Methods of treating invasive and metastatic cancers

Abstract

The present application discloses methods for treating cancer comprising administering a polymeric immunoglobulin receptor (pIgR) binder conjugated to a payload. Also described are methods for treating metastases comprising administering a pIgR binder conjugated to a payload. The payload can be a therapeutic such as a cytotoxic agent, a chemotherapeutic agent, or an immune-stimulatory agent. Also described are methods of delivering therapeutic payloads.

Description

METHODS OF TREATING INVASIVE AND METASTATIC CANCERSCROSS-REFERENCE

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 597,774 filed November 10, 2023, which is hereby incorporated by reference in its entirety.SEQUENCE LISTING

[0002] The instant application contains a Sequence Listing which has been filed electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on November 6, 2024, is named 67237-701.601 SL. xml and is 11,217 bytes in size.BACKGROUND

[0003] Cancer is a leading cause of death worldwide. The ability to invade and metastasize is a key mechanism of cancer pathogenesis and results in increased cancer growth. Local invasion and distal metastasis are the strongest factors contributing to deaths caused by cancer. Thus, there is a need for new methods to treat locally invasive and metastatic cancer. A shared common feature between local invasion and metastasis is the formation of cancer nests having the microarchitecture of closed apical lumen, which this method seeks to leverage for treatment.SUMMARY

[0004] Provided herein is a method of treating a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering to the subject a conjugate, wherein the conjugate comprises a polymeric immunoglobulin receptor (plgR) binder and a therapeutic payload, whereby the size, growth or viability of the cancer is decreased or inhibited.

[0005] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration.

[0006] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0007] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0008] In some embodiments, the plgR binder is an antibody or an antibody-like molecule.

[0009] In some embodiments, the plgR binder is a VHH.

[0010] In some embodiments, the cancer is surgically unresectable prior to treatment.

[0011] In some embodiments, the cancer is surgically resectable subsequent to treatment.

[0012] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate.

[0013] Provided herein is a method of treating a metastasis or local invasion of a cancer in a subject in need thereof, comprising administering to the subject a conjugate; wherein the conjugate comprises a plgR binder and a therapeutic payload, whereby the conjugate prevents or delays an occurrence of a metastatic lesion.

[0014] In some embodiments, the conjugate is administered to the subject prior to surgical resection of the cancer.

[0015] In some embodiments, the conjugate is administered subsequent to surgical resection of the cancer.

[0016] In some embodiments, the plgR binder is an antibody or an antibody-like molecule.

[0017] In some embodiments, plgR binder is a VHH.

[0018] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0019] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0020] In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen microarchitecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

[0021] In some embodiments, the conjugate is configured to transcytose to an interior space of the closed apical lumen microarchitecture.

[0022] Provided herein is a method of treating a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering to the subject a conjugate, wherein the conjugate comprises a plgR agonist and a therapeutic payload, whereby the size, growth, or viability of the cancer is decreased or inhibited.

[0023] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration.

[0024] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule.

[0025] In some embodiments, the plgR agonist is a VHH.

[0026] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0027] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0028] In some embodiments, the cancer is surgically unresectable prior to treatment.

[0029] In some embodiments, the cancer is surgically resectable subsequent to treatment.

[0030] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate.

[0031] Provided herein is a method of treating a metastasis or local invasion of a cancer in a subject in need thereof, comprising administering to the subject a conjugate; wherein the conjugate comprises a plgR agonist and a therapeutic payload, whereby the conjugate prevents or delays an occurrence of a metastatic lesion.

[0032] In some embodiments, the conjugate is administered to the subject prior to surgical resection of the cancer.

[0033] In some embodiments, the conjugate is administered subsequent to surgical resection of the cancer.

[0034] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule.

[0035] In some embodiments, the plgR agonist is a VHH.

[0036] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0037] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0038] In some embodiments, the metastasis to be treated has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

[0039] In some embodiments, the conjugate is configured to transcytose to an interior space of the closed apical lumen microarchitecture.

[0040] Provided herein is a method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

[0041] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0042] In some embodiments, therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0043] In some embodiments, the plgR binder is an antibody or an antibody-like molecule.

[0044] In some embodiments, the plgR binder is a VHH.

[0045] In some embodiments, the cancer is surgically unresectable prior to delivery.

[0046] In some embodiments, the cancer is surgically resectable subsequent to delivery.

[0047] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to delivery.

[0048] Provided herein is a method of delivering a therapeutic payload into a lumen of a metastasis or a local invasion of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

[0049] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0050] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0051] In some embodiments, the plgR binder is an antibody or an antibody-like molecule.

[0052] In some embodiments, the plgR binder is a VHH.

[0053] In some embodiments, the metastasis or the local invasion has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

[0054] Provided herein is a method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

[0055] In some embodiments, the therapeutic agent is a protein, or a polynucleic acid, or a small molecule.

[0056] In some embodiments, the therapeutic agent is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0057] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule.

[0058] In some embodiments, the plgR agonist is a VHH.

[0059] In some embodiments, the cancer is surgically unresectable prior to delivery.

[0060] In some embodiments, the cancer is surgically resectable subsequent to delivery.

[0061] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to delivery.

[0062] Provided herein is a method of delivering a therapeutic payload into a lumen of a metastasis of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

[0063] In some embodiments, the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

[0064] In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

[0065] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule.

[0066] In some embodiments, the plgR agonist is a VHH.

[0067] In some embodiments, the metastasis has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

[0068] In some embodiments, the cancer is a colorectal, pancreatic, gastric, endometrial, or nonsmall cell lung cancer, or a combination thereof.

[0069] In some embodiments, the cancer is an adenocarcinoma.

[0070] In some embodiments, the cancer is locally invasive.

[0071] In some embodiments, the cancer is metastatic.

[0072] In some embodiments, the cancer to be treated expresses plgR.

[0073] In some embodiments, the cancer has a closed apical lumen architecture with preserved basal and apical polarity.

[0074] In some embodiments, wherein the metastasis has a closed apical lumen architecture with preserved basal and apical polarity.

[0075] In some embodiments, the antibody or the antibody-like molecule comprises a heavy chain, wherein the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4 or SEQ ID NO: 7.

[0076] In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 2 (HCDR2) comprising a sequence set forth in SEQ ID NO: 3 or SEQ ID NO: 6.

[0077] In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 1 (HCDR1) comprising a sequence set forth in SEQ ID NO: 2 or SEQ ID NO: 5.

[0078] In some embodiments, the antibody or antibody-like molecule comprises a light chain, wherein the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11.

[0079] In some embodiments, the light chain comprises a light chain complementarity determining region 2 (LCDR2) comprising a sequence set forth in SEQ ID NO: 10.

[0080] In some embodiments, the light chain comprises a light chain complementarity determining region 1 (LCDR1) comprising a sequence set forth in SEQ ID NO: 9.

[0081] In some embodiments, the heavy chain comprises a sequence with at least 80% sequence identity to the sequence set forth in SEQ ID NO: 1.

[0082] In some embodiments, the light chain comprises a sequence with at least 80% sequence identity to the sequence set forth in SEQ ID NO: 8.INCORPORATION BY REFERENCE

[0083] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and / or take precedence over any such contradictory material.BRIEF DESCRIPTION OF THE DRAWINGS

[0084] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also “Figure” and “FIG.” herein), of which:

[0085] FIGs. 1A-1B depict RNA sequencing data quantifying the gene expression of plgR. Expression was quantified using publicly available data obtained either from The Cancer Genome Atlas (FIG. 1A) or the Cancer Cell Line Encyclopedia (FIG. IB).

[0086] FIG. 2A depicts immunohistochemistry (IHC) results comparing protein expression of plgR in primary cancers and metastases in patient-matched samples.

[0087] FIG. 2B depicts tissue sample of metastatic (left) and invasive (right) colorectal adenocarcinoma stained with hematoxylin and eosin (H&E) to identify closed apical lumens, indicated by arrows.

[0088] FIG. 2C depicts IHC results staining for villin-like protein in a tissue sample of metastatic colorectal adenocarcinoma.

[0089] FIG. 2D is a quantification of the percentage of patients whose metastases were either positive for three criteria associated with the mechanism of action (expression of plgR protein, closed apical lumen architecture in metastases, and expression of villin-like protein in the lumen of metastases) or demonstrated less than three of criteria.

[0090] FIGs. 3A-3B show results of fluorescence microscopy (FIG. 3A) and IHC (FIG. 3B) experiments used to screen for plgR binding antibodies in Madin-Darby canine kidney (MDCK) cells expressing plgR.

[0091] FIG. 4A illustrates an experimental schema of a Transwell® assay used to measure accumulation of plgR agonists following transcytosis from the basal well across the Transwell® barrier to the apical well.

[0092] FIG. 4B is a quantification of the apical to basal ratio of luciferase activity using a plgR agonist fused to a NANOLUC® luciferase compared to a non-specific agonist control.

[0093] FIG. 5A depicts results from a bioluminescence interferometry assay demonstrating the binding of monoclonal and polyclonal antibodies to plgR immobilized on biosensors.

[0094] FIG. 5B illustrates a Transwell® setup used to measure antibody transcytosis.

[0095] FIG. 5C depicts results quantifying antibodies by ELISA and converted to units of ng / mL / 24 hours. Transcytosis of ToolAb and mlgGl was measured in MDCK cells with (+) and without (none) plgR over-expression via lentiviral transduction. Mouse IgG isotype (mlgG) control was also included for the MDCK cells with plgR over-expression.

[0096] FIG. 6A is a schematic illustrating how fluorescently labeled antibodies accumulate in the lumen of LSI 80 or MDCK spheroids via plgR.

[0097] FIG. 6B depicts flow cytometry analysis of LSI 80 cells stained with either anti-pIgR ToolAb (top) or mouse IgG isotype control (bottom), followed by secondary antibody staining.

[0098] FIG. 6C depicts quantification of the fluorescent signal ratio between the lumen and surrounding media for the LSI 80 spheroid. Fluorescent signals from the lumen of 25 spheroids, treated with either fluorescently-labeled ToolAb or IgG-isotype control added to LS180 spheroids' media were measured. The lumenal fluorescent signal was compared to the signal present in the surrounding media for each spheroid.

[0099] FIG. 6D depicts quantification of the fluorescent signal ratio between the lumen and surrounding media in LSI 80 spheroids. Fluorescent signals were measured from the lumen of 25 spheroids treated with fluorescently labeled ToolAb. The treatment was applied either to MDCK cells transduced with plgR-expressing lentivirus or to parental MDCK cells. The lumenal fluorescent signal was compared to each spheroid's corresponding signal in the surrounding media.DETAILED DESCRIPTIONPolymeric Immunoglobulin Receptor (plgR)

[0100] The polymeric immunoglobulin receptor (plgR) is a highly conserved transmembrane protein that is commonly expressed in mucosal epithelial cells, e.g., in the gastrointestinal tract where these cells form a barrier between the intestinal lumen and the basal layers like the lamina propria. The primary function of plgR is to traffic secreted polymeric immunoglobulin (pig) produced by antibody-secreting cells in lamina propria to the lumen, where they can mediate anti-microbial functions and regulate the microbiome. In order to accomplish trafficking, the secreted immunoglobulins (e.g., dimeric IgA or pentameric IgM) bind to plgR which triggers an endocytosis and transcytosis mechanism that begins to traffic the immunoglobulin / receptor complex through the epithelial cell. A proteolytic cleavage step then occurs which frees the pig along with a secretory component derived from the plgR, which are then released to the mucosal surface. In the context of cancer, analysis of The Cancer Genome Atlas demonstrated that many cancer types express plgR at the mRNA level, being most prevalent in colorectal, gastric, pancreatic, uterine, kidney, lung, and other cancers (FIG. 1A).

[0101] Provided herein, is a method of treating a cancer by administering a binder for plgR conjugated to a therapeutic payload. plgR binders can induce transcytosis of the therapeutic payload and release mechanisms which are induced by binding of native ligands (e.g., native pig). In some embodiments, the plgR binder is an antibody. In some embodiments, the plgRbinder is an antibody-like molecule. In some embodiments, the plgR agonist is a single-domain antibody (sdAb, also known as, for example, as a VHH).

[0102] Provided herein, is a method of treating a cancer by administering an agonist for plgR conjugated to a therapeutic payload. plgR agonists can induce transcytosis of the therapeutic payload and release mechanisms which are induced by binding of native ligands (e.g., native pig). In some embodiments, the plgR agonist is an antibody. In some embodiments, the plgR agonist is an antibody-like molecule. In some embodiments, the plgR agonist is a single-domain antibody (sdAb, also known as, for example, as a VHH).Binder Conjugates

[0103] In the described binder conjugates, the binder is conjugated to a therapeutic payload. The payload can be, for example, a cytotoxic molecule, a chemotherapeutic agent, an immune- stimulatory agent, etc., which is effective in killing cancer cells. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon-y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0104] In one instance, the conjugate includes an antibody conjugated to a cytotoxic molecule. In another instance, the conjugate includes an antibody fragment conjugated to a cytotoxic molecule. In another instance, the conjugate includes a single-domain antibody conjugated to a cytotoxic molecule. In another instance, the conjugate includes an antibody conjugated to a chemotherapeutic agent. In another instance, the conjugate includes an antibody fragment conjugated to a chemotherapeutic agent. In another instance, the conjugate includes a singledomain antibody conjugated to a chemotherapeutic agent. In another instance, the conjugate includes an antibody conjugated to an immune-stimulatory agent. In another instance, the conjugate includes an antibody fragment conjugated to an immune-stimulatory agent. In another instance, the conjugate includes a single-domain antibody conjugated to an immune-stimulatory agent.

[0105] Therapeutic payloads may be conjugated to plgR binders by conventional means known in the art. Conjugation methods may include stochastic or site-specific methods. Conjugation can occur through mechanisms including those involving valine-citrulline (vc) linkers, lysine resides, reduced cysteine resides, reactive cysteine residues, disulfide re-bridging, enzyme- assisted ligation, glycan remodeling, glycoconjugation, and / or click-chemistry approaches. Conjugation may be cleavable or non-cleavable in nature.Agonist Conjugates

[0106] In the described agonist conjugates, the agonist is conjugated to a therapeutic payload. The payload can be, for example, a cytotoxic molecule, a chemotherapeutic agent, an immune- stimulatory agent, etc., which is effective in killing cancer cells. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon-y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0107] In one instance, the conjugate includes an antibody conjugated to a cytotoxic molecule. In another instance, the conjugate includes an antibody fragment conjugated to a cytotoxic molecule. In another instance, the conjugate includes a single-domain antibody conjugated to a cytotoxic molecule. In another instance, the conjugate includes an antibody conjugated to a chemotherapeutic agent. In another instance, the conjugate includes an antibody fragment conjugated to a chemotherapeutic agent. In another instance, the conjugate includes a singledomain antibody conjugated to a chemotherapeutic agent. In another instance, the conjugate includes an antibody conjugated to an immune-stimulatory agent. In another instance, the conjugate includes an antibody fragment conjugated to an immune-stimulatory agent. In another instance, the conjugate includes a single-domain antibody conjugated to an immune-stimulatory agent.

[0108] Therapeutic payloads may be conjugated to plgR agonists by conventional means known in the art. Conjugation methods may include stochastic or site-specific methods. Conjugationcan occur through mechanisms including those involving valine-citrulline (vc) linkers, lysine resides, reduced cysteine resides, reactive cysteine residues, disulfide re-bridging, enzyme- assisted ligation, glycan remodeling, glycoconjugation, and / or click-chemistry approaches. Conjugation may be cleavable or non-cleavable in nature.Pharmaceutical compositions

[0109] Provided herein is a pharmaceutical composition comprising (a) a conjugate comprising a plgR agonist and a therapeutic payload, and (b) a pharmaceutically acceptable carrier. Also provided herein is a pharmaceutical composition comprising (a) a conjugate comprising a plgR binder and a therapeutic payload, and (b) a pharmaceutically acceptable carrier. The term “pharmaceutically acceptable” refers to approved or approvable by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia (U.S.P.) or other generally recognized pharmacopeia for use in animals, including humans. A “pharmaceutically acceptable carrier” refers to a carrier that can be administered to a subject, together with an active moiety, and which does not destroy the pharmacological activity thereof and is nontoxic when administered in doses sufficient to deliver a therapeutic amount of the moiety.Methods of treatment

[0110] Conjugates described herein can be utilized in the treatment of cancers. In one aspect, provided herein are methods of treating a cancer in a subject in need thereof, comprising administering to the subject an effective amount of the conjugate. In some embodiments, the cancer has a closed apical lumen microarchitecture. In some embodiments, the conjugate comprises a plgR binder and a therapeutic payload. In some embodiments, the size of the cancer is decreased or inhibited. In some embodiments, the growth of the cancer is decreased or inhibited. In some embodiments, the viability of the cancer is decreased or inhibited. In some embodiments, the cancer to be treated expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.[OHl] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxicmolecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon- y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0112] In some embodiments, the plgR binder is an antibody or an antibody-like molecule. In some embodiments, the plgR binder is a VHH. In some embodiments, the plgR binder comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR binder comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0113] In some embodiments, the cancer is surgically unresectable prior to treatment. In some embodiments, the cancer is surgically resectable subsequent to treatment. In some embodiments, the conjugate is administered to the subject prior to surgical resection of the cancer. In someembodiments, the conjugate is administered to the subject subsequent to surgical resection of the cancer.

[0114] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0115] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0116] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the cancer to be treated has a closed apical lumen architecture. In some embodiments, the cancer to be treated expresses a plgR protein or a plgR gene. In some embodiments, the cancer to be treated has preserved basal and apical polarity. In some embodiments, the cancer to be treated has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the cancer to be treated has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the cancer to be treated expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the cancer to be treated has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0117] Also provided herein is a method of treating a metastasis or a local invasion of a cancer in a subject in need thereof. In some embodiments, the method comprises administering to the subject a conjugate. In some embodiments, the conjugate comprises a plgR binder and a therapeutic payload. In some embodiments, the conjugate prevents an occurrence of a metastatic lesion. In some embodiments, the conjugate delays an occurrence of a metastatic lesion.

[0118] In some embodiments, the cancer to be treated expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0119] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the metastasis or the local invasion following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon-y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0120] In some embodiments, the plgR binder is an antibody or an antibody-like molecule. In some embodiments, the plgR binder is a VHH. In some embodiments, the plgR binder comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, theheavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR binder comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0121] In some embodiments, the cancer is surgically unresectable prior to treatment. In some embodiments, the cancer is surgically resectable subsequent to treatment. In some embodiments, the conjugate is administered to the subject prior to surgical resection of the cancer. In some embodiments, the conjugate is administered to the subject subsequent to surgical resection of the cancer.

[0122] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0123] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in theprimary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0124] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0125] Also provided herein is a method of treating a cancer having a closed apical lumen microarchitecture in a subject in need thereof. In some embodiments, the method comprises administering to the subject a conjugate. In some embodiments, the conjugate comprises a plgR agonist and a therapeutic payload. In some embodiments, the size of the cancer is decreased or inhibited. In some embodiments, the growth of the cancer is decreased or inhibited. In some embodiments, the viability of the cancer is decreased or inhibited. In some embodiments, the cancer to be treated expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0126] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule.In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon- y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0127] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule. In some embodiments, the plgR agonist is a VHH. In some embodiments, the plgR agonist comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR agonist comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0128] In some embodiments, the cancer is surgically unresectable prior to treatment. In some embodiments, the cancer is surgically resectable subsequent to treatment. In some embodiments,the conjugate is administered to the subject prior to surgical resection of the cancer. In some embodiments, the conjugate is administered to the subject subsequent to surgical resection of the cancer.

[0129] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0130] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0131] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the cancer to be treated has a closed apical lumen architecture. In some embodiments, the cancer to be treated expresses a plgR protein or a plgR gene. In some embodiments, the cancer to be treated has preserved basal and apical polarity. In some embodiments, the cancer to be treated has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the cancer to be treated has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the cancer to be treated expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the cancer to be treated has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0132] Also provided herein is a method of treating a metastasis or a local invasion of a cancer in a subject in need thereof. In some embodiments, the method comprises administering to the subject a conjugate. In some embodiments, the conjugate comprises a plgR agonist and a therapeutic payload. In some embodiments, the conjugate prevents an occurrence of a metastatic lesion. In some embodiments, the conjugate delays an occurrence of a metastatic lesion.

[0133] In some embodiments, the cancer to be treated expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0134] In some embodiments, the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon- y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0135] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule. In some embodiments, the plgR agonist is a VHH. In some embodiments, the plgR agonist comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In someembodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR agonist comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0136] In some embodiments, the cancer is surgically unresectable prior to treatment. In some embodiments, the cancer is surgically resectable subsequent to treatment. In some embodiments, the conjugate is administered to the subject prior to surgical resection of the cancer. In some embodiments, the conjugate is administered to the subject subsequent to surgical resection of the cancer.

[0137] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0138] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0139] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0140] Administration of an effective amount of the conjugate can result in partial or complete reduction of one or more side-effects of the therapeutic payload, compared to administration of the therapeutic payload in an unconjugated form or compared to a placebo. Partial reduction includes, but is not limited to at least 2%, 5%, 10%, 20%, 30%, 40%, 50%, or more reduction of the one or more side-effects of the therapeutic payload. Alternatively, or in addition, administration of an effective amount of the conjugate can result in partial or complete reduction in one or more symptoms of cancer, which include but are not limited to cancer growth, frequency of metastasis, number of metastases, the size of a solid tumor, and / or viability of cancer cells. Partial reduction includes, but is not limited to, at least about 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least11%, at least 12%, at least 13%, at least 14%, at least 15%, at least 20%, at least 25%, at least30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or more reduction of the one or more side effects of cancer. Partial reduction includes, but is not limited to, at least about 2-fold, at least 3-fold, at least 5-fold, at least 6-fold, at least 7-fold, at least 8- fold, at least 9-fold, at least 10-fold or more reduction of the one or more side effects of cancer. Partial reduction includes, but is not limited to, at least about 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least12%, at least 13%, at least 14%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, %, at least 95%, or more reduction of the one or more symptoms of cancer. Partial reduction includes, but is not limited to, at least about 2-fold, at least 3-fold, at least 5-fold, at least 6-fold, at least 7-fold, at least 8-fold, at least 9-fold, at least 10-fold or more reduction of the one or more symptoms of cancer. Any of such partial or complete reductions above can be measured by comparing subjects receiving an effective amount of the conjugate to (a) the subject prior to treatment with the conjugate or (b) subjects receiving a placebo or other control. Assessment of symptoms can be performed by means known in the art. These means include, but are not limited to, imaging tests, e.g., CT scan, magnetic resonance imaging (MRI), X-ray, endoscopies, histological analysis of cancer specimen (e.g., H&E or immunohistochemistry, etc.), flow cytometric analysis of cancer specimen, and / or blood tests to detect biomarkers of cancer.

[0141] In some instances, administration of an effective amount of the conjugate may result in an increase in the activity of the therapeutic payload or in the local concentration of the therapeutic payload in a microenvironment of the cancer and / or its metastases. An increase may include but is not limited to at least about 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or more increase in activity of the therapeutic payload. Increases in therapeutic payload activity can be measured, for example, by comparing a subject receiving an effective amount of the conjugate to a subject receiving an unconjugated therapeutic payload.

[0142] In some instances, administration of an effective amount of the conjugate can result in stasis of symptoms of cancer. In other instances, the quality of life of a subject is improved or life is prolonged compared to (a) the subject prior to treatment or (b) the subject receiving a placebo or other control.Screening of Cancers Eligible for Treatment

[0143] Eligibility of a subject for treatment with any of the described methods can be assessed. In some embodiments, the methods disclosed herein comprise obtaining a histological diagnosis of the cancer prior to treatment. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression,quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0144] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0145] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0146] A cancer suitable for treatment with a conjugate described herein may exhibit one or more of the above criteria.Methods of Delivery

[0147] Provided herein is a method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

[0148] In some embodiments, the plgR binder conjugated to the therapeutic payload is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment,the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon-y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0149] In some embodiments, the plgR binder is an antibody or an antibody-like molecule. In some embodiments, the plgR binder is a VHH. In some embodiments, the plgR binder comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR binder comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0150] In some embodiments, the cancer is surgically unresectable prior to delivery. In some embodiments, the cancer is surgically resectable subsequent to delivery. In some embodiments, the plgR binder conjugated to the therapeutic payload is administered to the subject prior to surgical resection of the cancer. In some embodiments, the plgR binder conjugated to the therapeutic payload is administered to the subject subsequent to surgical resection of the cancer.

[0151] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the plgR binder conjugated to thetherapeutic payload. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0152] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0153] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the cancer has a closed apical lumen architecture. In some embodiments, the cancer expresses a plgR protein or a plgR gene. In some embodiments, the cancer has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the cancer has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the cancer expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0154] Also provided herein is a method of delivering a therapeutic payload into a lumen of a metastasis or a local invasion of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

[0155] In some embodiments, the cancer expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments,the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0156] In some embodiments, the plgR binder conjugated to the therapeutic payload is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the metastasis or the local invasion following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon- y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0157] In some embodiments, the plgR binder is an antibody or an antibody-like molecule. In some embodiments, the plgR binder is a VHH. In some embodiments, the plgR binder comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR binder comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In someembodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0158] In some embodiments, the cancer is surgically unresectable prior to treatment. In some embodiments, the cancer is surgically resectable subsequent to treatment. In some embodiments, the plgR binder conjugated to the therapeutic payload is administered to the subject prior to surgical resection of the cancer. In some embodiments, the plgR binder conjugated to the therapeutic payload is administered to the subject subsequent to surgical resection of the cancer.

[0159] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the plgR binder conjugated to the therapeutic payload. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0160] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0161] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by thepractitioner. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the metastasis or the local invasion to be treated has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0162] Also provided herein is a method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

[0163] In some embodiments, the cancer expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0164] In some embodiments, the plgR agonist conjugated to the therapeutic payload is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. Inanother embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon-y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0165] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule. In some embodiments, the plgR agonist is a VHH. In some embodiments, the plgR agonist comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR agonist comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0166] In some embodiments, the cancer is surgically unresectable prior to delivery. In some embodiments, the cancer is surgically resectable subsequent to delivery. In some embodiments, the plgR agonist conjugated to the therapeutic payload is administered to the subject prior to surgical resection of the cancer. In some embodiments, the plgR agonist conjugated to the therapeutic payload is administered to the subject subsequent to surgical resection of the cancer.

[0167] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the plgR agonist conjugated to the therapeutic payload. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific forplgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0168] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0169] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the cancer has a closed apical lumen architecture. In some embodiments, the cancer expresses a plgR protein or a plgR gene. In some embodiments, the cancer has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the cancer has a closed apical lumen architecture and has preserved basal and apical polarity. In some embodiments, the cancer expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0170] Also provided herein is a method of delivering a therapeutic payload into a lumen of a metastasis or a local invasion of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

[0171] In some embodiments, the cancer expresses plgR. In some embodiments, the cancer is an adenocarcinoma. In some embodiments, the cancer is locally invasive. In some embodiments, the cancer is a colorectal cancer. In some embodiments, the cancer is a pancreatic cancer. In some embodiments, the cancer is a gastric cancer. In some embodiments, the cancer is an endometrial cancer. In some embodiments, the cancer is a non-small cell lung cancer.

[0172] In some embodiments, the plgR agonist conjugated to the therapeutic payload is configured to transcytose to the interior space of the closed apical lumen microarchitecture ofthe metastasis or the local invasion following administration. In some embodiments, the therapeutic payload is a protein. In some embodiments, the therapeutic payload is a polynucleic acid. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. In some embodiments, the therapeutic payload is a small molecule. In some embodiments, the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent. In one embodiment, the payload can be the cytotoxic molecule. Cytotoxic molecules include, but are not limited to, a ricin A chain, a mutant Pseudomonas exotoxin, a diphtheria toxoid, a streptonigrin, a boamycin, a saporin, a gelonin, a pokeweed antiviral protein, a radionuclide, a radiometal, or any cytotoxic agent that is capable of killing cancer cells. In another embodiment, the payload is the chemotherapeutic agent. Chemotherapeutic agents include, but are not limited to, paclitaxel, maytansinoid derivatives (e.g., DM1, DM2, and DM4), docetaxel, doxorubicin, danuribicin, mithramycin, chromomycin, monomethyl auristatin E (MMAE), cyclophosphamide, mitoxantrone, melphalan, lamellarin D, irinotecan, topotecan, camtothecin, or any chemotherapeutic agent that is able to slow and or cease the growth of a cancer. In another embodiment, the payload is the immune-stimulatory agent. Immune-stimulatory agents include, but are not limited to, IL-2, interferon-a, interferon- y, or any agent that is able to elicit or potentiate an anti-cancer immune response.

[0173] In some embodiments, the plgR agonist is an antibody or an antibody-like molecule. In some embodiments, the plgR agonist is a VHH. In some embodiments, the plgR agonist comprises a heavy chain. In some embodiments, the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4. In some embodiments, the heavy chain comprises a heavy complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 7. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 3. In some embodiments, the heavy chain comprises a HCDR2 comprising a sequence set forth in SEQ ID NO: 6. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 2. In some embodiments, the heavy chain comprises a HCDR1 comprising a sequence set forth in SEQ ID NO: 5. In some embodiments, the plgR agonist comprises a light chain. In some embodiments, the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11. In some embodiments, the light chain comprises a LCDR2 comprising a sequence set forth in SEQ ID NO: 10. In some embodiments, the light chain comprises a LCDR1 comprising a sequence set forth in SEQ ID NO: 9. In some embodiments, the heavy chain comprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 1. In some embodiments, the light chaincomprises a sequence with at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence set forth in SEQ ID NO: 8.

[0174] In some embodiments, the cancer is surgically unresectable prior to delivery. In some embodiments, the cancer is surgically resectable subsequent to delivery. In some embodiments, the plgR agonist conjugated to the therapeutic payload is administered to the subject prior to surgical resection of the cancer. In some embodiments, the plgR agonist conjugated to the therapeutic payload is administered to the subject subsequent to surgical resection of the cancer.

[0175] In some embodiments, the method further comprises obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the plgR agonist conjugated to the therapeutic payload. Histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer through biopsy or resection and determining the expression of plgR in the cancer and / or its metastases. Expression of plgR may be determined by methods known in the art. These methods include, but are not limited to, RNA sequencing for plgR expression, quantitative PCR using primers specific for plgR, western blotting using antibodies specific for plgR, immunohistochemistry using antibodies specific for plgR, FACS analysis, etc. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0176] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the microarchitecture of the cancer and / or its metastases. Assessment of microarchitecture may be performed by methods known in the art. These methods include, but are not limited to, staining a slide containing the cancer tissue with hematoxylin and eosin or with additional immunohistochemistry. Analysis of the stained slide may include identification of closed apical lumen microarchitecture of metastasis or in the primary tumor. Results can be compared to results from a healthy subject and / or determined by the practitioner.

[0177] Alternatively, or in addition, histological diagnosis includes, but is not limited to, obtaining a specimen of the cancer and assessing the preservation of basal and apical polarity. Assessment of basal and apical polarity may be performed by methods known in the art. These methods include, in the case of colorectal cancers, performing immunohistochemistry using antibodies specific for villin-like protein (VLL) to verify enrichment of VLL expression on the apical side. Results can be compared to results from a healthy subject and / or determined by the practitioner. In some embodiments, the cancer has a closed apical lumen architecture. In some embodiments, the cancer expresses a plgR protein or a plgR gene. In some embodiments, the cancer has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture and expresses a plgR protein or a plgR gene. In some embodiments, the cancer has a closed apical lumen architecture and has preserved basal and apical polarity. Insome embodiments, the cancer expresses a plgR protein or a plgR gene and has preserved basal and apical polarity. In some embodiments, the cancer has a closed apical lumen architecture, expresses a plgR protein or a plgR gene, and has preserved basal and apical polarity.

[0178] In some embodiments, the therapeutic payload is a protein, polynucleic acid, or a small molecule. A polynucleic acid can include but is not limited to DNA, RNA, mRNA, siRNA, or miRNA. Payloads can also comprise a cytotoxic molecule, a chemotherapeutic agent, or an immune stimulatory agent as described herein.Certain Definitions

[0179] All terms are intended to be understood as they would be understood by a person skilled in the art. Unless defined otherwise, 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 disclosure pertains.

[0180] The following definitions supplement those in the art and are directed to the current application and are not to be imputed to any related or unrelated case, e.g., to any commonly owned patent or application. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present disclosure, the preferred materials and methods are described herein. Accordingly, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0181] The terminology used herein is for the purpose of describing particular cases only and is not intended to be limiting. In this application, the use of the singular includes the plural unless specifically stated otherwise. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0182] In this application, the use of “or” means “and / or” unless stated otherwise. The terms “and / or” and “any combination thereof’ and their grammatical equivalents as used herein, can be used interchangeably. These terms can convey that any combination is specifically contemplated. Solely for illustrative purposes, the following phrases “A, B, and / or C” or “A, B, C, or any combination thereof’ can mean “A individually; B individually; C individually; A and B; B and C; A and C; and A, B, and C.” The term “or” can be used conjunctively or disjunctively, unless the context specifically refers to a disjunctive use.

[0183] The term “about” or “approximately” can mean within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, “about” can mean a range of up to 20%, up to 15%, up to 10%, up to 5%, or up to 1% of a given value. Alternatively, particularly with respect to biological systems orprocesses, the term can mean within an order of magnitude, within 5-fold, or within 2-fold, of a value. Where particular values are described in the application and claims, unless otherwise stated the term “about” meaning within an acceptable error range for the particular value should be assumed.

[0184] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method or composition of the present disclosure, and vice versa. Furthermore, compositions of the present disclosure can be used to achieve methods of the present disclosure.

[0185] Reference in the specification to “some embodiments,” “an embodiment,” “one embodiment” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the present disclosures. To facilitate an understanding of the present disclosure, a number of terms and phrases are defined below.

[0186] Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or sub-range from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, as well as all intervening decimal values between the aforementioned integers such as, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. With respect to sub-ranges, “nested sub-ranges” that extend from either end point of the range are specifically contemplated. For example, a nested sub-range of an exemplary range of 1 to 50 may comprise 1 to 10, 1 to 20, 1 to 30, and 1 to 40 in one direction, or 50 to 40, 50 to 30, 50 to 20, and 50 to 10 in the other direction.

[0187] The term “subject” refers to an animal which is the object of treatment, observation, or experiment. By way of example only, a subject includes, but is not limited to, a mammal, including, but not limited to, a human or a non-human mammal, such as a non-human primate, bovine, equine, canine, ovine, or feline.

[0188] A plgR binder as defined herein is said to be “specific for” or “selectively binds to” plgR with an affinity that is at least 5 times, at least 10 times, at least 25 times, least 50 times, least 100 times, etc., better than the affinity with which a non-specific binder binds to plgR. Binders may comprise antibodies or fragments of antibodies.

[0189] A plgR agonist as defined herein is said to be “specific for” or “selectively binds to” plgR and induces transcytosis of the agonist in a basal to apical direction.

[0190] A “conjugate” as defined herein is said to be a product of a covalent linking reaction joining an agonist for plgR and a therapeutic payload, or a binder for plgR and a therapeutic payload. The term “antibody” refers to a class of proteins that are generally known as immunoglobulins, including, but not limited to IgGl, IgG2, IgG3, and IgG4), IgA (including IgAl and IgA2), IgD, IgE, IgM, and IgY. The term “antibody” includes, but is not limited to, full length antibodies and antigen-binding fragments such as, for example, single-domain antibodies (sdAb), single chain fragment variable (scFv), fragment antigen-binding region (Fab), or VHH. An “antibody” can be non-naturally occurring.

[0191] The term “microarchitecture” or “architecture” as used herein are used interchangeably and are said to be the structure and arrangement of a tissue which includes but is not limited to a cancer and its metastases. A “closed apical lumen” refers to a tissue structure that includes a lumen or opening completely enclosed by cells with the apical face of said cells being exposed to the lumen or opening.

[0192] “Polarity” or “apical and basal polarity” as used herein refers to the property of a cell or tissue to have different characteristics at the apical or lumen-facing end compared to the basal or basement membrane-facing end. Different characteristics include but are not limited to types of proteins expressed, quantities of proteins expressed, and structural differences such presence of cilial structures.

[0193] The term “metastasis” as used herein are said to refer to the development of secondary cancers apart from the primary cancer. This includes but is not limited to secondary cancers that may be in the process of forming from the primary cancer, secondary cancers near the primary cancer, and secondary cancers that have developed further and may be in a disparate region of the same tissue as the primary cancer or in a different tissue or organ entirely. “Micrometastasis” refers to a small metastasis, e.g., having a size less than about 5mm. The term “locally invasive” refers to a secondary cancer that has arisen near the primary cancer. This includes but is not limited to a secondary cancer within the same tissue as the primary cancer. This includes but is not limited to a secondary cancer within a different tissue near to the primary cancer.EXAMPLESExample 1: plgR Expression in Adenocarcinoma.

[0194] plgR expression was assessed first by its RNA expression. RNA Transcript per million (TPM) of plgR was obtained from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) public databases. TPM for plgR was plotted for the different cancers among human cancers as shown in FIG. 1A and cancer cell lines, shown in FIG. IB. Cancershigh in plgR expression included colorectal, gastric, pancreatic, endometrial, kidney, liver, prostate, esophageal, and lung cancers.

[0195] To further investigate plgR expression in primary versus metastatic cancers, immunohistochemistry (IHC) staining was performed on 28 patient-matched primary and metastatic samples in colorectal cancer. Briefly, 28 patient-matched primary and metastatic colorectal cancer (CRC) sample pairs arrayed on tumor microarray (TMA) were purchased from TissueArray. Staining was automated on a Leica Bond Rx autostainer. These samples were stained with anti-pIgR antibody (Sigma-Aldrich, HPA012012) at the titer of 1 :200 for 30 minutes, washed with Leica Bond Rx wash buffer, followed by secondary staining with antirabbit HRP secondary antibody and DAB immunohistochemical staining. The resulting images were captured and digitized on a Pramana SpectralHT scanner and analyzed by QuPath 0.4.3. As shown in FIG. 2A, 24 out of 28 metastatic cancer samples showed maintenance of more than 50% IHC signal of their respective primary cancers.Example 2: Assessment of Tumor Microarchitecture

[0196] Histology metastasis samples from 33 colorectal cancer patients were assessed for closed apical lumen microarchitecture. Eighteen out of 33 samples (58%) showed the presence of the closed apical lumen on the hematoxylin and eosin (H&E) slides. An example of the closed lumen is shown in FIG. 2B, with the metastasis on the left and the original invasive primary cancer on the right.

[0197] The basal and apical polarity of the tumor microarchitecture (TMA) was assessed with the apical side contacting the closed luminal space using anti-VILL IHC staining, automated on a Leica Bond Rx autostainer. Briefly, the patient-matched metastasis and primary cancer tumor microarray was stained with anti-VILL (villin-like protein) antibody (Proteintech, 15130-1-AP) at a titer of 1 : 1000 for 30 minutes, washed with Leica Bond wash buffer, incubated with antiRabbit HRP-conjugated secondary antibody, and washed Leica bond wash buffer. The resulting images were captured and digitized on a Pramana SpectralHT scanner and analyzed by QuPath 0.4.3. IHC staining showed that 62% of metastatic lesions have basal-to-apical polarity in the microarchitecture. Exemplary staining of a sample with the basal-to-apical microarchitecture is shown in FIG. 2C. These analyses indicate that a significant number of metastatic adenocarcinomas possess three (3) features associated with the mechanism of action: 1) expression of target 2) maintenance of the necessary microarchitecture and 3) Possession of the correct polarity for transporting and accumulating a plgR agonist in the apical lumen of the tumor.Example 3: Screening of plgR Agonists

[0198] plgR binding antibodies and VHH molecules were assessed for plgR-binding and transcytosis-agonizing activity.

[0199] To show the binding of the antibody to human plgR (hpIgR), the antigen-binding domain of the antibody was placed downstream (3') to the SP6 promoter. The antibody fragment protein was produced by in vitro transcription and translation (IVTT) with the Promega High Yield Wheat Germ kit (Cat# L3260), coupled to Fluorotect fluorescence labeling (Promega Cat# L5001). The labeled antibody moiety demonstrated staining on the hpIgR transfected MDCK II cells but not on the un-transfected control as shown in FIG. 3A. As shown in FIG. 3B, immunohistochemistry using HRP-conjugated secondary antibody against the primary antibody fragment showed binding on the MDCK II cells transfected with hpIgR but not on the untransfected control.Example 4: Accumulation of a plgR Agonist-Payload Conjugates

[0200] A Transwell® assay was used to demonstrate the ability of a reporter plgR conjugate comprising a NANOLUC® luciferase to accumulate against a concentration gradient. A cartoon depicting the Transwell® setup is shown in FIG. 4A. MDCKII cells transfected and selected for expression of a CMV-hpIgR construct were plated at 100,000 cells on the apical (top) chamber of 0.3 pm 12-well Transwell® plate. The apical and basal chamber each contains 300 pL and 1000 pL of culture media, respectively. Non-transfected MDCKII cells were plated as a control. In conditions of 37° C and 5% CO2, cells were grown to confluency, fed one additional time, and allowed to fully differentiate for 48 hours.

[0201] The anti-pIgR antibody nanoluciferase fusion protein and control antibody nanoluciferase fusion protein were made by in vitro transcription and translation (Promega High-Yield Wheat Germ Expression System (Promega Cat# L5001 )) using constructs driven by the SP6 promoter with the antibody fused in the C-terminus with NANOLUC® luciferase to facilitate bioluminescence readout. An equal concentration - 1 pL of produced protein per mL of culture media, was administered on both the apical and basal (bottom) chamber media (300 pL and 1000 pL in volume in the apical and basal chambers, respectively). Media from the apical and basal chambers were collected at 0 and 24 hours for NANOLUC® luciferase activity assessment using the NANO-GLO® reagent (Cat # N1110) and the GLOWMAX® plate reader. As shown in FIG. 4B, higher NANOLUC® luciferase activity was measured on the apical side at the 24-hour time point for the anti-pIgR agonist- NANOLUC® luciferase fusion but not the non-specific control agonist fusion. These results demonstrate the ability of the fusion protein to provide a plgR-driven accumulation against a concentration gradient.Example 5: Identification of a plgR-binding and agonistic mouse IgG antibody called ToolAb

[0202] Three mouse monoclonal antibodies against plgR and one sheep polyclonal antibody were evaluated for binding to human plgR (hpIgR) using bioluminescence interference (BLI). All four antibodies demonstrated binding with distinct profiles as shown in FIG. 5A. One mouse monoclonal IgG, designated "ToolAb," demonstrated transcytosis activity in the Transwell® assay. Transwell® assays were performed using MDCK cells expressing hpIgR as shown in FIG. 5B. Antibodies were added to the bottom basal chamber, collected in both the apical and basal chamber after 24 hours, and quantified by ELISA. One antibody, the ToolAb, exhibited target-specific transcytosis, whereas mouse IgGl isotype control (mlgGl) did not. Specifically, ToolAb transcytosis required hpIgR expression on MDCK cells as shown in FIG. 5C.

[0203] Mass spectrometry sequencing of the heavy and light chain of ToolAb was performed, the results of which are summarized in Table 1.Table 1. Sequence of ToolAb AntibodyExample 6: Accumulation of fluorescent payload conjugated to ToolAb

[0204] Spheroids, featuring enclosed lumens, were used as an in vitro model for invasive and metastatic cancer. ToolAb was labeled with CF594 fluorescent dye and added to media surrounding LSI 80 or MDCK spheroids to assess antibody accumulation, as shown in FIG. 6A.

[0205] Flow cytometry confirmed endogenous plgR expression on LSI 80 cells and ToolAb binding as shown in FIG. 6B.

[0206] Fluorescent signal accumulated in the spheroid lumen after 24 hours as shown in FIG.6C, but not with fluorescently labeled mlgG control. Similar results were obtained using MDCK cells transduced with plgR-expressing lentivirus but not parental cells, as shown in FIG. 6D.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method of treating a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering to the subject a conjugate, wherein the conjugate comprises a polymeric immunoglobulin receptor (plgR) binder and a therapeutic payload, whereby the size, growth or viability of the cancer is decreased or inhibited.

2. The method of claim 1, wherein the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration.

3. The method of claim 1 or 2, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

4. The method of any one of claims 1-3, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

5. The method of any one of claims 1-4, wherein the plgR binder is an antibody or an antibody-like molecule.

6. The method of any one of claims 1-5, wherein the plgR binder is a VHH.

7. The method of any one of claims 1-6, wherein the cancer is surgically unresectable prior to treatment.

8. The method of claim 7, wherein the cancer is surgically resectable subsequent to treatment.

9. The method of any one of claims 1-8, further comprising obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate.

10. A method of treating a metastasis or a local invasion of a cancer in a subject in need thereof, comprising administering to the subject a conjugate; wherein the conjugate comprises a plgR binder and a therapeutic payload, whereby the conjugate prevents or delays an occurrence of a metastatic lesion.

11. The method of claim 10, wherein the conjugate is administered to the subject prior to surgical resection of the cancer.

12. The method of claim 10, wherein the conjugate is administered subsequent to surgical resection of the cancer.

13. The method of any one of claims 10-12, wherein the plgR binder is an antibody or an antibody-like molecule.

14. The method of any one of claims 10-13, wherein the plgR binder is a VHH.

15. The method of any one of claims 10-14, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

16. The method of any one of claims 10-14, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

17. The method of any one of claims 10-16, wherein the metastasis or the local invasion to be treated has a closed apical lumen microarchitecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

18. The method of claim 17, wherein the conjugate is configured to transcytose to an interior space of the closed apical lumen microarchitecture.

19. A method of treating a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering to the subject a conjugate, wherein the conjugate comprises a plgR agonist and a therapeutic payload, whereby the size, growth, or viability of the cancer is decreased or inhibited.

20. The method of claim 19, wherein the conjugate is configured to transcytose to the interior space of the closed apical lumen microarchitecture of the cancer following administration.

21. The method of claims 19 or 20, wherein the plgR agonist is an antibody or an antibodylike molecule.

22. The method of any one of claims 19-21, wherein the plgR agonist is a VHH.

23. The method of any one of claims 19-22, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

24. The method of any one of claims 19-22, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

25. The method of any one of claims 19-24, wherein the cancer is surgically unresectable prior to treatment.

26. The method of claim 25, wherein the cancer is surgically resectable subsequent to treatment.

27. The method of any one of claims 19-26, further comprising obtaining a histologic diagnosis of the microarchitecture of the cancer prior to administering the conjugate.

28. A method of treating a metastasis or a local invasion of a cancer in a subject in need thereof, comprising administering to the subject a conjugate; wherein the conjugate comprises a plgR agonist and a therapeutic payload, whereby the conjugate prevents or delays an occurrence of a metastatic lesion.

29. The method of claim 28, wherein the conjugate is administered to the subject prior to surgical resection of the cancer.

30. The method of claim 28, wherein the conjugate is administered subsequent to surgical resection of the cancer.

31. The method of any one of claims 28-30, wherein the plgR agonist is an antibody or an antibody-like molecule.

32. The method of any one of claims 28-31, wherein the plgR agonist is a VHH.

33. The method of any one of claims 28-32, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

34. The method of any one of claims 28-32, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

35. The method of any one of claims 28-34, wherein the metastasis or the local invasion to be treated has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

36. The method of any one of claims 35, wherein the conjugate is configured to transcytose to an interior space of the closed apical lumen microarchitecture.

37. A method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

38. The method of claim 37, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

39. The method of claim 37, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

40. The method of any one of claims 37-39, wherein the plgR binder is an antibody or an antibody-like molecule.

41. The method of any one of claims 37-40, wherein the plgR binder is a VHH.

42. The method of any one of claims 37-41, wherein the cancer is surgically unresectable prior to delivery.

43. The method of claim 42, wherein the cancer is surgically resectable subsequent to delivery.

44. The method of any one of claims 37-43, further comprising obtaining a histologic diagnosis of the microarchitecture of the cancer prior to delivery.

45. A method of delivering a therapeutic payload into a lumen of a metastasis or a local invasion of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR binder conjugated to the therapeutic payload.

46. The method of claim 45, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

47. The method of claim 45, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

48. The method of any one of claims 45-47, wherein the plgR binder is an antibody or an antibody-like molecule.

49. The method of any one of claims 45-48, wherein the plgR binder is a VHH.

50. The method of any one of claims 45-49, wherein the metastasis or the local invasion has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

51. A method of delivering a therapeutic payload into a lumen of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

52. The method of claim 51, wherein the therapeutic agent is a protein, or a polynucleic acid, or a small molecule.

53. The method of claim 51 or 52, wherein the therapeutic agent is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

54. The method of any one of claims 51-53, wherein the plgR agonist is an antibody or an antibody-like molecule.

55. The method of any one of claims 51-54, wherein the plgR agonist is a VHH.

56. The method of any one of claims 51-55, wherein the cancer is surgically unresectable prior to delivery.

57. The method of claim 56, wherein the cancer is surgically resectable subsequent to delivery.

58. The method of any one of claims 51-57, further comprising obtaining a histologic diagnosis of the microarchitecture of the cancer prior to delivery.

59. A method of delivering a therapeutic payload into a lumen of a metastasis or a local invasion of a cancer having a closed apical lumen microarchitecture in a subject in need thereof, comprising administering a plgR agonist conjugated to the therapeutic payload.

60. The method of claim 59, wherein the therapeutic payload is a protein, or a polynucleic acid, or a small molecule.

61. The method of claim 59, wherein the therapeutic payload is a cytotoxic molecule, a chemotherapeutic agent, or an immune-stimulatory agent.

62. The method of any one of claims 59-61, wherein the plgR agonist is an antibody or an antibody-like molecule.

63. The method of any one of claims 59-62, wherein the plgR agonist is a VHH.

64. The method of any one of claims 59-63, wherein the metastasis has a closed apical lumen architecture, expresses plgR, has preserved basal and apical polarity, or a combination thereof.

65. The method of any one of claims 1-64, wherein the cancer is a colorectal, pancreatic, gastric, endometrial, or non-small cell lung cancer, or a combination thereof.

66. The method of any one of claims 1-65, wherein the cancer is an adenocarcinoma.

67. The method of any one of claims 1-66, wherein the cancer to be treated expresses plgR.

68. The method of any one of claims 1-67, wherein the cancer has a closed apical lumen architecture with preserved basal and apical polarity.

69. The method of any one of claims 10-18, 28-36, 45-50, or 59-68, wherein the metastasis or the local invasion has a closed apical lumen architecture with preserved basal and apical polarity.

70. The method of any one of claims 5-9, 13-18, 21-27, 31-36, 40-44, 48-50, 54-58, or 62- 69, wherein the antibody or the antibody-like molecule comprises a heavy chain, wherein the heavy chain comprises a heavy chain complementarity determining region 3 (HCDR3) comprising a sequence set forth in SEQ ID NO: 4 or SEQ ID NO: 7.

71. The method of claim 70, wherein the heavy chain comprises a heavy chain complementarity determining region 2 (HCDR2)comprising a sequence set forth in SEQ ID NO: 3 or SEQ ID NO: 6.

72. The method of claim 70 or 71, wherein the heavy chain comprises a heavy chain complementarity determining region 1 (HCDR1) comprising a sequence set forth in SEQ ID NO: 2 or SEQ ID NO: 5.

73. The method of any one of claims 70-72, wherein the antibody or antibody like molecule comprises a light chain, wherein the light chain comprises a light chain complementarity determining region 3 (LCDR3) comprising a sequence set forth in SEQ ID NO: 11.

74. The method of claim 73, wherein the light chain comprises a light chain complementarity determining region 2 (LCDR2) comprising a sequence set forth in SEQ ID NO: 10.

75. The method of claim 73 or 74, wherein the light chain comprises a light chain complementarity determining region 1 (LCDR1) comprising a sequence set forth in SEQ ID NO: 9.

76. The method of any one of claims 70-75, wherein the heavy chain comprises a sequence with at least 80% sequence identity to the sequence set forth in SEQ ID NO: 1.

77. The method of any one of claims 73-76, wherein the light chain comprises a sequence with at least 80% sequence identity to the sequence set forth in SEQ ID NO: 8.

Images