WO2025160502A1

WO2025160502A1 - Peptide receptor radionuclide therapy

Info

Publication number: WO2025160502A1
Application number: PCT/US2025/013083
Authority: WO
Inventors: Julie L. SUTCLIFFE; Tanushree GANGULY-MARION
Original assignee: University of California Berkeley; University of California San Diego UCSD
Current assignee: University of California Berkeley; University of California San Diego UCSD
Priority date: 2024-01-26
Filing date: 2025-01-25
Publication date: 2025-07-31
Anticipated expiration: 2026-07-26

Abstract

The present disclosure provides methods and related compositions that incorporate a molecularly targeted approach via the integrin subtype α_vβ₆ using Peptide Receptor Radionuclide Therapy (PRRT) and a theranostic approach.

Description

UCDA-42815.601 PEPTIDE RECEPTOR RADIONUCLIDE THERAPY CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority to U.S. Provisional Application No. 63/625,717, filed January 26, 2024, which is incorporated herein by reference in its entirety. SEQUENCE LISTING The text of the computer readable sequence listing filed herewith, titled “UCDA_42815_601_SequenceListing.xml” created January 24, 2025, having a file size of 8,574 bytes, is hereby incorporated by reference in its entirety. BACKGROUND Cancers continue to be in need of new and more effective therapeutics. Particularly, some cancers and subsets within those cancer types are recalcitrant to current approaches. For example, the incidence of pancreatic ductal adenocarcinoma (PDAC) continues to increase with an estimated 47,000 people diagnosed in the United States in 2018. Unfortunately, PDAC remains the most lethal cancer with 98% of people ultimately succumbing to the disease. Despite exhaustive testing and some encouraging advances in first-and second-line treatment, only one chemotherapy (gemcitabine) has been found to have any benefit in this disease. However, the clinical response rate is quite low (around 30%), and even lower in advanced cases (see, e.g., Andriulli A., et al., Ann. Surg. Oncol. 2011;19:1644–1662; Hashimoto K., et al., Oncology.2009;77:217–223). The lack of clinical options for pancreatic cancer coupled with the dismal outcome demonstrate a clear unmet need for investigation into new therapies. BRIEF SUMMARY In one aspect, the present disclosure provides therapeutic conjugates of Formula I:

UCDA-42815.601 IV); wherein RN is a peptide; and wherein ABM is an albumin binding moiety. In some embodiments, X is ABM-5G such that the resulting therapeutic conjugate is encompassed within Formula II: (Formula II). UCDA-42815.601 In some embodiments, X is 5G such that the resulting therapeutic conjugate is encompassed within Formula (Formula III). Such chemical moiety for RN. In some embodiments, the RN is ⁶⁷Cu. In some embodiments, the RN is selected from the group consisting of ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²¹²Pb, ²²³Ra, and ²²⁵Ac. In other instances, the RN for the conjugate has imaging (e.g., diagnostic uses) and RN is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, and ¹²⁵I, RNIn some cases, the therapeutic conjugates can also be imaged after administration. The therapeutic conjugates are not limited to a specific chemical moiety for the 5G as a peptide. In some embodiments, the peptide is configured to bind an αvβ6 integrin. In some embodiments, the peptide is an RGD peptide configured to bind an α_vβ₆ integrin. In some embodiments, the peptide is a PEGylated peptide. In some embodiments, the PEGylated peptide has the following amino acid sequence: GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide. In some embodiments, the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG28 (PEG 1500), and/or (PEG28)2 (PEG 1500×2). In some embodiments, the first PEG moiety and the second PEG moiety are the same. In some embodiments, the first PEG moiety and the second PEG moiety each comprise PEG28 (PEG 1500). Such therapeutic conjugates are not limited to a specific chemical moiety for the albumin binding moiety (ABM). In some embodiments, the ABM is a 4-(4- iodophenyl)butyric acid or a K(D-Abu-iodophenylbutyryl) moiety. Such therapeutic conjugates are not limited a specific use or function. In some embodiments, the therapeutic conjugates of Formula I, II, III, or IV are useful for delivering radioactivity to a patient or subject. In some embodiments, the therapeutic conjugates of UCDA-42815.601 Formula I, II, III, or IV are useful for treating or preventing cancer in a patient or subject. In some embodiments, the therapeutic conjugates of Formula I, II, III, or IV are useful in treating an αvβ6 integrin-related cancer. In a related aspect, the present disclosure provides methods of treating an αvβ6 integrin-related cancer comprising administering one or more doses of the therapeutic conjugate of Formula I. II, III, or IV to a subject in need of treatment. In some embodiments, the one or more doses comprise administering one dose. In some embodiments, the one or more doses comprises two, or three additional dose(s) (e.g., 4, 5, 6, 10, 20, 50, 100) of the therapeutic conjugate to the subject. Such methods are not limited to a specific amount of the one or more doses of the therapeutic conjugate of Formula I, II, III, or IV. In those embodiments where multiple doses of the therapeutic conjugate are administered to the subject, each dose can contain the same or a different amount of radioactivity and/or the same or a different amount of the peptide. Such methods of treating an α_vβ₆ integrin-related cancer comprising administering a dose of the therapeutic conjugate of Formula I, II, III, or IV to a subject in need of treatment are not limited to specific dose or type of dose of the therapeutic conjugate. In some embodiments, the dose is a radioactive dose. In some embodiments, the dose for the therapeutic conjugate of Formula I, II, III, or IV contains between about 25 mCi and about 200 mCi radioactivity. In some embodiments, the amount of radioactivity in the dose is about 25 mCi, 50 mCi, 100 mCi, 150 mCi, or 200 mCi. Such methods are not limited to a particular type or kind of αvβ6 integrin-related cancer. In some embodiments, the αvβ6 integrin-related cancer is pancreatic cancer, breast cancer, colorectal cancer, lung cancer, ovarian cancer, cervical cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, stomach cancer, or endometrial cancer. In some embodiments, the α_vβ₆ integrin-related cancer is a locally advanced, unresectable or metastatic form of cancer (e.g., pancreatic cancer, breast cancer, colorectal cancer, lung cancer, ovarian cancer, cervical cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, stomach cancer, or endometrial cancer). In some embodiments, the pancreatic cancer is locally advanced or metastatic pancreatic cancer; locally advanced, unresectable or metastatic pancreatic adenocarcinoma; or pancreatic ductal adenocarcinoma (PDAC). In some embodiments, the α_vβ₆ integrin-related cancer comprises a primary lesion and a metastatic lesion. In certain embodiments, the αvβ6 integrin-related cancer comprises a lesion in an adrenal gland, bone, brain, liver, lung or any combination thereof. UCDA-42815.601 In some embodiments, the subject receives a standard of care treatment prior to the administering of the dose of the therapeutic conjugate. In some embodiments, the subject receives a standard of care treatment subsequent to the administering of the dose of the therapeutic conjugate. In some embodiments, the subject receives a standard of care treatment prior to and subsequent to the administering of the dose of the therapeutic conjugate. In some embodiments, the standard of care treatment comprises one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. In particular embodiments, the standard of care treatment comprises FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin), gemcitabine, abraxane, irinotecan, or a combination thereof. In some embodiments, the method further comprises scanning the body of the subject or a portion thereof after administering the therapeutic conjugate. In certain embodiments, the scanning comprises positron emission tomography (PET), computed tomography (CT) scanning, magnetic resonance imaging (MRI), or single photon emission computerized tomography (SPECT). In some embodiments, the method further comprises administering a diagnostic conjugate prior to the administration of the therapeutic conjugate, wherein the diagnostic conjugate comprises an integrin binding moiety, such as an RGD peptide and a second radionuclide, such as a different radionuclide suitable for imaging. In certain embodiments, the second radionuclide is ⁶⁸Ga. In certain embodiments, the diagnostic conjugate is administered in a dose that contains up to about 5 mCi (e.g., greater than about 0.01 mCi to about 5 mCi) radioactivity. In some embodiments, the therapeutic conjugate is administered within 5 weeks after the administration of the diagnostic conjugate. In some embodiments, the method further comprises administering a solution of amino acids to the subject. In certain embodiments, the solution is administered prior to and concurrent with the administration of the therapeutic conjugate. In some embodiments, the therapeutic conjugate is administered to the subject by infusion. In some embodiments, the diagnostic conjugate is administered to the subject by injection. In some embodiments, the diagnostic conjugate is administered by bolus, slow bolus or slow infusion. In some embodiments, the therapeutic conjugate is administered by bolus, slow bolus or slow infusion. In some embodiments, the diagnostic conjugate is administered by bolus and the therapeutic conjugate is administered by slow bolus or slow infusion. In some embodiments, the therapeutic conjugate is infused over a period of minutes UCDA-42815.601 or hours, such as about 1 minute, about 2 minutes, about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 55 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, or about 8 hours. In particular embodiments, the therapeutic conjugate is infused over a period of about 30 minutes. In some embodiments, the diagnostic conjugate is infused over a period of minutes, such as about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, or less. In particular embodiments, the diagnostic conjugate is infused over a period of about 5 minutes or less. In some embodiments, the treatment results in stable disease, partial remission or complete remission. In some embodiments, the treatment results in a reduction in metastases of the cancer in the subject. In some embodiments, the treatment results in a reduction in volume, size or growth of a tumor in the subject. In some embodiments, the treatment results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent. In some embodiments, the amount of the therapeutic conjugate that is present in kidney tissue at about 24 hours, about 48 hours or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in kidney tissue at one hour after administration of the conjugate. In some embodiments, the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in kidney tissue at about 24 hours, about 48 hours or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in kidney tissue at 1 hour after administration of the conjugate. In another aspect, the present disclosure provides a pharmaceutical composition comprising a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1). In some embodiments, a PEG moiety is covalently attached at the N-terminus, the C-terminus or both the N- and C-termini of the peptide. In some embodiments, the PEG moiety is independently selected from the group consisting of PEG11, PEG12 (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG₂₈)₂ (PEG 1500×2). In other embodiments, a first PEG moiety is covalently attached to the N-terminus of the peptide and a second PEG moiety is covalently attached to the C-terminus of the peptide, and the first PEG moiety and the second UCDA-42815.601 PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG₂₈)₂ (PEG 1500×2). In some instances, the first PEG moiety and the second PEG moiety are the same. In particular instances, the first PEG moiety and the second PEG moiety each comprises PEG₂₈ (PEG 1500). In some embodiments, the PEG moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some embodiments, the peptide is covalently attached to an albumin binding moiety (ABM). In particular embodiments, the ABM comprises 4-(4-iodophenyl)butyric acid. In some embodiments, the ABM includes a linker, such as a peptide linker that is covalently attached to the peptide, the first PEG moiety, or the second PEG moiety. In certain embodiments, the ABM comprises a K(D-Abu-iodophenylbutyryl) moiety. In some embodiments, the peptide is covalently attached to a chelating moiety. In particular embodiments, the chelating moiety is NOTA (

UCDA-42815.601 ) or DOTA ( ). In certain instances, a radionuclide (RN) is complexed with the chelating moiety. In some embodiments, a radionuclide is covalently attached directly or indirectly to the peptide. In some instances, the RN is selected from the group consisting of ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²¹²Pb ²²³Ra, and ²²⁵Ac. In other instances, the RN is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, ²⁰³Pb. In other instances, the RN is ¹⁷⁷Lu or ⁶⁸Ga. In other instances, the RN is ⁶⁷Cu or ⁶⁴Cu. UCDA-42815.601 In a related aspect, the present disclosure provides a pharmaceutical composition comprising a conjugate of (Formula I) or Formula (Formula IV); BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 shows cell-binding and internalization at 1 h, 37 °C in integrin α_vβ₆(+) Capan-1 cells (n = 3/compound); bars: SD. Peptides 1 = DOTA-ABM-5G (

UCDA-42815.601 ( images of mice bearing Capan-1 tumors (yellow arrow) obtained after injection of imaging peptides ⁶⁴Cu-1 and ⁶⁴Cu-2 . K- Kidneys, L- Liver. PET scale in color. FIGS.3A-3B show biodistribution of imaging peptides ⁶⁴Cu-1 (A) and ⁶⁴Cu-2 (B) presented as percentage of injected dose per gram (%ID/g) of tissue in mice bearing α_vβ₆ (+) Capan-1 tumors (n = 3/group/time point). FIGS.4A-4C show (A) Capan-1 tumor uptake. (B) Kidney uptake and (C) Capan- 1-to-Kidney ratios for ⁶⁴Cu-1, ⁶⁴Cu-2, compared to current radiotherapeutic ¹⁷⁷Lu-DOTA- ABM-5G (¹⁷⁷Lu-1). Peptides 1 = DOTA-ABM-5G; 2 = NOTA-ABM-5G. FIG.5 shows average tumor volume over days 0 to 42 for mice receiving a control, one dose of 37 MBq ⁶⁷Cu-1 at Day 0, or 4 doses each of 37 MBq ⁶⁷Cu-1 at Day 0, Day 7, Day 14 and Day 28. DETAILED DESCRIPTION UCDA-42815.601 I. Introduction Provided herein are methods and related compositions that incorporate a molecularly targeted approach via the integrin subtype αvβ6 using Peptide Receptor Radionuclide Therapy (PRRT) and a theranostic approach. The integrin subtype αvβ6 is an epithelial-specific cell surface receptor that is undetectable in healthy adult epithelium but is significantly up-regulated in a wide range of epithelial-derived cancers, including pancreatic ductal adenocarcinoma (PDAC). αvβ6 was initially identified in PDAC and almost all tumors demonstrate highly upregulated expression of αvβ6. PRRT is a therapy that employs a cell-targeting peptide combined with a radionuclide. When injected into the patient’s bloodstream, the radioactive peptide delivers a targeted high dose of radiation directly to the cancer cells. II. Definitions Unless specifically indicated otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. In addition, any method or material similar or equivalent to a method or material described herein can be used in the practice of the present disclosure. For purposes of the present disclosure, the following terms are defined. The terms “a,” “an,” or “the” as used herein not only include aspects with one member, but also include aspects with more than one member. For instance, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a conjugate” includes a plurality of such conjugates, and so forth. The term “about” is used herein to modify a numerical value and indicate a defined range around that value. If “X” is the value, “about X” generally indicates a value from 0.90X to 1.10X. Any reference to “about X” indicates at least the values X, 0.90X, 0.91X, 0.92X, 0.93X, 0.94X, 0.95X, 0.96X, 0.97X, 0.98X, 0.99X, 1.01X, 1.02X, 1.03X, 1.04X, 1.05X, 1.06X, 1.07X, 1.08X, 1.09X, and 1.10X. Thus, “about X” is intended to disclose, e.g., “0.98X.” When “about” is applied to the beginning of a numerical range, it applies to both ends of the range. When “about” is applied to the first value of a set of values, it applies to all values in that set. The term “peptide” refers to a compound made up of a single chain of D- or L- amino acids or a mixture of D- and L-amino acids joined by peptide bonds. Generally, UCDA-42815.601 peptides are about 2 to about 50 amino acids in length. As non-limiting examples, the peptides present in the conjugates described herein are between about 5 to about 45 amino acids in length, between about 8 to about 45 amino acids in length, between about 8 to about 25 amino acids in length, between about 8 to about 20 amino acids in length, between about 12 to about 45 amino acids in length, between about 12 to about 30 amino acids in length, or about 20 amino acids in length. The term "RGD peptide" refers to a polypeptide comprising an arginine-glycine- aspartic acid (Arg-Gly-Asp) tripeptide motif recognized by an integrin (e.g., α_vβ₆ integrin). Indeed, as used herein, “RGD peptide” refers to the binding/interaction of a peptide motif in a conjugate described herein which shows the capacity of specific interaction with α_vβ₆ integrin. In some embodiments, the RGD peptide interacts with and/or binds to αvβ6 integrin without cross-reacting with molecules of similar sequences or structures. In some instances, the RGD peptide specifically binds to αvβ6 integrin when it binds with a substantially lower dissociation constant (i.e., tighter binding) than a molecule of similar sequence or structure. For example, in certain instances, a specific binding occurs when the RGD peptide binds to αvβ6 integrin with an about 2, 3, 4, 5, 6, 8, 10, 15, 20, 25, 30, 40, 50, 100, or 1000-fold or greater affinity than a related molecule. The binding of the RGD peptide to α_vβ₆ integrin may occur via intermolecular forces such as ionic bonds, hydrogen bonds, hydrophobic interactions, dipole-dipole bonds, and/or Van der Waals forces. Cross-reactivity may be tested, for example, by assessing binding of the RGD peptide under conventional conditions to α_vβ₆ integrin as well as to a number of more or less (e.g., structurally and/or functionally) closely related molecules. These methods may include, without limitation, binding studies, blocking and competition studies with closely related molecules, FACS analysis, surface plasmon resonance (e.g., with BIAcore), analytical ultracentrifugation, isothermal titration calorimetry, fluorescence anisotropy, fluorescence spectroscopy, radiolabeled ligand binding assays, and combinations thereof. As used herein, the term “PEGylation” refers to the process of covalently coupling a polyethylene glycol (PEG) molecule to another molecule, e.g., an RGD peptide, which is then referred to as “PEGylated.” As a non-limiting example, an RGD peptide may be PEGylated at both the amino-terminus and the carboxyl terminus with monodisperse PEG molecules having a defined chain length to generate bi-terminal PEGylated peptide conjugates. Monodisperse PEG molecules typically comprise discrete molecular weights with an exactly defined number of repeating ethylene glycol units. PEG moieties suitable for use are commercially available from Polypure AS (Oslo, Norway), which supplies monodisperse UCDA-42815.601 PEG molecules and PEG derivatives thereof consisting of substantially one oligomer only (e.g., greater than about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% oligomer purity). In particular embodiments, the RGD peptide is PEGylated at both ends with a single type or mixtures of different types of monodisperse PEG moieties having a molecular weight of less than about 5,000 daltons (Da) (e.g., less than about 5,000, 4,000, or 3,000 Da), such as, e.g., PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG₂₈)₂ (PEG 1500×2). The term “radionuclide” is intended to include any nuclide that exhibits radioactivity. A “nuclide” refers to a type of atom specified by its atomic number, atomic mass, and energy state, such as carbon 14 (¹⁴C). “Radioactivity” refers to the radiation, including alpha particles, beta particles, nucleons, electrons, positrons, neutrinos, and gamma rays, emitted by a radioactive substance. Examples of radionuclides suitable for use in the conjugates described herein include, but are not limited to, tritium (³H), fluorine 18 (¹⁸F), phosphorus 32 (³²P), sulfur 35 (³⁵S), scandium 47 (⁴⁷Sc), cobalt 55 (⁵⁵Co), copper 60 (⁶⁰Cu), copper 61 (⁶¹Cu), copper 62 (⁶²Cu), copper 64 (⁶⁴Cu), gallium 66 (⁶⁶Ga), copper 67 (⁶⁷Cu), gallium 67 (⁶⁷Ga), gallium 68 (⁶⁸Ga), rubidium 82 (⁸²Rb), yttrium 86 (⁸⁶Y), yttrium 87 (⁸⁷Y), strontium 89 (⁸⁹Sr), strontium 90 (⁹⁰Sr), yttrium 90 (⁹⁰Y), rhodium 105 (¹⁰⁵Rh), silver 111 (¹¹¹Ag), indium 111 (¹¹¹In), iodine 124 (¹²⁴I), iodine 125 (¹²⁵I), iodine 131 (¹³¹I), tin 117m (^117mSn), technetium 99m (^99mTc), cesium 137 (¹³⁷Cs), promethium 149 (¹⁴⁹Pm), samarium 153 (¹⁵³Sm), terbium 149 (¹⁴⁹Tb), terbium 152 (¹⁵²Tb), terbium 155 (¹⁵⁵Tb), terbium 161 (¹⁶¹Tb), holmium 166 (¹⁶⁶Ho), lutetium 177 (¹⁷⁷Lu), rhenium 186 (¹⁸⁶Re), rhenium 188 (¹⁸⁸Re), thallium 201 (²⁰¹Tl), astatine 211 (²¹¹At), astatine 215 (²¹⁵At), astatine 217 (²¹⁷At), astatine 218 (²¹⁸At), bismuth 209 (²⁰⁹Bi), bismuth 211 (²¹¹Bi), bismuth 212 (²¹²Bi), bismuth 213 (²¹³Bi), lead 203 (²⁰³Pb), lead 212 (²¹²Pb), polonium 210 (²¹⁰Po), polonium 211 (²¹¹Po), polonium 212 (²¹²Po), polonium 214 (²¹⁴Po), polonium 215 (²¹⁵Po), polonium 216 (²¹⁶Po), polonium 218 (²¹⁸Po), radon 218 (²¹⁸Rn), radon 219 (²¹⁹Rn), radon 220 (²²⁰Rn), radon 222 (²²²Rn), radon 226 (²²⁶Rn), francium 221 (²²¹Fr), radium 223 (²²³Ra), radium 224 (²²⁴Ra), radium 226 (²²⁶Ra), actinium 225 (²²⁵Ac), actinium 227 (²²⁷Ac), thorium 227 (²²⁷Th), thorium 228 (²²⁸Th), thorium 229 (²²⁹Th), thorium 230 (²³⁰Th), thorium 232 (²³²Th), protactinium 231 (²³¹Pa), uranium 233 (²³³U), uranium 234 (²³⁴U), uranium 235 (²³⁵U), uranium 236 (²³⁶U), uranium 238 (²³⁸U), neptunium 237 (²³⁷Np), plutonium 238 (²³⁸Pu), plutonium 239 (²³⁹Pu), plutonium 240 (²⁴⁰Pu), plutonium 244 (²⁴⁴Pu), americium 241 (²⁴¹Am), curium 244 (²⁴⁴Cm), curium 245 (²⁴⁵Cm), curium 248 (²⁴⁸Cm), californium 249 (²⁴⁹Cf), and californium 252 (²⁵²Cf). As used herein, the “m” in ^117m Sn and ^99mTc stands for the meta state. Additionally, naturally-occurring radioactive elements such as uranium, radium, and thorium, which UCDA-42815.601 typically represent mixtures of radioisotopes, are suitable examples of radionuclides. ⁶⁷Cu, ¹³¹I, ¹⁷⁷Lu, and ¹⁸⁶Re are beta- and gamma-emitting radionuclides. ²¹²Bi is an alpha- and beta-emitting radionuclide. ²²⁶Ra is an alpha- and gamma-emitting radionuclide. ²¹¹At, ²¹⁵At, ²¹⁷At, ²¹⁸At, ²⁰⁹Bi, ²¹¹Bi, ²¹³Bi, ²¹⁰Po, ²¹¹Po, ²¹²Po, ²¹⁴Po, ²¹⁵Po, ²¹⁶Po, ²¹⁸Po, ²¹⁸Rn, ²¹⁹Rn, ²²⁰Rn, ²²²Rn, ²²⁶Rn, ²²¹Fr, ²²³Ra, ²²⁴Ra, ²²⁵Ac, ²²⁷Ac, ²²⁷Th, ²²⁸Th, ²²⁹Th, ²³⁰Th, ²³²Th, ²³¹Pa, ²³³U, ²³⁴U, ²³⁵U, ²³⁶U, ²³⁸U, ²³⁷Np, ²³⁸Pu, ²³⁹Pu, ²⁴⁰Pu, ²⁴⁴Pu, ²⁴¹Am, ²⁴⁴Cm, ²⁴⁵Cm, ²⁴⁸Cm, ²⁴⁹Cf, and ²⁵²Cf are examples of alpha-emitting radionuclides. ³H, ³²P, ³⁵S, ⁴⁷Sc, ⁸⁹Sr, ⁹⁰Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁸⁸Re, and ²¹²Pb are examples of beta-emitting radionuclides. ⁶⁷Ga, ¹¹¹In, ^99mTc, ¹³⁷Cs, ²⁰¹Tl, and ²⁰³Pb are examples of gamma-emitting radionuclides. ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁶Ga, ⁶⁸Ga, ⁸²Rb, and ⁸⁶Y are examples of positron- emitting radionuclides. ⁶⁴Cu is a beta- and positron-emitting radionuclide. It is noted that U.S. Provisional Application No.63/625,717, filed January 26, 2024, for which the current patent application claims priority, defined the abbreviation “Ra” as a radionuclide within the recited generic formulas. For purposes of avoiding confusion with the abbreviation for the chemical element “radium” (e.g., Ra), the generic formulas recited herein utilize the abbreviation “RN” for defining radionuclide. As such, “RN” as recited herein is equivalent to “Ra” as recited within the generic formulas recited in U.S. Provisional Application No.63/625,717. The term “subject” or “patient” typically refers to humans, but can also include other animals such as, e.g., other primates, rodents, canines, felines, equines, ovines, porcines, and the like. As used herein, the term “administering” includes oral administration, topical contact, administration as a suppository, intravenous, intraperitoneal, intramuscular, intralesional, intrathecal, intranasal, or subcutaneous administration, or the implantation of a slow-release device, e.g., a mini-osmotic pump, to a subject. Administration is by any route, including parenteral and transmucosal (e.g., buccal, sublingual, palatal, gingival, nasal, vaginal, rectal, or transdermal). Parenteral administration includes, e.g., intravenous, intramuscular, intra-arteriole, intradermal, subcutaneous, intraperitoneal, intraventricular, and intracranial. Other modes of delivery include, but are not limited to, the use of liposomal formulations, intravenous infusion, transdermal patches, etc. By “co-administer” it is meant that a conjugate described herein is administered at the same time, just prior to, or just after the administration of a second agent. UCDA-42815.601 III. RGD Peptides and Conjugates It has been previously demonstrated that uptake of ¹⁷⁷Lu-DOTA-ABM-5G was observed in the kidneys, a dose limiting organ. With the goal to decrease kidney uptake and improve pharmacokinetics of the peptides, experiments conducted during the course of developing embodiments for the present invention resulted in the generation of alternative radionuclides (⁶⁴Cu for imaging, t_1/2 = 12.7 h and ⁶⁷Cu for treatment, t_1/2 = 2.6 d) and different chelators (DOTA and NOTA). Two peptides DOTA-ABM-5G (1) and NOTA-ABM-5G (2) were radiolabeled with ⁶⁴Cu and ⁶⁷Cu to generate ⁶⁴Cu/⁶⁷Cu-DOTA-ABM-5G (⁶⁴Cu/⁶⁷Cu-1) and ⁶⁴Cu/⁶⁷Cu-NOTA-ABM-5G (⁶⁴Cu/⁶⁷Cu-2) and evaluated in vitro for cell binding and serum stability, and in vivo by PET/CT imaging and biodistribution studies. As such, provided herein are therapeutic conjugates (“conjugates”) and related PRRT methods using such therapeutic conjugates for PRRT where the conjugates are configured to bind an αvβ6 integrin. In certain embodiments, conjugates are provided that comprise a peptide selective for binding an αvβ6 integrin. In some embodiments, the peptide is an RGD peptide that is selective for binding αvβ6 integrin. In some embodiments, the peptide comprises the RGD motif, RGDLX₁X₂X₃ (SEQ ID NO:2), wherein X₁ and X₂ are independently selected amino acids, and X3 is L or I. In certain embodiments, the RGD peptide does not comprise any alanine residues. In certain embodiments, the RGD peptide is between 8 and 40 amino acids. In some cases, the RGD peptide is more than 20 amino acids. In some cases, the RGD peptide is 21 amino acids. In certain embodiments, the RGD peptide further comprises QX4VX5RT (SEQ ID NO:7) that is positioned C-terminally to the RGD motif, wherein X4 is R or K and X₅ is A or G. In some cases, the RGD peptide comprises the amino acid sequence QRVGRT (SEQ ID NO:3) positioned C-terminal to the RGD motif. In some cases, the RGD peptide comprises the amino acid sequence RGDLQVLGQRVGRT (SEQ ID NO:4). In certain embodiments, the RGD peptide comprises the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1). In certain embodiments, the RGD peptide consists or consists essentially of the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1). In some embodiments, the conjugate also comprises one or more polyethylene glycol (PEG) moieties covalently attached to the peptide (e.g., RGD peptide). In some cases, the conjugate comprises two PEG moieties, e.g., one PEG moiety is covalently attached to the N-terminus of the peptide and one PEG moiety is covalently attached to the C-terminus of the peptide (e.g., RGD peptide). In certain embodiments, the conjugate comprises the amino UCDA-42815.601 acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with a first PEG moiety covalently attached to the N-terminus of the peptide and a second PEG moiety covalently attached to the C-terminus of the peptide. In some embodiments, the PEG moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some embodiments, the first PEG moiety and the second PEG moiety each have a molecular weight of less than about 5000 daltons (Da), e.g., less than about 3000 Da. In certain embodiments, the first PEG moiety and the second PEG moiety are monodisperse PEG moieties having a defined chain length. Non-limiting examples of PEG moieties having a defined chain length include small, monodisperse PEG molecules having greater than about 95% oligomer purity. In certain instances, the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG11, PEG12 (PEG 800), PEG28 (PEG 1500), and (PEG28)2 (PEG 1500×2). In particular embodiments, the first PEG moiety and the second PEG moiety are the same. In certain embodiments, the first PEG moiety and the second PEG moiety are both PEG28 (PEG 1500). In certain embodiments, the conjugate comprises the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with the N- and C-terminus of the peptide each having a PEG₂₈ (PEG 1500) moiety covalently attached thereto (also referred to herein as “5G”). In some embodiments, the PEG28 (PEG 1500) moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some embodiments, the conjugate includes an albumin binding moiety (ABM) covalently attached to the conjugate. The ABM may increase the half-life of the conjugate in serum, such as when administered to a subject. In some embodiments, the ABM is covalently attached to the peptide (e.g., RGD peptide). In some embodiments having one or two PEG moieties, the ABM is covalently attached to the peptide (e.g., RGD peptide), the first PEG moiety, or the second PEG moiety. In some embodiments, the ABM includes a linker, such as a peptide linker that is covalently attached to the peptide, the first PEG moiety, or the second PEG moiety. In certain embodiments, the ABM comprises 4-(4- iodophenyl)butyric acid (IPA) or a homolog thereof with a shorter alkyl chain such as, e.g., 4-(4-iodophenyl)propionic acid or 4-(4-iodophenyl)acetic acid, or the ABM comprises 4-(4- methylphenyl)butyric acid or 4-(4-bromophenyl)butyric acid or a homolog thereof with a shorter alkyl chain such as, e.g., a propionic acid or acetic acid homolog thereof. In certain instances, the ABM is covalently attached to the first and/or second PEG moiety via a linker such as a glutamic acid (E) linker, a peptide linker such as a lysine-aspartic acid- UCDA-42815.601 aminobutyric acid (K-D-Abu) linker, or other suitable linker (e.g., amino acid or peptide linker) known to one of skill in the art. In certain embodiments, the ABM comprises an ε-(4- (4-iodophenyl)butyl amide)lysine-glutamic acid moiety ("K(IPA)E"), which corresponds to IPA that is covalently attached to the side-chain of the lysine residue of a lysine-glutamic acid peptide linker. In certain other embodiments, the ABM comprises a K(D-Abu- iodophenylbutyryl) moiety, which corresponds to IPA that is covalently attached to the aminobutyric acid of a lysine-aspartic acid-aminobutyric acid (K-D-Abu) peptide linker. In some embodiments, the ABM comprising the K(IPA)E or K(D-Abu-iodophenylbutyryl) moiety is covalently attached to the first PEG moiety. In certain embodiments, the conjugate comprises the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with the N- and C-terminus of the peptide each having a PEG moiety, such as a PEG28 (PEG 1500) moiety, covalently attached thereto, and the conjugate further comprises an ABM covalently attached thereto. In some embodiments, the PEG moiety covalently attached to the C- terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In other embodiments, an imaging agent or therapeutic agent is covalently attached (e.g., via a prosthetic group, a chelating agent, or a linker) to the conjugate. In some embodiments, , an imaging agent or therapeutic agent is covalently attached (e.g., via a prosthetic group, a chelating agent, or a linker) to an albumin binding motif that is covalently attached to the first PEG moiety, such that the imaging agent or therapeutic agent is the most N-terminal moiety in the conjugate. In certain embodiments, the conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with the N- and C-terminus of the peptide each having a PEG moiety, such as a PEG₂₈ (PEG 1500) moiety, covalently attached thereto, an ABM covalently attached to the PEG moiety at the N-terminus of the peptide and a therapeutic agent covalently attached at the N-terminus of the conjugate. In certain embodiments, the conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with the N- and C-terminus of the peptide each having a PEG moiety, such as a PEG₂₈ (PEG 1500) moiety, covalently attached thereto, an ABM covalently attached to the PEG moiety at the N-terminus of the peptide and an imaging agent covalently attached at the N-terminus of the conjugate. In some embodiments, the PEG moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some embodiments, the therapeutic conjugate comprises a therapeutic agent. In some embodiments, the therapeutic agent is a radionuclide such as an alpha-, beta-, and/or UCDA-42815.601 gamma-emitting radionuclide. In some embodiments, the therapeutic conjugate herein comprises a radionuclide such as ³H, ¹⁸F, ³²P, ³⁵S, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, 6⁷Cu, ⁶⁷Ga, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁷Y, ⁸⁹Sr, ⁹⁰Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, ^117mSn, 9^9mTc, ¹³⁷Cs, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²⁰¹Tl, ²¹¹At, ²¹⁵At, ²¹⁷At, ²¹⁸At, ²⁰⁹Bi, a radionuclide such as ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, 1⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Pb, and ²¹²Bi. In particular embodiments, the radionuclide is 1⁷⁷Lu. In particular embodiments, the radionuclide is ⁶⁷Cu. In certain embodiments, the conjugate has the structure of Formula I: ; UCDA-42815.601 wherein RN is a radionuclide; wherein X is either 5G or ABM-5G; wherein 5G is a peptide; and wherein ABM is an albumin binding moiety. In some embodiments, X is ABM-5G such that the resulting therapeutic conjugate is encompassed within Formula II: (Formula II). resulting therapeutic conjugate is encompassed within (Formula III). Such therapeutic and imaging conjugates are not limited to a specific chemical moiety for Ra. In some embodiments, the RN is ⁶⁷Cu or ⁶⁴Cu. In some embodiments, the RN for a therapeutic conjugate is selected from the group consisting of ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, 1¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²¹²Pb and 2²⁵Ac. In other instances, the RN for an imaging conjugate is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, 1¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, and ²⁰³Pb. In other instances, the RN is ¹⁷⁷Lu (therapeutic conjugate) or 6⁸Ga (imaging conjugate). Such therapeutic conjugates are not limited to a specific chemical UCDA-42815.601 moiety for the 5G as a peptide. In some embodiments, the peptide is configured to bind an α_vβ₆ integrin. In some embodiments, the peptide is an RGD peptide configured to bind an αvβ6 integrin. In some embodiments, the peptide is a PEGylated peptide. In some embodiments, the PEGylated peptide has the following amino acid sequence: GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide. In some embodiments, the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG₂₈)₂ (PEG 1500×2). In some embodiments, the first PEG moiety and the second PEG moiety are the same. In some embodiments, the first PEG moiety and the second PEG moiety each comprise PEG28 (PEG 1500). Such conjugates are not limited to a specific chemical moiety for the albumin binding moiety (ABM). In some embodiments, the ABM is a 4-(4-iodophenyl)butyric acid or a K(D- Abu-iodophenylbutyryl) moiety. Such therapeutic conjugates are not limited a specific use or function. In some embodiments, the therapeutic conjugates of Formula I, II, III, or IV are useful for delivering radioactivity to a patient or subject. In some embodiments, the therapeutic conjugates of Formula I, II, III, or IV are useful for treating or preventing cancer in a patient or subject. In some embodiments, the therapeutic conjugates of Formula I, II, III, or IV are useful in treating an αvβ6 integrin-related cancer. In some embodiments, the conjugate has the structure of Formula I, II, III, or IV, wherein 5G is a bi-PEGylated RGD peptide. In some embodiments, the conjugate has the structure of Formula I, II, III, or IV, wherein 5G is a bi-pegylated RGD peptide and the RGD peptide has the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) (e.g., PEG₂₈- GNGVPNLRGDLQVLGQRVGRT-PEG28-C(O)NH2). In some embodiments, the conjugate has the structure of Formula I or III (where X=ABM-5G), and ABM is either a 4-(4-iodophenyl)butyric acid moiety or a K(D-Abu- iodophenylbutyryl) moiety. In certain embodiments, the conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1). In some embodiments, the N- and/or C-terminus of the peptide (e.g., SEQ ID NO: 1) includes a PEG moiety, such as a PEG28 (PEG 1500) moiety. UCDA-42815.601 In some embodiments, the conjugate includes a peptide (e.g., SEQ ID NO: 1) having a PEG moiety covalently attached to the C-terminus of the peptide, wherein the PEG moiety terminates in an amide, a carboxyl group or a hydroxyl group. In some embodiments, the conjugate includes a peptide (e.g., SEQ ID NO: 1) having an N-terminus PEG moiety covalently attached with an ABM. In some embodiments, the conjugate includes 1) a peptide (e.g., SEQ ID NO: 1) having an N-terminus PEG moiety covalently attached with an ABM, and 2) a chelating moiety for complexing a radionuclide. In some aspects, the chelating moiety is a DOTA moiety (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) (e.g., covalently attached to the conjugate). In some embodiments, the chelating moiety is a NOTA moiety (1,4,7- triazacyclononane-N,N′,N″-triacetic acid) (e.g., covalently attached to the conjugate). In some aspects, the chelating moiety of the conjugate is not complexed with a radionuclide. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide (e.g., ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁹Sr, ⁹⁰Y, 1²⁵I, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, . In some aspects, the chelating moiety of the conjugate is complexed the radionuclide is selected for use as a therapeutic agent, such as ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Pb, and ²¹²Bi. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ¹⁷⁷Lu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ⁶⁷Cu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is selected for use as an imaging agent, such as ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, or ²⁰³Pb. In particular embodiments, the radionuclide is ⁶⁴Cu or ⁶⁷Cu. In some embodiments, the radionuclide is ⁶⁴Cu and the conjugate is used for imaging and the radionuclide is ⁶⁷Cu and the conjugate is used for therapy, such as in a theranostic application (i.e., imaging/diagnostic in conjunction with therapy). In certain embodiments, the conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) with the N- and C-terminus of the peptide each having a PEG moiety, such as a PEG28 (PEG 1500) moiety, covalently attached thereto, and a chelating moiety for complexing a radionuclide (e.g., ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ³²P, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹In, ¹¹¹Ag, ¹²⁴I, ¹²⁵I, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²¹²Pb UCDA-42815.601 and ²²⁵Ac). In some embodiments, the PEG moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some aspects, the chelating moiety is a DOTA moiety (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) covalently attached to the conjugate. In some embodiments, the chelating moiety is a NOTA moiety (1,4,7-triazacyclononane-N,N′,N″-triacetic acid) covalently attached to the conjugate. In some aspects, the chelating moiety of the conjugate is not complexed with a radionuclide. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is selected for use as a therapeutic agent, such as ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Pb, ²¹²Bi, and ²²⁵Ac. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ¹⁷⁷Lu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ⁶⁷Cu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is selected for use as an imaging agent, such as ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, or ²⁰³Pb. In particular embodiments, the radionuclide is ⁶⁷Cu or ⁶⁴Cu. In particular embodiments, the radionuclide is ⁶⁷Cu and the conjugate is used as a therapeutic agent. In particular embodiments, the radionuclide is ⁶⁴Cu and the conjugate is used as an imaging agent. In certain embodiments, the conjugate comprises a peptide having the amino acid sequence RGDLX₁X₂X₃ (SEQ ID NO:5), wherein X₁ and X₂ are independently selected amino acids and X3 is L or I (SEQ ID NO:2), or has the amino acid sequence RGDLX1X2X3AQX6 (SEQ ID NO:6), wherein X₆ is K or R , optionally where such peptide is bi-PEGylated (i.e., with the N- and C-terminus of the peptide each having a PEG moiety, such as a PEG28 (PEG 1500) moiety, covalently attached thereto), and a chelating moiety for complexing a radionuclide. In some embodiments, the PEG moiety covalently attached to the C-terminus of the peptide terminates in an amide, a carboxyl group or a hydroxyl group. In some aspects, the chelating moiety is a DOTA moiety (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) covalently attached to the conjugate. In some embodiments, the chelating moiety is a NOTA moiety (1,4,7-triazacyclononane-N,N′,N″-triacetic acid) covalently attached to the conjugate. In some aspects, the chelating moiety of the conjugate is not complexed with a radionuclide. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is selected for use as a therapeutic agent, such as ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, UCDA-42815.601 ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Pb, ²¹²Bi and ²²⁵Ac. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ¹⁷⁷Lu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is ⁶⁷Cu. In some aspects, the chelating moiety of the conjugate is complexed with a radionuclide, and the radionuclide is selected for use as an imaging agent, such as ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, or ²⁰³Pb. In particular embodiments, the radionuclide is ⁶⁷Cu or ⁶⁴Cu. In some embodiments, any of the therapeutic conjugates described herein (e.g., the conjugates encompassed within Formula I, II, III, or IV) are provided in a pharmaceutical composition for administration. In some cases, the pharmaceutical composition comprises one or more unit doses, wherein the amount of radioactivity present in a dose is between about 25 mCi and about 200 mCi. In certain embodiments, the amount of radioactivity present in a dose of the conjugate is between about 25 mCi and about 50 mCi, about 25 mCi and about 100 mCi, about 25 mCi and about 150 mCi, about 25 mCi and about 200 mCi, about 50 mCi and about 100 mCi, about 50 mCi and about 150 mCi, about 50 mCi and about 200 mCi, about 100 mCi and about 150 mCi, about 100 mCi and about 200 mCi, or about 150 mCi and about 200 mCi. In some cases, the amount of radioactivity present in a unit dose is about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi or about 200 mCi. In some embodiments, the amount of peptide in each unit dose of the conjugate is no more than about 500 µg, about 400 µg, about 300 µg, about 200 µg, or about 100 µg of peptide. In some cases, the amount of peptide in each unit dose of the conjugate is no more than about 100 μg of peptide. In other embodiments, each unit dose of the conjugate may be greater than about 100 μg of peptide. In some embodiments, the conjugate is a diagnostic conjugate and comprises a diagnostic agent. In some embodiments, the diagnostic agent is a radionuclide such as a positron-emitting radionuclide. In some embodiments, the diagnostic conjugate herein comprises a radionuclide such as ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Cu, ⁶⁸Ga, ²⁰³Pb, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, or ¹³¹I. In particular embodiments, the radionuclide is ⁶⁴Cu. In some embodiments, the conjugate has the structure of Formula I, II, III, or IV wherein 5G is a bi-PEGylated RGD peptide comprising the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1). In some further preferred embodiments, X is ABM-5G, the 5G peptide is SEQ ID NO:1, and ABM is either 4-(4-iodophenyl)butyric acid or a K(D-Abu-iodophenylbutyryl) moiety, and RN is most preferably ⁶⁴Cu or ⁶⁷Cu. UCDA-42815.601 IV. Methods of Use The methods herein include providing a therapeutically effective dose of a therapeutic conjugate as described herein to a subject. The therapeutic conjugates herein may comprise a radionuclide such as ⁶⁷Cu. In some embodiments, the conjugate has the structure IV), wherein In some embodiments, X is ABM-5G such that the resulting therapeutic conjugate is encompassed within Formula II:

UCDA-42815.601O OH (Formula II). therapeutic conjugate is encompassed within (Formula III). In In some embodiments, the RGD peptide (i.e., found within the conjugate having the structure of Formula I, II, III, or IV) has the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1), such as PEG₂₈-GNGVPNLRGDLQVLGQRVGRT-PEG₂₈-C(O)NH₂. In some embodiments, the RGD peptide (i.e., found within the conjugate having the structure of Formula I, II, III, or IV) has the amino acid sequence RGDLX₁X₂X₃ (SEQ ID NO:5), wherein X₁ and X₂ are independently selected amino acids and X3 is L or I (SEQ ID NO:2), or has the amino acid sequence RGDLX1X2X3AQX6 (SEQ ID NO:6),, wherein X6 is K or R , optionally where such peptide is bi-PEGylated. In some further preferred embodiments, X is AMB-5G and ABM is an albumin binding moiety (e.g., 4-(4-iodophenyl)butyric acid or a K(D-Abu- iodophenylbutyryl) moiety) and RN is a radionuclide In some embodiments, the dose of the therapeutic conjugate administered to a subject contains between about 25 mCi and about 200 mCi radioactivity. In some UCDA-42815.601 embodiments, the dose of the conjugate contains between about 25 mCi and about 100 mCi radioactivity. In some embodiments, the dose of the therapeutic conjugate contains between about 25 mCi and about 150 mCi radioactivity. In some cases, the dose administered contains about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity. In some embodiments, the dose of the therapeutic conjugate does not cause an adverse event (AE) in the subject, such as, e.g., an AE greater than or equal to grade 3 (i.e., severe AE). In some embodiments, the dose (or cumulative doses) of the therapeutic conjugate does not exceed a radiation dose of about 23 Gy to the kidneys and/or a radiation dose of about 1.5 Gy to the bone marrow. The therapeutic conjugate may be administered by infusion, such as over a period of time, such as minutes or hours. In some embodiments, the therapeutic conjugate is infused over a period of minutes, such as about 1 minute, about 2 minutes, about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, or about 55 minutes. In some embodiments, the therapeutic conjugate is infused over a period of about 30 minutes. In some embodiments, the therapeutic conjugate is infused over a period of hours, such as about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, or about 8 hours. In some embodiments, the therapeutic conjugate is infused over a period of about 4 hours. In some embodiments, the therapeutic conjugate is co-infused with a solution of amino acids. In some cases, the infusion of the amino acid solution is commenced prior to the infusion of the therapeutic conjugate. In some embodiments, the therapeutic conjugate is administered to a subject once, twice, three times, four times, or five times over a course of treatment. Subsequent administration of the therapeutic conjugate may occur at defined intervals of time, separated by days, weeks or months. In some cases, the therapeutic conjugate is administered at a subsequent time if the tumor or cancerous cells reappear, continue to grow or otherwise are not fully treated after the first administration of the therapeutic conjugate. In some cases, the therapeutic conjugate is administered again at a subsequent time if the subject does not have a complete response to the first treatment, experiences a partial response, a stable response or progressive disease. In some embodiments, the dosimetry and/or biodistribution of the therapeutic conjugate is evaluated following administration of the therapeutic conjugate to a subject. As a non-limiting example, the dosimetry and biodistribution of the therapeutic conjugate can be evaluated using nuclear imaging at approximately 1 day and/or approximately 7 days (e.g., .5 UCDA-42815.601 days, 1 day, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 21, 28 days) after administration (e.g., infusion) to a subject. In some cases, the subject undergoes whole body planar imaging (e.g., anterior and posterior view) and single photon emission computerized tomography/computed tomography (SPECT/CT) (e.g., skull vertex extending through the perineum, terminating at the proximal thighs; approx.2-4 bed positions) at about 24 and/or about 168 hours following administration of the therapeutic conjugate. In some cases, serial blood samples are drawn at about 5, 15, 30, 60, 120 and/or 180 minutes following administration of the therapeutic conjugate e.g., for evaluation of biodistribution. In some cases, full chemistry, hematology, liver function tests, and/or EKG are performed at about 1 day and/or about 7 days (e.g., ± 48 hours) following administration of the therapeutic conjugate. Methods for dosimetry analysis are known in the art and include, but are not limited to, descriptive statistics (e.g., mean, median, standard deviation, etc.) reported for AUC based on activity concentration-time curves of the therapeutic conjugate (e.g., separately for discernible thoracic and abdominal organs, target lesion, and blood), maximum uptake (e.g., achieved in %) at the target lesion and in discernible organs, specific absorbed dose per organ (μGy/MBq), and cumulative absorbed organ doses (Gy). In some cases, organs receiving the highest absorbed dose assessed by equivalent dose to tissue are tabulated using frequency and proportion. In some cases, graphic tools are used to describe the endpoints. In some embodiments, the distribution of the therapeutic conjugate is determined using whole-body planar SPECT/CT imaging. As a non-limiting example, radiation- absorbed doses to kidneys, stomach, uninvolved liver, bone marrow and the whole body together with any other organs displaying accumulation of the therapeutic conjugate are calculated based on the analysis of serial blood counts and SPECT/CT scans. In some cases, the SPECT/CT images are used to compute the volumetric absorbed radiation dose in the diseased and healthy tissues, e.g., activity concentration-time curves for normal tissues can be generated from region-of-interest (ROI) analysis from the SPECT/CT scans, activity concentration-time curves for red marrow and heart can be generated from blood activity concentration measured by a well scintillation counter, and/or volumes of interest (VOI) can be generated for each patient. In some cases, the activity concentration in red bone marrow is equal to that in blood. In some cases, activity concentration-time curves are integrated (e.g., either analytically or numerically as appropriate) to yield AUC values from which so-called residence times are generated. In some cases, these data are inputted into an organ dosimetry software (e.g., OLINDA/EXM) to generate absorbed dose estimates for normal tissues. In some cases, a supplementary dosimetry assessment is performed including, e.g., lesion UCDA-42815.601 absorbed dose estimates based on image ROI analysis. In some cases, absorbed doses are normalized to administered activity and expressed in terms of mGy/MBq. In some embodiments, the distribution of the therapeutic conjugate in a tumor (e.g., a primary tumor or cancerous lesion), blood, gall bladder, liver, heart, lung, spleen, kidneys, pancreas, stomach, small intestines, bladder, skin, muscle, bone, large intestines, and/or brain of a subject is determined using, e.g., SPECT/CT imaging. In certain embodiments, the amount of the therapeutic conjugate that is present in a non-tumor tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in the non-tumor tissue at one hour after administration of the conjugate. In certain embodiments, the ratio of the amount of the therapeutic conjugate in a tumor to the amount of the therapeutic conjugate in a non-tumor tissue at approximately 24 hours, approximately 48 hours and/or approximately 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the tumor to the amount of the therapeutic conjugate in the non-tumor tissue at 1 hour after administration of the conjugate. In some embodiments, the amount of the therapeutic conjugate that is present in kidney tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in kidney tissue at one hour after administration of the conjugate. In some embodiments, the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in kidney tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in kidney tissue at 1 hour after administration of the conjugate. In some embodiments, the amount of the therapeutic conjugate that is present in stomach tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in stomach tissue at one hour after administration of the conjugate. In some embodiments, the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in stomach tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in stomach tissue at about 1 hour after administration of the conjugate. UCDA-42815.601 In some embodiments, the amount of the therapeutic conjugate that is present in large intestine tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in large intestine tissue at about one hour after administration of the conjugate. In some embodiments, the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in large intestine tissue at about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in large intestine tissue at about 1 hour after administration of the conjugate. In some embodiments, the amount of the therapeutic conjugate in liver tissue is minimal when assayed at about 1 hour, about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate. In some embodiments, the amount of the therapeutic conjugate in a primary tumor is substantially greater when compared to the amount of the therapeutic conjugate in liver tissue at about 1 hour, about 24 hours, about 48 hours and/or about 72 hours after administration of the conjugate. In some embodiments of the methods herein, prior to administration of the therapeutic conjugate, a diagnostic conjugate is administered to the subject. The diagnostic conjugate comprises an RGD peptide that binds an αvβ6 integrin covalently attached (directly or indirectly) to a radionuclide. In some cases, the RGD peptide of the diagnostic conjugate has the same amino acid sequence as the RGD peptide present in the therapeutic conjugate. In some embodiments, the radionuclide of the diagnostic conjugate may have a shorter half- life as compared to the radionuclide of the therapeutic conjugate. In some cases, the radionuclide is ⁶⁴Cu. In some cases, the radionuclide is ⁶⁴Cu for the diagnostic conjugate and the therapeutic conjugate comprises the radionuclide ⁶⁷Cu. In some embodiments, the diagnostic conjugate has the structure of (Formula I) or Formula IV: UCDA-42815.601 (Formula IV), wherein ABM-5G or 5G. In some embodiments, X is ABM-5G such that the resulting therapeutic conjugate is encompassed within Formula II: O OH (Formula II). therapeutic conjugate is encompassed (Formula III). UCDA-42815.601 In some embodiments, the diagnostic conjugate has the structure of Formula I, wherein 5G is a bi-PEGylated RGD peptide. In some embodiments, the RGD peptide (i.e., found within the diagnostic conjugate having the structure of Formula I, II, III, or IV) has the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1), such as PEG₂₈- GNGVPNLRGDLQVLGQRVGRT-PEG28-C(O)NH2. In some further preferred embodiments, X is ABM-5G and AMB is an albumin binding moiety (e.g., 4-(4- iodophenyl)butyric acid or a K(D-Abu-iodophenylbutyryl) moiety). In some embodiments, the methods include administering a diagnostic conjugate of Formula I, II, III, or IV for diagnostic imaging of a tumor, cancerous lesion or cancerous cells. In some embodiments, the methods include administering a diagnostic conjugate of Formula I, II, III, or IV for diagnostic imaging of a tumor, cancerous lesion or cancerous cells and subsequently administering a therapeutic conjugate of Formula I, II, III, or IV to treat the tumor, cancerous lesion or cancerous cells. In some embodiments, the methods include administering a therapeutic conjugate of Formula I, II, III, or IV to treat a cancerous lesion when sufficient lesion uptake (e.g., any visualized lesion with a maximum standardized uptake value (SUVmax) >2-fold above normal lung or liver) of the diagnostic conjugate of Formula I, II,III, or IV is detected. In some embodiments, the diagnostic conjugate is administered by injection. In some embodiments, the diagnostic conjugate is administered by infusion. In some embodiments, the diagnostic conjugate is infused over a period of minutes, such as about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, or less. In some embodiments, the diagnostic conjugate is infused over a period of about 5 minutes or less. In some embodiments, the diagnostic conjugate may be imaged in the body or a portion of the body of the subject. In some embodiments, the uptake and accumulation of the diagnostic conjugate in a lesion, tissue or organ may be used to select subjects for administration of the therapeutic conjugate. In some embodiments, the diagnostic conjugate is utilized to select patients that have an αvβ6 integrin-related lesion or cancer cells and who are eligible for treatment with the therapeutic conjugate. In some embodiments, the diagnostic conjugate is utilized to select patients that have an αvβ6 integrin-related lesion or cancer cells and the selected patients then receive a dose of a therapeutic conjugate, such as the therapeutic conjugate of Formula I, II, III, or IV within 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks or 6 weeks after imaging the diagnostic conjugate. In some embodiments, UCDA-42815.601 the diagnostic conjugate is utilized to select patients that have an α_vβ₆ integrin-related lesion or cancer cells and the selected patients then receive a dose of a therapeutic conjugate, such as the therapeutic conjugate of Formula I, II, III or IV within 4 to 5 weeks after imaging the diagnostic conjugate. In some embodiments, the general distribution of the diagnostic conjugate is determined by blood data and visual analysis of PET/CT scans. As a non-limiting example, reconstructed PET/CT images (e.g., skull apex to proximal-thigh whole body static) can be displayed on an imaging workstation, reoriented into maximum intensity projection (MIP), transaxial, coronal and sagittal images. In certain embodiments, PET, fused PET/CT and/or CT images are reviewed. In some embodiments, regions of interest (ROIs) are placed around tracer avid foci suspicious for malignancy and key organs (e.g., kidney, bladder, intestines, liver, spleen, lung, pancreas) in order to obtain SUV parameters, including SUVmax and SUV mean. In certain instances, SUV measurements are summarized using mean, median, range, and counts, and a repeated measures ANOVA model is used to relate the SUVs to the tissue regions. In some embodiments, “non-excreted” radioactivity and “excreted” radioactivity are tracked, wherein non-excreted radioactivity in the body is calculated from volume-of-interest (VOI) analysis to derive the amount of radioactivity in major organs, tissues of interest and the remainder of the body. In some cases, data are scaled to the “Reference Man” anthropomorphic model for dosimetry purposes. In some cases, organ activity is integrated over time to obtain the time-integrated activity coefficient. In some cases, an organ dosimetry software (e.g., OLINDA/EXM) is used to obtain dose and effective dose measurement. Any device or method known in the art for detecting the radioactive emissions of radionuclides in a subject is suitable for use with the conjugates and methods described herein. For example, methods such as single photon emission computerized tomography (SPECT), which detects the radiation from a single photon gamma-emitting radionuclide using a rotating gamma camera, and radionuclide scintigraphy, which obtains an image or series of sequential images of the distribution of a radionuclide in tissues, organs, or body systems using a scintillation gamma camera, may be used for detecting the radiation emitted from a radiolabeled conjugate described herein. Positron emission tomography (PET) is another suitable technique for detecting radiation in a subject. Furthermore, U.S. Patent No. 5,429,133 describes a laparoscopic probe for detecting radiation concentrated in solid tissue tumors. Miniature and flexible radiation detectors intended for medical use are produced by Intra-Medical LLC (Santa Monica, CA). Furthermore, nuclear magnetic resonance (NMR)- UCDA-42815.601 based methods (e.g., magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI)) or any other imaging technique known to one of skill in the art (including, but not limited to, computed tomography (CT)) may be combined with methods that are suitable for detecting the radioactive emissions of radionuclides. In some embodiments, radiation from a radionuclide is used to determine where the conjugate, such as the diagnostic conjugates described herein, is concentrated in a subject. Regardless of the method or device used, such detection is aimed at determining where the conjugate is concentrated in a subject, with such concentration being an indicator of the location of a tumor or tumor cells. In some embodiments, the therapeutic conjugate (e.g., of Formula I, II, III, or IV) is administered to a subject having cancer, e.g., an αvβ6 integrin-related cancer. Non-limiting examples of different types of cancer suitable for treatment using the therapeutic conjugates described herein include lung cancer, breast cancer, pancreatic cancer, bladder cancer, thyroid cancer, liver cancer, pleural cancer, ovarian cancer, cervical cancer, endometrial cancer, prostate cancer, testicular cancer, colon cancer, colorectal cancer, anal cancer, bile duct cancer, gastrointestinal carcinoid tumors, esophageal cancer, gall bladder cancer, rectal cancer, appendix cancer, small intestine cancer, stomach (gastric) cancer, renal cancer (i.e., renal cell carcinoma), cancer of the central nervous system, skin cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, choriocarcinomas, head and neck cancers, bone cancer, osteogenic sarcomas, fibrosarcoma, neuroblastoma, glioma, melanoma, leukemia (e.g., acute lymphocytic leukemia, chronic lymphocytic leukemia, acute myelogenous leukemia, chronic myelogenous leukemia, or hairy cell leukemia), lymphoma (e.g., non- Hodgkin's lymphoma, Hodgkin's lymphoma, B-cell lymphoma, or Burkitt's lymphoma), and multiple myeloma. In certain embodiments, the cancer is lung cancer, breast cancer, colorectal cancer, pancreatic cancer, ovarian cancer, cervical cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, stomach cancer, or endometrial cancer. In some cases, the subject has a primary lesion (e.g., a primary tumor). In some cases, the subject has a metastasis (e.g., a metastatic form of any of the cancer types described herein). In some cases, the subject has a primary lesion and a metastasis. In some embodiments, the subject has a pancreatic cancer such as locally advanced or metastatic pancreatic cancer, locally advanced, unresectable or metastatic pancreatic adenocarcinoma or pancreatic ductal adenocarcinoma (PDAC). In some embodiments, the subject receives a dose of the therapeutic conjugate of Formula I, II, III, or IV containing between about 25 mCi and about 200 mCi radioactivity, UCDA-42815.601 such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, administered over a period of minutes or hours, such as about 1 minute, about 2 minutes, about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, about 45 minutes, about 55 minutes, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, or about 8 hours. In certain embodiments, the subject receives a dose of the therapeutic conjugate of Formula I, II, III, or IV containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, administered over a period of about 30 minutes. In some embodiments, the subject receives a standard of care treatment prior to the administering of the dose of the therapeutic conjugate. In some aspects, the therapeutic conjugate has the structure of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and prior to such dose, the subject receives a standard of care treatment. The standard of care treatment may comprise one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. The standard of care treatment may comprise FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin). The standard of care treatment may comprise gemcitabine, abraxane or a combination thereof. The standard of care treatment may comprise irinotecan. The standard of care may comprise surgery or surgery and one or more of FOLFIRINOX, gemcitabine, abraxane and irinotecan. In some embodiments, the subject receives a standard of care treatment subsequent to the administering of the dose of the therapeutic conjugate. In some aspects, the therapeutic conjugate has the structure of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and subsequent to such dose, the subject receives a standard of care treatment. The standard of care treatment may comprise one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. The standard of care treatment may comprise FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin). The standard of care treatment may comprise gemcitabine, abraxane or a combination thereof. The standard of care treatment may UCDA-42815.601 comprise irinotecan. The standard of care may comprise surgery or surgery and one or more of FOLFIRINOX, gemcitabine, abraxane and irinotecan. In some embodiments, the subject receives one or more standard of care treatments prior to and subsequent to the administering of the dose of the therapeutic conjugate. In some aspects, the therapeutic conjugate has the structure of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and both prior to and subsequent to such dose, the subject receives a standard of care treatment. The standard of care treatment may comprise one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. The standard of care treatment may comprise FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin). The standard of care treatment may comprise gemcitabine, abraxane or a combination thereof. The standard of care treatment may comprise irinotecan. The standard of care may comprise surgery or surgery and one or more of FOLFIRINOX, gemcitabine, abraxane and irinotecan. The standard of care prior to and subsequent to the treatment with the therapeutic conjugate may be the same. The standard of care prior to and subsequent to the treatment with the therapeutic conjugate may be different from each other. In some embodiments, treatment with the therapeutic conjugate results in stable disease, partial remission or complete remission in the subject (e.g., the methods described herein comprise administering to the subject a dose of the therapeutic conjugate that kills or otherwise slows the growth or progression of cancer cells and leads to stable disease or to partial or complete remission of the cancer in the subject). In some embodiments, treatment with the therapeutic conjugate results in a reduction in metastases of the cancer in the subject (e.g., the methods described herein comprise administering to the subject a dose of the therapeutic conjugate that reduces metastases of the cancer in the subject). In some embodiments, treatment with the therapeutic conjugate results in a reduction in volume, size or growth of a tumor in the subject (e.g., the methods described herein comprise administering to the subject a dose of the therapeutic conjugate that reduces the volume, size or growth of a tumor in the subject). In some embodiments, treatment with the therapeutic conjugate results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent (e.g., the methods described herein comprise administering to the subject a dose of the therapeutic conjugate that increases responsiveness of the cancer to a subsequently administered anti-cancer agent). UCDA-42815.601 In some embodiments, the subject is treated with the therapeutic conjugate of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and the treatment with the therapeutic conjugate results in stable disease, partial remission or complete remission in the subject (e.g., the dose of the therapeutic conjugate kills or otherwise slows the growth or progression of cancer cells and leads to stable disease or to partial or complete remission of the cancer in the subject). In some embodiments, the subject is treated with the therapeutic conjugate of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and the treatment with the therapeutic conjugate results in a reduction in metastases of the cancer in the subject (e.g., the dose of the therapeutic conjugate reduces metastases of the cancer in the subject). In some embodiments, the subject is treated with the therapeutic conjugate of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and the treatment with the therapeutic conjugate results in a reduction in volume, size or growth of a tumor in the subject (e.g., the dose of the therapeutic conjugate reduces the volume, size or growth of a tumor in the subject). In some embodiments, the subject is treated with the therapeutic conjugate of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity, and the treatment with the therapeutic conjugate results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent (e.g., the dose of the therapeutic conjugate increases responsiveness of the cancer to a subsequently administered anti-cancer agent). In some embodiments, the subject has a pancreatic cancer, such as locally advanced, unresectable or metastatic pancreatic adenocarcinoma and the subject is treated with the therapeutic conjugate of Formula I, II, III, or IV and the subject receives a dose of the therapeutic conjugate containing between about 25 mCi and about 200 mCi radioactivity, UCDA-42815.601 such as a dose having about 25 mCi, about 50 mCi, about 100 mCi, about 150 mCi, or about 200 mCi radioactivity. In some aspects, the treatment results in stable disease, partial remission or complete remission in the subject (e.g., the dose of the therapeutic conjugate kills or otherwise slows the growth or progression of cancer cells and leads to stable disease or to partial or complete remission of the cancer in the subject). In some aspects, the treatment results in a reduction in metastases of the pancreatic cancer in the subject (e.g., the dose of the therapeutic conjugate reduces metastases of the cancer in the subject). In some aspects, the treatment results in a reduction in volume, size or growth of a pancreatic tumor in the subject (e.g., the dose of the therapeutic conjugate reduces the volume, size or growth of a tumor in the subject). In some aspects, the treatment results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent, such as a chemotherapeutic agent or a combination thereof (e.g., the dose of the therapeutic conjugate increases responsiveness of the cancer to a subsequently administered anti-cancer agent). In some aspects, the treatment results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent, such as FOLFIRINOX, gemcitabine, abraxane, irinotecan, or any combination thereof. In still further embodiments, the present invention provides methods of treating an αvβ6 integrin-related cancer comprising administering a dose of a therapeutic conjugate to a subject, wherein the therapeutic conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1), wherein the peptide further comprises at a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, a chelating moiety and a radionuclide, most preferably ⁶⁷Cu. In some embodiments, the therapeutic conjugate comprises a chelating moiety. The present invention is not limited to any particular chelating moiety. In some preferred embodiments, the chelating moiety is NOTA, as described above. In other embodiments, the chelating moiety is DOTA. Preferred DOTA conjugates are described in WO2022120226, which is herein incorporated by reference in its entirety. In some embodiments, the conjugate further comprises an albumin binding moiety (ABM). Preferred ABMs are described above. For example, a DOTA conjugate is encompassed within Formula IV: DOTA-ABM-5G; UCDA-42815.601 (Formula IV), In some preferred embodiments, the therapeutic methods comprise administering more than 1 dose of the therapeutic conjugate to the subject. In some particularly preferred embodiments, 2, 3 or 4 doses (or more) are administered during a course of treatment. In some embodiments, the amount of the therapeutic conjugate in the kidney of the subject decreases at least 2-fold within 24 hours after administration of the dose of the therapeutic conjugate. In some aspects of such preferred embodiments, the therapeutic conjugate has the structure of any of Formulas, I, II, III, or IV, and the radionuclide is ⁶⁷Cu. In some particularly preferred embodiments, 2, 3 or 4 doses (or more) are administered during a course of treatment, the conjugate has the structure of Formula II and the radionuclide is ⁶⁷Cu. In some particularly preferred embodiments, 2, 3 or 4 doses (or more) are administered during a course of treatment, the conjugate has the structure of Formula I and the radionuclide is ⁶⁷Cu. In some particularly preferred embodiments, 2, 3 or 4 doses (or more) are administered during a course of treatment, the conjugate has the structure of Formula IV and the radionuclide is ⁶⁷Cu. V. Pharmaceutical Compositions The therapeutic and diagnostic conjugates described herein may be formulated as pharmaceutical compositions for use. Such pharmaceutical compositions may include the conjugate and one or more pharmaceutically-acceptable excipients suitable for injection and/or infusion. UCDA-42815.601 The conjugates herein may be formulated as compositions for administration in the form of a liquid. The liquid can be useful for delivery by injection, such as intratumoral injection, or intravenous infusion. In a composition for administration by injection, one or more of a surfactant, preservative, wetting agent, dispersing agent, suspending agent, buffer, stabilizer (e.g., radioprotectant), and isotonic agent can also be included. The liquid compositions, whether they are solutions, suspensions or other like form, can also include one or more of the following: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils such as synthetic mono or digylcerides which can serve as the solvent or suspending medium, polyethylene glycols, glycerin, cyclodextrin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as amino acids, acetates, citrates or phosphates; detergents, such as nonionic surfactants, polyols; and agents for the adjustment of tonicity such as sodium chloride or dextrose. The liquid compositions may include aqueous or oil suspensions, or emulsions, with sesame oil, corn oil, cottonseed oil, or peanut oil, as well as elixirs, mannitol, dextrose, or a sterile aqueous solution, and similar pharmaceutical vehicles. Aqueous solutions in saline are also conventionally used for injection. Ethanol, glycerol, propylene glycol and liquid polyethylene glycol (and suitable mixtures thereof), cyclodextrin derivatives, and vegetable oils may also be employed. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, for the maintenance of the required particle size in the case of dispersion and by the use of surfactants. The compositions for administration herein are preferably sterile. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid and thimerosal. The compositions for administration of the conjugates herein generally comprise at least one excipient, such as for instance water for infusion, physiologic salt solution (0.9% NaCl), or a cell buffer, preferably consisting of a physiologic salt solution substituted with a protein component such as human serum albumin (HSA). Compositions of the conjugates for administration can be enclosed in ampoule, a disposable syringe or a multiple-dose vial made of glass, plastic or other material. In some cases, the diagnostic conjugate is formulated in 0.9% sodium chloride solution, USP with ≤10% v/v ethanol absolute. In some cases, the therapeutic conjugate is UCDA-42815.601 formulated in 5 mg/mL sodium ascorbate, USP in 0.9% sodium chloride solution, USP with ≤10% v/v ethanol absolute. VI. Examples The following examples are offered to illustrate, but not to limit, the claimed subject matter. Example 1: Therapeutic/Diagnostic Agents METHODS Peptides 1 (DOTA-ABM-5G; 2 by ELISA. The peptides were radiolabeled with copper-64 (⁶⁴Cu) or copper-67 (⁶⁷Cu) in 0.1 M sodium acetate buffer (pH = 6), at 37 °C for 15 min. In vitro cell binding and internalization UCDA-42815.601 were evaluated in the α_vβ₆ (+) human pancreatic cancer Capan-1 cells, and serum stability was evaluated in human serum. PET/CT imaging and biodistribution (4, 24, 48, 72 h) of ⁶⁴Cu-1 and ⁶⁴Cu-2 were performed in female nu/nu mice bearing subcutaneous Capan-1 tumors. RESULTS Peptides 1 and 2 demonstrated high affinity for α_vβ₆ in ELISA (8.4±0.8 and 10.5±1 nM, respectively). Both peptides were radiolabeled successfully with ⁶⁴Cu and ⁶⁷Cu at 0.5 Ci/μmol molar activity, in >98% radiochemical purity (RCP). Rapid binding in vitro (18-35% at 1 h) and internalization (>50% of bound at 1 h) of ⁶⁴Cu-1, ⁶⁴Cu-2, ⁶⁷Cu-1 and ⁶⁷Cu-2 was observed in Capan-1 cells (Fig 1A) and all peptides demonstrated > 95% stability in human serum at 48 h. Capan-1 tumors were clearly visible in the PET/CT images with ⁶⁴Cu-1 and ⁶⁴Cu-2 (Fig 2). Biodistribution studies confirmed uptake and slow washout from tumors over time, %ID/g at 4 h and 72 h: 4.3±0.9 and 2.4±0.2 for ⁶⁴Cu-1; 4.2±0.3 and 2.03±0.2 for ⁶⁴Cu-2 (Fig 3). Both peptides showed clearance from stomach over time, %ID/g at 4 h and 72 h: 12.4±1.7 and 2.9±0.3 for ⁶⁴Cu-1; 12.9±1.2 and 1.5±0.0 for ⁶⁴Cu-2 (Fig 3). Uptake in the kidneys was significantly lower for ⁶⁴Cu-2 than for ⁶⁴Cu-1 (2.4±0.3 vs.5.8±1.0; P = 0.006), resulting in improved tumor-to-kidney ratios of 0.85±0.1 (⁶⁴Cu-2) and 0.43±0.0 (⁶⁴Cu-1) at 72 h.⁶⁴Cu-2 also showed partial hepatobiliary clearance as compared to ⁶⁴Cu-1, %ID/g at 24 h and 72 h: 4.6±0.7 and 2.6±0.4; 1.5±0.2 and 1.4±0.2. The tumor uptake for both ⁶⁴Cu-1 and ⁶⁴Cu-2 is comparable to current radiotherapy peptide ¹⁷⁷Lu-1 (Fig 4A), with improvement in kidney clearance for both ⁶⁴Cu-1 and ⁶⁴Cu-2; %ID/g at 72 h: 10.6±2.7 (¹⁷⁷Lu-1), 5.8±1 (⁶⁴Cu-1) and 2.4±0.3 (⁶⁴Cu-2) (Fig 4). CONCLUSIONS Peptides 1 and 2 showed high affinity for the integrin α_vβ₆ and the radiolabeled peptides ⁶⁴Cu-1, ⁶⁴Cu-2, ⁶⁷Cu-1 and ⁶⁷Cu-2 were synthesized in high RCP. Compared to ¹⁷⁷Lu-DOTA-ABM-5G, ⁶⁴Cu-1 and ⁶⁴Cu-2 show significantly decreased kidney uptake at later time points, while maintaining the uptake in α_vβ₆ (+) tumors in mice. As ⁶⁴Cu/⁶⁷Cu is a “true theranostic” radionuclide pair, it is contemplate that the pharmacokinetics of the imaging peptides (⁶⁴Cu) to match those of the therapy analogs (⁶⁷Cu). Although the modification of the peptide chelator structure from DOTA (1) to NOTA (2) significantly decreased the kidney uptake, an increase in hepatobiliary clearance was also observed. Example 2: Multidosing UCDA-42815.601 Based on the lower exposure of the kidney to the ⁶⁴Cu-containing peptides (see Figure 4), a multi-dosing experiment was undertaken with the therapeutic peptide ⁶⁷Cu-1. BxPC-3 tumor cells were implanted subcutaneously in one flank of female mice aged 6-8 weeks. Tumors were allowed to grow for about 19 days following implantation to 15-50 mm³ volume (Day 0). At day 0, the mice were divided into 3 groups of mice. Group 1 was the control group treated with saline. Group 2 received a single dose of 37 MBq ⁶⁷Cu-1 at Day 0. Group 3 received 4 doses each of 37 MBq ⁶⁷Cu-1 at Day 0, Day 7, Day 14 and Day 28. Average tumor volume was assessed in the animals from Day 0 to Day 42 as shown in Figure 5. The 4-dose group (Group 3) showed a significant decrease in tumor growth as compared to both Group 1 and Group 2. These results indicated that the 67Cu-peptide was therapeutically efficacious and its efficacy could be improved by multi-dose treatment. In view of the unexpected decreased kidney exposure of the ⁶⁴Cu-1 as compared to ¹⁷⁷Lu-1, these results indicate that the selection of copper as the radioligand for therapeutic (and diagnostic/imaging) uses provides an unexpected benefit in ability to treat tumors with multiple doses and to reduce kidney exposure. Exemplary Embodiments Exemplary embodiments provided in accordance with the presently disclosed subject matter include, but are not limited to, the claims and the following embodiments: 1. A method of treating an αvβ6 integrin-related cancer comprising administering a dose of a therapeutic conjugate of Formula I:

UCDA-42815.601 a wherein RN is a radionuclide, wherein X is either 5G or ABM-5G, wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and wherein ABM is an albumin binding moiety; wherein if X is ABM-5G then the resulting therapeutic conjugate is encompassed within Formula II: UCDA-42815.601 ; within (Formula III). 2. The method of embodiment 1, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ³²P, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹¹¹In, ¹²⁴I, ¹²⁵I, or ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²⁰³Pb, ²¹²Pb, ²²⁵Ac. 3. The method of embodiment 1, wherein the radionuclide is ⁶⁴Cu. 4. The method of any one of embodiments 1-3, wherein the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and (PEG₂₈)₂ (PEG 1500x2). UCDA-42815.601 5. The method of any one of embodiments 1-4, further comprising administering one or more additional dose(s) of the therapeutic conjugate to the subject. 6. The method of any one of embodiments 1-5, wherein the dose includes no more than about 100 µg of the peptide. 7. The method of any one of embodiments 1-6, wherein the α_vβ₆ integrin- related cancer is a solid tumor, pancreatic cancer, breast cancer, colorectal cancer, lung cancer, ovarian cancer, cervical cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, stomach cancer, or endometrial cancer. 8. The method of embodiment 7, wherein the pancreatic cancer is locally advanced or metastatic pancreatic cancer; locally advanced, unresectable or metastatic pancreatic adenocarcinoma; or pancreatic ductal adenocarcinoma (PDAC). 9. The method of any one of embodiments 1-8, wherein the α_vβ₆ integrin- related cancer comprises a primary lesion and a metastatic lesion. 10. The method of any one of embodiments 1-9, wherein the αvβ6 integrin- related cancer comprises a lesion in an adrenal gland, bone, brain, liver, lung or any combination thereof. 11. The method of any one of embodiments 1-10, wherein the subject receives a standard of care treatment prior to the administering of the dose of the therapeutic conjugate. 12. The method of any one of embodiments 1-11, wherein the subject receives a standard of care treatment subsequent to the administering of the dose of the therapeutic conjugate. 13. The method of embodiment 11 or 12, wherein the standard of care treatment comprises one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. 14. The method of any one of embodiments 11-13, wherein the standard of care treatment comprises FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, UCDA-42815.601 irinotecan hydrochloride and oxaliplatin), gemcitabine, abraxane, irinotecan, or a combination thereof. 15. The method of any one of embodiments 1-14, wherein the method further comprises scanning the body of the subject or a portion thereof after administering the therapeutic conjugate. 16. The method of embodiment 15, wherein the scanning comprises positron emission tomography (PET), computed tomography (CT) scanning, or single photon emission computerized tomography (SPECT). 17. The method of any one of embodiments 1-16, further comprising administering a diagnostic conjugate prior to the administration of the therapeutic conjugate, wherein the diagnostic conjugate comprises an RGD peptide and a second radionuclide. 18. The method of embodiment 17, wherein the second radionuclide is ⁶⁴Cu. 19. The method of embodiment 17 or 18, wherein the diagnostic conjugate is administered in a dose that contains up to about 5 mCi radioactivity. 20. The method of any one of embodiments 17-19, wherein the method further comprises scanning the body of the subject or a portion thereof after administering the diagnostic conjugate. 21. The method of embodiment 20, wherein the scanning comprises positron emission tomography (PET), computed tomography (CT) scanning, or single photon emission computerized tomography (SPECT). 22. The method of any one of embodiments 17-21, wherein the therapeutic conjugate is administered within 5 weeks after the administration of the diagnostic conjugate.

UCDA-42815.601 23. The method of any one of embodiments 17-22, wherein the diagnostic conjugate comprises: a subject in need of treatment, wherein RN is a radionuclide, preferably ⁶⁴Cu, wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and wherein ABM is an albumin binding moiety. 24. The method of embodiment 23, wherein the first PEG moiety and the second PEG moiety each comprises PEG28 (PEG 1500). 25. The method of any one of embodiments 1-24, further comprising administering a solution of amino acids to the subject. 26. The method of embodiment 25, wherein the solution is administered prior to and concurrent with the administration of the therapeutic conjugate. 27. The method of any one of embodiments 1-26, wherein the therapeutic conjugate is administered to the subject by infusion. 28. The method of any one of embodiments 18-27, wherein the diagnostic conjugate is administered to the subject by injection. 29. The method of any one of embodiments 1-28, wherein the treatment results in stable disease, partial remission or complete remission. UCDA-42815.601 30. The method of any one of embodiments 1-29, wherein the treatment results in a reduction in metastases of the cancer in the subject. 31. The method of any one of embodiments 1-30, wherein the treatment results in a reduction in volume, size or growth of a tumor in the subject. 32. The method of any one of embodiments 1-31, wherein the treatment results in an increased responsiveness of the cancer to a subsequently administered anti- cancer agent. 33. The method of any one of embodiments 1-32, wherein the amount of the therapeutic conjugate that is present in kidney tissue at about 24 hours, about 48 hours or about 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in kidney tissue at one hour after administration of the conjugate. 34. The method of any one of embodiments 1-33, wherein the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in kidney tissue at about 24 hours, about 48 hours or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in kidney tissue at 1 hour after administration of the conjugate. 35. A pharmaceutical composition comprising a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) covalently attached to a NOTA (2,2′,2”-(1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid) moiety. 36. The pharmaceutical composition of embodiment 35, wherein a PEG moiety is covalently attached at the N-terminus, the C-terminus or both the N- and C-termini of the peptide. 37. The pharmaceutical composition of embodiment 36, wherein the PEG moiety is independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG28 (PEG 1500), and/or (PEG28)2 (PEG 1500×2). 38. The pharmaceutical composition of embodiment 36, wherein a first PEG moiety is covalently attached to the N-terminus of the peptide and a second PEG moiety UCDA-42815.601 is covalently attached to the C-terminus of the peptide, and the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG28 (PEG 1500), and/or (PEG28)2 (PEG 1500×2). 39. The pharmaceutical composition of embodiment 37, wherein the first PEG moiety and the second PEG moiety are the same. 40. The pharmaceutical composition of embodiment 38, wherein the first PEG moiety and the second PEG moiety each comprises PEG₂₈ (PEG 1500). 41. The pharmaceutical composition of any one of embodiments 35-40, wherein the peptide is covalently attached to an albumin binding moiety (ABM). 42. The pharmaceutical composition of embodiment 41, wherein the ABM comprises 4-(4-iodophenyl)butyric acid. 43. The pharmaceutical composition of embodiment 41, wherein the ABM comprises a K(D-Abu-iodophenylbutyryl) moiety. 44. The pharmaceutical composition of any one of embodiments 35-43, wherein a radionuclide is complexed with the NOTA moiety. 45. The pharmaceutical composition of any one of embodiments 35-43, wherein a radionuclide is covalently attached directly or indirectly to the peptide. 46. The pharmaceutical composition of embodiments 44 or 45, wherein the radionuclide is selected from the group consisting of ³²P, ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²¹²Pb and ²²⁵Ac. 47. The pharmaceutical composition of embodiments 44 or 45, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, or ²⁰³Pb. UCDA-42815.601 48. A pharmaceutical composition comprising a conjugate of Formula I: (Formula IV); ABM-5G; wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and further optionally wherein ABM is an albumin binding moiety; and a pharmaceutically acceptable excipient; wherein if X is ABM-5G then the resulting therapeutic conjugate is encompassed within Formula II: (Formula II); UCDA-42815.601 wherein if X is 5G then the resulting therapeutic conjugate is encompassed within (Formula III). 49. The pharmaceutical composition of embodiment 48, wherein the first PEG moiety and the second PEG moiety are the same. 50. The pharmaceutical composition of embodiment 48 or 49, wherein the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and (PEG₂₈)₂ (PEG 1500x2). 51. A method for the in vivo imaging of a target tissue, the method comprising: (a) administering a conjugate comprising a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) covalently attached to a NOTA (2,2′,2”- (1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid) moiety to a subject, wherein a radionuclide is complexed with the NOTA moiety; and (b) detecting the conjugate to determine where the conjugate is concentrated in the subject. 52. The method of embodiment 51, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ³²P, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹¹¹In, ¹²⁴I, ¹²⁵I, or ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²¹²Pb, ²²⁵Ac. UCDA-42815.601 53. The method of embodiments 51 or 52, wherein the target tissue is a cancerous tissue or an organ. 54. The method of any one of embodiments 51 to 53, wherein the imaging agent is a radionuclide, and wherein radiation from the radionuclide is used to determine where the conjugate is concentrated in the subject. 55. The method of any one of embodiments 51 to 54, wherein the conjugate is detected by Magnetic Resonance Imaging (MRI), Magnetic Resonance Spectroscopy (MRS), Single Photon Emission Computerized Tomography (SPECT), Positron Emission Tomography (PET), or optical imaging. 56. The method of any one of embodiments 51 to 55, wherein the conjugate is detected for the diagnosis or prognosis of a disease or disorder mediated by the integrin. 57. The method of embodiment 56, wherein the disease or disorder is associated with the expression, overexpression, or activation of the integrin. 58. The method of embodiment 56 or 57, wherein the disease or disorder is an αvβ6 integrin-mediated disease or disorder. 59. A method of treating an α_vβ₆ integrin-related cancer comprising administering a dose of a therapeutic conjugate to a subject, wherein the therapeutic conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1), wherein the peptide further comprises a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, a chelating moiety and a radionuclide, wherein the radionuclide is ⁶⁷Cu. 60. The method of embodiment 59, wherein the therapeutic conjugate further comprises an albumin binding moiety. UCDA-42815.601 61. The method of embodiment 59 or claim 60, wherein the chelating moiety is NOTA or DOTA. 62. The method of any one of embodiments 59-61, wherein the method comprises administering more than one dose of the therapeutic conjugate to the subject. 63. The method of embodiment 61, wherein 2, 3 or 4 doses of the therapeutic are administered to the subject. 64. The method of any one of embodiments 59-63, wherein the amount of the therapeutic conjugate in a kidney of the subject decreases at least 2-fold within about 24 hours after administration of the dose of the therapeutic conjugate. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, patent applications, and sequence accession numbers cited herein are hereby incorporated by reference in their entirety for all purposes.

Claims

UCDA-42815.601 WHAT IS CLAIMED IS: 1. A method of treating an αvβ6 integrin-related cancer comprising administering a dose of a therapeutic conjugate of (Formula I) to a subject in need of wherein RN is a radionuclide (preferably ⁶⁷Cu); wherein X is either 5G or ABM- 5G; wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and further optionally wherein ABM is an albumin binding moiety; wherein if X is ABM-5G then the resulting therapeutic conjugate is encompassed within Formula II: (Formula II); UCDA-42815.601 wherein if X is 5G then the resulting therapeutic conjugate is encompassed within (Formula III). 2. The method of claim 1, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ³²P, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, 3. The method of claim 1, wherein the radionuclide is ⁶⁷Cu. 4. The method of any one of claims 1-3, wherein the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG11, PEG12 (PEG 800), PEG₂₈ (PEG 1500), and (PEG₂₈)₂ (PEG 1500x2). 5. The method of any one of claims 1-4, further comprising administering one or more additional dose(s) of the therapeutic conjugate to the subject. 6. The method of any one of claims 1-5, wherein the dose includes no more than about 100 µg of the peptide. 7. The method of any one of claims 1-6, wherein the α_vβ₆ integrin-related cancer is a solid tumor, pancreatic cancer, breast cancer, colorectal cancer, lung cancer, ovarian cancer, cervical cancer, oral squamous cell carcinoma, skin squamous cell carcinoma, stomach cancer, or endometrial cancer. UCDA-42815.601 8. The method of claim 7, wherein the pancreatic cancer is locally advanced or metastatic pancreatic cancer; locally advanced, unresectable or metastatic pancreatic adenocarcinoma; or pancreatic ductal adenocarcinoma (PDAC). 9. The method of any one of claims 1-8, wherein the αvβ6 integrin-related cancer comprises a primary lesion and a metastatic lesion. 10. The method of any one of claims 1-9, wherein the α_vβ₆ integrin-related cancer comprises a lesion in an adrenal gland, bone, brain, liver, lung or any combination thereof. 11. The method of any one of claims 1-10, wherein the subject receives a standard of care treatment prior to the administering of the dose of the therapeutic conjugate. 12. The method of any one of claims 1-11, wherein the subject receives a standard of care treatment subsequent to the administering of the dose of the therapeutic conjugate. 13. The method of claim 11 or 12, wherein the standard of care treatment comprises one or more of surgery, radiation therapy, chemotherapy, chemoradiation therapy and targeted therapy. 14. The method of any one of claims 11-13, wherein the standard of care treatment comprises FOLFIRINOX (leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin), gemcitabine, abraxane, irinotecan, or a combination thereof. 15. The method of any one of claims 1-14, wherein the method further comprises scanning the body of the subject or a portion thereof after administering the therapeutic conjugate. 16. The method of claim 15, wherein the scanning comprises positron emission tomography (PET), computed tomography (CT) scanning, magnetic resonance imaging (MRI), or single photon emission computerized tomography (SPECT). 17. The method of any one of claims 1-16, further comprising administering a diagnostic conjugate prior to the administration of the therapeutic conjugate, wherein the diagnostic conjugate comprises an RGD peptide and a second radionuclide. 18. The method of claim 17, wherein the second radionuclide is ⁶⁴Cu. UCDA-42815.601 19. The method of claim 17 or 18, wherein the diagnostic conjugate is administered in a dose that contains up to about 5 mCi radioactivity. 20. The method of any one of claims 17-19, wherein the method further comprises scanning the body of the subject or a portion thereof after administering the diagnostic conjugate. 21. The method of claim 20, wherein the scanning comprises positron emission tomography (PET), computed tomography (CT) scanning, or single photon emission computerized tomography (SPECT). 22. The method of any one of claims 17-21, wherein the therapeutic conjugate is administered within 5 weeks after the administration of the diagnostic conjugate. 23. The method of any one of claims 17-22, wherein the diagnostic conjugate comprises Formula II: (Formula II) to a subject in need wherein RN is a radionuclide, preferably ⁶⁴Cu, wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and further optionally wherein ABM is an albumin binding moiety. 24. The method of claim 23, wherein the first PEG moiety and the second PEG moiety each comprises PEG₂₈ (PEG 1500). UCDA-42815.601 25. The method of any one of claims 1-24, further comprising administering a solution of amino acids to the subject. 26. The method of claim 25, wherein the solution is administered prior to and concurrent with the administration of the therapeutic conjugate. 27. The method of any one of claims 1-26, wherein the therapeutic conjugate is administered to the subject by infusion. 28. The method of any one of claims 18-27, wherein the diagnostic conjugate is administered to the subject by injection. 29. The method of any one of claims 1-28, wherein the treatment results in stable disease, partial remission or complete remission. 30. The method of any one of claims 1-29, wherein the treatment results in a reduction in metastases of the cancer in the subject. 31. The method of any one of claims 1-30, wherein the treatment results in a reduction in volume, size or growth of a tumor in the subject. 32. The method of any one of claims 1-31, wherein the treatment results in an increased responsiveness of the cancer to a subsequently administered anti-cancer agent. 33. The method of any one of claims 1-32, wherein the amount of the therapeutic conjugate that is present in kidney tissue at approximately 24 hours, approximately 48 hours or approximately 72 hours after administration of the conjugate is lower than the amount of the therapeutic conjugate that is present in kidney tissue at one hour after administration of the conjugate. 34. The method of any one of claims 1-33, wherein the ratio of the amount of the therapeutic conjugate in a primary tumor to the amount of the therapeutic conjugate in kidney tissue at about 24 hours, about 48 hours or about 72 hours after administration of the conjugate is higher than the ratio of the amount of the therapeutic conjugate in the primary tumor to the amount of the therapeutic conjugate in kidney tissue at 1 hour after administration of the conjugate. UCDA-42815.601 35. A pharmaceutical composition comprising a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) covalently attached to a NOTA (2,2′,2”- (1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid) moiety. 36. The pharmaceutical composition of claim 35, wherein a PEG moiety is covalently attached at the N-terminus, the C-terminus or both the N- and C-termini of the peptide. 37. The pharmaceutical composition of claim 36, wherein the PEG moiety is independently selected from the group consisting of PEG₁₁, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG28)2 (PEG 1500×2). 38. The pharmaceutical composition of claim 36, wherein a first PEG moiety is covalently attached to the N-terminus of the peptide and a second PEG moiety is covalently attached to the C-terminus of the peptide, and the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG11, PEG12 (PEG 800), PEG₂₈ (PEG 1500), and/or (PEG₂₈)₂ (PEG 1500×2). 39. The pharmaceutical composition of claim 37, wherein the first PEG moiety and the second PEG moiety are the same. 40. The pharmaceutical composition of claim 38, wherein the first PEG moiety and the second PEG moiety each comprises PEG28 (PEG 1500). 41. The pharmaceutical composition of any one of claims 35-40, wherein the peptide is covalently attached to an albumin binding moiety (ABM). 42. The pharmaceutical composition of claim 41, wherein the ABM comprises 4-(4- iodophenyl)butyric acid. 43. The pharmaceutical composition of claim 41, wherein the ABM comprises a K(D- Abu-iodophenylbutyryl) moiety. 44. The pharmaceutical composition of any one of claims 35-43, wherein a radionuclide is complexed with the NOTA moiety. 45. The pharmaceutical composition of any one of claims 35-43, wherein a radionuclide is covalently attached directly or indirectly to the peptide. UCDA-42815.601 46. The pharmaceutical composition of claims 44 or 45, wherein the radionuclide is selected from the group consisting of ⁴⁷Sc, ⁶⁷Cu, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²¹²Pb and ²²⁵Ac. 47. The pharmaceutical composition of claims 44 or 45, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ¹¹¹In, ¹²⁴I, ¹²⁵I, ¹³¹I, or ²⁰³Pb. 48. A pharmaceutical composition comprising a conjugate of Formula I: (Formula I); ⁶⁷Cu); wherein X is either 5G or ABM-5G; wherein 5G is a PEGylated peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) and comprising a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, and further optionally wherein ABM is an albumin binding moiety; and a pharmaceutically acceptable excipient; wherein if X is ABM-5G then the resulting therapeutic conjugate is encompassed within Formula II:

UCDA-42815.601 (Formula II); and conjugate is encompassed within (Formula III).

UCDA-42815.601 49. The pharmaceutical composition of claim 48, wherein the first PEG moiety and the second PEG moiety are the same. 50. The pharmaceutical composition of claim 48 or 49, wherein the first PEG moiety and the second PEG moiety are independently selected from the group consisting of PEG11, PEG₁₂ (PEG 800), PEG₂₈ (PEG 1500), and (PEG₂₈)₂ (PEG 1500x2). 51. A method for the in vivo imaging of a target tissue, the method comprising: (a) administering a conjugate comprising a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1) covalently attached to a NOTA (2,2′,2”- (1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid) moiety to a subject, wherein a radionuclide is complexed with the NOTA moiety; and (b) detecting the conjugate to determine where the conjugate is concentrated in the subject. 52. The method of claim 51, wherein the radionuclide is selected from the group consisting of ¹¹C, ¹³N, ¹⁵O, ¹⁸F, ³²P, ⁴⁷Sc, ⁵⁵Co, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁷Cu, ⁶⁸Ga, ⁸²Rb, ⁸⁶Y, ⁸⁹Sr, ⁹⁰Y, ¹⁰⁵Rh, ¹¹¹Ag, ^117mSn, ¹¹¹In, ¹²⁴I, ¹²⁵I, or ¹³¹I, ¹⁴⁹Pm, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ²¹¹At, ²¹²Bi, ²⁰³Pb, ²¹²Pb, ²²⁵Ac. 53. The method of claims 51 or 52, wherein the target tissue is a cancerous tissue or an organ. 54. The method of any one of claims 51 to 53, wherein the imaging agent is a radionuclide, and wherein radiation from the radionuclide is used to determine where the conjugate is concentrated in the subject. 55. The method of any one of claims 51 to 54, wherein the conjugate is detected by Magnetic Resonance Imaging (MRI), Magnetic Resonance Spectroscopy (MRS), Single Photon Emission Computerized Tomography (SPECT), Positron Emission Tomography (PET), or optical imaging. 56. The method of any one of claims 51 to 55, wherein the conjugate is detected for the diagnosis or prognosis of a disease or disorder mediated by the integrin. UCDA-42815.601 57. The method of claim 56, wherein the disease or disorder is associated with the expression, overexpression, or activation of the integrin. 58. The method of claim 56 or 57, wherein the disease or disorder is an αvβ6 integrin- mediated disease or disorder. 59. A method of treating an α_vβ₆ integrin-related cancer comprising administering a dose of a therapeutic conjugate to a subject, wherein the therapeutic conjugate comprises a peptide having the amino acid sequence GNGVPNLRGDLQVLGQRVGRT (SEQ ID NO:1), wherein the peptide further comprises a first PEG moiety at the N-terminus of the peptide and a second PEG moiety at the C-terminus of the peptide, a chelating moiety and a radionuclide, wherein the radionuclide is ⁶⁷Cu. 60. The method of claim 59, wherein the therapeutic conjugate further comprises an albumin binding moiety. 61. The method of claim 59 or claim 60, wherein the chelating moiety is NOTA or DOTA. 62. The method of any one of claims 59-61, wherein the method comprises administering more than one dose of the therapeutic conjugate to the subject. 63. The method of claim 61, wherein 2, 3 or 4 doses of the therapeutic conjugate are administered to the subject. 64. The method of any one of claims 59-63, wherein the amount of the therapeutic conjugate in a kidney of the subject decreases at least 2-fold within about 24 hours after administration of the dose of the therapeutic conjugate. 65. The method of any one of claims 59-64, wherein the conjugate has the structure of Formula I. UCDA-42815.601 66. The method of any one of claims 59-64, wherein the conjugate has the structure of Formula II. 67. The method of any one of claims 59-64, wherein the conjugate has the structure of Formula III. 68. The method of any one of claims 59-64, wherein the conjugate has the structure of Formula IV. 69. The method of any one of claims 59-64, further comprising imaging a tumor or tumor cells in the subject with an imaging agent, wherein the imaging agent comprises Formula I, optionally wherein the radionuclide is ⁶⁴Cu.