fv, single chain antibodies (scFv), diabodies, antibody chimeras, hybrid antibodies, bispecific antibodies, and the like.

[0062] The terms "monoclonal antibody" and "mAb" are used interchangeably herein and refer to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies of the population are identical except for possible naturally occurring mutations that can be present in minor amounts.

[0063] The terms "native antibody" and "native immunoglobulin" are heterotetrameric glycoproteins of about 150,000 daltons, composed of two identical light (L) chains and two identical heavy (H) chains. Each light chain is linked to a heavy chain by one covalent disulfide bond, while the number of disulfide bonds between the heavy chains can vary among the different immunoglobulin isotypes. Each heavy and light chain also has regularly spaced intrachain disulfide bridges. At one end of each heavy chain is a variable domain (VH) followed by a number of constant domains. At one end of each light chain is a variable domain (VL) followed by a constant domain; the light chain constant domain can align with the first constant domain of the heavy chain. Particular amino acid residues are identified as forming an interface between the light chain and heavy chain variable domains.

[0064] As used herein, the term "hypervariable region" refers to amino acid residues of an antibody that are responsible for antigen binding. The hypervariable region comprises amino acid residues from a "complementarity determining region" or "CDR" (i.e. residues 24-34 (L1), 50-56 (L2) and 89-97 (L3) in the light chain variable domain and residues 31-35 (H1), 50-65 (H2) and 95-102 (H3) in the heavy chain variable domain; Kabat et al. (1991) Sequences of Proteins of Immunological Interest Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242 (herein "Kabat et al.")) and / or those residues from a "hypervariable loop" (i.e. residues 26-32 (L1), 50-52 (L2) and 91-96 (L3) in the light chain variable domain and residues (H1), 53-55 (H2) and 96-101 (H3) in the heavy chain variable domain; Chothia and Lesk (1987) J. Mol. Biol., 196: 901-917). "Framework" or "FR" residues are those variable domain residues other than the hypervariable region residues as herein denoted.

[0065] In some cases, the CDRs of an antibody are determined according to: (i) the Kabat numbering system, Kabat et al., (1991) Sequences of Proteins of Immunological Interest Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242; or (ii) the Chothia numbering scheme, which is referred to herein as“Chothia CDRs” (see, e.g., Chothia and Lesk, 1987, J. Mol. Biol., 196:901-917; Al-Lazikani et al., 1997, J. Mol. Biol., 273:927-948; Chothia et al., 1992, J. Mol. Biol., 227:799-817; Tramontano A et al., 1990, J. Mol. Biol. 215(1): 175-82; and U.S. Patent No. 7,709,226); or (iii) the ImMunoGeneTics (IMGT) numbering system, e.g., as described in Lefranc, M.-P., 1999, The Immunologist, 7:132-136 and Lefranc, M.-P. et al., 1999, Nucleic Acids Res., 27:209-212 (“IMGT CDRs”); or (iv) MacCallum et al., 1996, J. Mol. Biol., 262:732-745. See also, e.g., Martin, A.,“Protein Sequence and Structure Analysis of Antibody Variable Domains”, in Antibody Engineering, Kontermann and Diibel eds., Chapter 31, pp. 422-439, Springer-Verlag, Berlin (2001).

[0066] With respect to the Kabat numbering system, CDRs within an antibody heavy chain molecule are generally found at amino acid positions 31 to 35 (which optionally can include one or two additional amino acids located after 35 (referred to as 35A and 35B in the Kabat numbering scheme)) (CDR1), amino acid positions 50 to 65 (CDR2), and amino acid positions 95 to 102 (CDR3). Using the Kabat numbering system, CDRs within an antibody light chain molecule are generally found at amino acid positions 24 to 34 (CDR1), amino acid positions 50 to 56 (CDR2), and amino acid positions 89 to 97 (CDR3). As is well known to those skilled in the art, using the Kabat numbering system, the actual linear amino acid sequence of an antibody variable domain can contain fewer or additional amino acids than those shown above, due to the deletion or addition of amino acids at the N- or C-terminus of the variable domain or in the CDRs, and thus the Kabat numbering of amino acids is not necessarily identical to the linear amino acid number.

[0067] As used herein, the term "antigen binding site" refers to the part of an antigen binding molecule that specifically binds to an antigenic determinant. More specifically, the term "antigen binding site" refers to the region of an antibody that comprises the part or parts of the antigen to which it specifically binds and is complementary. When the antigen is large, the antigen binding molecule can bind only to a specific part of the antigen, which is called an epitope. The antigen binding site can be provided by, for example, one or more variable domains (also referred to as variable regions). Preferably, the antigen binding site comprises an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH).

[0068] "Specifically binds" refers to binding that is selective for an antigen and can be distinguished from non-specific or nonspecific interaction. The ability of an antigen binding molecule to bind to a specific antigen can be measured by enzyme-linked immunosorbent assay (ELISA) or other techniques familiar to one skilled in the art, for example using surface plasmon resonance (SPR) technology (analysis on a BIAcore instrument) (Liljeblad et al., Glyco J 17, 323-329 (2000)) and traditional binding assays (Heeley, Endocr Res 28, 217-229 (2002)). In one embodiment, the extent of binding of an antigen binding molecule to an unrelated protein is less than about 10% of the binding of the antigen binding molecule to the antigen, as measured by, for example, SPR. In certain embodiments, the dissociation constant (Kd) of a molecule that binds to an antigen is < 1 mM, < 100 nM, < 10 nM, < 1 nM, < 0.1 nM, < 0.01 nM, or < 0.001 nM (e.g., 10-7M or less, e.g., 10-7M to 10-13M, e.g., 10-9M to 10-13M).

[0069] Immunoglobulins can be assigned to different classes depending on the amino acid sequences of the constant regions of their heavy chains. There are five major classes of human immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these can be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. The heavy chain constant regions which correspond to the different classes of immunoglobulins are called a, d, e, g, and m, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known. Different isotypes have different effector functions. For example, human IgG1 and IgG3 isotypes have ADCC (antibody-dependent cell-mediated cytotoxicity) activity. The light chains of antibodies (immunoglobulins) from any vertebrate species can be assigned to one of two clearly distinct types, called kappa (K) and lambda (l), based on the amino acid sequences of their constant domains.

[0070] As used herein, the term "chimeric antibody" refers to an antibody in which a portion of the heavy and / or light chain is derived from a particular source (e.g., protein) or species, while the remainder of the heavy and / or light chain is derived from a different source (e.g., protein) or species.

[0071] As used herein, the term "recombinant human antibody" is intended to include all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies isolated from a host cell such as a NSO or CHO cell or from a transgenic animal (e.g., a mouse) that is capable of producing a repertoire of human antibodies, or antibodies expressed using a recombinant expression vector transfected into a host cell. Such recombinant human antibodies have variable and constant regions in a rearranged form. In some instances, a recombinant human antibody has been subjected to in vivo somatic hypermutation. Thus, the amino acid sequences of the VH and VL regions of recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, can not naturally exist within the human antibody germline repertoire in vivo.

[0072] As used herein, the term "valency" denotes the presence of a particular number of binding sites for antigens in an antigen binding molecule. Thus, the terms "bivalent", "tetravalent", and "hexavalent" denote the presence of two binding sites, four binding sites, and six binding sites, respectively, in an antigen binding molecule. Bispecific antibodies according to the application are at least "bivalent", and can be "trivalent" or "multivalent" (e.g., "tetravalent" or "hexavalent"). In particular aspects, antibodies of the application have two or more binding sites and are bispecific. That is, an antibody can be bispecific even in the presence of more than two binding sites (i.e., the antibody is trivalent or multivalent). In particular, the application relates to bispecific bivalent antibodies having one binding site for each antigen to which they are specifically binding.

[0073] The term "monospecific" antibody as used herein denotes an antibody having one or more binding sites, each of which binds to the same epitope of the same antigen.

[0074] The terms "individual," "subject," and "patient" are used interchangeably herein and refer to any mammal. In some embodiments, the mammal is a human. In some embodiments, the mammal is non-human. None of these terms requires or implies supervision (e.g., continuous or intermittent) by a health care worker (e.g., a physician, a registered nurse, a nurse practitioner, a physician's assistant, a nursing aide, or a hospice worker).

[0075] The term "percent (%) amino acid sequence identity" as used herein with respect to a sequence is defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the specific sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as EMBOSS MATCHER, EMBOSS WATER, EMBOSS STRETCHER, EMBOSS NEEDLE, EMBOSS LALIGN, BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared.

[0076] The terms "cancer" and "tumor" are used interchangeably herein to encompass all types of cancerous processes and / or cancerous growths. In embodiments, cancer includes primary tumors as well as metastatic tissue or malignantly transformed cells, tissues, or organs. In embodiments, cancer encompasses all histopathology and stages of cancer, e.g., stages of invasiveness / severity. In embodiments, cancer includes recurrent and / or resistant cancer.

[0077] "Treatment" (and grammatical variations thereof such as "treat" or "treating"), as used herein, means clinical intervention in an attempt to alter the natural course of the individual being treated, and can be performed either for prophylaxis or during the course of clinical pathology. Desirable effects of treatment include, but are not limited to, preventing occurrence or reoccurrence of disease, alleviation of symptoms, diminishment of any direct or indirect pathological consequences of the disease, preventing metastasis, decreasing rate of disease progression, amelioration or palliation of the disease state, and remission or improved prognosis. In some embodiments, the molecules of the application are used to delay development of a disease or to slow the progression of a disease.

[0078] As used herein, the “ideal body weight” (“IBW”) for a male is 50 kg + 2.3 kg x (actual height - 60 inches), and for a female is 45.5 kg + 2.3 kg x (actual height - 60 inches).

[0079] As used herein, the “adjusted body weight” (“AJBW”) is IBW + 0.4 x (actual body weight - IBW).

[0080] Anti-CD46 recombinant antibodies

[0081] In some embodiments, disclosed herein are recombinant antibodies (or antigen binding fragments thereof) that specifically bind CD46. In some embodiments, the antibody or antigen binding fragment or variant thereof is a monoclonal antibody. In some embodiments, the antibody or antigen binding fragment or variant thereof is a human antibody, murine antibody, humanized antibody, or chimeric antibody. In some embodiments, the antibody comprises or consists of a functional fragment of a full-length antibody (e.g., an antigen binding fragment of a full-length antibody), such as a monovalent Fab, a divalent Fab’2, a single chain variable region fragment (scFv), or a functional fragment or variant thereof. In some embodiments, the recombinant antibody (or antigen binding fragment thereof) comprises an immunoglobulin variable heavy chain domain (VH). In some embodiments, the recombinant antibody (or antigen binding fragment thereof) comprises an immunoglobulin variable light chain domain (VL). In some embodiments, the recombinant antibody (or antigen binding fragment thereof) comprises a VH and a VL.

[0082] In some embodiments, the recombinant antibody (or antigen binding fragment thereof) comprises an Fc region. In some embodiments, the recombinant antibody (or antigen binding fragment thereof) is a full-length antibody. In some embodiments, the recombinant antibody (or antigen binding fragment thereof) comprises: a first light chain comprising a light chain variable region and a light chain constant region; a first heavy chain comprising a heavy chain variable region and a heavy chain constant region; a second light chain comprising a light chain variable region and a light chain constant region; and a second heavy chain comprising a heavy chain variable region and a heavy chain constant region. In some embodiments, the first light chain and the second light chain have at least 95%, 96%, 97%, 98%, 99%, or 100% sequence identity. In some embodiments, the first light chain and the second light chain bind to the same epitope. In some embodiments, the first heavy chain and the second heavy chain have at least 95%, 96%, 97%, 98%, 99%, or 100% sequence identity. In some embodiments, the first heavy chain and the second heavy chain bind to the same epitope.

[0083] In some embodiments, the recombinant antibody (or antigen binding fragment thereof) is derived from a non-human (e.g., rabbit or mouse) antibody. In some cases, a humanized version of a non-human antibody contains minimal non-human sequences to preserve the original antigen specificity. In some cases, the humanized antibody is a human immunoglobulin (acceptor antibody) in which CDRs of the acceptor antibody are replaced by residues from CDRs of a non-human immunoglobulin (donor antibody), such as a rat, rabbit, or mouse donor that has a desired specificity, affinity, avidity, binding kinetics, and / or ability. In some cases, one or more framework region (FR) residues of the human immunoglobulin are replaced by the corresponding non-human residues of the donor antibody.

[0084] Complementarity Determining Region (CDR)

[0085] In some embodiments, the CD46-binding recombinant antibody comprises an immunoglobulin variable heavy domain (VH) comprising at least one, two, or three complementarity determining regions (CDRs) disclosed in Table 1 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0086] In some embodiments, the CD46-binding recombinant antibody comprises an immunoglobulin variable light domain (VL) comprising at least one, two, or three complementarity determining regions (CDRs) disclosed in Table 2 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0087] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising at least one, two, or three complementarity determining regions (CDRs) disclosed in Table 1 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity); and a VL comprising at least one, two, or three complementarity determining regions (CDRs) disclosed in Table 2 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0088] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising a CDR1 of SEQ ID NO: 1, a CDR2 of SEQ ID NO: 2, and a CDR3 of SEQ ID NO: 3.

[0089] In some embodiments, the CD46-binding recombinant antibody comprises a VL comprising a CDR1 of SEQ ID NO: 4, a CDR2 of SEQ ID NO: 5, and a CDR3 of SEQ ID NO: 6.

[0090] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising a CDR1 of SEQ ID NO: 1, a CDR2 of SEQ ID NO: 2, and a CDR3 of SEQ ID NO: 3; and a VL comprising a CDR1 of SEQ ID NO: 4, a CDR2 of SEQ ID NO: 5, and a CDR3 of SEQ ID NO: 6.

[0091] Table 1. VH CDR Amino Acid Sequences of Anti-CD46 Antibodies as defined by Kabat et al.

[0092]

[0093] Table 2. VL CDR Amino Acid Sequences of Anti-CD46 Antibodies as defined by Kabat et al.

[0094]

[0095] In some embodiments, the CDRs described herein comprise one, two, or three amino acid modifications. In some embodiments, the modifications are substitutions, additions, or deletions. In some embodiments, the CDRs described herein comprise one, two, or three conservative amino acid substitutions. In some embodiments, the one, two, or three amino acid modifications do not substantially modify binding to human CD46. In some embodiments, the one, two, or three amino acid modifications modify binding to human CD46. In some embodiments, the VH-CDR3 and / or VL-CDR3 comprises an amino acid substitution that modifies binding to human CD46, immunogenicity, or some other characteristic. In some embodiments, the amino acid substitution is alanine (A).

[0096] Variable heavy chain region and variable light chain region

[0097] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising an amino acid sequence disclosed in Table 3 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0098] In some embodiments, the CD46-binding recombinant antibody comprises a VL comprising an amino acid sequence disclosed in Table 4 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0099] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising an amino acid sequence disclosed in Table 3 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity); and a VL comprising an amino acid sequence disclosed in Table 4 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0100] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising an amino acid sequence of SEQ ID NO: 7 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0101] In some embodiments, the CD46-binding recombinant antibody comprises a VL comprising an amino acid sequence of SEQ ID NO: 8 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0102] In some embodiments, the CD46-binding recombinant antibody comprises a VH comprising an amino acid sequence of SEQ ID NO: 7 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity); and a VL comprising an amino acid sequence of SEQ ID NO: 8 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0103] Table 3. Amino acid sequences of anti-CD46 variable heavy chain binding domains.

[0104]

[0105] Table 4. Amino acid sequences of anti-CD46 variable light chain binding domains.

[0106]

[0107] Heavy and light chains

[0108] In some embodiments, the CD46-binding recombinant antibody comprises a heavy chain comprising an amino acid sequence disclosed in Table 5 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0109] In some embodiments, the CD46-binding recombinant antibody comprises a heavy chain comprising an amino acid sequence disclosed in Table 5 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0110] In some embodiments, the CD46-binding recombinant antibody comprises a heavy chain comprising an amino acid sequence disclosed in Table 5 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity); and a light chain comprising an amino acid sequence disclosed in Table 6 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0111] In some embodiments, the CD46-binding recombinant antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0112] In some embodiments, the CD46-binding recombinant antibody comprises a light chain comprising the amino acid sequence of SEQ ID NO: 10 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0113] In some embodiments, the CD46-binding recombinant antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity); and a light chain comprising the amino acid sequence of SEQ ID NO: 10 or a sequence substantially identical thereto (e.g., a sequence having at least 90%, 95%, 96%, 97%, 98%, or 99% sequence identity).

[0114] Table 5. Amino acid sequences of anti-CD46 heavy chains.

[0115]

[0116]

[0117] Table 6. Amino acid sequences of anti-CD46 light chains.

[0118]

[0119] In some embodiments, the anti-CD46 antibodies disclosed herein include an immunoglobulin constant region (e.g., an Fc region). Exemplary Fc regions can be selected from the heavy chain constant region of IgGl, IgG2, IgG3, or IgG4; more particularly, the heavy chain constant region of human IgGl or IgG4. In some embodiments, the immunoglobulin constant region (e.g., Fc region) is altered, e.g., mutated, to increase or decrease one or more of: Fc receptor binding, antibody glycosylation, the number of cysteine residues, effector cell function, or complement function.

[0120] Effector agents

[0121] In some embodiments, an immunoconjugate comprising an anti-CD46 antibody linked to an effector agent (or a prodrug thereof) is disclosed herein. In some embodiments, the effector agent is a drug (or a prodrug thereof), a small molecule, a protein, a peptide, an antibody, a ligand, a receptor, a cytotoxic agent, a cytostatic agent, a liposome, a nanoparticle, a radionuclide, a cytokine, a chemokine, a toxin, a detectable label, a viral particle, or a chelate.

[0122] In some embodiments, the effector agent is a drug (or a prodrug thereof). In some embodiments, the effector agent is an anti-cancer agent (or a prodrug thereof). In some embodiments, the effector agent is a chemotherapeutic agent (or a prodrug thereof). In some embodiments, the effector agent is a microtubule inhibitor (or a prodrug thereof), a DNA damaging agent (or a prodrug thereof), or a polymerase inhibitor (or a prodrug thereof).

[0123] In some embodiments, the effector agent is a microtubule inhibitor (or a prodrug thereof). In some embodiments, the microtubule inhibitor is an auristatin (or a derivative thereof), a dolastatin-10 (or a derivative thereof), or a maytansine (or a derivative thereof). In some embodiments, the microtubule inhibitor is monomethyl auristatin F (MMAF), auristatin E (AE), monomethyl auristatin E (MMAE), valine-citrulline MMAE (vcMMAE), or valine-citrulline MMAF (vcMMAF). In some embodiments, the microtubule inhibitor is monomethyl auristatin E (MMAE).

[0124] In some embodiments, the effector agent comprises or consists of a compound of Formula A:

[0125]

[0126] Molecular Formula: C 39 H 67 N5O7

[0127] In certain embodiments, the effector comprises a detectable label. Suitable detectable labels include, but are not limited to, radio-opaque labels, nanoparticles, PET labels, MRI labels, radioactive labels, and the like. Of the radionuclides useful in various embodiments of the application, gamma-emitters, positron emitters, X-ray emitters, and fluorescent emitters are suitable for localization, diagnosis, and / or staging and / or therapy, while beta and alpha emitters, as well as electron and neutron capturers, such as boron and uranium, are also useful for therapy.

[0128] Immunoconjugates

[0129] In one aspect, provided herein are immunoconjugates comprising an anti-CD46 antibody and an effector agent. In some embodiments, the methods described herein utilize these immunoconjugates.

[0130] In some embodiments, the immunoconjugate comprises an anti-CD46 antibody (or antigen binding fragment thereof) described herein. In some embodiments, the immunoconjugate comprises a YS5FL antibody (or antigen binding fragment thereof).

[0131] In some embodiments, the effector agent is conjugated to the anti-CD46 antibody. In some embodiments, the effector agent is linked to the anti-CD46 antibody via a linker. In some embodiments, the linker is a peptide linker, a small molecule linker, or a linker comprising a peptide and a small molecule. Exemplary peptide linkers include, but are not limited to, a peptide linker comprising glycine, serine, or glycine and serine.

[0132] In some embodiments, the linker is cleavable. In some embodiments, the linker is cleaved only upon internalization into a cell. In some embodiments, the cleavable linker is cleavable only upon internalization into a cancer cell. In some embodiments, the cleavable portion of the linker is a peptide (e.g., a dipeptide, e.g., ValCit). In some embodiments, the cleavable linker is cleavable by a cathepsin. In some embodiments, the linker comprises a maleimide. In some embodiments, the linker comprises caproic acid. In some embodiments, the linker comprises a maleimide and caproic acid. In some embodiments, the linker comprises a maleimide, caproic acid, and a cleavable dipeptide.

[0133] In some embodiments, the linker comprises or consists of a maleimidocaproyl-valine-citrulline-p-aminobenzoxycarbonyl (mc-vc-PAB).

[0134] In some embodiments, the linker comprises or consists of a compound of Formula B:

[0135]

[0136]

[0137] In some embodiments, the effector agent is linked to the light chain of an anti-CD46 antibody. In some embodiments, the effector agent is linked to the light chain constant region of an anti-CD46 antibody. In some embodiments, the effector agent is linked to the heavy chain of an anti-CD46 antibody. In some embodiments, the effector agent is linked to the heavy chain constant region of an anti-CD46 antibody.

[0138] In some embodiments, the effector moiety is linked to a cysteine ​​residue of an anti-CD46 antibody. In some embodiments, the anti-CD46 antibody is partially reduced prior to coupling to the effector moiety such that 1-4 interchain disulfide bonds are reduced, while intrachain disulfide bonds are not reduced. Partial reduction exposes paired cysteine ​​residues, making them susceptible to coupling with adducts such as mc-vc-PAB-MMAE. In some embodiments, the following interchain cysteine ​​pairs of YS5FL are exposed: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second light chain; and C228 of the first heavy chain and C228 of the second light chain. In some embodiments, an effector such as mc-vc-PAB-MMAE is coupled to 0, 1, 2, 3, or 4 pairs of cysteine ​​residues on YS5FL.

[0139] In some embodiments, the ratio of effector to anti-CD46 antibody is c. In some embodiments, the ratio of effector to anti-CD46 antibody is 2:1, 4:1, 6:1, or 8:1. In some embodiments, the ratio of effector to anti-CD46 antibody is about 4:1. In some embodiments, the average ratio of effector to anti-CD46 antibody is about 3.7:1. In some embodiments, if the immunoconjugate comprises two or more effectors, each effector is the same. In some embodiments, if the immunoconjugate comprises two or more effectors, at least two effectors are different. In some embodiments, the ratio of effector to anti-CD46 antibody is about 4:1, and each effector is the same.

[0140] Exemplary Immunoconjugates

[0141] Exemplary immunoconjugates provided herein include an anti-CD46 YS5FL antibody linked to a monomethyl auristatin E (MMAE) effector via maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (mc-vc-PAB). In some embodiments, the ratio of MMAE to YSFL antibody is about 4:1.

[0142] In some embodiments, the immunoconjugate comprises an antibody conjugate in the following formula C, wherein the heavy chain comprises SEQ ID NO: 9; and the light chain comprises SEQ ID NO: 10. This immunoconjugate is also referred to herein as FOR46, and comprises the YS5FL antibody linked to MMAE via a mc-vc-PAB linker.

[0143]

[0144] In some embodiments, the anti-CD46 immunoconjugates described herein are prepared by a method comprising reducing or partially reducing the interchain disulfide bonds of the immunoglobulin. In some embodiments, the anti-CD46 immunoconjugates described herein are prepared by a method comprising reducing or partially reducing the interchain disulfide bonds of the immunoglobulin. In some embodiments, the reducing agent is dithiothreitol (DTT) or tris(2-carboxyethyl)phosphine (TCEP). In some embodiments, the effector-linker complex comprising a maleimide-reactive group is coupled to the reduced cysteines of the immunoglobulin. In some embodiments, the effector-linker complex is mc-vc-PAB-MMAE.

[0145] In some embodiments, the effector-linker complex is conjugated to C219, C225, or C228 of the YS5FL heavy chain (SEQ ID NO: 9), or C214 of the YS5FL light chain (SEQ ID NO: 10), or any combination thereof. In some embodiments, the effector-linker complex is conjugated to C219 of the YS5FL heavy chain and C214 of the YS5FL light chain. In some embodiments, the anti-CD46 immunoconjugate comprises two YS5FL heavy chains and two YS5FL light chains, and the effector-linker complex is conjugated to C219 of the first YS5FL heavy chain, C214 of the first YS5FL light chain, C219 of the second YS5FL heavy chain, and C214 of the second YS5FL light chain. In some embodiments, the anti-CD46 immunoconjugate comprises two YS5FL heavy chains, and the effector-linker complex is conjugated to C225 of the first YS5FL heavy chain and C225 of the second YS5FL heavy chain. In some embodiments, the anti-CD46 immunoconjugate comprises two YS5FL heavy chains, and the effector-linker complex is conjugated to C228 of the first YS5FL heavy chain and C228 of the second YS5FL heavy chain. In some embodiments, the immunoconjugate comprises two, four, six, or eight effectors, and the effectors are conjugated to any one, two, three, or four of the following pairs of cysteines, respectively: C219 of HC1 and C214 of LC1; C219 of HC2 and C214 of LC2; C225 of HC1 and C225 of HC2; and C228 of HC1 and C228 of HC2.

[0146] Binding and activity of immunoconjugates to target cells

[0147] In some embodiments, the anti-CD46 antibodies or immunoconjugates described herein bind to CD46 expressed on the surface of a target cell (e.g., a cancer cell) and are internalized by the cell. In some embodiments, the antibodies or immunoconjugates are internalized into the target cell via macropinocytosis. In some embodiments, the antibodies or immunoconjugates target the lysosomes of the cell after internalization. In some embodiments, the antibodies or immunoconjugates induce internalization into the cell without cross-linking.

[0148] In some embodiments, the anti-CD46 antibodies or immunoconjugates described herein mediate killing of a target cell (e.g., a cancer cell) after internalization. In some embodiments, the anti-CD46 antibodies or immunoconjugates induce apoptosis of a target cell (e.g., a cancer cell) after internalization. In some embodiments, the anti-CD46 antibodies or immunoconjugates inhibit cell division of a target cell (e.g., a cancer cell) after internalization. In some embodiments, the anti-CD46 antibodies or immunoconjugates selectively inhibit cell division of a cancer cell after internalization, while not inhibiting cell division of a non-cancer cell after internalization.

[0149] Production of antibodies or antigen-binding fragments thereof

[0150] In some embodiments, antibodies (and antigen-binding fragments thereof) are produced using any method known in the art useful for synthesizing antibodies, particularly by chemical synthesis or by recombinant expression techniques.

[0151] In some embodiments, the antibodies (or antigen-binding fragments thereof) are recombinantly expressed. In some embodiments, the nucleic acid encoding the antibodies (or antigen-binding fragments thereof) is assembled from chemically synthesized oligonucleotides. In some embodiments, nucleic acid molecules encoding the antibodies are produced from a suitable source (e.g., an antibody cDNA library, or a cDNA library produced from any tissue or cell expressing immunoglobulin) by PCR amplification using synthetic primers that hybridize to the 3’ and 5’ ends of the sequence or by cloning using oligonucleotide probes specific for the sequence of the particular gene.

[0152] In some embodiments, the antibodies (or antigen-binding fragments thereof) are prepared by immunizing an animal, such as a mouse, to produce polyclonal or monoclonal antibodies.

[0153] In some embodiments, an expression vector comprising a nucleotide sequence of an antibody or a nucleotide sequence of an antibody is transferred to a host cell by conventional techniques (e.g., electroporation, lipofection, and calcium phosphate precipitation), and the transfected cells are then cultured by conventional techniques to produce the antibody. In some embodiments, expression of the antibody is regulated by a constitutive, inducible, or tissue-specific promoter.

[0154] A variety of host expression vector systems can be used to express the antibodies (or antigen-binding fragments thereof) described herein. These include, but are not limited to, microorganisms such as bacteria (e.g., E. coli and B. subtilis) transformed with recombinant bacteriophage DNA, plasmid DNA or cosmid DNA expression vectors containing antibody or binding fragment thereof-encoding sequences; yeast (e.g., Saccharomyces Pichia) transformed with recombinant yeast expression vectors containing antibody or binding fragment thereof-encoding sequences; insect cell systems infected with recombinant virus expression vectors (e.g., baculovirus) containing antibody or binding fragment thereof-encoding sequences; plant cell systems infected with recombinant virus expression vectors (e.g., CaMV and TMV) or transformed with recombinant plasmid expression vectors (e.g., Ti plasmid) containing antibody or binding fragment thereof-encoding sequences; or mammalian cell systems (e.g., COS, CHO, BH, 293, 293T, 3T3 cells) harboring recombinant expression constructs containing promoters derived from the genome of mammalian cells (e.g., metallothionein promoter) or from mammalian viruses (e.g., adenovirus late promoter; vaccinia virus 7.5K promoter).

[0155] For long-term, high-yield production of recombinant proteins, stable expression can be preferred. In some embodiments, a cell line that stably expresses an antibody is prepared. Following the introduction of foreign DNA, engineered cells are allowed to grow for 1-2 days in an enriched media, and then are switched to a selective media. The selection marker in the recombinant plasmid can be used to

[0156] In some embodiments, any method known in the art for purifying antibodies can be used, for example, by chromatography (e.g., ion exchange, affinity, particularly by affinity for the specific antigen after Protein A, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for purifying protein.

[0157] Expression vectors

[0158] A vector can include any suitable vector derived from a eukaryotic or prokaryotic source. In some cases, a vector is obtained from a bacterial (e.g., E. coli), insect, yeast (e.g., Pichia), algal, or mammalian source. Exemplary bacterial vectors include pACYC177, pASK75, pBAD vector series, pBADM vector series, pET vector series, pETM vector series, pGEX vector series, pHAT, pHAT2, pMal-C2, pMal-P2, pQE vector series, pRSET A, pRSET B, pRSET C, pTrcHis2 series, pZA31-Luc, pZE21-MCS-1, pFLAG ATS, pFLAG CTS, pFLAG MAC, pFLAG Shift-12c, pTAC-MAT-1, pFLAG CTC, or pTAC-MAT-2.

[0159] Exemplary insect vectors include pFastBacl, pFastBac DUAL, pFastBac ET, pFastBac HTa, pFastBac HTb, pFastBac HTc, pFastBac M30a, pFastBac M30b, pFastBac, M30c, pVL1392, pVL1393, pVL1393 M10, pVL1393M11, pVL1393 M12, a FLAG vector such as pPolh-FLAG1 or pPolh-MAT2, or a MAT vector such as pPolh-MAT1 or pPolh-MAT2.

[0160] In some cases, a yeast vector includes pDEST TM 14 vector, pDEST TM 15 vector, pDEST TM 17 vector, pDEST TM 24 vector, pYES-DEST52 vector, pBAD-DEST49 pAO815 Pichia vector, pFLD1 Pichia vector, pGAPZA, B, and C Pichia vector, pPIC3.5K Pichia vector, pPIC6A, B, and C Pichia vector, pPIC9K Pichia vector, pTEF1 / Zeo, pYES2 yeast vector, pYES2 / CT yeast vector, pYES 2 / NT A, B, and C yeast vector, or pYES 3 / CT yeast vector.

[0161] Exemplary algal vectors include pChlamy-4 vectors or MCS vectors.

[0162] Examples of mammalian vectors include transient expression vectors or stable expression vectors. Mammalian transient expression vectors can include pRK5, p3xFLAG-CMV 8, pFLAG-Myc-CMV 19, pFLAG-Myc-CMV 23, pFLAG-CMV 2, pFLAG-CMV 6a,b,c, pFLAG-CMV 5.1, pFLAG-CMV 5a,b,c, p3xFLAG-CMV 7.1, pFLAG-CMV 20, p3xFLAG-Myc-CMV 24, pCMV-FLAG-MAT1, pCMV-FLAG-MAT2, pBICEP-CMV 3, or pBICEP-CMV 4. Mammalian stable expression vectors can include pFLAG-CMV 3, p3xFLAG-CMV 9, p3xFLAG-CMV 13, pFLAG-Myc-CMV 21, p3xFLAG-Myc-CMV 25, pFLAG-CMV 4, p3xFLAG-CMV 10, p3xFLAG-CMV 14, pFLAG-Myc-CMV 22, p3xFLAG-Myc-CMV 26, pBICEP-CMV 1, or pBICEP-CMV 2.

[0163] In some cases, a cell-free system is a mixture of cytoplasmic and / or nuclear components from cells and is used for in vitro nucleic acid synthesis. In some cases, a cell-free system utilizes prokaryotic cell components or eukaryotic cell components. Sometimes, nucleic acid synthesis is obtained in a cell-free system based on Drosophila cells, Xenopus eggs, or HeLa cells. Exemplary cell-free systems include, but are not limited to, E. coli S30 extract systems, E. coli T7 S30 systems, or

[0164] Host cells

[0165] A host cell can be any suitable cell, such as a cell of natural origin or a genetically modified cell. In some cases, a host cell is a production host cell. In some cases, a host cell is a eukaryotic cell. In other cases, a host cell is a prokaryotic cell. In some cases, a eukaryotic cell includes a fungal (e.g., a yeast cell), an animal cell, or a plant cell. In some cases, a prokaryotic cell is a bacterial cell. Examples of bacterial cells include gram-positive bacteria or gram-negative bacteria. Sometimes a gram-negative bacteria is anaerobic, rod-shaped, or both.

[0166] In some cases, the gram-positive bacteria include Actinobacteria, Firmicutes, or Tenericutes. In some cases, the gram-negative bacteria include Aquificae, Deinococcus-Thermus, Fibrobacteres-Chlorobi / Bacteroidetes (FCB superphylum), Fusobacteria, Gemmatimonadetes, nitrospirae, Planctomycetes-Verrucomicrobia / Chlamydiae (PVC superphylum), Proteobacteria, Spirochaetes, or Synergistetes. Other bacteria can be Acidobacteria, Chloroflexi, Chrysiogenetes, Cyanobacteria, Deferribacteres, Dictyoglomi, Thermodesulfobacteria, or Thermotogae. The bacterial cell can be Escherichia coli, Clostridium botulinum, or Coli bacilli.

[0167] Exemplary prokaryotic host cells include, but are not limited to, BL21, Mach1 TM , DH10B TM , TOP10, DH5a, DH10Bac TM , OmniMax TM , MegaX TM , DH12S TM , INV110, TOP10F’, INVaF, TOP10 / P3, ccdB Survival, PIR1, PIR2, Stbl2 TM , Stbl3 TM , or Stbl4 TM .

[0168] In some cases, animal cells include cells from vertebrates or invertebrates. In some cases, animal cells include cells from marine invertebrates, fish, insects, amphibians, reptiles, or mammals. In some cases, fungal cells include yeast cells, such as beer yeast, bread yeast, or wine yeast.

[0169] Fungi include ascomycetes, such as yeasts, molds, filamentous fungi, basidiomycetes, or zygomycetes. In some cases, yeasts include Ascomycota or Basidiomycota. In some cases, Ascomycota includes Saccharomycotina (eukaryotic yeasts, e.g., Saccharomyces cerevisiae (baker’s yeast)) or Taphrinomycotina (e.g., Schizosaccharomycetes (fission yeasts)). In some cases, Basidiomycota includes Agaricomycotina (e.g., Tremellomycetes) or Pucciniomycotina (e.g., Microbotryomycetes).

[0170] Exemplary yeasts or filamentous fungi include, for example, the genera Saccharomyces, Schizosaccharomyces, Candida, Pichia, Hansenula, Kluyveromyces, Zygosaccharomyces, Yarrowia, Trichosporon, Rhodosporidi, Aspergillus, Fusarium, or Trichoderma. Exemplary yeasts or filamentous fungi include, for example, the following species: Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida utilis, Candida boidini, Candida albicans, Candida tropicalis, Candida stellatoidea, Candida glabrata, Candida krusei, Candida parapsilosis, Candida guilliermondii, Candida viswanathii, Candida lusitaniae, Rhodotorula mucilaginosa, Pichia metanolica, Pichia angusta, Pichia pastoris, and the like. pastoris), Pichia anomala, Hansenula polymorpha, Kluyveromyces lactis, Zygosaccharomyces rouxii, Yarrowia lipolytica, Trichosporon pullulans, Rhodosporidium toru-Aspergillus niger, Aspergillus nidulans, Aspergillus awamoriawamori, Aspergillus oryzae, Trichoderma reesei, Yarrowia lipolytica, Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii, Zygosaccharomyces bailii, Cryptococcus neoformans, Cryptococcus gattii, or Saccharomyces boulardii.

[0171] Exemplary yeast host cells include, but are not limited to, Pichia pastoris yeast strains such as GS115, KM71H, SMD1168, SMD1168H, and X-33; and Saccharomyces cerevisiae yeast strains such as INVSc1.

[0172] In some cases, the other animal cells include cells obtained from molluscs, arthropods, annelids, or sponges. In some cases, the other animal cells are mammalian cells, such as cells from primates, apes, horses, cattle, pigs, dogs, cats, or rodents. In some cases, rodents include mice, rats, hamsters, gerbils, hamsters, chinchillas, chipmunks, or guinea pigs.

[0173] Exemplary mammalian host cells include, but are not limited to, 293A cell line, 293FT cell line, 293F cells, 293H cells, CHO DG44 cells, CHO-S cells, CHO-K1 cells, FUT8 KO CHOK1, Expi293F TM cells, Flp-In TM T-REx TM 293 cell line, Flp-In TM -293 cell line, Flp-In TM -3T3 cell line, Flp-In TM -BHK cell line, Flp-In TM -CHO cell lines, Flp-In TM -CV-1 cell line, Flp-In TM -Jurkat cell line, FreeStyle TM 293-F cells, FreeStyle TM CHO-S cells, GripTiteTM 293 MSR cell line, GS-CHO cell line, HepaRG TM cell, T-REx TM Jurkat cell line, Per.C6 cell, T-REx TM - 293 cell line, T-REx TM - CHO cell line and T-REx TM - HeLa cell line.

[0174] In some cases, the mammalian host cell is a stable cell line, or a cell line that has integrated into its own genome the genetic material of interest and has the ability to express the product of the genetic material for many generations of cell division. In some cases, the mammalian host cell is a transient cell line, or a cell line that has not integrated into its own genome the genetic material of interest and does not have the ability to express the product of the genetic material for many generations of cell division.

[0175] Exemplary insect host cells include, but are not limited to, Drosophila S2 cells, Sf9 cells, Sf21 cells, High Five TM cells and cells.

[0176] In some cases, the plant cell includes a cell from an alga. Exemplary insect cell lines include, but are not limited to, strains from Chlamydomonas reinhardtii 137c or Synechococcus elongatus PPC 7942.

[0177] Methods of treatment

[0178] In an aspect, provided herein are methods of treating cancer by administering an anti-CD46 antibody or immunoconjugate described herein.

[0179] In some embodiments, the cancer is multiple myeloma. In some embodiments, the cancer is relapsed multiple myeloma. In some embodiments, the cancer is remissive multiple myeloma. In some embodiments, the cancer is relapsed or remissive multiple myeloma.

[0180] In some embodiments, the cancer is prostate cancer. In some embodiments, the cancer is castration-resistant prostate cancer. In some embodiments, the cancer is metastatic prostate cancer.

[0181] In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein for use as a medicament. In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein for use in treating a disease, particularly for use in treating cancer. In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein for use in a method of treating cancer. In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein for use in treating a disease in an individual in need thereof. In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein for use in a method of treating an individual having cancer, the method comprising administering to the individual a therapeutically effective amount of an anti-CD46 antibody or immunoconjugate described herein. In one aspect, provided herein is an anti-CD46 antibody or immunoconjugate described herein before for the manufacture or preparation of a medicament for treating a disease in an individual in need thereof. In one aspect, provided herein is a medicament for use in a method of treating cancer, the method comprising administering to an individual having cancer a therapeutically effective amount of the medicament.

[0182] Dosage and Administration

[0183] For use in therapeutic methods, the anti-CD46 antibodies or immunoconjugates described herein can be formulated, dosed, and administered in a fashion consistent with good medical practice. Factors for consideration in this context include the particular disorder being treated, the particular mammal being treated, the clinical condition of the individual patient, the cause of the disorder, the part of the body to be treated, the method of administration, the scheduling of administration, and other factors known to medical practitioners. The anti-CD46 antibodies or immunoconjugates need not be, but can be, formulated with an

[0184] In some embodiments, the antibody or immunoconjugate described herein is administered to a human subject via intravenous infusion. In some embodiments, the antibody or immunoconjugate is administered to a human subject every 7 days, every 14 days, every 18 days, every 21 days, or every 30 days. In some embodiments, the antibody or immunoconjugate is administered to a human subject every 21 days.

[0185] In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.0 to about 5.0 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.0 to about 4.5 mg / kg, about 1.0 to about 4.0 mg / kg, about 1.0 to about 3.5 mg / kg, about 1.0 to about 3.0 mg / kg, about 1.0 to about 2.7 mg / kg, about 1.0 to about 2.5 mg / kg, about 1.0 to about 2.4 mg / kg, about 1.5 to about 4.5 mg / kg, about 1.5 to about 4.0 mg / kg, about 1.5 to about 3.5 mg / kg, about 1.5 to about 3.0 mg / kg, about 1.5 to about 2.7 mg / kg, about 1.5 to about 2.5 mg / kg, about 1.5 to about 2.4 mg / kg, about 1.5 to about 2.0 mg / kg, about 1.8 to about 4.5 mg / kg, about 1.8 to about 4.0 mg / kg, about 1.8 to about 3.5 mg / kg, about 1.8 to about 3.0 mg / kg, about 1.8 to about 2.7 mg / kg, about 1.8 to about 2.5 mg / kg, about 1.8 to about 2.4 mg / kg, or about 1.8 to about 2.0 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.5 to about 2.5 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.2 to about 3.0 mg / kg.

[0186] In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, or about 4.0 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.8, about 2.4, about 2.7, about 3.0, or about 3.2 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.8 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 2.4 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 2.7 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 3.0 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 3.2 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 1.5 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 2.5 mg / kg. In some embodiments, the antibody or immunoconjugate is administered to a human subject at a dose of about 3.0 mg / kg. In some embodiments, the weight is measured in kg. In some embodiments, the weight of the human subject is actual body weight. In some embodiments, the weight is measured in kg. In some embodiments, the weight of the human subject is adjusted body weight (AJBW).

[0187] Assaying CD46 expression

[0188] In one aspect, provided herein are methods of treating a cancer in a subject by (1) determining that the cancer comprises CD46, and (2) administering an anti-CD46 antibody or immunoconjugate described herein. In some embodiments, the cancer expressing CD46 is susceptible to treatment with the anti-CD46 antibody or immunoconjugate. In some embodiments, the anti-CD46 antibody or immunoconjugate is a more effective anti-cancer agent when the cancer expresses CD46 or expresses a higher level of CD46 than a non-cancer control. In some embodiments, the non-cancer control is a matched non-cancer control tissue from the subject or a cancer-free individual. For example, if the cancer is a prostate cancer, the non-cancer control tissue can be a healthy prostate.

[0189] In some embodiments, an anti-CD46 antibody is used to determine CD46 expression in a cancer. CD46 expression in a cancer (e.g., cancer cell, cancerous lesion, metastatic cell) can be detected by various methods, such as immunofluorescence microscopy, immunohistochemistry, or flow cytometry.

[0190] In another embodiment, the copy number of the CD46 gene in a cancer is determined. The CD46 gene is located on the q arm of chromosome 1 band 32 (1q32). In some embodiments, 1q amplification indicates higher CD46 expression. In some embodiments, the 1q amplification includes amplification of 1q32. In some embodiments, the 1q amplification includes amplification of 1q21, and amplification of 1q32 is inferred from amplification of 1q21. In some embodiments, the gene amplification includes an increase in the copy number of the CD46 gene. In some embodiments, the copy number of the CD46 gene is 3 or more. In some embodiments, the copy number of the CD46 gene is 4, 5, 6, 7, or 8.

[0191] Pharmaceutical compositions and formulations

[0192] In a further aspect, the present application provides a pharmaceutical composition comprising an anti-CD46 antibody or immunoconjugate described herein, e.g., for use in any of the above therapeutic methods. In one embodiment, the pharmaceutical composition comprises an anti-CD46 antibody or immunoconjugate provided herein and at least one pharmaceutically acceptable excipient. The preparation of pharmaceutical compositions that contain an anti-CD46 antibody or immunoconjugate described herein is known to those of skill in the art in light of the present disclosure, as exemplified by Remington's Pharmaceutical Sciences, 18th Ed., Mack Printing Company, 1990, incorporated herein by reference.

[0193] In some embodiments, the pharmaceutical composition comprises a buffer. In some embodiments, the buffer comprises histidine. In some embodiments, the pharmaceutical composition comprises about 10 mM to about 40 mM, about 10 mM to about 30 mM, or about 10 mM to about 20 mM histidine buffer. In some embodiments, the pharmaceutical composition comprises about 10 mM, about 15 mM, about 20 mM, about 25 mM, about 30 mM, about 35 mM, or about 40 mM histidine buffer. In some embodiments, the pharmaceutical composition comprises about 20 mM histidine buffer.

[0194] In some embodiments, the pharmaceutical composition comprises a cryoprotectant. In some embodiments, the cryoprotectant comprises a sugar. In some embodiments, the cryoprotectant comprises sucrose or trehalose. In some embodiments, the cryoprotectant comprises sucrose. In some embodiments, the pharmaceutical composition comprises about 4% to about 12%, about 4% to about 11%, about 4% to about 10%, about 4% to about 9%, about 4% to about 8%, about 5% to about 12%, about 5% or about 11%, about 5% to about 10%, about 5% or about 9%, about 5% to about 8%, about 6% to about 12%, about 6% to about 11%, about 6% to 10%, about 6% to about 9%, about 6% to about 8%, about 7% to about 12%, about 7% to about 11%, about 7% to about 10%, about 7% to about 9%, or about 7% to about 8% sucrose. In some embodiments, the pharmaceutical composition comprises about 8% sucrose.

[0195] In some embodiments, the pharmaceutical composition comprises a stabilizer. In some embodiments, the stabilizer prevents denaturation of the recombinant antibody, prevents aggregation of the immunoconjugate, or both. In some embodiments, the stabilizer is a polysorbate. In some embodiments, the stabilizer is polysorbate 20. In some embodiments, the stabilizer is polysorbate 80. In some embodiments, the pharmaceutical composition comprises about 0.001% to 0.1%, 0.001% to 0.05%, 0.001% to 0.04%, 0.001% to 0.03%, 0.001 to 0.02%, or 0.001% to 0.01% polysorbate (e.g., polysorbate 80). In some embodiments, the pharmaceutical composition comprises about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1% polysorbate (e.g., polysorbate 80). In some embodiments, the pharmaceutical composition comprises about 0.01% polysorbate (e.g., polysorbate 80).

[0196] In some embodiments, the pharmaceutical composition has a pH of about 5.0 to about 7.0. In some embodiments, the pharmaceutical composition has a pH of about 5.0, 5.5, 6.0, 6.5, 7.0, or 7.5. In some embodiments, the pharmaceutical composition has a pH of about 6.0.

[0197] In some embodiments, the pharmaceutical composition comprises an anti-CD46 antibody or immunoconjugate described herein at a concentration of about 5.0 mg / ml to 15.0 mg / ml, 5.0 mg / ml to 14.0 mg / ml, 5.0 mg / ml to 13.0 mg / ml, 5.0 mg / ml to 12.0 mg / ml, 5.0 mg / ml to 11.0 mg / ml, 5.0 mg / ml to 10.0 mg / ml, 6.0 mg / ml to 15.0 mg / ml, 7.0 mg / ml to 15.0 mg / ml, 8.0 mg / ml to 15.0 mg / ml, 9.0 mg / ml to 15.0 mg / ml, or 10.0 mg / ml to 15.0 mg / ml. In some embodiments, the pharmaceutical composition comprises an anti-CD46 antibody or immunoconjugate described herein at a concentration of about 5.0 mg / ml, 6.0 mg / ml, 7.0 mg / ml, 8.0 g / ml, 9.0 mg / ml, 10.0 mg / ml, 11.0 mg / ml, 12.0 mg / ml, 13.0 mg / ml, 14.0 mg / ml, or 15.0 mg / ml. In some embodiments, the pharmaceutical composition comprises an anti-CD46 antibody or immunoconjugate described herein at a concentration of about 5.0 mg / ml ± 1.0 mg / mL, 6.0 mg / ml ± 1.0 mg / mL, 7.0 mg / ml ± 1.0 mg / mL, 8.0 mg / ml ± 1.0 mg / mL, 9.0 mg / ml ± 1.0 mg / mL, 10.0 ± 1.0 mg / mL, 11.0 mg / ml ± 1.0 mg / mL, 12.0 mg / ml ± 1.0 mg / mL, 13.0 mg / ml ± 1.0 mg / mL, 14.0 mg / ml ± 1.0 mg / mL, or 15.0 mg / ml ± 1.0 mg / mL. In some embodiments, the pharmaceutical composition comprises an anti-CD46 antibody or immunoconjugate described herein at a concentration of about 10.0 ± 1.0 mg / mL.

[0198] Exemplary Formulations

[0199] An exemplary formulation of an anti-CD46 antibody or immunoconjugate described herein comprises an anti-CD46 antibody or immunoconjugate described herein at a concentration of about 10.0 mg / ml ± 1.0 mg / mL; about 20 mM histidine buffer, about 8.0% sucrose, about 0.01% polysorbate 80, at a pH of 6.0.

[0200] Articles of manufacture

[0201] In another aspect of the application, an article of manufacture containing materials useful for the treatment of the above-mentioned cancers is provided. The article of manufacture includes a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, IV solution bags, etc. The containers can be formed from a variety of materials such as glass or plastic. The container holds a composition, which is by itself or combined with another composition effective to treat a condition and can have a sterile access port (for example, the container can be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle).

[0202] The label or package insert indicates that the composition is used for treating the condition of choice. In addition, the article of manufacture can comprise (a) a first container wherein

[0203] Alternatively, or additionally, the article of manufacture can further comprise a second (or third) container comprising a pharmaceutically-acceptable buffer, such as bacteriostatic water for injection (BWFI), phosphate-buffered saline, Ringer's solution and dextrose solution. It can further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, and syringes.

[0204] Examples

[0205] These examples are for illustrative purposes only and are not meant to limit the scope of the claims provided herein.

[0206] Example 1: Binding of YS5FL to the surface of cancer cells

[0207] Cell surface CD46 was detected by flow cytometry. Cells were harvested, centrifuged and resuspended in FACS buffer (PBS + 2% FBS) at a concentration of 1 x 10 6 Cells were washed three times with FACS buffer. After the third wash, cells were resuspended in 100 μL of 1 :500 diluted Alexa Fluor-488 mouse anti-human IgGl Fc secondary antibody and incubated for 1 hour at 4°C in the dark. Cells were washed three times with 200 μL PBS by centrifugation at 2000 RPM for 5 minutes. After the last wash, cells were resuspended in 300 μL cold PBS and analyzed on a FACSVerse TMwere analyzed on a BD Biosciences) flow cytometer. YS5FL specifically bound to the surface of LnCap-C4-2B, LnCap-C4, DU145, PC3-Luc and Hs27 prostate cancer cells, but not to the non-tumor BPH1 cells FIG. 1 ). Likewise, YS5FL specifically bound to the surface of RPMI8226, MM.1S, MM.1R and INA6 multiple myeloma cells FIG. 2 ).

[0208] Example 2: Preparation of FOR46 immunoconjugate

[0209] The structure of YS5FL conjugated to the MMAE effector via the mc-vc-PAB linker is shown in FIG. 3 Purified YS5FL mAb (10 mg / ml) was adjusted to pH 6.8 with sodium phosphate buffer and then treated with TCEP (TCEP / mAb ratio of 2.1) for two hours at 22°C. The reduced mAb was reacted with mc-vc-PAB-MMAE (drug / mAb ratio of 6) in 9% dimethylacetamide for 15 minutes. The mAb was reduced a second time for one hour, conjugated a second time for 60 minutes, and the reaction was quenched by lowering the pH to 5.0 with 1 M acetic acid to yield the FOR46 immunoconjugate, which had a drug to antibody ratio of about 3.7 as determined by hydrophobic interaction chromatography FIG. 4 ).

[0210] Example 3: FOR46 drug product

[0211] The FOR46 immunoconjugate was formulated into a drug product to enable administration to human subjects. The formulation contained 10.0 ± 1.0 mg / mL FOR46 drug substance; 20 mM L-histidine buffer, 8.0% (w / v) sucrose and 0.01% (w / v) polysorbate 80, at pH 6.0. The formulation was determined to provide adequate stability (to prevent denaturation of the antibody and to prevent aggregation), buffering and cryoprotection to enable storage at -20°C. After storage at 5°C for 1 month, the formulation retained >90% binding potency and cell-based activity; >90% monomer; residual MMAE < 15 μg / mL; and was essentially free of visible particles.

[0212] Example 4: Dose escalation study - treatment of metastatic castration-resistant prostate cancer using FOR46

[0213] A dose escalation clinical trial is ongoing to determine the maximum tolerated dose (or maximum tested dose) of FOR46 in human subjects with metastatic castration-resistant prostate cancer (mCRPC), including treatment-related small cell / neuroendocrine prostate cancer (TSCNC). Eligible patients have disease progression after use of one or more androgen signaling inhibitors, exhibit maintained castrate testosterone levels (<50 ng / dL); and exhibit organ function as defined by: hemoglobin (Hgb) > 8 g / dL, absolute neutrophil count (ANC) > 1500 / μL; platelets (Plt) > 100 k; aspartate aminotransferase to alanine aminotransferase ratio (ALT / AST) < 2.5 x upper limit of normal (ULN); bilirubin (Bili) < 1.5 mg / dL; creatinine < 1.5 x ULN. Prior chemotherapy for mCRPC is not allowed. Eligible patients receive or are expected to receive intravenous infusions of FOR46 every 21 days. Thirty-three subjects are enrolled at 10 dose levels of 0.1 to 3.0 mg / kg. Median age is 66 years (range 42-81 years); median baseline PSA is 41 (range 0.2-1627); 7 subjects have visceral organ metastases. Patient demographics are shown in Table 7.

[0214] Table 7. Demographics of prostate cancer dose escalation trial patients.

[0215]

[0216] Accelerated titration using a 3+3 dose escalation design. Dose was changed from actual body weight to adjusted body weight after excessive toxicities (neutropenia and fatigue) occurred in subjects with high body mass index (BMI). G-CSF secondary prophylaxis was applied to subjects who experienced grade > 3 neutropenia in a prior treatment cycle. Treatment was continued if the investigator determined there was potential clinical benefit in the absence of excessive toxicity. A 50% reduction in serum prostate specific antigen (PSA) level provided preliminary objective evidence of response to treatment.

[0217] 33 subjects were divided into 10 cohorts, receiving different doses. Table 8 summarizes the cohorts and patient status. Table 9 summarizes the reduction in PSA and tumor burden. At 1.2 mg / kg or higher (n=24), 9 subjects (38%) had a 50% reduction in PSA (PSA50 response) and 15 subjects (63%) had any reduction in PSA. In 8 subjects with measurable disease, 3 objective partial responses (PR) were reported, 6 had stable disease, lasting from 9 to 39 weeks, as determined by RECIST criteria (Eisenhauer et al., New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1), European Journal of Cancer 45 (2009) 228-249). The median number of treatment cycles was 6 (range 1-28), of which 11 were ongoing.

[0218] Tables 10-16 list the PSA levels and RECIST results for cohorts 4-10, respectively, after each infusion cycle. FIG. 6 Results for all patients are summarized in Table 18.

[0219] Patient 12 had the most reduction in tumor burden. A CT scan after 2.7 mg / kg treatment for three cycles showed complete shrinkage of the largest tumor FIG. 5A ). The sum of the largest diameters (SLD) of the target lesions, including lung nodules and peri-rectal soft tissue mass, decreased from 5.7 cm at baseline to 2.0 cm after cycle 6 (65% reduction). This was accompanied by a 71% reduction in serum PSA and reduction of non-target lesions including RP lymph nodes FIG. 5B

[0220] Neutropenia was analyzed by determining absolute neutrophil count (ANC), as shown in Table 17. Of the 16 patients who received at least 1.8 mg / kg FOR46 treatment, 12 patients had grade 2 or higher neutropenia.

[0221]

[0222]

[0223]

[0224]

[0225]

[0226] ​

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235] Dose-limiting toxicity was grade 4 neutropenia in 3 of 3 high body mass index (BMI) subjects dosed at 2.4 mg / kg actual body weight and in 2 of 3 subjects dosed at 3.0 mg / kg adjusted body weight. The maximum tolerated dose (MTD) was 2.7 mg / kg adjusted body weight (AJBW). The most common related adverse events were grade 4 neutropenia in 11 of 33 (33%) subjects, grade 3 neutropenia in 6 (18%), infusion-related reactions (IRRs) in 14 (42%), of which 1 was grade 3, and neuropathy of any grade in 7 subjects (21%), of which 1 was grade 3. The most common adverse events are shown in Table 18.

[0236] Table 18. Adverse events observed in at least two prostate cancer subjects treated with FOR46.

[0237]

[0238]

[0239] A dose expansion study in prostate cancer subjects has been initiated. CD46 expression was determined by immunofluorescence microscopy at the time of enrollment. Three patients with moderate or strong positive CD46 expression were enrolled. A fourth subject with negative CD46 expression was not enrolled.

[0240] This example demonstrates that FOR46 has an acceptable toxicity profile using an adjusted body weight dose and provides encouraging preliminary evidence of efficacy in androgen signaling pathway inhibitor-resistant mCRPC subjects. FOR46 is currently being evaluated in two mCRPC expansion cohorts: adenocarcinoma and t-SCNC.

[0241] Example 5: Dose escalation study - treatment of relapsed or refractory multiple myeloma using FOR46

[0242] A dose escalation clinical trial of FOR46 drug product treatment of human subjects with relapsed or refractory multiple myeloma is ongoing. To be eligible, patients must have prior treatment with a proteasome inhibitor, an immunomodulatory imide drug (ImiD), and a CD38-directed therapy. Eligible patients also have the following organ function criteria: hemoglobin > 8 g / dL, ANC > 1500 / μL; platelets > 100 k; ALT / AST < 2.5 x upper limit of normal (ULN); bilirubin < 1.5 mg / dL; creatinine < 1.5 x ULN. FOR46 is administered once every three weeks, as an IV infusion over 30-60 minutes, with prophylaxis for infusion-related reactions.

[0243] The highest dose of the initial regimen is 2.4 mg / kg actual body weight. When the adjusted body weight dose is not used to define the MTD, escalation should be maintained until the modified regimen is amended to allow higher doses.

[0244] A clinical dose expansion trial of FOR46 at 2.4 mg / kg adjusted body weight is also ongoing in 10 patients. The eligibility criteria for the dose expansion trial are the same as for the dose escalation trial, except for ANC > 1000 / μL and platelets > 75 k.

[0245] In the dose escalation trial, fifteen subjects were enrolled at six pre-defined dose levels of 0.1 to 2.4 mg / kg, with 1 patient each at 0.1 mg / kg, 0.3 mg / kg, and 0.6 mg / kg, 3 patients each at 1.2 mg / kg and 1.8 mg / kg, and 6 patients at 2.4 mg / kg. The median age was 68 years (range 33-79), with 4 females. Nine patients had 1q gain, 5 patients did not, and 1 patient was unknown. The median number of prior treatment lines was 6 (range 3-17). The doses for the dose escalation and dose expansion trials are shown in Table 19. Patient characteristics are shown in Tables 20 and 21.

[0246] Table 19. Doses for the dose escalation and dose expansion trials of FOR46 treatment of relapsed or refractory multiple myeloma

[0247] Dose levels (mg / kg q 3 weeks) N(25) 0.1 1 0.3 1 0.6 1 1.2 3 1.8 3 2.4 (escalation - actual / AJBW dose) 6(3 / 3) 2.4 (extension - AJBW) 10

[0248] Table 20. Demographics of subjects in the dose escalation and dose expansion trials of FOR46 treatment of relapsed or refractory multiple myeloma

[0249]

[0250]

[0251] Table 21. Prior treatment of subjects in the dose escalation and dose expansion trial of FOR46 for relapsed or refractory multiple myeloma

[0252] Prior therapy, n (%) Escalation (n=15) and extension (n=10) Median (range) 8(3-19) Received >5 lines of therapy 21(84) Proteasome inhibitors, received / refractory 25(100) / 21(84) IMiDs, received / refractory 25(100) / 22(88) Pomalidomide, received / refractory 20(80) / 18(72) Anti-CD38 therapy, received / refractory 25(100) / 23(92) Carfilzomib, received / refractory 23(92) / 23(92)

[0253] In the dose escalation trial, an accelerated titration following a 3+3 dose escalation design was ongoing. FOR46 was infused intravenously over 30-60 minutes on Day 1 of a 21 -day cycle at the dose specified in the protocol. After excessive toxicities (neutropenia and fatigue) occurred in subjects with high body mass index (BMI), the dose was changed from actual body weight (AW) to adjusted body weight (AJBW). In previous treatment cycles, subjects who experienced Grade >3 neutropenia received G-CSF secondary prophylaxis.

[0254] Safety was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Dexamethasone was used only for prophylaxis of infusion reactions. CD46 antigen density on patient MM cells was determined via flow cytometry. Therapeutic efficacy was monitored by measuring immunoglobulin levels (M-protein) in serum or urine, including IgA, lambda light chain (l), kappa light chain (k), and M-spike protein.

[0255] The only dose-limiting toxicity was Grade 4 neutropenia in 1 high BMI patient dosed on AW. This was the only dose-limiting toxicity in 6 patients dosed at 2.4 mg / kg on a mix of AW (n=3) and ABW (n=3). At the 2.4 mg / kg AJBW dose, 1 of 3 experienced non-dose-limiting Grade 4 neutropenia. The most common related adverse events were Grade 4 neutropenia in 3 patients (20%). One patient (6.7%) experienced Grade 4 thrombocytopenia, and 1 patient (6.7%) experienced Grade 3 AST elevation, neutropenia, anemia, nausea, and peripheral neuropathy (PN). Adverse events are shown in Table 22.

[0256] Table 22. Adverse events of subjects in the dose escalation and dose expansion trial of FOR46 for relapsed or refractory multiple myeloma

[0257]

[0258]

[0259] In the initial evaluation, all patients administered FOR46 at doses less than 1.8 mg / kg (i.e., 0.1 mg / kg, 0.3 mg / kg, 0.6 mg / kg, and 1.2 mg / kg) were terminated from treatment due to disease progression. Patients in the 1.8 mg / kg cohort have been initiated on treatment. Patient 8 responded to FOR46 treatment with reductions in serum IgG, serum kappa light chains, serum lambda light chains, and urine M-spike protein. This response provides preliminary evidence of anti-tumor activity at the 1.8 mg / kg dose.

[0260] According to IMWG criteria (BGM Durie et al., International uniform response criteria for multiple myeloma. Leukemia (2006) 1-7), four patients responded to FOR46 with partial remission (PR). See Table 23.

[0261] Table 23. Multiple myeloma patients who responded to FOR46

[0262]

[0263]

[0264] Of the 6 response-evaluable patients in the 1.8 and 2.4 mg / kg dose escalation cohorts, 3 had partial responses (PR) that lasted 21 weeks, 30 weeks, and 15 weeks, respectively. Of the PRs, one patient did not have a 1q21 gain. In the dose expansion, 3 of 10 patients were not evaluable. Of the seven evaluable patients, one patient had a PR that lasted 18 weeks and was discontinued at partial response due to an adverse event of peripheral neuropathy. Two patients had stable disease for 3 and 6 cycles. Four patients had best responses of progressive disease.

[0265] Patient 006-05-008 received treatment with 1.8 mg / kg FOR46. The patient was a 62-year-old white male diagnosed with IgG kappa MM in July 2009. The patient was 1q gain negative and had received the following treatments: (1) daratumumab, pomalidomide, and dexamethasone; (2) pomalidomide and dexamethasone; (3) lenalidomide; (4) lenalidomide and bortezomib; and (5) Carfilzomib and pomalidomide. IgG, kappa light chain, and serum M-spike protein results are shown in Table 24. FIG. 7A

[0266] ​Patient 001-06-012 received treatment with 2.4 mg / kg FOR46. This patient was a 70-year-old Caucasian male diagnosed with IgAK MM in January 2013, who was 1q gain positive, and had received the following prior treatments: (1) cyclophosphamide, bortezomib, and dexamethasone; (2) lenalidomide, bortezomib, and dexamethasone; (3) carfilzomib, cyclophosphamide, and dexamethasone; and (4) daratumumab, pomalidomide, and dexamethasone. IgA, kappa light chain, and serum M spike protein results are shown in Table 1. FIG. 7B

[0267] Patient 003-06-014 received treatment with 2.4 mg / kg (AJBW) FOR46. This patient was a 56-year-old male diagnosed with IgAK myeloma in December 2015. The patient was 1q21 gain positive, and had received the following prior treatments: (1) cyclophosphamide, bortezomib, and dexamethasone; (2) carfilzomib, lenalidomide, dexamethasone, melphalan, and ASCT, with ixazomib maintenance; (3) carfilzomib, daratumumab, and dexamethasone; and (4) CAR-T clinical trial. IgA, kappa light chain, and urine M spike protein results are shown in Table 2. FIG. 7C

[0268] Results for all patients in the dose escalation trial are shown in Table 24. Results for all patients in the dose expansion trial are shown in Table 25. FIG. 8 DEFINITIONS Anti-CD46 recombinant antibodies Effector agents Immunoconjugates Production of antibodies or antigen-binding fragments thereof Expression vectors Host cells Methods of treatment Assaying CD46 expression Pharmaceutical compositions and formulations Articles of manufacture FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 6 FIG. 5A FIG. 5B Dose levels (mg / kg q 3 weeks) 2.4 (escalation - actual / AJBW dose) 2.4 (extension - AJBW) Prior therapy, n (%) Escalation (n=15) and extension (n=10) Median (range) Received >5 lines of therapy Proteasome inhibitors, received / refractory IMiDs, received / refractory Pomalidomide, received / refractory Anti-CD38 therapy, received / refractory Carfilzomib, received / refractory FIG. 7A FIG. 7B FIG. 7C FIG. 8 DEFINITIONS Anti-CD46 recombinant Results from both trials are summarized in Table 26.

[0269] In summary, FOR46 demonstrated an acceptable toxicity profile using a weight-adjusted dose. There is encouraging evidence of efficacy in triple refractory multiple myeloma. The dose escalation trial will be expanded to 2.7 mg / kg, adjusted for body weight.

[0270]

[0271]

[0272]

[0273]

[0274]

[0275]

[0276]

[0277]

[0278] ​​

[0279]

[0280]

[0281]

[0282] Example 6: Formulation of FOR46

[0283] The objective of this study was to develop an optimized formulation of FOR46. During the formulation development process, a thermal stability study, a freeze-thaw stability study and a stirring study were performed. The stability of the drug product was evaluated by assays including overall appearance, protein concentration, pH, as well as SEC-HPLC, cIEF, Caliper-SDS_R / NR and MFI analysis to select the best formulation.

[0284] Analytical methods

[0285] Appearance

[0286] The appearance of all samples was checked using a YB-2 light box against a black and white background, including clarity, color and visible particles.

[0287] pH

[0288] The pH of the samples was measured using a Seven Multi S4.0 pH meter with a microelectrode. The pH meter was calibrated before each use. Protein concentration

[0289] The protein concentration was determined by UV280 reading using a NanoDrop 2000 spectrophotometer. The extinction coefficient used for all the evaluation studies was 1.571 AU*mL*mg-L*cm-1. All measurements were repeated twice, using 2.5 μL of sample each time, and the average results were reported.

[0290] SEC-HPLC

[0291] Size exclusion chromatography was performed using an Agilent 1260 Infinity system and a TSK Gel G3000SWXL size exclusion column (300 x 7.8 mm, 5 gm) at 25 °C. The flow rate was set at 1.0 mL / min in isocratic gradient. For each sample, the mobile phase consisted of 50 mM sodium phosphate buffer, 300 mM NaCl, pH 6.8 ± 0.1. A loading of 100 μg was injected and detected at a wavelength of 280 nm with a UV detector. Data were analyzed using Waters Empower.

[0292] SEC-HPLC

[0293] cIEF

[0294] cIEF was performed on a ProteinSimple iCE3 instrument with FC-coated cIEF cartridges. During the formulation development phase, 50 pg of each sample was mixed with 100 11L of master mix consisting of pi marker 4.22 / 7.46, Servalyt 2-9, Servalyt 3-5, 1% Methylcellulose solution, and 8M Urea solution. After mixing, samples were focused for 1 min at 1500V and 8 min at 3000V. The detection wavelength was set to 280 nm to evaluate the charge variant profile across different pi ranges. In the forced degradation study, the pi marker in the master mix was changed to 4.22 / 7.05.

[0295] Caliper-SDS_R&NR

[0296] Prior to testing the samples, a pre-treatment was required, such as incubation at 70°C for 10 min with sample buffer, SDS and N-ethylmaleimide (for non-reduced or NR) or dithiothreitol (for reduced or R). The loading mix of minimum volume of 42 pL (final protein concentration of 0.045 mg / mL) was then tested by LabChip GXII Touch at excitation / emission wavelengths of 635 nm and 700 nm. The final results were analyzed by the commercial software LabChip GX Reviewer.

[0297] CE-SDS_R / NR

[0298] Non-reduced CE-SDS was performed using a Beckman Coulter PA800 Enhanced or PA800 Plus instrument equipped with a photodiode array detector. Samples were diluted to 4 mg / mL with dilution solution (PB-CA) and then heated at 60°C for 10 min in the presence of 75 pL SDS sample buffer and 5 pL of 100 mM NEM for non-reduced CE-SDS. Samples were injected at +5 kV for 15 s and then separated at +11 kV for 30 min. Detection was performed at 220 nm.

[0299] DSC analysis

[0300] DSC analysis was performed by a MicroCal™ VP-Capillary DSC system from GE Healthcare, model AS12-001C. Prior to analysis, the protein sample was first diluted to 1 mg / mL with the formulation buffer. 300 μL of the test protein sample was added to a 96-well plate, and 300 μL of its corresponding buffer was added as a reference. The samples were heated from 10 °C to 110 °C at a heating rate of 200 °C / h in the capillary DSC system. Two tests were performed for each sample, and the DSC results (Tm onset and Tm values) were analyzed with the Origin 7.0 DSC auto-analysis software.

[0301] 3. Excipient screening

[0302] 3.1 Purpose of the study

[0303] The purpose of this study was to evaluate the effect of NaCl, Arg-HCl, sucrose and trehalose on the stability of FOR46 in selected buffers.

[0304] 3.2 Study parameters

[0305] FOR46 was formulated at a concentration of 10 mg / mL in 20 mM histidine buffer, pH 6.0. For each formulation, 140 mM NaCl, 150 mM Arg-HCl, 8% (w / v) sucrose or trehalose were added as stabilizers, respectively, and no addition was set as a blank, as shown in Table 26.

[0306] The samples in each formulation were subjected to a maximum of five cycles of freeze / thaw stress and thermal stress (40 °C and 25 °C). The stability of FOR46 in each formulation was evaluated with different assays given in Table 26.

[0307] Table 26. Formulation options.

[0308]

[0309] Table 27. Stability study plan for excipient screening

[0310]

[0311]

[0312] X = appearance, pH, protein concentration, SEC-HPLC, cIEF, Caliper-SDS, DAR 3.4 Sample preparation

[0313] The buffer of FOR46 was exchanged to 20 mM histidine, pH 6.0 via ultrafiltration. After addition of appropriate amounts of sucrose, trehalose, Arg-HCl or NaCl, the protein concentration was adjusted to 10 mg / mL, and all samples were then sterile filtered using 0.22 pm PES membrane filters. For each formulation sample, eight (8) 2R glass vials were filled with 1 mL of the filtered DS. One (1) vial was subjected to three and five cycles of freeze-thaw stress, respectively. In each cycle, the freezing time was at least 12 hours in a freezer at -40 °C. The samples were thawed at room temperature. Three (3) vials were incubated at 40 °C. Two vials were incubated at 25 °C. One vial was withdrawn from each study condition at the designated time points for analysis. One (1) vial was used as TO.

[0314] 3.5 Results and Discussion

[0315] 3.5.1 Appearance, Protein Concentration and pH Results

[0316] After short-term storage at 5 °C, a significant precipitation was observed in F1 and F2, which could be attributed to the high ionic strength in the formulations. Therefore, FL and F2 were excluded from the study. At the beginning of the study, all remaining samples were colorless, slightly opalescent, and free of visible particles.

[0317] After incubation at 25 °C and 40 °C for up to 4 weeks, F5 was free of visible particles, while many particles were observed in both F3 and F4. This could be due to the higher surface tension of the sugar-containing formulations leading to protein denaturation, which could be eliminated by adding a surfactant to the final formulation.

[0318] After up to 5 cycles of freeze-thaw stress, no substantial changes in appearance were found in F3, F4 and F5.

[0319] After 40 °C, 25 °C and 5 cycles of freeze-thaw, no substantial changes in pH and protein concentration were found.

[0320] SEC Purity

[0321] SEC purity data are summarized in Table 28. According to the SEC data at 25 °C, no substantial changes were found for any of the samples after up to 5 cycles of freeze-thaw. After 4 weeks of incubation at 40 °C, the SEC purity of F5 was significantly lower than that of F3 and F4. Therefore, it can be concluded that the stabilizing effect of sucrose and trehalose on ADCs is unexpectedly significant and comparable.

[0322] Table 28. SEC purity results of FOR46 excipient screening study.

[0323]

[0324] Caliper-SDS_R / NR purity

[0325] No substantial changes in Caliper-SDS_R / NR purity were found in any of the samples after up to 5 freeze-thaw cycles and incubation at 25°C and 40°C for 4 weeks.

[0326] cIEF

[0327] Based on cIEF data, the purity of the main peak for all samples decreased significantly after incubation at 40°C and 25°C for 4 weeks, and the rate of decrease was comparable between F3-F5. No substantial changes were found after up to 5 freeze-thaw cycles.

[0328] Drug antibody ratio (DAR)

[0329] No substantial changes in DAR were found for all samples after incubation at 40°C and 25°C for 4 weeks and up to 5 freeze-thaw cycles.

[0330] Conclusion

[0331] Although a poorer appearance was observed in the buffer containing trehalose and sucrose, the adverse effect caused by higher surface tension can be reversed by adding a surfactant. Surprisingly, SEC purity results indicated that sucrose and trehalose exhibited outstanding and comparable performance in stabilizing FOR46 against thermal stress. Considering the commercial cost, sucrose was chosen as the excipient in the optimized formulation. The surfactant screening study will be conducted in 20 mM histidine buffer at pH 6.0 containing 8% (w / v) sucrose (F3).

[0332] 4. Surfactant screening

[0333] This study aimed to evaluate the stabilizing effect of 2 different surfactants (PS-80 and PS-20) at 3 content levels in 20 mM histidine buffer at pH 6.0 containing 8% (w / v) sucrose. Based on DAR data (shown in Table 34), no substantial changes in DAR were found for all samples after incubation at 40°C and 25°C for 4 weeks and up to 5 freeze-thaw cycles.

[0334] Study parameters

[0335] FOR46 was formulated at 10 mg / mL in 20 mM histidine buffer at pH 6.0 containing 8% (w / v) sucrose into 7 formulations as shown in Table 29. PS-80 or PS-20 was added to each formulation at 3 content levels, respectively, and a formulation without surfactant was included as a blank. Samples in each formulation were subjected to up to five freeze-thaw cycles, thermal stress (40°C), and agitation stress (300 rpm for 2 days). The stability of the ADC at the designated time points was evaluated with different methods.

[0336] Table 29. Formulation selection for FOR46 excipient screening

[0337]

[0338] Table 30. Formulation selection for FOR46 excipient screening

[0339]

[0340] X = appearance, pH, protein concentration SEC-HPLC, cIEF, SDS Caliper_R; Y = MFI; Z = antigen binding

[0341] 4.3 Drug Substance

[0342] Prior to the surfactant screening study, FOR46 formulated in 20 mM Histidine buffer, pH 6.0 containing 8% (w / v) sucrose was stored at 2-8 °C.

[0343] Sample Preparation

[0344] WBP2O95 ADC DS was sterile filtered using a 0.22 pm PES membrane filter after the addition of the designed amount of PS-80 or PS-20. For each formulation sample, eight (8) 2R glass vials were filled with 1 mL of the filtered DS, respectively. Two (2) vials were subjected to five freeze-thaw stress cycles. In each cycle, the freezing time was at least 12 hours in a freezer at -40 °C. The samples were thawed at room temperature. Two (2) vials were incubated at 40 °C. Two (2) vials were stirred at ambient temperature at a speed of 300 rpm for 2 days. At the designated time points, samples were taken from one vial at 40 °C and from both vials subjected to freeze-thaw stress and stirring stress for analysis. Two (2) vials were used as TO.

[0345] 4.5 Results and Discussion

[0346] 4.5.1 Appearance, Protein Concentration and pH Results

[0347] No significant changes in appearance were found for all samples after 5 freeze-thaw cycles. After stirring at 300 rpm for 2 days and incubation at 40 °C for 4 weeks, particles and fibers were observed in F1 (no surfactant). This indicates that the presence of surfactant is necessary for the protection of the ADC under heat and stirring stress conditions.

[0348] No substantial changes in pH and protein concentration were found.

[0349] 4.5.2 SEC Purity

[0350] No substantial change in SEC purity was found after 5 freeze-thaw cycles and agitation for 2 days. After incubation at 40 °C for 4 weeks, a 6% decrease in main peak purity was found in all 7 formulations. Based on SEC purity data, all formulations were comparable under all conditions.

[0351] 4.5.3 CE-SDS_R Purity

[0352] No substantial change in CE-SDS-R purity was found under heat stress, freeze-thaw, and agitation stress conditions.

[0353] 4.5.4 cIEF

[0354] No substantial change in cIEF was found after 5 freeze-thaw cycles and agitation for 2 days. Under heat stress, a significant decrease in main peak purity was found with a corresponding increase in acid peak purity. However, the changes were comparable between all formulations.

[0355] 4.5.5 Potency

[0356] Based on previous data, 3 of the guided formulations (F2, F3, and F4) were selected for binding potency determination. No substantial change in binding ability was found under heat stress, agitation stress, and freeze-thaw stress.

[0357] 4.5.6 MFI

[0358] Surprisingly, based on MFI results, more than 10-fold of particles were found in F1 compared to the rest of the formulations. There were more sub-visible particles in F1 compared to other formulations.

[0359] Table 31. MFI results of FOR46 in surfactant screening study.

[0360]

[0361]

[0362] 4.6 Conclusion

[0363] Based on appearance and MFI results, surfactants played an unexpectedly important role in protecting ADCs under heat and agitation stress conditions. However, no difference was found between 6 formulations with 2 different surfactants (PS-80 and PS-20) at 3 content levels. Considering the lower CMC (critical micelle concentration) of PS-80 than PS-20, this indicates that the effective concentration of surfactants is low, and the potential adverse effects introduced by the degradation of PS-80 at high content levels, 0.01% (w / v) PS-80 was selected in the final formulation.

[0364] FOR46 (10 mg / mL) in 20 mM histidine buffer, pH 6.0, containing 8% (w / v) sucrose and 0.01% (w / v) PS-80 was selected as the final formulation. SEQUENCE LISTING <110> Fortis Therapeutics, Inc. <120> Immunoconjugates targeting CD46 and methods of use thereof <130> 39442-708.201 <140> US 17 / 395,358 <141> 2021-08-05 <150> 63 / 062,740 <151> 2020-08-07 <160> 10 <170> PatentIn version 3.5 <210> 1 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic Peptide <220> <223> Synthetic antibody VH CDR1 domain <400> 1 Gly Leu Thr Val Asn Asn Tyr Ala 1 5 <210> 2 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic Peptide <220> <223> Synthetic antibody VH CDR2 domain <400> 2 Ile Ser Tyr Asp Gly Asn Asn Lys 1 5 <210> 3 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic peptide <220> <223> Synthetic antibody VH CDR3 domain <400> 3 Ala Lys Gly Gly Gly Tyr Phe Asp Leu 1 5 <210> 4 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic peptide <220> <223> Synthetic antibody VL CDR1 domain <400> 4 Ser Ser Asn Ile Gly Ala Gly Tyr Asp 1 5 <210> 5 <211> 3 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic peptide <220> <223> Synthetic antibody VL CDR2 domain <400> 5 Gly Asn Asn 1 <210> 6 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic peptide <220> <223> Synthetic antibody VL CDR3 domain <400> 6 Ser Ser Tyr Thr Ser Gly Thr Trp Leu 1 5 <210> 7 <211> 116 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic Polypeptide <220> <223> Synthetic antibody VH domain <400> 7 Gln Val Gln Leu Val Gln Ser Gly Gly Gly Val Val Gln Pro Gly Arg 1 5 10 15 Ser Leu Arg Leu Ala Cys Ala Ala Ser Gly Leu Thr Val Asn Asn Tyr 20 25 30 Ala Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 Ala Val Ile Ser Tyr Asp Gly Asn Asn Lys Tyr Tyr Ala Asp Ser Val 50 55 60 Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90 95 Ala Lys Gly Gly Gly Tyr Phe Asp Leu Trp Gly Arg Gly Thr Leu Val 100 105 110 Thr Val Ser Ser 115 <210> 8 <211> 109 <212> PRT <213> Artificial Sequence <220> <223> DESCRIPTION OF ARTIFACT: Synthetic Polypeptide <220> <223> SYNTHETIC ANTIBODY VL DOMAIN <400> 8 Gln Ser Val Leu Thr Gin Pro Pro Ser Val Ser Gly Ala Pro Gly Gin 1 5 10 15 Arg Val Thr lie Ser Cys Thr Gly Ser Ser Ser Asn lie Gly Ala Gly 20 25 30 Tyr Asp Val His Trp Tyr Gin Gin Leu Pro Gly Thr Ala Pro Lys Leu 35 40 45 Leu lie Tyr Gly Asn Asn Asn Arg Pro Ser Gly Val Pro Asp Arg Phe 50 55 60 Ser Gly Ser Lys Ser Gly Thr Ser Ala Ser Leu Ala lie Thr Gly Leu 65 70 75 80 Gln Ala Glu Asp Glu Ala Asp Tyr Tyr Cys Ser Ser Tyr Thr Ser Gly 85 90 95 Thr Trp Leu Phe Gly Gly Gly Thr Lys Leu Thr Val Leu 100 105 <210> 9 <211> 446 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequences: Synthetic Polypeptide <220> <223> Synthetic antibody H domain <400> 9 Gln Val Gln Leu Val Gln Ser Gly Gly Gly Val Val Gln Pro Gly Arg 1 5 10 15 Ser Leu Arg Leu Ala Cys Ala Ala Ser Gly Leu Thr Val Asn Asn Tyr 20 25 30 Ala Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 Ala Val Ile Ser Tyr Asp Gly Asn Asn Lys Tyr Tyr Ala Asp Ser Val 50 55 60 Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90 95 Ala Lys Gly Gly Gly Tyr Phe Asp Leu Trp Gly Arg Gly Thr Leu Val 100 105 110 Thr Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala 115 120 125 Pro Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu 130 135 140 Val Lys Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly 145 150 155 160 Ala Leu Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser 165 170 175 Gly Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu 180 185 190 Gly Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr 195 200 205 Lys Val Asp Lys Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr 210 215 220 Cys Pro Pro Cys Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe 225 230 235 240 Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro 245 250 255 Glu Val Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro Glu Val 260 265 270 Lys Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr 275 280 285 Lys Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val 290 295 300 Leu Thr Val Leu His Gin Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys 305 310 315 320 Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser 325 330 335 Lys Ala Lys Gly Gin Pro Arg Glu Pro Gin Val Tyr Thr Leu Pro Pro 340 345 350 Ser Arg Glu Glu Met Thr Lys Asn Gin Val Ser Leu Thr Cys Leu Val 355 360 365 Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly 370 375 380 Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp 385 390 395 400 Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp 405 410 415 Gln Gin Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu His 420 425 430 Asn His Tyr Thr Gin Lys Ser Leu Ser Leu Ser Pro Gly Lys 435 440 445 <210> 10 <211> 215 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequences: Synthetic Polypeptide <220> <223> Synthetic antibody L domain <400> 10 Gln Ser Val Leu Thr Gin Pro Pro Ser Val Ser Gly Ala Pro Gly Gin 1 5 10 15 Arg Val Thr lie Ser Cys Thr Gly Ser Ser Ser Asn lie Gly Ala Gly 20 25 30 Tyr Asp Val His Trp Tyr Gin Gin Leu Pro Gly Thr Ala Pro Lys Leu 35 40 45 Leu lie Tyr Gly Asn Asn Asn Arg Pro Ser Gly Val Pro Asp Arg Phe 50 55 60 Ser Gly Ser Lys Ser Gly Thr Ser Ala Ser Leu Ala lie Thr Gly Leu 65 70 75 80 Gln Ala Glu Asp Glu Ala Asp Tyr Tyr Cys Ser Ser Tyr Thr Ser Gly 85 90 95 Thr Trp Leu Phe Gly Gly Gly Thr Lys Leu Thr Val Leu Gly Gin Pro 100 105 110 Lys Ala Ala Pro Ser Val Thr Leu Phe Pro Pro Ser Ser Glu Glu Leu 115 120 125 Gln Ala Asn Lys Ala Thr Leu Val Cys Leu lie Ser Asp Phe Tyr Pro 115 120 125 Gln Ala Asn Lys Ala Thr Leu Val Cys Leu lie Ser Asp Phe Tyr Pro 130 135 140 Gly Ala Val Thr Val Ala Trp Lys Ala Asp Ser Ser Pro Val Lys Ala 145 150 155 160 Gly Val Glu Thr Thr Thr Pro Ser Lys Gln Ser Asn Asn Lys Tyr Ala 165 170 175 Ala Ser Ser Tyr Leu Ser Leu Thr Pro Glu Gln Trp Lys Ser His Arg 180 185 190 Ser Tyr Ser Cys Gln Val Thr His Glu Gly Ser Thr Val Glu Lys Thr 195 200 205 Val Ala Pro Thr Glu Cys Ser 210 215

Claims

1. A pharmaceutical composition comprising: Immunoconjugates, comprising: Recombinant antibodies, containing: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of adducts; wherein each of the one, two, three or four pairs of adducts comprises monomethyl auristatin E (MMAE) coupled to the recombinant antibody via a maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (mc-vc-PAB) linker; wherein each of the one, two, three or four pairs of adducts is coupled to a pair of cysteine ​​residues of the recombinant antibody, wherein the pair of cysteine ​​residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second heavy chain; and C228 of the first heavy chain and C228 of the second heavy chain; Buffer, which is 20 mM histidine and has a pH of about 6.0, Stabilizer, which is 0.01% polysorbate 80, and 8.0% sucrose. The pharmaceutical composition according to claim 1 , comprising two pairs of said adducts.

3. The pharmaceutical composition of claim 1, wherein the concentration of the immunoconjugate is 10.0 ± 1.0 mg / mL.

4. Use of the pharmaceutical composition according to claim 1 in the preparation of a medicament for treating cancer in a human subject comprising cells expressing CD46.

5. The use according to claim 4, wherein the cancer is relapsed or refractory multiple myeloma (RRMM).

6. The use according to claim 4, wherein the cancer is metastatic castration-resistant prostate cancer (mCRPC).

7. Use according to claim 4, wherein the cells comprise CD46 as determined by immunofluorescence microscopy or immunohistochemistry or by flow cytometry.

8. The use according to claim 4, wherein the cell comprises an amplification of chromosome position 1q21.

9. The method of claim 4, wherein the immunoconjugate is formulated for intravenous infusion.

10. The use according to any one of claims 4 to 9, wherein when the pharmaceutical composition is used, the immunoconjugate is administered to the human subject every 7 days, every 14 days, every 18 days, every 21 days, every 28 days or every month.

11. The use according to claim 10, wherein when the pharmaceutical composition is used, the immunoconjugate is administered to the human subject every 21 days.

12. The use according to any one of claims 4 to 9 and 11, wherein when the pharmaceutical composition is used, the immunoconjugate is administered at a dose of 1.2 to 3.0 mg / kg.

13. The use according to claim 12, wherein when the pharmaceutical composition is used, the immunoconjugate is administered at a dose of 1.8, 2.4, 2.7 or 3.0 mg / kg.

14. Use according to claim 12, wherein the weight of the human subject in kg is actual body weight.

15. The use according to claim 12, wherein the weight of the human subject in kg is an adjusted body weight.

16. The use according to claim 12, wherein: If the actual weight of the human subject is less than the subject's adjusted weight, the weight of the human subject in kg is the actual weight of the human subject; If the actual weight of the human subject is greater than or equal to the adjusted weight of the subject, and the adjusted weight of the human subject is less than 100 kg, the weight of the human subject in kg is the adjusted weight of the human subject; or If the adjusted body weight of the human subject is greater than or equal to 100 kg, the weight of the human subject in kg is 100 kg.

17. A pharmaceutical formulation for treating refractory multiple myeloma in a human subject in need thereof, comprising an immunoconjugate at a concentration of 10.0 ± 1.0 mg / mL, 20 mM histidine buffer at pH 6.0, 8.0% sucrose, and 0.01% polysorbate 80, wherein the immunoconjugate comprises: Recombinant antibodies, containing: a first heavy chain comprising SEQ ID NO: 9, a first light chain comprising SEQ ID NO: 10, a second heavy chain comprising SEQ ID NO: 9, and a second light chain comprising SEQ ID NO: 10; and one, two, three, or four pairs of adducts; wherein each of the one, two, three or four pairs of adducts comprises monomethyl auristatin E (MMAE) coupled to the recombinant antibody via a maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (mc-vc-PAB) linker; wherein each of the one, two, three or four pairs of adducts is coupled to a pair of cysteine ​​residues of the recombinant antibody, wherein the pair of cysteine ​​residues is selected from: C219 of the first heavy chain and C214 of the first light chain; C219 of the second heavy chain and C214 of the second light chain; C225 of the first heavy chain and C225 of the second heavy chain; and C228 of the first heavy chain and C228 of the second heavy chain.

18. Use of the pharmaceutical composition of claim 1 in the preparation of a medicament for treating metastatic castration-resistant prostate cancer (mCRPC) in a human subject in need thereof, wherein the immunoconjugate comprises: (i) an antibody that specifically binds to CD46, wherein the antibody comprises: a heavy chain (HC) variable region comprising three complementarity determining regions (CDRs): HC CDR1, HC CDR2, and HC CDR3, and A light chain comprising a light chain (LC) variable region, wherein the light chain (LC) variable region comprises three CDRs: LC CDR1, LC CDR2, and LC CDR3, wherein the HC CDR1 is SEQ ID NO: 1, the HC CDR2 is SEQ ID NO: 2, the HC CDR3 is SEQ ID NO: 3, the LC CDR1 is SEQ ID NO: 4, the LC CDR2 is SEQ ID NO: 5, and the LC CDR3 is SEQ ID NO: 6; It is coupled via a linker to (ii) monomethyl auristatin E (MMAE), wherein the linker comprises maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl; and wherein when the pharmaceutical composition is used, the pharmaceutical composition is administered at a dose determined according to the adjusted body weight of the human subject, wherein the dosage is from 1.2 mg of the immunoconjugate per kg of the human subject's adjusted body weight to 3.0 mg of the immunoconjugate per kg of the human subject's adjusted body weight Wherein the adjusted juvenile body weight (AJBW) is: AJBW = IBW + 0.4 × (actual weight - IBW); Where IBW is ideal body weight and is: IBW = Y + 2.3 kg × (actual height - 60 inches); where for a male human subject, Y is 50 kg; and For female human subjects, Y is 45.5 kg; wherein the metastatic castration-resistant prostate cancer comprises cells expressing CD46, and wherein the mCRPC is treated.

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