WO2021067820A1 - Formulation of antibody-drug conjugate - Google Patents

Abstract

The present disclosure relates to formulations of antibody-drug conjugates (ADCs) and methods of preparation and use thereof.

Description

FORMULATION OF ANTIBODY-DRUG CONJUGATE CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority benefit of U.S. Provisional Application Serial No.62/911,097, filed on October 4, 2019, the content of which is incorporated herein by reference in its entirety. SUBMISSION OF SEQUENCE LISTING ON ASCII TEXT FILE [0002] The content of the following submission on ASCII text file is incorporated herein by reference in its entirety: a computer readable form (CRF) of the Sequence Listing (file name: 761682002340SEQLIST.TXT, date recorded: September 29, 2020, size: 13 KB). FIELD [0003] The present disclosure relates to formulations of antibody-drug conjugates (ADCs) and methods of preparation and use thereof. BACKGROUND [0004] ADCs are complex engineered therapeutics that contain antibodies directed toward disease-associated antigens to which highly potent cytotoxic agents are attached typically via linkers. One class of ADCs that is sufficiently active, while having a suitable toxicity profile, to warrant clinical development includes the camptothecin conjugates (i.e., camptothecin-containing ADCs). [0005] Like other protein pharmaceuticals, however, antibodies are prone to degradation such as deamidation, fragmentation, and aggregation. In addition, after conjugation, the properties of antibodies are often altered, leading to additional challenges for ADCs. For example, one problem associated with formulations of certain camptothecin conjugates is that they may be prone to liquid-liquid phase separation (LLPS). LLPS is the creation of two distinct phases from a single homogeneous mixture. ADCs are concentrated in one phase created by LLPS and thus are more prone to aggregation. Therefore, there is a need for formulations of camptothecin conjugates that exhibit no or minimal extent of LLPS and are stable during manufacture, transportation, and storage. The present disclosure addresses these and other needs. SUMMARY [0006] In one aspect, provided herein is a formulation containing a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, wherein the formulation has a pH of between about 4.0 and about 7.0. In some embodiments, the formulation is a lyophilized formulation. In some embodiments, the formulation is a reconstituted formulation. [0007] In another aspect, provided herein is a method of preparing a formulation containing a camptothecin conjugate of Formula (IC) or a pharmaceutically acceptable salt thereof. [0008] In another aspect, provided herein is a method of reducing LLPS of an aqueous formulation containing a camptothecin conjugate of Formula (IC) or a pharmaceutically acceptable salt thereof. [0009] In another aspect, provided herein is a method of treating cancer or an autoimmune disease, the method including administering to an individual in need thereof a formulation containing a camptothecin conjugate of Formula (IC) or a pharmaceutically acceptable salt thereof. Also provided herein is a formulation containing a camptothecin conjugate of Formula (IC) or a pharmaceutically acceptable salt thereof for use in treating cancer or an autoimmune disease. [0010] In another aspect, provided is a kit containing a formulation containing a camptothecin conjugate of Formula (IC) or a pharmaceutically acceptable salt thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG.1 shows the percent HMW as determined by size exclusion chromatography (SEC) at the initial time point (T0) and 7 days after storage at 5 ºC for various formulations. [0012] FIG.2 shows the percent LMW as determined by SEC at the initial time point (T0) and 7 days after storage at 5 ºC for various formulations. [0013] FIG.3 shows the percent Acidic as determined by imaged capillary isoelectric focusing (icIEF) at the initial time point (T0) and 7 days after storage at 5 ºC for various formulations. [0014] FIG.4 shows the percent Basic as determined by icIEF at the initial time point (T0) and 7 days after storage at 5 ºC for various formulations. [0015] FIG.5 shows the percent HMW as determined by SEC at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC for various formulations. [0016] FIG.6 shows the percent LMW as determined by SEC at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC for various formulations. [0017] FIG.7 shows the percent Acidic as determined by icIEF at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC for various formulations. [0018] FIG.8 shows the percent Basic as determined by icIEF at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC for various formulations. [0019] FIG.9 shows the percent HMW as determined by SEC was conducted at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC) at 40 ºC for various formulations. [0020] FIG.10 shows the percent LMW as determined by SEC was conducted at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC) for various formulations. [0021] FIG.11 shows the percent Acidic as determined by icIEF was conducted at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC) at 40 ºC for various formulations. [0022] FIG.12 shows the percent Basic as determined by icIEF was conducted at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC) for various formulations. [0023] FIG.13 shows the percent HMW as determined by SEC at the initial time point (T0), 3 days, and 5 days after storage at 40 ºC for various formulations. [0024] FIG.14 shows the percent LMW as determined by SEC at the initial time point (T0), 3 days, and 5 days after storage at 40 ºC for various formulations. [0025] FIG.15 shows the percent HMW as determined by SEC at the initial time point (T0), 3 days, and 5 days after storage at 40 ºC for various formulations. [0026] FIG.16 shows the percent LMW as determined by SEC at the initial time point (T0), 3 days, and 5 days after storage at 40 ºC for various formulations. [0027] FIG.17 shows the percent HMW as determined by SEC at the initial time point (T0), 7 days, 14 days, and 28 days after storage at 40 ºC for various formulations. [0028] FIG.18 shows the percent LMW as determined by SEC at the initial time point (T0), 7 days, 14 days, and 28 days after storage at 40 ºC for various formulations. DETAILED DESCRIPTION [0029] Provided herein are formulations of camptothecin conjugates and methods of preparation and use thereof. The formulations provided herein may exhibit no or minimal extent of LLPS and have improved stability. Definitions [0030] Unless stated otherwise, the following terms and phrases as used herein are intended to have the following meanings. When trade names are used herein, the trade name includes the product formulation, the generic drug, and the active pharmaceutical ingredient(s) of the trade name product, unless otherwise indicated by context. [0031] The term “antibody” as used herein is used in the broadest sense and specifically covers intact monoclonal antibodies, polyclonal antibodies, monospecific antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments that exhibit the desired biological activity. The native form of an antibody is a tetramer and consists of two identical pairs of immunoglobulin chains, each pair having one light chain and one heavy chain. In each pair, the light and heavy chain variable regions (VL and VH) are together primarily responsible for binding to an antigen. The light chain and heavy chain variable domains consist of a framework region interrupted by three hypervariable regions, also called “complementarity determining regions” or “CDRs.” The constant regions may be recognized by and interact with the immune system. (see, e.g., Janeway et al., 2001, Immunol. Biology, 5th Ed., Garland Publishing, New York). An antibody can be of any type (e.g., IgG, IgE, IgM, IgD, and IgA), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass. The antibody can be derived from any suitable species. In some embodiments, the antibody is of human or murine origin. An antibody can be, for example, human, humanized or chimeric. [0032] The term “monoclonal antibody” as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for possible naturally-occurring mutations that may be present in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic site. The modifier “monoclonal” indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not to be construed as requiring production of the antibody by any particular method. [0033] An “intact antibody” is one which comprises an antigen-binding variable region as well as a light chain constant domain (C_L) and heavy chain constant domains, C_H1, C_H2, C_H3 and C_H4, as appropriate for the antibody class. The constant domains may be native sequence constant domains (e.g., human native sequence constant domains) or amino acid sequence variant thereof. [0034] An “antibody fragment” comprises a portion of an intact antibody, comprising the antigen-binding or variable region thereof. Examples of antibody fragments include Fab, Fab’, F(ab’)2, and Fv fragments, diabodies, triabodies, tetrabodies, linear antibodies, single- chain antibody molecules, scFv, scFv-Fc, multispecific antibody fragments formed from antibody fragment(s), a fragment(s) produced by a Fab expression library, or an epitope- binding fragments of any of the above which immunospecifically bind to a target antigen (e.g., a cancer cell antigen, a viral antigen or a microbial antigen). [0035] An “antigen” is an entity to which an antibody specifically binds. [0036] The terms “specific binding” and “specifically binds” mean that the antibody or antibody derivative will bind, in a highly selective manner, with its corresponding epitope of a target antigen and not with the multitude of other antigens. Typically, the antibody or antibody derivative binds with an affinity of at least about 1x10^-7 M, and preferably 10^-8 M to 10^-9 M, 10^-10 M, 10^-11 M, or 10^-12 M and binds to the predetermined antigen with an affinity that is at least two-fold greater than its affinity for binding to a non-specific antigen (e.g., BSA, casein) other than the predetermined antigen or a closely-related antigen. [0037] The term "inhibit" or "inhibition of" means to reduce by a measurable amount, or to prevent entirely. [0038] The term “therapeutically effective amount” refers to an amount of a conjugate effective to treat a disease or disorder in a mammal. In the case of cancer, the therapeutically effective amount of the conjugate may reduce the number of cancer cells; reduce the tumor size; inhibit (i.e., slow to some extent and preferably stop) cancer cell infiltration into peripheral organs; inhibit (i.e., slow to some extent and preferably stop) tumor metastasis; inhibit, to some extent, tumor growth; and/or relieve to some extent one or more of the symptoms associated with the cancer. To the extent the drug may inhibit growth and/or kill existing cancer cells, it may be cytostatic and/or cytotoxic. For cancer therapy, efficacy can, for example, be measured by assessing the time to disease progression (TTP) and/or determining the response rate (RR). [0039] The term “substantial” or “substantially” refers to a majority, i.e. >50% of a population, of a mixture or a sample, preferably more than 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97 %, 98%, or 99% of a population. [0040] The terms “cancer” and “cancerous” refer to or describe the physiological condition or disorder in mammals that is typically characterized by unregulated cell growth. A “tumor” comprises one or more cancerous cells. [0041] An “autoimmune disease” as used herein refers to a disease or disorder arising from and directed against an individual’s own tissues or proteins. [0042] “Patient” as used herein refers to a subject to whom is administered a Camptothecin Conjugate of the present invention. Patient includes, but are not limited to, a human, rat, mouse, guinea pig, non-human primate, pig, goat, cow, horse, dog, cat, bird and fowl. Typically, the patient is a rat, mouse, dog, human or non-human primate, more typically a human. [0043] The terms “treat” or “treatment,” unless otherwise indicated by context, refer to therapeutic treatment and prophylactic wherein the object is to inhibit or slow down (lessen) an undesired physiological change or disorder, such as the development or spread of cancer. For purposes of this invention, beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishment of extent of disease, stabilized (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. “Treatment” can also mean prolonging survival as compared to expected survival if not receiving treatment. Those in need of treatment include those already with the condition or disorder as well as those prone to have the condition or disorder. [0044] In the context of cancer, the term “treating” includes any or all of: killing tumor cells; inhibiting growth of tumor cells, cancer cells, or of a tumor; inhibiting replication of tumor cells or cancer cells, lessening of overall tumor burden or decreasing the number of cancerous cells, and ameliorating one or more symptoms associated with the disease. [0045] In the context of an autoimmune disease, the term “treating” includes any or all of: inhibiting replication of cells associated with an autoimmune disease state including, but not limited to, cells that produce an autoimmune antibody, lessening the autoimmune- antibody burden and ameliorating one or more symptoms of an autoimmune disease. [0046] The term “pharmaceutically acceptable form” as used herein refers to a form of a disclosed compound including, but is not limited to, pharmaceutically acceptable salts, esters, hydrates, solvates, polymorphs, isomers, prodrugs, and isotopically labeled derivatives thereof. In one embodiment, a "pharmaceutically acceptable form" includes, but is not limited to, pharmaceutically acceptable salts, esters, prodrugs and isotopically labeled derivatives thereof. In some embodiments, a "pharmaceutically acceptable form" includes, but is not limited to, pharmaceutically acceptable isomers and stereoisomers, prodrugs and isotopically labeled derivatives thereof. [0047] In certain embodiments, the pharmaceutically acceptable form is a pharmaceutically acceptable salt. The term “pharmaceutically acceptable salt,” as used herein, refers to pharmaceutically acceptable organic or inorganic salts of a compound (e.g., a Drug, Drug-Linker, or a Camptothecin Conjugate). In some aspects, the compound can contain at least one amino group, and accordingly acid addition salts can be formed with the amino group. Exemplary salts include, but are not limited to, sulfate, trifluoroacetate, citrate, acetate, oxalate, chloride, bromide, iodide, nitrate, bisulfate, phosphate, acid phosphate, isonicotinate, lactate, salicylate, acid citrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, and pamoate (i.e., 1,1’-methylene-bis-(2-hydroxy-3-naphthoate)) salts. A pharmaceutically acceptable salt may involve the inclusion of another molecule such as an acetate ion, a succinate ion or other counterion. The counterion may be any organic or inorganic moiety that stabilizes the charge on the parent compound. Furthermore, a pharmaceutically acceptable salt may have more than one charged atom in its structure. Instances where multiple charged atoms are part of the pharmaceutically acceptable salt can have multiple counter ions. Hence, a pharmaceutically acceptable salt can have one or more charged atoms and/or one or more counterion. [0048] The term “stable”, as used herein, refers to a formulation in which the antibody or ADC retains its physical and chemical integrity for a sufficient period of time to be useful for the purposes detailed herein (e.g., therapeutic or prophylactic administration to a subject). [0049] As used herein, the singular form “a,” “an,” and “the” comprises plural references unless indicated otherwise. [0050] As used herein, and unless otherwise specified, the term “about,” when used in connection with a specified value, is meant to include a value within 10%, within 5%, within 4%, within 3%, within 2%, within 1%, within 0.5%, or within 0.1% of the specified value. Reference to “about” a value or parameter herein comprises (and describes) aspects that are directed to that value or parameter per se. For example, description referring to “about X” comprises description of “X.” [0051] Reference to a numerical range herein (e.g., "X to Y" or "from X to Y") includes the endpoints defining the range and all values falling within the range. [0052] It is understood that embodiments, aspects and variations described herein also include “consisting” and/or “consisting essentially of” embodiments, aspects and variations. [0053] Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. [0054] All publications, including patent documents, scientific articles and databases, referred to in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were individually incorporated by reference. If a definition set forth herein is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporated by reference, the definition set forth herein prevails over the definition that is incorporated herein by reference. [0055] Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “for example” or “such as” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. Formulations [0056] In one aspect, provided herein is a formulation containing a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, wherein the formulation has a pH of between about 4.0 and about 7.0. In some embodiments, the formulation contains a buffer containing acetic acid, an acetate salt (e.g., sodium acetate), a succinate salt (e.g., sodium succinate), a citrate salt (e.g., sodium citrate), an amino acid (e.g., histidine, aspartic acid, or glutamic acid), or a sulfonic acid (e.g., 2-(N- morpholino)ethanesulfonic acid or 3-(N-morpholino)propanesulfonic acid). In some embodiments, the formulation contains a Good’s buffer described by Good et al. (1966) Biochem., 5 (2): 467-477, Good et al. (1972) Methods Enzymol., 24: 53–68, and Ferguson et al., (1980) Anal. Biochem., 104 (2): 300–310. Examples of Good’s buffers include, but are not limited to, 2-(N-morpholino)ethanesulfonic acid (MES), Bis-tris methane, N-(2-acetamido)iminodiacetic acid (ADA), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), Bis-tris propane, piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), 2-Hydroxy-3- morpholinopropanesulfonic acid (MOPSO), Cholamine chloride, 3- morpholinopropanesulfonic acid (MOPS), N-tris(hydroxymethyl) methyl-2- aminoethanesulfonic acid (TES), 2,4-(2-hydroxyethyl)-1-piperazinyl ethanesulfonic acid (HEPES), 3-[N-Tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid (TAPSO), triethanolamine (TEA), 3,4-(2-hydroxyethyl)-1-piperazinyl propanesulfonic acid (HEPPS), N-tris(hydroxymethyl) methylglycine (Tricine), tris(hydroxymethyl)aminomethane (TRIS), Glycinamide, Glycylglycine, N-(2-Hydroxyethyl)piperazine-N'-(4-butanesulfonic acid) (HEPBS), N,N-bis (2-hydroxyethyl)glycine (Bicine), N-Tris(hydroxymethyl)methyl-3- aminopropanesulfonic acid (TAPS), N-cyclohexyl-2-aminoethanesulfonic acid (CHES), aminomethyl propanol (AMP), and N-cyclohexyl-3-aminopropanesulfonic acid (CAPS). [0057] In some embodiments, y is 1, 2, 3, or 4. In some embodiments, y is 1 or 2. In some embodiments, y is 1 or 3. In some embodiments, y is 1 or 4. In some embodiments, y is 2 or 3. In some embodiments, y is 2 or 4. In some embodiments, y is 3 or 4. In some embodiments, y is 1, 2, or 3. In some embodiments, y is 2, 3, or 4. In some embodiments, y is 1. In some embodiments, y is 2. In some embodiments, y is 3. In some embodiments, y is 4. [0058] In some embodiments, when y is 1, provided herein is a formulation containing a camptothecin conjugate of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, wherein the formulation has a pH of between about 4.0 and about 7.0. In some embodiments, the formulation contains a buffer containing acetic acid, an acetate salt (e.g., sodium acetate), a succinate salt (e.g., sodium succinate), a citrate salt (e.g., sodium citrate), an amino acid (e.g., histidine, aspartic acid, or glutamic acid), or a sulfonic acid (e.g., 2-(N- morpholino)ethanesulfonic acid or 3-(N-morpholino)propanesulfonic acid). In some embodiments, the formulation contains a Good’s buffer described by Good et al. (1966) Biochem., 5 (2): 467-477, Good et al. (1972) Methods Enzymol., 24: 53–68, and Ferguson et al. (1980) Anal. Biochem., 104 (2): 300–310. Examples of Good’s buffers include, but are not limited to, 2-(N-morpholino)ethanesulfonic acid (MES), Bis-tris methane, N-(2-acetamido)iminodiacetic acid (ADA), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), Bis-tris propane, piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), 2-Hydroxy-3- morpholinopropanesulfonic acid (MOPSO), Cholamine chloride, 3- morpholinopropanesulfonic acid (MOPS), N-tris(hydroxymethyl) methyl-2- aminoethanesulfonic acid (TES), 2,4-(2-hydroxyethyl)-1-piperazinyl ethanesulfonic acid (HEPES), 3-[N-Tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid (TAPSO), triethanolamine (TEA), 3,4-(2-hydroxyethyl)-1-piperazinyl propanesulfonic acid (HEPPS), N-tris(hydroxymethyl) methylglycine (Tricine), tris(hydroxymethyl)aminomethane (TRIS), Glycinamide, Glycylglycine, N-(2-Hydroxyethyl)piperazine-N'-(4-butanesulfonic acid) (HEPBS), N,N-bis (2-hydroxyethyl)glycine (Bicine), N-Tris(hydroxymethyl)methyl-3- aminopropanesulfonic acid (TAPS), N-cyclohexyl-2-aminoethanesulfonic acid (CHES), aminomethyl propanol (AMP), and N-cyclohexyl-3-aminopropanesulfonic acid (CAPS). [0059] In some embodiments, L is a monoclonal antibody. Useful monoclonal antibodies are homogeneous populations of antibodies to a particular antigenic determinant (e.g., a cancer cell antigen, a viral antigen, a microbial antigen, a protein, a peptide, a carbohydrate, a chemical, nucleic acid, or fragments thereof). A monoclonal antibody (mAb) to an antigen- of-interest can be prepared by using any technique known in the art, which provides for the production of antibody molecules by continuous cell lines in culture. Examples of monoclonal antibodies include, but are not limited to, human monoclonal antibodies, humanized monoclonal antibodies, or chimeric human-mouse (or other species) monoclonal antibodies. The antibodies include full-length antibodies and antigen binding fragments thereof. Human monoclonal antibodies can be made by any of numerous techniques known in the art (e.g., Teng et al., 1983, Proc. Natl. Acad. Sci. USA.80:7308-7312; Kozbor et al., 1983, Immunology Today 4:72-79; and Olsson et al., 1982, Meth. Enzymol.92:3-16). [0060] In some embodiments, L is a functionally active fragment, derivative or analog of an antibody that immunospecifically binds to target cells (e.g., cancer cell antigens, viral antigens, or microbial antigens) or other antibodies bound to tumor cells or matrix. In this regard, “functionally active” means that the fragment, derivative or analog is able to immunospecifically binds to target cells. To determine which CDR sequences bind the antigen, synthetic peptides containing the CDR sequences can be used in binding assays with the antigen by any binding assay method known in the art (e.g., the BIA core assay) (See, e.g., Kabat et al., 1991, Sequences of Proteins of Immunological Interest, Fifth Edition, National Institute of Health, Bethesda, Md; Kabat E et al., 1980, J. Immunology 125(3):961- 969). Examples of fragments of antibodies include, but are not limited to, F(ab’)₂ fragments, Fab fragments, Fvs, single chain antibodies, diabodies, triabodies, tetrabodies, scFv, scFv- FV, or any other molecule with the same specificity as the antibody. [0061] In some embodiments, L is a recombinant antibody. Recombinant antibodies, such as chimeric and humanized monoclonal antibodies, comprise both human and non-human portions, which can be made using standard recombinant DNA techniques, are useful antibodies. A chimeric antibody is a molecule in which different portions are derived from different animal species, such as for example, those having a variable region derived from a murine monoclonal and human immunoglobulin constant regions. (See, e.g., U.S. Patent No. 4,816,567; and U.S. Patent No.4,816,397, which are incorporated herein by reference in their entirety.) Humanized antibodies are antibody molecules from non-human species having one or more complementarity determining regions (CDRs) from the non-human species and a framework region from a human immunoglobulin molecule. (See, e.g., U.S. Patent No. 5,585,089, which is incorporated herein by reference in its entirety.) Such chimeric and humanized monoclonal antibodies can be produced by recombinant DNA techniques known in the art, for example using methods described in International Publication No. WO 87/02671; European Patent Publication No.0184187; European Patent Publication No.0 171496; European Patent Publication No.0173494; International Publication No. WO 86/01533; U.S. Patent No.4,816,567; European Patent Publication No.012023; Berter et al., 1988, Science 240:1041-1043; Liu et al., 1987, Proc. Natl. Acad. Sci. USA 84:3439-3443; Liu et al., 1987, J. Immunol.139:3521-3526; Sun et al., 1987, Proc. Natl. Acad. Sci. USA 84:214-218; Nishimura et al., 1987, Cancer. Res.47:999-1005; Wood et al., 1985, Nature 314:446-449; and Shaw et al., 1988, J. Natl. Cancer Inst.80:1553-1559; Morrison, 1985, Science 229:1202-1207; Oi et al., 1986, BioTechniques 4:214; U.S. Patent No.5,225,539; Jones et al., 1986, Nature 321:552-525; Verhoeyan et al., 1988, Science 239:1534; and Beidler et al., 1988, J. Immunol.141:4053-4060; each of which is incorporated herein by reference in its entirety. [0062] In some embodiments, completely human antibodies in some instances (e.g., when immunogenicity to a non-human or chimeric antibody may occur) are more desirable and can be produced using transgenic mice that are incapable of expressing endogenous immunoglobulin heavy and light chains genes, but which can express human heavy and light chain genes. [0063] In some embodiments, antibodies include analogs and derivatives that are either modified, i.e., by the covalent attachment of any type of molecule as long as such covalent attachment permits the antibody to retain its antigen binding immunospecificity. For example, but not by way of limitation, derivatives and analogs of the antibodies include those that have been further modified, e.g., by glycosylation, acetylation, PEGylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to a cellular antibody unit or other protein, etc. Any of numerous chemical modifications can be carried out by known techniques including, but not limited to, specific chemical cleavage, acetylation, formylation, metabolic synthesis in the presence of tunicamycin, etc. Additionally, the analog or derivative can contain one or more unnatural amino acids. [0064] In some embodiments, antibodies can have modifications (e.g., substitutions, deletions or additions) in amino acid residues that interact with Fc receptors. In particular, antibodies can have modifications in amino acid residues identified as involved in the interaction between the anti-Fc domain and the FcRn receptor (see, e.g., International Publication No. WO 97/34631, which is incorporated herein by reference in its entirety). [0065] In some embodiments, antibodies of the present disclosure may be described or specified in terms of the particular CDRs they comprise. The precise amino acid sequence boundaries of a given CDR or FR can be readily determined using any of a number of well- known schemes, including those described by Kabat et al. (1991), “Sequences of Proteins of Immunological Interest,” 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD (“Kabat” numbering scheme); Al-Lazikani et al., (1997) JMB 273,927-948 (“Chothia” numbering scheme); MacCallum et al., J. Mol. Biol.262:732-745 (1996), “Antibody-antigen interactions: Contact analysis and binding site topography,” J. Mol. Biol. 262, 732-745.” (“Contact” numbering scheme); Lefranc MP et al., “IMGT unique numbering for immunoglobulin and T cell receptor variable domains and Ig superfamily V- like domains,” Dev Comp Immunol, 2003 Jan;27(1):55-77 (“IMGT” numbering scheme); Honegger A and Plückthun A, “Yet another numbering scheme for immunoglobulin variable domains: an automatic modeling and analysis tool,” J Mol Biol, 2001 Jun 8;309(3):657-70, (“Aho” numbering scheme); and Martin et al., “Modeling antibody hypervariable loops: a combined algorithm,” PNAS, 1989, 86(23):9268-9272, (“AbM” numbering scheme). The boundaries of a given CDR may vary depending on the scheme used for identification. In some embodiments, a “CDR” or “complementarity determining region,” or individual specified CDRs (e.g., CDR-H1, CDR-H2, CDR-H3), of a given antibody or region thereof (e.g., variable region thereof) should be understood to encompass a (or the specific) CDR as defined by any of the aforementioned schemes. For example, where it is stated that a particular CDR (e.g., a CDR-H3) contains the amino acid sequence of a corresponding CDR in a given VH or VL region amino acid sequence, it is understood that such a CDR has a sequence of the corresponding CDR (e.g., CDR-H3) within the variable region, as defined by any of the aforementioned schemes. The scheme for identification of a particular CDR or CDRs may be specified, such as the CDR as defined by the Kabat, Chothia, AbM or IMGT method. [0066] In some embodiments, antibodies immunospecific for a cancer cell antigen can be obtained commercially or produced by any method known to one of skill in the art such as, recombinant expression techniques. The nucleotide sequence encoding antibodies immunospecific for a cancer cell antigen can be obtained, e.g., from the GenBank database or a database like it, the literature publications, or by routine cloning and sequencing. [0067] In some embodiments, L is a known antibody for the treatment of a cancer. [0068] In some embodiments, L is a known antibody for the treatment of an autoimmune disease. [0069] In some embodiments, antibodies can bind to a receptor or a receptor complex expressed on an activated lymphocyte. The receptor or receptor complex can comprise an immunoglobulin gene superfamily member, a TNF receptor superfamily member, an integrin, a cytokine receptor, a chemokine receptor, a major histocompatibility protein, a lectin, or a complement control protein. [0070] In some embodiments, L is an antibody that specifically binds to CD19, CD30, CD33, CD70 or LIV-1. [0071] In some embodiments, L is an antibody that specifically binds to CD30. In some embodiments, the antibody is an anti-CD30 antibody, such as described in International Patent Publication No. WO 02/43661. In some embodiments, the anti-CD30 antibody is cAC10, which is described in International Patent Publication No. WO 02/43661. cAC10 is also known as brentuximab. In some embodiments, the anti-CD30 antibody comprises the CDRs of cAC10. In some embodiments, the CDRs are as defined by the Kabat numbering scheme. In some embodiments, the CDRs are as defined by the Chothia numbering scheme. In some embodiments, the CDRs are as defined by the IMGT numbering scheme. In some embodiments, the CDRs are as defined by the AbM numbering scheme. In some embodiments, the anti-CD30 antibody comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively. In some embodiments, the anti-CD30 antibody comprises a heavy chain variable region comprising an amino acid sequence that is at least 95%, at least 96%, at least 97%, at last 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 7 and a light chain variable region comprising an amino acid sequence that is at least 95% at least 96%, at least 97%, at last 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 8. In some embodiments, the anti-CD30 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 9 or SEQ ID NO: 10 and a light chain comprising the amino acid sequence of SEQ ID NO: 11. [0072] In some embodiments, L is an antibody that specifically binds to CD70. In some embodiments, the antibody is a h1F6 anti-CD70 antibody, which is described in International Patent Publication No. WO 2006/113909. In some embodiments, the anti-CD70 antibody comprises the CDRs of h1F6. In some embodiments, the CDRs are as defined by the Kabat numbering scheme. In some embodiments, the CDRs are as defined by the Chothia numbering scheme. In some embodiments, the CDRs are as defined by the IMGT numbering scheme. In some embodiments, the CDRs are as defined by the AbM numbering scheme. In some embodiments, L is an antibody that specifically binds to CD48. In some embodiments, the antibody is a hMEM102 anti-CD48 antibody, which is described in International Patent Publication No. WO 2016/149535. In some embodiments, the anti-CD48 antibody comprises the CDRs of hMEM102. In some embodiments, the CDRs are as defined by the Kabat numbering scheme. In some embodiments, the CDRs are as defined by the Chothia numbering scheme. In some embodiments, the CDRs are as defined by the IMGT numbering scheme. In some embodiments, the CDRs are as defined by the AbM numbering scheme.In some embodiments, L is an antibody that specifically binds to NTB-A. In some embodiments, the antibody is a h20F3 anti-NTB-A antibody, which is described in International Patent Publication No. WO 2017/004330. In some embodiments, the anti-NTB- A antibody comprises the CDRs of h20F3. In some embodiments, the CDRs are as defined by the Kabat numbering scheme. In some embodiments, the CDRs are as defined by the Chothia numbering scheme. In some embodiments, the CDRs are as defined by the IMGT numbering scheme. In some embodiments, the CDRs are as defined by the AbM numbering scheme. [0073] It is understood that each description of L can be combined with each description of y the same as if each and every combination were specifically and individually listed. For example, in some embodiments, y is 1 or 4; and L is an anti-CD30 antibody (e.g., a cAC10 anti-CD30 antibody). As another example, in some embodiments, y is 1; and L is an anti- CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively. [0074] In some embodiments, z is an integer from 2 to 12, from 2 to 11, from 2 to 10, from 2 to 9, from 2 to 8, from 2 to 7, from 2 to 6, from 2 to 5, from 2 to 4, from 2 to 3, from 3 to 12, from 3 to 11, from 3 to 10, from 3 to 9, from 3 to 8, from 3 to 7, from 3 to 6, from 3 to 5, from 3 to 4, from 4 to 12, from 4 to 11, from 4 to 10, from 4 to 9, from 4 to 8, from 4 to 7, from 4 to 6, from 4 to 5, from 5 to 12, from 5 to 11, from 5 to 10, from 5 to 9, from 5 to 8, from 5 to 7, from 5 to 6, from 6 to 12, from 6 to 11, from 6 to 10, from 6 to 9, from 6 to 8, from 6 to 7, from 7 to 12, from 7 to 11, from 7 to 10, from 7 to 9, from 7 to 8, from 8 to 12, from 8 to 11, from 8 to 10, from 8 to 9, from 9 to 12, from 9 to 11, from 9 to 10, from 10 to 12, from 10 to 11, or from 11 to 12. In some embodiments, z is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. In some embodiments, z is 2, 4, 6, 8, 10, or 12. In some embodiments, z is 2, 4, 8, or 12. In some embodiments, z is 2. In some embodiments, z is 3. In some embodiments, z is 4. In some embodiments, z is 5. In some embodiments, z is 6. In some embodiments, z is 7. In some embodiments, z is 8. In some embodiments, z is 9. In some embodiments, z is 10. In some embodiments, z is 11. In some embodiments, z is 12. It is understood that each description of z can be combined with each description of y and/or L the same as if each and every combination were specifically and individually listed. For example, in some embodiments, L is an anti-CD30 antibody (e.g., a cAC10 anti-CD30 antibody); and z is 2, 4, or 8. As another exmaple, in some embodiments, L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively; and z is 8. As another example, in some embodiments, y is 1 or 4; and z is 2, 4, or 8. As another example, in some embodiments, y is 1; and z is 8. As another example, in some embodiments, L is an anti- CD30 antibody (e.g., a cAC10 anti-CD30 antibody); y is 1 or 4; and z is 2, 4, or 8. As another example, in some embodiments, L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively; y is 1; and z is 8 [0075] In some embodiments, the subscript p represents the number of drug linker moieties on an antibody of an individual camptothecin conjugate and is an integer preferably ranging from 1 to 16, 1 to 12, 1 to 10, or 1 to 8. Individual camptothecin conjugate can be also be referred to as a camptothecin conjugate compound. In some embodiments, p is an integer from 1 to 16, from 1 to 15, from 1 to 14, from 1 to 13, from 1 to 12, from 1 to 11, from 1 to 10, from 1 to 9, from 1 to 8, from 1 to 7, from 1 to 6, from 1 to 5, from 1 to 4, from 1 to 3, from 1 to 2, from 2 to 16, from 2 to 15, from 2 to 14, from 2 to 13, from 2 to 12, from 2 to 11, from 2 to 10, from 2 to 9, from 2 to 8, from 2 to 7, from 2 to 6, from 2 to 5, from 2 to 4, from 2 to 3, from 3 to 16, from 3 to 15, from 3 to 14, from 3 to 13, from 3 to 12, from 3 to 11, from 3 to 10, from 3 to 9, from 3 to 8, from 3 to 7, from 3 to 6, from 3 to 5, from 3 to 4, from 4 to 16, from 4 to 15, from 4 to 14, from 4 to 13, from 4 to 12, from 4 to 11, from 4 to 10, from 4 to 9, from 4 to 8, from 4 to 7, from 4 to 6, from 4 to 5, from 5 to 16, from 5 to 15, from 5 to 14, from 5 to 13, from 5 to 12, from 5 to 11, from 5 to 10, from 5 to 9, from 5 to 8, from 5 to 7, from 5 to 6, from 6 to 16, from 6 to 15, from 6 to 14, from 6 to 13, from 6 to 12, from 6 to 11, from 6 to 10, from 6 to 9, from 6 to 8, from 6 to 7, from 7 to 16, from 7 to 15, from 7 to 14, from 7 to 13, from 7 to 12, from 7 to 11, from 7 to 10, from 7 to 9, from 7 to 8, from 8 to 16, from 8 to 15, from 8 to 14, from 8 to 13, from 8 to 12, from 8 to 11, from 8 to 10, from 8 to 9, from 9 to 16, from 9 to 15, from 9 to 14, from 9 to 13, from 9 to 12, from 9 to 11, from 9 to 10, from 10 to 16, from 10 to 15, from 10 to 14, from 10 to 13, from 10 to 12, from 10 to 11, from 11 to 16, from 11 to 15, from 11 to 14, from 11 to 13, from 11 to 12, from 12 to 16, from 12 to 15, from 12 to 14, from 12 to 13, from 13 to 16, from 13 to 15, from 13 to 14, from 14 to 16, from 14 to 15, or from 15 to 16. In some embodiments, p is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16. In some embodiments, p is 1. In some embodiments, p is 2. In some embodiments, p is 3. In some embodiments, p is 4. In some embodiments, p is 5. In some embodiments, p is 6. In some embodiments, p is 7. In some embodiments, p is 8. In some embodiments, p is 9. In some embodiments, p is 10. In some embodiments, p is 11. In some embodiments, p is 12. In some embodiments, p is 13. In some embodiments, p is 14. In some embodiments, p is 15. In some embodiments, p is 16. [0076] In one aspect, one group of embodiments contains a population of individual camptothecin conjugates substantially identical except for the number of drug-linkers bound to each antibody. The population can be described by the average number of drug-linkers bound to the antibody of the camptothecin conjugate (e.g., the Drug-Antibody Ratio (“DAR”)). In that group of embodiments, the average is a number ranging from 1 to about 16, 1 to about 12, 1 to about 10, or 1 to about 8, from 2 to about 16, 2 to about 12, 2 to about 10, or 2 to about 8. In some aspects, the average is about 2. In some aspects, the average is about 4. In some aspects, the average is about 8. In some aspects, the average is about 16. In some aspects, the average is 2. In some aspects, the average is 4. In some aspects, the average is 8. In some aspects, the average is 16. In some aspects, the population can be described by the drug loading of the predominate ADC in the composition. [0077] In some aspects, conjugation will be via the interchain disulfides and there will from 1 to about 8 drug-linkers conjugated to an antibody. In some aspects, conjugation will be via an introduced cysteine residue as well as interchain disulfides and there will be from 1 to 10 or 1 to 12 or 1 to 14 or 1 to 16 drug-linkers conjugated to an antibody. In some aspects, conjugation will be via an introduced cysteine residue and there will be 2 or 4 drug-linkers conjugated to an antibody. [0078] The formulations disclosed herein may contain a plurality of camptothecin conjugates. In some embodiments, each of the conjugates in the formulation is identical or substantially identical, however, the distribution of camptothecin drug-linkers on the antibody may vary as well as the drug loading. For example, the conjugation technology used to conjugate drug-linkers to antibodies can result in a formulation that is heterogeneous with respect to the distribution of drug linkers on the antibody within the formulation. In some embodiments, the loading of camptothecin drug linkers on each of the antibody molecules in a formulation is an integer that ranges from 1 to 14. Typically, the distribution results from the use of site-specific conjugation techniques and conjugation is due to an introduced cysteine residue. [0079] Within the formulation, there may also be a small percentage of unconjugated antibodies. The average number of drug-linkers per antibody in the formulation (i.e., average drug-load) is an important attribute as it determines the maximum amount of drug that can be delivered to the target cell. The average drug load can be 1, 2 or about 2, 3 or about 3, 4 or about 4, 5 or about 5, 6 or about 6, 7 or about 7, 8 or about 8, 9 or about 9, 10 or about 10, 11 or about 11, 12 or about 12, 13 or about 13, 14 or about 14, 15 or about 15, 16 or about 16. [0080] The average number of camptothecin drug-linkers per antibody in a preparation from a conjugation reaction (which may be referred to as the Drug-Antibody Ratio (“DAR”)) may be characterized by conventional means such as mass spectrometry, ELISA assay, HPLC (e.g., HIC). The quantitative distribution of camptothecin conjugates in terms of p may also be determined. In some instances, separation, purification, and characterization of homogeneous camptothecin conjugates may be achieved by means such as reverse phase HPLC or electrophoresis. [0081] In some embodiments, conjugation is via the interchain disulfides and there are from 1 to 8 drug linker moieties conjugated to an antibody. In some embodiments, conjugation is via an introduced cysteine residue as well as interchain disulfides and there will be from 1 to 10 or 1 to 12 or 1 to 14 or 1 to 16 drug linker moieties conjugated to an antibody. In some embodiments, conjugation is via an introduced cysteine residue and there are 2 or 4 drug linker moieties conjugated to an antibody. [0082] It is understood that each description of p can be combined with each description of L, y, and/or z the same as if each and every combination were specifically and individually listed. For example, in some embodiments, L is an anti-CD30 antibody (e.g., a cAC10 anti- CD30 antibody); z is 2, 4, or 8; and p is 8. As another exmaple, in some embodiments, L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR- L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively; z is 8; and p is 8. As another example, in some embodiments, L is an anti-CD30 antibody (e.g., a cAC10 anti-CD30 antibody); y is 1 or 4; z is 2, 4, or 8; and p is 8. As another example, in some embodiments, L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively; y is 1; z is 8; and p is 8. [0083] In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of between about 0.5 mg/mL and about 100 mg/mL, between about 0.5 mg/mL and about 90 mg/mL, between about 0.5 mg/mL and about 80 mg/mL, between about 0.5 mg/mL and about 70 mg/mL, between about 0.5 mg/mL and about 60 mg/mL, between about 0.5 mg/mL and about 50 mg/mL, between about 0.5 mg/mL and about 40 mg/mL, between about 0.5 mg/mL and about 30 mg/mL, between about 0.5 mg/mL and about 20 mg/mL, between about 0.5 mg/mL and about 10 mg/mL, between about 0.5 mg/mL and about 5 mg/mL, between about 10 mg/mL and about 100 mg/mL, between about 10 mg/mL and about 90 mg/mL, between about 10 mg/mL and about 80 mg/mL, between about 10 mg/mL and about 70 mg/mL, between about 10 mg/mL and about 60 mg/mL, between about 10 mg/mL and about 50 mg/mL, between about 10mg/mL and about 40 mg/mL, between about 10 mg/mL and about 30 mg/mL, between about 10 mg/mL and about 20 mg/mL, between about 20 mg/mL and about 100 mg/mL, between about 20 mg/mL and about 90 mg/mL, between about 20 mg/mL and about 80 mg/mL, between about 20 mg/mL and about 70 mg/mL, between about 20 mg/mL and about 60 mg/mL, between about 20 mg/mL and about 50 mg/mL, between about 20mg/mL and about 40 mg/mL, between about 20 mg/mL and about 30 mg/mL, between about 30 mg/mL and about 100 mg/mL, between about 30 mg/mL and about 90 mg/mL, between about 30 mg/mL and about 80 mg/mL, between about 30 mg/mL and about 70 mg/mL, between about 30 mg/mL and about 60 mg/mL, between about 30 mg/mL and about 50 mg/mL, between about 30mg/mL and about 40 mg/mL, between about 40 mg/mL and about 100 mg/mL, between about 40 mg/mL and about 90 mg/mL, between about 40 mg/mL and about 80 mg/mL, between about 40 mg/mL and about 70 mg/mL, between about 40 mg/mL and about 60 mg/mL, between about 40 mg/mL and about 50 mg/mL, between about 50 mg/mL and about 100 mg/mL, between about 50 mg/mL and about 90 mg/mL, between about 50 mg/mL and about 80 mg/mL, between about 50 mg/mL and about 70 mg/mL, between about 50 mg/mL and about 60 mg/mL, between about 60 mg/mL and about 100 mg/mL, between about 60 mg/mL and about 90 mg/mL, between about 60 mg/mL and about 80 mg/mL, between about 60 mg/mL and about 70 mg/mL, between about 70 mg/mL and about 100 mg/mL, between about 70 mg/mL and about 90 mg/mL, between about 70 mg/mL and about 80 mg/mL, between about 80 mg/mL and about 100 mg/mL, or between about 80 mg/mL and about 90 mg/mL. In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of about 0.5 mg/mL, about 5 mg/mL, about 10 mg/mL, about 15 mg/mL, about 20 mg/mL, about 25 mg/mL, about 30 mg/mL, about 35 mg/mL, about 40 mg/mL, about 45 mg/mL, about 50 mg/mL, about 55 mg/mL, about 60 mg/mL, about 65 mg/mL, about 70 mg/mL, about 75 mg/mL, about 80 mg/mL, about 85 mg/mL, about 90 mg/mL, about 95 mg/mL, or about 100 mg/mL. [0084] In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of between about 0.5 mg/mL and about 80 mg/mL. In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of about 10 mg/mL. In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of about 15 mg/mL. In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of about 20 mg/mL. In some embodiments, the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof has a concentration of about 25 mg/mL. [0085] In some embodiments, provided herein is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and a buffer containing an acetate salt, wherein the formulation has a pH of between about 4.0 and about 7.0. In some embodiments, the formulation contains a buffer that is sodium acetate. In some embodiments, the formulation has a pH of between about 4.0 and about 7.0, between about 4.0 and 6.6, between about 4.0 and about 6.2, between about 4.0 and about 5.8, between about 4.0 and about 5.4, between about 4.0 and about 5.0, between about 4.0 and about 4.8, between about 4.0 and about 4.6, between about 4.0 and about 4.4, between about 4.0 and about 4.2, between about 4.4 and about 7.0, between about 4.4 and 6.6, between about 4.4 and about 6.2, between about 4.4 and about 5.8, between about 4.4 and about 5.4, between about 4.4 and about 5.0, between about 4.4 and about 4.6, between 4.8 and about 7.0, between about 4.8 and 6.6, between about 4.8 and about 6.2, between about 4.8 and about 5.8, between about 4.8 and about 5.4, between about 4.8 and about 5.0, between about 5.2 and about 7.0, between about 5.2 and 6.6, between about 5.2 and about 6.2, between about 5.2 and about 5.8, between about 5.2 and about 5.4, between about 5.6 and about 7.0, between about 5.6 and 6.6, between about 5.6 and about 6.2, between about 5.6 and about 5.8, between about 6.0 and about 7.0, between about 6.0 and 6.6, between about 6.0 and about 6.2, between about 6.4 and about 7.0, between about 6.4 and 6.6, or between about 6.8 and about 7.0. In some embodiments, the formulation has a pH of about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, or about 7.0. [0086] In some embodiments, the formulation containing an acetate salt has a pH of between about 4.0 and about 4.8. In some embodiments, the formulation has a pH between about 4.0 and about 4.6. In some embodiments, the pH is about 4.0. In some embodiments, the pH is about 4.1. In some embodiments, the pH is about 4.2. In some embodiments, the pH is about 4.3. In some embodiments, the pH is about 4.4. In some embodiments, the pH is about 4.5. In some embodiments, the pH is about 4.6. In some embodiments, the pH is about 4.7. In some embodiments, the pH is about 4.8. [0087] In some embodiments, provided herein is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and a buffer containing glutamic acid, wherein the formulation has a pH of between about 4.0 and about 7.0. In some embodiments, the formulation has a pH of between about 4.0 and about 7.0, between about 4.0 and 6.6, between about 4.0 and about 6.2, between about 4.0 and about 5.8, between about 4.0 and about 5.4, between about 4.0 and about 5.0, between about 4.0 and about 4.8, between about 4.0 and about 4.6, between about 4.0 and about 4.4, between about 4.0 and about 4.2, between about 4.4 and about 7.0, between about 4.4 and 6.6, between about 4.4 and about 6.2, between about 4.4 and about 5.8, between about 4.4 and about 5.4, between about 4.4 and about 5.0, between about 4.4 and about 4.8, between about 4.4 and about 4.6, between 4.8 and about 7.0, between about 4.8 and 6.6, between about 4.8 and about 6.2, between about 4.8 and about 5.8, between about 4.8 and about 5.4, between about 4.8 and about 5.0, between about 5.2 and about 7.0, between about 5.2 and 6.6, between about 5.2 and about 6.2, between about 5.2 and about 5.8, between about 5.2 and about 5.4, between about 5.6 and about 7.0, between about 5.6 and 6.6, between about 5.6 and about 6.2, between about 5.6 and about 5.8, between about 6.0 and about 7.0, between about 6.0 and 6.6, between about 6.0 and about 6.2, between about 6.4 and about 7.0, between about 6.4 and 6.6, or between about 6.8 and about 7.0. In some embodiments, the formulation has a pH of about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, or about 7.0. [0088] In some embodiments, the formulation containing glutamic acid has a pH between about 4.0 and about 4.8. In some embodiments, the formulation has a pH between about 4.4 and about 4.8. In some embodiments, the pH is about 4.0. In some embodiments, the pH is about 4.1. In some embodiments, the pH is about 4.2. In some embodiments, the pH is about 4.3. In some embodiments, the pH is about 4.4. In some embodiments, the pH is about 4.5. In some embodiments, the pH is about 4.6. In some embodiments, the pH is about 4.7. In some embodiments, the pH is about 4.8. [0089] In some embodiments, provided herein is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and a buffer containing histidine, wherein the formulation has a pH of between about 4.8 and about 7.0. In some embodiments, the formulation has a pH of between 4.8 and about 7.0, between about 4.8 and about 6.6, between about 4.8 and about 6.2, between about 4.8 and about 5.8, between about 4.8 and about 5.6, between about 4.8 and about 5.4, between about 4.8 and about 5.2, between about 4.8 and about 5.0, between 5.0 and about 7.0, between about 5.0 and about 6.6, between about 5.0 and about 6.2, between about 5.0 and about 5.8, between about 5.0 and about 5.6, between about 5.0 and about 5.5, between about 5.0 and about 5.4, between about 5.0 and about 5.2, between about 5.2 and about 7.0, between about 5.2 and 6.6, between about 5.2 and about 6.2, between about 5.2 and about 5.8, between about 5.2 and about 5.4, between about 5.6 and about 7.0, between about 5.6 and 6.6, between about 5.6 and about 6.2, between about 5.6 and about 5.8, between about 6.0 and about 7.0, between about 6.0 and 6.6, between about 6.0 and about 6.2, between about 6.4 and about 7.0, between about 6.4 and 6.6, or between about 6.8 and about 7.0. In some embodiments, the formulation has a pH of about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, or about 7.0. [0090] In some embodiments, the formulation containing histidine has a pH between about 4.8 and about 5.6. In some embodiments, the formulation has a pH between about 5.0 and about 5.5. In some embodiments, the pH is about 4.8. In some embodiments, the pH is about 4.9. In some embodiments, the pH is about 5.0. In some embodiments, the pH is about 5.1. In some embodiments, the pH is about 5.2. In some embodiments, the pH is about 5.3. In some embodiments, the pH is about 5.4. In some embodiments, the pH is about 5.5. In some embodiments, the pH is about 5.6. [0091] In some embodiments, provided herein is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and a buffer containing a sulfonic acid, wherein the formulation has a pH of between about 5.0 and about 7.0. As used herein, a sulfonic acid, refers to a compound having a – S(=O)₂OH moiety. Examples of sulfonic acids include, but are not limited to, 2-(N- morpholino)ethanesulfonic acid (MES), benzenesulfonic acid, 3-(N- morpholino)propanesulfonic acid (MOPS), methanesulfonic acid, N-cyclohexyl-3- aminopropanesulfonic acid (CAPS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), polystyrene sulfonic acid, N-(2-Hydroxyethyl)piperazine-N'-(4-butanesulfonic acid) (HEPBS), or 1,4-piperazinediethanesulfonic acid (PIPES). In some embodiments, the sulfonic acid is HEPES, MES, or MOPS. In some embodiments, the sulfonic acid is MES. In some embodiments, the sulfonic acid is benzenesulfonic acid. In some embodiments, the sulfonic acid is MOPS. In some embodiments, the sulfonic acid is methanesulfonic acid. In some embodiments, the sulfonic acid is CAPS. In some embodiments, the sulfonic acid is HEPES. In some embodiments, the sulfonic acid is polystyrene sulfonic acid. In some embodiments, the sulfonic acid is HEPBS. In some embodiments, the sulfonic acid is PIPES. [0092] In some embodiments, the formulation containing a sulfonic acid buffer has a pH of between 5.5 and about 7.0, between about 5.5 and about 6.5, between about 5.5 and about 6.0, between 6.0 and about 7.0, between about 6.0 and about 6.5, or between about 6.5 and about 7.0. In some embodiments, the formulation has a pH between about 6.0 and about 7.0. In some embodiments, the pH is about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, or about 7.0. [0093] In some embodiments, the formulation containing a sulfonic acid buffer has a pH of between about 6.0 and about 7.0. In some embodiments, the pH is about 6.0. In some embodiments, the pH is about 6.1. In some embodiments, the pH is about 6.2. In some embodiments, the pH is about 6.3. In some embodiments, the pH is about 6.4. In some embodiments, the pH is about 6.5. In some embodiments, the pH is about 6.6. In some embodiments, the pH is about 6.7. In some embodiments, the pH is about 6.8. In some embodiments, the pH is about 6.9. In some embodiments, the pH is about 7.0. In some embodiments, the sulfonic acid is MES and the pH is about 6.0. In some embodiments, the sulfonic acid is MES and the pH is about 5.5. In some embodiments, the sulfonic acid is MOPS and the pH is about 6.2. [0094] In some embodiments, the buffer (e.g., acetate salt, glutamic acid, histidine, or sulfonic acid) has a concentration of between about 1 mM and about 60 mM, between about 5 mM and about 60 mM, between about 10 mM and about 60 mM, about 15 mM and about 60 mM, between about 20 mM and about 60 mM, about 25 mM and about 60 mM, between about 30 mM and about 60 mM, about 35 mM and about 60 mM, between about 40 mM and about 60 mM, about 45 mM and about 60 mM, between about 50 mM and about 60 mM, about 55 mM and about 60 mM, between about 1 mM and about 50 mM, between about 5 mM and about 50 mM, between about 10 mM and about 50 mM, about 15 mM and about 50 mM, between about 20 mM and about 50 mM, about 25 mM and about 50 mM, between about 30 mM and about 50 mM, about 35 mM and about 50 mM, between about 40 mM and about 50 mM, about 45 mM and about 55 mM, between about 1 mM and about 40 mM, between about 5 mM and about 40 mM, between about 10 mM and about 40 mM, about 15 mM and about 40 mM, between about 20 mM and about 40 mM, about 25 mM and about 40 mM, between about 30 mM and about 40 mM, about 35 mM and about 40 mM, between about 1 mM and about 30 mM, between about 5 mM and about 30 mM, between about 10 mM and about 30 mM, about 15 mM and about 30 mM, between about 20 mM and about 30 mM, about 25 mM and about 30 mM, between about 1 mM and about 20 mM, between about 5 mM and about 20 mM, between about 10 mM and about 20 mM, about 15 mM and about 20 mM, between about 1 mM and about 10 mM, or between about 5 mM and about 10 mM. In some embodiments, the buffer (e.g., acetate salt, glutamic acid, histidine, or sulfonic acid) has a concentration of about 1 mM, about 5 mM, about 10 mM, about 15 mM, about 20 mM, about 25 mM, about 30 mM, about 35 mM, about 40 mM, about 45 mM, about 50 mM, about 55 mM, or about 60 mM. [0095] In some embodiments, the buffer (e.g., acetate salt, glutamic acid, histidine, or sulfonic acid) has a concentration of between about 15 mM and about 50 mM. In some embodiments, the buffer has a concentration of about 15 mM. In some embodiments, the buffer has a concentration of about 20 mM. In some embodiments, the buffer has a concentration of about 25 mM. [0096] It is understood that each and every description of the buffer, pH, and/or concentration of the buffer may be combined with each and every description of the camptothecin conjugate or a pharmaceutically acceptable salt thereof and/or the concentration of the camptothecin conjugate or a pharmaceutically acceptable salt thereof the same as if each and every combination were specifically and individually listed. For example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody, z is 8, and p is 8; and a buffer containing a acetate salt, wherein the formulation has a pH of between about 4.0 and 4.8. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively, z is 8, and p is 8; and a buffer containing sodium acetate, wherein the formulation has a pH of about 4.5. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody, z is 8, and p is 8; and a buffer containing glutamic acid, wherein the formulation has a pH of between about 4.0 and 4.8. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively, z is 8, and p is 8; and a buffer containing glutamic acid, wherein the formulation has a pH of about 4.5. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody, z is 8, and p is 8; and a buffer containing histidine, wherein formulation has a pH of between about 4.8 and about 5.6. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively, z is 8, and p is 8; and a buffer containing histidine, wherein the formulation has a pH of about 5.5. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody, z is 8, and p is 8; and a buffer containing a sulfonic acid, wherein the formulation has a pH of between about 6.0 and about 7.0. As another example, in some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, wherein L is an anti-CD30 antibody comprising CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively, z is 8, and p is 8; and a buffer that is MES, wherein the formulation has a pH of about 6.0. [0097] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof further contains an excipient. In some embodiments, the excipient is a stabilizer. As used herein, the term "stabilizer" refers an excipient capable of protecting an active ingredient from aggregation or physical or chemical degradation in an aqueous state, functioning as a lyoprotectant (i.e., protecting the active ingredient during drying), and/or functioning as a cryoprotectant (i.e., protecting the active ingredient during freezing). Examples of stabilizers include, but are not limited to, sugar (e.g., sucrose, trehalose, mannose, maltose, lactose, glucose, raffinose, cellobiose, gentiobiose, isomaltose, arabinose, glucosamine, or fructose), sugar alcohol (e.g., mannitol or sorbitol), amino acid (e.g., aspartic acid, glycine, arginine, or arginine-glutamic acid), cyclodextrin (e.g., sulfobutylether-beta-cyclodextrin (SBECD), beta-cyclodextrin, or gamma-cyclodextrin), sulfate salt, hydrosulfite salt, poly(lactic-co-glycolic acid (PLGA), and polyethylene glycol (e.g., PEG 200, PEG 400, PEG 600, PEG 1000, PEG 1500, or PEG 2000). It is understood that other forms of the excipients, such as salts, solvates, or hydrates, are also contemplated. In some embodiment, the formulation further contains a stabilizer, wherein the stabilizer is sucrose or trehalose. In some embodiment, the formulation further contains a stabilizer, wherein the stabilizer is trehalose (e.g., trehalose dihydrate). In some embodiments, the stabilizer such as trehalose has low hygroscopicity, low chemical reactivity, and high glass transition. In some embodiments, the stabilizer such as trehalose is non-acid labile. In some embodiments, the stabilizer such as trehalose can work in a wide pH range. In some embodiments, the stabilizer such as trehalose functions as a lyoprotectant. In some embodiments, the stabilizer such as trehalose functions as a cryoprotectant. In some embodiments, the stabilizer such as trehalose can protect protein structure, provide bulk to the lyophilization cake, and prevent shrinkage of the lyophilization cake. [0098] In some embodiments, the concentration of the stabilizer is between about 0.1% (w/v) and about 10% (w/v), between about 0.1% (w/v) and about 9% (w/v), between about 0.1% (w/v) and about 8% (w/v), between about 0.1% (w/v) and about 7% (w/v), between about 0.1% (w/v) and about 6% (w/v), between about 0.1% (w/v) and about 5% (w/v), between about 0.1% (w/v) and about 4% (w/v), between about 0.1% (w/v) and about 3% (w/v), between about 0.1% (w/v) and about 2% (w/v), between about 0.1% (w/v) and about 1% (w/v), between about 1% (w/v) and about 10% (w/v), between about 1% (w/v) and about 9% (w/v), between about 1% (w/v) and about 8% (w/v), between about 1% (w/v) and about 7% (w/v), between about 1% (w/v) and about 6% (w/v), between about 1% (w/v) and about 5% (w/v), between about 1% (w/v) and about 4% (w/v), between about 1% (w/v) and about 3% (w/v), between about 1% (w/v) and about 2% (w/v), between about 2% (w/v) and about 10% (w/v), between about 2% (w/v) and about 9% (w/v), between about 2% (w/v) and about 8% (w/v), between about 2% (w/v) and about 7% (w/v), between about 2% (w/v) and about 6% (w/v), between about 1% (w/v) and about 5% (w/v), between about 2% (w/v) and about 4% (w/v), between about 2% (w/v) and about 3% (w/v), between about 3% (w/v) and about 10% (w/v), between about 3% (w/v) and about 9% (w/v), between about 3% (w/v) and about 8% (w/v), between about 3% (w/v) and about 7% (w/v), between about 3% (w/v) and about 6% (w/v), between about 3% (w/v) and about 5% (w/v), between about 3% (w/v) and about 4% (w/v), between about 4% (w/v) and about 10% (w/v), between about 4% (w/v) and about 9% (w/v), between about 4% (w/v) and about 8% (w/v), between about 4% (w/v) and about 7% (w/v), between about 4% (w/v) and about 6% (w/v), between about 4% (w/v) and about 5% (w/v), between about 5% (w/v) and about 10% (w/v), between about 5% (w/v) and about 9% (w/v), between about 5% (w/v) and about 8% (w/v), between about 5% (w/v) and about 7% (w/v), between about 5% (w/v) and about 6% (w/v), between about 6% (w/v) and about 10% (w/v), between about 6% (w/v) and about 9% (w/v), between about 6% (w/v) and about 8% (w/v), between about 6% (w/v) and about 7% (w/v), between about 7% (w/v) and about 10% (w/v), between about 7% (w/v) and about 9% (w/v), between about 7% (w/v) and about 8% (w/v), between about 8% (w/v) and about 10% (w/v), between about 8% (w/v) and about 9% (w/v), or between about 9% (w/v) and about 10% (w/v).. In some embodiments, the concentration of the stabilizer is about 0.1% (w/v), about 1% (w/v), about 1.5% (w/v), about 2% (w/v), about 2.5% (w/v), about 3% (w/v), about 3.5% (w/v), about 4% (w/v), about 4.5% (w/v), about 5% (w/v), about 5.5% (w/v), about 6% (w/v), about 6.5% (w/v), about 7% (w/v), about 7.5% (w/v), about 8% (w/v), about 8.5% (w/v), about 9% (w/v), about 9.5% (w/v), or about 10% (w/v). [0099] In some embodiments, the excipient is a surfactant. As used herein, the term "surfactant" refers an excipient capable of reducing surface tension and preventing surface- induced aggregation. Examples of surfactants include, but are not limited to, Triton X-100, poloxamer (e.g., Pluronic F-68 or Pluronic F-127), and polysorbate (e.g., PS20 or PS80). In some embodiments, the formulation further contains a surfactant, wherein the surfactant is PS80. It is understood that other forms of the excipients, such as salts, solvates, or hydrates, are also contemplated. In some embodiments, the excipient such as PS80 can function as a solubilizer. In some embodiments, the excipient such as PS80 can protect the active ingredient against freeze-thaw, agitation, and thermal stresses. [0100] In some embodiments, the concentration of the surfactant is between about 0.001% (w/v) and about 0.1% (w/v), between about 0.001% (w/v) and about 0.05% (w/v), between about 0.001% (w/v) and about 0.01% (w/v), between about 0.001% (w/v) and about 0.005% (w/v), between about 0.005% (w/v) and about 0.1% (w/v), between about 0.005% (w/v) and about 0.05% (w/v), between about 0.005% (w/v) and about 0.01% (w/v), between about 0.01% (w/v) and about 0.1% (w/v), between about 0.01% (w/v) and about 0.05% (w/v), or between about 0.05% (w/v) and about 0.1% (w/v). In some embodiments, the concentration of the surfactant is about 0.001% (w/v), 0.005% (w/v), 0.01% (w/v), 0.02% (w/v), 0.03% (w/v), 0.04% (w/v), 0.05% (w/v), 0.06% (w/v), 0.07% (w/v), 0.08% (w/v), 0.09% (w/v), or 0.1% (w/v). [0101] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof further contains one or more excipients selected from the group consisting of arginine-glutamic acid, arginine, aspartic acid, sulfobutylether-beta-cyclodextrin (SBECD), polyethylene glycol, sodium sulfate, sodium hydrosulfite, trimethyl glycine, Triton X-100, Pluronic F-68, Pluronic F-127, polysorbate 80 (PS80), polysorbate 20 (PS20), poly(lactic-co-glycolic acid (PLGA), beta- cyclodextrin, gamma-cyclodextrin, sucrose, and trehalose. [0102] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof contains trehalose (e.g., trehalose dihydrate) at a concentration of between about 5% (w/v) and about 10% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of between about 6% (w/v) and about 8% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of about 7% (w/v). In some embodiments, the formulation contains PS80 at a concentration of between about 0.01% (w/v) and about 0.05% (w/v). In some embodiments, the formulation contains PS80 at a concentration of about 0.02% (w/v). In some embodiments, the formulation contains PS80 at a concentration of about 0.03% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of between about 5% (w/v) and about 10% (w/v) and PS80 at a concentration of between about 0.01% (w/v) and about 0.05% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of about 7% (w/v) and PS80 at a concentration of about 0.02% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of about 3.5% (w/v) and PS80 at a concentration of about 0.02% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of about 7% (w/v) and PS80 at a concentration of about 0.03% (w/v). In some embodiments, the formulation contains trehalose (e.g., trehalose dihydrate) at a concentration of about 3.5% (w/v) and PS80 at a concentration of about 0.03% (w/v). [0103] It is understood that each and every description of the excipient and/or its concentration may be combined with each and every description of the buffer, pH, and/or concentration of the buffer, the camptothecin conjugate or a pharmaceutically acceptable salt thereof, and/or the concentration of the camptothecin conjugate or a pharmaceutically acceptable salt thereof the same as if each and every combination were specifically and individually listed. As an example, in some embodiments, the formulation contains about 20mM Histidine, about 100mM Arginine/Glutamic acid, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 5.5. As another example, in some embodiments, the formulation contains about 20 mM MES, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 5.5. As another example, in some embodiments, the formulation contains about 20 mM Histidine, about 6% (w/v) SBECD, about 3.5% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 6. As another example, in some embodiments, the formulation contains about 20 mM Glutamic acid, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 4.5. As another example, in some embodiments, the formulation contains about 20 mM acetic acid, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 4.5. As another example, in some embodiments, the formulation contains about 20 mM aspartic acid, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 4.5. As another example, in some embodiments, the formulation contains about 20 mM Histidine, about 5% (w/v) PEG400, about 7% (w/v) trehalose dihydrate, and about 0.03% (w/v) PS80, and has a pH of about 5. [0104] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is an aqueous formulation. In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is a lyophilized formulation prepared by lyophilization of the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof as disclosed herein. [0105] In some embodiments, provided is a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof prepared by reconstituting a lyophilized formulation disclosed herein (i.e., a reconstituted formulation). A reconstituted formulation may be prepared by dissolving a lyophilized formulation in a suitable diluent such as sterile water or saline. [0106] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is stable for 6, 12, 18, or 24 months at 25°C. In some embodiments, the formulation is stable for 6, 12, 18, or 24 months at 5°C. [0107] In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is a pharmaceutically acceptable formulation. In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is a sterile formulation. In some embodiments, the formulation is a pharmaceutically acceptable lyophilized formulation. In some embodiments, the formulation is a sterile lyophilized formulation. In some embodiments, the formulation is a pharmaceutically acceptable reconstituted formulation. In some embodiments, the formulation is a sterile reconstituted formulation. [0108] In some embodiments, the formulation described herein further contains another therapeutic agent known for the treatment of cancer. In some embodiments, the formulation described herein further contains another therapeutic agent known for the treatment of an autoimmune disease. Methods of Preparation [0109] In another aspect, provided is a method of preparing a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, the method including combining a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof with a buffer disclosed herein. In some embodiments, the method further includes combining the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof and the buffer with an excipient disclosed herein. It is understood that the camptothecin conjugate or a pharmaceutically acceptable salt thereof, the concentration of the camptothecin conjugate or a pharmaceutically acceptable salt thereof, the buffer, the pH, the concentration of the buffer, the excipient, and/or the concentration of the excipient disclosed herein are applicable to the method of preparation where appropriate. In some embodiments, the formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is prepared by buffer exchange. In some embodiments, the formulation is prepared by buffer exchange using a formulation containing sodium acetate. [0110] In another aspect, provided is a method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC) or (I), the method including formulating the camptothecin conjugate in a solution that has the buffer, pH, and/or excipient as disclosed herein. The extent of reduction may be determined by visual examination, cloud-point measurements, or temperature quenching and centrifugation. In some embodiments, other techniques such as chromatography and spectroscopy that can quantify ADCs may also be used. It is understood that the camptothecin conjugate or a pharmaceutically acceptable salt thereof, the concentration of the camptothecin conjugate or a pharmaceutically acceptable salt thereof, the buffer, the pH, the concentration of the buffer, the excipient, and/or the concentration of the excipient disclosed are applicable to the method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate where appropriate. [0111] In another aspect, provided herein is a method of preparing a lyophilized form of formulation of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof, the method including lyophilizing the formulation of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof as disclosed herein. Lyophilization may be carried out using techniques common in the art. See, e.g., Tang et al., Pharm Res.21: 191-200, (2004) and Chang et al, Pharm Res.13:243-9 (1996). A lyophilization cycle is, in some embodiments, composed of three steps: freezing, primary drying, and secondary drying. See, e.g., A. P. Mackenzie, Phil Trans R Soc London, Ser B, Biol 278: 167 (1977). In the freezing step, the solution is cooled to initiate ice formation. Furthermore, this step induces the crystallization of the bulking agent. The ice sublimes in the primary drying stage, which is conducted by reducing chamber pressure below the vapor pressure of the ice, using a vacuum and introducing heat to promote sublimation. Finally, adsorbed or bound water is removed at the secondary drying stage under reduced chamber pressure and at an elevated shelf temperature. Methods of Use [0112] The formulations described herein are useful for medical therapy. In some embodiments of any of the uses provided herein, the subject or patient is administered a pharmaceutically acceptable formulation (e.g., a sterile formulation) provided herein. In some embodiments of any of the uses provided herein, the subject or patient is administered a pharmaceutically acceptable reconstituted formulation (e.g., a sterile reconstituted formulation). Treatment of Cancer [0113] The formulations described herein are useful for inhibiting the multiplication of a tumor cell or cancer cell, causing apoptosis in a tumor or cancer cell, or for treating cancer in a patient. Accordingly, in another aspect, provided herein is a method of treating cancer in a subject in need thereof, the method including administering to the subject a therapeutically effective amount of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof as disclosed herein. In another aspect, provided is a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt for use in the treatment of cancer. In another aspect, provided is use of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of cancer. [0114] In some embodiments, the antibody of the camptothecin conjugate of Formula (IC) or (I) binds to the tumor cell or cancer cell. [0115] In some embodiments, the antibody of the camptothecin conjugate of Formula (IC) or (I) binds to a tumor cell or cancer cell antigen which is on the surface of the tumor cell or cancer cell. [0116] In some embodiments, the antibody of the camptothecin conjugate of Formula (IC) or (I) binds to a tumor cell or cancer cell antigen which is an extracellular matrix protein associated with the tumor cell or cancer cell. [0117] The specificity of the antibody of the camptothecin conjugate of Formula (IC) or (I) for a particular tumor cell or cancer cell can be important for determining the tumors or cancers that are most effectively treated. For example, camptothecin conjugates that target a cancer cell antigen present in hematopoietic cancers can be useful treating hematologic malignancies (e.g., anti-CD30, anti-CD70, anti-CD19, anti-CD33 antibody can be useful for treating hematologic malignancies). Camptothecin conjugates that target a cancer cell antigen present on solid tumors can be useful treating such solid tumors. [0118] Cancers that can be treated with the pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof include, but are not limited to, hematopoietic cancers such as, for example, lymphomas (Hodgkin Lymphoma and Non-Hodgkin Lymphomas) and leukemias and solid tumors. Examples of hematopoietic cancers include, but are not limited to, follicular lymphoma, anaplastic large cell lymphoma, mantle cell lymphoma, acute myeloblastic leukemia, chronic myelocytic leukemia, chronic lymphocytic leukemia, diffuse large B cell lymphoma, and multiple myeloma. Examples of solid tumors include, but are not limited to, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing’s tumor, leiomyosarcoma, rhabdomyosarcoma, colon cancer, colorectal cancer, kidney cancer, pancreatic cancer, bone cancer, breast cancer, ovarian cancer, prostate cancer, esophageal cancer, stomach cancer, oral cancer, nasal cancer, throat cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms’ tumor, cervical cancer, uterine cancer, testicular cancer, small cell lung carcinoma, bladder carcinoma, lung cancer, epithelial carcinoma, glioma, glioblastoma multiforme, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, skin cancer, melanoma, neuroblastoma, and retinoblastoma. [0119] In some embodiments, the cancers treated are any one of the above-listed lymphomas and leukemias. [0120] In another aspect, provided herein is a method for treating cancer, the method including administering to a patient in need thereof a therapeutically effective amount of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and another therapeutic agent known for the treatment of cancer. Multi-Modality Therapy for Cancer [0121] In another aspect, provided herein is a method for treating cancer, the method including administering to a patient in need thereof a therapeutically effective amount of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and a chemotherapeutic agent. In some embodiments, the chemotherapeutic agent is that with which treatment of the cancer has not been found to be refractory. In some embodiments, the chemotherapeutic agent is that with which the treatment of cancer has been found to be refractory. The pharmaceutically acceptable formulation of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof can be administered to a patient that has also undergone surgery as treatment for the cancer. [0122] In some embodiments, the patient also receives an additional treatment, such as radiation therapy. In some embodiments, the pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof is administered concurrently with the chemotherapeutic agent or with radiation therapy. In some embodiments, the chemotherapeutic agent or radiation therapy is administered prior or subsequent to administration of the pharmaceutically acceptable formulation of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof. [0123] A chemotherapeutic agent can be administered over a series of sessions. Any one or a combination of the chemotherapeutic agents, such a standard of care chemotherapeutic agent(s), can be administered. [0124] Additionally, in some embodiments, methods of treatment of cancer with the pharmaceutically acceptable formulation containing the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof are provided as an alternative to chemotherapy or radiation therapy where the chemotherapy or the radiation therapy has proven or can prove too toxic, e.g., results in unacceptable or unbearable side effects, for the subject being treated. The patient being treated can, optionally, be treated with another cancer treatment such as surgery, radiation therapy or chemotherapy, depending on which treatment is found to be acceptable or bearable. Treatment of Autoimmune Diseases [0125] The formulations disclosed herein are useful for killing or inhibiting the unwanted replication of cells that produces an autoimmune disease or for treating an autoimmune disease. In another aspect, provided herein is a method for treating an autoimmune disease, the method including administering to a patient in need thereof a therapeutically effective amount of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein. In another aspect, provided is a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof for use in the treatment of an autoimmune disease. In another aspect, provided is use of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of an autoimmune disease. [0126] In some embodiments, the antibody of the camptothecin conjugate of Formula (IC) or (I) disclosed herein binds to an autoimmune antigen. In one aspect, the antigen is on the surface of a cell involved in an autoimmune condition. [0127] In some embodiments, the antibody of the camptothecin conjugate of Formula (IC) or (I) disclosed herein binds to activated lymphocytes that are associated with the autoimmune disease state. [0128] In a further embodiment, the pharmaceutically acceptable formulation of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof kills or inhibits the multiplication of cells that produce an autoimmune antibody associated with a particular autoimmune disease. [0129] Particular types of autoimmune diseases that can be treated with the pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein include, but are not limited to, Th2 lymphocyte related disorders (e.g., atopic dermatitis, atopic asthma, rhinoconjunctivitis, allergic rhinitis, Omenn’s syndrome, systemic sclerosis, and graft versus host disease); Th1 lymphocyte-related disorders (e.g., rheumatoid arthritis, multiple sclerosis, psoriasis, Sjorgren’s syndrome, Hashimoto’s thyroiditis, Grave’s disease, primary biliary cirrhosis, Wegener’s granulomatosis, and tuberculosis); and activated B lymphocyte-related disorders (e.g., systemic lupus erythematosus, Goodpasture’s syndrome, rheumatoid arthritis, and type I diabetes). Multi-Drug Therapy of Autoimmune Diseases [0130] In another aspect, provided herein is a method for treating an autoimmune disease, the method including administering to a patient in need thereof a therapeutically effective amount of a pharmaceutically acceptable formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein and another therapeutic agent known for the treatment of the autoimmune disease. Methods of Administration [0131] The formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof disclosed herein may be administered parenterally. Parenteral administration includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In some embodiments, the formulation is administered subcutaneously. In some embodiments, the formulation is administered intravenously. Administration can be by any convenient route, for example by infusion or bolus injection. [0132] The amount of the formulation that is effective in the treatment of a particular disorder or condition will depend on the nature of the disorder or condition, and can be determined by standard clinical techniques. In addition, in vitro or in vivo assays can optionally be employed to help identify optimal dosage ranges. The precise dose to be employed will also depend on the route of administration, and the seriousness of the disease or disorder, and should be decided according to the judgment of the practitioner and each patient’s circumstances. [0133] For intravenous administration, the formulation can contain from about 0.01 to about 100 mg of a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof per kg of the animal’s body weight. In some embodiments, the formulation can include from about 1 to about 100 mg of the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof per kg of the animal’s body weight. In some embodiments, the amount administered will be in the range from about 0.1 to about 25 mg/kg of body weight of a compound. Depending on the drug used, the dosage can be even lower, for example, 1.0 μg/kg to 5.0 mg/kg, 4.0 mg/kg, 3.0 mg/kg, 2.0 mg/kg or 1.0 mg/kg, or 1.0 μg/kg to 500.0 μg/kg of the subject’s body weight. [0134] Generally, the dosage of the camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof administered to a patient is typically about 0.01 mg/kg to about 100 mg/kg of the subject’s body weight or from 1.0 μg/kg to 5.0 mg/kg of the subject’s body weight. In some embodiments, the dosage administered to a patient is between about 0.01 mg/kg to about 15 mg/kg of the subject’s body weight. In some embodiments, the dosage administered to a patient is between about 0.1 mg/kg and about 15 mg/kg of the subject’s body weight. In some embodiments, the dosage administered to a patient is between about 0.1 mg/kg and about 20 mg/kg of the subject’s body weight. In some embodiments, the dosage administered is between about 0.1 mg/kg to about 5 mg/kg or about 0.1 mg/kg to about 10 mg/kg of the subject’s body weight. In some embodiments, the dosage administered is between about 1 mg/kg to about 15 mg/kg of the subject’s body weight. In some embodiments, the dosage administered is between about 1 mg/kg to about 10 mg/kg of the subject’s body weight. In some embodiments, the dosage administered is between about 0.1 to 4 mg/kg, even more preferably 0.1 to 3.2 mg/kg, or even more preferably 0.1 to 2.7 mg/kg of the subject’s body weight over a treatment cycle. Kits [0135] In another aspect, provided is a kit containing a formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof as disclosed herein. In some embodiments, the kit contains a pre-lyophilized formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the kit contains a lyophilized formulation containing a camptothecin conjugate of Formula (IC) or (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the formulation is packaged in a manner which facilitates its use for administration to subjects. In some embodiments, the formulation is packaged in a container such as a sealed bottle or vessel. In some embodiments, the kit contains a first container having a lyophilized formulation and a second container having a pharmaceutically acceptable reconstitution solution for the formulation. In some embodiments, the formulation is packaged in a unit dosage form. In some embodiments, the kit further contains a device suitable for administering the formulation according to a specific route of administration. In some embodiments, the kit further contains a label that describes use of the formulation (e.g., according to any of the uses described herein). [0136] Exemplary embodiments are provided below. Embodiment 1. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising an acetate salt, wherein the formulation has a pH of between about 4.0 and about 4.8. Embodiment 2. The formulation of embodiment 1, wherein the buffer is sodium acetate. Embodiment 3. The formulation of embodiment 1 or 2, wherein the pH is about 4.5. Embodiment 4. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising glutamic acid, wherein the formulation has a pH of between about 4.0 and about 4.8. Embodiment 5. The formulation of embodiment 4, wherein the pH is about 4.5. Embodiment 6. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising histidine, wherein the formulation has a pH of between about 4.8 and about 5.6. Embodiment 7. The formulation of embodiment 6, wherein the pH is about 5.5. Embodiment 8. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising a sulfonic acid, wherein the formulation has a pH of between about 6.0 and about 7.0. Embodiment 9. The formulation of embodiment 8, wherein the buffer is 2-(N- morpholino)ethanesulfonic acid (MES), benzenesulfonic acid, 3-(N- morpholino)propanesulfonic acid (MOPS), methanesulfonic acid, N-cyclohexyl-3- aminopropanesulfonic acid (CAPS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), polystyrene sulfonic acid, N-(2-Hydroxyethyl)piperazine-N'-(4-butanesulfonic acid) (HEPBS), or 1,4-piperazinediethanesulfonic acid (PIPES). Embodiment 10. The formulation of embodiment 9, wherein the buffer is HEPES, MES or MOPS. Embodiment 11. The formulation of any one of embodiments 1-10, wherein the buffer has a concentration of between about 15 mM and about 50 mM. Embodiment 12. The formulation of any one of embodiments 1-11, further comprising an excipient selected from the group consisting of arginine-glutamic acid, arginine, aspartic acid, sulfobutylether-beta-cyclodextrin (SBECD), polyethylene glycol, sodium sulfate, sodium hydrosulfite, trimethyl glycine, Triton X-100, Pluronic F-68, Pluronic F-127, polysorbate 80 (PS80), polysorbate 20 (PS20), poly(lactic-co-glycolic acid (PLGA), beta- cyclodextrin, gamma-cyclodextrin, sucrose, and trehalose. Embodiment 13. The formulation of any one of embodiments 1-12, wherein the camptothecin conjugate or a pharmaceutically acceptable salt thereof has a concentration of between about 0.5 mg/mL and about 80 mg/mL. Embodiment 14. The formulation of any one of embodiments 1-13, wherein the formulation is a pharmaceutically acceptable formulation. Embodiment 15. A method of preparing a lyophilized formulation, comprising lyophilizing the formulation of any one of embodiments 1-14. Embodiment 16. A lyophilized formulation prepared according to the method of embodiment 15. Embodiment 17. A method of treating cancer or an autoimmune disease, comprising administering to an individual in need thereof a reconstituted form of the lyophilized formulation of embodiment 16. Embodiment 18. The method of embodiment 17, further comprising administering to the individual an additional therapeutic agent. Embodiment 19. The method of embodiment 18, wherein the additional therapeutic agent is a therapeutic agent for treating cancer. Embodiment 20. The method of embodiment 18, wherein the additional therapeutic agent is a therapeutic agent for treating the autoimmune disease. Embodiment 21. A method of preparing the formulation of any one of embodiments 1- 14, comprising combining the camptothecin conjugate of Formula (IC) with the buffer. Embodiment 22. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.0 and about 4.8, wherein the solution comprises a buffer comprising an acetate salt. Embodiment 23. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.0 and about 4.8, wherein the solution comprises a buffer comprising glutamic acid. Embodiment 24. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.8 and about 5.6, wherein the solution comprises a buffer comprising histidine. Embodiment 25. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 6.0 and about 7.0, wherein the solution comprises a buffer comprising a sulfonic acid. Embodiment 26. The formulation or method of any one of embodiments 1-25, wherein y is 1. Embodiment 27. The formulation or method of any one of embodiments 1-26, wherein z is 8. Embodiment 28. The formulation or method of any one of embodiments 1-27, wherein p is 8. Embodiment 29. The formulation or method of any one of embodiments 1-28, wherein L is an anti-CD30 antibody. Embodiment 30. The formulation or method of embodiment 29, wherein L comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively. Embodiment 31. The formulation or method of embodiment 29 or 30, wherein the anti- CD30 antibody comprises a heavy chain variable region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO:8. Embodiment 32. The formulation or method of embodiment 29 or 30, wherein the anti- CD30 antibody comprises a heavy chain variable region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:8. Embodiment 33. The formulation or method of embodiment 29, wherein the anti-CD30 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8. Embodiment 34. The formulation or method of embodiment 29, wherein the anti-CD30 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:9 and a light chain comprising the amino acid sequence of SEQ ID NO:11. Embodiment 35. The formulation or method of embodiment 29, wherein the anti-CD30 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:10 and a light chain comprising the amino acid sequence of SEQ ID NO:11. Embodiment 36. The formulation or method of embodiment 29, wherein the anti-CD30 antibody is cAC10. Examples [0137] The following examples are offered to illustrate, but not to limit the claimed invention. Synthetic Examples [0138] The following abbreviations are used for the synthetic examples.

[0139] As used herein, terms such as “PEG2”, “PEG4”, “PEG8”, and “PEG12” refers to specific embodiments of -(CH2CH2-O)z- (the number corresponds to the subscription “z”). For example, “PEG2” refers to -(CH₂CH₂-O)₂-, “PEG4” refers to embodiments of -(CH₂CH₂- O)4-, “PEG8” refers to -(CH2CH2-O)8-, and “PEG12” refers to -(CH2CH2-O)8-. Example S1. Preparation of 7-methylamino deritivative-methylenedioxy camptothecin

[0140] Synthesis of Compound 4-a: 6-Amino-3,4-(methylenedioxy)acetophenone (5.00 g, 27.9 mmol) was dissolved in DCM (100 mL). The reaction was cooled to 0 ÛC and DIPEA (7.29 mL, 41.9 mmol) was added followed by slow addition of acetyl chloride (2.49 mL, 34.9 mL). The reaction was allowed to warm to room temperature and stirred for 30 minutes. Complete conversion was observed by UPLC-MS. The reaction was quenched with MeOH (5 mL), and the reaction was concentrated in vacuo to afford compound 4-a as a white solid used in the next step without further purification. Rt = 1.37 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C₁₁H₁₂NO₄222.08, found 222.11. [0141] Synthesis of Compound 4-b: Compound 4-a (27.9 mmol) from previous step was dissolved in AcOH (100 mL). HBr 33% w/w in AcOH (9.78 mL, 55.8 mmoL) was added slowly. Bromine (1.44 mL, 27.9 mmol) was added dropwise over 15 minutes. The reaction was stirred for 30 minutes at which time conversion to desired product was observed. The reaction was poured over ice water and the precipitate was collected by filtration and washed with water. The filtrate was dried to afford a yellow powder which was a mixture of the desired product compound 4-b with starting material and dibrominated product impurities which was used in the next step without further purification (7.2 g, 24 mmol, 86%). Rt = 1.58 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C11H11BrNO4299.99, found 299.90. [0142] Synthesis of Compound 4-c: Compound 4-b (7.2 g, 24 mmol) was dissolved in EtOH (100 mL). Concentrated HBr (5 mL) was added and the reaction was heated to reflux for 60 minutes. Nearly complete conversion to the deprotected product was observed. The reaction was concentrated in vacuo, diluted with DCM (200 mL) and H₂O (200) mL. The aqueous phase was extracted with DCM (3 x 200 mL), the collected organic phases were dried with MgSO4, filtered and concentrated in vacuo. The crude product was purified by column chromatography 0-10% MeOH in DCM. Fractions containing the desired product with minor impurity were concentrated to afford compound 4-c as a yellow powder (4.05 g, 15.7 mmol, 65%). Rt = 1.57 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C9H9BrNO3257.98, found 257.71. [0143] Synthesis of Compound 4-d: Compound 4-c (1.00 g, 3.87 mmol), p-TSA (667 mg, 3.87 mmol), and 4-Ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)- trione (1.02 g, 3.87 mmol, obtained from Avra Laboratories Pvt. Ltd.) were charged in a flask. DCM (5 mL) was added to homogenize the solids, and then evaporated under nitrogen. The neat solids were then heated to 120 ÛC under high vacuum (1 mbar) for 60 minutes. Reaction was cooled to room temperature, the crude product precipitated with H₂O^, filtered and washed with H₂O The precipitate was purified by column chromatography 0-10% MeOH in DCM. Fractions containing the desired product were concentrated in vacuo to afford compound 4-d as a brown solid (989 mg, 2.04 mmol, 53%). Rt = 1.57 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C₉H₉BrNO₃257.98, found 257.71. Rt = 1.62 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C22H17BrN2O6485.03, found 484.95. [0144] Synthesis of Compound 4: Compound 4-d (188 mg, 0.387 mmol) was dissolved in EtOH (5 mL). Hexamethylenetetramine (163 mg, 1.16 mmol) was added and the reaction as stirred at reflux for 90 minutes. The reaction was cooled and aq. conc. HCl (0.1 mL) was added. The reaction was concentrated and purified by prep-HPLC. Fractions containing the desired product were lyophilized to afford Compound 4 as an off white solid (109 mg, 0.259 mmol, 67%). Example S2. Preparation of MP-PEG4-Val-Lys-Gly-7-MAD-MDCPT (Ex_4-1)

[0145] Solid phase peptide synthesis of MP-PEG4-VK(Boc)G-OH: Unprotected glycine pre-loaded 1.1 mmol/g on 2-chlorotryityl resin was purchased from BAChem. Resin (1 gram) was added to reaction vessel. Resin washed with DMF 4 times and drained completely. Resin swelled by shaking in DMF for 30 minutes, and drained. Using the general coupling procedure Fmoc-Lys(Boc)-OH was coupled to the resin. The Fmoc was deprotected using the general deprotection procedure. Using the general coupling procedure Fmoc-Val-OH was coupled to the resin, followed by the general deprotection procedure. MP-PEG4-OH was coupled using the general coupling procedure. The resin was then washed with DCM 3 times, followed by MeOH 3 times, and placed under high vacuum overnight. The peptide was cleaved from the resin by stirring the resin in a solution of 1 mL Acetic Acid, 2 mL hexaflouroisopropanol, and 7 mL DCM for 1 hour. Resin was then filtered and rinsed with DCM 3 times, and then the solution was concentrated in vacuo. The white powder was dissolved in 2:1 DMA:H2O (3 mL) and purified by preparative HPLC using a 30 x 250 mm Phenomenex Max-RP 4 μm Synergi 80Å reverse phase column using a 5-60-95% gradient elution of MeCN (0.05% TFA) in aqueous 0.05% TFA described below. Fractions containing the desired product were lyophilized to afford a white powder (354 mg, 0.442 mmol, 40%). Rt = 1.39 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C36H59N6O14801.42, found 801.02. 5-60-95% Gradient Elution

[0146] General Fmoc deprotection procedure: A solution of 20% piperidine in DMF (10 mL) was added to the resin, shaken for 1 minute, and drained. Another 10 mL of 20% piperidine in DMF was added to the resin, shaken for 30 minutes, and drained. The resin washed with DMF 4 times and drained completely. [0147] General Coupling Procedure: A solution was prepared in DMF (10 mL) of Fmoc Amino Acid (3 mmol), HATU (3 mmol), DIPEA (6 mmol). The solution was added to the resin, and shaken for 60 minutes. The reaction vessel was drained and washed with DMF 4 times. [0148] Synthesis of MP-PEG4-VK(Boc)G-OSu: MP-PEG4-VKG-OH (90.0 mg, 0.112 mmol) was dissolved in anhydrous DMF (0.3 mL) and DIPEA (0.05 mL, 0.302 mmol) was added. TSTU (67.6 mg, 0.224 mmol) was added to the reaction vessel, and conversion to the N-hydroxysuccinimide (OSu) activated ester was monitored by UPLC-MS. Complete conversion was observed after 5 minutes. The reaction was acidified with AcOH (0.05 mL, 0.874 mmol). The reaction was purified by Biotage flash chromatography using 10G Ultra silica gel column with a gradient elution of 0-10% MeOH in DCM. Fractions containing the desired product were concentrated in vacuo to afford a white solid which was the desired product MP-PEG4-VK(Boc)G-OSu (91.2 mg, 0.102 mmol, 90%). Rt =1.48 General Method UPLC. MS (m/z) [M + H]⁺ calc. for C40H62N7O16898.44, found 898.33. [0149] Coupling MP-PEG4-VK(Boc)G-OSu with 7-MAD-MDCPT: A solution of 7- MAD-MDCPT (24 mg, 0.057 mmol) dissolved in anhydrous DMF (0.48 mL) was added directly to the reaction vessel with the MP-PEG4-VK(Boc)G-OSu (50 mg, 0.056 mmol). DIPEA (0.05 mL, .303 mmol) was added to the reaction vessel. The clear yellow solution turned opaque upon the addition of base. The reaction was monitored for completion by UPLC-MS. Complete conversion to the desired coupled product was observed after 5 minutes. The reaction was acidified with AcOH (0.05 mL, 0.87 mmol) and purified by filtration through silica gel column with a gradient elution of 0-10% MeOH in DCM. The eluent was concentrated in vacuo to afford a yellow solid which was the desired product MP- PEG4-VKG-7-MAD-MDCPT (32 mg, 0.027 mmol, 48%). Rt = 1.59 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C₅₈H₇₇N₉O₁₉1204.54, found 1204.25. [0150] Boc deprotection of MP-PEG4-VK(Boc)G-7-MAD-MDCPT: MP-PEG4- VK(Boc)-G-7-MAD-MDCPT was dissolved in 20% TFA in DCM. Reaction was monitored for completion by UPLC-MS. Complete conversion was observed after 10 minutes. The reaction was concentrated in vacuo, reconstituted in 10% AcOH in 2:1 DMA:H₂O, and purified by preparative HPLC using a 21 x250 mm Phenomenex Max-RP 4 μm Synergi 80Å reverse phase column using a 5-60-95% gradient elution of MeCN (0.05% TFA) in aqueous 0.05% TFA described previously. Fractions with absorbance at 385 nm were collected. The fractions containing the desired product were lyophilized to afford Ex_4-1 as yellow powder (33 mg, .030 mmol, 80%). Rt = 1.12 min General Method UPLC. MS (m/z) [M + H]⁺ calc. for C53H69N9O171104.49, found 1104.70. Example S3. Preparation of MP-PEG2-Val-Lys-Gly-7-MAD-MDCPT (Ex_4-2)

[0151] Ex_4-2 was synthesized using the general procedure described in Example S2, by replacing PEG4 with PEG2. Example S4. Preparation of MP-PEG8-Val-Lys-Gly-7-MAD-MDCPT (Ex_4-3)

[0152] Ex_4-3 was synthesized using the general procedure described in Example S2, by replacing PEG4 with PEG8. Example S5. Preparation of MP-PEG12-Val-Lys-Gly-7-MAD-MDCPT

[0153] Ex_4-4 was synthesized using the general procedure described in Example S2, by replacing PEG4 with PEG12. [0154] The following table summarizes the characterization data for Ex_4-2, Ex_4-3, and Ex_4-4.

[0155] Fully or partially reduced ADCs were prepared in 50% propylene glycol (PG) 1X PBS mixture. A half portion of the PG was added to reduced mAb, and half PG was added to the 1 mM DMSO camptothecin drug-linker stock. The PG/drug-linker mix was added to reduced mAb in 25% portions. After the addition of drug-linker was complete, excess drug- linker was removed by treating with activated charcoal (1 mg of charcoal to 1 mg of mAb). The charcoal was then removed via filtration, and the resulting ADC was buffer exchanged using a NAP5 or PD10 column, into 5% trehalose in 1X PBS pH 7.4. Biological Examples Example B1. In vitro small molecule and ADC evaluation [0156] In vitro potency was assessed on multiple cancer cell lines. All cell lines were authenticated by STR profiling at IDEXX Bioresearch and cultured for no more than 2 months after resuscitation. Cells cultured in log-phase growth were seeded for 24 hours in 96- well plates containing 150 ^l RPMI 1640 supplemented with 20% FBS. Serial dilutions of antibody-drug conjugates in cell culture media were prepared at 4x working concentrations, and 50 ^l of each dilution was added to the 96-well plates. Following addition of test articles, cells were incubated with test articles for 4 days at 37 °C. After 96 hours, growth inhibition was assessed by CellTiter-Glo® (Promega, Madison, WI) and luminescence was measured on a plate reader. The IC₅₀ value, determined in triplicate, is defined here as the concentration that results in 50% reduction in cell growth relative to untreated controls. [0157] In the following Tables IC50 values for ADCs are given in ng/mL and mmol/mL concentrations, respectively, with values in the parenthesis representing percent cells remaining at highest concentration tested (1000 ng/mL for ADCs, unless otherwise indicated) relative to untreated cells. Cell viability was determined by CellTiter-Glo staining after 96h exposure to ADC. ND = Not Determined. Ag1 is an antibody targeting a ubiquitous and readily internalizable antigen on cancer cells, Ag2 is cAC10 antibody targeting CD30(+) cancer cells, Ag3 is h1F6 antibody targeting CD70(+) cancer cells, Ag4 is hMEM102 antibody targeting CD48(+) cancer cells, Ag5 is h20F3 antibody targeting NTB-A expressing cancer cells, and h00 is a non-binding control antibody. [0158] Tables 1A-1D. In vitro potency (IC50 values) of camptothecin ADCs (DAR = 8). A. anti-Ag1 ADCs targeting renal carcinoma cells (786-O), pancreatic cancer cells (BxPC3), hepatic carcinoma cells (HepG2), acute promyelocytic leukemia cells (HL-60), Hodgkin’s lymphoma cells (L540cy), multiple myeloma cells (MM.1R), acute myeloid leukemia cells (MOLM13), Burkitt’s lymphoma cells (Ramos), melanoma cells (SK-MEL-5) and B- lymphocyte cancer cells (SU-DHL-4 and U266), B. anti-Ag2 ADCs targeting Hodgkin’s lymphoma cells (DEL and L540cy) and non-Hodgkin’s lymphoma cells (Karpas 299), which are antigen positive, with testing aginst renal carcinoma cells (786-O), which are antigen negative, C. anti-Ag3 ADCs targeting renal carcinoma cells (786-O, Caki-1 and UM-RC-3), and Burkitt’s lymphoma cells (Raji), and D. anti-Ag4 ADCs and anti-Ag5 ADCs targeting multiple myleoma cells (EJM, KMM-1, MM.1R), and B lymphocyte cancer cells (NCI-H929 and U-266), which are antigen positive, with testing against an antigen negative lymphoblast cell line (TF-1a). Ex_8-1a refers to Ag1-MC-GGFG-NHCH2-DXd(1) and Ex_4-1 refers to MP-PEG4-VKG-7-MAD-MDCPT. Table 1A. Anti-Ag1 ADC

Table 1B. Anti-Ag2 ADCs

Table 1C. Anti-Ag3 ADCs

Table 1D. Anti-Ag4 ADC and anti-Ag5 ADC

Example B2. Differential Activity on CD30+ parental DEL and CD30 /MDR+ DEL-BVR cell lines [0159] Table 2. Differential activity of camptothecin Ag2-Ex_4-1(DAR = 8) on CD30+ parental DEL and CD30 /MDR+ DEL-BVR cell lines. The parental DEL lymphoma cell line was cultured in the presence of brentuximab vedotin to induce over-expression of the MDR phenotype, resulting in the DEL brentuximab vedotin resistant line (DEL-BVR). Brentuximab vedotin, which is Ag2-vc-MMAE (DAR = 4) was included as a control. Ex_4- 1 referes to MP-PEG4-VKG-7-MAD-MDCPT . Table 2

[0160] Tables 2A and 2B show the results of the evaluation of select peptide-based camptothecin anti-Ag1 (DAR = 8) ADCs varying in hydrophobicity against various cancer cell lines. [0161] Table 2A: renal cancer cells (786-O), pancreatic cancer cells (BxPC3), hepatic cancer cells (HepG2), MDR(-) and MDR(+) acute promyelocytic leukemia cells (HL-60 and HL60/RV, respectively), and Hodgkin’s lymphoma cells (L540cy). [0162] Table 2B: multiple myeloma cells (MM.R1), acute myeloid leukemia cells (MOLM13), Burkitt’s lymphoma cells (Ramos), melanoma cells (SK-MEL-5) and B- lymphocyte cancer cells (SU-DHL-4 and U266). Table 2A

Table 2B

Tests on Formulations Example 1. Effect of buffer and pH on the stability of Compound 1 formulation [0163] The following formulations containing 10 mg/mL of Compound 1 were prepared and checked for LLPS. Compound 1 has the structure shown below. Formulations that initially showed no LLPS at the initial time point (T0) were checked 1 hour after T0 and 18 hours after T0. The results are provided below in Table 3.

Table 3

Example 2. Effect of buffer, pH, and excipient on the stability of Compound 1 formulation [0164] The formulations provided in Table 4 were prepared and analyzed by different analytical methods to determine the effect of buffer, pH, and excipient on the stability of Compound 1 formulation. Formulations with Trehalose contain trehalose dihydrate at 7% (w/v). Table 4

[0165] For Formulation Nos.1-9 provided in Table 4, particle formation was tested at the initial time point (T0) and 7 days after storage at 5 ºC. The results are shown in Table 5. Table 5

CC: Clear Colorless TMTC: Too many to counts EFP: Essentially Free of Particles [0166] For Formulation Nos.1-9 provided in Table 4, size exclusion chromatography (SEC) was conducted at the initial time point (T0) and 7 days after storage at 5 ºC to determine the extent of aggregation and degradation. The results are provided in Table 6 and shown in FIGs.1 and 2. %Main means the percentage of the area of the main peak (corresponding to Compound 1), %HMW means the percentage of the areas of high molecular weight (HMW) species, and %LMW means the percentage of the areas of low molecular weight (LMW) species. Table 6

[0167] For Formulation Nos.2-8 provided in Table 4, imaged capillary isoelectric focusing (icIEF) was conducted at the initial time point (T0) and 7 days after storage at 5 ºC to determine the charge profile of Compound 1. The results are provided in Table 7 and shown in FIGs.3 and 4. %Main means the percentage of the area of the main peak (corresponding to Compound 1), %Acidic means the percentage of the areas of the acidic species, and %Basic means the percentage of the areas of the basic species. Table 7

[0168] For Formulation Nos.1-12 provided in Table 4, particle formation was tested at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC. The results are provided in Table 8. Table 8

CC: Clear Colorless TMTC: Too many to counts EFP: Essentially Free of Particles X/Y vials: X particles in Y vials [0169] For Formulation Nos.1-12 provided in Table 4, SEC was conducted at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC to determine the extent of aggregation and degradation. The results are provided in Table 9 and shown in FIGs.5 and 6. Table 9

[0170] For Formulation Nos.1-8 provided in Table 4, icIEF was conducted at the initial time point (T0), 3 days, and 7 days after storage at 40 ºC to determine the charge profile of Compound 1. The results are provided in Table 10 and shown in FIGs.7 and 8. Table 10

[0171] For Formulation Nos.1-9 provided in Table 4, particle formation was tested at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC). The results are provided in Table 11. Table 11

CC: Clear Colorless TMTC: Too many to counts EFP: Essentially Free of Particles [0172] For Formulation Nos.1-9 provided in Table 4, SEC was conducted at the initial time point (T0), 3 cycles, and 5 cycles after freeze/thaw (-80 ºC) to determine the extent of aggregation and degradation. The results are provided in Table 12 and shown in FIGs.9 and 10. Table 12

[0173] For Formulation Nos.1-8 provided in Table 4, icIEF was conducted at the initial time point (T0), 3 cycles, and 5 cycles after storage at freeze/thaw (-80 ºC) to determine the charge profile of Compound 1. The results are provided in Table 13 and shown in FIGs.11 and 12. Table 13

Example 3. Effect of pH and excipient on the stability of Compound 1 formulation in certain buffers [0174] Based on the results of Example 2, the formulations provided in Table 14 were prepared and analyzed by different analytical methods to determine the effect of pH and excipient on the stability of Compound 1 formulation in certain buffers. Table 14

[0175] For the formulations provided in Table 14, particle formation was tested at the initial time point (T0), 3 days after storage at 40 ºC, and 5 days after storage at 40 ºC. The results are shown in Table 15. Table 15

CC: Clear Colorless TMTC: Too many to counts EFP: Essentially Free of Particles [0176] For the formulations provided in Table 14, SEC was conducted at the initial time point (T0), 3 days after storage at 40 ºC, and 5 days after storage at 40 ºC to determine the extent of aggregation and degradation. The results are provided in Table 16 and shown in FIGs.13-16. Table 16

Example 4. Preparation of lyophilized formulations of Compound 1 [0177] The formulations provided in Table 17 were prepared. Table 17

fill). Lyophilized formulations were prepared by lyophilizing the formulations using the procedures provided below and analyzed by different analytical methods.

[0179] The lyophilized formulations were examined at the initial time point (T0), 7 days after storage at 50 ºC, and 14 days after storage at 50 ºC. The results are shown in Table 18. Table 18

[0180] The lyophilized formulations were analyzed by SEC at the initial time point (T0), 7 days after storage at 50 ºC, 14 days after storage at 50 ºC, and 28 days after storage at 50 ºC. The results are provided in Table 19 and shown in FIGs.17 and 18. Table 19

[0181] The formulations in Table 20 were prepared and lyophilized using procedures similar to those discussed above. The lyophilized formuations were analyzed for water content by Karl Fischer titration. The calculated %moisture determined at T0 was 1.6% for lyophilized Formulation No.1 and 0.2% for lyophilized Formulation No.2. In comparison, the calculated %moisture determined at T0 was 0.5% for lyophilized Formulation No.1 with 12 mg/mL Compound 1 and 0.2% for lyophilized Formulation No.2 with 12 mg/mL Compound 1. The lyophilized formulations were also analyzed by SEC at the initial time point (T0), 7 days after storage at 50 ºC, 14 days after storage at 50 ºC, and 28 days after storage at 50 ºC. The results showed trends comparable to the results for the corresponding formulations with lower Compound 1 concentration in Table 19. Table 20

Example 5. Photostability Study [0182] The formulations in Table 21 were prepared. Table 21

[0183] Glass vials were filled with the formulations (2 mL) and stored under ambient light stress or in dark condition for 7 days. The samples were analyzed by SEC at the initial time point (T0), day 1, day 2, day 3, and day 7. And the results are provided in Table 22 (%HMW) and Table 23 (%LMW). Table 22. Changes in %HMW

Table 23. Changes in %LMW

[0184] The low concentration formulations showed similar trends as the corresponding high concentration formulations. After 7-day storage under ambient light stress, the %HMW for Formulation No.1 is 4.31 and the %LMW for Formulation No.1 is 4.9. After 7-day storage under ambient light stress, the %HMW for Formulation No.3 is 5.6 and the %LMW for Formulation No.1 is 5.2. Example 6. Freeze/Thaw Stability Study [0185] The formulations in Table 24 were prepared. Table 24

[0186] SEC was conducted at the initial time point (T0) and 5 cycles after freeze/thaw (- 80 ºC) to determine the extent of aggregation and degradation. The results are provided in Table 25. Table 25

Table of Sequences

Claims

CLAIMS 1. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising an acetate salt, wherein the formulation has a pH of between about 4.0 and about 4.8. 2. The formulation of claim 1, wherein the buffer is sodium acetate. 3. The formulation of claim 1 or 2, wherein the pH is about 4.5. 4. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising glutamic acid, wherein the formulation has a pH of between about 4.0 and about 4.8. 5. The formulation of claim 4, wherein the pH is about 4.5. 6. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8; and a buffer comprising histidine, wherein the formulation has a pH of between about 4.8 and about 5.6. 7. The formulation of claim 6, wherein the pH is about 5.5. 8. A formulation comprising: a camptothecin conjugate of Formula (IC):

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1,

2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2,

3,

4,

5,

6,

7,

8, 9, or 10, or is 2, 4 or 8; and a buffer comprising a sulfonic acid, wherein the formulation has a pH of between about 6.0 and about 7.0.

9. The formulation of claim 8, wherein the buffer is 2-(N-morpholino)ethanesulfonic acid (MES), benzenesulfonic acid, 3-(N-morpholino)propanesulfonic acid (MOPS), methanesulfonic acid, N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), 4-(2- hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), polystyrene sulfonic acid, N-(2- Hydroxyethyl)piperazine-N'-(4-butanesulfonic acid) (HEPBS), or 1,4- piperazinediethanesulfonic acid (PIPES).

10. The formulation of claim 9, wherein the buffer is HEPES, MES or MOPS.

11. The formulation of any one of claims 1-10, wherein the buffer has a concentration of between about 15 mM and about 50 mM.

12. The formulation of any one of claims 1-11, further comprising an excipient selected from the group consisting of arginine-glutamic acid, arginine, aspartic acid, sulfobutylether-beta-cyclodextrin (SBECD), polyethylene glycol, sodium sulfate, sodium hydrosulfite, trimethyl glycine, Triton X-100, Pluronic F-68, Pluronic F-127, polysorbate 80 (PS80), polysorbate 20 (PS20), poly(lactic-co-glycolic acid (PLGA), beta-cyclodextrin, gamma-cyclodextrin, sucrose, and trehalose.

13. The formulation of any one of claims 1-12, wherein the camptothecin conjugate or a pharmaceutically acceptable salt thereof has a concentration of between about 0.5 mg/mL and about 80 mg/mL.

14. The formulation of any one of claims 1-13, wherein the formulation is a pharmaceutically acceptable formulation.

15. A method of preparing a lyophilized formulation, comprising lyophilizing the formulation of any one of claims 1-14.

16. A lyophilized formulation prepared according to the method of claim 15.

17. A method of treating cancer or an autoimmune disease, comprising administering to an individual in need thereof a reconstituted form of the lyophilized formulation of claim 16.

18. The method of claim 17, further comprising administering to the individual an additional therapeutic agent.

19. The method of claim 18, wherein the additional therapeutic agent is a therapeutic agent for treating cancer.

20. The method of claim 18, wherein the additional therapeutic agent is a therapeutic agent for treating an autoimmune disease.

21. A method of preparing the formulation of any one of claims 1-14, comprising combining the camptothecin conjugate of Formula (IC) with the buffer.

22. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.0 and about 4.8, wherein the solution comprises a buffer comprising an acetate salt.

23. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.0 and about 4.8, wherein the solution comprises a buffer comprising glutamic acid.

24. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 4.8 and about 5.6, wherein the solution comprises a buffer comprising histidine.

25. A method of reducing liquid-liquid phase separation of an aqueous formulation of a camptothecin conjugate of Formula (IC),

or a pharmaceutically acceptable salt thereof, wherein: L is an antibody, y is 1, 2, 3, or 4, or is 1 or 4, z is an integer from 2 to 12, or is 2, 4, 8, or 12, and p is 1-16, or is 2, 3, 4, 5, 6, 7, 8, 9, or 10, or is 2, 4 or 8, the method comprising formulating the camptothecin conjugate or a pharmaceutically acceptable salt thereof in a solution having a pH of between about 6.0 and about 7.0, wherein the solution comprises a buffer comprising a sulfonic acid.

26. The formulation or method of any one of claims 1-25, wherein y is 1.

27. The formulation or method of any one of claims 1-26, wherein z is 8.

28. The formulation or method of any one of claims 1-27, wherein p is 8.

29. The formulation or method of any one of claims 1-28, wherein L is an anti-CD30 antibody.

30. The formulation or method of claim 29, wherein L comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 comprising the amino acid sequences of SEQ ID NOs: 1, 2, 3, 4, 5, and 6, respectively.

31. The formulation or method of claim 29 or 30, wherein the anti-CD30 antibody comprises a heavy chain variable region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO:8.

32. The formulation or method of claim 29 or 30, wherein the anti-CD30 antibody comprises a heavy chain variable region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:8.

33. The formulation or method of claim 29, wherein the anti-CD30 antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8.

34. The formulation or method of claim 29, wherein the anti-CD30 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:9 and a light chain comprising the amino acid sequence of SEQ ID NO:11.

35. The formulation or method of claim 29, wherein the anti-CD30 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:10 and a light chain comprising the amino acid sequence of SEQ ID NO:11.

36. The formulation or method of claim 29, wherein the anti-CD30 antibody is cAC10.