Polymers useful for conjugating to antibodies and therapeutic uses thereof

Abstract

Polymer compounds useful for preparing antibody-drug conjugates are disclosed. The polymers contain a side chain-carrying deoxyuridine group. Methods associated with preparation and use of such compounds are also provided.

Description

[0001] POLYMERS USEFUL FOR CONJUGATING TO ANTIBODIES AND THERAPEUTIC USES THEREOF BACKGROUND Technical Field Embodiments of the present disclosure are generally directed to polymeric compounds useful with antibodies to form antibody-drug conjugates, as well as methods of making and using the same. Description of the Related Art Antibody-drug conjugates (ADCs) are a simple, but elegant disease therapy. ADCs offer a strategy for cancer therapy whereby a potent cytotoxic agent is delivered to tumor cells with minimal damage to normal cells. However, this strategy is not without its challenges. Despite their antibody-directed cellular targeting, these agents come with their share of toxicity. Careful planning with respect to choices of payloads, linkers, and antibodies is needed to develop valuable therapeutic assets. Thus, there exists a need in the art for developing new therapies that function to treat diseases (e.g., cancer) in a targeted manner. The present disclosure fulfills this need and provides further related advantages. BRIEF SUMMARY The present disclosure provides compounds that are new therapeutic compounds that are useful because they can be efficiently conjugated to antibody molecules. Their structures have several important features, including the ability to fine tune the overall physical characteristics of the linker-drug molecules. Namely, synthetic methods (e.g., modified DNA synthesis methods) used to produce these molecules are amenable to precise control and ease of design. The backbone structure of these molecules includes moieties that effect the overall water solubility of the molecule and by proximity, the ADC. Additionally, the water solubility is a characteristic that can be increased or decreased based on backbone length and composition. Accordingly, one embodiment provides a (polymer) compound having the following Structure (I): or a salt, stereoisomer, or tautomer thereof, wherein R1, R2, L1, L2, L3, L4, n, m, p, v, and w are as defined herein. Polymer compounds of Structure (I) find utility in several applications, including use as therapeutic agents for various treatment methods. In another embodiment, a conjugate is provided which comprises a compound of Structure (I) covalently bound to an antibody or a toxin. In another embodiment, compositions are provided which comprise a compound of Structure (I) and a pharmaceutically acceptable carrier or the conjugate comprising a polymer compound of the present disclosure and a pharmaceutically acceptable carrier. In yet another embodiment, a method of treating a disease is provided, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound of Structure (I), a composition comprising a compound of Structure (I), a compound of Structure (I) conjugated to an antibody, or a composition comprising a compound of Structure (I) conjugated to an antibody. These and other aspects of the disclosure will be apparent upon reference to the following detailed description. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG.1 is a representative chemical structure of Structure (I), specifically compound Mal- HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT. FIG.2 is a cytotoxicity dose-response graphs of the compounds in the present disclosure. DETAILED DESCRIPTION It is important to note that a compound of Structure (I) can be synthesized in a way that allows precise control of the number of charged moieties per molecule. Additionally, polymer compounds can be made such that there is optimum space and flexibility between moieties. In the following description, certain specific details are set forth to provide a thorough understanding of various embodiments of the disclosure. However, one skilled in the art will understand that the disclosure may be practiced without these details. Unless the context requires otherwise, throughout the present specification and claims, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense, that is, as "including, but not limited to". Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. "Amino" refers to the ˗NH2group. "Carboxy" refers to the ˗CO2H group. "Cyano" refers to the ˗CN group. "Hydroxy" or "hydroxyl" refers to the ˗OH group. "Nitro" refers to the ˗NO2group. "Oxo" refers to the =O substituent group. "Sulfhydryl" refers to the ˗SH group. "Thioxo" refers to the =S group. "Alkyl" refers to a straight or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to twelve carbon atoms (C1-C12alkyl), one to eight carbon atoms (C1-C8alkyl) or one to six carbon atoms (C1-C6alkyl), and which is attached to the rest of the molecule by a single bond, e.g., methyl, ethyl, n-propyl, 1-methylethyl (iso-propyl), n-butyl, n-pentyl, 1,1-dimethylethyl (t-butyl), 3-methylhexyl, 2-methylhexyl, and the like. Unless stated otherwise specifically in the specification, alkyl groups are optionally substituted. "Alkylene" or "alkylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing no unsaturation, and having from one to twelve carbon atoms, e.g., methylene, ethylene, propylene, n-butylene, ethenylene, propenylene, n-butenylene, propynylene, n-butynylene, and the like. The alkylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alkylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkylene is optionally substituted. "Alkenylene" or "alkenylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon double bond, and having from two to twelve carbon atoms, e.g., ethenylene, propenylene, n-butenylene, and the like. The alkenylene chain is attached to the rest of the molecule through a single bond and to the radical group through a double bond or a single bond. The points of attachment of the alkenylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkenylene is optionally substituted. "Alkynylene" or "alkynylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon triple bond, and having from two to twelve carbon atoms, e.g., ethenylene, propenylene, n-butenylene, and the like. The alkynylene chain is attached to the rest of the molecule through a single bond and to the radical group through a double bond or a single bond. The points of attachment of the alkynylene chain to the rest of the molecule and to the radical group can be through one carbon or any two carbons within the chain. Unless stated otherwise specifically in the specification, alkynylene is optionally substituted. "Alkylether" refers to any alkyl group as defined above, wherein at least one carbon- carbon bond is replaced with a carbon-oxygen bond. The carbon-oxygen bond may be on the terminal end (as in an alkoxy group) or the carbon oxygen bond may be internal (i.e., C-O-C). Alkylethers include at least one carbon oxygen bond but may include more than one. For example, polyethylene glycol (PEG) is included within the meaning of alkylether. Unless stated otherwise specifically in the specification, an alkylether group is optionally substituted. For example, in some embodiments an alkylether is substituted with an alcohol or ˗OP(=Ra)(Rb)Rc, wherein each of Ra, Rb and Rc is as defined for polymer compounds of the present disclosure (e.g., compounds of Structure (I)). "Alkoxy" refers to a group of the formula ˗ORa where Ra is an alkyl group as defined above containing one to twelve carbon atoms. Unless stated otherwise specifically in the specification, an alkoxy group is optionally substituted. "Alkoxyalkylether" refers to a group of the formula ˗ORaRbwhere Rais an alkylene group as defined above containing one to twelve carbon atoms, and Rb is an alkylether group as defined herein. Unless stated otherwise specifically in the specification, an alkoxyalkylether group is optionally substituted, for example substituted with an alcohol or ˗OP(=Ra)(Rb)Rc, wherein each of Ra, Rband Rcis as defined for polymer compounds of the present disclosure (e.g., compounds of Structure (I)). "Heteroalkyl" refers to an alkyl group, as defined above, comprising at least one heteroatom (e.g., N, O, P or S) within the alkyl group or at a terminus of the alkyl group. In some embodiments, the heteroatom is within the alkyl group (i.e., the heteroalkyl comprises at least one carbon-[heteroatom]x-carbon bond, where x is 1, 2 or 3). In other embodiments, the heteroatom is at a terminus of the alkyl group and thus serves to join the alkyl group to the remainder of the molecule (e.g., M1-H-A), where M1 is a portion of the molecule, H is a heteroatom and A is an alkyl group). Unless stated otherwise specifically in the specification, a heteroalkyl group is optionally substituted. Exemplary heteroalkyl groups include ethylene oxide (e.g., polyethylene oxide), optionally including phosphorous-oxygen bonds, such as phosphodiester bonds. "Heteroalkoxy" refers to a group of the formula ˗ORawhere Rais a heteroalkyl group as defined above containing one to twelve carbon atoms. Unless stated otherwise specifically in the specification, a heteroalkoxy group is optionally substituted. "Heteroalkylene" refers to an alkylene group, as defined above, comprising at least one heteroatom (e.g., Si, N, O, P or S) within the alkylene chain or at a terminus of the alkylene chain. In some embodiments, the heteroatom is within the alkylene chain (i.e., the heteroalkylene comprises at least one carbon-[heteroatom]-carbon bond, where x is 1, 2 or 3). In other embodiments, the heteroatom is at a terminus of the alkylene and thus serves to join the alkylene to the remainder of the molecule (e.g., M1-H-A-M2, where M1and M2are portions of the molecule, H is a heteroatom and A is an alkylene). Unless stated otherwise specifically in the specification, a heteroalkylene group is optionally substituted. Exemplary heteroalkylene groups include ethylene oxide (e.g., polyethylene oxide) and the "C," "HEG," and "PEG 1K" linking groups illustrated below: "C linker" "HEG linker" "PEG 1K linker" Multimers of the above C-linker, HEG linker and / or PEG 1K linker are included in various embodiments of heteroalkylene linkers. In some embodiments of the PEG 1K linker, n ranges from 19-25, for example n is 19, 20, 21, 22, 23, 24, or 25. Multimers may comprise, for example, the following structure: wherein x is 0 or an integer greater than 0, for example, x ranges from 0-100 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10). A "linker" refers to a contiguous chain of at least one atom, such as carbon, oxygen, nitrogen, sulfur, phosphorous, and combinations thereof, which connects a portion of a molecule to another portion of the same molecule or to a different molecule, moiety, or solid support (e.g., microparticle). Linkers may connect the molecule via a covalent bond or other means, such as ionic or hydrogen bond interactions. In some embodiments, the linker is a heteroatomic linker (e.g., comprising 1-10 Si, N, O, P, or S atoms), a heteroalkylene (e.g., comprising 1-10 Si, N, O, P, or S atoms and an alkylene chain) or an alkylene linker (e.g., comprising 1-12 carbon atoms). In some embodiments, a heteroalkylene linker comprises the following structure: wherein: x9and x10are each independently an integer greater than 0. In some embodiments, the heteroatomic linker is –O–, –S–, or –OP(=O)O-–O–. In some embodiments, the heteroalkylene linker comprises –OP(=O)O-–O–. In some embodiments, the heteroalkylene linker comprises at least one S-S bond. "Heteroatomic" in reference to a "heteroatomic linker" refers to a linker group consisting of one or more heteroatoms. Exemplary heteroatomic linkers include single atoms selected from the group consisting of O, N, P and S, and multiple heteroatoms for example a linker having the formula ˗P(O-)(=O)O˗ or ˗OP(O-)(=O)O˗ and multimers and combinations thereof. "Phosphate" refers to the ˗OP(=O)(Ra)Rbgroup, wherein Rais OH, O- or ORc; and Rbis OH, O-, ORc, a thiophosphate group or a further phosphate group, wherein Rc is a counter ion (e.g., Na+and the like). "Carbocyclic" refers to a stable 3- to 18-membered aromatic or non-aromatic ring comprising 3 to 18 carbon atoms. Unless stated otherwise specifically in the specification, a carbocyclic ring may be a monocyclic, bicyclic, tricyclic, or tetracyclic ring system, which may include fused or bridged ring systems, and may be partially or fully saturated. Non-aromatic carbocyclyl radicals include cycloalkyl, while aromatic carbocyclyl radicals include aryl. Unless stated otherwise specifically in the specification, a carbocyclic group is optionally substituted. "Cycloalkyl" refers to a stable non-aromatic monocyclic or polycyclic carbocyclic ring, which may include fused or bridged ring systems, having from three to fifteen carbon atoms, preferably having from three to ten carbon atoms, and which is saturated or unsaturated and attached to the rest of the molecule by a single bond. Monocyclic cycloalkyls include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Polycyclic cycloalkyls include, for example, adamantyl, norbornyl, decalinyl, 7,7-dimethyl- bicyclo-[2.2.1]heptanyl, and the like. Unless stated otherwise specifically in the specification, a cycloalkyl group is optionally substituted. "Aryl" refers to a ring system comprising at least one carbocyclic aromatic ring. In some embodiments, an aryl comprises from 6 to 18 carbon atoms. The aryl ring may be a monocyclic, bicyclic, tricyclic, or tetracyclic ring system, which may include fused or bridged ring systems. Aryls include, but are not limited to, aryls derived from aceanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, fluoranthene, fluorene, as-indacene, s-indacene, indane, indene, naphthalene, phenalene, phenanthrene, pleiadene, pyrene, and triphenylene. Unless stated otherwise specifically in the specification, an aryl group is optionally substituted. "Heterocyclic" or "heterocyclyl" refers to a stable 3- to 18-membered aromatic or non-aromatic ring comprising one to twelve carbon atoms and from one to six heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur. Unless stated otherwise specifically in the specification, the heterocyclic ring may be a monocyclic, bicyclic, tricyclic, or tetracyclic ring system, which may include fused or bridged ring systems; and the nitrogen, carbon or sulfur atoms in the heterocyclic ring may be optionally oxidized; the nitrogen atom may be optionally quaternized; and the heterocyclic ring may be partially or fully saturated. Examples of aromatic heterocyclic rings are listed below in the definition of heteroaryls (i.e., heteroaryl being a subset of heterocyclic). Examples of non-aromatic heterocyclic rings include, but are not limited to, dioxolanyl, thienyl[1,3]dithianyl, decahydroisoquinolyl, imidazolinyl, imidazolidinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, oxazolidinyl, piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl, pyrazolidinyl, pyrazolopyrimidinyl, quinuclidinyl, thiazolidinyl, tetrahydrofuryl, trioxanyl, trithianyl, triazinanyl, tetrahydropyranyl, thiomorpholinyl, thiamorpholinyl, 1-oxo-thiomorpholinyl, and 1,1-dioxo-thiomorpholinyl. Unless stated otherwise specifically in the specification, a heterocyclic group is optionally substituted. "Heteroaryl" refers to a 5- to 14-membered ring system comprising one to thirteen carbon atoms, one to six heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur, and at least one aromatic ring. For purposes of certain embodiments of this disclosure, the heteroaryl radical may be a monocyclic, bicyclic, tricyclic, or tetracyclic ring system, which may include fused or bridged ring systems; and the nitrogen, carbon, or sulfur atoms in the heteroaryl radical may be optionally oxidized; the nitrogen atom may be optionally quaternized. Examples include, but are not limited to, azepinyl, acridinyl, benzimidazolyl, benzthiazolyl, benzindolyl, benzodioxolyl, benzofuranyl, benzooxazolyl, benzothiazolyl, benzothiadiazolyl, benzo[b][1,4]dioxepinyl, 1,4-benzodioxanyl, benzonaphthofuranyl, benzoxazolyl, benzodioxolyl, benzodioxinyl, benzopyranyl, benzopyranonyl, benzofuranyl, benzofuranonyl, benzothienyl (benzothiophenyl), benzotriazolyl, benzo[4,6]imidazo[1,2-a]pyridinyl, benzoxazolinonyl, benzimidazolthionyl, carbazolyl, cinnolinyl, dibenzofuranyl, dibenzothiophenyl, furanyl, furanonyl, isothiazolyl, imidazolyl, indazolyl, indolyl, indazolyl, isoindolyl, indolinyl, isoindolinyl, isoquinolyl, indolizinyl, isoxazolyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, oxiranyl, 1-oxidopyridinyl, 1-oxidopyrimidinyl, 1- oxidopyrazinyl, 1-oxidopyridazinyl, 1-phenyl-1H-pyrrolyl, phenazinyl, phenothiazinyl, phenoxazinyl, phthalazinyl, pteridinyl, pteridinonyl, purinyl, pyrrolyl, pyrazolyl, pyridinyl, pyridinonyl, pyrazinyl, pyrimidinyl, pryrimidinonyl, pyridazinyl, pyrrolyl, pyrido[2,3- d]pyrimidinonyl, quinazolinyl, quinazolinonyl, quinoxalinyl, quinoxalinonyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, thiazolyl, thiadiazolyl, thieno[3,2-d]pyrimidin-4-onyl, thieno[2,3-d]pyrimidin-4-onyl, triazolyl, tetrazolyl, triazinyl, and thiophenyl (i.e. thienyl). Unless stated otherwise specifically in the specification, a heteroaryl group is optionally substituted. The suffix "-ene" refers to a particular structural feature (e.g., alkyl, aryl, heteroalkyl, heteroaryl) attached to the rest of the molecule through a single bond and attached to a radical group through a single bond. In other words, the suffix "-ene" refers to a linker having the structural features of the moiety to which it is attached. The points of attachment of the "-ene" chain to the rest of the molecule and to the radical group can be through one atom of or any two atoms within the chain. For example, a heteroarylene refers to a linker comprising a heteroaryl moiety as defined herein. "Fused" refers to a ring system comprising at least two rings, wherein the two rings share at least one common ring atom, for example two common ring atoms. When the fused ring is a heterocyclyl ring or a heteroaryl ring, the common ring atom(s) may be carbon or nitrogen. Fused rings include bicyclic, tricyclic, tertracyclic, and the like. The term "substituted" used herein means any of the above groups (e.g., alkyl, alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, alkoxy, alkylether, phosphoalkyl, phosphoalkylether, thiophosphoalkyl, thiophosphoalkylether, carbocyclic, cycloalkyl, aryl, heterocyclic and / or heteroaryl) wherein at least one hydrogen atom (e.g., 1, 2, 3 or all hydrogen atoms) is replaced by a bond to a non-hydrogen atoms such as, but not limited to: a halogen atom such as F, Cl, Br, and I; an oxygen atom in groups such as hydroxyl groups, alkoxy groups, and ester groups; a sulfur atom in groups such as thiol groups, thioalkyl groups, sulfone groups, sulfonyl groups, and sulfoxide groups; a nitrogen atom in groups such as amines, amides, alkylamines, dialkylamines, arylamines, alkylarylamines, diarylamines, N-oxides, imides, and enamines; a silicon atom in groups such as trialkylsilyl groups, dialkylarylsilyl groups, alkyldiarylsilyl groups, and triarylsilyl groups; and other heteroatoms in various other groups. "Substituted" also means any of the above groups in which one or more hydrogen atoms are replaced by a higher-order bond (e.g., a double- or triple-bond) to a heteroatom such as oxygen in oxo, carbonyl, carboxyl, and ester groups; and nitrogen in groups such as imines, oximes, hydrazones, and nitriles. For example, "substituted" includes any of the above groups in which one or more hydrogen atoms are replaced with ˗NRgRh, ˗NRgC(=O)Rh, ˗NRgC(=O)NRgRh, ˗NRgC(=O)ORh, ˗NRgSO2Rh, ˗OC(=O)NRgRh, ˗ORg, ˗SRg, ˗SORg, ˗SO2Rg, ˗OSO2Rg, ˗SO2ORg, =NSO2Rg, and ˗SO2NRgRh. "Substituted also means any of the above groups in which one or more hydrogen atoms are replaced with ˗C(=O)Rg, ˗C(=O)ORg, ˗C(=O)NRgRh, ˗CH2SO2Rg, ˗CH2SO2NRgRh. In the foregoing, Rgand Rhare the same or different and independently hydrogen, alkyl, alkoxy, alkylamino, thioalkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl, N-heterocyclyl, heterocyclylalkyl, heteroaryl, N-heteroaryl and / or heteroarylalkyl. "Substituted" further means any of the above groups in which one or more hydrogen atoms are replaced by a bond to an amino, cyano, hydroxyl, nitro, oxo, thioxo, halo, alkyl, alkoxy, alkylamino, thioalkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl, N-heterocyclyl, heterocyclylalkyl, heteroaryl, N- heteroaryl and / or heteroarylalkyl group. In addition, each of the foregoing substituents may also be optionally substituted with one or more of the above substituents. In some embodiments, a subscript variable, number, or range of numbers outside of parenthesis or brackets is used to denote a repeat unit (e.g., a structure or variable within the parenthesis or brackets). As appropriate, some embodiments may include repeat units where a variable, number, or range of numbers is zero for one occurrence and an integer greater than zero for another occurrence (e.g., in the case of nested parenthesis or brackets). For example, considering the following structure: wherein: X1is -CH2-CH2-; X2is -O-CH2-CH2-; n is, at each occurrence, independently 0 or 1; and m is 2, 3, or 4; When m is 2, n is 0 for the first occurrence (i.e., repeat unit of m) and 1 for the second occurrence, the following structure would result: -O-CH2-CH2-CH2-CH2-O-CH2-CH2- "Conjugate" or "bio-conjugate" and related variations refer to a chemical reaction strategy for forming a stable covalent bond between two molecules. The terms "conjugation" and "bio-conjugation" are generally used when one of the molecules is a biomolecule (e.g., an antibody), but can be used to describe forming a covalent bond with a non-biomolecule (e.g., a polymeric resin). The product or compound resulting from such a reaction strategy is a "conjugate," "bio-conjugate," or a grammatical equivalent. Embodiments of the disclosure disclosed herein are also meant to encompass all compounds being isotopically labelled by having one or more atoms replaced by an atom having a different atomic mass or mass number. Examples of isotopes that can be incorporated into the disclosed compounds include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, and iodine, such as2H,3H,11C,13C,14C,13N,15N,15O,17O,18O,31P,32P,35S,18F,36Cl,123I, and125I, respectively. Isotopically labeled compounds and polymer compounds of the present disclosure (e.g., compounds of Structure (I)) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described below and in the following Examples using an appropriate isotopically labeled reagent in place of the non-labeled reagent previously employed. "Stable compound" and "stable structure" are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. In some embodiments, the compounds of the present disclosure (e.g., compounds of Structure (I)) are limited to only stable compounds. In some embodiments, compounds of Structure (I) do not include any peroxide moieties (i.e., -O-O- ). In some embodiments, the compounds of Structure (I) do not include any diphosphate moieties. "Optional" or "optionally" means that the subsequently described event or circumstances may or may not occur, and that the description includes instances where said event or circumstance occurs and instances in which it does not. For example, "optionally substituted alkyl" means that the alkyl group may or may not be substituted and that the description includes both substituted alkyl groups and alkyl groups having no substitution. "Salt" includes both acid and base addition salts. "Acid addition salt" refers to those salts which are formed with inorganic acids such as, but not limited to, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, and organic acids such as, but not limited to, acetic acid, 2,2-dichloroacetic acid, adipic acid, alginic acid, ascorbic acid, aspartic acid, benzenesulfonic acid, benzoic acid, 4- acetamidobenzoic acid, camphoric acid, camphor-10-sulfonic acid, capric acid, caproic acid, caprylic acid, carbonic acid, cinnamic acid, citric acid, cyclamic acid, dodecylsulfuric acid, ethane-1,2-disulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, formic acid, fumaric acid, galactaric acid, gentisic acid, glucoheptonic acid, gluconic acid, glucuronic acid, glutamic acid, glutaric acid, 2-oxo-glutaric acid, glycerophosphoric acid, glycolic acid, hippuric acid, isobutyric acid, lactic acid, lactobionic acid, lauric acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid, mucic acid, naphthalene-1,5-disulfonic acid, naphthalene-2-sulfonic acid, 1-hydroxy-2-naphthoic acid, nicotinic acid, oleic acid, orotic acid, oxalic acid, palmitic acid, pamoic acid, propionic acid, pyroglutamic acid, pyruvic acid, salicylic acid, 4-aminosalicylic acid, sebacic acid, stearic acid, succinic acid, tartaric acid, thiocyanic acid, p-toluenesulfonic acid, trifluoroacetic acid, undecylenic acid, and the like. "Base addition salt" refers to those salts which are prepared from addition of an inorganic base or an organic base to the free acid. Salts derived from inorganic bases include, but are not limited to, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Salts derived from organic bases include, but are not limited to, salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as ammonia, isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, diethanolamine, ethanolamine, deanol, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, benethamine, benzathine, ethylenediamine, glucosamine, methylglucamine, theobromine, triethanolamine, tromethamine, purines, piperazine, piperidine, N-ethylpiperidine, polyamine resins and the like. Particularly preferred organic bases are isopropylamine, diethylamine, ethanolamine, trimethylamine, dicyclohexylamine, choline and caffeine. Crystallizations may produce a solvate of the compounds described herein. Embodiments of the present disclosure include all solvates of the described compounds. As used herein, the term "solvate" refers to an aggregate that comprises one or more molecules of a compound of the disclosure with one or more molecules of solvent. The solvent may be water, in which case the solvate may be a hydrate. Alternatively, the solvent may be an organic solvent. Thus, the compounds of the present disclosure may exist as a hydrate, including a monohydrate, dihydrate, hemihydrate, sesquihydrate, trihydrate, tetrahydrate and the like, as well as the corresponding solvated forms. The compounds of the disclosure may be true solvates, while in other cases the compounds of the disclosure may merely retain adventitious water or another solvent or be a mixture of water plus some adventitious solvent. Embodiments of the compounds of the disclosure (e.g., compounds of structure I), or their salts, tautomers or solvates may contain one or more stereocenters and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that may be defined, in terms of absolute stereochemistry, as (R)- or (S)- or, as (D)- or (L)- for amino acids. Embodiments of the present disclosure are meant to include all such possible isomers, as well as their racemic and optically pure forms. Optically active (+) and (-), (R)- and (S)-, or (D)- and (L)- isomers may be prepared using chiral synthons or chiral reagents, or resolved using conventional techniques, for example, chromatography and fractional crystallization. Conventional techniques for the preparation / isolation of individual enantiomers include chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high pressure liquid chromatography (HPLC). When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended that the compounds include both E and Z geometric isomers. Likewise, all tautomeric forms are also intended to be included. A "stereoisomer" refers to a compound made up of the same atoms bonded by the same bonds but having different three-dimensional structures, which are not interchangeable. The present disclosure contemplates various stereoisomers and mixtures thereof and includes "enantiomers," which refers to two stereoisomers whose molecules are non-superimposable mirror images of one another. A "tautomer" refers to a proton shift from one atom of a molecule to another atom of the same molecule. The present disclosure includes tautomers of any said compounds. Various tautomeric forms of the compounds are easily derivable by those of ordinary skill in the art. The chemical naming protocol and structure diagrams used herein are a modified form of the I.U.P.A.C. nomenclature system, using the ACD / Name Version 9.07 software program and / or ChemDraw Ultra Version 11.0 software naming program (CambridgeSoft). Common names familiar to one of ordinary skill in the art are also used. Compounds As noted above, in one embodiment of the present disclosure, a water-soluble polymeric compound useful as covalent linker between antibodies and payloads is provided. Accordingly, one embodiment provides a compound having the following Structure (I): or a salt, stereoisomer, or tautomer thereof, wherein: R1has one of the following structures: A is an antibody; R2has the following structure: L1at each occurrence, independently has one of the following structures: L2at each occurrence, independently has one of the following structures: L3at each occurrence, independently has one of the following structures: R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, an cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor; L4at each occurrence, independently one the following structure: v is an integer ranging from 1-30; n is, at each occurrence, independently an integer ranging from 0 to 12; m is, at each occurrence, independently an integer ranging from 0 to 12; p is, at each occurrence, independently an integer ranging from 1 to 30; and w is an integer ranging from 0 to 12. In some embodiments, R1has one of the following structures: In certain embodiments, R1has the following structure: . In some embodiments, R1has the following structure: . In certain embodiments, R1has the following structure: . In some embodiments, R1has the following structure: . In certain embodiments, at least one occurrence of L1has one of the following structures: , , , , , , , , or . In some embodiments, at least one occurrence of L1has one of the following structures: , , , , , , or . In certain embodiments, each occurrence of L1has one of the following structures: , , , , , , , , or . In some embodiments, each occurrence of L1has one of the following structures: In certain embodiments, each occurrence of L1has the following structure: . In some embodiments, each occurrence of L1has the following structure: . In certain embodiments, each occurrence of L1has the following structure: . In some embodiments, each occurrence of L1has the following structure: . In certain embodiments, each occurrence of L1has the following structure: . In some embodiments, each occurrence of L1has the following structure: . In certain embodiments, each occurrence of L1has the following structure: . In some embodiments, at least one occurrence of L2has one of the following structures: In certain embodiments, at least one occurrence of L2has one of the following structures: In some embodiments, each occurrence of L2has one of the following structures: In certain embodiments, each occurrence of L2has one of the following structures: , , . In some embodiments, each occurrence of L2the following structure: . In certain embodiments, each occurrence of L2the following structure: . In some embodiments, each occurrence of L2the following structure: . In certain embodiments, each occurrence of L2the following structure: . In some embodiments, at least one occurrence of L3has one of the following structures:

[0002] wherein: R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, a cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor. In certain embodiments, each occurrence of L3has one of the following structures:

[0003] wherein: R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, an cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor. In some embodiments, at least one occurrence of D has one of the following structures:

[0004] In certain embodiments, at least one occurrence of L3has one of the following structures: wherein: L' has the following structure: MMAE has the following structure: . In certain embodiments, each occurrence of L3has one of the following structures: wherein: L' has the following structure: MMAE has the following structure: In some embodiments, at least one occurrence of L4has one of the following structures: In certain embodiments, each occurrence of L4has one of the following structures: In some embodiments, each occurrence of L4has the following structure: . In certain embodiments, n is 0, 1, 2, or 3. In some embodiments, n is 4, 5, 6, 7, 8, 9, 10, 11, or 12. In some embodiments, n is 0. In certain embodiments, n is 1. In some embodiments, n is 2 or 3. In some embodiments, n is 0, 1, 2, or 3 and m is 1, 2, 3, 4, or 5. In some embodiments, n is 0, 1, 2, or 3, m is 1, 2, 3, 4, or 5, p is 1-10, w is 0-3, and v is 1-10. In some embodiments, m is 1, 2, 3, 4, or 5. In some embodiments, m is 6, 7, 8, 9, 10, 11, or 12. In certain embodiments, m is 0. In certain embodiments, p is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, p is 11- 30. In some embodiments, w is 0, 1, 2, or 3. In certain embodiments, w is 4, 5, 6, 7, 8, 9, 10, 11, or 12. In some embodiments, v is 1, 2, 3, 4, 5, 6, 7, or 8. In some embodiments, v is 9-15. In certain embodiments, v is 16-20. In some embodiments, v is 21-25. In certain embodiments, v is 26-30. In some embodiments, v is 2 and p is 0 for the first occurrence and greater than 0 for the second occurrence. In some embodiments, v is 2, 3, 4, or 4 and p is 0 for the first occurrence and 1, 2, 3, or 4 for each occurrence after the first occurrence. In certain embodiments, the compound has one of the following formulae: C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-HEG-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2dU])5-HEG-dT, C6SS-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, HS-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, or Mal-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT wherein: Mal has the following structure: HS has the following structure: C6SS has the following structure: TEG has the following structure: HEG has the following structure: PEG1K has the following structure: [C6-NH2]dU has the following structure: [dU-C6-NH-MMAE] has the following structure: wherein: L' has the following structure: MMAE has the following structure: dT has the following structure: C6 has the following structure: C4 has the following structure: C3 has the following structure: C2 has the following structure: TEG, HEG, PEG1K, [C6-NH2]dU, [dU-C6-NH-MMAE], C6, C4, C3, and C2 are connected from left to right in the shown orientations. In some embodiments, the compound has one of the following formulae: C6SS-Y-([C6-NH2]dU)3-HEG-dT, C6SS-Y-([C6-NH2]dU)5-HEG-dT, C6SS-Y-([C6-NH2]dU)7-HEG-dT, or C6SS-Y-([C6-NH2]dU)10-HEG-dT, wherein: Y is a direct bond, C6, C4, C3, C2, TEG, PEG1K, HEG, (HEG)2, or (HEG)3; [C6-NH2]dU has the following structure: C6SS has the following structure: TEG has the following structure: HEG has the following structure: PEG1K has the following structure: C6 has the following structure: C4 has the following structure: C3 has the following structure: C2 has the following structure: dT has the following structure: TEG, HEG, PEG1K, [C6-NH2]dU, C6, C4, C3, and C2 are connected from left to right in the shown orientations. In certain embodiments, the compound has one of the following formulae: C6SS-HEG-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-TEG-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C6-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C4-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C3-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C2-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, or C6SS-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, wherein: X is an integer ranging from 1 to 6; C6SS has the following structure: TEG has the following structure: HEG has the following structure: PEG1K has the following structure: [C6-NH2]dU has the following structure: C6 has the following structure: C4 has the following structure: C3 has the following structure: C2 has the following structure: dT has the following structure: TEG, HEG, PEG1K, [C6-NH2]dU, C6, C4, C3, and C2 are connected from left to right in the shown orientations. In certain embodiments, the compound has one of the following formulae: Mal-HEG-(HEG-HEG-HEG-[dU-C6-NH-MMAE])5-HEG-dT, Mal-HEG-HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG- dT, Mal -HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -TEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -C6-[dU-C6-NH-MMAE] -(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])3-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])7-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])10-HEG-dT, wherein: Mal has the following structure: TEG has the following structure: HEG has the following structure: C6 has the following structure: [dU-C6-NH-MMAE] has the following structure: wherein: L' has the following structure: MMAE has the following structure: dT has the following structure: TEG, HEG, PEG1K, [dU-C6-NH-MMAE], and C6 are connected from left to right in the shown orientations. It is noted that each structural pieces of the compounds disclosed in the present disclosure (i.e., C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-HEG-HEG- [C6-NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG- (HEG-HEG-HEG-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-HEG-HEG-[C6-NH2]dU-(HEG-HEG- HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6- NH2]dU)4-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6- NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-HEG-HEG- [C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU- (HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-HEG-[C6- NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-[C6- NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(HEG-[C6- NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K- [C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4- HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU- (HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS- C2-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-[C6-NH2]dU)4- HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG- [C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG- [C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS- C6-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG- [C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS- C2-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-[C6- NH2]dU)4-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(PEG1K-[C6- NH2]dU)5-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(PEG1K-[C6- NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS- PEG1K-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(PEG1K- [C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C4- [C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(PEG1K-[C6- NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-[C6- NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2dU])5-HEG-dT, C6SS- HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, HS-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, Mal-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, C6SS-HEG-[C6-NH2]dU-((HEG)X[C6- NH2]dU)3-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-TEG- [C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C6-[C6-NH2]dU-((HEG)X[C6- NH2]dU)3-HEG-dT, C6SS-C4-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C3-[C6- NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C2-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3- HEG-dT, C6SS-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, Mal-HEG-(HEG-HEG-HEG- [dU-C6-NH-MMAE])5-HEG-dT, Mal-HEG-HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU- C6-NH-MMAE])4-HEG-dT, Mal -HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH- MMAE])4-HEG-dT, Mal -TEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4- HEG-dT, Mal -C6-[dU-C6-NH-MMAE] -(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])3-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])5- HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])7-HEG-dT, and Mal -HEG-(HEG-[dU-C6- NH-MMAE])10-HEG-dT) are connected from left to right in the shown orientations of each structural pieces. For example, Mal-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT has Mal structure connected to an oxygen of a first HEG in the shown orientation . The polyethylene glycol portion of the first HEG is further connected to an oxygen of a second HEG in the shown orientation . Next, the polyethylene glycol portion of the second HEG is connected to an oxygen of [dU-C6-NH- The structure of (HEG-[dU-C6-NH-MMAE]) repeats 5 times. Then, the tetrahydrofuran connection of a fifth [dU-C6-NH-MMAE] is connected to an oxygen of HEG in the shown orientation . Finally, the polyethylene glycol portion of the HEG is connected to the dT in the shown orientation . In some embodiments, a representative compound Mal-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT of Structure (I) is included in FIG.1. In some embodiments, the antibody (A) is trastuzumab, gemtuzumab, brentuximab, vorsetuzumab, lorvotuzumab, cantuzumab, bivatuzumabor inotuzumab, or vadastuximab. For ease of illustration, various compounds comprising phosphorous moieties (e.g., phosphate and the like) are depicted in the anionic state (e.g., -O-PO-(OH)-O-, -OPO32-). One of skill in the art will readily understand that the charge is dependent on pH and the uncharged (e.g., protonated or salt, such as sodium or other cation) forms are also included in the scope of embodiments of the disclosure. In some embodiments, D is at each occurrence, independently an NSAID, a kinase inhibitor, an anthracycline, an EGFR inhibitor, or an alkylating agent. In some embodiments, the D is an anti-cancer drug. In certain specific embodiments, D is at each occurrence, independently an anti-cancer drug, and the antibody specific for a tumor cell antigen. Anti-cancer drug, as used herein, includes derivatives (e.g., compounds with added linkers covalently binding the drug to the compounds of Structure (I)). For example, maytansine is a cancer drug and maytansinoids are cancer drug derivatives. In certain embodiments, the anti-cancer drug is an epidermal growth factor receptor (EGFR) inhibitor, phosphatidylinositol kinase (PI3K) inhibitor, insulin-like growth factor receptor (IGF1R) inhibitor, Janus kinase (JAK) inhibitor, a Met kinase inhibitor, a SRC family kinase inhibitor, a mitogen-activated protein kinase (MEK) inhibitor, an extracellular-signal- regulated kinase (ERK) inhibitor, a topoisomerase inhibitors (such as irinotecan, or such as etoposide, or such asdoxorubicin), taxanes (such as anti-microtubule agents including paclitaxel and docetaxel), anti-metabolite agents (such as 5-FU or such as gemcitabine), alkylating agents (such as cisplatin or such as cyclophosphamide), or a taxane. Anti-cancer drugs that can be modified and incorporated into embodiments of compounds of the present disclosure include, for example, auristatin F; auristatin E; maytansine; calicheamicin; paclitaxel; doxorubicin; cryptophycin; erlotinib; CC-1065; carzelesin; SJG-136; DSB-120; afatinib; Iressa or methotrexate. Other non-limiting examples of anti-cancer drugs include Gleevec® (Imatinib Mesylate), Velcade® (bortezomib), Casodex (bicalutamide), Iressa® (gefitinib), and Adriamycin, alkylating agents such as thiotepa and cyclosphosphamide (CYTOXAN®); alkyl sulfonates such as busulfan, improsulfan and piposulfan; aziridines such as benzodopa, carboquone, meturedopa, and uredopa; ethylenimines and methylamelamines including altretamine, triethylenemelamine, triethylenephosphoramide, triethylenethiophosphaoramide and trimethylolomelamine; nitrogen mustards such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, ranimustine; antibiotics such as aclacinomysins, actinomycin, authramycin, azaserine, bleomycins, cactinomycin, calicheamicin, carabicin, carminomycin, carzinophilin, Casodex®, chromomycins, dactinomycin, daunorubicin, detorubicin, 6-diazo-5- oxo-L-norleucine, doxorubicin, epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins, mycophenolic acid, nogalamycin, olivomycins, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate and 5-fluorouracil (5-FU); folic acid analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogs such as fludarabine, 6- mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6- azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocitabine, floxuridine, androgens such as calusterone, dromostanolone propionate, epitiostanol, mepitiostane, testolactone; anti-adrenals such as aminoglutethimide, mitotane, trilostane; folic acid replenisher such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine; diaziquone; elfomithine; elliptinium acetate; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidamine; mitoguazone; mitoxantrone; mopidamol; nitracrine; pentostatin; phenamet; pirarubicin; podophyllinic acid; 2- ethylhydrazide; procarbazine; PSK.RTM.; razoxane; sizofiran; spirogermanium; tenuazonic acid; triaziquone; 2,2',2''-trichlorotriethylamine; urethan; vindesine; dacarbazine; mannomustine; mitobronitol; mitolactol; pipobroman; gacytosine; arabinoside (“Ara-C”); cyclophosphamide; thiotepa; taxanes, e.g. paclitaxel (TAXOLTM, Bristol-Myers Squibb Oncology, Princeton, N.J.) and docetaxel (TAXOTERETM, Rhone-Poulenc Rorer, Antony, France); retinoic acid; esperamicins or capecitabine. Also included as suitable cancer drugs are anti-hormonal agents that act to regulate or inhibit hormone action on tumors such as anti-estrogens including for example tamoxifen, (NolvadexTM), raloxifene, aromatase inhibiting 4(5)-imidazoles, 4- hydroxytamoxifen, trioxifene, keoxifene, LY 117018, onapristone, and toremifene (Fareston); and anti-androgens such as flutamide, nilutamide, bicalutamide, leuprolide, and goserelin; chlorambucil; gemcitabine; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin and carboplatin; vinblastine; platinum; etoposide (VP-16); ifosfamide; mitomycin C; mitoxantrone; vincristine; vinorelbine; navelbine; novantrone; teniposide; daunomycin; aminopterin; xeloda; ibandronate; camptothecin-11 (CPT-11); topoisomeRASe inhibitor RFS 2000; difluoromethylornithine (DMFO). Pharmaceutical Compositions One embodiment provides a composition comprising the compound of Structure (I) and a pharmaceutically acceptable carrier. One embodiment provides a pharmaceutical composition comprising the compound of Structure (I), or a stereoisomer, tautomer, or salt thereof and a pharmaceutically acceptable excipient. Some embodiments are directed to pharmaceutical compositions. The pharmaceutical composition comprises one (or more) compounds of Structure (I) and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical composition is formulated for oral administration. In other embodiments, the pharmaceutical composition is formulated for injection. In still more embodiments, the pharmaceutical compositions comprise a compound of Structure (I) and an additional therapeutic agent (e.g., anticancer agent). Non-limiting examples of such therapeutic agents are described herein below. Suitable routes of administration include, but are not limited to, oral, intravenous, rectal, aerosol, parenteral, ophthalmic, pulmonary, transmucosal, transdermal, vaginal, otic, nasal, and topical administration. In addition, by way of example only, parenteral delivery includes intramuscular, subcutaneous, intravenous, intramedullary injections, as well as intrathecal, direct intraventricular, intraperitoneal, intralymphatic, and intranasal injections. In certain embodiments, a compound of Structure (I) is administered in a local rather than systemic manner, for example, via injection of the compound directly into an organ, often in a depot preparation or sustained release formulation. In specific embodiments, long-acting formulations are administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Furthermore, in other embodiments, the drug is delivered in a targeted drug delivery system, for example, in a liposome coated with organ-specific antibody. In such embodiments, the liposomes are targeted to and taken up selectively by the organ. In yet other embodiments, a compound of Structure (I) is provided in the form of a rapid release formulation, in the form of an extended-release formulation, or in the form of an intermediate release formulation. In yet other embodiments, the compound of Structure (I) is administered topically. The compounds of Structure (I) are effective over a wide dosage range. For example, in the treatment of adult humans, dosages from 0.01 to 1000 mg, from 0.5 to 100 mg, from 1 to 50 mg per day, and from 5 to 40 mg per day are examples of dosages that are used in some embodiments. An exemplary dosage is 10 to 30 mg per day. The exact dosage will depend upon the route of administration, the form in which the compound is administered, the subject to be treated, the body weight of the subject to be treated, and the preference and experience of the attending physician. In some embodiments, a compound of Structure (I) is administered in a single dose. Typically, such administration will be by injection, e.g., intravenous injection, in order to introduce the agent quickly. However, other routes are used as appropriate. A single dose of a compound of Structure (I) may also be used for treatment of an acute condition. In some embodiments, a compound of Structure (I) is administered in multiple doses. In some embodiments, dosing is about once, twice, three times, four times, five times, six times, or more than six times per day. In other embodiments, dosing is about once a month, once every two weeks, once a week, or once every other day. In another embodiment a compound of Structure (I) and another agent are administered together about once per day to about 6 times per day. In another embodiment the administration of a compound of Structure (I) and an agent continues for less than about 7 days. In yet another embodiment the administration continues for more than about 6, 10, 14, 28 days, two months, six months, or one year. In some cases, continuous dosing is achieved and maintained as long as necessary. Administration of the compound of Structure (I) may continue as long as necessary. In some embodiments, a compound of Structure (I) is administered for more than 1, 2, 3, 4, 5, 6, 7, 14, or 28 days. In some embodiments, a compound of Structure (I) is administered for less than 28, 14, 7, 6, 5, 4, 3, 2, or 1 day. In some embodiments, a compound of Structure (I) is administered chronically on an ongoing basis, e.g., for the treatment of chronic effects. In some embodiments, the compound of Structure (I) is administered in dosages. It is known in the art that due to inter-subject variability in compound pharmacokinetics, individualization of dosing regimen is necessary for optimal therapy. Dosing for a compound of the disclosure may be found by routine experimentation considering the instant disclosure. In some embodiments, the compound of Structure (I) is formulated into pharmaceutical compositions. In specific embodiments, pharmaceutical compositions are formulated in a conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. Any pharmaceutically acceptable techniques, carriers, and excipients are used as suitable to formulate the pharmaceutical compositions described herein: Remington: The Science and Practice of Pharmacy, Nineteenth Ed (Easton, Pa.: Mack Publishing Company, 1995); Hoover, John E., Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pennsylvania 1975; Liberman, H.A. and Lachman, L., Eds., Pharmaceutical Dosage Forms, Marcel Decker, New York, N.Y., 1980; and Pharmaceutical Dosage Forms and Drug Delivery Systems, Seventh Ed. (Lippincott Williams & Wilkins1999). Provided herein are pharmaceutical compositions comprising a compound of Structure (I) and a pharmaceutically acceptable diluent(s), excipient(s), or carrier(s). In certain embodiments, the compounds described are administered as pharmaceutical compositions in which a compound of Structure (I) are mixed with other active ingredients, as in combination therapy. Encompassed herein are all combinations of actives set forth in the combination therapies section below and throughout this disclosure. In specific embodiments, the pharmaceutical compositions include one or more compound of Structure (I). A pharmaceutical composition, as used herein, refers to a mixture of a compound of Structure (I) with other chemical components, such as carriers, stabilizers, diluents, dispersing agents, suspending agents, thickening agents, and / or excipients. In certain embodiments, the pharmaceutical composition facilitates administration of the compound to an organism. In some embodiments, practicing the methods of treatment or use provided herein, therapeutically effective amounts of a compound of Structure (I) provided herein are administered in a pharmaceutical composition to a mammal having a disease, disorder, or medical condition to be treated. In specific embodiments, the mammal is a human. In certain embodiments, therapeutically effective amounts vary depending on the severity of the disease, the age and relative health of the subject, the potency of the compound used and other factors. The polymer compound of the compound of Structure (I) is used singly or in combination with one or more therapeutic agents as components of mixtures. In one embodiment, one or more compound of Structure (I) is formulated in an aqueous solution. In specific embodiments, the aqueous solution is selected from, by way of example only, a physiologically compatible buffer, such as Hank's solution, Ringer's solution, or physiological saline buffer. In other embodiments, one or more compound of Structure (I) is / are formulated for transmucosal administration. In specific embodiments, transmucosal formulations include penetrants that are appropriate to the barrier to be permeated. In still other embodiments wherein the compounds described herein are formulated for other parenteral injections, appropriate formulations include aqueous or non-aqueous solutions. In specific embodiments, such solutions include physiologically compatible buffers and / or excipients. In other embodiments, therapeutically effective amounts of at least one of the compounds described herein are formulated for buccal or sublingual administration. Formulations suitable for buccal or sublingual administration include, by way of example only, tablets, lozenges, or gels. In still other embodiments, the compounds described herein are formulated for parental injection, including formulations suitable for bolus injection or continuous infusion. In specific embodiments, formulations for injection are presented in unit dosage form (e.g., in ampoules) or in multi-dose containers. Preservatives are, optionally, added to the injection formulations. In still other embodiments, the pharmaceutical compositions are formulated in a form suitable for parenteral injection as sterile suspensions, solutions, or emulsions in oily or aqueous vehicles. Parenteral injection formulations optionally contain formulatory agents such as suspending, stabilizing and / or dispersing agents. In specific embodiments, pharmaceutical formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form. In additional embodiments, suspensions of the active compounds (e.g., compounds of Structure (I)) are prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles for use in the pharmaceutical compositions described herein include, by way of example only, fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. In certain specific embodiments, aqueous injection suspensions contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension contains suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions. Alternatively, in other embodiments, the active ingredient is in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. In still other embodiments, the compound of Structure (I) is administered topically. The compounds described herein are formulated into a variety of topically administrable compositions, such as solutions, suspensions, lotions, gels, pastes, medicated sticks, balms, creams, or ointments. Such pharmaceutical compositions optionally contain solubilizers, stabilizers, tonicity enhancing agents, buffers, and preservatives. In yet other embodiments, the compound of Structure (I) is formulated for transdermal administration. In specific embodiments, transdermal formulations employ transdermal delivery devices and transdermal delivery patches and can be lipophilic emulsions or buffered, aqueous solutions, dissolved and / or dispersed in a polymer or an adhesive. In various embodiments, such patches are constructed for continuous, pulsatile, or on demand delivery of pharmaceutical agents. In additional embodiments, the transdermal delivery of the compound of Structure (I) is accomplished by means of iontophoretic patches and the like. In certain embodiments, transdermal patches provide controlled delivery of the compound of Structure (I). In specific embodiments, the rate of absorption is slowed by using rate-controlling membranes or by trapping the compound within a polymer matrix or gel. In alternative embodiments, absorption enhancers are used to increase absorption. Absorption enhancers or carriers include absorbable pharmaceutically acceptable solvents that assist passage through the skin. For example, in one embodiment, transdermal devices are in the form of a bandage comprising a backing member, a reservoir containing the compound optionally with carriers, optionally a rate controlling barrier to deliver the compound to the skin of the host at a controlled and predetermined rate over a prolonged period and means to secure the device to the skin. In other embodiments, the compound of Structure (I) is formulated for administration by inhalation. Various forms suitable for administration by inhalation include, but are not limited to, aerosols, mists, or powders. Pharmaceutical compositions comprising a compound of Structure (I) are conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant (e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas). In specific embodiments, the dosage unit of a pressurized aerosol is determined by providing a valve to deliver a metered amount. In certain embodiments, capsules, and cartridges of, such as, by way of example only, gelatin for use in an inhaler or insufflator is formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch. In still other embodiments, the compound of Structure (I) is formulated in rectal compositions such as enemas, rectal gels, rectal foams, rectal aerosols, suppositories, jelly suppositories, or retention enemas, containing conventional suppository bases such as cocoa butter or other glycerides, as well as synthetic polymers such as polyvinylpyrrolidone, PEG, and the like. In suppository forms of the compositions, a low-melting wax such as, but not limited to, a mixture of fatty acid glycerides, optionally in combination with melted cocoa butter. In certain embodiments, pharmaceutical compositions are formulated in any conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. Any pharmaceutically acceptable techniques, carriers, and excipients are optionally used as suitable. Pharmaceutical compositions comprising a compound of Structure (I) are manufactured in a conventional manner, such as, by way of example only, by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or compression processes. Pharmaceutical compositions include at least one pharmaceutically acceptable carrier, diluent, or excipient and at least one compound of Structure (I), described herein as an active ingredient. The active ingredient is in free-acid or free-base form, or in a pharmaceutically acceptable salt form. In addition, the methods and pharmaceutical compositions described herein include the use of N-oxides, crystalline forms (also known as polymorphs), as well as active metabolites of these compounds having the same type of activity. All tautomers of the compounds described herein are included within the scope of the compounds presented herein. Additionally, the compounds described herein encompass unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like. The solvated forms of the compounds presented herein are also considered to be disclosed herein. In addition, the pharmaceutical compositions optionally include other medicinal or pharmaceutical agents, carriers, adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure, buffers, and / or other therapeutically valuable substances. Methods for the preparation of compositions comprising the compounds described herein include formulating the compounds with one or more inert, pharmaceutically acceptable excipients or carriers to form a solid, semi-solid or liquid. Solid compositions include, but are not limited to, powders, tablets, dispersible granules, capsules, cachets, and suppositories. Liquid compositions include solutions in which a compound is dissolved, emulsions comprising a compound, or a solution containing liposomes, micelles, or nanoparticles comprising a compound as disclosed herein. Semi-solid compositions include, but are not limited to, gels, suspensions, and creams. The form of the pharmaceutical compositions described herein include liquid solutions or suspensions, solid forms suitable for solution or suspension in a liquid prior to use, or as emulsions. These compositions also optionally contain minor amounts of nontoxic, auxiliary substances, such as wetting or emulsifying agents, pH buffering agents, and so forth. In some embodiments, pharmaceutical composition comprising at least one compound of Structure (I) illustratively takes the form of a liquid where the agents are present in solution, in suspension or both. Typically, when the composition is administered as a solution or suspension a first portion of the agent is present in solution and a second portion of the agent is present in particulate form, in suspension in a liquid matrix. In some embodiments, a liquid composition includes a gel formulation. In other embodiments, the liquid composition is aqueous. In certain embodiments, useful aqueous suspensions contain one or more polymers as suspending agents. Useful polymers include water-soluble polymers such as cellulosic polymers, e.g., hydroxypropyl methylcellulose, and water-insoluble polymers such as cross-linked carboxyl-containing polymers. Certain pharmaceutical compositions described herein comprise a mucoadhesive polymer, selected for example from carboxymethylcellulose, carbomer (acrylic acid polymer), poly(methylmethacrylate), polyacrylamide, polycarbophil, acrylic acid / butyl acrylate copolymer, sodium alginate and dextran. Useful pharmaceutical compositions also, optionally, include solubilizing agents to aid in the solubility of a compound of Structure (I). The term "solubilizing agent" generally includes agents that result in formation of a micellar solution or a true solution of the agent. Certain acceptable nonionic surfactants, for example polysorbate 80, are useful as solubilizing agents, as can ophthalmically acceptable glycols, polyglycols, e.g., polyethylene glycol 400, and glycol ethers. Furthermore, useful pharmaceutical compositions optionally include one or more pH adjusting agents or buffering agents, including acids such as acetic, boric, citric, lactic, phosphoric, and hydrochloric acids; bases such as sodium hydroxide, sodium phosphate, sodium borate, sodium citrate, sodium acetate, sodium lactate and tris-hydroxymethylaminomethane; and buffers such as citrate / dextrose, sodium bicarbonate and ammonium chloride. Such acids, bases and buffers are included in an amount required to maintain pH of the composition in an acceptable range. Additionally, useful compositions also, optionally, include one or more salts in an amount required to bring osmolality of the composition into an acceptable range. Such salts include those having sodium, potassium or ammonium cations and chloride, citrate, ascorbate, borate, phosphate, bicarbonate, sulfate, thiosulfate, or bisulfite anions; suitable salts include sodium chloride, potassium chloride, sodium thiosulfate, sodium bisulfite and ammonium sulfate. Other useful pharmaceutical compositions optionally include one or more preservatives to inhibit microbial activity. Suitable preservatives include mercury-containing substances such as merfen and thiomersal; stabilized chlorine dioxide; and quaternary ammonium compounds such as benzalkonium chloride, cetyltrimethylammonium bromide and cetylpyridinium chloride. Still other useful compositions include one or more surfactants to enhance physical stability or for other purposes. Suitable nonionic surfactants include polyoxyethylene fatty acid glycerides and vegetable oils, e.g., polyoxyethylene (60) hydrogenated castor oil; and polyoxyethylene alkylethers and alkylphenyl ethers, e.g., octoxynol 10, octoxynol 40. Still other useful compositions include one or more antioxidants to enhance chemical stability where required. Suitable antioxidants include, by way of example only, ascorbic acid and sodium metabisulfite. In certain embodiments, aqueous suspension compositions are packaged in single-dose non-reclosable containers. Alternatively, multiple-dose reclosable containers are used, in which case it is typical to include a preservative in the composition. In alternative embodiments, other delivery systems for hydrophobic pharmaceutical compounds are employed. Liposomes and emulsions are examples of delivery vehicles or carriers useful herein. In certain embodiments, organic solvents such as N-methylpyrrolidone are also employed. In additional embodiments, the compounds described herein are delivered using a sustained-release system, such as semipermeable matrices of solid hydrophobic polymers containing the therapeutic agent. Various sustained-release materials are useful herein. In some embodiments, sustained-release capsules release the compounds for a few weeks up to over 100 days. Depending on the chemical nature and the biological stability of the therapeutic reagent, additional strategies for protein stabilization are employed. In certain embodiments, the formulations described herein comprise one or more antioxidants, metal chelating agents, thiol containing compounds and / or other general stabilizing agents. Examples of such stabilizing agents, include, but are not limited to: (a) about 0.5% to about 2% w / v glycerol, (b) about 0.1% to about 1% w / v methionine, (c) about 0.1% to about 2% w / v monothioglycerol, (d) about 1 mM to about 10 mM EDTA, (e) about 0.01% to about 2% w / v ascorbic acid, (f) 0.003% to about 0.02% w / v polysorbate 80, (g) 0.001% to about 0.05% w / v. polysorbate 20, (h) arginine, (i) heparin, (j) dextran sulfate, (k) cyclodextrins, (l) pentosan polysulfate and other heparinoids, (m) divalent cations such as magnesium and zinc; or (n) combinations thereof. In some embodiments, the concentration of one or more compounds provided in the pharmaceutical compositions is less than 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 19%, 18%, 17%, 16%, 15%,14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.009%, 0.008%, 0.007%, 0.006%, 0.005%, 0.004%, 0.003%, 0.002%, 0.001%, 0.0009%, 0.0008%, 0.0007%, 0.0006%, 0.0005%, 0.0004%, 0.0003%, 0.0002%, or 0.0001% w / w, w / v or v / v. In some embodiments, the concentration of one or more compounds is greater than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 19.75%, 19.50%, 19.25% 19%, 18.75%, 18.50%, 18.25% 18%, 17.75%, 17.50%, 17.25% 17%, 16.75%, 16.50%, 16.25% 16%, 15.75%, 15.50%, 15.25% 15%, 14.75%, 14.50%, 14.25% 14%, 13.75%, 13.50%, 13.25% 13%, 12.75%, 12.50%, 12.25% 12%, 11.75%, 11.50%, 11.25% 11%, 10.75%, 10.50%, 10.25% 10%, 9.75%, 9.50%, 9.25% 9%, 8.75%, 8.50%, 8.25% 8%, 7.75%, 7.50%, 7.25% 7%, 6.75%, 6.50%, 6.25% 6%, 5.75%, 5.50%, 5.25% 5%, 4.75%, 4.50%, 4.25%, 4%, 3.75%, 3.50%, 3.25%, 3%, 2.75%, 2.50%, 2.25%, 2%, 1.75%, 1.50%, 125% , 1%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.009%, 0.008%, 0.007%, 0.006%, 0.005%, 0.004%, 0.003%, 0.002%, 0.001%, 0.0009%, 0.0008%, 0.0007%, 0.0006%, 0.0005%, 0.0004%, 0.0003%, 0.0002%, or 0.0001% w / w, w / v, or v / v. In some embodiments, the concentration of one or more compounds is in the range from approximately 0.0001% to approximately 50%, approximately 0.001% to approximately 40 %, approximately 0.01% to approximately 30%, approximately 0.02% to approximately 29%, approximately 0.03% to approximately 28%, approximately 0.04% to approximately 27%, approximately 0.05% to approximately 26%, approximately 0.06% to approximately 25%, approximately 0.07% to approximately 24%, approximately 0.08% to approximately 23%, approximately 0.09% to approximately 22%, approximately 0.1% to approximately 21%, approximately 0.2% to approximately 20%, approximately 0.3% to approximately 19%, approximately 0.4% to approximately 18%, approximately 0.5% to approximately 17%, approximately 0.6% to approximately 16%, approximately 0.7% to approximately 15%, approximately 0.8% to approximately 14%, approximately 0.9% to approximately 12%, approximately 1% to approximately 10% w / w, w / v or v / v. In some embodiments, the concentration of one or more compounds is in the range from approximately 0.001% to approximately 10%, approximately 0.01% to approximately 5%, approximately 0.02% to approximately 4.5%, approximately 0.03% to approximately 4%, approximately 0.04% to approximately 3.5%, approximately 0.05% to approximately 3%, approximately 0.06% to approximately 2.5%, approximately 0.07% to approximately 2%, approximately 0.08% to approximately 1.5%, approximately 0.09% to approximately 1%, approximately 0.1% to approximately 0.9% w / w, w / v or v / v. In some embodiments, the amount of one or more compounds is equal to or less than 10 g, 9.5 g, 9.0 g, 8.5 g, 8.0 g, 7.5 g, 7.0 g, 6.5 g, 6.0 g, 5.5 g, 5.0 g, 4.5 g, 4.0 g, 3.5 g, 3.0 g, 2.5 g, 2.0 g, 1.5 g, 1.0 g, 0.95 g, 0.9 g, 0.85 g, 0.8 g, 0.75 g, 0.7 g, 0.65 g, 0.6 g, 0.55 g, 0.5 g, 0.45 g, 0.4 g, 0.35 g, 0.3 g, 0.25 g, 0.2 g, 0.15 g, 0.1 g, 0.09 g, 0.08 g, 0.07 g, 0.06 g, 0.05 g, 0.04 g, 0.03 g, 0.02 g, 0.01 g, 0.009 g, 0.008 g, 0.007 g, 0.006 g, 0.005 g, 0.004 g, 0.003 g, 0.002 g, 0.001 g, 0.0009 g, 0.0008 g, 0.0007 g, 0.0006 g, 0.0005 g, 0.0004 g, 0.0003 g, 0.0002 g, or 0.0001 g. In some embodiments, the amount of one or more compounds is more than 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g, 0.0006 g, 0.0007 g, 0.0008 g, 0.0009 g, 0.001 g, 0.0015 g, 0.002 g, 0.0025 g, 0.003 g, 0.0035 g, 0.004 g, 0.0045 g, 0.005 g, 0.0055 g, 0.006 g, 0.0065 g, 0.007 g, 0.0075 g, 0.008 g, 0.0085 g, 0.009 g, 0.0095 g, 0.01 g, 0.015 g, 0.02 g, 0.025 g, 0.03 g, 0.035 g, 0.04 g, 0.045 g, 0.05 g, 0.055 g, 0.06 g, 0.065 g, 0.07 g, 0.075 g, 0.08 g, 0.085 g, 0.09 g, 0.095 g, 0.1 g, , 0.15 g, 0.2 g, , 0.25 g, 0.3 g, , 0.35 g, 0.4 g, , 0.45 g, 0.5 g, 0.55 g, 0.6 g, , 0.65 g, 0.7 g, 0.75 g, 0.8 g, 0.85 g, 0.9 g, 0.95 g, 1 g, 1.5 g, 2 g, 2.5, 3 g, 3.5, 4 g, 4.5 g, 5 g, 5.5 g, 6 g, 6.5g, 7 g, 7.5g, 8 g, 8.5 g, 9 g, 9.5 g, or 10 g. In some embodiments, the amount of one or more compounds ranges from 0.0001 to 10 g, 0.0005 to 9 g, 0.001 to 8 g, 0.005 to 7 g, 0.01 to 6 g, 0.05 to 5 g, 0.1 to 4 g, 0.5 to 4 g, or 1 to 3 g. Method of Treatment Another embodiment provides a method for treating a disease in a subject, the method comprising administering the compound of Structure (I), or a stereoisomer, tautomer, or salt thereof to the subject. In certain embodiments, the disease is cancer. In some embodiments, the cancer is breast cancer (e.g., HER2+, triple negative), cervical cancer, lymphoma (e.g., Hodgkin's, non- Hodgkin's), myeloma (e.g., multiple myeloma), or urothelial cancer. In some embodiments, the disease or disorder is a cancerous tumor. For example, in certain embodiments the disclosure provides a method of treating cancer (e.g., breast cancer). In some embodiments, the cancer is HER2+ breast cancer, HR+ breast cancer, or triple negative breast cancer. One embodiment provides a method of contacting a cancer cell (e.g., in vivo or in vitro) with a compound of Structure (I). In some embodiments, the cancer cell is a breast cancer cell (e.g., HER2+, triple negative), a cervical cancer cell, a lymphoma cell (e.g., Hodgkin's, non- Hodgkin's), a myeloma cell (e.g., multiple myeloma), or a urothelial cancer cell. In some embodiments, the disease is an autoimmune disease. In some embodiments, the autoimmune disease is multiple sclerosis, diabetes, celiacs disease, Graves' disease, myasthenia gravis, Hashimotos encephalomyelitis, Neuromyelitis optica, inflammatory bowel disease, hemaphilia, lupus, autoimmune encephalomyelitis (EAE), or rheumatoid arthritis. Further therapeutic agents that can be combined with a compound of the disclosure are found in Goodman and Gilman's "The Pharmacological Basis of Therapeutics" Tenth Edition edited by Hardman, Limbird and Gilman or the Physician's Desk Reference, both of which are incorporated herein by reference in their entirety. The compound of Structure (I) described herein can be used in combination with the agents disclosed herein or other suitable agents, depending on the condition being treated. Hence, in some embodiments the one or more compounds of the disclosure will be co-administered with other agents as described above. When used in combination therapy, the compounds described herein are administered with the second agent simultaneously or separately. This administration in combination can include simultaneous administration of the two agents in the same dosage form, simultaneous administration in separate dosage forms, and separate administration. That is, a compound described herein and any of the agents described above can be formulated together in the same dosage form and administered simultaneously. Alternatively, a compound of the disclosure and any of the agents described above can be simultaneously administered, wherein both the agents are present in separate formulations. In another alternative, a compound of Structure (I) can be administered just followed by and any of the agents described above, or vice versa. In some embodiments of the separate administration protocol, a compound of the disclosure and any of the agents described above are administered a few minutes apart, or a few hours apart, or a few days apart. The examples and preparations provided below further illustrate and exemplify the compounds of Structure (I) and methods of preparing such compounds. It is to be understood that the scope of the present disclosure is not limited in any way by the scope of the following examples and preparations. In the following examples, and throughout the specification and claims, molecules, and moieties with a single stereocenter, unless otherwise noted, exist as a racemic mixture. Those molecules and moieties with two or more stereocenters, unless otherwise noted, exist as a racemic mixture of diastereomers. Single enantiomers / diastereomers may be obtained by methods known to those skilled in the art. A Representative DNA Synthesis Cycle Oligomerization is initiated, typically, through the removal of a protecting group (e.g., a dimethoxytrityl group, DMTr) to reveal a free –OH (hydroxyl) group (Step 1, DETRITYLATION). In a subsequent coupling step, a phosphoramidite monomer is introduced that reacts with the free OH group making a new covalent bond to phosphorus, with concomitant loss of the diisopropyl amine group (Step 2, COUPLING). The resultant, phosphite triester is oxidized (e.g., with I2and pyridine) to the more stable phosphate ester (Step 3, OXIDATION) and a capping step renders unreactive any remaining free OH groups (Step 4, CAPPING). The new product, phosphate oligomer, contains a DMTr protected OH group that can be deprotected to reinitiate the synthetic cycle so another phosphoramidite monomer can be appended to the oligomer. Customization occurs at step 2 through the choice of phosphoramidite monomer. The nature of L (i.e., a linker group) and M (e.g., a drug or linker-drug) in the scheme above are selected such that a desired compound of Structure (I) is synthesized. M can be optionally absent to incorporate desired spacing between M moieties. A person of ordinary skill in the art can select multiple monomer types to arrive at compounds of the disclosure containing multiple therapeutic agents and / or other moieties (e.g., fluorophores or chromophores) with concurrent variability in linker groups. EXAMPLES General Methods Mass spectral analysis is performed on a Waters / Micromass Quattro micro MS / MS system (in MS only mode) using MassLynx 4.1 acquisition software. Mobile phase used for LC / MS on dyes is 100 mM 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), 8.6 mM triethylamine (TEA), pH 8. Phosphoramidites and precursor molecules are also analyzed using a Waters Acquity UHPLC system with a 2.1 mm × 50 mm Acquity BEH-C18 column held at 45 °C, employing an acetonitrile / water mobile phase gradient. Molecular weights for monomer intermediates are obtained using tropylium cation infusion enhanced ionization on a Waters / Micromass Quattro micro MS / MS system (in MS only mode). Excitation and emission profiles experiments are recorded on a Cary Eclipse spectra photometer. All reactions are carried out in oven dried glassware under a nitrogen atmosphere unless otherwise stated. Commercially available DNA synthesis reagents are purchased from Glen Research (Sterling, VA). Anhydrous pyridine, toluene, dichloromethane, diisopropylethyl amine, triethylamine, acetic acid, pyridine, and THF are purchased from Aldrich. All other chemicals are purchase from Aldrich or TCI and are used as is with no additional purification. EXAMPLE 1 SYNTHESIS OF COMPOUNDS OF STRUCTURE (I) Stock Solution Preparation Borate buffer prepared at 250 mM, pH 10 M1-NHS or M2-NHS solution prepared at 350 mM (300 mg in 1.35 mL DMSO: acetonitrile at 25:75) Solid Phase Synthesis Compounds of Structure (I) are prepared on the DNA synthesizer via solid support using standard DNA synthesis techniques (i.e., DMT protected 2-cyanoethyl phosphoramidite). The polymer is removed from the solid support with ammonium hydroxide and lyophilized to a paste. 250 mg aliquots are reconstituted in water. A small aliquot is removed, and serial dilutions are prepared in 100 mM NaHCO3 at pH 9 to determine concentration (A 263 ε = 10,000). Final stock concentration is found to be 14.5 mM. Coupling Reaction In 50 mL centrifuge tube equipped with magnetic stir bar is placed water (1.110 µL), borate buffer (1.800 µL), compound of Structure (I) in final stock solution (466 µL), acetonitrile (137.5 µL), triethylamine (313 µL) and M1-NHS or M2-NHS solution (675 µL). The tube is wrapped in aluminum foil and the mixture stirred overnight at room temperature. Size Exclusion Filtration To an Amicon Ultra-15 Centrifugal filter (Millipore UFC900324, MW cutoff = 3000) is added 1 mL of water. The crude reaction from the coupling reaction (4.5 mL) is added to the filtration setup. The reaction vessel is rinsed 2 × with 4 mL of 100 mM NaOH and the rinseates are transferred to the filtration setup. The filtration setup is centrifuged at max speed (3220 g, swing bucket, 30 minutes). The filtrate is removed and the retentate treated with an additional 10 mL of 100 mM NaOH. The filtration setup is centrifuged as before. Again, the filtrate is removed and a third 10 mL 100 mM NaOH aliquot is added to the retentate. The setup is centrifuged as before, and the filtrate removed. A fourth 10 mL 100 mM NaOH aliquot is added to the retentate and centrifuged as before. The filtrate is removed, and 10 mL of water are added to the filtration setup. The mixture is centrifuged as before. The retentate is removed, the filtration vessel is washed with water and the rinesates are added to the final volume (3.5 mL). The desired product is confirmed by LC-MS and absorbance is used to determine concentration.

[0005] EXAMPLE 2 ACTIVATION AND ANTIBODY CONJUGATION OF COMPOUND OF STRUCTURE (I) The maleimide functionalized compound of Structure (I) is prepared according to the method described herein. In parallel, a Brentuximab antibody is treated to reduce disulfide bonds. The reduced antibody is reacted with a compound of Structure (I) in a 5:1 molar ratio (polymer to antibody). The reaction results in a final product having a polymer to antibody ratio of 1:1 as detected by size exclusion chromatography. Alternatively, the reduced antibody is treated with bis-maleimidoethane ("BMOE"). The resultant product is then reacted with a compound of Structure (I) having a terminal -SH group. Again, the compound of Structure (I) is reacted with the antibody in a 5:1 molar ratio (polymer to antibody) and results in a final product having a polymer to antibody ratio of 1:1 as detected by size exclusion chromatography. In some embodiments, anti-CD33, anti-CD30, anti-CD70, or anti-CD123 is used in place of the UCHT-1 antibody. EXAMPLE 3 Cytotoxicity Assay Method & procedure Karpas 299, cell passage number 6 cell suspension was prepared. Seeded 5,000 cells / well in a 96-well plate was prepared and then the cells were treated with the compound disclosed in the present application at various concentrations (i.e., 0.01, 0.04, 0.1, 0.2, 0.4, 0.6, 1, 4, 10 and 100 ng / mL). Titration in RPMI 1640 media + 10% FBS was used. Titration was made from a 10 µg / mL antibody stock solution (based on protein concentration). The plates were incubated for 96 hours and a viablility dye (Alamar Blue) was added to differentiate live and dead cells, measuring the fluorescence at 570nm on Tecan plate reader, and calculating the percentage of cytotoxicity by comparing treated cells to control wells. The assay plate was set up with each well in triplicate and the assay duration was 96 hours. The antibody conjugates were added day of plating. IC50 Calculation: IC50values are determined using GraphPad software. The data were entered as an X-Y plot into the software as percent inhibition for each concentration of the drug. The concentration values of the drug were log transformed and the nonlinear regression was carried out using the “sigmoidal dose-response (variable slope)” option within the GraphPad software to model the data and calculate IC50 values. The IC50values reported are the concentration of drug at which 50% inhibition was reached. The IC50 values are based on the average of 2-3 assays and summarized in Table 1. Cytotoxicity dose-response graphs of the tested compounds are illustrated in FIG.2. Table 1: Effect of compounds of the present disclosure on Brentuximab IC50 Average IC50Fold Diff. Compound DOL DAR (ng / ml) from control **Mal -HEG-(HEG-[dU-C6-NH- 6.1 18.3 0.99 2.2 MMAE])3-HEG-dT **Mal -HEG-(HEG-[dU-C6-NH- 5.18 25.9 0.46 4.7 MMAE])5-HEG-dT **Mal -HEG-(HEG-[dU-C6-NH- 3.7 25.9 0.37 5.8 MMAE])7-HEG-dT **Mal -HEG-(HEG-[dU-C6-NH- 3.2 32 0.26 8.3 MMAE])10-HEG-dT *Mal-HEG-(HEG-HEG-HEG-[dU-C6- 5.14 25.7 1.78 1.2 NH-MMAE])5-HEG-dT *Mal -C6-[dU-C6-NH-MMAE] -(HEG- HEG-HEG-[dU-C6-NH-MMAE])4-HEG- 4.8 24 0.95 2.3 dT *Mal -TEG-[dU-C6-NH-MMAE]-(HEG- HEG-HEG-[dU-C6-NH-MMAE])4-HEG- 4.86 24.3 0.93 2.3 dT *Mal -HEG-[dU-C6-NH-MMAE]-(HEG- HEG-HEG-[dU-C6-NH-MMAE])4-HEG- 4.91 24.6 0.96 2.2 dT *Mal-HEG-HEG-[dU-C6-NH-MMAE]- (HEG-HEG-HEG-[dU-C6-NH- 5.15 25.8 1.17 1.8 MMAE])4-HEG-dT Val-Cit-PAB-MMAE 3.5 3.5 2.15 0 DOL: degree of labeling was calculated by UV absorption method DAR: Drug antibody ratio *: average of 2 assays ** average of 3 assays Val-Cit-PAB-MMAE structure: UV absorbance method: Degree of labeling (DOL) was identified by UV-Vis analysis. Absorbance was measured at 280 nm and 248 nm and the was used to calculate DOL: , εAb(extinction coefficient of antibody) = 234,150 M-1cm-1at 280nm εAb (extinction coefficient of antibody) = 94,130 M-1cm-1at 248nm The extinction coefficients of compounds at 280 and 248 nm used to calculate DOL are included in Table 2 below: Table 2: extinction coefficients of compounds at 280 nm and 248 nm Extinction coefficient of compound εpolyεpoly280nm 248nm p = 3 47448 75036 p = 5 76448 121836 p = 7 105448 168636 p = 10 148948 238836 All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Applicant Data Sheet, including U.S. Provisional Patent Application No.63 / 555,548, filed February 20, 2024, are incorporated herein by reference, in their entirety to the extent not inconsistent with the present description. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments. From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. Accordingly, the disclosure is not limited except as by the appended claims.

Claims

CLAIMS 1. A compound having the following Structure (I):or a salt, stereoisomer, or tautomer thereof, wherein: R1has one of the following structures:A is an antibody; R2has the following structure:L1at each occurrence, independently has one of the following structures:L2at each occurrence, independently has one of the following structures:L3at each occurrence, independently has one of the following structures:R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, an cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor; L4at each occurrence, independently one the following structure:v is an integer ranging from 1-30; n is, at each occurrence, independently an integer ranging from 0 to 12; m is, at each occurrence, independently an integer ranging from 0 to 12; p is, at each occurrence, independently an integer ranging from 1 to 30; and w is an integer ranging from 0 to 12.

2. The compound of claim 1, wherein R1has one of the following structures:

3. The compound of any one of claims 1-2, wherein R1has the following structure: .

4. The compound of any one of claims 1-2, wherein R1has the following structure: .

5. The compound of any one of claims 1-2, wherein R1has the following structure: .

6. The compound of any one of claims 1-2, wherein R1has the following structure: .

7. The compound of any one of claims 1-6, wherein at least one occurrence of L1has one of the following structures:or .

8. The compound of any one of claims 1-7, wherein at least one occurrence of L1has one of the following structures:

9. The compound of any one of claims 1-8, wherein each occurrence of L1has one of the following structures:

10. The compound of any one of claims 1-9, wherein each occurrence of L1has one of the following structures:

11. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure:.

12. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure: .

13. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure:.

14. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure:.

15. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure:.

16. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure: O OPO O .

17. The compound of any one of claims 1-10, wherein each occurrence of L1has the following structure: .

18. The compound of any one of claims 1-17, wherein at least one occurrence of L2has one of the following structures:

19. The compound of any one of claims 1-18, wherein at least one occurrence of L2has one of the following structures:

20. The compound of any one of claims 1-19, wherein each occurrence of L2has one of the following structures:

21. The compound of any one of claims 1-20, wherein each occurrence of L2has one of the following structures:

22. The compound of any one of claims 1-21, wherein each occurrence of L2the following structure:.

23. The compound of any one of claims 1-21, wherein each occurrence of L2the following structure:.

24. The compound of any one of claims 1-21, wherein each occurrence of L2the following structure:.

25. The compound of any one of claims 1-21, wherein each occurrence of L2the following structure:.

26. The compound of any one of claims 1-25, wherein at least one occurrence of L3has one of the following structures:wherein: R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, a cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor.

27. The compound of any one of claims 1-26, wherein each occurrence of L3has one of the following structures:wherein: R3is D or -L-D; L is a linker comprising an alkylene linker, a heteroalkylene linker, a heteroatomic linker, an cycloalkylene linker, a heterocyclylene linker, an arylene linker, a heteroarylene linker, or combinations thereof; and D is a biologically active moiety selected from the group consisting of an antimetabolite, an antimiotic, an antitumor antibiotic, a bisphosphonate, a chemotherapeutic, an antineoplastic, an alkylating agent, a DNA-repair enzyme inhibitor, a histone deacetylase inhibitor, a hormone, a demethylating agent, a Janus-associated kinase inhibitor, a phosphoinositide 3-kinase inhibitor, a proteasome inhibitor, a selective inhibitor of nuclear export, and a tyrosine kinase inhibitor.

28. The compound of any one of claims 1-27, wherein at least one occurrence of D has one of the following structures:

29. The compound of any one of claims 1-27, wherein at least one occurrence of L3has one of the following structures:MMAE has the following structure:

30. The compound of any one of claims 1-27, wherein each occurrence of L3has one of the following structures:wherein: L' has the following structure:MMAE has the following structure:

31. The compound of any one of claims 1-30, wherein at least one occurrence of L4has one of the following structures:, , or .

32. The compound of any one of claims 1-31, wherein each occurrence of L4has one of the following structures: , , or .

33. The compound of any one of claims 1-32, wherein each occurrence of L4has the following structure: .

34. The compound of any one of claims 1-33, wherein n is 0, 1, 2, or 3.

35. The compound of any one of claims 1-34, wherein m is 1, 2, 3, 4 or 5.

36. The compound of any one of claims 1-35, wherein p is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

37. The compound of any one of claims 1-36, wherein w is 0, 1, 2, or 3.

38. The compound of claim 1, wherein the compound has one of the following formulae: C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(HEG-HEG-HEG-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-HEG-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT,C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(HEG-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-HEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(HEG-HEG-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)3-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)5-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)7-HEG-dT, C6SS-HEG-(PEG1K-[C6-NH2]dU)10-HEG-dT, C6SS-HEG-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT,C6SS-PEG1K-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-TEG-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C6-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C4-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C3-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-C2-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-[C6-NH2]dU-(PEG1K-[C6-NH2]dU)4-HEG-dT, C6SS-HEG-(HEG-[C6-NH2dU])5-HEG-dT, C6SS-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, HS-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, or Mal-HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT wherein: Mal has the following structure:HS has the following structure:C6SS has the following structure:TEG has the following structure:HEG has the following structure:PEG1K has the following structure:[C6-NH2]dU has the following structure:[dU-C6-NH-MMAE] has the following structure:wherein: L' has the following structure:MMAE has the following structure:dT has the following structure:C6 has the following structure:C4 has the following structure:C3 has the following structure:C2 has the following structure:TEG, HEG, PEG1K, [C6-NH2]dU, [dU-C6-NH-MMAE], C6, C4, C3, and C2 are connected from left to right in the shown orientations.

39. The compound of claim 1, wherein the compound has one of the following formulae: C6SS-Y-([C6-NH2]dU)3-HEG-dT, C6SS-Y-([C6-NH2]dU)5-HEG-dT, C6SS-Y-([C6-NH2]dU)7-HEG-dT, or C6SS-Y-([C6-NH2]dU)10-HEG-dT, wherein: Y is a direct bond, C6, C4, C3, C2, TEG, PEG1K, HEG, (HEG)2, or (HEG)3; [C6-NH2]dU has the following structure:C6SS has the following structure:TEG has the following structure:HEG has the following structure:PEG1K has the following structure:C6 has the following structure:C4 has the following structure:C3 has the following structure:C2 has the following structure:dT has the following structure:TEG, HEG, PEG1K, [C6-NH2]dU, C6, C4, C3, and C2 are connected from left to right in the shown orientations. .

40. The compound of claim 1, wherein the compound has one of the following formulae: C6SS-HEG-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-PEG1K-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-TEG-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C6-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C4-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C3-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, C6SS-C2-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, or C6SS-[C6-NH2]dU-((HEG)X[C6-NH2]dU)3-HEG-dT, wherein:X is an integer ranging from 1 to 6; C6SS has the following structure:TEG has the following structure:HEG has the following structure:PEG1K has the following structure:[C6-NH2]dU has the following structure:C6 has the following structure:C4 has the following structure:C3 has the following structure:C2 has the following structure:dT has the following structure:TEG, HEG, PEG1K, [C6-NH2]dU, C6, C4, C3, and C2 are connected from left to right in the shown orientations.

41. The compound of claim 1, wherein the compound has one of the following formulae: Mal-HEG-(HEG-HEG-HEG-[dU-C6-NH-MMAE])5-HEG-dT, Mal-HEG-HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG- dT, Mal -HEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -TEG-[dU-C6-NH-MMAE]-(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -C6-[dU-C6-NH-MMAE] -(HEG-HEG-HEG-[dU-C6-NH-MMAE])4-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])3-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])5-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])7-HEG-dT, Mal -HEG-(HEG-[dU-C6-NH-MMAE])10-HEG-dT, wherein: Mal has the following structure:TEG has the following structure: ; HEG has the following structure: ;C6 has the following structure:[dU-C6-NH-MMAE] has the following structure:wherein: L' has the following structure:MMAE has the following structure:dT has the following structure:TEG, HEG, PEG1K, [dU-C6-NH-MMAE], and C6 are connected from left to right in the shown orientations.

42. The compound of any one of claims 1-37, wherein the antibody is trastuzumab, gemtuzumab, brentuximab, vorsetuzumab, lorvotuzumab, cantuzumab, bivatuzumabor inotuzumab, or vadastuximab.

43. A pharmaceutical composition comprising the compound of any one of claims 1- 42, or a stereoisomer, tautomer, or salt thereof and a pharmaceutically acceptable excipient.

44. A method for treating a disease in a subject, the method comprising administering the compound of any one of claims 1-42, or a stereoisomer, tautomer, or salt thereof to the subject.

45. The method of claim 44, wherein the disease is cancer.

46. The method of claim 45, wherein the cancer is breast cancer, cervical cancer, lymphoma, myeloma, or urothelial cancer.

47. The method of any one of claims 44, wherein the disease is an autoimmune disease.

48. The method of claim 47, wherein the autoimmune disease is multiple sclerosis, diabetes, celiacs disease, Graves’ disease, myasthenia gravis, Hashimotos encephalomyelitis, Neuromyelitis optica, inflammatory bowel disease, hemaphilia, lupus, autoimmune encephalomyelitis (EAE), or rheumatoid arthritis.

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