Camptothecin conjugates

Abstract

To provide antibody conjugates including camptothecin compounds, with methods of use and preparation.SOLUTION: The invention provides, inter alia, camptothecin conjugates, camptothecin-linker compounds and camptothecin compounds, and methods of preparing and using them, and intermediates thereof. The camptothecin conjugates of the present invention are stable in blood circulation, yet capable of inflicting cell death once a free drug is released from a conjugate in the vicinity or within tumor cells.SELECTED DRAWING: None

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 681,847, filed Jun. 7, 2018, and U.S. Provisional Patent Application No. 62 / 777,491, filed Dec. 10, 2018, both of which are hereby incorporated by reference in their entirety for all purposes.

Background Art

[0002] Antibodies (mAbs) for targeted delivery of cytotoxic agents to tumor cells have been investigated. Various drug classes have been evaluated for targeted delivery by antibodies, but only a few drug classes have been demonstrated to have a suitable toxicity profile and other pharmacological properties to justify clinical development while being sufficiently active as antibody - drug conjugates. One drug class of interest is camptothecin.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Generally, the design of antibody - drug conjugates (ADCs) by conjugation of cytotoxic agents to antibodies via linkers requires consideration of various factors, including the presence of a conjugate handle on the drug for attachment to the linker and linker technology for stably attaching the drug to the antibody under conditions. The conjugate handle for the parent compound in this class is the C20 hydroxyl functionality, in which case the linker is attached via a carbonate functionality (see, for example, Walker, M.A. et al. Bioorganic & Medicinal Chemistry Letters (2002) 12(2): 217 - 219). However, carbo The problem is that the native functional group is usually unstable to hydrolysis, which causes premature release of the free drug into the systemic circulation, leading to a decrease in ADC efficacy, insufficient immunological specificity of the conjugate, and an increase in toxicity. Therefore, to increase the amount of drug delivered to the desired site of action (sit), a camptothecin conjugate with improved stability is needed in the art. The present invention addresses such needs and other needs.

Means for Solving the Problems

[0004] The present invention provides, inter alia, camptothecin conjugates, camptothecin-linker compounds and camptothecin compounds, methods for preparing and using them, and intermediates thereof. The camptothecin conjugates of the present invention are stable in the blood circulation, but can cause cell death when the free drug is released from the conjugate near or inside the tumor cells.

[0005] In one exemplary embodiment, a camptothecin conjugate having the following formula: L-(Q-D) p or a salt thereof [wherein L is a ligand unit, the subscript p is an integer from 1 to 16, Q is the following: -Z-A-, -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, Z-A-S * -W-, -Z-A-S * -W-RL-, -Z-A-B(S * )-RL-, -Z-A-B(S * )-W-, -Z-A-B(S * )-W-RL- and -Z-A-B(S * )-RL-Y- A linker unit having a formula selected from the group consisting of wherein Z is a stretcher unit, A is a bond or a connector unit, B is a parallel connector unit, S * is a dispenser, RL is a cleavable linker, W is an amino acid unit, Y is a spacer unit, D is as follows:

Chemical formula

Chemical formula

[0006] The other principle embodiments described above are camptothecin-linker compounds useful as intermediates for preparing camptothecin conjugates, which camptothecin-linker compounds comprise camptothecin and a linker unit (Q), the linker unit comprising a stretcher unit precursor (Z') capable of forming a covalent bond to a targeting ligand that provides a ligand unit, and in some embodiments of Q having no amino acid units, a releasable linker (RL) that is a glucuronide unit.

[0007] In another aspect, provided herein is a method of treating cancer comprising administering to a subject in need thereof a camptothecin conjugate described herein.

[0008] In another aspect, provided herein is a kit comprising a camptothecin conjugate described herein.

Brief Description of the Drawings

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BEST MODE FOR CARRYING OUT THE INVENTION

[0024] Definitions Unless otherwise specified, the following terms and phrases used in this specification are intended to have the following meanings. When a trade name is used in this specification, this trade name includes, unless otherwise indicated by the context, product formulations, generic drugs, and the active pharmaceutical ingredients of the trade name product.

[0025] The term "antibody" as used herein is used in the broadest sense and specifically encompasses 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, consisting of two identical pairs of immunoglobulin chains, each pair having one light chain and one heavy chain. In each pair, the light chain and heavy chain variable regions (V L and V H ) together are primarily responsible for binding to the antigen. The light chain and heavy chain variable domains consist of framework regions interrupted by three hypervariable regions, also called "complementary determining regions" or "CDRs". The constant regions can 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 thereof. An 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.

[0026] As used herein, the term "monoclonal antibody" refers to an antibody obtained from a substantially homogeneous population of antibodies, i.e., the individual antibodies comprising the population are identical except for possible naturally occurring mutations that may be present in trace amounts. Monoclonal antibodies are highly specific and are directed against a single antigenic site. The modifier "monoclonal" indicates the property of an antibody obtained from a substantially homogeneous population of antibodies and should not be construed to require that the antibody be produced by any particular method.

[0027] An "intact antibody" is one that comprises an antigen-binding variable region, and, where appropriate for the antibody class, a light chain constant domain (C L ) and heavy chain constant domains, C H 1, C H 2, C H 3 and C H 4. The constant domains may be the native sequence constant domains (e.g., the native sequence constant domains in humans) or amino acid sequence variants thereof.

[0028] An "antibody fragment" comprises a portion of an intact antibody, including the antigen-binding region or variable region thereof. Examples of antibody fragments include Fab, Fab’, F(ab’)2 and Fv fragments, diabodies, triabodies, tetra-bodies, linear antibodies, single-chain antibody molecules, scFv, scFv-Fc, multispecific antibody fragments formed from antibody fragments, fragments generated by a Fab expression library, or any epitope-binding fragment of the foregoing that immunospecifically binds to a target antigen (e.g., a cancer cell antigen, a viral antigen or a microbial antigen).

[0029] An "antigen" is a substance to which an antibody specifically binds.

[0030] The terms "specific binding" and "specifically binds" mean that an antibody or antigen derivative binds with high selectivity to its corresponding epitope on a target antigen and does not bind to a number of other antigens. Typically, an antibody or antibody derivative binds with an affinity of at least about 1x10 -7 M, and preferably 10 -8 M to 10 -9M, 10 -10 M, 10 -11 M or 10 -12 It binds with the affinity of M and binds to a predetermined antigen with an affinity that is at least twice as high as its affinity when binding to a non-specific antigen other than the predetermined antigen or an antigen closely related thereto (e.g., B SA, casein), binds to the predetermined antigen.

[0031] The term "inhibit" or "inhibition of" means being reduced by a measurable amount or being completely prevented.

[0032] The term "therapeutically effective amount" refers to the amount of a conjugate effective in treating a disease or disorder in a mammal. In the case of cancer, a therapeutically effective amount of the conjugate reduces the number of cancer cells, shrinks the tumor size, inhibits the invasion of cancer cells into peripheral organs (i.e., delays to some extent and preferably stops), inhibits tumor metastasis (i.e., delays to some extent and preferably stops), inhibits tumor growth to some extent, and / or alleviates one or more of the symptoms associated with cancer to some extent. The drug may be cytostatic and / or cytotoxic to the extent that the drug can inhibit growth and / or kill existing cancer cells. In the case of cancer treatment methods, effectiveness can be measured, for example, by assessing the time to disease progression (TTP) and / or by determining the response rate (RR).

[0033] The term "substantial" or "substantially" means most, i.e., greater than 50% of a mixture or population of samples, preferably 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% of the population.

[0034] The term "cytotoxic activity" refers to the cell-killing effect of a drug or a camptothecin conjugate or an intracellular metabolite of a camptothecin conjugate. Cytotoxic activity is IC50 It can be expressed as a value, which is the concentration (mole or mass) per unit volume at which half of the cells are surviving.

[0035] The term "cytostatic activity" refers to the antiproliferative effect of a drug or a camptothecin conjugate or an intracellular metabolite of a camptothecin conjugate.

[0036] The term "cytotoxic agent", as used herein, refers to a substance that has cytotoxic activity and causes cell destruction. This term is intended to include chemotherapeutic agents, as well as toxins such as small molecule toxins or enzyme active toxins of bacterial, fungal, plant or animal origin, including synthetic analogs and their derivatives.

[0037] The term "cytostatic agent", as used herein, refers to a substance that inhibits the function of cells, including cell growth or proliferation. Cytostatic agents include protein inhibitors, such as inhibitors like enzyme inhibitors. Cytostatic agents have cytostatic activity.

[0038] The terms "cancer" and "cancerous" refer to, or describe being, a physiological state or disorder in a mammal that is typically characterized by unregulated cell growth. A "tumor" contains one or more cancerous cells.

[0039] "Autoimmune disease", as used herein, refers to a disease or disorder that arises from and targets the individual's own tissues or proteins.

[0040] "Patient", as used herein, refers to the subject to whom the camptothecin conjugate of the present invention is administered. Patients include, but are not limited to, humans, rats, mice, guinea pigs, non-human primates, pigs, goats, cows, horses, dogs, cats, birds and poultry . Usually, the patient is a rat, a mouse, a dog, a human or a non-human primate, and more generally, a human.

[0041] Unless otherwise indicated by context, the term "treating" or "treatment" refers to therapeutic and prophylactic measures, the purpose of which is to inhibit or slow down (reduce) undesirable physiological changes or disorders such as the onset or spread of cancer. With respect to the objects of the present invention, beneficial or desired clinical results, whether detectable or undetectable, include, but are not limited to, alleviation of symptoms, reduction of the degree of disease, stabilization of the disease (i.e., non-worsening), delay or deceleration of disease progression, improvement or alleviation of the disease state, and remission (whether partial or complete). "Treatment" may also mean prolonging survival compared to that expected in the absence of treatment. Those in need of treatment include those who already have the condition or disorder and those who are prone to having the condition or disorder.

[0042] In the context of cancer, the term "treating" means any one or all of killing tumor cells, inhibiting the growth of tumor cells, cancer cells or tumors, inhibiting the replication of tumor cells or cancer cells, reducing the overall tumor burden, or reducing the number of cancerous cells, and improving one or more symptoms associated with the disease.

[0043] In the context of autoimmune diseases, the term "treating" includes, but is not limited to, any one or all of inhibiting the replication of cells associated with the state of the autoimmune disease, including cells that produce autoantibodies, reducing the autoantibody load, and improving one or more symptoms of the autoimmune disease.

[0044] As used herein, the term "compound" refers to and includes, whether or not explicitly named or represented by structure, a chemical compound itself, and, unless the context clearly excludes its salt forms, such salt forms. The term "compound" further includes solvate forms of the compound in which a solvent is non-covalently bound to the compound or in which the carbonyl group of the compound is reversibly covalently bound to the compound as in the case of hydration to form a gem-diol. Solvate forms include the form of the compound itself, and its salt forms, including hemisolvates, monosolvates, disolvates, including hydrates, and when the compound can bind to two or more solvent molecules, the two or more solvent molecules may be the same or different.

[0045] In some instances, the compounds of the invention include explicit reference to one or more of the above forms, e.g., salts and solvates, which does not imply any particular solid state form of the compound. However, such reference is for emphasis only and should not be construed as excluding any of the other forms identified above. Further, where the salts and / or solvate forms of a compound or ligand-drug conjugate composition are not explicitly referred to, such omission should not be construed as excluding the salts and / or solvate forms of the compound or conjugate unless the context clearly indicates such exclusion.

[0046] As used herein, the phrase "its salts" refers to salt forms of a compound (e.g., a drug, drug linker compound or ligand-drug conjugate compound). The salt forms of a compound include one or more internal salt forms and / or inclusion of another molecule such as an acetate ion, succinate ion or other counterion. The counterion in the salt form of a compound is usually an organic or inorganic moiety that stabilizes the charge in the parent compound Yes. The salt form of a compound has one or more charged atoms in its structure. When multiple charged atoms are part of the salt form, multiple counterions and / or a multiply charged counterion are present. Thus, the salt form of a compound typically has one or more charged atoms corresponding to the atoms of the non-salt form of the compound and one or more counterions. In some embodiments, the non-salt form of the compound contains at least one amino group or other basic moiety, and thus, in the presence of an acid, an acid addition salt with the basic moiety is obtained. In other embodiments, the non-salt form of the compound contains at least one carboxylic acid group or other acidic moiety, and thus, in the presence of a base, a carboxylate anion or other anionic moiety is obtained. Exemplary salts include, but are not limited to, sulfate, trifluoroacetate, citrate, acetate, oxalate, chloride, bromide, iodide, nitrate, bisulfate, phosphate, acid phosphate, isonicotinate, lactate, salicylate, citrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate ate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, and pamoate (i.e., 1,1'-methylene-bis-(2-hydroxy-3-naphthoate)).

[0047] A pharmaceutically acceptable salt is a salt form of a compound suitable for administration to the subjects described herein, and in some embodiments, contains a countercation or counteranion described by P. H. Stahl and C. G. Wermuth, editors, Handbook of Pharmaceutical Salts: Properties, Selection and Use, Weinheim / Zurich: Wiley-VCH / VHCA, 2002.

[0048] The linker unit is a bifunctional moiety that attaches the camptothecin in the camptothecin conjugate to the ligand unit. The linker units of the present invention have several components (e.g., in some embodiments, a stretcher unit having a basic unit; a connector unit that may or may not be present; a parallel connector unit that may or may not be present as well; a releasable linker; and a spacer unit that may or may not be present as well).

[0049] "PEG", "PEG unit" or "polyethylene glycol" as used herein is an organic moiety that includes repeating ethyleneoxy subunits and can be polydisperse, monodisperse or individualized (i.e., having an individual number of ethyleneoxy subunits). Polydisperse PEG is a heterogeneous mixture of sizes and molecular weights, while monodisperse PEG is typically purified from a heterogeneous mixture and thus results in a single chain length and molecular weight. Preferred PEG units are individual PEGs which are compounds synthesized in a stepwise manner rather than by a polymerization process. Individual PEGs result in single molecules having a defined and specified chain length.

[0050] The PEG units provided herein include one or more polyethylene glycol chains, each containing one or more ethyleneoxy subunits covalently bonded to each other. The polyethylene glycol chains can be linked together, for example, in a linear, branched, or star-shaped configuration. Usually, at least one of the polyethylene glycol chains before incorporation into the camptothecin conjugate is derivatized at one end by an alkyl moiety substituted with an electrophilic group for covalent bonding to the carbamate nitrogen of the methylene carbamate unit (i.e., represents an example of R). Usually, the terminal ethyleneoxy subunits in each polyethylene glycol chain that are not involved in the covalent bonding to the remainder of the linker unit are modified by a PEG capping unit, usually an alkyl optionally substituted such as -CH3, -CH2CH3, or -CH2CH2CO2H. Preferred PEG units are single polyethylene glycol chains having 4 to 24 -CH2CH2 O-subunits covalently bonded in series and terminated at one end by a PEG capping unit.

[0051] Unless otherwise indicated, the term "alkyl", by itself or as part of another term, refers to a substituted or unsubstituted straight-chain or branched saturated or unsaturated hydrocarbon having the indicated number of carbon atoms (e.g., "-C1-C8 alkyl" or "-C1-C 10"Alkyl" refers to an alkyl group having 1 to 8 or 1 to 10 carbon atoms, respectively. When the number of carbon atoms is not indicated, this alkyl group has 1 to 8 carbon atoms. Representative linear "-C1-C8 alkyl" groups include, but are not limited to, -methyl, -ethyl, -n-propyl, -n-butyl, -n-pentyl, -n-hexyl, -n-heptyl, and -n-octyl. On the other hand, branched -C3-C8 alkyl includes, but is not limited to, -isopropyl, -sec-butyl, -isobutyl, -tert-butyl, -isopentyl, and -2-methylbutyl. Unsaturated -C2-C8 alkyl includes, but is not limited to, -vinyl, -allyl, -1-butenyl, -2-butenyl, -isobutenylenyl, -1-pentenyl, -2-pentenyl, -3-methyl-1-butenyl, -2-methyl-2-butenyl, -2,3-dimethyl-2-butenyl, -1-hexenyl, 2-hexenyl, -3-hexenyl, -ethynyl, -propynyl, -1-butynyl, -2-butynyl, -1-pentynyl, -2-pentynyl, and -3-methyl-1-butynyl. Sometimes, the alkyl group is unsubstituted. The alkyl group may be substituted by one or more groups. In other embodiments, the alkyl group is saturated.

[0052] Unless otherwise indicated, "alkylene" by itself or as part of another term consists of the specified number of carbon atoms, usually 1 to 10 carbon atoms, and has two monovalent radical centers derived by removing two hydrogen atoms from the same carbon atom or two different carbon atoms of the parent alkane, and refers to a substituted or unsubstituted saturated branched or linear or cyclic hydrocarbon radical. Typical alkylene radicals include, but are not limited to: methylene (-CH2-), 1,2-ethylene (-CH2CH2-), 1,3-propylene (-CH2CH2CH2-), 1,4-butylene (-CH2CH2CH2CH2-), and the like. In a preferred embodiment, alkylene is a branched or linear hydrocarbon (i.e., it is not a cyclic hydrocarbon).

[0053] Unless otherwise indicated, "aryl", whether by itself or as part of another term, consists of the specified number of carbon atoms, usually 6 to 20 carbon atoms, and means a substituted or unsubstituted monovalent carbocyclic aromatic hydrocarbon radical derived by removing one hydrogen atom from a single carbon atom of a parent aromatic ring system. Some aryl groups are represented by exemplary structures as "Ar". Typical aryl groups include, but are not limited to, radicals derived from benzene, substituted benzene, naphthalene, anthracene, biphenyl, etc. An exemplary aryl group is the phenyl group.

[0054] Unless otherwise indicated, "arylene", whether by itself or as part of another term, is an aryl group as defined above having two covalent bonds (i.e., it is divalent), and is shown in the following structures using phenyl as an exemplary group and can be in ortho, meta or para orientation: [Chemical formula]

[0055] Unless otherwise indicated, "C3 - C8 heterocycle", whether by itself or as part of another term, has 3 to 8 carbon atoms (also called ring members) and 1 to 4 heteroatom ring members independently selected from N, O, P or S, and refers to a monovalent substituted or unsubstituted aromatic, or non - aromatic monocyclic or bicyclic ring system derived by removing one hydrogen atom from a ring atom of a parent ring system. One or more of the N, C or S atoms in the heterocycle can be oxidized. The ring containing heteroatoms can be aromatic or non - aromatic. A heterocycle in which all ring atoms are involved in aromaticity is called heteroaryl, and otherwise is called heterocyclic carbon.

[0056] Unless otherwise specified, the heterocyclic ring is attached to its pendant group at any heteroatom or carbon atom that provides a stable structure. Thus, a heteroaryl can be attached via an aromatic carbon of its aromatic ring system, termed a C-linked heteroaryl, or via a non-double-bonded N atom (i.e., not =N-) in its aromatic ring system, termed an N-linked heteroaryl. Thus, a nitrogen-containing heterocyclic ring can be either C-linked or N-linked and includes pyrrole moieties such as pyrrol-1-yl (N-linked) and pyrrol-3-yl (C-linked), and imidazole moieties such as imidazol-1-yl and imidazol-3-yl (both N-linked) and imidazol-2-yl, imidazol-4-yl, and imidazol-5-yl moieties (all of which are C-linked).

[0057] Unless otherwise indicated, "C3-C8 heteroaryl" is an aromatic C3-C8 heterocyclic ring, where the subscript number represents the total number of carbons in the cyclic ring system that is the heterocyclic ring, or the total number of aromatic carbons in the aromatic ring system that is the heteroaryl, and does not imply anything about the size of the ring system or the presence or absence of ring fusion. Representative examples of C3-C8 heterocyclic rings include, but are not limited to, pyrrolidinyl, azetidinyl, piperidinyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl, benzofuranyl, benzothiophene, indolyl, benzopyrazolyl, pyrrolyl, thiophenyl (thiophene), furanyl, thiazolyl, imidazolyl, pyrazolyl, pyrimidinyl, pyridinyl, pyrazinyl, pyridazinyl, isothiazolyl, and isoxazolyl.

[0058] The size of a complex ring or heteroaryl ring system, when explicitly indicated, is represented by the total number of atoms in the ring. For example, the designation as a 5- or 6-membered heteroaryl indicates the total number of aromatic atoms in the heteroaryl's heteroaromatic ring system (i.e., 5 or 6), but does not imply the number of aromatic heteroatoms or aromatic carbons in the ring system. Fused heteroaryl is explicitly specified or implied by its own context and is usually represented by the number of aromatic atoms in each aromatic ring that condenses together to form a fused heteroaromatic ring system. For example, 5,6-membered heteroaryl is an aromatic 5-membered ring fused to an aromatic 6-membered ring where one or both of the rings have aromatic heteroatoms or one heteroatom is shared between the two rings.

[0059] A complex ring fused to an aryl or heteroaryl such that the complex ring is in a non-aromatic state and becomes part of a larger structure through a bond by the non-aromatic portion of the fused ring system is an example of a complex ring which is optionally substituted and is substituted by ring condensation with the aryl or heteroaryl. Similarly, an aryl or heteroaryl fused to a complex ring or carbocycle which is part of a larger structure through a bond by the aromatic portion of the fused ring system is an example of an aryl or complex ring which is optionally substituted and is substituted by ring condensation with the complex ring or carbocycle.

[0060] Unless otherwise indicated, "C3-C8 heterocycle" refers to the C3-C8 heterocyclic as defined above, either by itself or as part of another term, where one of the hydrogen atoms of the heterocycle is replaced by a bond (i.e., it is divalent). Unless otherwise indicated, "C3-C8 hetero arylene" refers to the C3-C8 heteroaryl group as defined above, either by itself or as part of another term, where one of the hydrogen atoms of the heteroaryl group is replaced by a bond (i.e., it is divalent).

[0061] Unless otherwise indicated, "C3-C8 carbocyclic ring", either by itself or as part of another term, is a 3-, 4-, 5-, 6-, 7- or 8-membered monovalent substituted or unsubstituted saturated or unsaturated non-aromatic monocyclic or bicyclic carbocyclic ring derived by removing one hydrogen atom from the ring atoms of the parent ring system. Representative -C3-C8 carbocyclic rings include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentadienyl, cyclohexyl, cyclohexenyl, 1,3-cyclohexadienyl, 1,4-cyclohexadienyl, cycloheptyl, 1,3-cycloheptadienyl, 1,3,5-cycloheptatrieneyl, cyclooctyl and cyclooctadienyl.

[0062] Unless otherwise indicated, "C3-C8 carbocycle" refers to a C3-C8 carbocyclic group as defined above, wherein another hydrogen atom of the carbocyclic group is replaced by a bond (i.e., is divalent).

[0063] Unless otherwise indicated, the term "heteroalkyl", either by itself or in combination with another term, unless otherwise specified, is completely saturated or contains 1 to 3 degrees of unsaturation, contains the specified number of carbon atoms, and 1 to 10, preferably 1 to 3, heteroatoms selected from the group consisting of O, N, Si and S, and is a stable straight-chain or branched hydrocarbon or a combination thereof, wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen heteroatoms may optionally be quaternized. The heteroatoms O, N and S may be placed at any internal position of the heteroalkyl group or at the position where the alkyl group is attached to the remainder of the molecule. The heteroatom Si may be placed at any position of the heteroalkyl group, including the position where the alkyl group is attached to the remainder of the molecule.

[0064] Examples include -CH2-CH2-O-CH3, -CH2-CH2-NH-CH3, -CH2-CH2-N(CH3)-CH3, -CH2-S-CH2-CH3, -CH2-CH2-S(O)-CH3, -NH-CH2-CH2-NH-C(O)-CH2-CH3, -CH2-CH2-S(O)2-CH3, -CH=CH-O-CH3, -Si(CH3)3, -CH2-CH=N-O-CH3, and -CH=CH-N(CH3)-CH3. For example, up to two heteroatoms such as -CH2-NH-OCH3 and -CH2-O-Si(CH3)3 may be consecutive. Usually, C1-C4 heteroalkyl or heteroalkylene has 1-4 carbon atoms and 1 or 2 heteroatoms, and C1-C3 heteroalkyl or heteroalkylene has 1-3 carbon atoms and 1 or 2 heteroatoms. In some embodiments, the heteroalkyl or heteroalkylene is saturated.

[0065] Unless otherwise indicated, the term "heteroalkylene" by itself or in combination with another term means a divalent group derived from heteroalkyl (discussed above) exemplified by -CH2-CH2-S-CH2-CH2- and -CH2-S-CH2-CH2-NH-CH2-. In the case of a heteroalkylene group, the heteroatom can also occupy one or both of the terminal chains. Further, in the case of alkylene and heteroalkylene linking groups, the orientation of the linking group is not implied.

[0066] Unless otherwise indicated, "aminoalkyl" by itself or in combination with another term means a heteroalkyl in which the alkyl portion as defined herein is substituted by an amino, alkylamino, dialkylamino, or cycloalkylamino group means heteroalkyl. Exemplary non-limiting aminoalkyls are -CH2NH2, -CH2CH2NH2, -CH2CH2NHCH3 and -CH2CH2N(CH3)2, and further include branched species such as -CH(CH3)NH2 and -C(CH3)CH2NH2 in the (R)- or (S)-configuration. Alternatively, aminoalkyl is an alkyl moiety, group or substituent as defined herein, where the sp 3 carbon other than radical carbon is replaced by an amino or alkylamino moiety, in which case its sp 3 nitrogen replaces the sp 3 carbon of the alkyl, provided that at least one sp 3 carbon remains in that state. When referring to an aminoalkyl moiety as a substituent on a larger structure or another moiety, this aminoalkyl is covalently bonded to this structure or moiety via the carbon radical of the alkyl portion of the aminoalkyl.

[0067] Unless otherwise indicated, "alkylamino" and "cycloalkylamino", alone or in combination with another term, mean an alkyl or cycloalkyl radical as described herein, in which case the radical carbon of the alkyl or cycloalkyl radical is replaced by a nitrogen radical, provided that at least one sp 3 carbon remains in that state. In such cases where the alkylamino is substituted at that nitrogen by another alkyl moiety, the resulting substituted radical is sometimes referred to as a dialkylamino moiety, group or substituent, in which case the alkyl moieties substituting the nitrogen are independently selected.

[0068] Exemplary and non-limiting amino, alkylamino, and dialkylamino substituents include those having the structure -N(R’)2, where in these examples R’ is independently selected from hydrogen or C1-6 alkyl, typically from hydrogen or methyl, while in cycloalkylamines contained in heterocycloalkyl, both R’ together with the nitrogen to which they are attached define a heterocyclic ring. When both R’ are hydrogen or alkyl, this moiety is sometimes described as a primary amino group and a tertiary amine group, respectively. When one R’ is hydrogen and the other is alkyl, this moiety is sometimes described as a secondary amino group. Primary and secondary alkylamino moieties are more reactive as nucleophiles towards carbonyl-containing electrophilic centers, while tertiary amines are more basic.

[0069] “Substituted alkyl” and “substituted aryl” mean alkyl and aryl, respectively, where one or more hydrogen atoms, typically one hydrogen atom, are each independently replaced by a substituent. Exemplary substituents include, but are not limited to, -X, -R’, -OH, -OR’, -SR’, -N(R’)2, -N(R’)3, =NR’, -CX3, -CN, -NO2, -NR’C(=O)R’, -C(=O)R’, -C(=O)N(R’)2, -S(=O)2R’, -S(=O)2NR’, -S(=O)R’, -OP(=O)(OR’)2, -P(=O)(OR’)2, -PO3 = 、PO3H2, -C(=O)R’, -C(=S)R’, -CO2R’, -CO2 - 、-C(=S)OR’, -C(=O)SR’, -C(=S)SR’, -C(=O)N(R’)2, -C(=S)N(R’)2, and -C(=NR)N(R’)2, where each X is independently selected from the group consisting of the halogens: -F, -Cl, -Br, and -I, and each R’ is independently selected from -H, -C1-C 20 alkyl, -C6-C 20 aryl, -C3-C 14 heterocycle, protecting group, and prodrug moiety.

[0070] Furthermore, usually, the substituent is selected from the group consisting of -X, -R’, -OH, -OR’, -SR’, -N(R’)2, -N(R’)3, =NR’, -NR’C(=O)R’, -C(=O)R’, -C(=O)N(R’)2, -S(=O)2R’, -S(=O)2NR’, -S(=O)R’, -C(=O)R’, -C(=S)R’, -C(=O)N(R’)2, -C(=S)N(R’)2, and -C(=NR)N(R’)2, where each X is independently selected from the group consisting of -F and -Cl, or -X, -R’, -OH, -OR ’, -N(R’)2, -N(R’)3, -NR’C(=O)R’, -C(=O)N(R’)2, -S(=O)2R’, -S(=O)2NR’, -S(=O)R’, -C(=O)R’, -C(=O)N(R’)2, -C(=NR)N(R’)2, a protecting group, and a prodrug moiety, where each X is -F, and each R’ is hydrogen, -C1-C 20 alkyl, -C6-C 20 aryl, -C3-C 14 heterocycle, a protecting group, and a prodrug moiety, independently selected from the group consisting thereof.

[0071] In some embodiments, the alkyl substituent is selected from the group consisting of -N(R ’ )2, -N(R ’ )3, and -C(=NR)N(R ’ )2, and R’ is selected from the group consisting of hydrogen and -C1-C 20 alkyl. In other embodiments, the alkyl is substituted by a series of ethyleneoxy moieties that define PEG units. Similarly, the above-mentioned alkylene, carbocycle, carbocyclo, arylene, heteroalkyl, heteroalkylene, heterocycle, heterocyclo, heteroaryl, and heteroarylene groups may also be substituted.

[0072] "Protecting group", as used herein, means a moiety that prevents or reduces the ability of an atom or functional group to which it is attached to participate in unwanted reactions. Typical protecting groups for atoms or functional groups are presented in Greene (1999), "Protective Groups In Organic Synthesis, 3 rd Ed.", Wiley Interscience. Protecting groups for hetero atoms such as oxygen, sulfur and nitrogen are, in some instances, used to minimize or avoid its unwanted reactions with electrophilic compounds. In other instances, protecting groups are used to reduce or eliminate the nucleophilicity and / or basicity of unprotected heteroatoms. Non-limiting examples of protected oxygen are given by -OR PR where R PR is a protecting group for hydroxyl, which is usually protected as an ester (e.g., acetate, propionate or benzoate). Other protecting groups for hydroxyl avoid interfering with the nucleophilicity of organometallic reagents or other highly basic reagents, and hydroxyl is usually protected as an ether including alkyl or heterocycloalkyl ethers (e.g., methyl or tetrahydropyranyl ether), alkoxymethyl ethers (e.g., methoxymethyl or ethoxymethyl ether), optionally substituted aryl ethers and silyl ethers (e.g., trimethylsilyl (TMS), triethylsilyl (TES), tert-butyldiphenylsilyl (TBDPS), tert-butyldimethylsilyl (TBS / TBDMS), triisopropylsilyl (TIPS) and [2-(trimethylsilyl)ethoxy]-methylsilyl (SEM)). Nitrogen protecting groups include those for primary or secondary amines such as -NHR PR or -N(R PR )2- where at least one of R PR is a nitrogen atom protecting group or both of R PR together contain a protecting group.

[0073] A protecting group is suitable if it can prevent or avoid unwanted side reactions or premature loss of the protecting group under the reaction conditions necessary to effect a desired chemical transformation anywhere in the molecule and, if desired, during the purification of the newly formed molecule, and can be removed under conditions that do not adversely affect the structure or stereochemical integrity of the newly formed molecule. By way of example, and not limitation, suitable protecting groups may include those already described for protecting functional groups. Suitable protecting groups are sometimes those used in peptide coupling reactions.

[0074] “Aromatic alcohol” refers to an aromatic ring system substituted by a hydroxyl functional group —OH, either by itself or as part of a larger structure. Thus, an aromatic alcohol refers to any aryl, heteroaryl, arylene, and heteroarylene moiety described herein that has a hydroxyl functional group bonded to an aromatic carbon of its aromatic ring system. The aromatic alcohol may be part of a larger moiety if its aromatic ring system is a substituent of this moiety, or may be embedded in a larger moiety by ring fusion and may optionally be substituted as necessary by moieties described herein, including one or more additional hydroxyl substituents. A phenolic alcohol is an aromatic alcohol having a phenol group as the aromatic ring.

[0075] "Aliphatic alcohol" refers to a moiety having non-aromatic carbon atoms bonded to a hydroxyl functional group -OH, either by itself or as part of a larger structure. The carbon atom bearing the hydroxy may be unsubstituted (i.e., methyl alcohol) or may have one, two, or three branched or unbranched alkyl substituents as needed, defining a primary alcohol within a linear or cyclic structure, or a secondary or tertiary aliphatic alcohol. When the alcohol is part of a larger structure, it may be a substituent of that structure by way of a bond through the carbon atom bearing the hydroxy, through the carbon atoms of an alkyl or other moieties described herein to the carbon atom bearing this hydroxyl, or through substituents of this alkyl or other moieties. Aliphatic alcohol contemplates a non-aromatic cyclic structure (i.e., a carbocyclic and heterocarbocyclic ring, optionally substituted), where the hydroxy functional group is bonded to a non-aromatic carbon of the cyclic ring system.

[0076] "Arylalkyl" or "heteroarylalkyl", as used herein, refers to a substituent, moiety or group in which an aryl moiety is bonded to an alkyl moiety, i.e., an aryl-alkyl- in which the aryl and alkyl groups are as described above, e.g., C6H5-CH2- or C6H5-CH(CH3)CH2-. Arylalkyl or heteroarylalkyl is bonded to a larger structure or moiety through the sp 3 carbon of its alkyl moiety.

[0077] As used herein, an "electron withdrawing group" means a functional group or an electronegative atom that pulls electron density from a bonded atom either inductively and / or by resonance (either predominating), i.e., the functional group or atom can be inductively electron withdrawing but overall electron donating by resonance, and has a tendency to stabilize anions or electron-rich moieties. The electron withdrawing effect is usually inductively transmitted to other atoms bonded to the electron-deficient bonded atom by an electron withdrawing group (EWG), even in a weakened form, thus affecting the electrophilicity of more remote reactive centers. Exemplary electron withdrawing groups include, but are not limited to, -C(=O), -CN, -NO2, -CX3, -X, -C(=O)OR ’ , -C(=O)N(R ’ )2, -C(=O)R ’ , -C(=O)X, -S(=O)2R ’ , -S(=O)2OR ’ , -S(=O)2NHR ’ , -S(=O)2N(R ’ )2, -P(=O)(OR ’ )2, -P(=O)(CH3)NHR ’ , -NO, -N(R ’ )3 + wherein X is -F, -Br, -Cl or -I, and R' is, in some embodiments, independently selected at each occurrence from the group consisting of hydrogen and C1-6 alkyl, and certain O-linked moieties described herein such as acyloxy.

[0078] Exemplary EWGs can also include aryl groups (e.g., phenyl) depending on the substitution and certain heteroaryl groups (e.g., pyridine). Thus, the term "electron withdrawing group" also includes aryl or heteroaryl further substituted by an electron withdrawing group. Usually, the electron withdrawing groups on the aryl or heteroaryl are -C(=O), -CN, -NO2, -CX3 and -X, and X independently selected is a halogen, usually -F or -Cl. Depending on those substituents, the alkyl moiety can also be an electron withdrawing group.

[0079] The "leaving group ability" relates to the ability of an alcohol, thiol, amine or amide-containing compound corresponding to camptothecin in a camptothecin conjugate to be released from the conjugate as a free drug after activation of a self-destructive event within the conjugate. That release is , and can vary in the absence of the benefit of the methylene carbamate unit to which the camptothecin is attached (i.e., when the camptothecin is attached directly to the self-destructive moiety and has no intervening methylene carbamate unit). Good leaving groups are typically weak bases, and the higher the acidity of the functional group released from such a conjugate, the weaker its conjugate base. Thus, the leaving group ability of an alcohol, thiol, amine or amide-containing free drug from camptothecin will be related to the pKa of the functional group of the drug released from the conjugate when not using a methylene carbamate unit (i.e., when the camptothecin is attached directly to the self-destructive moiety). Thus, the lower the pKa of that functional group, the greater the leaving group ability. Other factors can also contribute to the release of the free drug from a conjugate that does not have the benefit of the methylene carbamate unit, but generally, a drug having a functional group with a lower pKa value will be a better leaving group than a drug attached via a functional group having a higher pKa value. Another consideration is that a functional group having too low a pKa value may result in an unacceptable activity profile due to premature loss of camptothecin by spontaneous hydrolysis. In the case of conjugates using a methylene carbamate unit, a common functional group (i.e., carbamic acid) having a pKa value that allows for efficient release of the free drug is generated upon self-destruction without undergoing an unacceptable loss of camptothecin.

[0080] As used herein, the "succinimide moiety" refers to an organic moiety containing a succinimide ring system, which usually further contains an alkylene-containing moiety bonded to the imide nitrogen of the ring system and is present in one type of stretcher unit (Z). The succinimide moiety typically results from the Michael addition of the sulfhydryl group of the ligand unit to the maleimide ring system of the stretcher unit precursor (Z'). Thus, the succinimide moiety contains a thio-substituted succinimide ring system and, when present in the camptothecin conjugate, has its imide nitrogen substituted by the remainder of the linker unit of the camptothecin conjugate and is optionally substituted by substituents present on the maleimide ring system of Z'.

[0081] As used herein, the "acid-amide moiety" refers to succinic acid having an amide substituent resulting from the thio-substituted succinimide ring system of the succinimide moiety that undergoes one cleavage of its carbonyl-nitrogen bond upon hydrolysis. Hydrolysis to provide the succinic acid-amide moiety reduces the likelihood that the linker unit will undergo premature loss of the ligand unit to which the linker unit is attached by elimination of the antibody-thio substituent. Hydrolysis of the succinimide ring system of the thio-substituted succinimide moiety is expected to result in regiochemical isomers of the acid-amide moiety due to differences in the reactivity of the two carbonyl carbons of the succinimide ring system that are at least partially attributable to substituents present in the maleimide ring system of the stretcher unit precursor and thio substituents introduced by the targeting ligand.

[0082] As used herein, the term "prodrug" refers to a compound that is less biologically active or inactive and is converted in the body to a more biologically active compound by a chemical or biological process (i.e., a chemical reaction or enzymatic biological conversion). Usually, a biologically active compound is made less biologically active (i.e., converted to a prodrug) by chemically modifying the compound with a prodrug moiety. In some embodiments, the prodrug is a type II prodrug, which is bioactivated extracellularly, e.g., in digestive fluids or in the body's circulatory system, e.g., in blood. Exemplary prodrugs are esters and β-D-glucopyranosides.

[0083] In many instances, the conjugates, linkers, and assemblies of components described herein refer to reactive groups. A "reactive group" or RG is a group that includes a reactive site (RS) capable of forming a bond with either a component of a linker unit (i.e., A, W, Y) or camptothecin D. The RS is the reactive site within the reactive group (RG). Reactive groups include sulfhydryl groups that form disulfide or thioether bonds, aldehyde, ketone, or hydrazine groups that form hydrazone bonds, carboxylic acid or amino groups that form peptide bonds, carboxylic acid or hydroxy groups that form ester bonds, sulfonic acid that forms sulfonamide bonds, alcohol that forms carbamate bonds, and amine that forms sulfonamide or carbamate bonds.

[0084] The following table is an illustration of reactive groups, reaction sites, and exemplary functional groups that can be formed after reaction of the reaction site. This table is not limiting. One of ordinary skill in the art will understand that the portions of R’ and R” specified in the table are any practical organic moieties (e.g., alkyl groups, aryl groups, heteroaryl groups or substituted alkyl, aryl or heteroaryl groups) that are compatible with the bond formation resulting from the conversion of RG to one of the exemplary functional groups. As applied to embodiments of the present invention, it is understood that R’ may in some cases be one or more components of a self-stabilizing linker or an optional secondary linker, and that in some cases R” may be one or more components of an optional secondary linker, camptothecin, a stabilizing unit or a detection unit.

Table 10

[0085] Some embodiments of the present invention are described below, which are in no way intended to limit the present invention, and a more detailed discussion of the components constituting the conjugate follows. One of ordinary skill in the art will understand that each of the specific conjugates and any of their selected embodiments are intended to cover the entire range of each component and linker. Camptothecin conjugate

[0086] In one exemplary embodiment, a camptothecin conjugate having the following formula: L-(Q-D) p or a salt thereof [wherein L is a ligand unit, the subscript p is an integer from 1 to 16, Q is the following: -Z-A-,-Z-A-RL-;-Z-A-RL-Y-;Z-A-S * -W-;-Z-A-S * -RL-;-Z-A-B(S * )-RL-; -Z-A-S * -W-RL-, -Z-A-S * -RL-Y; and -Z-A-B(S * )-RL-Y A linker unit having a formula selected from the group consisting of: wherein Z is a spacer unit, A is a bonding or connector unit, B is a parallel connector unit, S * is a dispenser, W is a peptide unit, RL is a releasable unit, Y is a spacer unit, D is as follows:

Chemical formula

Chemical formula

[0087] (wherein R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)-C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-,

[0088] R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl,

[0089] R F and R F’is each independently selected from the group consisting of -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl, C1-C8 alkyl-C(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkyl-C(O)-, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl-C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl-, or

[0090] R F and R F’ together with the nitrogen atom to which each is attached, form a 5-, 6- or 7-membered ring having 0-3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, and the cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of R B R C R F and R F’ are substituted with 0-3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2) is a drug unit selected from the group consisting of

[0091] The point of attachment of D to Q is such that Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S* ) -RL-, -Z-A-S * -RL-Y or -Z-A-B(S * ) -RL-Y- (where RL is any one of the releasable linkers disclosed herein), through any one heteroatom of the hydroxyl functional group or primary or secondary amine functional group present in CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or

[0092] The bonding point of D to Q is such that Q is -Z-A-, -Z-A-S * -W- or -Z-A-B(S * ) -W-, or when Q is -Z-A-S * -RL-, -Z-A-B(S * ) -RL-, -Z-A-S * -W-RL- or -Z-A-B(S * ) -W-RL- (where RL is a releasable unit other than a glucuronide unit), through the oxygen atom of the hydroxyl group substituent in the lactone ring of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, and

[0093] provided that when the bonding point is to the nitrogen atom of the amino group of CPT6, at least one of R F and R F’ is -H,

[0094] provided that when D is CPT1 having a bond through its amino group, -Z-A-RL-, -Z-A-RL-Y-, -Z A-S * -RL-, -Z-A-B(S * ) -RL-, -Z-A-S * -RL-Y and -Z-A-B(S * ) -RL-Y- the -Z-A- is other than succinimide-caproyl-β-alanyl optionally having a hydrolyzed form of a succinimide ring) is provided herein.

[0095] In one group of embodiments, D has the formula CPT5.

[0096] In one group of embodiments, D has the formula CPT2.

[0097] In one group of embodiments, D has the formula CPT3.

[0098] In one group of embodiments, D has the formula CPT4.

[0099] In one group of embodiments, D has the formula CPT1.

[0100] In one group of embodiments, D has the formula CPT6.

[0101] In one group of embodiments, D has the formula CPT7.

[0102] In one group of embodiments, Q is the following: -Z-A-RL- and -Z-A-RL-Y-

[0103] (wherein RL is a releasable linker that is a glucuronide unit, and the groups Z, A, and Y have the meanings presented above and in any one of the embodiments specifically listed herein). having a formula selected from the group consisting of.

[0104] In one group of embodiments, Q is the following: -Z-A-S * -RL- and -Z-A-S * -RL-Y-

[0105] (wherein RL is a releasable linker that is a glucuronide unit, and the groups Z, A, S * and Y have the meanings presented above and in any one of the embodiments specifically listed herein). having a formula selected from the group consisting of.

[0106] In one group of embodiments, Q is as follows: -Z-A-B(S * )-RL- and -Z-A-B(S * )-RL-Y-

[0107] (wherein RL is a releasable linker that is a glucuronide unit, and the groups Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically listed herein) has a formula selected from the group consisting of

[0108] In another group of embodiments, Q is as follows: -Z-A- or -Z-A-RL-

[0109] (wherein RL is a releasable linker other than a glucuronide unit, and the groups Z and A have the meanings presented above and in any one of the embodiments specifically listed herein) has a formula selected from the group consisting of

[0110] In another group of embodiments, Q is as follows: -Z-A-S * -RL- and -Z-A-B(S * )-RL-

[0111] (wherein RL is a releasable linker other than a glucuronide unit, and the groups Z, A, S * and B have the meanings presented above and in any one of the embodiments specifically listed herein) has a formula selected from the group consisting of

[0112] In another group of embodiments, Q is as follows: -Z-A-S * -W- and -Z-A-B(S * )-W-

[0113] (wherein the groups Z, A, S* 、 B, and W have the meanings presented above and in any one of the embodiments specifically enumerated herein) having a formula selected from the group consisting of

[0114] In another group of embodiments, Q is as follows: -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL-

[0115] (wherein RL is a releasable linker other than a glucuronide unit, and the groups Z, A, S * 、 B, and W have the meanings presented above and in any one of the embodiments specifically enumerated herein) having a formula selected from the group consisting of

[0116] In one group of embodiments, Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y-, and a camptothecin conjugate comprising a drug unit having formula CPT1 has the following formula:

Chemical formula

Chemical formula

[0117] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S *, B, and Y have the meanings presented above and in any one of the embodiments specifically enumerated herein, provided that -Z-A- of the formulas CPT1iN, CPT1iiN, CPT1iiiN, CPT1ivN, CPT1vN, and CPT1viN is other than succinimide-caproyl-β-alanyl optionally having a hydrolyzed form of the succinimide ring) are each represented by

[0118] In other embodiments, Q has the formula -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL-, and a camptothecin conjugate comprising a drug unit having the formula CPT1 has the following formula:

Chemical formula

Chemical formula

[0119] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B, and W have the meanings presented above and in any one of the embodiments specifically enumerated herein) are each represented by

[0120] In another group of embodiments, Q has the formula -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S *)-RL-Y has the formula and contains a drug unit having formula CPT2. The camptothecin conjugate has the following formula: [Chemical Formula]

[0121] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0122] In other embodiments, Q has the formula -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL-. A camptothecin conjugate having the formula and containing a drug unit having formula CPT2 has the following formula: [Chemical Formula]

[0123] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B and W have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0124] In one group of embodiments, R in the formulas CPT2iOa, CPT2iiOa, CPT2iiiOa, CPT2ivOa, CPT2vOa, CPT2viOa, CPT2iOb, CPT2iiOb, CPT2iiiOb, CPT2ivOb, CPT2vOb, CPT2viOb, CPT2viiOb or CPT2viiiOb B is a moiety selected from the group consisting of -H, C1-C8 alkyl and C1-C8 haloalkyl.

[0125] In one group of embodiments, R in the formulas CPT2iOa, CPT2iiOa, CPT2iiiOa, CPT2ivOa, CPT2vOa, CPT2viOa, CPT2iOb, CPT2iiOb, CPT2iiiOb, CPT2ivOb, CPT2vOb, CPT2viOb, CPT2viiOb or CPT2viiiOb B is a moiety selected from the group consisting of C3-C8 cycloalkyl, (C3-C8 cycloalkyl)-C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-, and the cycloalkyl and phenyl moieties of R B are substituted with 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2.

[0126] In another group of embodiments, a camptothecin conjugate, wherein Q has the formula -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y- and contains a drug unit having the formula CPT3, has the following formula:

Chemical formula

Chemical formula

[0127] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically recited herein) are each represented by

[0128] In other embodiments, Q is -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL- and a camptothecin conjugate comprising a drug unit having the formula CPT3 has the following formula:

Chemical Formula

[0129] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B and W have the meanings presented above and in any one of the embodiments specifically recited herein) are each represented by

[0130] In one group of embodiments, R in the formulas CPT3iOa, CPT3iiOa, CPT3iiiOa, CPT3ivOa, CPT3vOa, CPT3viOa, CPT3iO’a, CPT3 iiO’a, CPT3iiiO’a, CPT3ivO’a, CPT3vO’a, CPT3viO’a, CPT3iOb, CPT3iiOb, CPT3iiiOb, CPT3ivOb, CPT3vOb, CPT3viOb, CPT3viiOb or CPT3viiiOb C is C1-C6 alkyl.

[0131] In one group of embodiments, R in the formulas CPT3iOa, CPT3iiOa, CPT3iiiOa, CPT3ivOa, CPT3vOa, CPT3viOa, CPT3iO’a, CPT3iiO’a, CPT3iiiO’a, CPT3ivO’a, CPT3vO’a, CPT3viO’a, CPT3iOb, CPT3iiOb, CPT3iiiOb, CPT3ivOb, CPT3vOb, CPT3viOb, CPT3viiOb or CPT3viiiOb C is C3-C6 cycloalkyl.

[0132] In another group of embodiments, Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y- and a drug unit having the formula CPT4, the camptothecin conjugate is of the following formula: [Chemical formula] [Chemical formula]

[0133] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0134] In other embodiments, Q is -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S* -W-RL- and -Z-A-B(S * ) having the formula -W-RL- and containing a drug unit having the formula CPT4, a camptothecin conjugate has the following formula:

Chemical formula

Chemical formula

[0135] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B and W have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0136] In another group of embodiments, Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y- and having a drug unit having the formula CPT5, a camptothecin conjugate has the following formula:

Chemical formula

Chemical formula

[0137] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0138] In other embodiments, Q has the formula -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL- and a camptothecin conjugate comprising a drug unit having formula CPT5 has the following formula:

Chemical formula

Chemical formula

[0139] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B and W have the meanings presented above and in any one of the embodiments specifically listed herein) are each represented by.

[0140] In another group of embodiments, Q has the formula -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y- and a camptothecin conjugate comprising a drug unit having formula CPT6 has the following formula:

Chemical formula

Chemical formula

[0141] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S* 、 B, and Y have the meanings presented above and in any of the embodiments specifically enumerated herein) are each represented by

[0142] In other embodiments, Q is -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL- and a drug unit having formula CPT6, the camptothecin conjugate has the following formula:

Chemical formula

Chemical formula

[0143] (wherein RL is a releasable linker other than a glucuronide unit, and the groups L, Z, A, S * , B, and W have the meanings presented above and in any one of the embodiments specifically enumerated herein) are each represented by

[0144] In one group of embodiments, R in formula CPT6iN, CPT6iiN, CPT6iiiN, CPT6ivN, CPT6vN or CPT6viN F is -H.

[0145] In one group of embodiments, R in formula CPT6iOa, CPT6iiOa, CPT6iiiOa, CPT6ivOa, CPT6vOa, CPT6viOa, CPT6iOb, CPT6iiOb, CPT6iiiOb, CPT6ivOb, CPT6vOb, CPT6viOb, CPT6viiOb or CPT6viiiOb F and RF’ In both cases, it is -H.

[0146] In one group of embodiments, R in the formula CPT6iN, CPT6iiN, CPT6iiiN, CPT6ivN, CPT6vN or CPT6viN F is a moiety selected from the group consisting of C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkyl-C(O)-, C1-C8 hydroxyalkyl-C(O)-, and C1-C8 aminoalkyl C(O)-.

[0147] In one group of embodiments, R in the formula CPT6iN, CPT6iiN, CPT6iiiN, CPT6ivN, CPT6vN or CPT6viN F is C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl-, and the cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of R F are substituted with 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2.

[0148] In one group of embodiments, R in the formula CPT6iN, CPT6iiN, CPT6iiiN, CPT6ivN, CPT6vN or CPT6viN F is -H, C3-C10 Cycloalkyl, (C3-C 10 Cycloalkyl)-C1-C4 alkyl-, C3-C 10 Heterocycloalkyl, (C3-C 10 Heterocycloalkyl)-C1-C4 alkyl, phenyl, phenyl-C1-C4 alkyl-, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl-C1-C4 alkyl- independently selected from the group consisting of a moiety, R F The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of are substituted with 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2.

[0149] In one group of embodiments, R in the formulas CPT6iOa, CPT6iiOa, CPT6iiiOa, CPT6ivOa, CPT6vOa, CPT6viOa, CPT6iOb, CPT6iiOb, CPT6iiiOb, CPT6ivOb, CPT6vOb, CPT6viOb, CPT6viiOb or CPT6viiiOb F and R F’ both combine with the nitrogen atom to which they are attached to form a 5-membered, 6-membered or 7-membered ring having 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2.

[0150] In one group of embodiments, R in the formulas CPT6iOa, CPT6iiOa, CPT6iiiOa, CPT6ivOa, CPT6vOa, CPT6viOa, CPT6iOb, CPT6iiOb, CPT6iiiOb, CPT6ivOb, CPT6vOb, CPT6viOb, CPT6viiOb or CPT6viiiOb F and R F’At least one of them is a moiety independently selected from the group consisting of C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl(hydoxyalkyl)-C(O)- and C1-C8 aminoalkyl-C(O)- is a moiety independently selected from the group consisting of -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkyl-C(O)-, C1-C8 hydroxyalkyl-C(O)-, and C1-C8 aminoalkylC(O)-.

[0151] In one group of embodiments, R in formula CPT6iO, CPT6iiO, CPT6iiiO, CPT6ivO, CPT6vO or CPT6viO F and R F’ are each a moiety independently selected from the group consisting of C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl, C1-C8 alkyl-C(O)-, C1-C8 hydroxyalkyl-C(O)-, and C1-C8 aminoalkyl-C(O)-.

[0152] In one group of embodiments, R in the formulas CPT6iO, CPT6iiO, CPT6iiiO, CPT6ivO, CPT6vO or CPT6viO F and R F’ at least one of which is selected independently from the group consisting of C3-C 10 cycloalkyl, C3-C 10 cycloalkyl-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl-C1-C4 alkyl-, and the cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of R F and R F’ are substituted by 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, and the other is selected from the group consisting of -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkyl-C(O)-, C1-C8 hydroxyalkyl-C(O)-, and C1-C8 aminoalkyl C(O)-)2.

[0153] In one group of embodiments, R in the formulas CPT6iO, CPT6iiO, CPT6iiiO, CPT6ivO, CPT6vO or CPT6viO F and R F’ at least one of which is selected independently from the group consisting of C3-C 10 cycloalkyl, C3-C 10 cycloalkyl-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10a moiety independently selected from the group consisting of (heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl-C1-C4 alkyl-, and the other is -H, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl- is a moiety selected from the group consisting of, R F and R F’ The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of are independently substituted by 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2.

[0154] In one group of embodiments, R in the formulas CPT6iO, CPT6iiO, CPT6iiiO, CPT6ivO, CPT6vO or CPT6viO F and R F’ are each, -H, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl- is a moiety independently selected from the group consisting of, R F and R F’The cycloalkyl, heterocycloalkyl, phenyl, and heteroaryl moieties are independently substituted with 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl, and -N(C1-C4 alkyl)2.

[0155] In another group of embodiments, Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-S * -RL-Y-, -Z-A-B(S * )-RL- or -Z-A-B(S * )-RL-Y-, and a camptothecin conjugate comprising a drug unit having Formula CPT7 has the following formula: [Chemical formula] [Chemical formula]

[0156] (wherein RL is any one of the releasable linkers disclosed herein, preferably RL is a glucuronide unit, and the groups L, Z, A, S * , B and Y have the meanings presented above and in any one of the embodiments specifically recited herein) are each represented by.

[0157] In other embodiments, Q is -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL-, and a camptothecin conjugate comprising a drug unit having Formula CPT5 has the following formula: [Chemistry] [Chemistry]

[0158] (In the formula, RL is a releasable linker other than the glucuronide unit, and the groups L, Z, A, S * , B, and W have the meanings presented above and in any one of the embodiments specifically listed herein.) Each is represented by Camptothecin-linker compound

[0159] In some embodiments, when preparing a camptothecin conjugate, it may be desirable to synthesize the complete drug-linker combination before conjugating to the targeting agent. In such embodiments, the camptothecin-linker compounds described herein are intermediate compounds. In those embodiments, the stretcher units in the camptothecin-linker compounds are not yet covalently bound to the ligand units (i.e., are Z', the stretcher unit precursors), and thus have functional groups for conjugating to the targeting ligand. In one embodiment, the camptothecin-linker compound comprises a camptothecin compound (shown herein as formulas CPT1, CPT2, CPT3, CPT4, CPT5, CPT6, and CPT7), and a linker unit (Q) comprising a glucuronide unit as the releasable linker (RL), through which the ligand unit is bound to the camptothecin.

[0160] In another embodiment, the camptothecin-linker compound comprises a camptothecin compound of formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, and a linker unit (Q) comprising a releasable linker (RL) other than a glucuronide unit, through which a Ligand unit is attached to the conjugated camptothecin compound. Thus, in any embodiment, the linker unit comprises, in addition to RL, a Stretcher unit precursor (Z') which comprises a functional group for conjugating to a targeting agent which is a precursor to the Ligand unit, thus allowing RL to be attached (directly or indirectly) to the Ligand unit. In some of these embodiments, the parallel connector unit (B) comprises a partitioning agent (S) as a side chain appendage. * It is recommended to add In any one of those embodiments, the connector unit (A) is present when it is desirable to impart a longer distance between the stretcher unit and the RL.

[0161] In one group of embodiments, the camptothecin-linker compounds include camptothecin compounds having the formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7 and a linker unit (Q), where Q is any one of the linker units (i.e., A, S, * and / or B(S * )) via binding to the intervening component , a releasable linker (RL) that is a glucuronide unit attached directly to a Stretcher unit precursor (Z') or indirectly to Z', where Z' contains a functional group capable of forming a covalent bond to a targeting agent.

[0162] In another group of embodiments, the camptothecin-linker compound comprises a camptothecin having the formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7 and a linker unit (Q), where Q is a linker unit (i.e., A, S, * and / or B(S *Including a releasable linker (RL) other than the glucuronide unit (RL), directly or indirectly linked to the stretcher unit precursor (Z') via a bond to an intervening component of )), where Z' includes a functional group capable of forming a covalent bond to the targeting agent.

[0163] In the context of camptothecin conjugates and / or camptothecin-linker compounds, the assembly is best described in relation to the group of its components. Some procedures are also described herein, but the order of assembly and general conditions for preparing the conjugates and compounds will be well understood by those skilled in the art. Group of components Ligand unit:

[0164] In some embodiments of the present invention, a ligand unit is present. The ligand unit (L-) is a targeting agent that specifically binds to a target moiety. In one group of embodiments, the ligand unit binds specifically and selectively to a cell component (cell binding agent) or another target molecule of interest. The ligand unit acts to target and present camptothecin (CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7) to a specific population of target cells with which the ligand unit interacts due to the presence of its targeting component or molecule, and enables the subsequent release of the free drug within or in the vicinity of the target cell (i.e., intracellularly or extracellularly). L, which is a ligand unit, includes, but is not limited to, proteins, polypeptides and peptides. Suitable ligand units include, for example, antibodies, such as full-length antibodies and antigen-binding fragments thereof, interferons, lymphokines, hormones, growth factors, and colony-stimulating factors, vitamins, nutrient transport molecules (including, but not limited to, transferrin, etc.), or any other cell-binding molecule or substance. In some embodiments, the ligand unit (L) is derived from an antibody or non-antibody protein targeting agent.

[0165] In one group of embodiments, the ligand unit is attached to Q (linker unit) containing a glucuronide releasable linker. As noted above, additional linking components are present in the conjugates described herein, providing additional space between the camptothecin drug compound and the ligand unit (e.g., a spacer unit and optionally a connector unit, A) for purpose, or imparting properties to the composition that increase solubility (e.g., a partitioning agent S * ) can serve its purpose. In some such embodiments, the ligand unit is attached to Z of the linker unit via a heteroatom of the ligand unit. Heteroatoms that can be present on the ligand unit for such attachment include sulfur (derived from the sulfhydryl group of the targeting ligand in one embodiment), oxygen (derived from the carboxyl or hydroxyl group of the targeting ligand in one embodiment), and optionally substituted nitrogen (derived from the primary or secondary amine functionality of the targeting ligand in one embodiment, or in another embodiment, from an optionally substituted amide nitrogen). Those heteroatoms can be present in the native state of the ligand, e.g., in a targeting ligand in a naturally occurring antibody, or can be introduced into the targeting ligand by chemical modification or biological manipulation.

[0166] In one embodiment, the targeting agent, which is a precursor to the ligand unit, has a sulfhydryl functionality and as a result, the ligand unit is attached to the linker unit via the sulfur atom of the sulfhydryl functionality.

[0167] In another embodiment, the targeting agent, which is a precursor to the ligand unit, has one or more lysine residues capable of reacting with an activated ester of a spacer unit precursor of a camptothecin-linker compound intermediate (such esters include, but are not limited to, N-hydroxysuccimide, pentafluorophenyl and p-nitrophenyl esters), thus providing an amide bond consisting of the nitrogen atom of the ligand unit and the C=O group of the spacer unit of the linker unit.

[0168] In yet another aspect, the targeting agent, which is a precursor to the ligand unit, has one or more lysine residues that are capable of chemical modification to introduce one or more sulfhydryl groups. In those embodiments, the ligand unit is covalently attached to the linker unit by the sulfur atom of the sulfhydryl functional group. Reagents that can be used to modify lysine in such a manner include, but are not limited to, N-succinimidyl S-acetylthioacetate (SATA) and 2-iminothiolane hydrochloride (Traut's reagent).

[0169] In another embodiment, the targeting agent, which is a precursor to the ligand unit, has one or more carbohydrate groups that are capable of modification to provide one or more sulfhydryl functional groups. The chemically modified ligand unit in the camptothecin conjugate is attached to a linker unit component (e.g., a stretcher unit) via the sulfur atom of the sulfhydryl functional group.

[0170] In yet another embodiment, the targeting agent, which is a precursor to the ligand unit, has one or more carbohydrate groups that can be oxidized to provide an aldehyde (-CHO) functional group (see, e.g., Laguzza, et al., 1989, J. Med. Chem. 32(3):548-55). In these embodiments, the corresponding aldehyde interacts with a reactive site on the stretcher unit precursor to form a bond between the stretcher unit and the ligand unit. Reactive sites on the stretcher unit precursor that are capable of interacting with the reactive carbonyl-containing functional group on the targeted ligand unit include, but are not limited to, hydrazine and hydroxylamine. Other protocols for modifying proteins to attach a linker unit (Q) or related chemical species are described in Coligan et al., Current Protocols in Protein Science, vol. 2, Described in John Wiley & Sons (2002) (incorporated herein by reference). ).

[0171] In some embodiments, the targeting agent, which is a precursor to the ligand unit t, can form a bond by interacting with a reactive functional group on the stretcher unit precursor (Z’) to form a covalent bond between the stretcher unit (Z) and the ligand unit that structurally corresponds to the targeting agent. The functional group of Z’ that has such an ability to interact with the targeting agent will depend on the nature of the targeting agent that structurally corresponds to the ligand unit. In some embodiments, the reactive group is a maleimide present on the stretcher unit prior to that bond that forms the ligand unit (i.e., the maleimide moiety of the stretcher unit precursor). The covalent bond of the ligand unit to the stretcher unit is achieved via a sulfhydryl functional group of the targeting agent that is a precursor to the ligand unit and that interacts with the maleimide functional group of Z’, forming a thio-substituted succinimide. The sulfhydryl functional group can be present in the native state of the targeting agent, e.g., in the targeting agent in a naturally occurring residue, or can be introduced into the targeting agent by chemical modification or biological manipulation.

[0172] In yet another embodiment, the ligand unit is derived from an antibody and the sulfhydryl group is generated by reduction of the interchain disulfide of the antibody. Thus, in some embodiments, the linker unit is conjugated to a cysteine residue derived from the reduced interchain disulfide.

[0173] In yet another embodiment, the ligand unit is derived from an antibody and the sulfhydryl functional group is chemically introduced into the antibody, e.g., by introduction of a cysteine residue. Thus, in some embodiments, the linker unit (with or without the attached camptothecin) is conjugated to the ligand unit by the introduced cysteine residue of the ligand unit.

[0174] ​In the case of bioconjugates, the site of drug conjugation can affect several parameters, including the ease of conjugation, the stability of the drug-linker, the effect on the biophysical properties of the resulting bioconjugate, and the cytotoxicity in vitro. With regard to drug-linker stability, the site of conjugation of the drug-linker moiety to the ligand unit can affect the ability of the conjugated drug-linker moiety to undergo a cleavage reaction, and in some instances, may cause premature release of the free drug. Sites for conjugation on the targeting agent include, for example, reduced interchain disulfides and cysteine residues selected at engineered sites. In some embodiments, the conjugation method for forming the camptothecin conjugates described herein uses a thiol residue at a genetically engineered site (e.g., position 239 according to the EU index described by Kabat) that is less susceptible to cleavage reactions compared to conjugation methods using thiol residues from reduced disulfide bonds. In other embodiments, the conjugation method for forming the camptothecin conjugates described herein uses a thiol residue resulting from the reduction of an interchain disulfide bond.

[0175] In some embodiments, the camptothecin conjugate includes, as its ligand unit, a non-immunoreactive protein, polypeptide, or peptide. Thus, in some embodiments, the ligand unit is derived from a non-immunoreactive protein, polypeptide, or peptide. Examples include, but are not limited to, transferrin, epidermal growth factor ("EGF"), bombesin, gastrin, gastrin-releasing peptide, platelet-derived growth factor, IL-2, IL-6, transforming growth factor ("TGF") (such as TGF-α and TGF-β), vaccinia growth factor ("VGF"), insulin, and insulin-like growth factors I and II, somatostatin, lectin, and apolipoproteins derived from low density lipoprotein.

[0176] Particularly preferred ligand units are derived from antibodies. Thus, in any one of the embodiments described herein, the ligand unit is derived from an antibody. Useful polyclonal antibodies are heterogeneous populations of antibody molecules derived from the sera of immunized animals. Useful monoclonal antibodies are homogeneous populations of antibodies to specific antigenic determinants (e.g., cancer cell antigens, viral antigens, microbial antigens, proteins, peptides, carbohydrates, chemicals, nucleic acids, or fragments thereof). Monoclonal antibodies (mAbs) to the antigen of interest are, in some embodiments, prepared by using any technique known in the art that results in the production of antibody molecules by a continuous cell line in culture.

[0177] Useful monoclonal antibodies include, but are not limited to, human monoclonal antibodies, humanized monoclonal antibodies, or chimeric human-mouse (or other species) monoclonal antibodies. Antibodies include full-length antibodies and antigen-binding fragments thereof. Human monoclonal antibodies can be made by any of a number of 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).

[0178] Antibodies useful for practicing the present invention are intact antibodies, or functionally active fragments, derivatives or analogs of the antibodies, and the antibodies or fragments thereof are capable of immunospecific binding to a target cell (e.g., a cancer cell antigen, a viral antigen or a microbial antigen), or to another antibody bound to a tumor cell or matrix. In this regard, "functionally active" means that the fragment, derivative or analog is capable of immunospecifically binding to the target cell. To determine which CDR sequences bind to the antigen, in some embodiments, synthetic peptides containing the CDR sequences are used in binding assays with the antigen by binding assay methods known in the art (e.g., BIAcore assay) (see, for example, Kabat et al., 1991, Sequences of Proteins of Immunological Interest,FifthEdition, National Institute of Health, Bethesda, Md;Kabat E et al., 1980,J.Immunology 125(3):961-969).

[0179] Other useful antibodies include, but are not limited to, antibody fragments such as F(ab’)2 fragments, Fab fragments, Fvs, single-chain antibodies, diabodies, triabodies, tetra-bodies, scFv, scFv-FV, or any other molecule having the same specificity as the antibody.

[0180] Furthermore, in some embodiments, recombinant antibodies such as chimeric and humanized monoclonal antibodies that contain both human and non-human portions made using standard recombinant DNA techniques are useful antibodies. Chimeric antibodies are molecules in which different portions are derived from different animal species, such as those having variable regions derived from, for example, 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 derived from non-human species that have one or more complementarity determining regions (CDRs) derived from a non-human species and framework regions derived from human immunoglobulin molecules (see, e.g., U.S. Patent No. 5,585,089, which is incorporated herein by reference in its entirety). Such chimeric monoclonal antibodies and humanized monoclonal antibodies are, in some embodiments, described, for example, in International Publication No. WO87 / 02671; European Patent Publication No. 0184187; European Patent Publication No. 0171496; European Patent Publication No. 0173494; International Publication No. WO86 / 01533; U.S. Patent No. 4,816,567; Berter et al., Science (1988) 240: 1041-1043; Liu et al., Proc. Nat'l. Acad. Sci. USA (1987) 84:3439-3443; Liu et al., J. Immunol. (1987) 139:3521-3526; Sun et al., Proc. Natl. Acad. Sci. USA (1987) 84: 214-218; Nishimura et al., Cancer. Res. (1987) 47:999-1005; Wood et al., Nature (1985) 314:446-449; Shaw et al., J. Natl. CancerInst. (1988) 80: 1553-1559; Morrison, Science (1985) 229: 1202-1207; Oi et al., BioTechniques (1986) 4: 214-221; U.S. Patent No. 5,225,539; Jones et al., Nature (1986) 321: 552-525; Verhoeyan et al., Science (1988) 239: 1534-1536; and Beidler et al., J. Immunol. (1988) 141: 4053-4060 are generated by recombinant DNA techniques known in the art that use the methods described in these references.

[0181] In some instances, fully human antibodies (e.g., where immunogenicity to non-human or chimeric antibodies may occur) are more desirable, and in some embodiments, are generated using transgenic mice that are unable to express endogenous immunoglobulin heavy and light chain genes, but are able to express human heavy and light chain genes.

[0182] Antibodies include analogs and derivatives modified by any means, i.e., such covalent attachment to any type of molecule, so long as the antibody retains its antigen-binding immunospecificity by covalent attachment. For example, but not limited to, antibody derivatives and analogs include, e.g., glycosylation, acetylation, PEGylation, phosphorylation, amidation, derivatization by known protecting / blocking groups, proteolytic cleavage, and the antibody unit of the cell or Including those that are further modified, such as by conjugation to other proteins. In some embodiments, one or more of these numerous chemical modifications are carried out by known techniques including, but not limited to, specific chemical cleavage, acetylation, formylation, metabolic synthesis in the presence of tunicaamycin, etc. In other embodiments, an antibody analog or derivative contains one or more non-natural amino acids, sometimes in combination with one or more of the above chemical modifications.

[0183] In some embodiments, the antibody has one or more modifications (e.g., substitutions, deletions or additions) in the amino acid residues that interact with the Fc receptor. These include modifications in amino acid residues that have been identified as being involved in the interaction between the anti-Fc domain and the FcRn receptor (see, for example, International Publication No. WO97 / 34631, which is hereby incorporated by reference in its entirety).

[0184] In some embodiments, an antibody immunospecific for a cancer cell antigen is commercially available or is produced by methods known to those of skill in the art, such as recombinant expression techniques. A nucleotide sequence encoding an antibody immunospecific for a cancer cell antigen can sometimes be obtained from, for example, the GenBank database, or a similar database, published literature, or by standard cloning and sequencing.

[0185] In a specific embodiment, a known antibody for treating cancer is used.

[0186] In another specific embodiment, an antibody for treating an autoimmune disease is used by the compositions and methods of the present invention.

[0187] In certain embodiments, useful antibodies bind to a receptor or receptor complex expressed on activated lymphocytes. Such receptors or receptor complexes are, in some embodiments, members of the immunoglobulin gene superfamily, TNF receptor superfamily members, integrins, cytokine receptors, chemokine receptors, major histocompatibility proteins, lectins or complement regulatory proteins.

[0188] In some embodiments, the antibody incorporated into the camptothecin conjugate specifically binds to CD19, CD30, CD33, CD70 or LIV-1. Camptothecin compounds:

[0189] The camptothecin compounds utilized in the various embodiments described herein have the following formula:

Chemical formula

Chemical formula

[0190] (wherein R B is a moiety selected from the group consisting of -H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)-C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-,

[0191] R C is a moiety selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl,

[0192] R F and R F’is each independently selected from the group consisting of -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkyl-C(O)-, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenylC1-C4 alkyl, heteroaryl and heteroaryl-C1-C4 alkyl, or

[0193] R F and R F’ together with the nitrogen atom to which both are attached form a 5-, 6- or 7-membered ring having 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and N(C1-C4 alkyl)2,

[0194] R B , R C , R F and R F’ cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties are substituted by 0 to 3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2) is represented by

[0195] In the context of the camptothecin conjugates and camptothecin linker compounds described herein, further other camptothecin compounds useful are the camptothecin compounds 14a - 14z of Table I, and the compounds 18a - 18r of Table J, and camptothecin compounds having a 5 - or 6 - ring fused framework analog to the structures presented as formulas CPT1, CPT2, CPT3, CPT4, CPT5, CPT6, CPT7, 14a - 14z and 18a - 18r, and in some embodiments, the above structures include, but are not limited to, hydroxyl, thiol, amine or amide functional groups, wherein their oxygen, sulfur or optionally substituted nitrogen atoms can be incorporated into the linker and can be released from the camptothecin conjugate as a free drug, and having additional groups including hydroxyl, thiol, amine or amide functional groups. In some embodiments, such functional groups provide only at the site on the camptothecin compound available for attachment to the linker unit (Q). The resulting drug - linker moiety of the camptothecin conjugate is capable of releasing an active free drug at the site targeted by its ligand unit to exert a cytotoxic, cytostatic or immunosuppressive effect.

[0196] "Free drug" refers to the drug present when released from one end of the drug - linker moiety. In some embodiments, the free drug includes fragments of the cleavable linker or spacer unit (Y) groups. The free drug containing fragments of the cleavable linker or spacer unit (Y) is released from the remainder of the drug - linker moiety by cleavage of the cleavable linker or by cleavage of a bond in the group of the spacer unit (Y) and becomes biologically active after release. In some embodiments, the free drug is different from the conjugated drug in that the functional group of the free drug for attachment to the self - destructing assembly unit is no longer bonded (except for the previously shared heteroatom) to a component of the camptothecin conjugate. For example, the free hydroxyl functional group of an alcohol - containing drug can be represented as D - O * H while in the conjugated form, O *The oxygen heteroatom represented by is incorporated into the methylene carbamate unit of the self-destructive unit. During the activation of the self-destructive moiety and the release of the free drug, the covalent bond to O * is replaced by a hydrogen atom, and as a result, the oxygen heteroatom represented by O * is present in the free drug as -O-H. Linker unit (Q)

[0197] As described above, in some embodiments, the linker unit Q is as follows: -Z-A-RL-; -Z-A-RL-Y-; -Z-A-S * -RL-; -Z-A-B(S * )-RL-; -Z-A-S * -RL-Y-; and -Z-A-B(S * )-RL-Y-

[0198] (wherein Z is a stretcher unit, A is a linker or connector unit, B is a branching unit, S * is a dispenser, RL is a releasable linker that is a glucuronide unit, Y is a spacer unit,

[0199] The point of attachment of D to Q is via any one of the hydroxyl, as well as primary and secondary amine hetero atoms present in any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or compounds 14a - 14z of Table I, and compounds 18a - 18r of Table J) and has a formula selected from the group consisting of.

[0200] In other embodiments, the linker unit Q is as follows: -Z-A-; -Z-A-RL-; -Z-A-S * -W-; -Z-A-B(S * )-W-; -Z-A-S * -RL-; -Z-A-B(S * )-RL-; -Z-A-S *-W-RL-; and -Z-A-B(S * )-W-RL-

[0201] (wherein Z is a stretcher unit, A is a linker or connector unit, B is a parallel connector unit, S * is a dispenser, RL is a releasable linker other than a glucuronide unit, W is an amino acid unit,

[0202] The point of attachment to Q is via the hydroxyl group substituent of any one of the lactone rings of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or compounds 14a - 14z of Table I, and compounds 18a - 18r of Table J) has a formula selected from the group consisting of

[0203] In one group of embodiments, Q is: -Z-A-S * -RL- and -Z-A-S * -RL-Y- having a formula selected from the group consisting of

[0204] In another group of embodiments, Q is: -Z-A-B(S * )-RL- and -Z-A-B(S * )-RL-Y- having a formula selected from the group consisting of

[0205] In yet another group of embodiments, Q is: -Z-A-RL- and -Z-A-RL-Y- having a formula selected from the group consisting of Stretcher unit (Z) or (Z'):

[0206] The stretcher unit (Z) is a component of a camptothecin conjugate or a camptothecin-linker compound, or another intermediate that serves to attach a ligand unit to the remainder of the conjugate. In that regard, the stretcher unit precursor (i.e., Z') prior to attachment to the ligand unit has a functional group capable of forming a bond with a functional group of the targeting ligand.

[0207] In some embodiments, the stretcher unit precursor (Z’) has an electrophilic group capable of interacting with a reactive nucleophilic group present on a ligand unit (e.g., an antibody), resulting in a covalent bond between the ligand unit and the stretcher unit of the linker unit. Nucleophilic groups on the antibody having such ability include, but are not limited to, sulfhydryl, hydroxyl, and amino functional groups. The heteroatom of the nucleophilic group of the antibody is reactive with the electrophilic group on the stretcher unit precursor, resulting in a covalent bond between the ligand unit and the linker unit or the stretcher unit of the drug-linker moiety. Useful electrophilic groups for that purpose include, but are not limited to, maleimide, haloacetamide groups, and NHS esters. The electrophilic group provides a convenient site for antibody conjugation to form a camptothecin conjugate or a ligand unit-linker intermediate.

[0208] In other embodiments, the stretcher unit precursor has a reactive site with a nucleophilic group that is reactive with an electrophilic group present on a ligand unit (e.g., an antibody). Useful electrophilic groups on the antibody for that purpose include, but are not limited to, aldehyde and ketone carbonyl groups. The heteroatom of the nucleophilic group of the stretcher unit precursor can react with the electrophilic group on the antibody to form a covalent bond to the antibody. Useful nucleophilic groups on the stretcher unit precursor for that purpose include, but are not limited to, hydrazide, hydro xylamine, amino, hydrazine, thiosemicarbazone, hydrazine carboxylate, and aryl hydrazide. The electrophilic group on the antibody provides a convenient site for antibody conjugation to form a camptothecin conjugate or a ligand unit-linker intermediate.

[0209] In some embodiments, the sulfur atom of the ligand unit is bonded to the succinimide ring system of the stretcher unit formed by the reaction of the thiol functional group of the targeting ligand with the maleimide moiety of the stretcher unit precursor. In other embodiments, the thiol functional group of the ligand unit reacts with an alpha haloacetamide moiety to effect nucleophilic substitution of its halogen substituent, resulting in a stretcher unit with sulfur bonded thereto.

[0210] A representative stretcher unit of such an embodiment has the following structure:

Chemical formula

[0211] (wherein, R 17 The wavy line adjacent to represents a bond to a parallel connector unit (B), or in the absence of B, a bond to a connector unit (A), or in the absence of B, a bond to a distributor (S * ), and the other wavy line represents a covalent bond to the sulfur atom of the ligand unit, and R 17 is -C1 to C 10 alkylene-, C1 to C 10 heteroalkylene-, -C3 to C8 carbocyclo-, -O-(C1 to C8 alkylene)-, -arylene-, -C1 to C 10 alkylene-arylene-, -arylene-C1 to C 10 alkylene-, -C1 to C 10 alkylene-(C3 to C8 carbocyclo)-, -(C3 to C8 carbocyclo)-C1 to C 10 alkylene-, -C3 to C8 heterocyclo-, -C1 to C 10 alkylene-(C3 to C8 heterocyclo)-, -(C3 to C8 heterocyclo)-C1 to C 10 alkylene-, -C1 to C 10 alkylene-C(=O)-, C1 to C 10 heteroalkylene-C(=O)-, -C3 to C8 carbocyclo-C(=O)-, -O-(C1 to C8 alkylene)-C(=O)-, -arylene-C(=O)-, -C1 to C 10Alkylene-arylene-C(=O)-, -arylene-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-C(=O)-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-C(=O)-, -C3-C8 heterocyclo-C(=O)-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-C(=O)-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-NH-, -C1-C 10 Heteroalkylene-NH-, -C3-C8 carbocyclo-NH-, -O-(C1-C8 alkylene)-NH-, -arylene-NH-, -C1-C 10 Alkylene-arylene-NH-, -arylene-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-NH-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-NH-, -C3-C8 heterocyclo-NH-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-NH-, -(C3-C8 heterocyclo lo)-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-S-, C1-C 10 Heteroalkylene-S-, -C3-C8 carbocyclo-S-, -O-(C1-C8 alkylene)-S-, -arylene-S-, -C1-C 10 Alkylene-arylene-S-, -arylene-C1-C 10 Alkylene-S-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-S-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-S-, -C3-C8 heterocyclo-S-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-S- or -(C3-C8 heterocyclo)-C1-C 10 is alkylene-S-) including those having

[0212] In some embodiments, R 17 groups are optionally substituted by basic units (BUs) such as aminoalkyl moieties, e.g., -(CH2) x NH2, -(CH2) x NHR a and -(CH2) x NR a 2 etc., where the subscript x is an integer from 1 to 4, and each R a is independently selected from the group consisting of C1-6 alkyl and C1-6 haloalkyl, or two R a groups together with the nitrogen to which they are attached form an azetidinyl, pyrrolidinyl or piperidinyl group.

[0213] Exemplary stretcher units are of the formula Za or Zb-BU, wherein R 17 is -C1-C 10 alkylene-C(=O)-, -C1-C 10 heteroalkylene-C(=O)-, -C3-C8 carbocyclo-C(=O)-, -O-(C1-C8 alkylene)-C(=O)-, -arylene-C(=O)-, -C1-C 10 alkylene-arylene-C(=O)-, -arylene-C1-C 10 alkylene-C(=O)-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-C(=O)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-C(=O)-, -C3-C8 heterocyclo-C(=O)-, -C1-C 10 alkylene-(C3-C8 heterocyclo)-C(=O)- or -(C3-C8 heterocyclo)-C1-C 10 alkylene-C(=O)-.

[0214] Thus, some preferred embodiments are of the formula Za and Za-BU:

Chemical formula

[0215] (In the formula, the wavy line adjacent to the carbonyl carbon atom indicates B, A or S in the above formula according to the presence or absence of A and / or B * a bond to, and the other wavy line indicates a covalent bond of the succinimide ring carbon atom to the sulfur atom of the ligand unit. During synthesis, the basic amino functional group of the basic unit ( BU) can be protected by a protecting group) is represented by

[0216] More preferred embodiments of the stretcher units of formula Za and Za-BU are as follows:

Chemical formula

[0217] (In the formula, the wavy line adjacent to the carbonyl carbon atom indicates B, A or S in the above formula according to the presence or absence of A and / or B * a bond to, and the other wavy line indicates a covalent bond of the succinimide ring carbon atom to the sulfur atom of the ligand unit).

[0218] It is understood that the ligand unit-substituted succinimides may exist in a hydrolyzed form. Those forms are exemplified below with respect to the hydrolysis of Za or Za-BU, and the structures representing the positional isomers from that hydrolysis have formulas Zb and Zc or Zb-BU and Zc-BU.

[0219] Thus, in another preferred embodiment, the stretcher unit (Z) is as follows:

Chemical formula

[0220] (wherein R 17The wavy lines adjacent to the carbonyl carbon atom bonded to and the wavy lines adjacent to the carbon atoms of the acid-amide moiety are as defined for Za or Za-BU, depending on the presence or absence of A and / or B, and R 17 is -C1-C5 alkylene-, and the alkylene in Zb-BU and Zc-BU is substituted by a basic unit (BU), and BU is -(CH2) x NH2, -(CH2) x NHR a or -(CH 2)x N(R a )2, where the subscript x is an integer from 1 to 4, and each R a is independently selected from the group consisting of C1-6 alkyl and C1-6 haloalkyl, or both R a together with the nitrogen to which they are attached define an azetidinyl, pyrrolidinyl or piperidinyl group) contains a succinic-amide moiety represented by

[0221] In a more preferred embodiment, -Z-A- is a moiety derived from a maleimide-alkanoic acid moiety, or contains an mDPR moiety. See, for example, WO2013 / 173337. In one group of embodiments, Z-A- is derived from a maleimide-propionyl moiety.

[0222] Thus, in some of their more preferred embodiments, the stretcher unit (Z) is a succinic-amide moiety represented by the structure of the formula Zb’, Zc’, (R / S)-Zb’-BU, (S)-Zb’-BU, (R / S)-Zc’-BU or (S)-Zc’-BU as follows:

Chemical formula

[0223] (wherein the wavy lines are as defined for Za or Za-BU) containing.

[0224] In a particularly preferred embodiment, the stretcher unit (Z) is a succinimide moiety represented by the following structure:

Chemical formula

[0225] or a succinic - amide moiety represented by the following structure:

Chemical formula

[0226] Za’, Zb’ or Zc’ (wherein -R of Za, Zb or Zc 17 - is -CH2- or -CH2CH2-), or Za’-BU, Zb’-BU or Zc’-BU (wherein -R of Za-BU, Zb-BU or Zc-BU 17 (BU)- is -CH(CH2NH2)-) is attached to a connector unit (A). Exemplary stretcher units are of the following structure:

Chemical formula

Chemical formula

[0227] (wherein the wavy line is as defined with respect to Za or Za-BU) has.

[0228] Other stretcher units attached to the ligand unit (L) and the connector unit (A) have the above structure, and A in any one of the above -Za-A-, -Za(BU)-A-, -Za’-A-, -Za’(BU)-A-, -Zb-A-, -Zb(BU)-A-, -Zb’-A-, -Zb’(BU)-, -Zc’-A- and Zc’(BU)-A- structures is of the following structure:

Chemical formula

[0229] (wherein the subscript n ranges from 8 to 24, and R PEG is a PEG unit capping group, preferably -CH3 or -CH2CH2CO2H, and the asterisk ( * ) indicates a covalent bond to a stretcher unit corresponding structurally to formula Za, Za’, Zb’ or Zc’, and the wavy line indicates a covalent bond to a releasable linker (RL)) is replaced by a parallel connector unit having

[0230] An exemplary stretcher unit (i.e., stretcher unit precursor) prior to conjugation to the ligand unit contains a maleimide moiety and has the structure of formula Z’a:

Chemical formula

[0231] (wherein the wavy line adjacent to the carbonyl carbon atom indicates a bond to B, A or S in the above formula, depending on the presence or absence of A and / or B, and R * is aminoalkyl optionally substituted, e.g., -(CH2) 17 NH2, -(CH2) x NHR x and -(CH a N(R 2)x )2 etc., is -(CH2) a - optionally substituted by basic units such as, and the subscript x is an integer from 1 to 4, and each R 1~5 is independently selected from the group consisting of C1-6 alkyl and C1-6 haloalkyl, or two R a groups together with the nitrogen to which they are attached form an azetidinyl, pyrrolidinyl or piperidinyl group) a is represented by the structure including .

[0232] Other exemplary stretcher units (i.e., stretcher unit precursors) prior to conjugation to the ligand unit include a maleimide moiety and have the structure of formula Z’a-BU:

Chem.

[0233] (wherein the wavy line adjacent to the carbonyl carbon atom indicates a bond to B, A or S in the above formula, depending on the presence or absence of A and / or B, and R * is aminoalkyl, optionally substituted, for example, -(CH2) 17 NH2, -(CH2) x NHR x and -(CH a substituted by basic units such as -N(R 2)x )2, etc., and the subscript x is an integer from 1 to 4, preferably R a is -CH2- or -CH2CH2-, the subscript x is 1 or 2, and each R 1~5 is independently selected from the group consisting of C1-6 alkyl and C1-6 haloalkyl, or two R 17 groups together with the nitrogen to which they are attached form an azetidinyl, pyrrolidinyl or piperidinyl group) a is represented by the structure including a ).

[0234] In some preferred embodiments of part of formula Z’a, the stretcher unit precursor has the following structure:

Chem.

[0235] (wherein the wavy line adjacent to the carbonyl is as defined for Z’a or Z’a-BU) is represented by one of

[0236] ​In a more preferred embodiment, the stretcher unit precursor (Z’) contains a maleimide moiety and has the following structure: [Chemical formula]

[0237] (wherein the wavy line adjacent to the carbonyl is as defined for Za’, and the amino group is optionally protonated or protected by an amino protecting group) is represented by.

[0238] In the stretcher unit having a BU moiety, it will be understood that the amino functional group of that moiety is usually protected during synthesis by an amino protecting group, such as an acid-labile protecting group (e.g., BOC).

[0239] The structure of Z’a or Z’a-BU (wherein -R 17 - or -R 17 (BU)- is -CH2-, -CH2CH2- or -CH(CH2NH2)-) exemplified stretcher unit precursors covalently bonded to a linker unit containing are of the following structure: [Chemical formula] [Chemical formula]

[0240] (wherein the wavy line adjacent to the carbonyl is as defined for Z’a or Z’a-BU) has.

[0241] Other stretcher unit precursors bonded to the linker unit (A) have the above structure, and A in any one of the above Z’-A- and Z’(BU)-A- structures is of the following structure [Chemical formula]

[0242] (wherein the subscript n ranges from 8 to 24. R PEG is a PEG unit capping group, preferably -CH3 or -CH2CH2CO2H, and the asterisk ( * ) represents a covalent bond to a stretcher unit precursor corresponding structurally to formula Za or Za’, and the wavy line represents a covalent bond to RL) having a parallel connector unit and a dispenser (-B(S * ))-). In examples such as those shown here, the PEG groups shown are intended to be examples of various dispensers, including PEG groups of different lengths and other dispensers that can bind directly to the parallel connector unit or can be modified for binding thereto.

[0243] In another embodiment, the stretcher unit is bonded to the ligand unit via a disulfide bond between the sulfur atom of the ligand unit and the sulfur atom of the stretcher unit. Representative stretcher units of this embodiment are illustrated within the square brackets of formula Zb:

Chemical formula

[0244] (wherein the wavy line represents a bond to a parallel connector unit (B), or to a connector unit (A) if B is absent, or to a dispenser (S * )) if neither A nor B is present, and R 17 is -C1-C 10 alkylene-, C1-C 10 heteroalkylene-, -C3-C8 carbocyclo-, -O-(C1-C8 alkylene)-, -arylene-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-, -C3-C8 heterocyclo-, -C1-C 10Alkylene-(C3-C8 heterocyclo)-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-, -C1-C 10 Alkylene-C(=O)-, C1-C 10 Heteroalkylene-C(=O)-, -C3-C8 carbocyclo-C(=O)-, -O-(C1-C8 alkylene)-C(=O)-, -arylene-C(=O)-, -C1-C 10 Alkylene-arylene-C(=O)-, -arylene-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-C(=O)-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-C(=O)-, -C3-C8 heterocyclo-C(=O)-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-C(=O)-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-NH-, C1-C 10 Heteroalkylene-NH-, -C3-C8 carbocyclo-NH-, -O-(C1-C8 alkylene)-NH-, -arylene-NH-, -C1-C 10 Alkylene-arylene-NH-, -arylene-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-NH-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-NH-, -C3-C8 heterocyclo-NH-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-NH-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-S-, C1-C 10 Heteroalkylene-S-, -C3-C8 carbocyclo-S-, -O-(C1-C8 alkylene)-S-, -arylene-S-, -C1-C 10 Alkylene-arylene-S-, -arylene-C1-C 10 Alkylene-S-, -C1-C 10Alkylene-(C3-C8 carbocyclo)-S-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-S-, -C3-C8 heterocyclo-S-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-S- or -(C3-C8 heterocyclo)-C1-C 10 is alkylene-S-).

[0245] In yet another embodiment, the reactive group of the stretcher unit precursor includes a reactive site capable of forming a bond with a primary or secondary amino group of the ligand unit. Examples of these reactive sites include, but are not limited to, activated esters such as succinimide esters, 4-nitrophenyl esters, pentafluorophenyl esters, tetrafluorophenyl esters, anhydrides, acid chlorides, sulfonyl chlorides, isocyanates and isothiocyanates. Representative stretcher units of this embodiment are shown within the square brackets of Formulas Zci, Zcii and Zciii: [Chemical formula]

[0246] (wherein the wavy line represents a bond to the parallel connector unit (B), or to the connector unit (A) when B is absent, or to the distributor (S * ) when neither A nor B is present, and R 17 is -C1-C 10 alkylene-, C1-C 10 heteroalkylene-, -C3-C8 carbocyclo-, -O-(C1-C8 alkylene)-, -arylene-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-, -C3-C8 heterocyclo-, -C1-C 10 alkylene-(C3-C8 heterocyclo)-, -(C3-C8 heterocyclo)-C1-C 10alkylene-, -C1-C 10 alkylene-C(=O)-, C1-C 10 heteroalkylene-C(=O)-, -C3-C8carbocyclo-C(=O)-, -O-(C1-C8alkylene)-C(=O)-, -arylene-C(=O)-, -C1-C 10 alkylene-arylene-C(=O)-, -arylene-C1-C 10 alkylene-C(=O)-, -C1-C 10 alkylene-(C3-C8carbocyclo)-C(=O)-, -(C3-C8carbocyclo)-C1-C 10 alkylene-C(=O)-, -C3-C8heterocyclo-C(=O)-, -C1-C 10 alkylene-(C3-C8heterocyclo)-C(=O)-, -(C3-C8heterocyclo)-C1-C 10 alkylene-C(=O)-, -C1-C 10 alkylene-NH-, C1-C 10 heteroalkylene-NH-, -C3-C8carbocyclo-NH-, -O-(C1-C8alkylene)-NH-, -arylene-NH-, -C1-C 10 alkylene-arylene-NH-, -arylene-C1-C 10 alkylene-NH-, -C1-C 10 alkylene-(C3-C8carbocyclo)-NH-, -(C3-C8carbocyclo)-C1-C 10 alkylene-NH-, -C3-C8heterocyclo-NH-, -C1-C 10 alkylene-(C3-C8heterocyclo)-NH-, -(C3-C8heterocyclo)-C1-C 10 alkylene-NH-, -C1-C 10 alkylene-S-, C1-C 10 heteroalkylene-S-, -C3-C8carbocyclo-S-, -O-(C1-C8alkylene)-S-, -arylene-S-, -C1-C 10 alkylene-arylene-S-, -arylene-C1-C 10 alkylene-S-, -C1-C 10 alkylene-(C3-C8carbocyclo)-S-, -(C3-C8carbocyclo)-C1-C 10Alkylene-S-, -C3-C8 heterocyclo-S-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-S- or -(C3-C8 heterocyclo)-C1-C 10 is alkylene-S).

[0247] In yet another embodiment, the reactive group of the stretcher unit precursor contains a reactive nucleophile that is present on or introduced into the ligand unit and is capable of reacting with an electrophile. For example, the carbohydrate moiety on the targeting ligand can be mildly oxidized using a reagent such as sodium periodate, and the resulting electrophilic functional group (-CHO) of the oxidized carbohydrate can be condensed with a stretcher unit precursor containing a reactive nucleophile such as a hydrazide, oxime, primary or secondary amine, hydrazine, thiosemicarbazone, hydrazine carboxylate or arylhydrazide as described by Kaneko, T. et al. (1991) Bioconjugate Chem. 2:133-41. Representative stretcher units of this embodiment are illustrated within the brackets of Formulas Zdi, Zdii and Zdiii:

Chemical formula

[0248] (wherein the wavy line indicates a bond to the parallel connector unit (B) or the connector unit (A), or to the distributor (S * ) when A and B are absent, and R 17 is -C1-C 10 alkylene-, C1-C 10 heteroalkylene-, -C3-C8 carbocyclo-, -O-(C1-C8 alkylene)-, -arylene-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10Alkylene-, -C3-C8 heterocyclo-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-, -C1-C 10 Alkylene-C(=O)-, C1-C 10 Heteroalkylene-C(=O)-, -C3-C8 carbocyclo-C(=O)-, -O-(C1-C8 alkylene)-C(=O)-, -arylene-C(=O)-, -C1-C 10 Alkylene-arylene-C(=O)-, -arylene-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-C(=O)-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-C(=O)-, -C3-C8 heterocyclo-C(=O)-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-C(=O)-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-C(=O)-, -C1-C 10 Alkylene-NH-, C1-C 10 Heteroalkylene-NH-, -C3-C8 carbocyclo-NH-, -O-(C1-C8 alkylene)-NH-, -arylene-NH-, -C1-C 10 Alkylene-arylene-NH-, -arylene-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-NH-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-NH-, -C3-C8 heterocyclo-NH-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-NH-, -(C3-C8 heterocyclo)-C1-C 10 Alkylene-NH-, -C1-C 10 Alkylene-S-, C1-C 10 Heteroalkylene-S-, -C3-C8 carbocyclo-S-, -O-(C1-C8 alkylene)-S-, -arylene-S-, -C1-C 10 Alkylene-arylene-S-, -arylene-C1-C 10 Alkylene-S-, -C1-C 10 Alkylene-(C3-C8 carbocyclo)-S-, -(C3-C8 carbocyclo)-C1-C 10 Alkylene-S-, -C3-C8 heterocyclo-S-, -C1-C 10 Alkylene-(C3-C8 heterocyclo)-S- or -(C3-C8 heterocyclo)-C1-C 10 is alkylene-S).

[0249] In some embodiments of the present invention (preventinvention), the stretcher unit is about 1000 Daltons or less, about 500 Daltons or less, about 200 Daltons or less, about 30, 50 or 100 Daltons to about 1000 Daltons, about 30, 50 or 100 Daltons to about 500 Daltons, or about 30, 50 or 100 Daltons to about 200 Daltons in mass. Connector unit (A)

[0250] In some embodiments, it may be desirable to add an additional distance between the stretcher unit (Z) or its precursor (Z') and the cleavable linker in the connector unit (A), and it is included in the camptothecin conjugate or the camptothecin-linker compound. In some embodiments, the extra distance will assist in activation within the RL. Thus, the connector unit (A), when present, lengthens the framework of the linker unit. In that regard, the connector unit (A) is covalently bound to the stretcher unit (or its precursor) at one end and, at its other end, is covalently bound to an optional parallel connector unit or a distributor (S * ).

[0251] One of ordinary skill in the art understands that the linker unit can be any group that serves to effect the attachment of the releasable linker to the remainder of the linker unit (Q). The linker unit can include, for example, one or more (e.g., 1 to 10, preferably 1, 2, 3, or 4) natural or unnatural amino acids, amino alcohols, amino aldehydes, diamino residues. In some embodiments, the linker unit is a single natural or unnatural amino acid, amino alcohol, amino aldehyde, or diamino residue. An exemplary amino acid that can serve as the linker unit is β-alanine.

[0252] In some of those embodiments, the linker unit has the formula represented below:

Chemical formula

Chemical formula

[0253] (wherein the wavy line indicates the attachment of the linker unit within the camptothecin conjugate or camptothecin linker compound, and R 111 is hydrogen, p-hydroxybenzyl, methyl, isopropyl, isobutyl, sec-butyl, -CH2OH, -CH(OH)CH3, -CH2CH2SCH3, -CH2CONH2, -CH2COOH, -CH2CH2CONH2, -CH2CH2COOH, -(CH2)3NHC(=NH)NH2, -(CH2)3NH2, -(CH2)3NHCOCH3, -(CH2)3NHCHO, -(CH2)4NHC(=NH)NH2, -(CH2)4NH2, -(CH2)4NHCOCH3, -(CH2)4NHCHO, -(CH2)3NHCONH2, -(CH2)4NHCONH2, -CH2CH2CH(OH)CH2NH2, 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-,

Chemical formula

[0254] R 100 is independently selected from hydrogen or -C1-C3 alkyl, preferably hydrogen or CH3, and the subscript c is an integer independently selected from 1 to 10, preferably 1 to 3.) has.

[0255] Dispensing agent (S * ) or -B(S * )- Representative connector units having a carbonyl group for attachment are as follows:

Chemical formula

[0256] (wherein, in each case, R 13 is -C1-C6 alkylene-, -C3-C8 carbocyclo-, -arylene-, -C1-C 10 heteroalkylene-, -C3-C8 heterocyclo-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 heterocyclo)- and -(C3-C8 heterocyclo)-C1-C 10 alkylene- and is independently selected from the group consisting of, and the subscript c is an integer in the range of 1 to 4). In some embodiments, R 13 is -C1-C6 alkylene and c is 1.

[0257] Dispensing agent (S * ) or -B(S * )- Another representative connector unit having a carbonyl group for attachment is as follows:

Chemical formula

[0258] The representative linker units having an NH moiety bonded to the dispenser (S * ) or -B(S * )- are as follows: [Chemical formula]

[0259] (wherein, in each case, R 13 is -C1-C6 alkylene-, -C3-C8 carbocyclo-, -arylene-, -C1-C 10 heteroalkylene-, -C3-C8 heterocyclo-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 heterocyclo)- and -(C3-C8 heterocyclo)-C1-C 10 alkylene-, independently selected from the group consisting of, and the subscript c is from 1 to 14). In some embodiments, R 13 is -C1-C6 alkylene and the subscript c is 1.

[0260] The dispensing agent (S * ) or another representative linker unit having an NH moiety that binds to -B(S * )- is as follows: [Chemical formula]

[0261] (wherein R 13 is -C1-C6 alkylene-, -C3-C8 carbocyclo-, -arylene-, -C1-C 10 heteroalkylene-, -C3-C8 heterocyclo-, -C1-C 10 alkylene-arylene-, -arylene-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 carbocyclo)-, -(C3-C8 carbocyclo)-C1-C 10 alkylene-, -C1-C 10 alkylene-(C3-C8 heterocyclo)-, -(C3-C8 heterocyclo)-C1-C 10 alkylene-, -C(=O)C1-C6 alkylene- or -C1-C6 alkylene-C(=O)-C1-C6 alkylene).

[0262] Selected embodiments of the linker unit have the following structures [Chemical formula]

[0263] (wherein the wavy line adjacent to nitrogen represents a covalent bond, a stretcher unit (Z) (or its precursor Z'), and the wavy line adjacent to carbonyl represents a covalent bond to the dispensing agent (S * ) or -B(S * )-, and m is an integer in the range of 1 to 6, preferably 2 to 6, more preferably 2 to 4). including those having Releasable linker (RL)

[0264] The glucuronide unit is one type of releasable linker that realizes a mechanism for separating camptothecin from the ligand unit and other components of the linker unit through activation of a self-destruct cascade within the linker unit. In such embodiments, the self-destruct cascade is activated by manipulation of a glycosidase in the carbohydrate portion of the glucuronide unit. Several sugars are useful in the embodiments described herein. Specific carbohydrate portions include those of galactose, glucose, mannose, xylose, arabinose, mannose-6-phosphate, fucose, rhamnose, gulose, allose, 6-deoxy-glucose, lactose, maltose, cellobiose, gentiobiose, maltotriose, GlcNAc, GalNAc, and maltohexaose.

[0265] The glycoside unit typically includes a sugar moiety (Su) linked to a self-destructive spacer via an oxygen glycoside bond. Cleavage of the oxygen glycoside bond initiates a series of self-destruct reactions that result in the release of the free drug. In some embodiments, the series of self-destruction is activated from cleavage by β-glucuronidase of the glucuronide unit, which is an exemplary glycoside unit. The glucuronide unit includes an activation unit and a self-destructive spacer unit. The glucuronide unit includes a sugar moiety (Su) linked to the self-destructive spacer unit via an oxygen glycoside bond.

[0266] In some embodiments, the glucuronide unit is a self-destructive unit (SP) of the following formula via an oxygen glycoside bond (-O'-):

Chemical formula

[0267] (wherein the wavy line may optionally be a connector unit (A) or a parallel connector unit (B), a distributor (S *) or through a combination of a connector unit and a parallel connector unit, either directly or indirectly, any one of the drug units of formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7, or a spacer unit attached to the drug unit (camptothecin compound), and a covalent bond to the stretcher unit (Z) or its precursor (Z’)) contains a sugar moiety (Su) linked to

[0268] The oxygen glycosidic bond (-O’-) is usually a glycosidic bond cleavable by human lysosomal β-glucuronidase, such as a β-glucuronidase-cleavage site (i.e., Su is derived from glucuronide).

[0269] In some embodiments, the glucuronide unit can be represented by formula Ga or Gb:

Chemical formula

[0270] (wherein Su is a sugar moiety, -O’- represents an oxygen glycosidic bond, R 1S , R 2S and R 3S are independently hydrogen, halogen, -CN, -NO2 or other electron-withdrawing groups, or electron-donating groups, the wavy line represents a bond to the stretcher unit (Z) (or its precursor (Z’), connector unit or parallel connector unit, or through a connector unit and a parallel connector unit, either directly or indirectly), and # represents a bond to camptothecin or the spacer (either directly or indirectly through an intervening functional group or other moiety)).

[0271] In preferred embodiments, R 1S , R 2S and R 3S are independently selected from hydrogen, halogen, -CN or -NO2. In other preferred embodiments, R 1S , R 2S and R 3Sare each hydrogen. In other preferred embodiments, R 2S is an electron-withdrawing group, preferably NO2, and R 1S and R 3S are each hydrogen.

[0272] In some such embodiments, an activatable self-destructive group that enables a glycosidase cleavage to initiate a series of self-destructive reactions is represented by formula Gc:

Chemical formula

[0273] (wherein R 4S is CH2OH or -CO2H, the wavy line indicates a covalent bond to a stretcher unit (Z) (or its precursor Z') either directly or indirectly via a connector unit or a parallel connector unit, or a combination of a connector unit and a parallel connector unit, and the number symbol (#) indicates a covalent bond to a methylene carbamate unit).

[0274] In some embodiments where the activatable self-destructive moiety includes a glucuronide unit, the unit is represented by the following formula Gd:

Chemical formula

[0275] (wherein the wavy line indicates a covalent bond to a stretcher unit (Z) (or its precursor Z') either directly or indirectly via a connector unit or a parallel connector unit, or a combination of a connector unit and a parallel connector unit, and the number symbol (#) indicates a covalent bond to the benzyl-position carbon of a spacer or functional group attached to camptothecin).

[0276] Another type of releasable linker that realizes a mechanism for separating camptothecin from the ligand unit and other components of the linker unit by activation of the self-destructive cascade within the linker unit has a phenylene component that is J mIt contains a p-aminobenzyloxycarbonyl (PAB) moiety that is replaced by [[ID=]], and the subscript m indicating the number of substituents is an integer in the range of 0 to 4. Each J is independently -C1-C8 alkyl, -O-(C1-C8 alkyl), -halogen, -nitro or -cyano.

[0277] In some embodiments, RL is a self-destructive group capable of releasing -D without requiring individual hydrolysis steps or subsequent self-destruction events. In some embodiments, -RL- is linked to the carbonyl of -W via the amino nitrogen atom of the PAB group and is directly linked to -D via a carbonate group, and is a PAB moiety. In related embodiments, -RL- is linked to the carbonyl of -A-, -S * - or -B- and contains a PAB moiety that is directly linked to -D via a carbonate group. Without being bound by any particular theory or mechanism, a possible mechanism for releasing the drug from RL containing a PAB moiety directly bonded to -D via a carbonate group is shown in Toki et al. (2002) J Org. Chem. 67:1866-1872.

[0278] In some embodiments, the RL unit containing the PAB moiety has the following formula:

Chemical formula

[0279] (The subscript m is an integer in the range of 0 to 4, and each J is independently -C1-C8 alkyl, -O-(C1-C8 alkyl), -halogen, -nitro or -cyano) is represented by.

[0280] Other examples of self-destructive groups include, but are not limited to, 2-aminoimidazole-5-methanol derivatives (Hay et al. (1999) Bioorg. Med. Chem. Lett. 9:2237), and ortho or An aromatic compound electronically similar to the PAB moiety such as para-aminobenzyl acetal is included. Other RLs undergo cyclization upon amide bond hydrolysis, such as substituted and unsubstituted 4-aminobutyric acid amides (Rodrigues et al., Chemistry Biology, 1995, 2, 223), appropriately substituted bicyclo[2.2.1] and bicyclo[2.2.2] ring systems (Storm, et al., J. Amer. Chem. Soc., 1972, 94, 5815) and 2- aminophenylpropionic acid amide (Amsberry, et al., J. Org. Chem., 1990, 55, 5867).

[0281] In one embodiment, the RL is a branched bis(hydroxymethyl)styrene (BHMS) unit.

[0282] In some embodiments, the RL has the following formula:

Chemical formula

[0283] In some embodiments, RL comprises a heterocyclic "self-immolative moiety" of Formula I, II, or III that is attached to the drug and incorporates an amide group that initiates a reaction to ultimately cleave the self-immolative moiety from the drug upon hydrolysis by an intracellular protease, such that the drug is released in its active form from the conjugate. The linker portion further comprises a peptide sequence adjacent to the self-immolative moiety that is a substrate for an intracellular protease, such as cathepsin (e.g., cathepsin B), which cleaves the peptide at an amide bond shared with the self-immolative moiety. With respect to the embodiments disclosed herein, the PAB-containing RL is directly attached to the tertiary hydroxyl of the lactone ring present in each of CPT1 - CPT7, each of Compounds 14 - 14z of Table I, or each of Compounds 18a - 18r of Table J.

[0284] In some embodiments, the heterocyclic self-immolative group (RL) is selected from Formulas I, II, and III:

Chemical formula

[0285] (wherein the wavy line indicates the site of covalent attachment to the cell-specific ligand and the drug moiety, U is O, S, or NR 6 and Q is CR 4 or N, and V 1 , V 2 and V 3 are independently CR 4 or N, provided that in the case of Formulas II and III, at least one of Q, V 1 and V 2 is N, and T is pending from CPT1, CPT2, CPT3, CPT4, CPT5, CPT6, or CPT7 as a condition condition,

[0286] R 1 、R 2 、R 3 and R 4 are H, F, Cl, Br, I, OH, -N(R 5 )2, -N(R5 ) 3 + , C1-C8 alkyl halides, carboxylates, sulfates, sulfamates, sulfonates, -SO2R 5 , -S(=O)R 5 , -SR 5 , -SO2N(R 5 )2, -C(=O)R 5 , -CO2R 5 , -C(=O)N(R 5 )2, -CN, -N3, -NO2, C1-C8 alkoxy, C1-C8 halo-substituted alkyl, polyethyleneoxy, phosphonates, phosphates, C1-C8 alkyl, C1-C8 substituted alkyl, C2-C8 alkenyl, C2-C8 substituted alkenyl, C2-C8 alkynyl, C2-C8 substituted alkynyl, C6-C 20 aryl, C6-C 20 substituted aryl, C1-C 20 heterocyclic ring and C1-C 20 substituted heterocyclic ring, independently selected from the group consisting of, or when taken together, R 2 and R 3 form a carbonyl (=O), or a spiro carbocyclic ring consisting of 3 to 7 carbon atoms,

[0287] R 5 and R 6 are independently selected from H, C1-C8 alkyl, C1-C8 substituted alkyl, C2-C8 alkenyl, C2-C8 substituted alkenyl, C2-C8 alkynyl, C2-C8 substituted alkynyl, C6-C 20 aryl, C6-C 20 substituted aryl, C1-C 20 heterocyclic ring and C1-C 20 substituted heterocyclic ring,

[0288] C1-C8 substituted alkyl, C2-C8 substituted alkenyl, C2-C8 substituted alkynyl, C6-C 20 substituted aryl and C2-C 20 substituted heterocyclic ring are F, Cl, Br, I, OH, -N(R 5 )2, -N(R 5 )3 +, C1-C8 alkyl halides, carboxylates, sulfates, sulfamates, sulfonates, C1-C8 alkyl sulfonates, C1-C8 alkyl amines, 4-dialkylaminopyridinium, C1-C8 alkyl hydro xyls, C1-C8 alkyl thiols, -SO2R 5 , -S(=O)R 5 , -SR 5 , -SO2N(R 5 )2, -C(=O)R 5 , -CO2R 5 , -C(=O)N(R 5 )2, -CN, -N3, -NO2, C1-C8 alkoxys, C1-C8 trifluoroalkyls, C1-C8 alkyls, C3-C 12 carbocycles, C6-C 20 aryls, C2-C 20 heterocycles, and are independently substituted by one or more substituents selected from the group consisting of polyethyleneoxy, phosphonates, and phosphates).

[0289] The conjugate is stable extracellularly or in the absence of an enzyme capable of cleaving the amide bond of the self-destructive moiety. However, upon entry into the cell or upon exposure to a suitable enzyme, the amide bond is cleaved, initiating a spontaneous self-destructive reaction, resulting in cleavage of the bond that covalently links the self-destructive moiety to the drug, thereby releasing the drug in its non-derivatized form or pharmacologically active form.

[0290] The self-destructive moiety in the conjugate of the present invention incorporates one or more heteroatoms, thereby achieving improved solubility, improved cleavage rate, and / or reducing the tendency of the conjugate to aggregate. In some examples, such improvements of the heterocyclic self-destructive linker constructs of the present invention compared to non-heterocyclic PAB-type linkers result in surprising and unexpected biological properties such as improved efficacy, reduced toxicity, and / or improvement of one or more desired pharmacokinetic and / or pharmacodynamic properties.

[0291] In Formulas I - III, T is understood to be O since it is derived from a tertiary hydroxyl (-OH) in any one of the lactone ring moieties of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6, CPT7, Compounds 14a - 14z of Table I, and Compounds 18a - 18r of Table J.

[0292] Without being limited by theory or any particular mechanism, the presence of an electron-withdrawing group in the heterocyclic ring of the linker of Formula I, II, or III sometimes moderates the rate of cleavage.

[0293] In one embodiment, the self-destructive moiety is a group of Formula I where Q is N and U is O or S. Such groups have non-linear structural features that improve the solubility of the conjugate. In this context, R is sometimes H, methyl, nitro, or CF3. In one embodiment, Q is N and U is O, thereby forming an oxazole ring and R is H. In another embodiment, Q is N and U is S, thereby forming a thiazole ring optionally substituted by a Me or CF3 group at R.

[0294] In another exemplary embodiment, the self-destructive moiety is a group of Formula II where Q is N and 1 and 2 V 1 and 2 V 1 are each independently N or CH. In another embodiment, Q, 2 V 2 and 1 V 1 are each N. In another embodiment, Q and 2 V 1 are N while 2 V

[0295] In another embodiment, the self-destructive moiety is Q,1 , V 2 and V 3 is a group of formula III, where each of them is independently N or CH. In another embodiment, Q is N while V 1 , V 2 and V 3 are each N. In another embodiment, Q, V 1 and V 2 are each CH while V 3 is N. In another embodiment, Q, V 2 and V 3 are each CH while V 1 is N. In another embodiment, Q, V 1 and V 3 are each CH while V 2 is N. In another embodiment, Q and V 2 are both N while V 1 and V 3 are both CH. In another embodiment, Q and V 2 are both CH while V 1 and V 3 are both N. In another embodiment In another embodiment, Q and V 3 are both N while V 1 and V 2 are both CH.

[0296] Without being bound by theory, Scheme 1a illustrates a mechanism for releasing the free drug from the camptothecin drug unit that is linked to the releasable linker, which is a glucuronide unit, via the nitrogen atom of the amine substituent derived from the free drug. Scheme 1a:

Chemical formula

[0297] The camptothecin conjugates described herein also have a dispersant (S *) may be included. The dispensing agent portion is useful, for example, for masking the hydrophobicity of a particular camptothecin drug unit or linker unit component.

[0298] Representative dispensing agents include polyethylene glycol (PEG) units, cyclodextrin units, polyamides, hydrophilic peptides, polysaccharides, and dendrimers.

[0299] If a polyethylene glycol (PEG) unit, cyclodextrin unit, polyamide, hydrophilic peptide, polysaccharide, or dendrimer is included in Q, these groups may be present as "linear" components, or as side chain or branched components. In such embodiments where a branched form exists, the linker unit will typically include, for example, a lysine residue (or a parallel connector unit, B) that provides a simple functional conjugate of the PEG unit, for example, to the remainder of the linker unit. Polyethylene glycol unit (PEG)

[0300] Polydisperse PEG, monodisperse PEG, and individual PEGs can be used to make the compounds of the present invention. Polydisperse PEG is a heterogeneous mixture of sizes and molecular weights, while monodisperse PEG is typically purified from a heterogeneous mixture and thus results in a single chain length and molecular weight. Preferred PEG units are individual PEGs that are compounds synthesized in a stepwise manner rather than by a polymerization method. Individual PEGs result in single molecules with defined and specified chain lengths.

[0301] The PEG units provided herein include one or more polyethylene glycol chains. In some embodiments, the polyethylene glycol chains are linked together, for example, in a linear, branched, or star-shaped configuration. Typically, at least one of the PEG chains is derivatized at one end for covalent attachment to a suitable site on a component of the linker unit (e.g., B), or to a linker unit component (e.g., Z-A-S * -RL-, Z -A-S *In order to link two of (-RL-Y-) together by a covalent bond, it can be used as a linear (e.g., bifunctional) linking group inside. Exemplary bonds within the linker unit are by a non-cleavable linker group or a cleavable linker group upon conditions. Exemplary bonds are by an amide linker group, an ether linker group, an ester linker group, a hydrazone linker group, an oxime linker group, a disulfide linker group, a peptide linker group or a triazole linker group. In some embodiments, the bond within the linker unit is by a non-cleavable linker group. In some embodiments, the bond within the linker unit is not through an ester linker group, a hydrazone linker group, an oxime linker group or a disulfide linker group. In some embodiments, the bond within the linker unit is not by a hydrazone linker group.

[0302] A cleavable linker group upon conditions refers to a linker group that is substantially resistant to cleavage while circulating in plasma, but is susceptible to cleavage in an intracellular or intratumoral environment. A non-cleavable linker group is a linker group that is substantially resistant to cleavage in any biological environment. Chemical hydrolysis of hydrazone, reduction of disulfide, and enzymatic cleavage of peptide bond or glycoside linker group are examples of cleavable linker groups upon conditions.

[0303] In some embodiments, the PEG unit is directly attached to the parallel connector unit B. The other end (or terminus) of the PEG unit is free and unconstrained and may take the form of a methoxy, carboxylic acid, alcohol, or another suitable functional group. The methoxy, carboxylic acid, alcohol, or other suitable functional group serves as a cap on the terminal PEG subunit of the PEG unit. By unconstrained is meant that the PEG unit is not attached to camptothecin, an antibody, or another linking component at this unconstrained site. One of ordinary skill in the art understands that in addition to containing repeating polyethylene glycol subunits, the PEG unit may also contain non-PEG substances (e.g., to facilitate the coupling of multiple PEG chains to each other). Non-PEG substances refer to atoms in the PEG unit that are not part of the repeating -CH2CH2O- subunit. In some embodiments provided herein, the PEG unit comprises two monomeric PEG chains attached to each other via non-PEG elements. In other embodiments provided herein, the PEG unit comprises two linear PEG chains attached to a central core or parallel connector unit (i.e., the PEG unit itself is branched).

[0304] There are several PEG conjugation methods available to those of skill in the art [e.g., Goodson, etal. (1990) Bio / Technology 8:343 (PEGylation of interleukin-2 at its glycosylation site after site-directed mutagenesis); EP0401384 (coupling of PEG to G-CSF); Malik, etal., (1992) Exp. Hematol. 20:1028-1035 (tosyl chloride PEGylation of GM-CSF using; PCT Publication No. WO90 / 12874 (PEGylation of erythropoietin containing recombinantly introduced cysteine residues using cysteine-specific mPEG derivatives); U.S. Patent No. 5,757,078 (PEGylation of EPO peptide); U.S. Patent No. 5,672,662 (Poly(ethylene glycol) and related polymers monosubstituted with propionic or butanoic acids and functional derivatives thereof for biotechnical applications); U.S. Patent No. 6,077,939 (PEGylation of the N-terminal α-carbon of a peptide); Veronese et al., (1985) Appl. Biochem. Biotechnol 11:141-142 (PEGylation of an N-terminal α-carbon of a peptide with PEG-nitrophenylcarbonate ("PEG-NPC") or PEG-trichlorophenylcarbonate); and Veronese (2001) Biomaterials 22:405-417 (Review on PEGylation of peptides and proteins) are referred to for reference).

[0305] For example, PEG may be covalently bonded to an amino acid residue via a reactive group. The reaction The reactive groups are those to which an activated PEG molecule can bind (e.g., free amino or carboxyl groups). For example, the N-terminal amino acid residue and lysine (K) residues have free amino groups, and the C-terminal amino acid residue has a free carboxyl group. Thiol groups (e.g., found in cysteine residues) are also useful as reactive groups for binding PEG. Furthermore, enzyme-assisted methods for specifically introducing reactive groups (e.g., hydrazide, aldehyde, and aromatic-amino groups) at the C-terminus of a polypeptide have been described (see Schwarz, et al. (1990) Methods Enzymol. 184:160; Rose, et al. (1991) Bioconjugate Chem. 2:154; and Gaertner, et al. (1994) J. Biol. Chem. 269:7224). )

[0306] In some embodiments, the PEG molecule can be attached to the amino group using methoxylated PEG (“mPEG”) having various reactive moieties. Non-limiting examples of such reactive moieties include succinimidyl succinate (SS), succinimidyl carbonate (SC), mPEG-imidate, para-nitrophenyl carbonate (NPC), succinimidyl propionate (SPA), and cyanuric chloride. Non-limiting examples of such mPEG include mPEG-succinimidyl succinate (mPEG-SS), mPEG2-succinimidyl succinate (mPEG2-SS); mPEG-succinimidyl carbonate (mPEG-SC), mPEG2-succinimidyl carbonate (mPEG2-SC); mPEG-imidate, mPEG-para-nitrophenyl carbonate (mPEG-NPC), mPEG-imidate; mPEG2-para-nitrophenyl carbonate (mPEG2-NPC); mPEG-succinimidyl propionate (mPEG-SPA); mPEG2-succinimidyl propionate (mPEG2-SPA); mPEG-N-hydroxy-succinimide (mPEG-NHS); mPEG2-N-hydroxy-succinimide (mPEG2-NHS); mPEG-cyanuric chloride; mPEG2-cyanuric chloride; mPEG2-lysino-NPC and mPEG2-Lys-NHS.

[0307] Generally, at least one of the PEG chains constituting the PEG unit is functionalized, such that covalent bonding to other linker unit components is possible.

[0308] Functionalization includes, for example, by an amine, thiol, NHS ester, maleimide, alkyne, azide, carbonyl, or several other functional groups. In some embodiments, the PEG unit further comprises a non-PEG substance (i.e., a substance not containing -CH2CH2O-) that enables coupling to other linker unit components or facilitates coupling of two or more PEG chains.

[0309] The presence of PEG units (or other spacers) in the linker unit can have two potential effects on the pharmacokinetics of the resulting camptothecin conjugate. The desired effect is a decrease in clearance (and, as a result, an increase in exposure), which is induced by the exposed hydrophobic elements of the camptothecin conjugate or due to a decrease in non-specific interactions with camptothecin itself. The second effect, which is not desirable, is a decrease in volume and distribution rate, which sometimes occurs from an increase in the molecular weight of the camptothecin conjugate.

[0310] Increasing the number of PEG subunits increases the hydrodynamic radius of the conjugate and typically results in a decrease in the diffusion rate. Consequently, the decrease in the diffusion rate usually reduces the ability of the camptothecin conjugate to penetrate tumors (Schmidt and Wittrup, Mol Cancer Ther 2009;8:2861-2871). Due to these two competing pharmacokinetic effects, it is desirable to use PEG that is large enough to reduce the clearance of the camptothecin conjugate and thus increase plasma exposure, but not so large as to significantly reduce its diffusion rate and interfere with the ability of the camptothecin conjugate to reach the intended target cell population. For methods regarding selecting the optimal PEG size for a particular drug-linker, see the examples of US2016 / 0310612 (e.g., Examples 1, 18, and 21), which are incorporated herein by reference.

[0311] ​In one group of embodiments, the PEG unit includes one or more linear PEG chains, each having at least 2 subunits, at least 3 subunits, at least 4 subunits, at least 5 subunits, at least 6 subunits, at least 7 subunits, at least 8 subunits, at least 9 subunits, at least 10 subunits, at least 11 subunits, at least 12 subunits, at least 13 subunits, at least 14 subunits, at least 15 subunits, at least 16 subunits, at least 17 subunits, at least 18 subunits, at least 19 subunits, at least 20 subunits, at least 21 subunits, at least 22 subunits, at least 23 subunits or at least 24 subunits. In preferred embodiments, the PEG unit includes a total of at least 4 subunits, at least 6 subunits, at least 8 subunits, at least 10 subunits or at least 12 subunits. In some such embodiments, the PEG unit includes a total of about 72 or fewer subunits, preferably a total of about 36 or fewer subunits.

[0312] In another group of embodiments, the PEG units have a total of 4 to 72, 4 to 60, 4 to 48, 4 to 36, or 4 to 24 sub-units, 5 to 72, 5 to 60, 5 to 48, 5 to 36, or 5 to 24 sub-units, 6 to 72, 6 to 60, 6 to 48, 6 to 36, or 6 to 24 sub-units, 7 to 72, 7 to 60, 7 to 48, 7 to 36, or 7 to 24 sub-units, 8 to 72, 8 to 60, 8 to 48, 8 to 36, or 8 to 24 sub-units, 9 to 72, 9 to 60, 9 to 48, 9 to 36, or 9 to 24 sub-units, 10 to 72, 10 to 60, 10 to 48, 10 to 36, or 10 to 24 sub-units, 11 to 72, 11 to 60, 11 to 48, 11 to 36, or 11 to 24 sub-units, 12 to 72, 12 to 60, 12 to 48, 12 to 36, or 12 to 24 sub-units, 13 to 72, 13 to 60, 13 to 48, 13 to 36, or 13 to 24 sub-units, 14 to 72, 14 to 60, 14 to 48, 14 to 36, or 14 to 24 sub-units, 15 to 72, 15 to 60, 15 to 48, 15 to 36, or 15 to 24 sub-units, 16 to 72, 16 to 60, 16 to 48, 16 to 36, or 16 to 24 sub-units, 17 to 72, 17 to 60, 17 to 48, 17 to 36, or 17 to 24 sub-units, 18 to 72, 18 to 60, 18 to 48, 18 to 36, or 18 to 24 sub-units, 19 to 72, 19 to 60, 19 to 48, 19 to 36, or 19 to 24 sub-units, 20 to 72, 20 to 60, 20 to 48, 20 to 36, or 20 to 24 sub-units, 21 to 72, 21 to 60, 21 to 48, 21 to 36, or 21 to 24 sub-units, 22 to 72, 22 to 60, 22 to 48, 22 to 36, or 22 to 24 sub-units, 23 to 72, 23 to 60, 23 to 48, 23 to 36, or 23 to 24 sub-units, or 24 to 72, 24 to 60, 24 to 48, 24 to 36, or 24 sub-units.

[0313] Exemplary linear PEG units that may be used in any of the embodiments presented herein are as follows: [Chemical formula] (Wherein the wavy line indicates the binding site to the parallel connector unit (B), and n is independently selected from 4 to 72, 6 to 72, 8 to 72, 10 to 72, 12 to 72, 6 to 24, or 8 to 24, respectively). In some embodiments, the subscript b is about 4, about 8, about 12, or about 24.)

[0314] As described herein, the PEG unit is selected to improve the clearance of the resulting camptothecin conjugate without significantly affecting the ability of the conjugate to penetrate into the tumor. In embodiments, the PEG unit selected for use preferably has from 4 subunits to about 24 subunits, more preferably from about 4 subunits to about 12 subunits.

[0315] In a preferred embodiment of the present disclosure, the PEG unit is from about 300 daltons to about 5 kilodaltons; from about 300 daltons to about 4 kilodaltons; from about 300 daltons to about 3 kilodaltons; from about 300 daltons to about 2 kilodaltons; or from about 300 daltons to about 1 kilodalton. In some such embodiments, the PEG unit has at least 6 subunits or at least 8, 10, or 12 subunits. In some such embodiments, the PEG unit has at least 6 subunits or at least 8, 10, or 12 subunits, but has 72 or fewer subunits, preferably 36 or fewer subunits.

[0316] It will be understood that when referring to PEG subunits, and depending on the context, the number of subunits can represent an average number, for example, when referring to a population of camptothecin conjugates or camptothecin-linker compounds using polydisperse PEG. Parallel connector unit (B):

[0317] In some embodiments, the camptothecin conjugate and the camptothecin linker compound are a dispensing agent (-B(S in the linker unit *) would include parallel connector units that provide attachment points to the ) shown as. As a general embodiment, the PEG unit may be attached to parallel connector units such as lysine shown below, and the wavy lines and asterisks indicate covalent linking groups within the linker unit of the camptothecin conjugate or camptothecin linker compound:

Chem.

[0318] In some embodiments, the camptothecin conjugates provided herein have a spacer (Y) between the releasable linker (RL) and the camptothecin. The spacer unit can be a functional group that facilitates the attachment of the RL to the camptothecin or can provide additional structural components that further facilitate the release of the camptothecin unit from the remainder of the conjugate (e.g., a methylene carbamate unit).

[0319] In such embodiments where the release of the camptothecin unit is further facilitated as a free drug, exemplary spacer units have the following formula:

Chem.

[0320] wherein EWG represents an electron-withdrawing group, R 1 is -H or C1-C4 alkyl, and the subscript n is 1 or 2. In some embodiments, EWG is -CN, -NO2, -CX3, -X, C(=O)OR ’ , -C(=O)N(R ’ )2, -C(=O)R ’ , -C(=O)X, -S(=O)2R ’ , -S(=O)2OR ’ , -S(=O)2NHR ’ , -S(=O)2N(R ’ )2, -P(=O)(OR ’ )2, -P(=O)(CH3)NHR’ 、 -NO, -N(R ’ )3 + selected from the group consisting of, X is -F, -Br, -Cl or -I, and R ’ is independently selected from the group consisting of hydrogen and C1-C6 alkyl. The wavy line adjacent to the nitrogen atom in each of formulas (a), (a'), (a''), (b) and (b') is a covalent bond point to RL. The wavy line adjacent to the carbonyl carbon atom in formulas (b) and (b') is a hydroxyl group of any one of the camptothecin compounds of formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or any one of compounds 14a-14z in Table I, or any one of compounds 18a-18r in Table J, or a covalent bond point to the heteroatom of a primary or secondary amine,

[0321] Formulas (a), (a') and (a'') represent exemplary methylene carbamate units, and T * is a hydroxyl group of any one of the camptothecin compounds of formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or any one of compounds 14a-14z in Table I, or any one of compounds 18a-18r in Table J, or a heteroatom derived from a primary or secondary amine functional group. The wavy line adjacent to T * is a covalent bond point to the remainder of the camptothecin drug unit corresponding structurally to the camptothecin compound.

[0322] In yet another embodiment, the spacer unit that is a methylene carbamate unit has the following formula:

Chemical formula

[0323] wherein each R is independently -H or C1-C4 alkyl. Formulas (a1) and (a1') represent methylene carbamate units, and O *is a camptothecin compound of formula CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or any one of compounds 14a - 14z in Table I, or any one of compounds 18a - 18r in Table J, derived from a hydroxyl substituent on the lactone ring, or from another hydroxyl substituent of a camptothecin compound of CPT5 or CPT7, or R F and R F’ wherein at least one of them is C1 - C8 hydroxyalkyl N,N-(C1 - C4 hydroxyalkyl)(C1 - C4 alkyl)-amino-C1 - C8 alkyl- or N-C1 - C4 hydroxyalkyl-C1 - C8 aminoalkyl-, C1 - C8 alkyl C(O)-, the oxygen atom derived from the hydroxyl substituent of R F or R F’ in CPT6,

[0324] The wavy lines in formula (a1), formula (a1’) and formula (b1) respectively retain their previous meanings from formula (a), (a’) and (b). In formula (a1’), -CH2CH2N + (R)2 part represents an exemplary basic unit in protonated form.

[0325] Without being bound by theory, Scheme 1b illustrates the release mechanism of the free drug from camptothecin attached to the methylene carbamate unit in a camptothecin conjugate having a self-destructive moiety. In that scheme, T * is a heteroatom derived from a hydroxyl, or a primary or secondary amine of the camptothecin compound incorporated in the methylene carbamate unit. Scheme 1b:

Chemical Structure

[0326] In one group of embodiments of the present invention, the subscript p represents the number of drug linker moieties on the ligand unit of an individual camptothecin conjugate, and is preferably an integer in the range of 1 to 16, 1 to 12, 1 to 10, or 1 to 8. An individual camptothecin conjugate can also be referred to as a camptothecin conjugate compound. In such a group of embodiments, there are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 drug linker moieties conjugated to the ligand unit of the individual camptothecin conjugate. In another group of embodiments of the present invention, a camptothecin conjugate refers to a population of individual camptothecin conjugate compounds that are substantially identical except for the number of camptothecin drug linker moieties attached to each ligand unit (i.e., a camptothecin conjugate composition), and as a result, the subscript p represents the average number of camptothecin drug linker moieties attached to the ligand units of the camptothecin conjugate composition. In such a group of embodiments, the subscript p is a number in the range of 1 to about 16, 1 to about 12, 1 to about 10, or 1 to about 8, 2 to about 16, 2 to about 12, 2 to about 10, or 2 to about 8. In some embodiments, the value of the subscript p refers to the average drug loading in the composition and the drug loading of the major ADC.

[0327] In some embodiments, the conjugate is via an interchain disulfide and is 1 to about 8 camptothecin linker compound molecules conjugated to a targeting agent that serves as a ligand unit. In some embodiments, the conjugate is via an introduced cysteine residue and an interchain disulfide and is 1 to 10 or 1 to 12 or 1 to 14 or 1 to 16 camptothecin linker compound moieties conjugated to the ligand unit. In some embodiments, the conjugate is via an introduced cysteine residue and will be 2 or 4 camptothecin linker compound molecules conjugated to the ligand unit. [Table 11-1]

Table 11-2

Chemical formula

Chemical formula

Table 12-1

Table 12-2

Table 12-3

[0328] The present invention provides a camptothecin conjugate mixture as described herein, and a pharmaceutical composition comprising any of the camptothecin conjugates. The mixture and the pharmaceutical composition comprise a plurality of conjugates. In some embodiments, the conjugates in the mixture or composition are each identical or substantially identical, but the distribution of drug-linkers and the drug loading on the ligands in the mixture or composition can vary. For example, in some embodiments, the conjugation techniques used to conjugate a drug-linker to an antibody as a targeting agent result in a composition or mixture that is heterogeneous with respect to the distribution of camptothecin linker compounds on the antibody (ligand unit) within the mixture and / or composition. In some of such embodiments, the loading of camptothecin linker compounds in each of the antibody molecules in such a mixture or composition of molecules is an integer in the range of 1 to 16.

[0329] In those embodiments, when referring to the composition as a whole, the drug-linker loading amount is a number in the range of 1 to about 16. Within the composition or mixture, there may be a small percentage of unconjugated antibody. The average number of drug-linkers per ligand unit in the mixture or composition (i.e., the average drug-loading amount) is an important attribute as it relates to the maximum amount of drug that can be delivered to the target cell. Typically, the average drug-loading amount is 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.

[0330] In some embodiments, the mixture and pharmaceutical composition comprise a plurality (i.e., a population) of conjugates, and these conjugates are the same or substantially the same with respect to the distribution of drug-linkers on the ligand molecules within the mixture and / or composition, and with respect to the loading amount of drug-linkers on the ligand molecules within the mixture and / or composition, and are substantially homogeneous. In some such embodiments, the loading amount of drug-linkers on the antibody ligand unit is 2 or 4. There may also be a small percentage of unconjugated antibody within the composition or mixture. In such embodiments, the average drug-loading amount is about 2 or about 4. Typically, such compositions and mixtures result from the use of site-specific conjugation techniques, and the conjugates are due to introduced cysteine residues.

[0331] In preparations from the conjugation reaction, the average number of camptothecin or camptothecin-linker compounds per ligand unit is typically characterized by conventional means such as mass spectrometry, ELISA assays, HPLC (e.g., HIC). In those examples, the quantitative distribution of the camptothecin conjugate with respect to the subscript p is typically determined. In other examples, the separation, purification, and characterization of homogeneous camptothecin conjugates are typically achieved by conventional means such as reverse-phase HPLC or electrophoresis.

[0332] In some embodiments, the composition is a pharmaceutical composition comprising a camptothecin conjugate described herein and a pharmaceutically acceptable carrier. In some of those embodiments, the pharmaceutical composition is in liquid form. In others of those embodiments, the pharmaceutical composition is a lyophilized powder.

[0333] Compositions comprising the pharmaceutical composition can be provided in purified form. As used herein, "purified" means that when isolated, the isolate contains at least 95% conjugate, in other embodiments at least 98% conjugate, by weight of the isolate. Method of Use Treatment of Cancer

[0334] Camptothecin conjugates are useful for inhibiting the growth of tumor cells or cancer cells, for causing apoptosis in tumor or cancer cells, or for treating cancer in a patient. Thus, camptothecin conjugates are used in a variety of situations for the treatment of cancer. Camptothecin conjugates are intended to deliver a drug to tumor cells or cancer cells. Without being bound by theory, in one embodiment, the ligand unit of the camptothecin conjugate binds to or associates with a cancer cell or tumor cell - associated antigen, and the camptothecin conjugate is taken up (internalized) into the interior of the tumor cell or cancer cell by receptor - mediated endocytosis or other internalization mechanisms. In some embodiments, the antigen is an extracellular matrix protein that binds to or is associated with the tumor cell or cancer cell. Once inside the cell, the drug is released inside the cell via activation of the activation unit. In an alternative embodiment, the free drug is released from the camptothecin conjugate outside the tumor cell or cancer cell, and then this free drug penetrates the cell.

[0335] In one embodiment, the ligand unit binds to a tumor cell or cancer cell.

[0336] In another embodiment, the ligand unit is on the surface of a tumor cell or cancer cell and binds to the antigen of the tumor cell

[0337] In another embodiment, the ligand unit binds to the antigen of a tumor cell or cancer cell, which is an extracellular matrix protein associated with the tumor cell or cancer cell.

[0338] The specificity of the ligand unit for a particular tumor cell or cancer cell is an important consideration for determining the tumor or cancer that is most effectively treated. For example, a camptothecin conjugate that targets a cancer cell antigen present in hematopoietic tissue cancers is useful for treating blood malignancies (e.g., anti-CD30, anti-CD70, anti-CD19, anti-CD33 binding ligand units (e.g., antibodies) are useful for treating blood malignancies). A camptothecin conjugate that targets a cancer cell antigen present in solid tumors is useful for treating such solid tumors in some embodiments.

[0339] Cancers intended to be treated with the camptothecin conjugate include, but are not limited to, for example, hematopoietic tissue cancers such as lymphoma (Hodgkin's lymphoma and non-Hodgkin's lymphoma) and leukemia, as well as solid tumors. Examples of hematopoietic tissue cancers include follicular lymphoma, undifferentiated large cell lymphoma, mantle cell lymphoma, acute myeloblastic leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, diffuse large B cell lymphoma, and multiple myeloma. Examples of solid tumors include 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, gastric cancer, oral cancer, nasal cancer, laryngeal cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchiogenic carcinoma, renal cell carcinoma, hepatoma, cholangiocarcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms tumor, cervical cancer, uterine cancer, testicular cancer, small cell lung cancer, bladder cancer, lung cancer, epithelial carcinoma, glioma, glioblastoma multiforme, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, neuroblastoma, and retinoblastoma.

[0340] In a preferred embodiment, the cancer to be treated is any one of the lymphomas and leukemias listed above. Combined modality cancer therapy

[0341] Cancer, including but not limited to tumors, metastases, or other diseases or disorders characterized by uncontrolled cell growth, is intended to be treated or inhibited by administering an effective amount of a camptothecin conjugate.

[0342] In one group of embodiments, there is provided a method of treating cancer comprising the step of administering to a patient in need thereof an effective amount of a camptothecin conjugate and a chemotherapeutic agent. In one embodiment, the chemotherapeutic agent is one for which the treatment of cancer has not been found to be refractory. In another embodiment, the chemotherapeutic agent is one for which the treatment of cancer has been found to be refractory.

[0343] In another group of embodiments, the camptothecin conjugate is administered to a patient who has also received surgery as a treatment for cancer. In such embodiments, a chemotherapeutic agent, i.e., one or a combination of chemotherapeutic agents, is typically administered over a series of sessions, and such chemotherapeutic agents of standard treatment are administered.

[0344] In any group of embodiments, the patient also receives additional treatments such as radiation therapy. In a specific embodiment, the camptothecin conjugate is administered simultaneously with the chemotherapeutic agent or radiation therapy. In another specific embodiment, the chemotherapeutic agent or radiation therapy is administered before or after administration of the camptothecin conjugate.

[0345] Furthermore, there is provided a method of treating cancer using a camptothecin conjugate as an alternative to chemotherapy or radiation therapy where the toxicity of the chemotherapy or radiation therapy is found, or can be found, to be too high, for example, resulting in unacceptable or intolerable side effects for the subject being treated. The patient to be treated is treated, if necessary, by another cancer treatment such as surgery, radiation therapy or chemotherapy, depending on what treatment is found to be acceptable or tolerable. Treatment of autoimmune diseases

[0346] The camptothecin conjugate is intended to be useful for killing cells that give rise to autoimmune diseases, or for inhibiting their unwanted replication, or for treating autoimmune diseases.

[0347] Accordingly, the camptothecin conjugate is used in a variety of situations for the treatment of autoimmune diseases in patients. The camptothecin conjugate is typically used to deliver the camptothecin drug to target cells. Without being bound by theory, in one embodiment, the camptothecin conjugate associates with an antigen on the surface of inflammatory or inappropriately stimulated immune cells, and the camptothecin conjugate is then taken up into the interior of the target cell by receptor-mediated endocytosis. Once inside the cell, the linker unit is cleaved, releasing the camptothecin drug unit as a free drug. The camptothecin free drug can then move into the cytosol and induce cytotoxic or cytostatic activity. In an alternative embodiment, the camptothecin drug unit is cleaved from the camptothecin conjugate outside the target cell, and the camptothecin free drug resulting from such release subsequently penetrates the cell.

[0348] In one embodiment, the ligand unit binds to an autoimmune antigen. In such an embodiment, the antigen is present on the surface of cells involved in the autoimmune condition.

[0349] In one embodiment, the ligand unit binds to activated lymphocytes associated with an autoimmune disease state.

[0350] In a further embodiment, the camptothecin conjugate kills or inhibits the growth of cells that give rise to autoantibodies associated with a particular autoimmune disease.

[0351] Particular types of autoimmune diseases intended to be treated by the camptothecin conjugate include, but are not limited to, Th2 lymphocyte-related disorders (e.g., atopic dermatitis, atopic asthma, rhinitis, allergic rhinitis, Wiskott-Aldrich syndrome, systemic sclerosis, and graft-versus-host disease); Th1 lymphocyte-related disorders (e.g., rheumatoid arthritis, multiple sclerosis, psoriasis, Sjogren's syndrome, Hashimoto's thyroiditis, Graves' 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 for autoimmune diseases

[0352] Also disclosed is a method for treating an autoimmune disease comprising the step of administering to a patient in need thereof an effective amount of a camptothecin conjugate and another therapeutic agent known for the treatment of autoimmune diseases. Compositions and methods of administration

[0353] The present invention provides a pharmaceutical composition comprising the camptothecin conjugate described herein and at least one pharmaceutically acceptable carrier. The pharmaceutical composition is in any form that enables administration of the compound to a patient for treating a disorder associated with the expression of an antigen to which the ligand unit binds. For example, the conjugate is in liquid or solid form. The preferred route of administration is parenteral. Parenteral administration includes subcutaneous injection, intravenous, intramuscular, intra-sternal injection or infusion techniques. In one embodiment, the pharmaceutical composition is administered parenterally. In one embodiment, the conjugate is administered intravenously. Administration is by any convenient route, for example by infusion or bolus injection.

[0354] The pharmaceutical composition is formulated such that the camptothecin conjugate is bioavailable upon administration of the composition to a patient. The composition sometimes takes the form of one or more dosage units.

[0355] The substances used in preparing the pharmaceutical composition are preferably non-toxic in the amounts used. It will be apparent to those skilled in the art that the optimal dosage of the active ingredient in the pharmaceutical composition depends on various factors. Relevant factors include, but are not limited to, the type of animal (e.g., human), the specific form of the compound, the mode of administration, and the composition used.

[0356] In some embodiments, the composition is in liquid form. In some of those embodiments, the liquid is useful for delivery by injection. In some embodiments, the composition for administration by injection contains, in addition to the camptothecin conjugate, one or more excipients selected from the group consisting of surfactants, preservatives, wetting agents, dispersing agents, suspending agents, buffering agents, stabilizers, and isotonic agents.

[0357] In some embodiments, the liquid composition, whether they are in solution, suspension, or other similar forms, includes: water for injection, aqueous sodium chloride solution, preferably physiological saline, Ringer's solution, sterile diluents, solvents, or suspending media such as isotonic sodium chloride, synthetic monoglyceride or diglyceride that can act as a suspending medium, polyethylene glycol One or more of non-volatile oils such as leu, glycerin, cyclodextrin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as amino acids, acetates, citrates or phosphates; detergents such as nonionic surfactants, polyols; and agents for adjusting tonicity such as sodium chloride or dextrose. The parenteral composition is sometimes enclosed in an ampoule, disposable syringe or multi-dose vial made of glass, plastic or other materials. Physiological saline is an exemplary adjuvant. The injectable composition is preferably sterile.

[0358] The amount of conjugate effective in the treatment of a particular disorder or condition depends, in part, on the nature of the disorder or condition as determined by standard clinical techniques in some embodiments. Additionally, in vitro or in vivo assays are used as needed to assist in determining the optimal dosage range. The exact dosage used in the composition also depends on the route of administration and the severity of the disease or disorder and should be determined according to the physician's judgment and the circumstances of each patient.

[0359] To obtain a suitable dosage, the composition contains an effective amount of a camptothecin conjugate. Typically, this amount is at least about 0.01% of the compound, based on the weight of the composition.

[0360] In the case of intravenous administration, the pharmaceutical composition usually contains about 0.01 to about 100 mg of camptothecin conjugate per kg of the animal's body weight. In one embodiment, the composition can contain about 1 to about 100 mg of camptothecin conjugate per kg of the animal's body weight. In another aspect, the dosage is in the range of about 0.1 to about 25 mg / kg of the compound per body weight. The dosage can be further reduced depending on the drug used. For example, it can be 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 per body weight of the subject.

[0361] Generally, the dosage of the conjugate administered to a patient is usually about 0.01 mg / kg to about 100 mg / kg per body weight of the subject, or 1.0 μg / kg to 5.0 mg / kg per body weight of the subject. In some embodiments, the dosage administered to the patient is between about 0.01 mg / kg and about 15 mg / kg per body weight of the subject. In some embodiments, the dosage administered to the patient is between about 0.1 mg / kg and about 15 mg / kg per body weight of the subject. In some embodiments, the dosage administered to the patient is between about 0.1 mg / kg and about 20 mg / kg per body weight of the subject. In some embodiments, the dosage administered is between about 0.1 mg / kg and about 5 mg / kg or about 0.1 mg / kg and about 10 mg / kg per body weight of the subject. In some embodiments, the dosage administered is between about 1 mg / kg and about 15 mg / kg per body weight of the subject. In some embodiments, the dosage administered is between about 1 mg / kg and about 10 mg / kg per body weight of the subject. In some embodiments, the dosage administered is between about 0.1 to 4 mg / kg, more preferably 0.1 to 3.2 mg / kg, or even more preferably 0.1 to 2.7 mg / kg per body weight of the subject over the treatment cycle.

[0362] The term "carrier" refers to a diluent, adjuvant or excipient with which a compound is co-administered. In some embodiments, such pharmaceutical carriers are liquids such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil. Other carriers include saline, acacia gum, gelatin, starch paste, talc, keratin, colloidal silica, urea. In addition, auxiliary agents, stabilizers, thickeners, lubricants and coloring agents are sometimes used. In one embodiment, when administered to a patient, the camptothecin conjugate or its composition, and the pharmaceutically acceptable carrier are sterile.

[0363] Water is an exemplary carrier when the compound is administered intravenously. Aqueous saline solutions and aqueous dextrose and glycerol solutions are often used as liquid carriers, particularly for injectable solutions. Suitable pharmaceutical carriers also include excipients such as starch, glucose, lactose, sucrose, gelatin, malt, corn, wheat flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, skim milk powder, glycerol, propylene, glycol, water, ethanol. The composition may also contain, if desired, small amounts of wetting or emulsifying agents, or pH buffering agents.

[0364] In an embodiment, the conjugate is formulated as a pharmaceutical composition suitable for intravenous administration to animals, particularly humans, according to standard procedures. Typically, the carrier or vehicle for intravenous administration is a sterile isotonic aqueous buffer. If necessary, the composition includes a solubilizing agent. The composition for intravenous administration optionally includes a local anesthetic, such as lignocaine, to reduce pain at the injection site. Generally, the components are supplied individually in unit dosage forms, for example, as dry lyophilized powders or water-free concentrates, in airtight sealed containers, such as ampoules or sachets, indicating the amount of the active agent, or are mixed together. When the conjugate is administered by infusion, the conjugate is usually dispensed into an infusion bottle containing, for example, sterile pharmaceutical grade water or saline. When the conjugate is administered by injection, sterile ampoules of water are sometimes provided.

[0365] The pharmaceutical composition is generally formulated as a sterile, substantially isotonic one and in full compliance with all of the manufacturing and quality control standards (GMP) rules of the United States Food and Drug Administration for pharmaceuticals and drug products. Method for preparing a camptothecin conjugate

[0366] The camptothecin conjugates described herein are prepared either in a serial configuration of an antibody, a linker, and a drug unit or by assembling some parts and then in a convergent manner by a completed assembly step. A methylene carbamate linker (spacer), useful in some embodiments of the conjugates described herein, can be obtained using Curtius rearrangement or chloramine synthesis.

[0367] Scheme 2: Preparation of exemplary camptothecin drug-linker compounds of Z’-A-RL-Y-D, Z’-A-S * -RL-Y-D or Z’-A-B(S * )-RL-Y-D [Chem.]

[0368] Scheme 2 illustrates a synthetic strategy involving the Curtius rearrangement of an acyl azide derivative of the free drug, where CPT is a hydroxyl functional group, the oxygen atom of which (represented by O * ), is incorporated into the methylene carbamate unit formed as a result of the rearrangement, and is a camptothecin drug unit corresponding to a structurally camptothecin compound having a hydroxyl functional group, Z’ is a spacer unit precursor, RL is a releasable linker, X is -A-, -A-S * - or -A-B(S * )-, A is a connector unit, S * is a dispenser, and B is a parallel connector unit. Since there are numerous complementary methods for forming acyl azides, such as alkylation of halo esters, alkylation of halo acids, or metal carbene insertion with ethyl or methyl diazoacetate, this strategy may be applied to camptothecin drugs containing multiple alcohols or other heteroatoms as a means of obtaining regioselectivity. See Doyle, M. etal. Modern Catalytic Methods for Organic Synthesis with Diazo Compounds; Wiley: New York, 1998. Next, the acyl azide is heated with a linker unit intermediate of the formula Z’-X-RL-OH containing at least a stoichiometric amount of alcohol .

[0369] Scheme 3: Alternative preparation by N-chloromethylamine synthesis of exemplary camptothecin drug-linker compounds of the formula Z’-A-RL-Y-D, Z’-A-S * -RL-Y-D or Z’-A-B(S * )-RL-Y-D, where the spacer unit Y is a methylene carbamate unit of the formula (a) or formula (a’) [Chem.]

[0370] (wherein, R 1 is hydrogen or C1-C4 alkyl, R is -H or -CH2CH2SO2Me, and the other variable groups have their meanings from Scheme 2)

[0371] The N-chloromethylamine synthesis is an alternative to the Curtius rearrangement in that it allows the introduction of unmodified alcohols or other heteroatom-containing camptothecin compounds which cannot be compatible with the conditions necessary to form the acyl azide of Scheme 2, and proceeds by condensation with a reactive N-chloromethylamine. The method is also more suitable, for example, for introducing a certain type of methylene carbamate unit as shown by Scheme 4.

[0372] Scheme 4 shows that the spacer unit (Y) is a methylene carbamate unit of formula (a”), the formula Z’-A-RL-Y-D, Z’-A-S * -RL-Y-D or Z’-A-B(S *)-RL-Y-D demonstrates the synthesis of exemplary camptothecin-linker compounds. The reaction of p-nitro-phenyl carbonate with a cyclic aminoalcohol yields a carbamate, which is then converted to a chlorocycloalkylamine for alkylation with a nucleophile derived from a thiol, hydroxyl, amine, or amide functional group of the free camptothecin drug. Alternatively, this carbamate can be treated with an acid in the presence of the drug moiety to assemble the shown drug-linker intermediate. The alkylation product is deprotected, and then the resulting free amine is condensed with N-hydroxysuccinimide ester of 3-maleimidopropionic acid, thereby introducing a stretcher unit precursor covalently linked to the linker unit, and thus a camptothecin-linker compound is obtained. Next, the resulting camptothecin-linker compound is condensed with a thiol-containing targeting agent to obtain a camptothecin conjugate having a self-destructive moiety and a spacer unit containing a methylene carbamate unit of formula a”.

[0373] Scheme 4: Preparation of an exemplary camptothecin drug-linker compound of formula Z’-A-RL-Y-D, where the spacer unit Y is a methylene carbamate unit of formula (a”)

Chemical formula

Chemical formula

[0374] T *In the case of camptothecin-linker compounds and camptothecin conjugates having a methylene carbamate unit in which the nitrogen atom is derived from a primary or secondary amine substituent of a camptothecin compound, direct alkylation with chlormethylamine according to the general procedure presented by Scheme 3 or Scheme 4 may not be suitable due to the extra nitrogen heteroatom from the amine functional group of the free drug, i.e., unwanted overalkylation. In those examples, a method embodied by Scheme 5 may be used.

[0375] Scheme 5:

Chemical formula

[0376] In Scheme 5, as the R substituent in the case of the methylene carbamate unit of formula (a1’), an intermediate carbamate having a basic unit (i.e., a dimethylaminoethyl moiety) is prepared. The nitrogen of that carbamate is condensed with formaldehyde, and the resulting intermediate is quenched with the amine functional group of an aliphatic amine-containing camptothecin drug. N * represents the nitrogen atom from that functional group. By that condensation, a methylene carbamate of formula (a1’) covalently bonded to a camptothecin drug unit in which R 1 is hydrogen and R is dimethylaminoethyl is formed. Next, the phenyl nitro group is reduced to an amine to obtain a handle for the successive introduction of the linker unit (A) and the precursor of the spacer unit (Z’). Numbered embodiments

[0377] The following numbered embodiments describe various non-limiting aspects of the present invention.

[0378] 1. A camptothecin conjugate having the formula L-(Q-D) p or a salt thereof, wherein L is a ligand unit, the subscript p is an integer in the range of 1 to 16, and Q is -Z-A-, -Z-A-RL, -Z-A-RL-Y-, -Z-A-S* -RL-, -Z-A-S * -RL-Y-, -Z-A-S * -W-, -Z-A-S * -W-RL-, -Z-A-B(S * )-RL-, -Z-A-B(S * )-W-, -Z-A-B(S * )-W-RL- and -Z-A-B(S * )-RL-Y- and is a linker unit having a formula selected from the group consisting of, Z is a stretcher unit, A is a linking or connector unit, B is a parallel connector unit, S * is a dispenser, RL is a releasable linker, W is an amino acid unit, Y is a spacer unit, D is the following: [Chemical formula] [Chemical formula]

[0379] (wherein R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each, -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)-amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkylC(O)-, C3-C 10 cycloalkyl, (C3-C10 Cycloalkyl)-C1-C4 alkyl-, C3-C 10 Heterocycloalkyl, (C3-C 10 Heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl-C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl- Is a member independently selected from the group consisting of, or R F And R F’ Are, together with the nitrogen atom to which each is attached, a 5-membered, 6-membered or 7-membered ring having 0 to 3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, and R B 、R C 、R F And R F’ The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of are substituted by 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2) Is a drug unit selected from the group consisting of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7 as shown in, or

[0380] D is a drug unit selected from the group consisting of 13a-13c of Table H, 14a-14z of Table I, and 18a-18r of Table J, and

[0381] The covalent bond point of D is such that Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- or -Z-A-B(S *)-RL-Y- is the case, it is for any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7, or for any one of the heteroatoms of any one of the hydroxyl or aliphatic primary or secondary amino substituents in Tables H 13a - 13c, Tables I 14a - 14z, and Tables J 18a - 18r, or

[0382] The covalent bond point of D, where Q is, -Z-A-, -Z-A-S * -W- or -Z-A-B(S * )-W- is the case, or Q is, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- or -Z-A-B(S * )-W-RL- (RL is a releasable unit other than the glucuronide unit) is the case, it is for any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or for the oxygen atom of the hydroxyl substituent on any one of the lactone rings in Tables H 13a - 13c, Tables I 14a - 14z, and Tables J 18a - 18r, and

[0383] However, when the covalent bond point is for the nitrogen atom of the primary or secondary aliphatic amino substituent of CPT6, R F and R F’ at least one of them is -H, and when D is the compound CPT1 having a covalent bond through the nitrogen atom of its amino substituent, -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- and -Z-A-B(S * )-RL-Y- the -Z-A- is, as a succinamide moiety, other than the succinimide - caproyl - β - alanyl moiety having a hydrolyzed form of the succinimide ring as required, Camptothecin conjugate or a salt thereof.

[0384] 2. Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- and -Z-A-B(S * )-RL-Y-; A is a connector unit; RL is a glucuronide unit; the camptothecin conjugate of Embodiment 1.

[0385] 3. The covalent bond point of D is via the oxygen atom of the hydroxyl substituent on the lactone ring of any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7; the camptothecin conjugate of Embodiment 1 or 2.

[0386] 4. The covalent bond point of D is via the oxygen atom of the hydroxyl substituent on the lactone ring of any one of 13a - 13c of Table H, 14a - 14z of Table I, or 18a - 18r of Table J; the camptothecin conjugate of Embodiment 1 or 2.

[0387] 5. The covalent bond point of D is via the oxygen atom of the hydroxyl substituent of R F and R F’ when at least one of them is C1 - C8 hydroxyalkyl N,N-(C1 - C4 hydroxyalkyl)(C1 - C4 alkyl)-amino-C1 - C8 alkyl-, N-C1 - C4 hydroxyalkyl-C1 - C8 aminoalkyl-, C1 - C8 alkyl C(O)-; the camptothecin conjugate of Embodiment 1 or 2 via the oxygen atom of the hydroxyl substituent of R F or R F’ of CPT6.

[0388] 6. The covalent bond point of D is via the oxygen atom of the hydroxyl substituent of R F and R F’When at least one of them is C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl- or C1-C8 aminoalkyl C(O)-, R of CPT6 F or R F’ is via the nitrogen atom of the amine substituent of the camptothecin conjugate of Embodiment 1 or 2.

[0389] 7. The covalent bond point of D is via the nitrogen atom of the amino substituent of CPT1, provided that -Z-A- is other than succinimide-caproyl-β-alanyl having a hydrolyzed form of a succinimide ring as a succinamide moiety as required, the camptothecin conjugate of Embodiment 1 or 2.

[0390] 8. The covalent bond point of D is for the nitrogen atom of the amino substituent of CPT4, the camptothecin conjugate of Embodiment 1 or 2.

[0391] 9. The covalent bond point is via the nitrogen atom of the substituent of CPT6, provided that F and R F’ at least one of them is -H, the camptothecin conjugate of Embodiment 1 or 2.

[0392] 10. Q is a linker unit having a formula selected from the group consisting of -Z-A-RL- and -Z-A-RL-Y-, the camptothecin conjugate of any one of Embodiments 1-9.

[0393] 11. Q is a linker unit having a formula selected from the group consisting of -Z-A-S * -RL- and -Z-A-S * -RL-Y-, the camptothecin conjugate of any one of Embodiments 1-9.

[0394] 12. Q is -Z-A-B(S *)-RL- and -Z-A-B(S * )-RL-Y, being a linker unit having a formula selected from the group consisting of, any one of embodiments 1 to 9 of the camptothecin conjugate.

[0395] 13. The camptothecin conjugate of any one of embodiments 1 to 3 and 7, wherein D is CPT1.

[0396] 14. The camptothecin conjugate of any one of embodiments 1 to 3, wherein D is CPT2.

[0397] 15. The camptothecin conjugate of any one of embodiments 1 to 3, wherein D is CPT3.

[0398] 16. The camptothecin conjugate of any one of embodiments 1 to 3 and 8, wherein D is CPT4.

[0399] 17. The camptothecin conjugate of any one of embodiments 1 to 3, wherein D is CPT5.

[0400] 18. The camptothecin conjugate of any one of embodiments 1 to 3, 5, 6 and 9, wherein D is CPT6.

[0401] 18. The camptothecin conjugate of any one of embodiments 1 to 3, wherein D is CPT7.

[0402] 19. RL is the following formula:

Chemical formula

[0403] (In the formula, Su is a hexose form of a monosaccharide, particularly a glucuronic acid or mannose residue, O’ represents an oxygen atom of a glycoside bond that can be cleaved by glycosidase, and the wavy line marked with a single asterisk ( * ) represents R F and R F’A covalent bond site to the nitrogen atom of at least one primary or secondary aliphatic amino substituent of CPT1, CPT4, CPT6 where at least one is -H, or of 13b and 13c in Table H, 14a - 14f, 14i - 14o, 14s and 14u - 14z in Table I, and 18q and 18r in Table J, or to the spacer unit (Y), or a covalent bond site to the oxygen atom of a hydroxyl substituent on the lactone ring of any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or of 13a - 13c in Table H, and 14a - 14z in Table I, or 18a - 18r in Table J, indicated by a double asterisk ( ** ), and the wavy line marked with it indicates the covalent bond site to the remainder of Q) A camptothecin conjugate of any one of Embodiments 2 - 18, which is a glucuronide unit having

[0404] 20. Q is a linker unit having the formula -Z - A - RL - Y -, -Z - A - S * - RL - Y - or -Z - A - B(S * ), and the spacer unit (Y) has the following formula:

Chemical formula

[0405] (wherein EWG is an electron-withdrawing group, O * represents an oxygen atom derived from a hydroxy substituent of D, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to O * indicates the covalent bond site to the remainder of D) A camptothecin conjugate of Embodiment 19, having

[0406] 21. Q is a linker unit having the formula -Z - A - RL - Y -, -Z - A - S * - RL - Y - or -Z - A - B(S * )- RL - Y -, D is R F and R F’Selected from the group consisting of CPT1, CPT4, and CPT6, each of which is -H, and the spacer unit (Y) has the following formula:

Chemical formula

[0407] (In the formula, EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates R F and R F’ each being -H, indicating the covalent bond site to the nitrogen atom of the amino substituent of CPT1, CPT4, or CPT6) The camptothecin conjugate of Embodiment 19 having

[0408] 22. Q is a linker unit having the formula -Z-A-RL-Y-, -Z-A-S * -RL-Y- or -Z-A-B(S * ))-RL-Y-, D is selected from the group consisting of CPT1, CPT4, and CPT6, each of R F and R F’ being -H, and the spacer unit (Y) has the following formula:

Chemical formula

[0409] (In the formula, EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates R F and R F’ each being -H, indicating the covalent bond site to the nitrogen atom of the amino substituent of CPT1, CPT4, or CPT6) The camptothecin conjugate of Embodiment 19 having

[0410] 23. A is a connector unit, and the connector unit (Uni) is a triazolyl moiety Comprising, wherein the triazole moiety is a precursor to the ligand unit of the conjugate of the alkynyl moiety of the drug linker compound, formed as necessary from the 1,3-dipolar cycloaddition of an azide substituent from a chemically modified target agent, a camptothecin conjugate according to any one of Embodiments 1 to 22.

[0411] 24. -Z-A- comprises a succinimidyl-alkanoyl moiety or a succinimidyl and triazolyl moiety, each optionally having a hydrolyzed form of the succinimide ring as a succinamide moiety, or a succinamide moiety derivable from the mDPR moiety of the camptothecin-linker compound, provided that when CPT1 has a covalent bond via the nitrogen atom of its amino substituent, -Z-A- comprises a succinimidyl and triazolyl moiety optionally having a hydrolyzed form of the succinimide ring as a succinamide moiety, or a succinamide moiety derivable from the mDPR moiety, a camptothecin conjugate according to any one of Embodiments 1 to 22.

[0412] 25. -Z-A- comprises a succinimidyl-alkanoyl-β-alanyl moiety optionally having a hydrolyzed form of the succinimide ring as a succinamide moiety, provided that when D is CPT1, D has a covalent bond to the oxygen atom of the hydroxyl substituent on its lactone ring, a camptothecin conjugate according to any one of Embodiments 1 to 22.

[0413] 26. -Z-A- comprises a succinamide moiety derivable from the mDPR moiety of the camptothecin-linker compound, a camptothecin conjugate according to any one of Embodiments 1 to 22.

[0414] 27. Q is of the following formula:

Chemical formula

[0415] or a salt thereof (wherein the succinimide ring is in a hydrolyzed form as a succinamide moiety, and the wavy line marked with a single asterisk ( * ) indicates a covalent bond site to the nitrogen atom of CPT1, CPT4 or CPT6 where R F and R F’ are -H, or to a spacer unit, and the wavy line marked with a triple asterisk ( *** ) indicates a covalent bond point to the sulfur atom of L) The camptothecin conjugate of Embodiment 26 having

[0416] 28. RL has the following structure:

Chemical formula

[0417] (wherein the wavy line marked with a single asterisk ( * ) indicates a covalent bond site to the oxygen atom of the hydroxyl substituent on the lactone ring of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or to the nitrogen atom of the amino substituent of CPT1, CPT4 or CPT6 where each of R F and R F’ is -H, or to a spacer unit (Y), and the wavy line marked with a double asterisk ( ** ) indicates a covalent bond site to A, B, S * or Z) The camptothecin conjugate of any one of Embodiments 2 to 26, which is a glucuronide unit having

[0418] 29. Q is a linker unit having a formula selected from the group consisting of -Z-A-S * -RL-; -Z-A-B(S * )-RL-; -Z-A-S * -RL-Y-; and -Z-A-B(S * )-RL-Y-, and -Z-A- contains a succinimide-propionyl moiety. The camptothecin conjugate of Embodiment 28.

[0419] 30. Q is of the following formula:

Chemical formula

[0420] (wherein the subscript n is an integer in the range of 1 to 50, the wavy line marked with a single asterisk ( * ) indicates a covalent bond site to D or the spacer unit (Y), and the wavy line marked with a triple asterisk ( *** ) indicates a covalent bond point to the sulfur atom of L) -Z-A-S having * -RL- is the camptothecin conjugate of Embodiment 29.

[0421] 31. The camptothecin conjugate of Embodiment 30, wherein the subscript n is 4.

[0422] 32. -Q-D has the following structure having a hydrolyzed form of a succinimide ring as a succinamide moiety, if necessary:

Chemical formula

[0423] or a salt thereof (wherein the wavy line indicates a covalent bond to the sulfur atom of the ligand unit) is the camptothecin conjugate of Embodiment 2.

[0424] 33. -Q-D has the following structure:

Chemical formula

[0425] or a salt thereof (wherein the wavy line indicates a covalent bond to the sulfur atom of the ligand unit and the succinimide ring is in a hydrolyzed form as a succinamide moiety) is the camptothecin conjugate of Embodiment 2.

[0426] 34. -Q-D has the following structure having a hydrolyzed form of a succinimide ring as a succinamide moiety, if necessary: [Chemical formula]

[0427] Or a salt thereof (wherein the wavy line indicates a covalent bond to the sulfur atom of the ligand unit), the camptothecin conjugate of Embodiment 2.

[0428] 35. L is a camptothecin conjugate of any one of Embodiments 1 to 34 derived from an antibody.

[0429] 36. The camptothecin conjugate of Embodiment 35, wherein the antibody specifically binds to an antigen selected from the group consisting of CD19, CD30, CD33, CD70 and LIV-1.

[0430] 37. Q is a linker unit having a formula selected from the group consisting of -Z-A-, -Z-A-S * -W- and -Z-A-B(S * )-W-, where A is a connector unit, or Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL, where A is a connector unit and RL is a releasable linker other than a glucuronide unit, the camptothecin conjugate of Embodiment 1.

[0431] 38. The camptothecin conjugate of Embodiment 37, wherein Q is a linker unit having the formula -Z-A-S * -W- or -Z-A-S * -W-RL-.

[0432] 39. Q is -Z-A-RL- or -Z-A-S *The camptothecin conjugate of embodiment 37, which is a linker unit having the formula -RL-.

[0433] 40. The camptothecin conjugate of embodiment 37, wherein Q is a linker unit having the formula -Z-A-.

[0434] 41. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT2.

[0435] 42. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT3.

[0436] 43. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT1.

[0437] 44. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT4.

[0438] 45. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT5.

[0439] 46. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT6.

[0440] 47. The camptothecin conjugate of any one of embodiments 37 to 40, wherein D is CPT7.

[0441] 48. Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-, -Z-A-S * -RL- and -Z-A-S * -W-RL-, wherein RL has the following formula:

Chemical formula

[0442] (In the formula, double asterisk (** ) The wavy line marked with () indicates the site of covalent bond to D, and the single asterisk ( * ) The wavy line marked with () indicates the covalent bond point to A, S * Or W), and is any one of the camptothecin conjugates of Embodiments 37 to 47.

[0443] 49. -Q-D is -Z-A-S * -W-RL-D, wherein D is R F And R F ' Each of which is -H having a covalent bond to the nitrogen atom of the amine substituent, and is CPT1, CPT4 or CPT6, and W is an amino acid unit selected from the group consisting of N-methyl-glycine (sarcosine), N-methyl-alanine, N-methyl-β-alanine, valine, N-methyl-valine, or D is CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7 having a covalent bond to the oxygen atom of the hydroxyl substituent on the lactone ring, and W is selected from the group consisting of glutamic acid or lysine The camptothecin conjugate of Embodiment 48, which is the selected amino acid unit.

[0444] 50. -Z-A- contains a succinimide-alkanoyl moiety or a succinimide and triazole moiety, each of which has a hydrolyzed form of a succinimide ring as a succinamide moiety, or a succinamide moiety derivable from mDPR of a camptothecin-linker compound as required, and is any one of the camptothecin conjugates of Embodiments 37 to 49.

[0445] 51. -Z-A- contains a succinimide-alkanoyl moiety having a hydrolyzed form of a succinimide ring as a succinamide moiety as required, and is any one of the camptothecin conjugates of Embodiments 37 to 49.

[0446] 52. A camptothecin conjugate according to any one of embodiments 37 to 49, wherein -Z-A- comprises a succinamide moiety derivable from the mDPR moiety of a camptothecin-linker compound.

[0447] 53. Q is -Z-A-S * -RL- and -Z-A-S * A linker unit having a formula selected from the group consisting of -W-RL-, wherein -Z-A- optionally has a hydrolyzed form of a succinimide ring as the succinamide moiety, as follows:

Chemical formula

[0448] (In the formula, the wavy line marked with a double asterisk ( ** ) indicates the covalent bond site to S * , and the wavy line marked with a triple asterisk ( *** ) indicates the covalent bond point to the sulfur atom of L) A camptothecin conjugate according to any one of embodiments 37 to 49 having a formula selected from the group consisting of.

[0449] 54. Q is a linker unit having a formula selected from the group consisting of -Z-A-S * -RL- and -Z-A-S * -W-RL-, wherein S * has the following formula:

Chemical formula

[0450] (In the formula, the subscript n is an integer in the range of 2 to 36) A camptothecin conjugate according to any one of claims 37 to 49.

[0451] 55. -Z A- optionally has a hydrolyzed form of a succinimide ring as the succinamide moiety, having the following formula:

Chemical formula

[0452] (wherein the wavy line marked with a double asterisk ( ** ) indicates the site of covalent bond to S * , and the wavy line marked with a triple asterisk ( *** ) indicates the point of covalent bond to the sulfur atom of L) having any one of the camptothecin conjugates of claims 37 to 49.

[0453] 56. Q is a linker unit of the formula -Z-A-S * -W- or -Z-A-S-W-RL-, RL is other than a glucuronide unit, and -Z-A-S * -W- in any of the formulas has a hydrolyzed form of a succinimide ring as a succinamide moiety as required, of the following formula:

Chemical formula

[0454] (wherein the subscript n is an integer in the range of 2 to 10, and the wavy line marked with a double asterisk ( ** ) indicates the site of covalent bond to D or RL, and the wavy line marked with a triple asterisk ( *** ) indicates the point of covalent bond to the sulfur atom of L) having any one of the camptothecin conjugates of claims 37 to 49.

[0455] 57. The camptothecin conjugate of embodiment 56, wherein the subscript n is an integer in the range of 2 to 4.

[0456] 58. -Q-D has the following structure having a hydrolyzed form of a succinimide ring as a succinamide moiety as required:

Chemical formula

[0457] Or a salt thereof (wherein the wavy line indicates the point of covalent bond to the sulfur atom of the ligand unit) having the camptothecin conjugate of embodiment 49.

[0458] 59. -Q-D has the following structure having a hydrolyzed form of a succinimide ring as a succinamide moiety, if necessary:

Chemical formula

[0459] or a salt thereof (wherein the wavy line indicates the point of covalent bond to the sulfur atom of the ligand unit), the camptothecin conjugate of Embodiment 49.

[0460] 60. The camptothecin conjugate of any one of Embodiments 37 to 59, wherein L is an antibody.

[0461] 61. The camptothecin conjugate of Embodiment 60, wherein the antibody specifically binds to an antigen selected from the group consisting of CD19, CD30, CD33, CD70, and LIV-1.

[0462] 62. A camptothecin-linker compound having a formula selected from the group consisting of Z’-A-RL-D(i), Z’-A-RL-Y-D(ii), Z’-A-S * -RL-D(iii), -Z’-A-S * -RL-Y-D(iv), Z’-A-B(S * )-RL-D(v), Z’-A-B(S * )-RL-Y-D(vi), Z’-A-D(vii), Z’-A-S * -W-D(viii), Z’-A-B(S * )-W-D(ix), Z’-A-S * -W-RL-D(x) and Z’-A-B(S * )-W-RL-D(xi), wherein in each formula, Z’ is a stretcher unit precursor, A is a bond or a connector unit, B is a parallel connector unit, S * is a distributor, RL is a cleavable linker, Y is a spacer unit, and D is the following:

Chemical formula

Chem.

[0463] (wherein, R B is a member selected from the group consisting of -H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-, R C is a moiety selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each independently -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)-amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-C1-C4 hydroxyalkyl-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkylC(O)-, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C 10 heterocycloalkyl)- C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl-C1-C4 alkyl-, heteroaryl and heteroaryl-C1-C4 alkyl- or R F and R F’ together with the nitrogen atom to which each is attached form a 5-, 6- or 7-membered ring having 0 to 3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, R B 、RC , R F and R F’ The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of and are substituted with 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2), a camptothecin compound selected from the group consisting of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7 as described, or

[0464] D is a drug unit selected from the group consisting of 13a-13c of Table H, 14a-14z of Table I, and 18a-18r of Table J,

[0465] When the covalent bond point of D is such that Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- or -Z-A-B(S * )-RL-Y-, it is to any one of the heteroatoms of any one hydroxyl or aliphatic primary or secondary amino substituent of any one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7, or any one of 13a-13c of Table H, 14a-14z of Table I, and 18a-18r of Table J, or

[0466] When the covalent bond point of D is such that Q is -Z-A-, -Z-A-S * -W- or -Z-A-B(S * )-W-, or when Q is -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- or -Z-A-B(S *)-W-RL- (where RL is a releasable unit other than a glucuronide unit), one of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or one of the hydroxyl substituents on the lactone ring of 13a - 13c in Table H, 14a - 14z in Table I, and 18a - 18r in Table J, with respect to the oxygen atom,

[0467] provided that when the covalent bond point is with respect to the nitrogen atom of the amino substituent of CPT6, R F and R F’ at least one of which is -H, provided that when D is CPT1 having a covalent bond through the nitrogen atom of its amino substituent, Z’-A- of the camptothecin-linker compound of formula (i), formula (ii), formula (iii), formula (iv), formula (v) and formula (vi) is other than a maleimide-caproyl-β-alanyl moiety, a camptothecin-linker compound.

[0468] 63. A camptothecin-linker compound of embodiment 62 having a formula selected from the group consisting of formula (i), formula (ii), formula (iii), formula (iv), formula (v) and formula (vi), wherein A is a linker unit and RL is a glucuronide unit, a camptothecin-linker compound.

[0469] 64. The camptothecin-linker compound of embodiment 62 or 63, wherein the covalent bond point of D is through the oxygen atom of a hydroxyl substituent on the lactone ring of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7.

[0470] 65. The camptothecin-linker compound of embodiment 62 or 63, wherein the covalent bond point of D is through the oxygen atom of a hydroxyl substituent on the lactone ring of any one of 13a - 13c in Table H, 14a - 14z in Table I, and 18a - 18n in Table J to be, a camptothecin-linker compound of embodiment 62 or 63.

[0471] 66. R F and R F’When at least one of them is C1-C8 hydroxyalkyl N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)-amino-C1-C8 alkyl-, N-C1-C4 hydroxyalkyl-C1-C8 aminoalkyl-, C1-C8 alkyl C(O)-, the covalent bond point of D is the R of CPT6 F or R F’ The camptothecin-linker compound of Embodiment 62 or 63, wherein it is via the oxygen atom of the hydroxyl substituent of.

[0472] 67. R F and R F’ When at least one of them is C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N-(C1-C4 hydroxyalkyl)-C1-C8 aminoalkyl- or C1-C8 aminoalkyl C(O)-, the covalent bond point of D is the R of CPT6 F or R F’ The camptothecin-linker compound of Embodiment 62 or 63, wherein it is via the nitrogen atom of the amine substituent of.

[0473] 68. The covalent bond point of D is via the nitrogen atom of the amino substituent of CPT1, provided that Z'-A- is other than maleimide-caproyl-β-alanine, the camptothecin-linker compound of Embodiment 62 or 63.

[0474] 69. The covalent bond point of D is for the nitrogen atom of the amino substituent of CPT4, the camptothecin-linker compound of Embodiment 62 or 63.

[0475] 70. The covalent bond point of D is via the nitrogen atom of the substituent of CPT6, provided that F and R F’ The camptothecin-linker compound of Embodiment 62 or 63, provided that at least one of them is -H.

[0476] 71. The camptothecin-linker compound of any one of Embodiments 62-70 having formula (i) or (ii).

[0477] 72. A camptothecin-linker compound of any one of Embodiments 62 to 70 having formula (iii) or (iv).

[0478] 73. A camptothecin-linker compound of any one of Embodiments 62 to 70 having formula (v) or (vi).

[0479] 74. A camptothecin-linker compound of any one of Embodiments 62 to 70 having formula (i).

[0480] 75. A camptothecin-linker compound of any one of Embodiments 62 to 70 having formula (ii).

[0481] 76. A camptothecin-linker compound of any one of Embodiments 62 to 64, 66, 67 and 70 to 75, wherein D is CPT6.

[0482] 77. A camptothecin-linker compound of any one of Embodiments 62 to 64, 69 and 71 to 75, wherein D is CPT4.

[0483] 78. A camptothecin-linker compound of any one of Embodiments 62 to 64 and 71 to 75, wherein D is selected from the group consisting of CPT1, CPT2, CPT3 and CPT5.

[0484] 79. A camptothecin-linker compound of any one of Embodiments 62 to 78, wherein Z’ is a maleimide moiety.

[0485] 80. Z'-A- is maleimidopropionyl, maleimidopropionyl-β-alanyl or mDPR, and its basic nitrogen is optionally protonated or protected by an acid-labile protecting group, provided that when D is CPT1 having a covalent bond through the nitrogen atom of its amino substituent, Z'-A- is other than the maleimide-caproyl-β-alanyl moiety, a camptothecin-linker compound of any one of embodiments 62 to 78.

[0486] 81. S * is a PEG group, a camptothecin-linker compound of any one of embodiments 62 to 70 having formula (iii), formula (iv), formula (v) and formula (vi).

[0487] 82. RL has the following structure:

Chemical formula

[0488] (wherein the wavy line marked with a single asterisk ( * ) indicates the covalent bond site to D or the spacer unit (Y), and the wavy line marked with a double asterisk ( ** ) indicates the covalent bond point to A, B or S * ).) is a glucuronide unit having, a camptothecin-linker compound of any one of embodiments 63 to 81.

[0489] 83. The spacer unit (Y) has the following formula:

Chemical formula

[0490] (wherein EWG is an electron-withdrawing group, O * represents an oxygen atom derived from the hydroxy substituent of D, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to O * indicates the covalent bond site to the remainder of D.) A camptothecin-linker compound of Embodiment 82 having formula (ii), formula (iv) or formula (vi), having .

[0491] 84. D is selected from the group consisting of CPT1, CPT4 and CPT6, wherein each of R F and R F’ is -H, and the spacer unit (Y) has the following formula:

Chemical formula

[0492] (wherein EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates the covalent bond site to the nitrogen atom of the amino substituent of CPT1, CPT4 or CPT6, wherein each of R F and R F’ is -H). A camptothecin-linker compound of Embodiment 82 having formula (ii), formula (iv) or formula (vi), having .

[0493] 85. D is selected from the group consisting of CPT1, CPT4 and CPT6, wherein each of R F and R F’ is -H, and the spacer unit (Y) has the following formula:

Chemical formula

[0494] (wherein EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates the covalent bond site to the nitrogen atom of the amino substituent of CPT1, CPT4 or CPT6, wherein each of R F and R F’ is -H). A camptothecin-linker compound of Embodiment 82 having formula (ii), formula (iv) or formula (vi), having .

[0495] 86. A camptothecin-linker compound according to any one of embodiments 62 to 85, which contains an alkynyl moiety capable of undergoing a 1,3-dipolar cycloaddition with an azide substituent derived from a chemically modified targeting agent such that the targeting agent is a precursor to a ligand unit of a camptothecin conjugate that results in a conjugate having a linker unit containing a triazolyl moiety.

[0496] 87. A camptothecin-linker compound according to any one of embodiments 62 to 85, wherein Z'-A- contains a maleimide-alkanoyl moiety or a maleimide and a triazolyl moiety, provided that when CPT1 has a covalent bond through the nitrogen atom of its amino substituent, Z'-A- contains a maleimide and a triazolyl moiety.

[0497] 88. A camptothecin-linker compound according to any one of embodiments 62 to 85, wherein when D is CPT1, D has a covalent bond to the oxygen atom of the hydroxyl substituent on its lactone ring, and Z'-A- contains a maleimide-alkanoyl-β-alanyl moiety.

[0498] 89. A camptothecin-linker compound according to any one of embodiments 58 to 79, wherein Z'-A- contains mDPR, and its basic nitrogen atom is optionally protonated or protected by an acid-labile protecting group.

[0499] 90. A camptothecin-linker compound according to embodiment 62, which has formula (vii), formula (viii) or formula (ix) where A is a linker unit, or which has formula (i), formula (iii), formula (x) or formula (xi) where A is a linker unit and RL is a releasable linker other than a glucuronide unit.

[0500] 91. A camptothecin-linker compound according to embodiment 62 or 90, which has formula (viii) or formula (x).

[0501] 92. A camptothecin-linker compound of Embodiment 62 or 90 having formula (i) or formula (iii).

[0502] 93. A camptothecin-linker compound of Embodiment 62 or 90 having formula (vii).

[0503] 94. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT2.

[0504] 95. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT3.

[0505] 96. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT1.

[0506] 97. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT4.

[0507] 98. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT5.

[0508] 99. A camptothecin-linker compound of any one of Embodiments 62 and 90 - 93, wherein D has formula CPT6.

[0509] 100. RL has the following formula:

Chemical formula

[0510] (In the formula, the wavy line marked with a double asterisk ( ** ) indicates the covalent bond site to D, and the wavy line marked with a single asterisk ( * ) indicates A, S *A camptothecin-linker compound of any one of embodiments 62 and 90-99 having formula (i), formula (iii) or formula (x) (showing a covalent bond to W or).

[0511] 101. The camptothecin-linker compound of embodiment 100 having formula (x), wherein W is an amino acid unit selected from the group consisting of N-methyl-glycine (sarcosine), N-methyl-alanine, N-methyl-β-alanine, valine and N-methyl-valine.

[0512] 102. Z'-A- contains a maleimide-alkanoyl moiety, maleimide and triaz -ol moiety or mDPR, and its basic nitrogen atom is optionally protonated or protected by an acid-labile protecting group. The camptothecin-linker compound of any one of embodiments 62-101.

[0513] 102. The camptothecin-linker compound of any one of embodiments 62-101, wherein Z'-A- contains a maleimide-alkanoyl moiety.

[0514] 103. The camptothecin-linker compound of any one of embodiments 62-101, wherein Z'-A- contains mDPR.

[0515] 104. Z'-A- is as follows:

Chemical formula

[0516] (In the formula, the wavy line marked with a double asterisk ( ** ) indicates the covalent bond site to S * ).) A camptothecin-linker compound of formula (iii) or formula (x) having a formula selected from the group consisting of, of embodiments 62-70.

[0517] 105. S * is the following formula: [Chemical]

[0518] (wherein the subscript n is an integer in the range of 2 to 36) A camptothecin-linker compound having the formula (iii) or formula (x) and having any one of Embodiments 62 to 70 and 94 to 104.

[0519] 106. Z'-A- is the following formula: [Chemical]

[0520] (wherein the double asterisk ( ** )-marked wavy line indicates the covalent bond site to S * )). A camptothecin-linker compound having any one of Embodiments 62 to 70 and 94 to 105.

[0521] 107. Z'-A-S * -W- is the following formula: [Chemical]

[0522] (wherein the subscript n is an integer in the range of 2 to 10, the double asterisk ( ** )-marked wavy line indicates the covalent bond site to D or RL, and the triple asterisk ( *** )-marked wavy line indicates the covalent bond point to the sulfur atom of L). A camptothecin-linker compound having the formula (viii) or formula (x) and having any one of Embodiments 62 to 70 and 94 to 105.

[0523] 108. A camptothecin-linker compound according to Embodiment 107, wherein the subscript n is an integer in the range of 2 to 4.

[0524] 109. The following structure: [Chem.] A camptothecin-linker compound of Embodiment 62 having or a salt thereof.

[0525] 110. The following structure: [Chem.]

[0526] A camptothecin-linker compound of Embodiment 62 having or a salt thereof.

[0527] 111. The following structure: [Chem.]

[0528] A camptothecin-linker compound of Embodiment 62 having or a salt thereof.

[0529] 112. The following structure: [Chem.]

[0530] A camptothecin-linker compound of Embodiment 62 having or a salt thereof.

[0531] 113. The following structure: [Chem.]

[0532] A camptothecin-linker compound of Embodiment 62 having or a salt thereof.

[0533] 114. Use of a camptothecin conjugate in the preparation of a medicament for treating cancer in a subject, wherein the camptothecin conjugate has one of the formulas of Embodiments 1 to 113.

[0534] 115. Use according to embodiment 114, wherein the cancer is selected from the group consisting of lymphoma, leukemia and solid tumors.

[0535] 116. Use according to embodiment 114, wherein the cancer is lymphoma or leukemia.

[0536] 117. Use of a camptothecin conjugate in the preparation of a medicament for treating an autoimmune disease in a subject, wherein the camptothecin conjugate has one of the formulas of embodiments 1 to 113, and the autoimmune disease is selected from the group consisting of Th2 lymphocyte-related disorders, Th1 lymphocyte-related disorders and activated B lymphocyte-related disorders.

[0537] 118. A method for preparing a camptothecin conjugate according to any one of embodiments 1 to 61, the method comprising contacting an antibody having a functional group reactive with Z' of a camptothecin-linker compound according to any one of embodiments 62 to 113.

[0538] 1A. A camptothecin conjugate having the formula L-(Q-D) p or a salt thereof, wherein L is a ligand unit, Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- and -Z-A-B(S * )-RL-Y-, Z is a stretcher unit, A is a bond or connector unit, B is a parallel connector unit, S * is a distributor, RL is a glucuronide unit, Y is a spacer unit, and D is the following:

Chemical formula

[0539] (wherein, R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, C3-C8 cycloalkyl C1-C4 alkyl, phenyl and phenyl C1-C4 alkyl, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each independently a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, C1-C4 alkylamino C1-C8 alkyl, (C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino C1-C8 alkyl, di(C1-C4 alkyl)amino C1-C8 alkyl, C1-C4 hydroxyalkyl C1-C8 aminoalkyl, C1-C8 alkyl C(O)-, C1-C8 hydroxyalkyl C(O)-, C1-C8 aminoalkyl C(O)-, C3-C 10 cycloalkyl, C3-C 10 cycloalkyl C1-C4 alkyl, C3-C 10 heterocycloalkyl, C3-C 10 heterocycloalkyl C1-C4 alkyl, phenyl, phenyl C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl C1-C4 alkyl, or R F and R F’ together with the nitrogen atom to which each is attached form a 5-, 6- or 7-membered ring having 0 to 3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, R B , R C , R F and R F’The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties are substituted with 0 to 3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, and the subscript p is an integer from 1 to 16), and is a drug unit selected from the group consisting of

[0540] Q is present in CPT1, CPT2, CPT3, CPT4, CPT5 or CPT6 is bonded via either a hydroxyl or an amine group, and when D is CPT1 having a bond via the amino group of CPT1, -Z-A- is other than maleimide-caproyl-β-alanine, a camptothecin conjugate.

[0541] 2A. The camptothecin conjugate of Embodiment 1A, wherein Q is a linker unit having a formula selected from the group consisting of -Z-A-RL- and -Z-A-RL-Y-.

[0542] 3A. Q is -Z-A-S * -RL- and -Z-A-S * -RL-Y- is a linker unit having a formula selected from the group consisting of, the camptothecin conjugate of Embodiment 1A.

[0543] 4A. Q is -Z-A-B(S * )-RL- and -Z-A-B(S * )-RL-Y- is a linker unit having a formula selected from the group consisting of, the camptothecin conjugate of Embodiment 1A.

[0544] 5A. The camptothecin conjugate of any one of Embodiments 1A to 4A, wherein D has the formula CPT1.

[0545] 6A. The camptothecin conjugate of any one of Embodiments 1A to 4A, wherein D has the formula CPT2.

[0546] 7A. A camptothecin conjugate of any one of Embodiments 1A - 4A, wherein D has the formula CPT3.

[0547] 8A. A camptothecin conjugate of any one of Embodiments 1A - 4A, wherein D has the formula CPT4.

[0548] 9A. A camptothecin conjugate of any one of Embodiments 1A - 4A, wherein D has the formula CPT5.

[0549] 10A. A camptothecin conjugate of any one of Embodiments 1A - 4A, wherein D has the formula CPT6.

[0550] 11A. A camptothecin conjugate of any one of Embodiments 1A - 4A, wherein L is an antibody.

[0551] 12A. Q has the following formula:

Chemical formula

[0552] (wherein the sugar is a hexose form of a natural or non - natural monosaccharide, RL is bonded to the primary amine of any one of CPT1, CPT4 or CPT6, and the single * wavy line marked indicates the site of binding to the primary amine of CPT1, CPT4 or CPT6, or to the spacer unit (Y), ** and the wavy line marked indicates the binding point to the additional linker component of Q )( A camptothecin conjugate of Embodiment 1A, comprising a glucuronide unit (RL) having the above formula (wherein the sugar is a hexose form of a natural or non - natural monosaccharide, RL is bonded to the primary amine of any one of CPT1, CPT4 or CPT6, and the single wavy line marked indicates the site of binding to the primary amine of CPT1, CPT4 or CPT6, or to the spacer unit (Y), and the wavy line marked indicates the binding point to the additional linker component of Q).

[0553] 13A. The spacer unit (Y) is present and is as follows:

Chemical formula

[0554] (wherein EWG is an electron-withdrawing group) The camptothecin conjugate of Embodiment 12A comprising .

[0555] 14A. The camptothecin conjugate of Embodiment 12A, wherein A comprises a triazole formed from an alkyne and an azide using click chemistry.

[0556] 15A. The camptothecin conjugate of Embodiment 12A, wherein -Z-A- comprises a maleimide-alkanoic acid component, a maleimide and triazole component, or an mDPR component.

[0557] 16A. The camptothecin conjugate of Embodiment 12A, wherein -Z-A- comprises a maleimide-alkanoyl-β-alanyl component.

[0558] 17A. The camptothecin conjugate of Embodiment 12A, wherein Z-A- comprises an mDPR component.

[0559] 18A. Q has the following formula:

Chemical formula

[0560] (wherein the single * -marked wavy line indicates the site of attachment to the primary amine of CPT1, CPT4 or CPT6, or to the spacer unit, and *** -marked wavy line indicates the point of attachment to the sulfur atom of L) The camptothecin conjugate of Embodiment 12A having .

[0561] 19A. The glucuronide unit has the following formula:

Chemical formula

[0562] (wherein the single *The wavy lines marked with are the attachment points to the hydroxyl groups of CPT1, CPT2, CPT3, CPT4, CPT5 or CPT6, or to the spacer unit (Y), ** The wavy lines marked with are A, B, S * or the attachment points to Z) The camptothecin conjugate of Embodiment 1A having.

[0563] 20A. There is a spacer unit, as follows:

Chemical formula

[0564] (In the formula, EWG is an electron-withdrawing group) The camptothecin conjugate of Embodiment 19A containing.

[0565] 21A. There is a spacer unit, as follows:

Chemical formula

[0566] 22A. The camptothecin conjugate of Claim 19A, wherein A contains a triazole formed from an alkyne and an azide using click chemistry.

[0567] 23A. The camptothecin conjugate of Claim 19A, wherein -Z-A- contains a maleimide-alkanoic acid component, a maleimide and a triazole component or an mDPR component.

[0568] 24A. The camptothecin conjugate of Embodiment 19A, wherein -Z-A- contains a maleimide-alkanoyl-β-alanyl component.

[0569] 25A. The camptothecin conjugate of Embodiment 19A, wherein -Z-A- contains an mDPR component.

[0570] 26A. -Z-A- contains a maleimidopropionyl component, and the distributor (S * ) is present in the linker unit, the camptothecin conjugate of Embodiment 19A.

[0571] 27A. Q has the following formula:

Chemical formula

[0572] (wherein n is an integer from 1 to 50, and the single * wavy line marked with a dot indicates the site of attachment to D or the spacer unit (Y), *** and the wavy line marked with a dot indicates the point of attachment to the sulfur atom of L) having the camptothecin conjugate of Embodiment 19A.

[0573] 28A. The camptothecin conjugate of Embodiment 27A, wherein n is 4.

[0574] 29A. The camptothecin conjugate of any one of Embodiments 1A to 28A, wherein L is an antibody that specifically binds to an antigen selected from the group consisting of CD19, CD30, CD33, CD70, and LIV-1.

[0575] 30A. A camptothecin-linker compound having a formula selected from the group consisting of Z’-A-RL-D(i), Z’-A-RL-Y-D(ii), Z’-A-S * -RL-D(iii), Z’-A-S * -RL-Y-D(iv), Z’-A-B(S * )-RL-D(v), and Z’-A-B(S * )-RL-Y-D(vi), wherein Z’ is a stretcher unit, A is a linker or connector unit, B is a parallel connector unit, S * is a distributor, RL is a glucuronide unit, Y is a spacer unit, and D is as follows:

Chemical formula

[0576] (R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, C3-C8 cycloalkyl C1-C4 alkyl, phenyl and phenyl C1-C4 alkyl, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each independently -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, C1-C4 alkylamino C1-C8 alkyl, (C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino C1-C8 alkyl, di(C1-C4 alkyl)amino C1-C8 alkyl, C1-C4 hydroxyalkyl C1-C8 aminoalkyl, C1-C8 alkyl C(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkyl C(O)-, C3-C 10 cycloalkyl, C3-C 10 cycloalkyl C1-C4 alkyl, C3-C 10 heterocycloalkyl, C3-C 10 heterocycloalkyl C1-C4 alkyl, phenyl, phenyl C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl C1-C4 alkyl, or R F and R F’ together with the nitrogen atom to which each is attached form a 5-, 6- or 7-membered ring having 0-3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, NHC1-C4 alkyl and N(C1-C4 alkyl)2, R B R C R F and R F’The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties are substituted with 0 to 3 substituents selected from halogen, C1-C4 alkyl, OH, OC1-C4 alkyl, NH2, NHC1-C4 alkyl and N(C1-C4 alkyl)2) which is a camptothecin compound selected from the group consisting of

[0577] wherein the subscript p is an integer from 1 to 16, Q is bonded via either a hydroxyl or an amine group present in CPT1, CPT2, CPT3, CPT4, CPT5 or CPT6, and when D is CPT1 having a bond via the amino group of CPT1, -Z-A- is other than maleimide-caproyl-β-alanyl, a camptothecin-linker compound.

[0578] 31A. A camptothecin-linker compound of embodiment 30A having formula (i) or (ii).

[0579] 32A. A camptothecin-linker compound of embodiment 30A having formula (iii) or (iv).

[0580] 33A. A camptothecin-linker compound of embodiment 30A having formula (v) or (vi).

[0581] 34A. A camptothecin-linker compound of embodiment 30A having formula (i).

[0582] 35A. A camptothecin-linker compound of embodiment 30A having formula (ii).

[0583] 36A. A camptothecin-linker compound of any one of embodiments 30A to 34A, wherein D is CPT6.

[0584] 37A. A camptothecin-linker compound of any one of embodiments 30A to 34A, wherein D is CPT4.

[0585] 38A. A camptothecin-linker compound according to any one of embodiments 30A to 34A, wherein D is selected from the group consisting of CPT1, CPT2, CPT3 and CPT5.

[0586] 39A. A camptothecin-linker compound according to any one of embodiments 30A to 34A, wherein Z' is a maleimide group.

[0587] 40A. A camptothecin-linker compound according to any one of embodiments 30A to 34A, wherein Z'-A- is maleimidopropionyl, mDPR or maleimidopropionyl-β-alanyl.

[0588] 41A. S * is a PEG group, and is a camptothecin-linker compound according to any one of embodiments 30A and 32A to 34A.

[0589] 42A. The glucuronide unit has the following formula:

Chemical formula

[0590] (wherein the single * wavy line marked with indicates the site of attachment to D or the spacer unit (Y), ** the wavy line marked with indicates the attachment point to the additional linker components A, B, S * or Z' of the camptothecin-linker compound) and is a camptothecin-linker compound of embodiment 30A.

[0591] 42A. A spacer unit is present and is as follows:

Chemical formula

[0592] (wherein EWG is an electron-withdrawing group) and is a camptothecin-linker compound of embodiment 30A.

[0593] 43A. There is a spacer unit, as follows: [Chemical formula] A camptothecin-linker compound of embodiment 42A, comprising:

[0594] 44A. A camptothecin-linker compound of embodiment 42A, wherein A comprises a triazole formed from an alkyne and an azide using click chemistry.

[0595] 45A. A camptothecin-linker compound of embodiment 42A, wherein Z'-A- comprises a maleimide-alkanoic acid component, a maleimide and triazole component, or an mDPR component.

[0596] 46A. A camptothecin-linker compound of embodiment 42A, wherein Z'-A- comprises a maleimide-alkanoyl-β-alanyl component.

[0597] 47A. A camptothecin-linker compound of embodiment 42A, wherein Z'-A- comprises an mDPR component.

[0598] 48A. A camptothecin-linker compound of embodiment 42A, wherein Z'-A- comprises a maleimidopropionyl component and a dispenser (S * ) is present in the linker unit.

[0599] 49A. Formulas (i) and (ii) are the following formulas: [Chemical formula]

[0600] (wherein the wavy line marked with a single * indicates the site of attachment to the primary amine of CPT1, CPT4 or CPT6, or to the spacer unit) A camptothecin-linker compound of embodiment 30A, comprising:

[0601] 50A. A method for treating cancer in a subject in need thereof, the method comprising administering to the subject any one of the camptothecin conjugates of Embodiments 1A-29A.

[0602] 51A. The method of Embodiment 50A, wherein the cancer is selected from the group consisting of lymphoma, leukemia, and solid tumors.

[0603] 52A. The method of Embodiment 50A, wherein the cancer is lymphoma or leukemia.

[0604] 53A. The method of any one of Embodiments 50A-53A, further comprising an additional therapeutic agent.

[0605] 54A. The method of Embodiment 53A, wherein the additional therapeutic agent is one or more chemotherapeutic agents or radiation therapy.

[0606] 55A. A method for treating an autoimmune disease in a subject in need thereof, the method comprising administering to the subject any one of the camptothecin conjugates of Embodiments 1A-29A.

[0607] 56A. The method of Embodiment 55A, wherein the autoimmune disease is selected from the group consisting of Th2 lymphocyte-related disorders, Th1 lymphocyte-related disorders, and activated B lymphocyte-related disorders.

[0608] 57A. A method for preparing any one of the camptothecin conjugates of Embodiments 1A-29A, the method comprising reacting an antibody with any one of the camptothecin-linker compounds of Embodiments 30A-49A.

[0609] 58A. A kit comprising any one of the camptothecin conjugates of Embodiments 1A-29A.

[0610] 59A. The kit of Embodiment 58A, further comprising an additional therapeutic agent.

[0611] 1B. L-(Q-D) formula p or a camptothecin conjugate having a salt thereof, wherein L is a ligand unit, Q is -Z-A-, -Z-A-RL-, -Z-A-S * -W-, -Z-A-B(S * )-W-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * )-W-RL- and is a linker unit having a formula selected from the group consisting of, Z is a stretcher unit, A is a linker or connector unit, B is a parallel connector unit, S * is a dispenser, RL is a releasable linker, W is an amino acid unit, D is as follows: [Chemical formula] [Chemical formula]

[0612] (wherein R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, C3-C8 cycloalkyl C1-C4 alkyl, phenyl and phenyl C1-C4 alkyl, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each, -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, C1-C4 alkylamino C1-C8 alkyl, (C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino C1-C8 alkyl, di(C1-C4 alkyl)amino C1-C8 alkyl, C1-C4 hydroxyalkyl C1-C8 aminoalkyl, C1-C8 alkyl C(O)-, C1-C8 hydroxyalkyl C(O)-, C1-C8 aminoalkyl C(O)-, C3-C 10Cycloalkyl, C3-C 10 Cycloalkyl C1-C4 alkyl, C3-C 10 Heterocycloalkyl, C3-C 10 A member independently selected from the group consisting of heterocycloalkyl C1-C4 alkyl, phenyl, phenyl C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl C1-C4 alkyl, or R F and R F’ and R B and R C and R F and R F’ together with the nitrogen atom to which each is attached, form a 5-membered, 6-membered or 7-membered ring having 0-3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, NHC1-C4 alkyl and N(C1-C4 alkyl)2, and the cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of R is a drug unit selected from the group consisting of

[0613] The point of attachment of D to Q is via the oxygen atom of the hydroxyl substituent of the lactone ring of CPT1, CPT2, CPT3, CPT4, CPT5 or CPT6. Camptothecin conjugate.

[0614] 2B. The camptothecin conjugate of Embodiment 1B, wherein Q is a linker unit having the formula -Z-A-S * -W-.

[0615] 3B. The camptothecin conjugate of Embodiment 1B, wherein Q is a linker unit having the formula -Z-A-S * -W-RL-.

[0616] 4B. The camptothecin conjugate of Embodiment 1B, wherein Q is a linker unit having the formula -Z-A-.

[0617] 5B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT2.

[0618] 6B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT3.

[0619] 7B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT1.

[0620] 8B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT4.

[0621] 9B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT5.

[0622] 10B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein D has the formula CPT6.

[0623] 11B. The camptothecin conjugate of any one of Embodiments 1B to 4B, wherein L is an antibody.

[0624] 12B. RL has the following formula:

Chemical formula

[0625] (wherein ** the wavy line marked with is the binding site to D, * the wavy line marked with is the binding point to another linker component of Q) The camptothecin conjugate of Embodiment 3B having.

[0626] 13B. The camptothecin conjugate of embodiment 12B, wherein W is an amino acid unit selected from the group consisting of N-methylglycine, N-methylalanine, N-methyl-β-alanine, valine, and N-methylvaline.

[0627] 14B. The camptothecin conjugate of embodiment 12B, wherein -Z-A- comprises a maleimide-alkanoyl moiety or a maleimide and triazole moiety or an mDPR moiety.

[0628] 15B. The camptothecin conjugate of embodiment 12B, wherein -Z-A- comprises a maleimide-alkanoyl moiety.

[0629] 16B. -Z-A- is as follows:

Chemical formula

[0630] (wherein, ** the wavy line marked with is the binding site to S * and the wavy line marked with is the binding point to the sulfur atom of L) *** (wherein the wavy line marked with is the binding site to S, and the wavy line marked with is the binding point to the sulfur atom of L) The camptothecin conjugate of embodiment 12B having a formula selected from the group consisting of.

[0631] 17B. S * has the following formula:

Chemical formula

[0632] The camptothecin conjugate of embodiment 12B, wherein the subscript n is an integer from 2 to 36.

[0633] 18B. The camptothecin conjugate of embodiment 2B, wherein W is an amino acid unit selected from the group consisting of N-methylglycine, N-methylalanine, N-methyl-β-alanine, valine, and N-methylvaline.

[0634] 19B. The camptothecin conjugate of embodiment 12B, wherein -Z-A- comprises a maleimide-alkanoyl moiety or a maleimide and triazole moiety or an mDPR moiety.

[0635] 20B. The camptothecin conjugate of embodiment 2B, wherein -Z-A- comprises a maleimide-alkanoyl moiety.

[0636] 21B. -Z-A- is as follows:

Chemical formula

[0637] (wherein ** the wavy line marked with is the bonding site to S * and the wavy line marked with is the bonding point to the sulfur atom of L) *** The camptothecin conjugate of embodiment 2B having a formula selected from the group consisting of

[0638] 22B. S * has the following formula:

Chemical formula

[0639] 23B. -Z-A- is as follows:

Chemical formula

[0640] (wherein ** the wavy line marked with is the bonding site to S * and the wavy line marked with is the bonding point to the sulfur atom of L) *** The camptothecin conjugate of embodiment 18B which is

[0641] 24B. Q has the following formula: [Chemical formula]

[0642] (wherein n is an integer from 2 to 10, ** The wavy line marked with is the binding site to D, *** The wavy line marked with indicates the binding point to the sulfur atom of L) The camptothecin conjugate of Embodiment 18B having

[0643] 25B. The camptothecin conjugate of Embodiment 27B, wherein n is 2 to 4.

[0644] 26B. The camptothecin conjugate of any one of Embodiments 1B to 25B, wherein L is an antibody that selectively binds to an antigen selected from the group consisting of CD19, CD30, CD33, CD70, and LIV-1.

[0645] 27B. A camptothecin-linker compound having a formula selected from the group consisting of Z’-A-D(i), Z’-A-RL-D(ii), Z’-A-S * -W-D(iii), Z’-A-S * -W-RL-D(iv), Z’-A-B(S * )-RL-D(v) and Z’-A-B(S * )-W-RL-D, wherein Z’ is a spacer unit, A is a linker or a connector unit, B is a parallel connector unit, S * is a distributor, RL is a releasable linker unit, and D is as follows: [Chemical formula] [Chemical formula]

[0646] (wherein R Bis a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, C3-C8 cycloalkyl C1-C4 alkyl, phenyl and phenyl C1-C4 alkyl, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each, -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, C1-C4 alkylamino C1-C8 alkyl, (C1-C4 hydroxyalkyl)(C1-C4 alkyl)amino C1-C8 alkyl, di(C1-C4 alkyl)amino C1-C8 alkyl, C1-C4 hydroxyalkyl C1-C8 aminoalkyl, C1-C8 alkyl C(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkyl C(O)-, C3-C 10 cycloalkyl, C3-C 10 cycloalkyl C1-C4 alkyl, C3-C 10 heterocycloalkyl, C3-C 10 heterocycloalkyl C1-C4 alkyl, phenyl, phenyl C1-C4 alkyl, diphenyl C1-C4 alkyl, heteroaryl and heteroaryl C1-C4 alkyl, or are members independently selected from the group consisting of

[0647] R F and R F’ together with the nitrogen atom to which each is attached form a 5-, 6- or 7-membered ring having 0-3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, NHC1-C4 alkyl and N(C1-C4 alkyl)2, R B R C R F and R F’the cycloalkyl, heterocycloalkyl, phenyl, and heteroaryl portions of R are substituted with 0-3 substituents selected from halogen, C1-C4 alkyl, OH, OC1-C4 alkyl, NH2, NHC1-C4 alkyl, and N(C1-C4 alkyl)2; B , R C , R F and R F’ Cycloalkyl, heterocycloalkyl, phenyl and heteroaryl The alkyl moiety is substituted with 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, OH, OC1-C4 alkyl, NH2, NHC1-C4 alkyl, and N(C1-C4 alkyl)2. A drug unit selected from the group consisting of

[0648] the point of attachment of D to Q is via the oxygen atom of the hydroxyl substituent of the lactone ring of CPT1, CPT2, CPT3, CPT4, CPT5 or CPT6; Camptothecin-linker compounds.

[0649] 28B. The camptothecin-linker compound of embodiment 27B having formula (i) or (ii).

[0650] 29B. The camptothecin-linker compound of embodiment 27B having formula (iii) or (iv).

[0651] 30B. The camptothecin-linker compound of embodiment 27B having formula (v) or (vi).

[0652] 31B. The camptothecin-linker compound of embodiment 27B having the formula (i).

[0653] 32B. The camptothecin-linker compound of embodiment 27B having the formula (ii).

[0654] 33B. The camptothecin-linker compound of any one of embodiments 27B-31B, wherein D is CPT2.

[0655] 34B. The camptothecin-linker compound of any one of Embodiments 27B to 31B, wherein D is CPT3.

[0656] 35B. The camptothecin-linker compound of any one of Embodiments 27B to 31B, wherein D is selected from the group consisting of CPT1, CPT4, CPT5, and CPT6.

[0657] 36B. The camptothecin-linker compound of any one of Embodiments 27B to 31B, wherein Z' is a maleimide group.

[0658] 37B. The camptothecin-linker compound of any one of Embodiments 27B to 31B, wherein Z'-A- is maleimidopropionyl, mDPR, or maleimidopropionyl-β-alanine.

[0659] 38B. S * is a PEG group, and the camptothecin-linker compound of any one of Embodiments 27B and 29B to 31B.

[0660] 39B. RL has the following formula:

Chemical formula

[0661] (In the formula, ** The wavy line marked with is the binding site to D, * The wavy line marked with is the binding point to another linker component of Q ). The camptothecin-linker compound of Embodiment 27B having this.

[0662] 40B. The camptothecin-linker compound of Embodiment 39B, wherein Z'-A- contains a maleimide-alkanoic acid moiety, or a maleimide and triazole moiety, or an mDPR moiety.

[0663] 41B. The camptothecin-linker compound of Embodiment 39B, wherein Z'-A- comprises a maleimide - alkanoyl - β - alanine component.

[0664] 42B. The camptothecin-linker compound of Embodiment 39B, wherein Z'-A- comprises an mDPR moiety.

[0665] 43B. The camptothecin-linker compound of Embodiment 39B, wherein Z'-A- comprises a maleimidopropionyl moiety and a dispensing agent (S * ) is present.

[0666] 44B. The following formula:

Chemical formula

[0667] 45B. The following formula:

Chemical formula

[0668] 46B. A method for treating cancer in a subject in need thereof, the method comprising administering to the subject a camptothecin conjugate of any one of Embodiments 1B - 29B.

[0669] 47B. The method of Embodiment 46B, wherein the cancer is selected from the group consisting of lymphoma, leukemia, and solid tumors.

[0670] 48B. The method of Embodiment 46B, wherein the cancer is lymphoma or leukemia.

[0671] 49B. The method of any one of Embodiments 46B - 48B, further comprising administering an additional therapeutic agent.

[0672] 50B. The method of embodiment 39B, wherein the additional therapeutic agent is one or more chemotherapeutic agents or radiation therapy.

[0673] 51B. A method of treating an autoimmune disease in a subject in need thereof, comprising administering to the subject any one of the camptothecin conjugates of embodiments 1B - 26B.

[0674] 52B. The method of embodiment 51B, wherein the autoimmune disease is selected from the group consisting of Th2 lymphocyte - related disorders, Th1 lymphocyte - related disorders, and activated B lymphocyte - related disorders.

[0675] 53B. A method of preparing any one of the camptothecin conjugates of embodiments 1B - 26B, comprising reacting an antibody having a free thiol with any one of the camptothecin - linker compounds of embodiments 27B - 43B.

[0676] 54B. A kit comprising any one of the camptothecin conjugates of embodiments 1B - 26B.

[0677] 55B. The kit of embodiment 54B, further comprising an additional therapeutic agent.

[0678] 1C. The following formula: L-(Q - D) p A camptothecin conjugate having

[0679] or a salt thereof [wherein L is a ligand unit derived from a targeting agent, in particular, an antibody that selectively binds to a cancer cell antigen, the subscript p is an integer in the range of 1 - 16, Q is -Z - A -, -Z - A - RL -, -Z - A - RL - Y -, -Z - A - S * - RL -, -Z - A - S * - RL - Y -, -Z - A - S * - W -, -Z - A - S * - W - RL -, -Z - A - B(S * ) - RL -, -Z - A - B(S* ) -W- and -Z-A-B(S * ) -W-RL- and -Z-A-B(S * ) a linker unit having a formula selected from the group consisting of -RL-Y-,

[0680] Z is a stretcher unit, A is a linking or connector unit, B is a parallel connector unit, S * is a dispenser, RL is a releasable linker, W is an amino acid unit, Y is a spacer unit, D is CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 and CPT7 as follows:

Chemical formula

Chemical formula

[0681] (wherein, R B is a member selected from the group consisting of H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)-C1-C4 alkyl-, phenyl and phenyl-C1-C4 alkyl-, R C is a member selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl, R F and R F’ are each, -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)-amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-C1-C4 hydroxyalkyl-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkylC(O)-, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10Heterocycloalkyl, (C3-C 10 heterocycloalkyl)-C1-C4alkyl-, phenyl, phenyl-C1-C4alkyl-, diphenyl-C1-C4alkyl-, heteroaryl and heteroaryl-C1-C4alkyl-, or R F and R F’ together with the nitrogen atom to which each is attached form a 5-, 6- or 7-membered ring having 0 to 3 substituents selected from halogen, C1-C4alkyl, -OH, -OC1-C4alkyl, -NH2, -NHC1-C4alkyl and -N(C1-C4alkyl)2, and the cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of R B , R C , R F and R F’ are substituted by 0 to 3 substituents selected from the group consisting of halogen, C1-C4alkyl, -OH, -OC1-C4alkyl, -NH2, -NHC1-C4alkyl and -N(C1-C4alkyl)2), or D is one of the camptothecin compounds of Tables H 13a-13c, Tables I 14a-14a, and Tables J 18a-18r,

[0682] when Q is -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y- or -Z-A-B(S * )-RL-Y-, the point of covalent attachment of D is to one of the heteroatoms of a hydroxyl or amino substituent at CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or one of Tables H 13a-13c, Tables I 14a-14a, and Tables J 18a-18r, or when Q is -Z-A-, -Z-A-S * -W- or -Z-A-B(S * )-W-, or when Q is -Z-A-S *-RL-, -Z-A-B(S * )-RL-, -Z-A-S * -W-RL- or -Z-A-B(S * )-W-RL- (where RL is a releasable unit other than a glucuronide unit), the covalent bond point of D is to the oxygen atom of a hydroxyl substituent on any one of the lactone rings of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6 or CPT7, or 13a - 13c of Table H, 14a - 14a of Table I, and 18a - 18r of Table J,

[0683] provided that when the covalent bond point is to the nitrogen atom of the amino substituent of CPT6, R F and R F’ at least one of which is -H, and when D is CPT1 having a covalent bond through the nitrogen atom of its amino substituent, -Z-A-RL-, -Z-A-RL-Y-, -Z-A-S * -RL-, -Z-A-B(S * )-RL-, -Z-A-S * -RL-Y and -Z-A-B(S * )-RL-Y, -Z-A- is other than the succinimide - caproyl - β - alanyl moiety optionally having a hydrolyzed form of a succinimide ring].

[0684] 2C. Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-; -Z-A-RL-Y-; -Z-A-S * -RL-; -Z-A-B(S * )-RL-; -Z-A-S * -RL-Y; and -Z-A-B(S * )-RL-Y, A is a connector unit, RL is a glucuronide unit, the camptothecin conjugate of Embodiment 1C.

[0685] 3C. The camptothecin conjugate of Embodiment 2C, wherein the covalent bond point of D is through the oxygen atom of a hydroxyl substituent on any one of the lactone rings of CPT1 - CPT7.

[0686] 4C. D is CPT1, CPT4, CPT6 or CPT7, and the covalent attachment point to CPT1 is via the nitrogen atom of its amine functional group, provided that -Z-A- is other than succinimide-caproyl-β-alanyl having a hydrolyzed form of a succinimide ring as a succinamide moiety as required,

[0687] the covalent attachment point to CPT4 is via the nitrogen atom of its amine functional group, the covalent attachment point to CPT6 is via the nitrogen atom of its amine functional group, provided that R F and R F’ at least one of which is -H, and the covalent attachment point to CPT7 is via one oxygen atom of its primary hydroxyl functional group, a camptothecin conjugate of embodiment 2C.

[0688] 5C. The glucuronide unit has the following formula:

Chemical formula

[0689] (wherein Su is a hexose form of a monosaccharide, O' represents an oxygen atom of a glycosidic bond that can be cleaved by a glycosidase, the wavy line marked with a single asterisk ( * ) indicates a covalent attachment site to the nitrogen atom of the amino substituent of CPT1, CPT4 or CPT6, or to the spacer unit (Y), where at least one of R F and R F’ is -H, or indicates a covalent attachment site to the oxygen atom of a hydroxyl substituent on the lactone ring of any one of CPT1 to CPT7, and the wavy line marked with a double asterisk ( ** ) indicates a covalent attachment site to the remainder of Q) has,

[0690] In particular, the glucuronide unit has the following formula:

Chemical formula

[0691] 6C. Q is -Z-A-RL-Y-, -Z-A-S * -RL-Y- or -Z-A-B(S * )-RL-Y- and is a linker unit, and the spacer unit (Y) has the following formula:

Chemical formula

[0692] (wherein EWG is an electron-withdrawing group, O * represents an oxygen atom derived from a hydroxy substituent of D, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and O * the wavy line adjacent to indicates the covalent bond site to the remainder of D) or

[0693] D is R F and R F’ each being -H, when it is CPT1, CPT4 or CPT6, the spacer unit (Y) has the following formula:

Chemical formula

[0694] (wherein EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates the covalent bond site to the nitrogen atom of the amino substituent of CPT1, CPT4 or CPT6), a camptothecin conjugate of Embodiment 5C.

[0695] 7C. -Z-A- contains a succinimide-alkanoyl moiety or a succinimide and triazolyl moiety, each having a hydrolyzed form of a succinimide ring as a succinamide moiety as required, and the triazole moiety is formed as required from a 1,3-dipolar cycloaddition of an azide substituent derived from a target agent that is chemically modified to an alkynyl moiety of a drug linker compound, and the target agent is a precursor to the ligand unit of the conjugate or

[0696] -Z-A- contains a succinamide moiety derivable from the mDPR moiety of a camptothecin-linker compound or contains a succinimide-propionyl moiety having a hydrolyzed form of a succinimide ring as required,

[0697] provided that D has a covalent bond through the nitrogen atom of its amino substituent and -Z-A- contains a succinimide and triazolyl moiety having a hydrolyzed form of a succinimide ring as a succinamide moiety as required, or when D is CPT1, contains a succinamide moiety derivable from the mDPR moiety, or D has a covalent bond to the oxygen atom of a hydroxyl substituent on its lactone ring and when D is CPT1, -Z-A- contains a succinimide-alkanoyl-β-alanyl moiety having a hydrolyzed form of a succinimide ring as a succinamide moiety as required, a camptothecin conjugate of embodiment 5C.

[0698] 8C. Q is of the following formula:

Chemical formula

[0699] or a salt thereof (-Z-A- is preferably a succinimide-alkanoyl-β-alanyl moiety in which its succinimide ring is in a hydrolyzed form as a succinamide moiety, the succinimide ring is derivable from the mDPR moiety of a camptothecin-linker compound, a single asterisk ( *) The wavy line marked with ) represents the oxygen atom of the hydroxyl functional group that replaces any one of the lactone rings of CPT1 to CPT7, to which R F and R F’ is -H, and represents the covalent bond site to the nitrogen atom of the amine functional group of CPT1, CPT4 or CPT6, or to the spacer unit. The wavy line marked with triple asterisk ( *** ) represents the covalent bond point to the sulfur atom of L), or

[0700] when Q is -Z-A-S * -RL, Q has the following formula, optionally having a hydrolyzed form of a succinimide ring as a succinamide moiety:

Chemical formula

[0701] (wherein the subscript n is an integer in the range of 1 to 50, preferably 4. The wavy line marked with a single asterisk ( * ) represents the covalent bond site to the heteroatom of any one of the hydroxyl or amine functional groups of CPT1 to CPT7, or to the spacer unit (Y). The wavy line marked with triple asterisk ( *** ) represents the covalent bond point to the sulfur atom of L) having the camptothecin conjugate of Embodiment 7C.

[0702] 9C. -Q-D has the following structure, optionally having a hydrolyzed form of a succinimide ring as a succinamide moiety:

Chemical formula

[0703] or a salt thereof (wherein the wavy line represents the covalent bond site of the succinimide ring to the sulfur atom of the ligand unit), or

[0704] -Q-D has the following structure:

Chemical formula

[0705] or has its salt, or -Q-D is the following structure

Chemical formula

[0706] or its salt (wherein the wavy line indicates the covalent bond site of the succinimide ring to the sulfur atom of the ligand unit, and the succinimide ring is in the hydrolyzed form as a succinamide moiety) The camptothecin conjugate of Embodiment 6C having

[0707] 10C. Q is a linker unit having a formula selected from the group consisting of -Z-A-; -Z-A-S * -W- and -Z-A-B(S * ))-W-, A is a connector unit, or Q is -Z-A-RL-, -Z-A-S * -RL-; -Z-A-B(S * ))-RL-, -Z-A-S * -W-RL- and -Z-A-B(S * ))-W-RL-, A is a connector unit, and RL is a releasable linker other than a glucuronide unit, the camptothecin conjugate of Embodiment 1C.

[0708] 11C. Q is a linker unit having a formula selected from the group consisting of -Z-A-RL-, -Z-A-S * -RL- and -Z-A-S * -W-RL-, RL is the following formula:

Chemical formula

[0709] (wherein the wavy line marked with a double asterisk ( ** )) indicates the covalent bond site to D, and the single asterisk ( *) The wavy line marked with is a covalent bond to A, S * or W) of the camptothecin conjugate of Embodiment 10C.

[0710] 12C. -Q-D is -Z-A-S * -W-RL-D, where D is R F and R F’ Each of which is CPT1, CPT4 or CPT6 where each is -H and each has a covalent bond to the nitrogen atom of the amine substituent, and W is an amino acid unit selected from the group consisting of N-methyl-glycine (sarcosine), N-methyl-alanine, N-methyl-β-alanine, valine, N-methyl-valine, or

[0711] D is any one of CPT1-CPT7 having a covalent bond to the oxygen atom of the hydroxyl substituent on the lactone ring, and W is an amino acid unit selected from the group consisting of glutamic acid or lysine, The camptothecin conjugate of Embodiment 10C or 11C.

[0712] 13C. -Z-A- contains a succinimide-alkanoyl moiety or a succinimide and triazole moiety, each of which optionally has a succinimide ring in hydrolyzed form as a succinamide moiety, or a succinamide moiety derivable from mDPR of the camptothecin-linker compound, or -Z-A optionally has a succinimide ring in hydrolyzed form as a succinamide moiety, the following formula:

Chemical formula

[0713] (wherein the wavy line marked with the double asterisk ( ** ) indicates a covalent bond to S * and the wavy line marked with the triple asterisk ( *** ) indicates a covalent bond to the sulfur atom of L) The camptothecin conjugate of Embodiment 12C having.

[0714] 14C. Q is -Z-A-S * -RL- and -Z-A-S * A linker unit having a formula selected from the group consisting of -W-RL-, wherein S * is the following formula:

Chemical formula

[0715] (In the formula, the subscript n is an integer in the range of 2 to 36, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of A, and the wavy line adjacent to the carbonyl carbon atom is -Z-A-S * the RL of -RL- or -Z-A-S * the covalent bond site to the nitrogen atom of the amine functional group of W of -W-RL-, and in particular, -Z A- in any of the formulas of Q is the following formula:

Chemical formula

[0716] (In the formula, the wavy line marked with a double asterisk ( ** )) indicates the covalent bond site to the nitrogen atom of the amine functional group of S * , and the wavy line marked with a triple asterisk ( *** )) indicates the covalent bond point to the sulfur atom of L) having) A camptothecin conjugate of Embodiment 11C having

[0717] 15C. Q is a linker unit of the formula -Z-A-S * -W- or -Z-A-S-W-RL-, and -Z-A-S * -W- in any of the formulas has a succinimide ring in hydrolyzed form as a succinamide moiety as required, the following formula:

Chemical formula

[0718] (In the formula, the subscript n is an integer in the range of 2 to 10, preferably in the range of 2 to 4, and the wavy line marked with double asterisks ( ** ) indicates the site of covalent bond to D or RL, and the wavy line marked with triple asterisks ( *** ) indicates the covalent bond point to the sulfur atom of L) The camptothecin conjugate of Embodiment 11C having

[0719] 16C. -Q-D has the following structure:

Chemical formula

[0720] 17C. A camptothecin-linker compound having a formula selected from the group consisting of: (i) Z’-A-RL-D; (ii) Z’-A-RL-Y-D; (iii) Z’-A-S * -RL-D; (iv) Z’-A-S * -RL-Y-D; (v) Z’-A-B(S * )-RL-D; (vi) Z’-A-B(S * )-RL-Y-D; (vii) Z’-A-D (viii) Z’-A-S*-W-D (ix) Z’-A-B(S*)-W-D (x) Z’-A-S*-W-RL-D; and (xi) Z’-A-B(S*)-W-RL-D

[0721] [In the formula, Z’ is a spacer unit precursor, A is a bond or connector unit, B is a parallel connector unit, S *is a dispenser, RL is a releasable linker, Y is a spacer unit, and D is a camptothecin compound selected from the group consisting of CPT1, CPT2, CPT3, CPT4, CPT5, CPT6, and CPT7 as follows: [Chemical formula] [Chemical formula]

[0722] (R B is a moiety selected from the group consisting of -H, C1-C8 alkyl, C1-C8 haloalkyl, C3-C8 cycloalkyl, (C3-C8 cycloalkyl)-C1-C4 alkyl-, phenyl, and phenyl-C1-C4 alkyl-; R C is a moiety selected from the group consisting of C1-C6 alkyl and C3-C6 cycloalkyl; R F and R F’ and R 10 are each independently a member selected from the group consisting of -H, C1-C8 alkyl, C1-C8 hydroxyalkyl, C1-C8 aminoalkyl, (C1-C4 alkylamino)-C1-C8 alkyl-, N,N-(C1-C4 hydroxyalkyl)(C1-C4 alkyl)-amino-C1-C8 alkyl-, N,N-di(C1-C4 alkyl)amino-C1-C8 alkyl-, N-C1-C4 hydroxyalkyl-C1-C8 aminoalkyl-, C1-C8 alkylC(O)-, C1-C8 hydroxyalkyl-C(O)-, C1-C8 aminoalkylC(O)-, C3-C 10 cycloalkyl, (C3-C 10 cycloalkyl)-C1-C4 alkyl-, C3-C 10 heterocycloalkyl, (C3-C F heterocycloalkyl)-C1-C4 alkyl-, phenyl, phenyl-C1-C4 alkyl-, diphenyl-C1-C4 alkyl-, heteroaryl, and heteroaryl-C1-C4 alkyl-; or R F’together with the nitrogen atom to which each of them is attached, form a 5-membered, 6-membered or 7-membered ring having 0 to 3 substituents selected from halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2, R B , R C , R F and R F’ The cycloalkyl, heterocycloalkyl, phenyl and heteroaryl moieties of are substituted by 0 to 3 substituents selected from the group consisting of halogen, C1-C4 alkyl, -OH, -OC1-C4 alkyl, -NH2, -NHC1-C4 alkyl and -N(C1-C4 alkyl)2) is

[0723] When the camptothecin-linker compound is of formula (i), formula (ii), formula (iii), formula (iv), formula (v) or formula (vi), the covalent attachment point of D is to any one of the heteroatoms of any one of the hydroxyl or amino substituents of CPT1-CPT7, or when the camptothecin-linker compound is of formula (vii), formula (viii) or formula (ix), or when the camptothecin-linker compound is of formula (iii), formula (iv), formula (x) or formula (xi) where RL is a releasable unit other than a glucuronide unit, the covalent attachment point of D is to the oxygen atom of the hydroxyl substituent on any one of the lactone rings of CPT1-CPT7,

[0724] provided that when the covalent attachment point is to the nitrogen atom of the amino substituent of CPT6, at least one of R F and R F’ is -H, provided that when D is CPT1 having a covalent bond through the nitrogen atom of its amino substituent, Z'-A- of the camptothecin-linker compounds of formula (i), formula (ii), formula (iii), formula (iv), formula (v) and formula (vi) is other than a maleimide-caproyl-β-alanyl moiety).

[0725] 18C. A is in units of connectors, and RL has the following structure in particular: [Chemical formula]

[0726] (wherein the wavy line marked with a single asterisk ( * ) indicates the site of covalent bond to D or the spacer unit (Y), and the wavy line marked with a double asterisk ( ** ) indicates the covalent bond point to A, B or S * )(The camptothecin-linker compound of Embodiment 17C having a glucuronide unit having and having a formula selected from the group consisting of formula (i), formula (ii); formula (iii), formula (iv), formula (v) and formula (vi).

[0727] 19C. The camptothecin-linker compound of Embodiment 18C, wherein the covalent bond point of D is via the oxygen atom of the hydroxyl substituent on any one of the lactone rings of CPT1 to CPT7.

[0728] 20C. D is CPT1, CPT4 or CPT6, the bonding point of CPT1 is via the nitrogen atom of its amine functional group, provided that Z'-A- is other than maleimide-caproyl-β-alanyl, the bonding point of CPT4 is for the nitrogen atom of its amine functional group, and the bonding point of CPT6 is via the nitrogen atom of its amine functional group, provided that at least one of F and F’ is -H, the camptothecin-linker compound of Embodiment 18C.

[0729] 21C. The camptothecin-linker compound of Embodiment 17C having formula (iii), formula (iv), formula (v) and formula (vi), wherein * is a PEG group.

[0730] 22C. D is any one of CPT1 to CPT7, and the spacer unit (Y) has the following formula: [Chemical formula]

[0731] (wherein EWG is an electron-withdrawing group, O * represents an oxygen atom derived from the hydroxy functional group of D, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to O * indicates the covalent bond site to the remainder of D), or D is R F and R F’ each of which is -H, selected from the group consisting of CPT1, CPT4 and CPT6, and the spacer unit (Y) has the following formula: [Chemical formula]

[0732] (wherein EWG is an electron-withdrawing group, the wavy line adjacent to the nitrogen atom indicates the covalent bond site to the carbonyl carbon atom of the glucuronide unit, and the wavy line adjacent to the carbonyl carbon atom indicates the covalent bond site to the nitrogen atom of the amine functional group of CPT1, CPT4 or CPT6 where each of R F and R F’ is -H), The camptothecin-linker compound of Embodiment 18C having Formula (ii), Formula (iv) or Formula (vi).

[0733] 23C. An alkynyl moiety-containing camptothecin-linker compound according to any one of Embodiments 17C to 22C, which is capable of undergoing a 1,3-dipolar cycloaddition with an azide substituent derived from a chemically modified targeting agent that is a precursor to the ligand unit of the camptothecin conjugate such that A results in a conjugate having a linker unit containing a triazolyl moiety.

[0734] 23C. Z'-A- contains a maleimide - alkanoyl moiety or mDPR, and its basic nitrogen atom is optionally protonated or protected by an acid - labile protecting group, provided that when D is CPT1 having a covalent bond through the nitrogen atom of its amino substituent, Z'-A- contains mDPR, and in particular, when D is CPT1, on the condition that D has a covalent bond to the oxygen atom of the hydroxyl substituent on its lactone ring, a camptothecin - linker compound of any one of Embodiments 17C - 22C, provided that Z'-A- contains mDPR or a maleimide - alkanoyl - β - alanine moiety.

[0735] 24C. A camptothecin - linker compound of Embodiment 17C having formula (vii), formula (viii) or formula (ix) in which A is a linker unit, or a camptothecin - linker compound of Embodiment 17C having formula (i), formula (iii), formula (x) or formula (xi) in which A is a linker unit and RL is a releasable linker other than a glucuronide unit.

[0736] 25C. RL has the following formula:

Chemical formula

[0737] (wherein the wavy line marked with a double asterisk ( ** ) indicates the covalent - bond site to D, and the wavy line marked with a single asterisk ( * ) indicates the covalent - bond point to A, S * or W), a camptothecin - linker compound of Embodiment 24C having formula (i), formula (iii) or formula (x).

[0738] 26C. A camptothecin - linker compound of Embodiment 25C having formula (x) in which W is an amino - acid unit selected from the group consisting of N - methyl - glycine (sarcosine), N - methyl - alanine, N - methyl - β - alanine, valine and N - methyl - valine.

[0739] 27C. A camptothecin-linker compound of Embodiment 24C, 25C or 26C, wherein Z'-A- comprises a maleimide-alkanoyl moiety or mDPR, and its basic nitrogen atom is optionally protonated or protected by an acid-labile protecting group.

[0740] 28C. Z'-A- is as follows:

Chemical formula

[0741] (wherein the wavy line marked with a double asterisk ( ** ) indicates the covalent bond site to S * ) A camptothecin-linker compound of Embodiment 24C, 25C or 26C having formula (iii) or formula (x), selected from the group consisting of the formulas:

[0742] 29C. S * has the following formula:

Chemical formula

[0743] (wherein the subscript n is an integer in the range of 2 to 36) A camptothecin-linker compound of Embodiment 24C, 25C or 26C having formula (iii) or formula (x).

[0744] 30C. Z'-A-S * -W- has the following formula:

Chemical formula

[0745] (wherein the subscript n is an integer in the range of 2 to 10, preferably in the range of 2 to 4, and the double asterisk ( **) The wavy line marked with () indicates the covalent bond site to D or RL) A camptothecin-linker compound of Embodiment 24C or 25C of Formula (viii) or Formula (x) having

[0746] 31C. The following structure:

Chemical formula

Chemical formula

Chemical formula

[0747] Or a camptothecin-linker compound of Embodiment 17C having its salt.

[0748] 32C. Use of a camptothecin conjugate in the preparation of a medicament for treating cancer in a subject, wherein the camptothecin conjugate has the formula of Embodiment 1C, particularly wherein the cancer is selected from the group consisting of lymphoma, leukemia and solid tumors, preferably lymphoma or leukemia.

[0749] 33C. A pharmaceutically acceptable composition comprising a camptothecin conjugate of Embodiment 1C and at least one pharmaceutically acceptable excipient.

[0750] 34C. A composition for treating cancer in a subject in need thereof, comprising an effective amount of a camptothecin conjugate of Embodiment 1C, particularly wherein the cancer is selected from the group consisting of lymphoma, leukemia and solid tumors, preferably lymphoma or leukemia.

[0751] 35C. A method for preparing the camptothecin conjugate of Embodiment 1, the method comprising contacting a targeting agent having a functional group reactive with Z' of the camptothecin-linker compound of claim 17, whereby a covalent bond is formed between the ligand unit and the stretcher unit (Z) of the camptothecin conjugate, respectively, structurally corresponding to the targeting agent and Z', in particular,

[0752] the targeting agent is an antibody having at least one cysteine residue in which the reactive functional group is a thiol, and Z' contains a maleimide moiety, or the targeting agent is an antibody modified to have an azide-containing residue as a reactive functional group, Z' contains an alkyne functional group, and the azide and alkyne functional groups are capable of undergoing a 1,3-dipolar cycloaddition to form a triazole ring system.

Example

[0753] Materials and Methods The following materials and methods can be applied to the synthetic procedures described in this section unless otherwise specified. All commercially available anhydrous solvents were used without further purification. Starting materials, reagents, and solvents were purchased from commercial suppliers (SigmaAldrich and Fischer). The products were obtained by flash column chromatography It was purified using the Biotage Isolera One (trademark) flash purification system (Charlotte, NC). UPLC-MS was performed using the UPLC method shown in Tables A - F with a Waters single quadrupole detector, which is a mass spectrometer interfaced with a Waters Acquity (trademark) UPLC system. Preparative HPLC was carried out with a Waters 2454 binary gradient module solvent delivery system configured with a Wasters 2998 PDA detector. The product was purified by elution with 0.05% trifluoroacetic acid in water and 0.05% trifluoroacetic acid in acetonitrile using a Phenomenex Max-RP 4μm Synergi (trademark) 80Å 250mm reverse-phase column of appropriate diameter, unless otherwise specified.

[0754]

Table 13

[0755]

Table 14

[0756]

Table 15

[0757]

Table 16

[0758]

Table 17

[0759]

Table 18

[0760]

Table 19

[0761] The camptothecin compounds provided in the following examples can be used in the preparation of the camptothecin-linker compounds and camptothecin conjugates described herein.

[0762] (Example 1) [Chemical formula]

[0763] SN-38 (Compound 1, 160.0 mg, 0.4077 mmol) purchased from MedChemExpress was suspended in anhydrous DCM (2 mL). After adding DIPEA (0.22 mL, 1.3 mmol), TBSCl (154 mg, 1.02 mmol) was added. The reaction mixture was stirred for 30 minutes until Compound 1 became soluble, and complete conversion was observed by UPLC-MS. The reaction was quenched with MeOH, filtered through a silica plug, and concentrated in vacuo. The resulting colorless oil was triturated with Hex. The product precipitated from the solution. The precipitate was collected by filtration, washed with Hex, and Compound 2 (TBS-SN-38) was obtained as a cloudy white solid (200 mg, 0.395 mmol, 97%). LC-MS (Method B): t R = 1.86 min; C 28 H 35 MS (m / z) of N2O5Si [M + H] + Calculated value 507.23, Measured value 506.96.

[0764] (Example 2) [Chemical formula]

[0765] Compound 3 was prepared according to the procedure described by Bioconjugate Chem. 2009, 20, 1242 - 1250 Therefore, it was synthesized. Compound 3 (50 mg, 0.108 mmol) was dissolved in DCM (1 mL). After adding DMAP (13 mg, 0.11 mmol) to the reaction, Boc2O (24 mg, 0.11 mmol) was added. The reaction was stirred for 5 minutes, at which point complete conversion to the desired product was observed. The protected product was purified by column chromatography on 10G Biotage Ultra with 0 - 5% MeOH in DCM. The fractions containing the desired product were concentrated in vacuo to give Compound 4 as a yellow solid (49 mg, 0.087 mmol, 80%). LC-MS (Method A): t R = 2.24 min; C 30 H 34 N3O8 MS (m / z) [M + H] + Calculated 564.23, found 564.10.

[0766] Compound 4 (49 mg, 0.087 mmol) was dissolved in anhydrous DCM (2 mL). DMAP (37 mg, 0.304 mmol) was added and the reaction was cooled to 0 °C. Triphosgene (12 mg, 0.039 mmol) dissolved in DCM at 10 mg / mL was added dropwise to the reaction over 15 minutes. A 2 μL aliquot was quenched in 98 μL of MeOH diluent and injected onto UPLC-MS. Complete conversion to the MeOH adduct was observed by UPLC-MS. The reaction mixture (Compound 5) can be used directly in the coupling step with the appropriate linker. LC-MS (Method A): t R = 2.09 min; C 32 H 36 N3O 10 MS (m / z) [M + H] + Calculated 622.24, found 622.02.

[0767] (Example 3)

Chemical Structure

[0768] Bioconjugate Chem. (2009) Compound 6 (150 mg, 0.334 mmol) synthesized according to the procedure described in 20: 1242-1250 was dissolved in anhydrous DCM (2 mL). DMAP (143 mg, 1.17 mmol) was added. Triphosgene (45 mg, 0.15 mmol) dissolved in anhydrous DCM (50 mg / mL) was added dropwise over 5 minutes. The reaction mixture was stirred at room temperature for 30 minutes. A 2 μL aliquot of the reaction mixture was quenched in 98 μL of MeOH diluent. Nearly complete conversion to the MeOH carbonate was observed, indicating the formation of the chloroformate. The thus-obtained compound 7 was used in the coupling step with the appropriate linker without further purification. LC-MS (Method A): t = 1.55 min; C R 27 H 27 N2O8 MS (m / z) [M+H] + Calculated 507.18, found 507.06.

[0769] (Example 4)

Chemical Structure

[0770] 6-Amino-3,4-(methylenedioxy)-acetophenone (8, 5.00 g, 27.9 mmol) obtained from TCI Research Chemicals (Catalog No. A1356) was dissolved in DCM (100 mL). The reaction was cooled to 0 °C, and after adding DIPEA (7.29 mL, 41.9 mmol), acetyl chloride (2.49 mL, 34.9 mL) was added slowly. The reaction was warmed 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 give compound 9 as a white solid, which was used in the next step without further purification. LC-MS (Method A): t = 1.37; C R 11 H 12 NO4 MS (m / z) [M+H] + Calculated 222.08, found 222.11. ​​

[0771] Compound 9 (27.9 mmol) was dissolved in AcOH (100 mL). 33% w / w HBr 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 mixture was stirred for 30 minutes, at which point conversion to the desired product was observed. The reaction mixture was poured onto ice water, and the precipitate was collected by filtration and washed with water. The filtrate was dried to give a yellow powder that was a mixture of the desired product, compound 10, and dibrominated products that were starting materials and impurities, which was used in the next step without further purification (7.2 g, 24 mmol, 86%). LC-MS (method A): t R = 1.58 min; C 11 H 11 MS (m / z) of C9H9BrNO4 [M + H] + Calculated 299.99, found 299.90.

[0772] Compound 10 (7.2 g, 24 mmol) was dissolved in EtOH (100 mL). Concentrated HBr (5 mL) was added, and the reaction mixture was heated to reflux for 60 minutes. Almost complete conversion to the deprotected product was observed. The reaction mixture was concentrated in vacuo and diluted with DCM (200 mL) and H2O (200 mL). The aqueous phase was extracted with DCM (3 × 200 mL), the collected organic phase was dried over MgSO4, filtered, and concentrated in vacuo. The crude product was purified by column chromatography with 0 - 10% MeOH in DCM. The fractions containing the desired product with a small amount of impurities were concentrated to give compound 11 as a yellow powder (4.05 g, 15.7 mmol, 65%). LC-MS (method A): t R = 1.57 min; MS (m / z) of C9H9BrNO3 [M + H] + Calculated 257.98, found 257.71.

[0773] (Example 5)

Chemical Structure

[0774] Compound 11 (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 placed in a flask. DCM (5 mL) was added to homogenize the solid, which was then evaporated under nitrogen. Next, the pure solid was heated at 120 °C under high vacuum (1 mbar) for 60 minutes. The reaction was cooled to room temperature, and the crude product was precipitated with H2O, filtered, and washed with H2O. The precipitate was purified by column chromatography with 0 - 10% MeOH in DCM. The fractions containing the desired product were concentrated in vacuo to give Compound 12 as a brown solid (989 mg, 2.04 mmol, 53%). LC-MS (Method A): t R = 1.62 min (General method UPLC); C 22 H 17 MS (m / z) of C + H

[0775] (Example 6)

Chemical Structure

[0776] Compound 12 (188 mg, 0.387 mmol) was dissolved in EtOH (5 mL). Hexamethylenetetramine (163 mg, 1.16 mmol) was added, and the reaction was stirred at reflux for 90 minutes. The reaction was cooled, and concentrated aqueous HCl (0.1 mL) was added. The reaction was concentrated and purified by preparative HPLC. The fractions containing the desired product were lyophilized to give Compound 13 as a cloudy white solid (109 mg, 0.259 mmol, 67%). LC-MS (Method A): t R = 0.89; C 22 H 20 MS (m / z) of C + H

[0777]

Table 20

[0778] The camptothecin compounds of Table H are exemplary compounds of the formula W-CPT, which are camptothecin conjugates of camptothecin having Q-D of the formula -Z-A-S * -W-D or -Z-A-B(S * )-W-D, or drug linker compounds of the formula Z’-A-S * -W-D or Z’-A-B(S * )-W-D, respectively, are incorporated via a covalent bond with an oxygen or nitrogen atom of a primary hydroxy or amine functional group.

[0779] (Example 7)

Chemical Structure

[0780] Compound 12 (10.0 mg, 20.6 μmol) from Example 4 was dissolved in anhydrous DMF (0.25 mL). Methylamine (2 M in THF, 0.031 mL, 62 μmol) was added. The reaction mixture was stirred for 30 minutes and then quenched with AcOH (20 μL). The reaction mixture was purified by preparative HPLC. The fractions containing the desired product (14) were lyophilized to give a yellow solid (3.27 mg, 7.51 μmol, 36%). LC-MS (Method D): t R = 1.57 min; MS (m / z) of C9H9BrNO3 [M+H] + Calculated 257.98, Found 257.71. t R = 0.93 min (Method A); C 23 H 22 N3O6 MS (m / z) [M+H] + Calculated 436.15, Found 435.78.

[0781]

Table 21-1

Table 21-2

[0782] Example 8 [ka]

[0783] Heterocycles, (2007) 71: 39-48), 6-nitro-1,3-benzodiamine Oxol-5-carbonitrile (compound 15, 2.00 g, 10.4 mmol) was prepared and then dissolved in EtOH (50 mL). The reaction was placed under a nitrogen atmosphere. Pd / C (2.22 g, 10% w / w, 2.08 mmol) was added to the reaction and it was placed under a hydrogen atmosphere. The reaction was stirred for 2 h. The reaction was filtered through a bed of Celite and then rinsed with MeOH. The eluent was concentrated in vacuo and purified by flash chromatography with 0-10% DCM in MeOH. The fractions containing the desired product were concentrated to give compound 16 as a red solid (1.46 g, 9.00 mmol, 87%). LC-MS (Method D):t R = 1.14 min; MS (m / z) of C8H7N2O2 [M+H] + Calculated value: 163.05, actual value: 162.37.

[0784] Example 9 [ka]

[0785] 6-Amino-1,3-benzodioxole-5-carbonitrile (Compound 16, 50 mg, 0.31 mmol) was placed under a nitrogen atmosphere and dissolved in anhydrous THF (1 mL). After adding CuBr (1.5 mg, 0.010 mmol), 1 M 4-fluorophenylmagnesium bromide in THF (1.23 mL) was added. The reaction mixture was heated at 60 °C for 30 minutes and then cooled to room temperature. 15% H2SO4 solution was slowly added to the reaction mixture, and then stirred for 30 minutes. The reaction mixture was poured into saturated NaHCO3 (50 mL), and then extracted with EtOAc (3 × 50 mL). The organic layer was dried over MgSO4, filtered, and concentrated in vacuo. The crude product was purified by column chromatography on a 10G Biotage Ultra with 0 - 10% EtOAc in hexanes. The fractions containing the desired product were concentrated in vacuo to give Compound 17 as a red solid (46.2 mg, 0.178 mmol, 58%). LC-MS (Method D): t R = 1.81 min; C 14 H 11 FNO3 MS (m / z) [M + H] + Calculated 260.07, Found 259.46.

[0786] (Example 10)

Chemical Structure

[0787] Compound 17 (46.2 mg, 0.178 mmol), p-TSA (30.7 mg, 0.178 mmol), and 4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (46.9 mg, 0.178 mmol, obtained from Avra Laboratories Pvt. Ltd.) were placed in a scintillation vial. DCM (1 mL) was added to homogenize the solid. The solvent was concentrated under nitrogen. The pure solid was heated at 120 °C for 60 minutes under high vacuum (1 mbar). The reaction was restored with DCM (50 mL), washed with H2O, the organic phase was washed and dried over MgSO4, filtered, and concentrated in vacuo. The crude product was purified by column chromatography on 10G Biotage Ultra with 0-10% MeOH in DCM. The fractions containing the desired product (18) were concentrated in vacuo to give a red solid (32.9 mg, 0.0676 mmol, 38%). LC-MS (Method D): t R = 1.81 min; C 27 H 20 MS (m / z) of C + H

[0788]

Table 22-1

Table 22-2

Table 22-3

Table 22-4

[0789] (Example 11)

Chem.

[0790] SN-38 (Compound 1, 76.0 mg, 0.19 mmol) obtained from MedChemExpress was dissolved in dichloromethane, and then triethylamine (128 μL, 0.92 mmol) and DMAP (2.60 mg, 0.02 mmol) were added. The mixture was cooled to 0 °C in an ice bath, and then acetyl chloride (15.9 μL, 0.22 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 16 h. The reaction was diluted with dichloromethane and washed with saturated NH4Cl, water, and brine. Next, the organic phase was dried over MgSO4, filtered, concentrated, and purified via Biotage flash column chromatography (CH2Cl2 / MeOH 0 - 15%) on silica to obtain acetylated SN-38 (19). MS (m / z) (M + H) + Calculated value 435.15, found value 435.07.

[0791]

Table 23-1

Table 23-2

[0792] (Example 12)

Chem.

[0793] Exatecan mesylate (compound 21a) 20.0 mg, 0.0376 mmol, obtained from MedChemExpress catalog number: HY-13631A) was suspended in anhydrous DCM (1 mL). DIPEA (20.0 μL, 0.0146 mmol) was added followed by acetoxyacetyl chloride (5.0 μL, 0.046 mmol). The reaction was stirred for 30 min, then quenched with MeOH and concentrated in vacuo. The reaction mixture was redissolved in MeOH (1 mL). LiOH (20 mg) was added. Complete deprotection of the acetate was observed. Quenched with AcOH. Purified by preparative HPLC 10 mm, 10-95% MeCN in H2O with 0.05% TFA. The fractions containing the desired product were concentrated in vacuo to give compound 21b as a yellow solid (15.3 mg, 0.0310 mmol, 82%). LC-MS (Method A): R =1.46 minutes;C 26 H 25 MS (m / z) of N3O6 [M+H] + Calculated value: 494.17, actual value: 494.05.

[0794] Example 13 [ka]

[0795] Exatecan mesylate (compound 21a, 20.0 mg, 0.0376 mol) was dissolved in MeCN (1 mL) and 0.75 M NaHCO3 in HO. Fmoc-OSu (19.0 mg, 0.0564 mmol) was added and the reaction was stirred for 2 h 30 min. The reaction was diluted with HO (50 mL), the pH was adjusted to neutral, and the reaction was washed with DCM (3 x 50 mL). The organic phase was dried over MgSO4, filtered and concentrated in vacuo. The crude product was purified by preparative TLC with 0-5% MeOH in DCM. The strip containing the desired product was scraped off, filtered, washed with 10% MeOH in DCM and the eluent was concentrated in vacuo to give compound 22 as an orange solid (19.1 mg, 0.0290 mmol, 77%). LC-MS (Method A):t R= 2.23 minutes; C 39 H 33 MS (m / z) of FN3O6 [M+H] + Calculated value 658.24, measured value 658.09.

[0796] (Example 14)

Chemical Structure

[0797] Compound 2 (132 mg, 0.260 mmol) prepared according to Example 1 was dissolved in 2 mL of anhydrous DCM. DMAP (111 mg, 0.911 mmol) was added. Triphosgene (34.8 mg, 0.117 mmol) was dissolved in anhydrous DCM at 50 mg / mL, and the solution was added dropwise to the stirred reaction solution over 5 minutes. A 2 μL aliquot of the reaction solution was quenched in 98 μL of MeOH diluent. After 15 minutes, almost complete conversion to the Me-carbonate was observed by UPLC-MS. The reaction mixture containing Compound 24 was used immediately in the coupling reaction described herein. Preparation of Camptothecin Drug-Linker Compounds

[0798] (Example 15)

Chemical Structure

[0799] Exatecan mesylate (Compound 21a, 5.00 mg, 9.41 μmol) was dissolved in anhydrous DCM. After adding DIPEA (5.0 μL, 28 μmol), Compound 25 (17.2 mg, 18.8 μmol) already described in Bioconjugate Chem. (2006) 17: 831-840 was added. The reaction was stirred at 40 °C for 3 hours. The reaction was quenched with MeOH and concentrated in vacuo. The crude reaction mixture was used in the next step. LC-MS (Method A): t and concentrated in vacuo. The crude reaction mixture was used in the next step. LC-MS (Method A): t R = 2.32 minutes; C 63 H 61 FN5O19 MS (m / z) [M+H] of + Calculated value: 1210.39, Measured value: 1210.08.

[0800] The crude compound 26 (9.41 μmol) from the previous step was dissolved in 1 M LiOH in THF (1 mL) and MeOH (1 mL). The reaction mixture was stirred for 5 minutes, then H2O was added and stirring was continued for another 5 minutes. The reaction mixture was quenched with AcOH (100 μL), concentrated in vacuo, and purified by preparative HPLC on a 21 mm column with 5 - 60 - 95% MeCN in H2O with 0.05% TFA. The fractions containing the desired product were lyophilized to give compound 27 as a yellow powder (1.1 mg, 1.3 μmol). LC-MS (Method A): t R = 1.29 min; C 41 H 43 FN5O 14 MS (m / z) [M+H] of + Calculated value: 848.28, Measured value: 848.03.

[0801] (Example 16)

Chemical Structure

[0802] Compound 27 (1.1 mg, 1.3 μmol) was dissolved in anhydrous DMF (0.5 mL). After adding DIPEA (1 μL), N-succinimidyl 3-maleimidopropionate (28, 0.63 mg, 2.4 μmol) purchased from TCI (CAS: 55750 - 62 - 4) was added. The reaction mixture was stirred for 5 minutes. Complete conversion was observed by UPLC-MS. The reaction mixture was quenched with AcOH (10 μL) and then purified by preparative HPLC on a 10 mm column with 5 - 60 - 95% MeCN in H2O with 0.05% TFA. The fractions containing the desired product were lyophilized to give compound 29 as a yellow powder (1.21 mg, 1.21 μmol, 93%). LC-MS (Method A): t R = 1.52 min; C 48 H 48 FN6O 17 MS (m / z) [M+H] of+ Calculated value: 999.31, measured value: 999.07.

[0803] (Example 17)

Chemical Structure

[0804] Compound 30 (210 mg, 0.234 mmol) prepared as described in Examples 21 and 22 was dissolved in bench DCM (3 mL). Paraformaldehyde (300 - 600 mg, xs) was added. While stirring vigorously, TMSBr ( 0.1 mL) was added. After stirring the reaction mixture for 10 minutes, complete conversion was observed by UPLC - MS at that point. The reaction mixture was filtered through a syringe filter, rinsed with DCM (2 × 3 mL), and toluene (3 mL) was added to azeotrope the final mixture. It was concentrated in vacuo to obtain a white solid. It was used in the next step without further purification. Using a MeOH diluent, an adduct quenched with MeOH was observed by UPLC - MS. LC - MS (Method A): t R = 2.19 minutes; C 44 H 51 N3NaO 18 MS (m / z) of C + H

[0805] (Example 18)

Chemical Structure

[0806] The compound 20c (20 mg, 0.047 mmol), called 7-BAD-MDCPT, was azeotroped three times with toluene and dried under high vacuum before use. The crude compound 31 (231 mg, 0.234 mmol) from Example 16 was dissolved in anhydrous DCM, and 1,2,2,6,6-pentamethylpiperidine (PMP, 51.4 μL, 0.284 mmol) was added. After adding the base, minimal hydrolysis of compound 31 in the solution was observed by UPLC-MS. The solution of compound 31 was added directly to the drug reaction vessel and then heate...

Claims

【Claim 1】 The invention described in this specification.

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