New drug complex

Abstract

The present invention provides a novel copolymer utilizable for drug delivery technology.　The present invention pertains to a drug complex in which a target recognition molecule is bound to a copolymer X comprising structural units represented by the following formulae (a), (b) and (c). [In the formulae, R1, R2, and R3 are the same or different and each represent a hydrogen atom or a C1-3 alkyl group; R4 represents a C1-3 alkyl group; R5 represents a hydrogen atom, a C1-18 alkyl group, an optionally substituted, 3- to 8-membered cycloalkyl group, an adamantyl group, an optionally substituted C6-18 aryl group, or an optionally substituted, 5- to 10-membered heteroaryl group; X1, X2, and X3 are the same or different and each represent an oxygen atom, a sulfur atom, or N-R7; R6 represents a hydrogen atom, a leaving group, or a linker; R7 represents a hydrogen atom or a C1-3 alkyl group; m is an integer of 1-100; and n is an integer of 0-3.]

Description

New drug conjugates

[0001] The present invention relates to a novel copolymer that can be used in drug delivery technology. More specifically, the present invention relates to a copolymer for use as a drug delivery carrier targeting tumors, a pharmaceutical composition in which the copolymer is loaded with a physiologically active substance such as an anticancer drug, and a pharmaceutical containing the composition.

[0002] In recent years, active research has been conducted on drug delivery systems (DDS) as a technology for efficiently and safely delivering drugs to disease sites. Among these, there is growing demand for DDS using nanoparticles as drug delivery carriers, as a technology that enhances drug accumulation selectivity by utilizing the structural characteristics of disease sites.

[0003] For example, in solid cancer tissue, the structure of newly formed blood vessels (tumor blood vessels) is immature compared to normal blood vessels, resulting in intercellular gaps of several hundred nanometers in the vascular endothelium, making them highly permeable to substances. Due to this structural feature, high molecular weight substances, including nanoparticles, are known to selectively penetrate tumor blood vessels and accumulate in solid cancer tissue. Furthermore, since the lymphatic system, which is responsible for the excretion of macromolecules, is dysfunctional in solid cancer tissue, the nanoparticles that penetrate the tissue are persistently retained within the tissue (enhanced permeability and retention effect, EPR effect). Conventional low-molecular-weight drugs leak out of blood vessels by permeating the membranes of vascular cells, so they are distributed nonselectively in tissues and do not accumulate in solid cancer tissue. According to the EPR effect methodology, drug delivery using nanoparticles improves tissue selectivity for solid cancers because tissue distribution is governed by the permeability of intercellular gaps in the vascular endothelium. Therefore, the EPR effect has become a powerful academic basis for the development of nanotechnology-based pharmaceuticals (nanomedicines) targeting solid cancers.

[0004] In the EPR effect, drug delivery is via the bloodstream, and the extravasation of nanoparticles is thought to be passive. Therefore, to maximize nanoparticle accumulation in solid tumors, it is important to design the nanoparticle components that serve as drug delivery carriers with molecular structures that can withstand long-term blood retention. Therefore, drug delivery carriers must be able to circumvent barriers such as nonspecific interactions with blood components, foreign body recognition by the reticuloendothelial system (RES) in the liver, spleen, and lungs, and glomerular filtration in the kidney. Furthermore, it is known that these barriers can be overcome by optimizing particle properties such as particle size and surface modification with biocompatible polymers. For example, the particle size of drug delivery carriers should be greater than approximately 6 nm, the threshold for renal clearance, and smaller than 200 nm, which allows them to escape RES recognition.

[0005] It is also known that the particle size of a drug delivery carrier affects tissue penetration at the disease site. For example, the anticancer activity of drug-loaded nanoparticles with particle sizes of 30 nm, 50 nm, 70 nm, and 100 nm, which show similar blood retention, has been compared, and it has been revealed that drug-loaded nanoparticles with a particle size of 30 nm exhibit the highest therapeutic effect because they reach the deepest parts of the disease site (Non-Patent Document 1). Therefore, it is considered desirable that the particle size of nanoparticles used as drug delivery carriers targeting solid cancers be as small as possible while avoiding renal clearance.

[0006] Nanoparticles for drug delivery carriers have been developed using methods that use colloidal dispersions such as liposomes, emulsions, or nanoparticles, methods that use biological materials such as albumin, methods that use natural polymers such as natural polysaccharides, and methods that use synthetic polymers. Among these, synthetic polymers are widely used as components of drug delivery carriers because they enable the preparation of nanoparticles with precisely controlled particle size by appropriately selecting the constituent monomers and synthesis methods.

[0007] For example, a method for using amphiphilic block copolymers consisting of hydrophilic and hydrophobic segments as drug delivery carriers has been disclosed. These block copolymers spontaneously associate in aqueous media, driven by intermolecular hydrophobic interactions and other factors, to form core-shell nanoparticles (polymeric micelles). The hydrophobic segments of these polymeric micelles can encapsulate or bind small molecule drugs. The resulting drug-encapsulated polymeric micelles are known to exhibit high blood stability and, due to their selective accumulation in solid tumors via the EPR effect, to exhibit greater anticancer activity than solutions of small molecule drugs (Patent Document 1). However, because polymeric micelles are aggregates of multiple molecules, the minimum particle size that can be prepared is approximately 30 nm, making it difficult to achieve a fine size control of the particle size to around 10 nm, which would avoid the effects of renal clearance.

[0008] On the other hand, among nanoparticles formed from synthetic polymers, those that form particles using chemical crosslinking within a single chain, hydrophobic interactions, ionic bonds, etc. as driving forces (hereinafter abbreviated as single chain nanoparticles (SCNPs)) are known to form small nanoparticles with a particle diameter of 20 nm or less (Non-Patent Document 2). Therefore, although SCNPs are expected to be useful as drug delivery carriers, no technology has been discovered to precisely control their particle diameter.

[0009] Another drug delivery technology is antibody-drug conjugates (ADCs), which enable targeted delivery of cytotoxic agents (drugs) to antigen-expressing tumor cells (Non-Patent Documents 3-5). ADCs contain three components: an antibody (Ab), a linker, and a drug. For localized delivery to the target, drugs are linked or conjugated to the antibody. Conjugation methods typically involve chemical modification via the amino groups of the antibody's lysine side chains or via cysteine ​​sulfhydryl groups obtained by reducing interchain disulfide bonds. Designing ADCs remains challenging, as multiple factors must be controlled, including antibody selection, linker stability, drug / toxin (payload) and its cleavage kinetics. One of the most important parameters is the number of payloads per single antibody (drug-antibody ratio or DAR). Antibodies conjugated with many drug / toxin molecules exhibit impaired binding to target antigens and rapid in vivo clearance from the bloodstream, and generally only a limited number of drug / toxin molecules can be conjugated to a single antibody (typically a DAR of 4-6). As a result, to achieve sufficient efficacy in killing target cells, highly toxic drugs (e.g., calicheamicin or auristatin monomethyl ester (MMAE)) with IC50 values ​​below 1 nM must be used (e.g., Non-Patent Documents 6 and 7). Therefore, even if only a small portion of the conjugate is delivered to an off-target site, serious adverse effects will occur. Thus, new approaches that combine high efficacy with improved tolerability are needed.

[0010] Patent No. 3270592

[0011] H. Cabral et al. , Nat. Nanotechnol. 6 815-823 (2011) Jose A. Pomposo, Single-Chain Polymer Nanoparticles: Synthesis, Characterization, Simulations, and Applications (2017) Chari, R. V. et al. , Angew. Chem. Int. Ed. 53, 3796-3827 (2014) Jagadeesh, D. , Smith, M. R. , Curr. Treat. Options Oncol. 17, 55 (2016) Ducry, L. , Stump, B. , Bioconjugate Chem. 21, 5-13 (2010) Casi, G. , Neri, D. , J. Controlled Release 161, 422-428 (2012) Wu, A. M. , Senter, P. D. , Nat. Biotechnol. 23, 1137-1146 (2005)

[0012] An object of the present invention is to provide a copolymer for a drug delivery carrier that targets tumors. More specifically, an object of the present invention is to provide a copolymer for a drug delivery carrier that can be used to improve blood retention and / or tumor accumulation of drugs.

[0013] In an extensive investigation to solve the above-mentioned problems, the present inventors discovered that a terpolymer of an acrylic acid derivative has the property of forming SCNPs in water. Furthermore, they succeeded in creating a copolymer for use as a drug delivery carrier that not only enables precise particle size control of SCNPs at a microscopic scale of approximately 10 nm to 20 nm, but also has high tumor accumulation. When a drug conjugate in which an anticancer drug was loaded or bound to the polymer was administered to a mouse model with subcutaneously implanted cancer, it exhibited excellent antitumor effects.

[0014] The present invention relates to the following inventions: [1] A copolymer in which a target recognition molecule is bound to a copolymer X having structural units represented by the following formulae (A), (B) and (C):

[0015]

[0016] [In the formula, R1 , R 2 and R 3 are the same or different and are hydrogen atoms or C 1-3 represents an alkyl group, and R 4 is C 1-3 represents an alkyl group, and R 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 represents an aryl group or an optionally substituted 5- to 10-membered heteroaryl group; X 1 , X 2 and X 3 are the same or different and are an oxygen atom, a sulfur atom, or an N-R 7 indicates R 6 represents a hydrogen atom, a leaving group or a linker, and R 7 is a hydrogen atom or C 1-3 [2] The copolymer X is represented by the following general formulas (1) to (3):

[0017]

[0018] [In the formula, R 1 , R 2 and R 3 are the same or different and are hydrogen atoms or C 1-3 represents an alkyl group, and R 4 is C 1-3 represents an alkyl group, and R 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 represents an aryl group or an optionally substituted 5- to 10-membered heteroaryl group; X 1 , X 2 and X 3 are the same or different and are an oxygen atom, a sulfur atom, or an N-R 7 indicates R 6 represents a hydrogen atom, a leaving group or a linker, and R 7 is a hydrogen atom or C 1-3[3] The copolymer according to [1] above, which is a copolymer formed by polymerization of three kinds of monomers represented by the formula: R 1 [4] The copolymer according to the above [1] or [2], wherein R is a hydrogen atom. 2 [5] The copolymer according to any one of [1] to [3] above, wherein R is a hydrogen atom. 3 [6] The copolymer according to any one of [1] to [4] above, wherein R is a hydrogen atom. 4 [7] The copolymer according to any one of [1] to [5], wherein R is a methyl group. 5 C which may have a substituent 6-18 [8] The copolymer according to any one of [1] to [6], wherein R is an aryl group. 5 [9] The copolymer according to any one of [1] to [7], wherein R is a phenyl group. 6

[10] The copolymer according to any one of [1] to [8], wherein R is a hydrogen atom. 6 is a leaving group of the following formula (4):

[0019]

[0020]

[11] The copolymer according to any one of [1] to [8] above, wherein R is a group represented by 6 The linker is represented by the following formula (5):

[0021]

[0022] [In the formula, R 8 represents a hydrogen atom or a drug, and Ak 1 is C 1-7 represents an alkylene bond, and X 4 is an oxygen atom, a sulfur atom, or —N(R 7 )-(R 7 is a hydrogen atom or C 1-3

[12] The copolymer according to any one of [1] to [8] above, wherein X is a group represented by the formula: 1

[13] The copolymer according to any one of [1] to

[11] above, wherein X is an oxygen atom. 2

[14] The copolymer according to any one of [1] to

[12] above, wherein X is an oxygen atom.3is an oxygen atom or NH.

[15] The copolymer according to any one of [1] to

[14] above, wherein m is an integer from 4 to 22.

[16] The copolymer according to any one of [1] to

[15] above, wherein n is 1.

[17] The copolymer according to any one of [1] to

[16] above, wherein the ratio of the structural units (A), (B), and (C) is 0.01 to 100 parts by mass of (B) and 0.1 to 100 parts by mass of (C) per part by mass of (A).

[18] The copolymer according to any one of [2] to

[16] above, obtained by polymerizing 0.01 to 100 parts by mass of monomer (2) and 0.1 to 100 parts by mass of monomer (3) per part by mass of monomer (1).

[19] The copolymer according to any one of [1] to

[18] above, wherein the number average molecular weight is 5,000 to 150,000.

[20] The copolymer according to any one of [1] to

[19] above, wherein the target recognition molecule is an antibody.

[21] The copolymer according to

[20] above, wherein the antibody is an anti-EGFR antibody, an anti-Her2 antibody, an anti-CD20 antibody, an anti-CD276 antibody, an anti-MUC1 antibody, an anti-PD-L1 antibody, or an anti-TROP-2 antibody.

[22] The copolymer according to

[20] above, wherein the antibody is cetuximab, panitumumab, necitumumab, amivantamab, panitumumab, trastuzumab, pertuzumab, margetuximab, rituximab, ibritumomab, tositumomab, ofatumumab, obinutuzumab, clivatuzumab, gatipotuzumab, ifinatamab, mirzotamab, vobramitamab, atezolizumab, avelumab, durvalumab, sacituzumab, or a functional fragment thereof.

[23] A drug conjugate comprising the copolymer according to any of [1] to

[22] above and a drug.

[24] The drug conjugate according to

[23] , wherein the drug is an antimetabolite, an alkylating agent, an anthracycline, an antibiotic, a mitotic inhibitor, a topoisomerase inhibitor, a proteasome inhibitor, or an antihormonal agent.

[25] The drug conjugate according to

[23] above, wherein the drug is DM0, DM1, DM2, DM3, DM4, emtansine, auristatin E, auristatin phenylalanine phenylenediamine (AFP), monomethyl auristatin E, monomethyl auristatin D, monomethyl auristatin F, paclitaxel, docetaxel, irinotecan, topotecan, nogitecan, amsacrine, etoposide, teniposide, mizanthrone, SN-38, exatecan, or deruxtecan.

[26] The drug conjugate according to any of

[23] to

[25] above, wherein the bond between the target recognition molecule or drug and the copolymer X is a covalent bond or a non-covalent bond.

[27] The bond between the target recognition molecule or drug and the copolymer X is represented by the following formula (a):

[0023]

[0024] [In the formula, J 1 is a target recognition molecule or a binding site for a drug, and J 2 is the bond to the copolymer X, and Ak 2 , Ak 3 are each independently a single bond or C 1-7 represents an alkylene bond, and B 1 , B 2 each independently represents a single bond, an amide bond, or an ester bond; L 1 is a single bond, -(CH2CH2O) o

[26] The drug conjugate according to any one of the above

[23] to

[26] , wherein o represents CH2CH2-, phenylene, cyclohexylene, -NH-peptide-CO-, or phenylene-NH-peptide-CO-, and o represents an integer of 0 to 100.

[27] A single chain nanoparticle comprising the copolymer or drug conjugate according to any one of the above [1] to

[26] .

[28] A single chain nanoparticle comprising the copolymer or drug conjugate according to any one of the above [1] to

[27] .

[29] A pharmaceutical composition comprising the copolymer or drug conjugate according to any one of the above [1] to

[26] .

[0025] As will be apparent from the examples described below, SCNPs obtained by self-association of the copolymer of the present invention, in which an anticancer drug is carried or bound, exhibited a tumor growth inhibitory effect in a mouse tumor-bearing model, and thus can be used as a therapeutic agent for malignant tumors. SCNPs obtained by self-association of the copolymer of the present invention, in which an anticancer drug is carried or bound, can achieve a higher DAR than existing ADCs and have a high tumor growth inhibitory effect at low doses, making it possible to provide a therapeutic agent for malignant tumors that can achieve both enhanced pharmacological action and suppressed side effects. Furthermore, the copolymers of the present invention bound to target recognition molecules are useful as drug delivery systems that utilize target-specific target recognition molecules.

[0026] FIG. 1 shows the results of measurements using nuclear magnetic resonance (NMR) for the copolymer obtained in Example 1. 1 Fig. 2 is a diagram showing a chromatogram obtained by gel permeation chromatography (GPC) for the copolymer obtained in Example 1. Fig. 3 is a diagram showing particle size measurement results (scattering intensity distribution) by dynamic light scattering (DLS) for the copolymer before DACHPt encapsulation (Example 69) and the DACHPt-encapsulated SCNP (Example 70). FIG. 4 shows the results of nuclear magnetic resonance (NMR) spectroscopy of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] obtained in Example 71. 15 is a chromatogram obtained by gel permeation chromatography (GPC) of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] obtained in Example 71. FIG. 6 shows the UV spectrum of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)]-isobutylonitrile obtained in Example 92, measured by UV spectroscopy (UV). FIG. 7 shows the UV spectrum of the DM1-cysteamine-linked copolymer obtained in Example 96, measured by nuclear magnetic resonance (NMR). 1 8 shows the H-NMR spectrum of the DM1-N-4-APM linked copolymer obtained in Example 108, measured by nuclear magnetic resonance (NMR). 1 9 shows the H-NMR spectrum of the 1,4-diaminobutane-linked copolymer obtained in Example 109, measured by nuclear magnetic resonance (NMR). 1 10 shows the H-NMR spectrum of the DM1-MHA-1,4-diaminobutane-linked copolymer obtained in Example 117, measured by nuclear magnetic resonance (NMR). 1 11 shows the H-NMR spectrum of the DM1-SPDP-1,4-diaminobutane-linked copolymer obtained in Example 118, measured by nuclear magnetic resonance (NMR). 112 shows the H-NMR spectrum of the DM1-SMCC-1,4-diaminobutane-linked copolymer obtained in Example 122, measured by nuclear magnetic resonance (NMR). 1 13 shows the H-NMR spectrum of the DM1-CL-031-1,4-diaminobutane-linked copolymer obtained in Example 124, measured by nuclear magnetic resonance (NMR). 1 14 shows the H-NMR spectrum of the DM1-CL-018-1,4-diaminobutane-linked copolymer obtained in Example 125, measured by nuclear magnetic resonance (NMR). 1 15 shows the H-NMR spectrum of the DM1-CL-038-1,4-diaminobutane-linked copolymer obtained in Example 126, measured by nuclear magnetic resonance (NMR). 1 16 shows the H-NMR spectrum of the DM1-CL-047-1,4-diaminobutane-linked copolymer obtained in Example 127, measured by nuclear magnetic resonance (NMR). 1 17 shows the H-NMR spectrum of the SN-38-CO-1,4-diaminobutane-linked copolymer obtained in Example 128, measured by nuclear magnetic resonance (NMR). 1 18 shows the H-NMR spectrum of the Deruxtecan-SPDP-1,4-diaminobutane-linked copolymer obtained in Example 129, measured by nuclear magnetic resonance (NMR). 119 shows the H-NMR spectrum of the 4-hydroxybutylamine-linked copolymer obtained in Example 130, measured by nuclear magnetic resonance (NMR). 1 20 shows the H-NMR spectrum of the Staurosporine (STS)-linked copolymer obtained in Example 131, measured by nuclear magnetic resonance (NMR). 1 21 shows the H-NMR spectrum of the Exatecan-PAB-Cit-Val-Ahx linked copolymer obtained in Example 158, measured by nuclear magnetic resonance (NMR). 1 2 shows H-NMR spectra. FIG. 22 shows the change in relative tumor volume when an oxaliplatin solution or DACHPt-encapsulated SCNP (Example 70) was administered three times every other day to a mouse model in which a mouse colon cancer cell line (C26) was subcutaneously implanted in the dorsal region. FIG. 23 shows the change in tumor volume when saline or a cetuximab-conjugated micelle-drug conjugate (Example 138) was administered to a mouse model in which a mouse EGFR-positive human colon cancer cell line HT-29 was subcutaneously implanted in the right flank. FIG. 24 shows the change in tumor volume when saline or a trastuzumab-conjugated micelle-drug conjugate (Example 151) was administered to a mouse model in which a mouse HER2-positive human gastric cancer cell line NCI-N87 was subcutaneously implanted in the right flank. Figure 25 is a graph showing changes in tumor volume when saline or cetuximab-conjugated micelle-drug conjugate (Example 160 or Example 161) is administered to model mice in which the mouse EGFR-positive human breast cancer cell line MDA-MB-468 was subcutaneously transplanted into the right flank. Figure 26 is a graph showing changes in tumor volume when saline or cetuximab-conjugated micelle-drug conjugate (Example 162 or Example 163) is administered to model mice in which the EGFR-positive human colon cancer cell line HCT-116 having a KRAS mutation (G13D) was subcutaneously transplanted into the right flank.

[0027] The terms used in this specification are used in the sense commonly used in the art unless otherwise specified. The present invention will be described in more detail below. In this specification, the term "nanoparticle" refers to a structure having a particle diameter of 100 nm or less.

[0028] As used herein, "single chain nanoparticle (SCNP)" refers to a nanoparticle formed using chemical crosslinking within a single chain, hydrophobic interactions, ionic bonds, or the like as a driving force. SCNPs often have a relatively small particle diameter of 20 nm or less, even among nanoparticles.

[0029] In this specification, the term "initiator" refers to an initiator of thermal radical polymerization such as an azo compound or a peroxide.

[0030] As used herein, the term "chain transfer agent" refers to a compound that causes a chain transfer reaction in radical polymerization, and is preferably a compound having a thiocarbonyl group.

[0031] As used herein, "C 1-3 The term "alkyl group" means a straight or branched chain alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.

[0032] As used herein, "C 1-18 The term "alkyl group" refers to a straight-chain or branched-chain alkyl group having 1 to 18 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group.

[0033] In the present specification, the term "optionally substituted 3- to 8-membered cycloalkyl group" refers to a cyclic alkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. The substituent is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, a dialkylamino group having 1 to 6 carbon atoms, the alkyl groups being the same or different, a thiol group, an alkylthio group having 1 to 6 carbon atoms, a carboxyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, and a carbamoyl group.

[0034] In the present specification, "C optionally having a substituent" 6-18 The term "aryl group" refers to a monocyclic or fused polycyclic aromatic hydrocarbon group, and examples thereof include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, and a naphthacenyl group. 6-14 The term "aryl group" refers to a monocyclic or fused-ring polycyclic aromatic hydrocarbon group, and examples thereof include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthrenyl group. The substituent is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, dialkylamino groups having 1 to 6 carbon atoms, the alkyl groups being the same or different, a thiol group, an alkylthio group having 1 to 6 carbon atoms, a carboxyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, and a carbamoyl group.

[0035] In this specification, the term "optionally substituted 5- to 10-membered heteroaryl group" refers to a 5- to 10-membered monocyclic aromatic heterocyclic group or fused aromatic heterocyclic group containing, as ring-constituting atoms other than carbon atoms, 1 to 4 heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms. Examples of the monocyclic aromatic heterocyclic group include a furyl group, a thienyl group, a pyrrolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an imidazolyl group, a pyrazyl group, a thialyl group, an oxazolyl group, an isoxazolyl group, a 1,3,4-thiadiazolyl group, a 1,2,3-triazolyl group, a 1,2,4-triazolyl group, and a tetrazolyl group. Examples of fused aromatic heterocyclic groups include benzofuranyl, benzothiophenyl, quinoxalinyl, indolyl, isoindolyl, isobenzofuranyl, chromanyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, quinolyl, and isoquinolinyl groups. Furthermore, the term "optionally substituted 6- to 10-membered heteroaryl group" refers to a 6- to 10-membered monocyclic aromatic heterocyclic group or a fused aromatic heterocyclic group containing, in addition to carbon atoms, 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur atoms as ring-constituting atoms. Examples of monocyclic aromatic heterocyclic groups include pyridinyl, pyrazinyl, pyrimidinyl, and pyridazinyl groups. Examples of the fused aromatic heterocyclic group include a benzofuranyl group, a benzothiophenyl group, a quinoxalinyl group, an indolyl group, an isoindolyl group, an isobenzofuranyl group, a chromanyl group, a benzimidazolyl group, a benzothiazolyl group, a benzoxazolyl group, a quinolyl group, an isoquinolinyl group, etc. The substituent is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, dialkylamino groups having 1 to 6 carbon atoms, the alkyl groups being the same or different, a thiol group, an alkylthio group having 1 to 6 carbon atoms, a carboxyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, a carbamoyl group, etc.

[0036] In this specification, examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0037] As used herein, "C 1-7The term "alkylene bond" means an optionally substituted, straight-chain or branched alkylene group having 1 to 7 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, -CH(CH3)-, -C(CH3)2-, -CH(CH2CH3)-, -CH(CH3)CH2-, -CH(CH2CH2CH3)-, -CH(CH2(CH3)2)-, -C(CH3)(CH2CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -CH(CH3)CH(CH3)-, -CH(CH3)CH2 CH2-, -CH2CH(CH3)CH2-, -CH(CH2CH2CH2CH3)-, -C(CH3)(CH2CH2CH3)-, - C(CH2CH3)2-, -CH(CH2CH2CH3)CH2-, -CH(CH2(CH3)2)CH2-, -C(CH3)(CH2C H3) CH2-, -C(CH3)2CH(CH3)-, -CH(CH2CH3)CH(CH3)-, -C(CH3)2CH2CH2-, - CH(CH2CH3)CH2CH2-, -CH2CH(CH2CH3)CH2-, -CH(CH3)CH(CH3)CH2-, -CH(C H3) CH2CH(CH3)-, -CH(CH2CH2CH2CH2CH3)-, -C(CH3)(CH2CH2CH2CH3)-, - C(CH2CH3)(CH2CH2CH3)-, -C(CH2CH3)(CH2(CH3)2)-, -CH(CH2CH2CH2CH3) CH2-, -CH(CH(CH3)CH2CH3)CH2-, -CH(CH2CH(CH3)CH3)CH2-, -CH(CH2CH2( CH3)2) CH2-, -C(CH3)(CH2CH2CH3)CH2-, -C(CH2CH3)2CH2-, -CH(CH2(CH3) 2) CH2-, -C(CH3)(CH2CH3)CH(CH3)-, -CH(CH2CH3)C(CH3)2-, -CH(CH2CH3) CH(CH2CH3)-, -C(CH3)2C(CH3)2-, -CH(CH2CH2CH3)CH2CH2-, -CH(CH2(CH3 )2) CH2CH2-, -CH2CH(CH2CH2CH3)CH2-, -CH2CH(CH2(CH3)2)CH2-, -C(CH3) (CH2CH3)CH2CH2-, -CH(CH2CH3)CH(CH3)CH2-, -CH(CH2CH3)CH2CH(CH3)-,-CH2CH(CH2CH3)-, -CH(CH3)CH(CH3)-, -C(CH3)2CH(CH3 )CH2-、-C(CH3)2CH2CH(CH3)-、-CH(C H2CH3)CH2CH2CH2-、-CH2CH(CH2CH3) CH2CH2-、-C(CH3)2CH2CH2CH2-、-CH( CH3)CH(CH3)CH2CH2-、-CH(CH3)CH2C H(CH3)CH2-、-CH(CH3)CH2CH2CH(CH3 )-、-CH(CH3)CH2CH2CH2CH2-、-CH2CH (CH3)CH2CH2CH2-、-CH2CH2CH(CH3) CH2CH2-、-C(CH2CH3)(CH2CH2CH2CH3 )-、-C(CH2CH2CH3)2-、-C(CH3)(CH2C H2CH2CH3)CH2-、-C(CH3)(CH(CH3)CH 2CH3)CH2-、-C(CH3)(CH2CH(CH3)CH3 )CH2-、-C(CH3)(CH2CH2(CH3)2)CH2- 、-CH(CH2CH2CH3)CH2CH3)CH2CH3)CH2CH3)CH2CH3)-, -CH(CH2C H(CH3)CH3(CH3)-, -CH(CH2CH2(CH3)-, -C(CH3)(CH2CH2CH 3) 3) 2) 3) 2) 3) 2) 3) 3) 2) 3) 3) 2) 3) 3) 2) 3) 3) 3) 2) 3) 3) 3) CH2CH3)C(CH3)2-、-C(CH3)(CH2CH2C H3)CH2CH2-、-CH(CH2CH2CH3)CH(CH3 )CH2-、-CH(CH2CH2CH3)CH2CH(CH3)- 、-CH2CH(CH2CH2CH3)CH(CH3)-、-C(C H3)(CH2CH3)CH(CH3)CH2-、-C(CH3)( CH2CH3)CH2CH(CH3)-、-CH(CH2CH3)C (3) 2) 2) , (2) 3) 2) 3) 3) 2) 3) 2) 3) 2) 3) 2) 3) 2) , ( ... C(CH3)(CH2CH3)(CH2CH3)(CH2CH3)(CH2-, -CH3)(CH2CH3)CH2-, -CH3)CH2CH3)CH2- 2CH3)CH(CH3)-, 2CH3(CH3)CH3)-, 2CH3(CH3)C(CH3)2CH(CH3)-,-C(CH3)2CH(CH3)CH2CH2-, -C(CH3)2CH2CH(CH3)CH2-, -C(CH3)2CH2CH2CH(CH3)-, -CH( CH3)C(CH3)2CH2CH2-, -CH(CH3)CH(CH3)CH(CH3)CH2-, -CH(CH3)CH(CH3)CH2CH(CH3)-, -CH(CH3)CH(CH3)CH2CH2CH2-, -CH(CH3)CH2CH(CH3)CH2CH2-, -CH(CH3)CH2CH2CH(CH3)CH2-, -C Examples include H(CH3)CH2CH2CH2CH(CH3)-, -C(CH3)2CH2CH2CH2CH2-, and -CH(CH2CH3)CH2CH2CH2CH2-. The substituent is not particularly limited, and any hydrogen atom can be substituted with the substituent, and examples thereof include a phenoxy group, a carboxylic acid, a sulfonic acid, a phosphoric acid, a hydroxyl group, and a thiol group.

[0038] As used herein, the term "target recognition molecule" refers to a molecule that recognizes and specifically binds to a marker or receptor (e.g., a transmembrane protein, a surface-insolubilized protein, or a proteoglycan) expressed on a cell surface. The molecule specifically recognizes a target that is specific to or overexpressed in cancer cells and is necessary for cancer growth and metastasis, and examples thereof include antibodies, lipocalins (e.g., anticalins), proteins (e.g., interferons, lymphokines, growth factors, colony-stimulating factors), peptides (e.g., LHRH receptor targeting peptides, EC-1 peptides), and peptidomimetics. In addition to having binding specificity, the target recognition molecule may also have a specific therapeutic effect, such as antiproliferative (cytostatic and / or cytotoxic) activity, against a target cell or pathway. The target recognition molecule may be supported on the copolymer X of the present invention by electrostatic interaction, hydrogen bonding, hydrophobic interaction, covalent bonding, or the like. It can be modified to the extent that binding specificity is maintained, and can be bound to the copolymer X via a chemically reactive group (carboxylic acid, primary amine, secondary amine, thiol, etc.), a chemically reactive amino acid residue or its side chain (tyrosine, histidine, cysteine, lysine, etc.). Hereinafter, the copolymer X of the present invention to which a target recognition molecule is bound or carried may be referred to as a "target-recognizing copolymer."

[0039] As used herein, the term "antibody" refers to a molecule or functional fragment thereof that has a sequence derived from an immunoglobulin such as IgG, IgM, IgA, IgD, or IgE and that has the characteristic of immunospecifically binding to a target antigen. This includes monoclonal antibodies, chimeric antibodies, recombinant antibodies, and humanized antibodies. Antigen-binding fragments that contain the idiotype may include the Fab region, F(ab')2 fragment, pFc' fragment, or Fab' fragment. The Fab region is composed of one constant domain and one variable domain derived from the heavy and light chains of an antibody. The Fc fragment and Fab fragment are fragments derived from immunoglobulins cleaved with the enzyme papain. The F(ab')2 fragment and pFc' fragment are fragments derived from immunoglobulins cleaved with the enzyme pepsin. The Fab' fragment is obtained by reducing the F(ab')2 fragment under mild conditions. In a further embodiment, the antibody can be used as an Fc fusion protein in which a functional protein such as a receptor extracellular domain is fused with the Fc domain of an immunoglobulin. It can also be used as a bispecific antibody capable of binding to two types of antigens or a multispecific antibody with an increased number of antigen-binding sites. Furthermore, chemical or biological modifications can be performed. When using recombinant DNA technology, it is sufficient to maintain the characteristics of the original amino acid sequence, and simultaneous or separate deletions, substitutions, insertions, or additions of one or more amino acids are permitted. For example, the amino acid sequence has a homology of 80% or more, preferably 90% or more, and more preferably 95% or more.

[0040] As used herein, the term "pharmaceutical composition" refers to a composition in which an active ingredient (drug, physiologically active substance) that can be used in the diagnosis, prevention, or treatment of a disease is carried on the copolymer X, target-recognition copolymer, or drug conjugate of the present invention by electrostatic interaction, hydrogen bonding, hydrophobic interaction, covalent bonding, or the like. When the copolymer X, target-recognition copolymer, or drug conjugate forms nanoparticles, examples of the carrying form include a form in which the drug is present on the particle surface, a form in which the drug is encapsulated within the nanoparticles, or a combination thereof.

[0041] One embodiment of the present invention is a copolymer or drug conjugate in which a target recognition molecule is bound to a copolymer X having structural units represented by the following formulae (A), (B) and (C).

[0042]

[0043] [In the formula, R 1 , R 2 and R 3 are the same or different and are hydrogen atoms or C 1-3 represents an alkyl group, and R 4 is C 1-3 represents an alkyl group, and R 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 represents an aryl group or an optionally substituted 5- to 10-membered heteroaryl group; X 1 , X 2 and X 3 are the same or different and are an oxygen atom, a sulfur atom, or an N-R 7 indicates R 6 represents a hydrogen atom, a leaving group or a linker, and R 7 is a hydrogen atom or C 1-3 represents an alkyl group, m represents an integer of 1 to 100, and n represents an integer of 0 to 3.

[0044] In the copolymer X of the present invention, the structural unit (A) functions as a unit that imparts hydrophilicity, and the structural unit (B) functions as a unit that imparts hydrophobicity. Furthermore, the structural unit (C) functions as a scaffold for binding an active ingredient (drug, physiologically active substance) to the copolymer X or the target-recognition copolymer. By virtue of having these three structural units, the copolymer X, target-recognition copolymer, or drug conjugate of the present invention has the property of forming SCNPs in water, and the formed SCNPs can be precisely controlled in particle size on a microscopic scale of 20 nm or less, functioning as a drug delivery carrier with high tumor accumulation.

[0045] R in the structural unit (A) 1 is a hydrogen atom or C 1-3X represents an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom. 1 is an oxygen atom, a sulfur atom, or N—R 7 m represents an integer of 1 to 100, preferably an integer of 3 to 100, and from the viewpoint of imparting good hydrophilicity, preferably an integer of 3 to 80, more preferably an integer of 4 to 60, even more preferably an integer of 4 to 40, and even more preferably an integer of 4 to 22. 4 is C 1-3 It represents an alkyl group, specifically a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0046] R in the structural unit (B) 2 is a hydrogen atom or C 1-3 X represents an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom. 2 is an oxygen atom, a sulfur atom, or N—R 7 Although n represents an integer of 0 to 3, an integer of 1 to 3 is preferred, and 1 is more preferred. 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 It represents an aryl group or a 5- to 10-membered heteroaryl group which may have a substituent, but from the viewpoint of imparting hydrophobicity to the structural unit (B), C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 An aryl group or an optionally substituted 5- to 10-membered heteroaryl group is preferred, and C 1-18 an alkyl group, an optionally substituted 3- to 8-membered cycloalkyl group, an adamantyl group, an optionally substituted C 6-18 An aryl group or an optionally substituted 5- to 10-membered heteroaryl group is more preferred, and C 1-18an alkyl group, a 3- to 8-membered cycloalkyl group, an adamantyl group, or C 6-18 An aryl group is even more preferred. On the other hand, an optionally substituted 3- to 8-membered cycloalkyl group, an adamantyl group, an optionally substituted C 6-14 An aryl group or a 6- to 10-membered heteroaryl group which may have a substituent is also preferred. Here, the substituent is preferably one or more selected from a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkynyl group having 2 to 6 carbon atoms.

[0047] R in the structural unit (C) 3 is a hydrogen atom or C 1-3 X represents an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom. 3 is an oxygen atom, a sulfur atom, or N—R 7 R is preferably an oxygen atom, a sulfur atom or NH, and more preferably an oxygen atom or NH. 6 represents a hydrogen atom, a leaving group, or a linker. The leaving group is a group that can be removed when the structural unit (C) binds to a drug (biologically active substance), and the linker is a group that can be used for crosslinking when the structural unit (C) binds to a drug (biologically active substance). These leaving groups or linkers include C which may have a substituent. 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, a C 7-19 An aralkyl group is preferred. Examples of the substituent include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, dialkylamino groups having 1 to 6 carbon atoms, the alkyl groups being the same or different, a thiol group, an alkylthio group having 1 to 6 carbon atoms, a carboxyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, and a carbamoyl group. Of these groups, as the linker, a group having a functional group such as a hydroxyl group, an amino group, a thiol group, or a carboxyl group as a substituent is preferred. R 6 Preferred specific examples of the leaving group include those of the following formula (4):

[0048]

[0049] Examples of the group include a group represented by the following formula: 6 A preferred specific example of the linker is the linker of the following formula (5):

[0050]

[0051] [In the formula, R 8 represents a hydrogen atom or a drug, and Ak 1 is C 1-7 represents an alkylene bond, and X 4 is an oxygen atom, a sulfur atom, or —N(R 7 )-(R 7 is a hydrogen atom or C 1-3 In the formula (5), X represents an alkyl group. 4 However, those representing an oxygen atom, a sulfur atom or NH are more preferred.

[0052] The copolymer X of the present invention is a copolymer having structural units represented by formulae (A), (B), and (C). The copolymer X may be a random copolymer or a block copolymer, but is preferably a random copolymer. The compositional ratio of each structural unit in one molecule is preferably such that, relative to 1 part by mass of (A), (B) is 0.01 to 100 parts by mass and (C) is 0.1 to 100 parts by mass; more preferably, relative to 1 part by mass of (A), (B) is 0.05 to 18 parts by mass and (C) is 0.1 to 20 parts by mass; and particularly preferably, relative to 1 part by mass of (A), (B) is 0.05 to 4 parts by mass and (C) is 0.1 to 16 parts by mass.

[0053] The degree of polymerization of the copolymer X of the present invention is not particularly limited, but the number average molecular weight is preferably 5,000 to 150,000, more preferably 8,000 to 150,000.

[0054] In the copolymer of the present invention, as described above, the monomer represented by general formula (1) functions as a unit imparting hydrophilicity, and the monomer represented by general formula (2) functions as a unit imparting hydrophobicity. Furthermore, the monomer represented by general formula (3) functions as a scaffold for binding the drug to the copolymer. Examples of monomers that function as the hydrophobic unit represented by general formula (2) include those represented by the following formula:

[0055]

[0056]

[0057]

[0058] Examples of the monomer include the monomer represented by the following formula:

[0059] In general formula (1), R 1 is a hydrogen atom or C 1-3 The alkyl group is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom.

[0060] In general formula (2), R 2 is a hydrogen atom or C 1-3 The alkyl group is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom.

[0061] In general formula (3), R 3 is a hydrogen atom or C 1-3 The alkyl group is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, an ethyl group or a propyl group, and more preferably a hydrogen atom.

[0062] In general formula (1), R 4 is C 1-3 It represents an alkyl group, specifically a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0063] In general formula (1), X 1 is an oxygen atom, a sulfur atom, or N—R 7 Although it is preferably an oxygen atom, a sulfur atom or NH, an oxygen atom is more preferred.

[0064] In general formula (1), m represents an integer of 1 to 100, preferably an integer of 3 to 100, and from the viewpoint of imparting good hydrophilicity, preferably an integer of 3 to 80, more preferably an integer of 4 to 60, even more preferably an integer of 4 to 40, and still more preferably an integer of 4 to 22.

[0065] In general formula (2), R 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 It represents an aryl group or a 5- to 10-membered heteroaryl group which may have a substituent, but from the viewpoint of imparting hydrophobicity to the structural unit (B), C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 An aryl group or an optionally substituted 5- to 10-membered heteroaryl group is preferred, and C 1-18 an alkyl group, an optionally substituted 3- to 8-membered cycloalkyl group, an adamantyl group, an optionally substituted C 6-18 An aryl group or an optionally substituted 5- to 10-membered heteroaryl group is more preferred, and C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group, an adamantyl group, or C 6-18 An aryl group is more preferred. On the other hand, an optionally substituted 3- to 8-membered cycloalkyl group, an adamantyl group, an optionally substituted C 6-14 An aryl group or a 6- to 10-membered heteroaryl group which may have a substituent is also preferred. Here, the substituent is preferably one or more selected from a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkynyl group having 2 to 6 carbon atoms.

[0066] In general formula (2), X 2 is an oxygen atom, a sulfur atom, or N—R 7 Although it is preferably an oxygen atom, a sulfur atom or NH, an oxygen atom is more preferred.

[0067] In the general formula (2), n represents an integer of 0 to 3, preferably an integer of 1 to 3, and more preferably 1.

[0068] In general formula (3), R6 represents a hydrogen atom, a leaving group, or a linker. These leaving groups or linkers include C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, a C 7-19 An aralkyl group is preferred. Examples of the substituent include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, dialkylamino groups having 1 to 6 carbon atoms, the alkyl groups being the same or different, a thiol group, an alkylthio group having 1 to 6 carbon atoms, a carboxyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, and a carbamoyl group. Of these groups, as the linker, a group having a functional group such as a hydroxyl group, an amino group, a thiol group, or a carboxyl group as a substituent is preferred. R 6 Preferred specific examples of the leaving group include those of the following formula (4):

[0069]

[0070] Examples of the group include a group represented by the following formula: 6 A preferred specific example of the linker is the linker of the following formula (5):

[0071]

[0072] [In the formula, R 8 represents a hydrogen atom or a drug, and Ak 1 is C 1-7 represents an alkylene bond, and X 4 is an oxygen atom, a sulfur atom, or —N(R 7 )-(R 7 is a hydrogen atom or C 1-3 In formula (5), X represents an alkyl group. 4 However, those representing an oxygen atom, a sulfur atom or NH are more preferred.

[0073] In general formula (3), X 3 is an oxygen atom, a sulfur atom, or N—R 7 Although it represents the above, an oxygen atom, a sulfur atom or NH is preferable, and an oxygen atom or NH is more preferable.

[0074] The copolymer X of the present invention is formed by copolymerizing three types of monomers represented by general formulas (1) to (3). The copolymerization may be random copolymerization or block copolymerization, but random copolymerization is preferred. The blending ratio of the three types of monomers is preferably 0.01 to 100 parts by mass of monomer (2) and 0.1 to 100 parts by mass of monomer (3), more preferably 0.05 to 18 parts by mass of monomer (2) and 0.1 to 20 parts by mass of monomer (3), and particularly preferably 0.05 to 4 parts by mass of monomer (2) and 0.1 to 16 parts by mass of monomer (3), where 1 part by mass of monomer (1) is taken as 1.

[0075] Furthermore, "solvates" in which various solvents are coordinated are also encompassed by the copolymer X of the present invention. In this specification, "solvates" include, for example, hydrates and ethanol solvates. The number of solvents coordinated to the copolymer X of the present invention may be any number.

[0076] The copolymer X of the present invention can be produced by various known methods. The production method is not particularly limited, but it can be produced, for example, according to the basic polymer synthesis method described below.

[0077]

[0078] wherein R′ is a hydrogen atom or C 1-3 R" represents an alkyl group, 4 , R 5 or R 6 represents a group represented by the following formula:

[0079] This reaction represents a step of producing a polymer (III) by reacting a monomer (I) with a chain transfer agent (II) and an initiator. This reaction can be carried out without a solvent or in a solvent such as an alcohol such as methanol, ethanol, 1-propanol, or 2-propanol; an ether such as diethyl ether, tetrahydrofuran, or 1,4-dioxane; an aromatic hydrocarbon such as benzene, toluene, or xylene; a halogenated hydrocarbon such as dichloromethane, chloroform, or 1,2-dichloroethane; N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, or ethyl acetate. It is preferable to use an aromatic hydrocarbon such as toluene or xylene as the solvent. As a chain transfer agent, 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT), Cyanomethyl dodecyltrithiocarbonate (CDTTC), 2-Cyano-2-propyldodecyl trithiocarbonate (CPDTTC), 4-Cyano-4-[(dodecylsulfanyl-thiocarbonyl)sulfanyl]pentanoic acid (CDSPA), 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 3-azido-1-propanol ester (N3-CTA), N3-PEG mEster-CTA (m is the same as above), for example, 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 2-(2-(2-azidoethoxy)ethoxy)ethyl ester (N3-PEG2Ester-CTA), 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 17-azido-3,6,9,12,15-pentaoxaheptadecan-1-ol ester (N3-PEG5Ester-CTA), 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 23-azido-3,6,9,12,15,18,21-heptaoxatricosan-1-ol ester (N3-PEG7Ester-CTA), N3-PEG mAmide-CTA (m is the same as above), for example, N-(8-Azido-3,6-dioxaoctan-1-yl)-2-(dodecylthiocarbonothioylthio)-2-methylpropanamide (N3-PEG2Amide-CTA), N-(17-Azido-3,6,9,12,15-pentaoxaheptadecan-1-yl)-2-(dodecylthiocarbonothioylthio)-2 Examples of the copolymer X that can be used include N-(23-Azido-3,6,9,12,15,18,21-heptaoxatricosan-1-yl)-2-(dodecylthiocarbonothioylthio)-2-methylpropanamide (N-PEG7Amide-CTA), and the like. DDMAT or N-CTA is preferably used, and N-CTA is more preferred. When polymerization is carried out using a chain transfer agent, the copolymer X of the present invention has a structure in which part or all of the structure of the chain transfer agent is partially bonded. When copolymer X contains the structure of the chain transfer agent, the structure may be removed by an appropriate method. As the initiator, an azo-based polymerization initiator such as 2,2'-azobis-isobutylonitrile (AIBN), 1,1'-azobis(cyclohexanecarbonitrile) (ACHN), 2,2'-azobis-2-methylbutylonitrile (AMBN), 2,2'-azobis-2,4-dimethylvaleronitrile (ADVN), or dimethyl 2,2'-azobis(2-methylpropionate) (MAIB) can be used, and it is preferable to use AIBN. The reaction temperature is 0 to 300°C, preferably 0 to 150°C, more preferably 1 to 100°C, and the reaction time is 1 minute to 48 hours, preferably 5 minutes to 24 hours. In this reaction, by carrying out the reaction in the coexistence of monomers (I) having different structures, a randomly copolymerized copolymer X can be produced.For example, if N3-CTA having an azide group is used as a chain transfer agent, a copolymer X having an azide group at the end can be obtained, which is advantageous for producing a target-recognizing copolymer by the click reaction described below.

[0080] The target recognition molecule that binds to the copolymer X is preferably an antibody that recognizes a marker or receptor expressed on a cell surface, a mutant (modified) thereof, or a functional fragment (antibody fragment) thereof, and specific examples thereof include BCMA, BLyS, CA-125, CCR4, CD3, CD19, CD20, CD22, CD25, CD30, CD33, CD38, CD40L, CD52, CD74, CD79b, CEACAM5, CEACAM6, CSAp, CTLA-4, CXCR4, EGFR, EpCAM, ErbB2 (HER2), GD2, gp100, HLA-DR, IGF-1R, IL-6R, cMET, MUC1, Nectin-4, PD-1, PD-L1, PDGFR, SLAMF7, PSMA, TAG-72, TF, TNF-α, TROP-2 (EGP-1), VEGF, VEGFR1, VEGFR2, α4 integrin, α-fetoprotein (AFP), fibrin, CAIX, A33, B7, CA125, CCL19, CD2, CD4, C D8, CD11A, CD14, CD15, CD16, CD18, CD23, CD32b, CD37, CD40, CD44, CD45, CD54, CD55, CD59, CD64, CD66, CD70, CD80, CD95, CD138, CD147, CD154, CD276, EGFRvIII, FGF, Flt-1, FRα, HMGB-1, IL-4R, IL-12, IL-15, IGF-1, IGF-2, MIF, TRAG-3, MCP-1, CD67, CD70L, Examples of such antibodies include antibodies or mutant (modified) or functional fragments thereof that target one or more of CD79a, CD132, CD133, CDC27, CDK-4 / m, CDKN2A, CXCR7, CXCL12, HIF-1α, EGP-2, ILGF-1R, SAGE, S100, survivin, survivin-2B, TAC, tenascin, TRAIL-R, Tn antigen, Thomsen-Friedenreich antigen, WT-1, bcl-2, bcl-6, or Kras. Among these, preferred targets include antibodies or mutant (modified) or functional fragments thereof that target one or more selected from the group consisting of CD20, CD276, MUC1, EGFR, HER2, PD-L1, and TROP-2.

[0081] Preferred individual antibodies include, for example, alemtuzumab (anti-CD52), bevacizumab (anti-VEGF), ramucirumab (anti-VEGFR2), cetuximab (anti-EGFR), gemtuzumab (anti-CD33), panitumumab (anti-EGFR), necitumumab (anti-EGFR), amivantamab (anti-EGFR / cMET), rituximab (anti-CD20), ibritumomab (anti-CD20), tositumomab (anti-CD20), ofatumumab (anti-CD20), and mosunetuzumab (anti-CD20 / CD3). , trastuzumab (anti-ErbB2), pertuzumab (anti-HER2), margetuximab (anti-HER2), patritumab (anti-HER3), lambrolizumab (anti-PD-1), nivolumab (anti-PD-1), pembrolizumab (anti-PD-1), cemiplimab (anti-PD-1), dostarimab (anti-PD-1), toripalimab (anti-PD-1), atezolizumab (anti-PD-L1), avelumab (anti-PD-L1), durvalumab (anti-PD-L1), ipilimumab (anti-CTLA-4), avelumab (anti-PD-L1), (anti-CA-125), adecatumumab (anti-EpCAM), belantamab (anti-BCMA), mogamulizumab (anti-CCR4), catumacimab (anti-CD3 / EpCAM), edrecolomab (anti-EpCAM), blinatumomab (anti-CD19 / CD3), tafasitamab (anti-CD19), roncastaximab (anti-CD19), inotuzumab (anti-CD22), moxetumomab (anti-CD22), brentuximab (anti-CD30), polatuzumab (anti-CD79b), dinutuximab (anti-GD2) , naccitamab (anti-GD2), tebentafusp (anti-gp100 / CD3), enfortumab (anti-Nectin-4), olaratumab (anti-PDGFR), elotuzumab (anti-SLAMF7), tisotumab (anti-TF), sacituzumab (anti-TROP-2), tocilizumab (also known as atlizumab: anti-IL-6 receptor), obinutuzumab (also known as GA101: anti-CD20), CC49 (anti-TAG-72), AB-PG1-XG1-026 (anti-PSMA, U.S. Pat. No. 8,114,965, ATCC PTA-4405 and PTA-4406), D2 / B (anti-PSMA, WO 2009 / 130575), daclizumab (anti-CD25), muromonab-CD3 (anti-CD3), natalizumab (anti-α4 integrin), infliximab (anti-TNF-α),Certolizumab pegol (anti-TNF-α), adalimumab (anti-TNF-α), dapirolizumab pegol (anti-CD40L), letolizumab (anti-CD40L), ruplizumab (anti-CD40L), belimumab (anti-BLyS), 59D8 (anti-fibrin), biciromab (also known as T2G1s: anti-fibrin), MH1 (anti-fibrin), felzalutamab (anti-CD38), isatuximab (anti-CD38), daratumumab (anti-CD38), hR1 (anti-IGF-1R, U.S. Publication No. 2010 / 226,884), clivatuzumab (anti-MUC1), gatipotuzumab (anti-MUC1 ), veltuzumab (also known as hA20: anti-CD20, U.S. Pat. No. 7,151,164), hA19 (anti-CD19, U.S. Pat. No. 7,109,304), hIMMU31 (anti-AFP, U.S. Pat. No. 7,300,655), milatuzumab (also known as hLL1 (anti-CD74, U.S. Pat. No. 7,312,318), epratuzumab (also known as hLL2: anti-CD22, U.S. Pat. No. 7,074,403), hMu-9 (anti-CSAp, U.S. Pat. No. 7,387,773), hL243 (anti-HLA-DR, U.S. Pat. No. 7,612,180), labetuzumab (also known as hMN-14: anti-CEACAM5, US Patent No. 6,676,924), hMN-3 and hMN-15 (anti-CEACAM6, US Patent No. 7,541,440), Ab124 and Ab125 (anti-CXCR4, US Patent No. 7,138,496), G250 (anti-CAIX), A33 (anti-A33), Galiximab (anti-B7), OC125 (anti-CA125), avagovomab (anti-CA125), CAP-100 (anti-CCL19), TRX-3 (anti-CD2), IT-1208 (anti-CD4), zanolimumab (anti-CD4), cefmilimab (anti-CD8), afelimomab (anti-CD11A) ), Cytolin (anti-CD11A), efalizumab (anti-CD11A), odulimomab (anti-CD11A), ativclimab (anti-CD14), fanolesomab (anti-CD15), GTB-4550 (anti-CD16), erelumab (anti-CD18), odulimomab (anti-CD18), rovelizumab (anti-CD18), lumiliximab (anti-CD23), obexelimab (anti-CD32b), BI-1206 (anti-CD32b), HuMax-CD32b (anti-CD32b), NVS-32b (anti-CD32b), NNV-003 (anti-CD37), rilotomab (anti-CD37),K7153A (anti-CD37), iscalimab (anti-CD40), ChiLob7 / 4 (anti-CD40), CDX-1140 (anti-CD40), TNX-1500 (anti-CD40L), TES-23 (anti-CD44), bivatuzumab (anti-CD44), actimab-B (anti-CD45), BI -505 (anti-CD54), enrimomab (anti-CD54), MOR-101 (anti-CD54), MOR-102 (anti-CD54), Onivax -105 (anti-CD55), GB-262 (anti-CD55), PAT-SC1 (anti-CD55), VG-102 (anti-CD55), AR36A36 11.1 (anti-CD59), KNP-302 (anti-CD59), MDX-210 (anti-CD64), MDX-220 (anti-CD64), tinurilimab (anti-CD66c), cusatuzumab (anti-CD70), MDX-1411 (anti-CD70), cosibelimab (anti-PD-L1), galiximab (anti-CD80), Novotarg (anti-CD95), DOM-1112 (anti-CD138), indatuximab (anti-CD138), gavilimomab (anti-CD147), letolizumab (anti-CD154), ABI-793 (anti-CD154), DOM-0800 (anti-CD154), Ifinatatama (anti-CD276), mirzotamab (anti-CD276), vobramitamab (anti-CD276), AMG-596 (anti-EGFRvIII), bemarituzumab (anti-FGF), burosumab (anti-FGF), U3-1784 (anti-FGF), apultuzumab (anti-FGF), icrucumab (anti-Flt-1 / VEGFR), faretuzumab (anti-FRα), mirvetuximab (anti-FRα), girentuximab (anti-CAIX), MEDI-541 (anti-HMGB-1), dupilumab (anti-IL-4R), revilimab (anti-IL-6R), SANT-7 (anti-IL-6R), bovalizumab Mab (anti-IL-6R), sarilumab (anti-IL-6R), clazakizumab (anti-IL-6R), TZLS-501 (anti-IL-6R), ustekinumab (anti-IL-12), briakinumab (anti-IL-12), oldesekimab (anti-IL-15), cixutumumab (anti-IGF-1), figitumumab (anti-IGF-1), teprotumumab (anti-IGF-1), dalotuzumab (anti-IGF-1), gantumab (anti-IGF-1), lobatumab (anti-IGF-1), AVE1642 (anti-IGF-1), dusitumab (anti-IGF-1 / 2), istirab (anti-IGF-1),Examples include xentuzumab (anti-IGF-1), imalumab (anti-MIF), leratolimab (anti-TRAG-3), carbamazepine (anti-MCP-1), alacizumab pegol (anti-VEGFR-2), brolucizumab (anti-VEGFR), gentuximab (anti-VEGFR), and olinbasimab (anti-VEGFR-2).

[0082] The linker to be bound to the copolymer X may be any linker capable of linking (interacting) the copolymer X with a drug or a target recognition molecule, and may be an amino acid residue, a bifunctional derivative, a bond utilizing a bioorthogonal reaction, an alkylene bond, a polyethylene glycol (PEG) bond, a disulfide bond, or a thioether bond.

[0083] Examples of linkers having a protease cleavage site (e.g., a cathepsin B cleavage site, a cathepsin C cleavage site, or a cathepsin D cleavage site) include peptides whose amino acid residues consist of alanine, phenylalanine, glycine, valine, lysine, citrulline, serine, glutamic acid, aspartic acid, etc. For example, they include dipeptides, tripeptides, tetrapeptides, and pentapeptides, and may be naturally occurring or non-naturally occurring amino acid residues. Examples of such amino acids include valine-citrulline (ve or val-cit), valine-alanine (va or val-ala), valine-lysine (val-lys), phenylalanine-alanine (phe-ala), phenylalanine-lysine (fk or phe-lys), phenylalanine-citrulline (phe-cit), phenylalanine-phenylalanine-lysine (phe-phe-lys), alanine-phenylalanine (af or ala-phe), alanine-lysine (ala-lys), glycine-glycine (gly-gly), glycine-alanine-phenylalanine (gly-ala-phe), Examples include glycine-valine-citrulline (gly-val-cit), glycine-glycine-glycine (gly-gly-gly), glycine-phenylalanine-lysine (gly-phe-lys), glycine-phenylalanine-leucine-glycine (gly-phe-leu-gly), glycine-glycine-phenylalanine-glycine (gly-gly-phe-gly), leucine-citrulline (leu-cit), isoleucine-citrulline (ile-cit), tryptophan-citrulline (trp-cit), and alanine-leucine-alanine-leucine (ala-leu-ala-leu).

[0084] Furthermore, examples of linkers that form a carbamate group / carbonate group or the like with a drug or antibody via peptide-p-aminobenzyl alcohol ("peptide-PAB") include valine-citrulline-p-aminobenzylcarbamate, maleimidocaproyl-p-aminobenzylcarbamate, maleimidocaproyl-phenylalanine-lysine-p-aminobenzylcarbamate, and maleimidocaproyl-valine-citrulline-p-aminobenzylcarbamate.

[0085] Examples of bifunctional derivatives include N-[β-maleimidopropyloxy]succinimide ester (BMPS), [N-ε-maleimidocaproyloxy]succinimide ester (EMCS), N-[γ-maleimidobutyryloxy]succinimide ester (GMBS), m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS), [N-ε-maleimidocaproyloxy]sulfosuccinimide ester (sulfo-EMCS), N-[γ-maleimidobutyryloxy]sulfosuccinimide ester (sulfo-GMBS), m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester (sulfo-MBS), N-succinimidyl-3-(2-pyridyldithio) E) propionate (SPDP), succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC), N-succinimidyl-4-(2-pyridylthio)pentanoate (SPP), iminothiolane (IT), imidoesters (dimethyl adipimidate HCl, etc.), active esters (disuccinimidyl sulfate, etc.), aldehydes (glutaraldehyde, etc.), bis-azido compounds (bis(p-azidobenzoyl)hexanediamine, etc.), bis-diazonium derivatives (bis-(p-diazoniumbenzoyl)-ethylenediamine, etc.), diisocyanates (toluene 2,6-diisocyanate, etc.), his-active fluorine compounds (1,5-difluoro-2,4-Dinitrobenzene, etc.), DBCO-NHS Ester, DBCO-C6-NHS Ester, DBCO-Sulfo-NHS Ester, DBCO-PEG4-NHS Ester, DBCO-PEG5-NHS Ester, Sulfo DBCO-TFP Ester, Sulfo DBCO-PEG4-TFP Ester, DBCO-PEG5-TFP Ester, DBCO-STP Ester, DBCO Acid, DBCO-C6-Acid, DBCO-PEG5-Acid, DBCO Amine, DBCO-PEG4-Amine, Sulfo DBCO-Amine, DBCO Maleimide, Sulfo Examples include DBCO-Maleimide, DBCO-PEG4-Maleimide, BCN-PEG3-Val-Cit, DBCO-PEG4-Val-Cit-PAB-PNP, and TCO-PEG4-Val-Cit-PAB-PNP.

[0086] Further examples include triazole and oxime / hydrazone bonds formed by bioorthogonal reactions, such as the Huisgen reaction between azide and alkyne. Furthermore, alkylene bonds, polyethylene glycol (PEG) bonds, disulfide bonds, thioether bonds, and the like can be used alone or in combination. A preferred combination is represented by the following formula (a):

[0087]

[0088] [In the formula, J 1 is a target recognition molecule or a binding site for a drug, and J 2 is the bond to the copolymer X, and Ak 2 , Ak 3 are each independently a single bond or C 1-7 represents an alkylene bond, and B 1 , B 2 each independently represents a single bond, an amide bond, or an ester bond; L 1 is a single bond, -(CH2CH2O) o CH2CH2-, phenylene, cyclohexylene, -NH-peptide-CO-, or phenylene-NH-peptide-CO-, and o represents an integer of 0 to 100.

[0089] In general formula (a), J 1 is a binding site for a target recognition molecule or a drug, and is —CO—, —S—, —CO—O—, —CO-Ak 4 —O—, or the following formula (a′):

[0090]

[0091] [In the formula, * 1 indicates binding to a target recognition molecule or a drug, and * 2 Ak 2 and the like, which shows a bond with

[0092] In general formula (a), Ak 2 , Ak 3 , Ak 4 are each independently a single bond or C 1-7 Indicates an alkylene bond.

[0093] In general formula (a), B 1 , B 2 each independently represents a single bond, an amide bond, or an ester bond.

[0094] In general formula (a), L 1 is a single bond, -(CH2CH2O) o It represents CH2CH2-, phenylene, cyclohexylene, -NH-peptide-CO-, or phenylene-NH-peptide-CO-, and o represents an integer of 0 to 100. A peptide is 2 to 5 amino acid residues.

[0095] In general formula (a), J 2 is a bonding site to the copolymer X, and is a single bond, a bond containing triazole formed by the Huisgen reaction between an azide and a functional group containing an alkyne, or a bond represented by the following formula (a″):

[0096]

[0097] [In the formula, * 3 indicates a bond with copolymer X, * 4 Ak 3 The bond with is shown.

[0098] In a more preferred combination, the bond between the antibody and the copolymer X includes a "triazole-containing bond formed by, for example, the Huisgen reaction between an azide and a functional group containing an alkyne," and is represented by the following formula (b):

[0099]

[0100] [In the formula, J 3 is the binding site with the target recognition molecule, and Ak 6 is a single bond or C 1-7 represents an alkylene bond, and B 3 represents a single bond, an amide or an ester bond, J 4 represents a bond containing triazole formed by, for example, a Huisgen reaction between an azide and a functional group containing an alkyne, and p and q each independently represent an integer of 0 to 100.

[0101] In general formula (b), J 3 is a linking portion to a target recognition molecule, and is —CO— or the following formula (b′):

[0102]

[0103] [In the formula, * 5 indicates binding to the target recognition molecule, * 6 Ak 6 The bond with is shown.

[0104] In general formula (b), Ak 6 represents a single bond or a C1-7 alkylene bond.

[0105] In general formula (b), B 3 , B 4 each independently represents a single bond, an amide bond, or an ester bond.

[0106] In formula (b), p and q each independently represent an integer of 0 to 100, preferably an integer of 1 to 50, and more preferably an integer of 2 to 25.

[0107] In general formula (b), J 4 is a bonding site to the copolymer X, and is a triazole-containing bond formed by, for example, a Huisgen reaction between an azide and a functional group containing an alkyne, and is represented by the following formula (b″):

[0108]

[0109] [In the formula, * 7 represents a bond with —CO— in general formula (b), and * 8 represents a bond to the copolymer X].

[0110] Further, more preferred examples of the bond between the target recognition molecule and the copolymer X include those represented by the following formulas (6) to (13):

[0111]

[0112] [In the formula, * 7 indicates binding to the target recognition molecule, * 8 represents a bond to the copolymer X].

[0113] Furthermore, a preferred combination of the bond between the drug and the copolymer X is the following formula (c):

[0114]

[0115] [In the formula, J 5 is the bond with copolymer X, and J 6 is the binding site to the drug, and Ak 7 , Ak 8 are each independently a single bond or C 1-7 represents an alkylene bond, and B 5 represents a single bond, an amide bond, or an ester bond; L 2 represents a single bond, phenylene, cyclohexylene, —CO-peptide-NH—, or —CO-peptide-NH-phenylene.

[0116] In general formula (c), J 5 is a bond to the copolymer X, and is a single bond or a group represented by the following formula (c'):

[0117]

[0118] [In the formula, * 9 indicates a bond with copolymer X, * 10 Ak 7 The bond with is shown.

[0119] In general formula (c), Ak 7 , Ak 8 , Ak 9 , Ak 10 are each independently a single bond or C 1-7 Indicates an alkylene bond.

[0120] In general formula (c), B 5 represents a single bond, an amide, or an ester bond.

[0121] In general formula (c), L 2 represents a single bond, phenylene, cyclohexylene, -CO-peptide-NH-, or -CO-peptide-NH-phenylene. A peptide is 2 to 5 amino acid residues.

[0122] In general formula (c), J 6 is a binding site to a drug, and is —CO—, —S—, —O—CO—, —O—Ak 10 -CO-, or the following formula (c"):

[0123]

[0124] [In the formula, * 11 indicates binding to the drug, * 12 Ak 8 and preferably contains a "disulfide bond" with a sulfur atom derived from the drug.

[0125] Further, more preferred examples of the bond between the drug and the copolymer X include those represented by the following formulas (14) to (22):

[0126]

[0127] [In the formula, * 13 indicates a bond with copolymer X, * 14 indicates a bond to a drug].

[0128] When the compound of the present invention has geometric or optical isomers, the mixture or separated form of these isomers also falls within the scope of the present invention. Separation of isomers can be carried out by conventional methods.

[0129] The target-recognizing copolymer of the present invention can be produced by various known methods. The production method is not particularly limited, but it can be produced, for example, according to the synthesis method of click reaction described below.

[0130]

[0131] wherein R′ is a hydrogen atom or C 1-3 R" represents an alkyl group, 4 , R 5 or R 6 and Ab represents a target recognition molecule.

[0132] The SH group of the target recognition molecule can be obtained by reducing the disulfide bond between the cysteine ​​residues that connect the chains. Examples of reducing agents include tricarboxyethylphosphine (TCEP), 2-mercaptoethanol, 2-mercaptoethylamine, cysteine ​​hydrochloride, dithiothreitol, or salts thereof (e.g., hydrochlorides). This method involves mixing a solution containing the target recognition molecule with a solution containing a reducing agent. In addition to producing a partially reduced antibody, a linker-linked (modified) target recognition molecule can be produced by reacting the target recognition molecule with a linker having a functional group that reacts with the SH group. The concentration of the target recognition molecule in this reaction is, for example, 1 mg / mL to 100 mg / mL. The concentration of the reducing agent is, for example, 1 mM to 100 mM, and the reducing agent can be mixed in excess of the target recognition molecule. The reducing agent can be used in an amount ranging from 1 to 50 times the molar equivalent of the target recognition molecule, for example, 2 to 30 times the molar equivalent, 5 to 20 times the molar equivalent, 7 to 13 times the molar equivalent, or 10 times the molar equivalent. The reaction can be performed by heating to a temperature that does not denature the protein, for example, in the range of 1 to 37°C, and the reaction time can be adjusted depending on the amount of reducing agent. For example, the reaction time is from a few seconds to 5 minutes, or from a few seconds to 2 minutes, preferably from 1 to 5 minutes, and more preferably from 1 to 2 minutes.

[0133] When complexing a target recognition molecule with SCNP by covalent bonding, a functional group for complexing the SCNP surface is introduced to allow the complexing reaction to occur, and the complexation can be carried out by reacting with an SH group, amino group, or carboxyl group at the end or side chain of the target recognition molecule that can react with the functional group. Alternatively, a spacer can be introduced into the end or side chain of the target recognition molecule using an appropriate crosslinking reagent (crosslinker), forming a covalent bond with the SCNP as a modified target recognition molecule. Examples of such bond formation include click chemistry between an azide group and an alkyne, a reaction between a sulfhydryl group and a maleimide group, and a reaction between an amino group and a succinimidyl group.

[0134] "Click chemistry" is a class of reactions that resemble natural biochemical reactions and have the following attributes: they are highly efficient reactions that proceed rapidly to high yields, and they are highly selective, producing no (or few) by-products and tolerating multiple functional groups. Furthermore, they are reactions that proceed under mild reaction conditions, such as low temperature (or ambient temperature), or in aqueous solution. The reaction can be carried out in water or in solvents such as alcohols, such as methanol, ethanol, 1-propanol, and 2-propanol; ethers, such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; aromatic hydrocarbons, such as benzene, toluene, and xylene; halogenated hydrocarbons, such as dichloromethane, chloroform, and 1,2-dichloroethane; N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and ethyl acetate; and preferably, water or N,N-dimethylformamide is used as the solvent. In some embodiments, the cyclooctyne is dibenzocyclooctyne (DBCO), difluorobenzocyclooctyne (DIFBO), biarylazacyclooctynone (BARAC), dibenzocyclooctyne (DIBO), difluorinated cyclooctyne (DIFO), monofluorinated cyclooctyne (MOFO), dimethoxyazacyclooctyne (DIMAC), or aryl-less octyne (ALO), with dibenzocyclooctyne (DBCO) being preferred. In some embodiments, the alkyne is an aliphatic alkyne, and the reacting step is carried out in the presence of a copper(I) catalyst. In some embodiments, the alkyne is cyclooctyne, and the reacting step is carried out under copper-free conditions. The reaction temperature is 0 to 300°C, preferably 0 to 150°C, and more preferably 1 to 100°C, and the reaction time is 1 minute to 48 hours, preferably 5 minutes to 24 hours. The reaction in the above reaction scheme is a Huisgen cycloaddition, which is a type of click reaction, and is a 1,3-dipolar cycloaddition reaction that forms a 1,2,3-triazole from an azide and an alkyne.

[0135] The polymer X, target-recognizing copolymer, and target-recognizing micelle-drug complex of the present invention produced can be purified by a polymer isolation and purification method generally known in the field of polymer chemistry.Specific examples include extraction, recrystallization, salting out with ammonium sulfate or sodium sulfate, centrifugation, dialysis, ultrafiltration, adsorption chromatography, ion exchange chromatography, hydrophobic chromatography, normal phase chromatography, reverse phase chromatography, desalting column chromatography, gel filtration, gel permeation chromatography, affinity chromatography, electrophoresis, countercurrent distribution, and combinations thereof.In particular, in hydrophobic chromatography, the retention time changes depending on the number of SCNPs bound per target recognition molecule, so that fractions satisfying any DAR can be collected by fractionation.

[0136] The copolymer X and target-recognizing copolymer of the present invention can be used as carriers for transporting various physiologically active substances (drugs). For example, a pharmaceutical composition comprising the copolymer X, target-recognizing copolymer, or target-recognizing micelle-drug complex of the present invention carrying (encapsulating) a tumor therapeutic drug inhibits tumor growth, as confirmed in the test examples described below, and can therefore be used as a preventive and / or therapeutic agent for various cancer diseases such as colon cancer, duodenal cancer, gastric cancer, pancreatic cancer, liver cancer, lung cancer, uterine cancer, and ovarian cancer. Furthermore, due to their high tumor accumulation ability, they can be used as diagnostic agents and contrast agents for tumors.

[0137] When the copolymer and target-recognizing copolymer of the present invention are used as drug delivery carriers, the dosage and frequency of administration may be appropriately selected taking into consideration the dosage form, the age and body weight of the patient, the nature or severity of the symptoms to be treated, and the like, and the dosage and frequency of administration should not be limited. However, when a drug-encapsulating polymer or a target-recognizing micelle-drug complex is intravenously injected as an injection, for example, an amount of 0.12 mg to 12,000,000 mg is preferably administered per adult (60 kg) in a single administration, more preferably 1.2 mg to 1,200,000 mg, and particularly preferably 12 to 120,000 mg.

[0138] The pharmaceutical composition of the present invention can be produced by mixing a drug with the copolymer X, target-recognizing copolymer, or target-recognizing micelle-drug complex of the present invention. Preferably, the copolymer, target-recognizing copolymer, or target-recognizing micelle-drug complex of the present invention is mixed with the drug to produce a single-chain nanoparticle, or a single-chain nanoparticle of the copolymer X, target-recognizing copolymer, or target-recognizing micelle-drug complex of the present invention is produced and then the drug is mixed. Single-chain nanoparticles can be produced by known methods. In the pharmaceutical composition of the present invention, the drug may be supported on the copolymer X, target-recognizing copolymer, or target-recognizing micelle-drug complex by electrostatic interaction, hydrogen bond, hydrophobic interaction, covalent bond, or the like.

[0139] The drug is preferably an anticancer drug, more preferably an anticancer drug that acts on cancer cells to suppress their proliferation, and examples thereof include antimetabolites, alkylating agents, anthracyclines, antibiotics, mitotic inhibitors, topoisomerase inhibitors, proteasome inhibitors, antihormones, etc. Examples of antimetabolites include azathioprine, 6-mercaptopurine, 6-thioguanine, fludarabine, pentostatin, cladribine, 5-fluorouracil (5FU), floxuridine (FUDR), cytosine arabinoside (cytarabine), methotrexate, trimethoprim, pyrimethamine, pemetrexed, etc. Examples of alkylating agents include cyclophosphamide, mechlorethamine, uramustine, melphalan, chlorambucil, thiotepa / chlorambucil, ifosfamide, carmustine, lomustine, streptozocin, busulfan, dibromomannitol, cisplatin, carboplatin, nedaplatin, oxaliplatin, miriplatin, satraplatin, triplatin tetranitrate, procarbazine, altretamine, dacarbazine, mitozolomide, trabectedin, temozolomide, etc. Examples of anthracyclines include daunorubicin, doxorubicin, epirubicin, idarubicin, valrubicin, aclarubicin, amrubicin, pirarubicin, etc. Examples of antibiotics include dactinomycin, bleomycin, mithramycin, anthramycin, streptozotocin, gramicidin D, staurosporine, mitomycins (eg, mitomycin C), duocarmycins (eg, CC-1065), and calicheamicins.Mitotic inhibitors include maytansinoids (e.g., DM0, mertansine (also known as DM1), DM2, DM3, DM4, or emtansine), auristatins (e.g., auristatin E, auristatin phenylalanine phenylenediamine (AFP), monomethyl auristatin E, monomethyl auristatin D, and monomethyl auristatin F), dolastatins, cryptophycins, vinca alkaloids (e.g., vincristine, vinblastine, vindesine, vinorelbine), taxanes (e.g., paclitaxel, docetaxel), and colchicines. Topoisomerase inhibitors include irinotecan, topotecan, nogitecan, amsacrine, etoposide, teniposide, mizanthrone, mitoxantrone, SN-38, exatecan, and deruxtecan. Examples of proteasome inhibitors include peptidylboronic acid, carfilzomib, bortezomib, etc. Examples of antihormonal agents include fulvestrant, tamoxifen, toremifene, etc. When these drugs are formulated into the pharmaceutical composition of the present invention, one or more of them can be used in combination, and the drug may be supported on the copolymer in its free form.

[0140] The administration route of the pharmaceutical composition of the present invention is preferably the most effective route for treatment, and can be a parenteral administration route such as an oral administration route, an injection route, or a transdermal administration route, but parenteral administration such as intraarterial injection, intravenous injection, subcutaneous injection, intramuscular injection, or intraperitoneal injection is preferred, with intraarterial injection and intravenous injection being more preferred. The number of administrations is not limited, but examples include administration once to several times per week on average.

[0141] Various formulations suitable for the administration route can be produced by a conventional method by appropriately selecting formulation additives commonly used in formulations, such as excipients, fillers, binders, wetting agents, disintegrants, lubricants, surfactants, dispersants, buffers, preservatives, solubilizing agents, antiseptics, flavoring agents, soothing agents, stabilizers, and isotonicity agents.

[0142] The formulation additives that can be contained in the various formulations described above are not particularly limited as long as they are pharmaceutically acceptable. Examples of such formulation additives include purified water, water for injection, distilled water for injection, pharmaceutically acceptable organic solvents, collagen, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, sodium alginate, water-soluble dextran, sodium carboxymethyl starch, pectin, xanthan gum, gum arabic, casein, gelatin, agar, glycerin, propylene glycol, polyethylene glycol, petrolatum, paraffin, stearyl alcohol, stearic acid, human serum albumin, mannitol, sorbitol, lactose, etc. The additives used can be appropriately selected depending on the type of formulation and can be used alone or in combination.

[0143] Injectable preparations can also be prepared as suspensions or emulsions using non-aqueous diluents (e.g., polyethylene glycol, vegetable oils such as olive oil, alcohols such as ethanol, etc.). Injectable preparations can be sterilized by filtration sterilization using a filter or by incorporating a disinfectant or the like. Injectable preparations can also be produced in a form that is prepared just before use. That is, a sterile solid composition can be prepared by freeze-drying or the like, and then dissolved in water for injection, distilled water for injection, or other solvent before use.

[0144] The present invention will be described in more detail below with reference to examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present invention.

[0145] Example 1: Preparation of poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(1-ethoxyethyl acrylate)] (1) Synthesis of 1-Ethoxyethyl acrylate (EEA) Under an argon atmosphere, ethyl vinyl ether (28.725 mL) was weighed out, and phosphoric acid (50 mg) was added under ice cooling. Then, acrylic acid (17.15 mL) was added, and the mixture was stirred at room temperature for 48 hours. Hydrotalcite (3 g) was added, and the mixture was further stirred for 2 hours, and the reaction was stopped. After filtration through Celite, unreacted ethyl vinyl ether was removed by evaporation. Phenothiazine was added as a polymerization inhibitor to a concentration of 500 ppm, and the mixture was purified by vacuum distillation with calcium hydride (distillation temperature: 28-32°C). The resulting 1-ethoxyethyl acrylate was dispensed into glass vials and stored at -30°C. 13 C NMR (400MHz, CDCl3), δ, ppm: 15.29 (-OCH2CH3), 21.16 (-COOCH(CH3)), 64.98 (-O CH2-), 96.73 (-COOCH(CH3)), 128.84 (CH2CH-), 131.43 (CH2CH-), 166.00 (-COO).

[0146] (2) Synthesis of poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(1-ethoxyethyl acrylate)] 100 mg of 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) was weighed out and dissolved in 17.3 mL of toluene to prepare a DDMAT / toluene stock solution (DDMAT concentration: 5.78 mg / mL). Similarly, 22 mg of 2,2'-Azobis(2-methylpropionitrile) (AIBN) was weighed and dissolved in 17.3 mL of toluene to prepare an AIBN / toluene stock solution (AIBN concentration: 1.27 mg / mL). Separately, 1.296 g of poly(ethylene glycol) methyl ether acrylate (mPEGA, the average number of repeating units (n) of ethylene glycol is 9), 0.394 g of benzyl acrylate (BnA), 0.039 g of 1-ethoxyethyl acrylate, 1.73 mL of DDMAT / toluene stock solution, and 1.73 mL of AIBN / toluene stock solution were added, and polymerization was carried out in an oil bath at 70° C. After 90 minutes, the polymerization was stopped, and the copolymer was recovered by reprecipitation or dialysis against methanol. Since the obtained copolymer was basically a viscous body, the reprecipitation method involved dropping the reaction solution into a centrifuge tube containing a poor solvent (hexane / ethyl acetate = 7 / 3 [v / v]) and recovering it by centrifugation (2,000 × g, 5 min). This procedure was repeated three times, and finally vacuum drying was carried out to obtain 1.223 g of poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(1-ethoxyethyl acrylate)]. The obtained copolymer was measured using NMR. 1 The degree of polymerization of each monomer and the number average molecular weight (M n,NMRAs a result of analyzing the mPEGA (n=9), the degree of polymerization was 102, the degree of polymerization of BnA was 94, and the degree of polymerization of EEA was 9. n,NMR Furthermore, the molecular weight dispersity (M w / M n ) was measured and found to be 1.53.

[0147]

[0148] [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d6 containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25 °C Number of accumulations: 256 Results: Figure 1 (2) GPC measurement Apparatus: HPLC-Prominence system / Shimadzu Corporation Detector: RID-10A Refractive index detector / Shimadzu Corporation Column: TSKgel α-2500 column / Tosoh (column size 7.8 mm × 300 mm, particle size 7 μm, exclusion limit molecular weight 5 × 10 3 ) TSKgel α-4000 column / Tosoh (column size 7.8 mm x 300 mm, particle size 10 μm, exclusion limit molecular weight 4 x 10 5 ) TSKgel guard column / Tosoh Mobile phase: N,N-dimethylformamide (DMF) containing 10 mmol / L lithium bromide Temperature: 40°C Flow rate: 0.5 mL / min Sample concentration: 6 mg / mL Standard substance: Poly(methyl methacrylate) standard ReadyCal set, M p 800-2,200,000 Da / SIGMA Results: Figure 2

[0149]

[0150] [Examples 2 to 68] Polymers with different composition ratios and average molecular weights, as shown in the table below, were produced using the same method as in Example 1, except that the types, amounts, reaction temperatures, and polymerization times of the monomers (mPEGA, BnA, EEA) used in Example 1 were appropriately changed.

[0151]

[0152]

[0153] Example 69 Production of poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] The poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(1-ethoxyethyl acrylate)] obtained in Example 1 was treated with 0.5 N HCl at room temperature to eliminate the ethoxyethyl groups, thereby obtaining 1.176 g of a terpolymer having carboxyl groups. The Z-average particle size and polydispersity index of the resulting terpolymer in water were measured by dynamic light scattering (DLS) and were found to be 8.5 nm (polydispersity index 0.14).

[0154]

[0155] [Measurement equipment and conditions] (1) DLS measurement Equipment: Zetasizer NanoZS / Malvern Instruments Ltd. Measurement temperature: 25°C Sample concentration: 10 mg / mL Results: Figure 3

[0156] Example 70: Method for producing (1,2-diaminocyclohexane)platinum(II)-encapsulated SCNP 65.28 mg of the Cl(HO) form (DACHPt.Cl.HO) of (1,2-diaminocyclohexane)platinum(II) (hereinafter abbreviated as DACHPt) was dissolved in 20 mL of purified water and stirred at 70°C for 2 hours. To 5 mL of this solution, 287.4 mg of the terpolymer obtained in Example 69 was added, and the mixture was stirred overnight at 50°C. After stirring was completed, the reaction solution was purified by dialysis using purified water as the external solution, and 5 mL of DACHPt-encapsulated SCNP was obtained. The Pt content of the DACHPt-encapsulated SCNP obtained after purification was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) and was 720 μg / mL (1.14 mg / mL as DACHPt). Separately, 200 μL of the DACHPt-encapsulated SCNP was freeze-dried, the solids concentration was calculated, and the ratio to the Pt content was taken to calculate the amount of Pt bound per polymer, which was 3.4 mol / mol. Furthermore, the Z-average particle size and polydispersity index of the obtained DACHPt-encapsulated SCNP were measured by dynamic light scattering (DLS) and were found to be 8.7 nm (polydispersity index 0.14). The particle sizes of SCNP before and after DACHPt encapsulation are shown in Figure 3. The particle size of SCNP hardly changed before and after DACHPt encapsulation. The results are summarized in the table below.

[0157] [Measurement equipment and conditions] (1) ICP-AES measurement Equipment: Sequential high-frequency plasma emission device ICPE-9000 / Shimadzu Corporation Pretreatment equipment: Microwave sample pretreatment equipment ETHOS EASY / Milestone General Measurement wavelength: 214 nm Standard solution: Platinum standard solution (Pt1000) for ICP analysis / Fujifilm Wako Pure Chemicals 2) DLS measurement Equipment: Zetasizer NanoZS / Malvern Instruments Ltd. Measurement temperature: 25 °C Sample concentration: 10 mg / mL Results: Figure 3

[0158]

[0159] Example 71 Preparation of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] Synthesis was carried out in the same manner as in Examples 1 and 69, except that N3-CTA was used instead of the chain transfer agent DDMAT used in Example 1. 100 mg of 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 3-azido-1-propanol ester (N3-CTA) was weighed out and dissolved in 17.3 mL of toluene to prepare an N3-CTA / toluene stock solution (N3-CTA concentration: 5.78 mg / mL). Similarly, 10 mg of 2,2'-Azobis(2-methylpropionitrile) (AIBN) was weighed out and dissolved in 7.87 mL of toluene to prepare an AIBN / toluene stock solution (AIBN concentration: 1.27 mg / mL). Separately, 2.592 g of poly(ethylene glycol) methyl ether acrylate (mPEGA, the average number of repeating units (n) of ethylene glycol is 9), 0.684 g of benzyl acrylate (BnA), 0.172 g of 1-ethoxyethyl acrylate, 4.15 mL of N3-CTA / toluene stock solution, and 3.46 mL of AIBN / toluene stock solution were added, and polymerization was carried out in an oil bath at 70° C. After 90 minutes, the polymerization was stopped, and the copolymer was recovered by reprecipitation or dialysis against methanol. For the reprecipitation method, the reaction solution was dropped into a centrifuge tube containing a poor solvent (hexane / ethyl acetate = 7 / 3 [v / v]), and the product was recovered by centrifugation (2,000 × g, 5 min). This procedure was repeated three times, and finally, the product was dried in vacuo. The resulting copolymer was treated with 0.5 N HCl at room temperature to remove the ethoxyethyl groups, yielding 2.455 g of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)].The copolymer obtained was measured by NMR. 1 The degree of polymerization of each monomer and the number average molecular weight (M n,NMR As a result of analyzing the mPEGA (n=9), the degree of polymerization was 70, the degree of polymerization of BnA was 56, and the degree of polymerization of EEA was 15. n,NMR Furthermore, the molecular weight dispersity (M w / M n ) was measured and found to be 1.32.

[0160]

[0161] [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25 °C Number of accumulations: 256 Results: Figure 4 (2) GPC measurement Apparatus: HPLC-Prominence system / Shimadzu Corporation Detector: RID-10A Refractive index detector / Shimadzu Corporation Column: TSKgel α-2500 column / Tosoh (column size 7.8 mm × 300 mm, particle size 7 μm, exclusion limit molecular weight 5 × 10 3 ) TSKgel α-4000 column / Tosoh (column size 7.8 mm x 300 mm, particle size 10 μm, exclusion limit molecular weight 4 x 10 5 ) TSKgel guard column / Tosoh Mobile phase: N,N-dimethylformamide (DMF) containing 10 mmol / L lithium bromide Temperature: 40°C Flow rate: 0.5 mL / min Sample concentration: 6 mg / mL Standard substance: Poly(methyl methacrylate) standard ReadyCal set, M p 800-2,200,000 Da / SIGMA Results: Figure 5

[0162]

[0163] Examples 72 to 85 Polymers with different composition ratios and average molecular weights, as shown in the table below, were produced in the same manner as in Example 71, except that the amounts of the monomers (mPEGA, BnA, EEA) used in Example 71 and the polymerization time were appropriately changed.

[0164]

[0165]

[0166] [Examples 86-88] N3(PEG m Preparation of 2-(2-(2-azidoethoxy)ethoxy)ethyl ester (N3-PEG2-Ester CTA), 2-(2-(2-azidoethoxy)ethoxy)ethyl ester (N3-PEG2-Ester CTA), 2-(2-(2-azidoethoxy)ethoxy)ethyl ester (N3-PEG2-Ester CTA), 2-(2-(2-azidoethoxy)ethoxy)ethyl ester (N3-PEG2-Ester CTA) The synthesis was carried out under the same (feed ratio) conditions as in Example 83 using 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 23-azido-3,6,9,12,15,18,21-heptaoxatricosan-1-ol ester (N-PEG-Ester CTA) or 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 23-azido-3,6,9,12,15,18,21-heptaoxatricosan-1-ol ester (N-PEG-Ester CTA).

[0167]

[0168]

[0169] [Examples 89-91] N3(PEG mPreparation of N-(8-Azido-3,6-dioxaoctan-1-yl)-2-(dodecylthiocarbonothioylthio)-2-methylpropanamide (N-PEG2-Amide)-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] Instead of the chain transfer agent N-CTA used in Example 71, N-(8-Azido-3,6-dioxaoctan-1-yl)-2-(dodecylthiocarbonothioylthio)-2-methylpropanamide (N-PEG2-Amide)-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)] CTA), N-(17-Azido-3,6,9,12,15-pentaoxaheptadecan-1-yl)-2-(dod carbonothioylthio)-2-methylpropanamide (N3-PEG5-Amide CTA), or N-(23-Azido-3,6,9,12,15,18,21-heptaoxatricosan-1-yl)-2-( dodecylthiocarbonothioylthio)-2-methylpropanamide (N3-PEG7-Amide CTA) under the same conditions (feed ratio) as in Example 83.

[0170]

[0171]

[0172] Example 92 Production of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)]-isobutylonitrile 2.40 g of the copolymer obtained in Example 71 was weighed out and dissolved in 32 mL of toluene. To this solution, 170 mg of AIBN and 62 mg of lauroyl peroxide were added, and the mixture was stirred in an oil bath at 80°C for 20 hours. The reaction was stopped by cooling on ice, and the copolymer was recovered by reprecipitation or dialysis against methanol. Since the obtained copolymer was essentially a viscous body, for the reprecipitation method, the reaction solution was dropped into a centrifuge tube containing a poor solvent (hexane / ethyl acetate = 7 / 3 [v / v]), and the reaction mixture was recovered by centrifugation (2,000 × g, 5 min). This procedure was repeated three times, and finally the mixture was dried in vacuo to obtain 2.21 g of N3-poly[(benzyl acrylate)-co-(poly(ethylene glycol) methyl ether acrylate)-co-(acrylic acid)]-isobutylonitrile, in which the terminal structure had been converted. The residual rate of the terminal structure of the obtained copolymer was evaluated from the UV spectrum measured using an ultraviolet-visible spectrophotometer, and the result was 0.0%.

[0173]

[0174] [Measurement equipment and conditions] (1) UV spectrum measurement Equipment: Hitachi spectrophotometer U-9300 / Hitachi Solvent: Purified water Sample concentration: 4 mg / mL Measurement wavelength: 250-500 nm Results: Figure 6

[0175]

[0176] [Examples 93 to 95] Copolymers with different terminal structures shown in the table below were synthesized using the same method as in Example 92, except that the type and amount of azo compound added to the copolymers obtained in Examples 84 and 85 were appropriately changed.

[0177]

[0178] Example 96 Preparation of DM1-Cysteamine-Conjugated Copolymer 200 mg of the copolymer obtained in Example 92 was weighed and dissolved in 2 mL of DMF. 59 mg of (1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate (COMU) and 23.2 μL of 2,2,6,6-tetramethylpiperidine (TMP) were added, and the mixture was stirred at 30°C for 2 hours. Separately, 101 mg of mertansine (DM1) and 18 mg of S-(2-pyridylthio)cysteamine hydrochloride were added and dissolved in 3 mL of THF. 35.9 μL of DIPEA was added, and the mixture was stirred at 30°C for 2 hours. The respective reaction solutions were mixed, and the resulting reaction solution was stirred at 30°C for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and then the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 222 mg of DM1-cysteamine-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS), and were found to be 11 nm (polydispersity index: 0.32).

[0179]

[0180] DM1-cysteamine-bound copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 13 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 7

[0181]

[0182] [Examples 97 to 107] For the copolymers obtained in Examples 79, 85 to 91, and 93 to 95, the amounts of linker and DM1 added were appropriately changed, and copolymers having different numbers of DM1 introduced per copolymer molecule, as shown in the table below, were synthesized using the same method as in Example 96.

[0183]

[0184] Example 108: Preparation of DM1-N-4-APM-linked copolymer 509 mg of the copolymer obtained in Example 72 was weighed and dissolved in 10 mL of DMF. 84 mg of COMU and 33 μL of TMP were added, and the mixture was stirred at room temperature for 3 hours. 55 mg of N-(4-Aminophenyl)maleimide (N-4-APM) was then added, and the mixture was stirred at 30°C for 3 days. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to obtain 475 mg of N-4-APM-linked copolymer. 475 mg of the resulting N-4-APM-linked copolymer was dissolved in 10 mL of DMF, and 102 mg of DM1 was added. The mixture was stirred at room temperature for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to obtain 458 mg of DM1-N-4-APM-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and found to be 11 nm (polydispersity index: 0.19).

[0185]

[0186] The DM1-N-4-APM linked copolymer was measured using NMR. 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 7 mol / mol. [Measurement equipment and conditions] (1) 1H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 8

[0187]

[0188] Example 109 Synthesis of 1,4-diaminobutane-linked copolymer 810 mg of the copolymer obtained in Example 74 was weighed and dissolved in 16 mL of DMF. 164.9 mg of COMU and 78 μL of TMP were added, and the mixture was stirred at room temperature for 3 hours. Subsequently, 735 μL of N-(tert-Butoxycarbonyl)-1,4-diaminobutane was added, and the mixture was stirred at 30°C for 3 days. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer. The obtained N-Boc-1,4-diaminobutane copolymer was dissolved in 32 mL of a mixture of DCM and TFA [DCM / TFA=5 / 3 (v / v)] and stirred at room temperature overnight to carry out deprotection, and then the solvent was removed by distillation under reduced pressure and drying in vacuo to obtain 643 mg of a 1,4-diaminobutane-bound copolymer.

[0189]

[0190] The 1,4-diaminobutane-linked copolymer was measured using NMR. 1 The number of 1,4-diaminobutane introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 12 mol / mol. [Measurement equipment and conditions] (1) 1H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 9

[0191]

[0192] Examples 110 to 116 For the copolymers obtained in Examples 73, 75 to 78, and 80 to 81, the amount of N-(tert-Butoxycarbonyl)-1,4-diaminobutane added was appropriately changed, and by using the same method as in Example 109, copolymers having different numbers of 1,4-diaminobutane introduced per copolymer molecule, as shown in the table below, were synthesized.

[0193]

[0194] Example 117: Preparation of DM1-MHA-1,4-diaminobutane-linked copolymer 295 mg of the copolymer obtained in Example 109 was weighed and dissolved in 6 mL of DMF. 59.3 mg of COMU and 28 μL of TMP were added, and the mixture was stirred at room temperature for 3 hours. 293 mg of 6-Maleimidohexanoic Acid (MHA) was then added, and the mixture was stirred at 30°C for 3 days. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to obtain 313 mg of MHA-1,4-diaminobutane-linked copolymer. The resulting MHA-1,4-diaminobutane-linked copolymer was dissolved in 10 mL of DMF, after which 80 mg of DM1 was added and the mixture was stirred at 30°C for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to yield 321 mg of DM1-MHA-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and found to be 10 nm (polydispersity index: 0.21).

[0195]

[0196] DM1-MHA-1,4-diaminobutane-linked copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 12 mol / mol. [Measurement equipment and conditions] (1) 1H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 10

[0197]

[0198] Example 118 Preparation of DM1-SPDP-1,4-diaminobutane-linked copolymer 81 mg of DM1 and 29 mg of 2,5-dioxopyrrolidine-1-yl 3-(pyridin-2-yldisulfanyl)propanoate (SPDP) were added and dissolved in 1 mL of DCM, and 16 μL of N,N-diisopropylethylamine (DIPEA) was added and stirred for 3 hours at 30° C. 200 mg of the copolymer obtained in Example 110 was dissolved in 4 mL of DCM and added to the reaction solution, and the resulting reaction solution was stirred at 30° C. for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 189 mg of DM1-SPDP-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 13 nm (polydispersity index: 0.23).

[0199]

[0200] The DM1-SPDP-1,4-diaminobutane-linked copolymer was measured using NMR. 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 18 mol / mol. [Measurement equipment and conditions] (1) 1H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 11

[0201]

[0202] [Examples 119 to 121] For the copolymers obtained in Examples 112 to 114, the amount of DM1 added was appropriately changed, and copolymers with different numbers of DM1 introduced per copolymer molecule, as shown in the table below, were synthesized using the same method as in Example 118.

[0203]

[0204] Example 122 Preparation of DM1-SMCC-1,4-diaminobutane-linked copolymer 39 mg of DM1 and 15 mg of N-Succinimidyl 4-(N-Maleimidomethyl)cyclohexanecarboxylate (SMCC) were added and dissolved in 1 mL of DCM, and 7.8 μL of DIPEA was added and stirred for 3 hours at 30° C. 96 mg of the copolymer obtained in Example 110 was dissolved in 4 mL of DCM and added to the reaction solution, and the resulting reaction solution was stirred at 30° C. for 48 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 122 mg of DM1-SMCC-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 12 nm (polydispersity index: 0.29).

[0205]

[0206] DM1-SMCC-1,4-diaminobutane-linked copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 18 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 12

[0207]

[0208] [Example 123] By using the same method as in Example 122, but changing the amount of DM1 added to the copolymer obtained in Example 111 as appropriate, copolymers with different numbers of DM1 introduced per copolymer molecule, as shown in the table below, were synthesized.

[0209]

[0210] Example 124 Preparation of DM1-CL-031-1,4-diaminobutane-bound copolymer 81 mg of DM1 and 32 mg of 2,5-dioxopyrrolidine-1-yl 4-(pyridin-2-yldisulfanyl)pentanoate (CL-031) were added and dissolved in 1 mL of DCM, and 16 μL of DIPEA was added and stirred for 3 hours at 30° C. 200 mg of the copolymer obtained in Example 110 was dissolved in 4 mL of DCM and added to the reaction solution, and the resulting reaction solution was stirred at 30° C. for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 222 mg of DM1-CL-031-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 13 nm (polydispersity index 0.34).

[0211]

[0212] DM1-CL-031-1,4-diaminobutane-bound copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 17 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 13

[0213]

[0214] Example 125: Preparation of DM1-CL-018-1,4-diaminobutane-bound copolymer 114 mg of DM1 and 43 mg of 2,5-dioxopyrrolidine-1-yl 3-methyl-3-(pyridin-2-yldisulfanyl)butanoate (CL-018) were added and dissolved in 1 mL of N,N-dimethylacetamide (DMAC), and 8.4 mg of 4-dimethylaminopyridine (DMAP) was added and stirred for 2 hours at 50° C. 150 mg of the copolymer obtained in Example 115 was dissolved in 4 mL of DMAC and added to the reaction solution, and the resulting reaction solution was stirred at 50° C. for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 156 mg of DM1-CL-018-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 13 nm (polydispersity index: 0.23).

[0215]

[0216] DM1-CL-018-1,4-diaminobutane-bound copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 16 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 14

[0217]

[0218] Example 126: Preparation of DM1-CL-038-1,4-diaminobutane-bound copolymer 76 mg of DM1 and 29 mg of 2,5-dioxopyrrolidine-1-yl 4-methyl-4-(pyridin-2-yldisulfanyl)pentanoate (CL-038) were added and dissolved in 1 mL of DMAC, and 6 mg of DMAP was added and stirred for 2 hours at 50° C. 100 mg of the copolymer obtained in Example 115 was dissolved in 4 mL of DMAC, added to the reaction solution, and stirred at 50° C. for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 56 mg of DM1-CL-038-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 11 nm (polydispersity index: 0.32).

[0219]

[0220] DM1-CL-038-1,4-diaminobutane-bound copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 8 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 15

[0221]

[0222] Example 127: Preparation of DM1-CL-047-1,4-diaminobutane-bound copolymer 21.2 mg of 4-succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene (CL-047) was dissolved in 3 mL of DMF, and 100 mg of the copolymer obtained in Example 113 and 10 μL of DIPEA were added thereto, followed by stirring for 24 hours at 30° C. 40 mg of DM1 was added to the reaction solution, and the mixture was stirred at 30° C. for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 153 mg of DM1-CL-047-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 12 nm (polydispersity index: 0.18).

[0223]

[0224] DM1-CL-047-1,4-diaminobutane-bound copolymer was measured using NMR 1 The number of DM1 introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 20 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 16

[0225]

[0226] Example 128: Preparation of SN-38-CO-1,4-diaminobutane-linked copolymer 0.5 g of SN-38 was dissolved in 50 mL of DCM, and 353 mg of di-tert-butyl dicarbonate and 3 mL of pyridine were added, followed by stirring overnight at room temperature. The reaction solution was transferred to a separatory funnel and washed three times with 150 mL of 0.5 N aqueous HCl, followed by washing once with saturated aqueous NaHCO3. The organic layer was recovered, and the DCM was removed under reduced pressure using an evaporator. The resulting solution was then dried in vacuo to obtain 0.586 g of Boc-SN-38. Next, 200 mg of the copolymer obtained in Example 115 was dissolved in benzene and lyophilized. Under an argon atmosphere, this was dissolved in THF, and 27.6 mg of Boc-SN-38, 12 mg of 1,1'-carbonyldiimidazole, and 15 mg of DMAP were added, followed by stirring at room temperature for 3 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was then removed by evaporation under reduced pressure and vacuum drying to recover the Boc-SN-38-CO-1,4-diaminobutane-linked copolymer. The resulting Boc-SN-38-CO-1,4-diaminobutane-linked copolymer was dissolved in 32 mL of a mixture of DCM and TFA [DCM / TFA = 5 / 3 (v / v)] and deprotected by stirring overnight at room temperature. The solvent was then removed by evaporation under reduced pressure and vacuum drying to yield 220 mg of SN-38-CO-1,4-diaminobutane-linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and found to be 8 nm (polydispersity index 0.23).

[0227]

[0228] The SN-38-CO-1,4-diaminobutane-linked copolymer was measured using NMR. 1 The number of SN-38 molecules introduced per copolymer molecule was analyzed by H-NMR spectroscopy and found to be 13 mol / mol. [Measurement equipment and conditions] (1)1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 17

[0229]

[0230] Example 129 Preparation of Deruxtecan-SPDP-1,4-diaminobutane-linked Copolymer 200 mg of the copolymer obtained in Example 116, 14.2 mg of 2,5-dioxopyrrolidine-1-yl 3-(pyridin-2-yldisulfanyl)propanoate (SPDP), and 51.4 mg of Deruxtecan were dissolved in 4 mL of DMF and stirred at 30°C for 2 hours. Thereafter, 1 mL of an aqueous tris(2-carboxyethyl)phosphine (TCEP) solution was added dropwise to the reaction solution with stirring, and the mixture was stirred overnight at 30°C. The resulting reaction solution was stirred at 30°C for 24 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 205 mg of Deruxtecan-SPDP-1,4-diaminobutane-linked copolymer (thioether linkage). The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and found to be 12 nm (polydispersity index: 0.23).

[0231]

[0232] The Deruxtecan-SPDP-1,4-diaminobutane-linked copolymer was measured using NMR. 1 The number of Deruxtecan molecules introduced per copolymer molecule was analyzed by H-NMR spectroscopy and found to be 16 mol / mol. [Measurement equipment and conditions] (1)1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 18

[0233]

[0234] Example 130: Preparation of 4-hydroxybutylamine-linked copolymer 200 mg of the copolymer obtained in Example 82 was weighed and dissolved in 4 mL of DMF. 64.4 mg of COMU and 31 μL of TMP were added, and the mixture was stirred at room temperature for 3 hours. 73 μL of 4-amino-1-butanol was then added, and the mixture was stirred overnight at 30°C. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to obtain 205 mg of 4-hydroxybutylamine-linked copolymer.

[0235]

[0236] The 4-hydroxybutylamine-bound copolymer was measured using NMR. 1 The number of 4-amino-1-butanol introduced per copolymer molecule was analyzed by H-NMR spectrum and found to be 15 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 19

[0237]

[0238] Example 131 Synthesis of Staurosporine (STS)-Conjugated Copolymer 200 mg of the copolymer obtained in Example 130 was dissolved in THF, and 7.2 mg of Triphosgene and 22.1 mg of DMAP were added. The mixture was stirred at 10°C for 30 minutes. 28.2 mg of Staurosporine was then added, and the mixture was stirred at room temperature for 3 hours. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was then removed by distillation under reduced pressure and vacuum drying to obtain 233 mg of Staurosporine-conjugated copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and were found to be 10 nm (polydispersity index: 0.21).

[0239]

[0240] The STS-linked copolymer was measured using NMR. 1 The number of STS molecules introduced per copolymer molecule was analyzed by H-NMR spectroscopy and found to be 13 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 256 Results: Figure 20

[0241]

[0242] Example 132 Preparation of Cetuximab-Maleimide-PEG4-DBCO-Conjugated Micelle-Drug Conjugate To a glass vial containing 3 mL of cetuximab (Erbitux, Merck Biopharmaceuticals) antibody stock solution (10 mg / mL) and 9 mL of PBS, 42 μL of 10 mM tris(2-carboxyethyl)phosphine (TCEP) dissolved in PBS was added and stirred for 15 minutes at 37° C. Then, 99 μL of 10 mM DBCO-PEG4-Maleimide dissolved in DMSO was added, and the mixture was stirred for 15 minutes at 37° C. to react with the cysteine ​​residues of the antibody. 20 μL of an aqueous solution (10 mg / mL) of L-cysteine ​​(168149, Sigma-Aldrich) dissolved in PBS was added, and the mixture was stirred at 37° C. for 1 minute to terminate the reaction. The reaction solution was recovered and dialyzed overnight against purified water (Slide-A-Lyzer). TM Ultrafiltration (Vivaspin Turbo 15, molecular cut-off: 100K) was performed on a Dialysis Cassette (Molecular Cut-off: 20K, 7736, Thermo Fisher Scientific) to remove unreacted modification reagent. The solution was adjusted to exactly 5 mL using PBS, and 1 mL of the solution was dispensed into a glass vial. Subsequently, 10 mg of the copolymer obtained in Example 99 was added, and BICELL TMThe mixture was then left to stand at -20°C for 1 day. It was then thawed at 4°C, and the resulting solution was collected. The copolymer-bound antibody and unbound antibody were separated by hydrophobic chromatography based on the difference in retention time, and the target fractions were collected and washed by ultrafiltration (Vivaspin Turbo 15, molecular cut-off: 100K) using PBS to obtain the target Cetuximab-Maleimide-PEG4-DBCO-linked micellar-drug complex. The Z-average particle size and polydispersity index of the Cetuximab-Maleimide-PEG4-DBCO-linked micellar-drug complex were measured by dynamic light scattering (DLS). Furthermore, the number-average molecular weight (Mn, MALS) of the complex in water was measured by size exclusion chromatography (SEC) equipped with a multi-angle light scattering (MALS) detector, and the absolute molecular weight was calculated. From the molecular weight of the antibody and the molecular weight of the conjugated copolymer, the number of copolymers bound per antibody and the antibody-drug conjugation ratio (DAR) were calculated.

[0243]

[0244] [Measurement equipment and conditions] (1) SEC-MALS measurement Equipment: Waters Alliance / Waters Detector: 2998 PDA detector / Waters 2414 Refractive index detector / Waters DAWN HELEOS II 8+ / WYATT Column: TSKgel G-3000PWXL / Tosoh (column size 7.8 mm x 300 mm, particle size 7 μm, exclusion limit molecular weight 2 x 10 5 ) TSKgel guard column / Tosoh Mobile phase: 100 mmol / L sodium chloride aqueous solution Temperature: 25°C Flow rate: 0.8 mL / min Sample concentration: 10 mg / mL

[0245]

[0246] Examples 133 and 134 Synthesis was carried out in the same manner as in Example 132, except that DBCO-PEG12-Maleimide was used in Example 133, and DBCO-PEG24-Maleimide was used in Example 134 instead of DBCO-PEG4-Maleimide used in Example 132.

[0247]

[0248] Examples 135 to 144 The copolymers obtained in Examples 83, 96, 100, 101, 120, 121, 122, 124, 125 and 128 were synthesized in the same manner as in Example 132, with the amounts of the ingredients changed appropriately.

[0249]

[0250] Example 145 Preparation of Cetuximab-NHS-DBCO-linked Micelle-Drug Conjugate Cetuximab was conjugated to the copolymer obtained in Example 118. To a glass vial containing 14.5 mL of a PBS solution of cetuximab (2.07 mg / mL), 0.5 mL of Sulfo DBCO-NHS Ester dissolved in PBS at 1.22 mg / mL was added and stirred for 3 hours to react with the lysine residues of the antibody. Thereafter, unreacted modifying reagent was removed by dialysis purification (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: purified water) and ultrafiltration (Vivaspin Turbo 15, molecular cut-off: 100K). The solution was adjusted to exactly 5 mL using PBS. 1 mL of the solution was dispensed into glass vials (6 mg of antibody per vial) and recovered by lyophilization. The target Cetuximab-NHS-DBCO-bound micelle-drug complex was then recovered by the same procedure as in Example 132. The Z-average particle size and polydispersity index of the cetuximab-NHS-DBCO-linked micelle-drug complex were measured by dynamic light scattering (DLS) and found to be 32 nm (polydispersity index 0.47). The absolute molecular weight was calculated by MALS measurement, and the number of copolymers bound per antibody calculated from the antibody molecular weight and the molecular weight of the conjugated copolymer was 1.9, resulting in an antibody-drug conjugation ratio (DAR) of 34.

[0251]

[0252] [Examples 146 to 148] Instead of Sulfo DBCO-NHS Ester used in Example 145, DBCO-NHS Ester was used in Example 146, DBCO-PEG5-NHS Ester in Example 147, or DBCO-PEG13-NHS Ester in Example 148, and synthesis was carried out in the same manner as in Example 145.

[0253]

[0254] Examples 149 to 152 Preparation of Trastuzumab-Bound Micelle-Drug Complex The same procedures as in Example 132 were carried out, except that the antibody was changed to trastuzumab (Herceptin, Chugai Pharmaceutical Co., Ltd.).

[0255]

[0256] Example 153 Preparation of Rituximab-S-bound Micelle Drug Complex The same procedure as in Example 132 was carried out, except that the antibody was changed to Rituximab (Rituxan, Zenyaku Kogyo Co., Ltd.).

[0257]

[0258] Example 154 Preparation of Rituximab-NH-bonded micelle-drug complex The same procedure as in Example 146 was carried out, except that the antibody was changed to Rituximab (Rituxan, Zenyaku Kogyo Co., Ltd.).

[0259]

[0260] Example 155 Preparation of Panitumumab-Bound Micelle-Drug Complex The same procedure as in Example 132 was carried out, except that the antibody was changed to panitumumab (Vectibix, Takeda Pharmaceutical Co., Ltd.).

[0261]

[0262] Example 156 Preparation of IgG-bound micelle-drug complex The same procedure as in Example 132 was carried out, except that the antibody was changed to IgG (normal human IgG, whole molecule, purified product, 143-09501, Fujifilm Wako Pure Chemical Industries, Ltd.).

[0263]

[0264] Example 157 Preparation of Cetuximab-Fab-Conjugated Micelle-Drug Complex A cetuximab antibody fragment (Fab) was prepared using a commercially available purification kit (Fab Preparation Kit, Pierce, #44985) and was subjected to the same procedure as in Example 145.

[0265]

[0266] Example 158 Preparation of Exatecan-PAB-Cit-Val-Ahx-linked copolymer Step 1: Synthesis of Boc-Ahx-Val-Cit-PAB-PNP 239 mg of Boc-Ahx-Val-Cit-PAB-OH (HDP 30.1267, a compound described in WO 2016 / 142049) and 362 mg of Bis(4-nitrophenyl)carbonate were dissolved in 1.5 mL of DMF, and 207 μL of N,N-Diisopropylethylamine was added, followed by stirring overnight at room temperature. The reaction mixture was evaporated under reduced pressure using an evaporator and then purified by silica gel column chromatography (CHCl3 / MeOH = 100 / 0 → 85 / 15) to obtain 241 mg of Boc-Ahx-Val-Cit-PAB-PNP.

[0267]

[0268] 1 H NMR (400 MHz, DMSO-d6) δ: 10.06 (s, 1H), 8.33-8.29 (m, 2H), 8.11 (d, J = 7.6Hz, 1H), 7.80 (d, J = 8.5Hz, 1H), 7.65 (d, J = 9.0 Hz, 2H), 7.57 (dt, J = 10.0, 2.7Hz, 2H), 7.41 (d, J = 8.8Hz, 2H), 6.75 (t, J = 5.6Hz, 1H), 5 97 (t, J=5.8Hz, 1H), 5.42 (s, 2H), 5.24 (s, 2H), 4.41-4.34 (m, 1H), 4.20 (dd, J=8.8, 7. 6Hz, 1H), 3.07-2.92 (m, 2H), 2.90-2.85 (m, 2H), 2.23-2.08 (m, 2H), 2.01-1.91 (m, 1H) , 1.75-1.32 (m, 17H), 1.25-1.17 (m, 2H), 0.87 (d, J=6.8Hz, 3H), 0.83 (d, J=6.8Hz, 3H). MS (ESI) m / z: 758.2 [M+H] +

[0269] Step 2: Synthesis of Boc-Ahx-Val-Cit-PAB-Exatecan 240 mg of Boc-Ahx-Val-Cit-PAB-PNP and 168 mg of Exatecan Mesylate were dissolved in 6.33 mL of DMSO, and 88.2 μL of triethylamine was added and stirred overnight at room temperature. Water was added to the reaction solution, and the resulting precipitate was collected by suction filtration. The collected product was purified by silica gel column chromatography (CHCl3 / MeOH = 100 / 0 → 85 / 15) to obtain 202 mg of Boc-Ahx-Val-Cit-PAB-Exatecan.

[0270]

[0271] 1 H NMR (400 MHz, DMSO-d6) δ: 9.98 (s, 1H), 8.09-8.04 (m, 2H), 7.81-7.76 (m, 2H), 7.61 (d, J = 8.5Hz, 2H), 7.36 (d, J = 8.5Hz, 2H ), 7.31 (s, 1H), 6.74 (t, J = 5.6Hz, 1H), 6.52 (s, 1H), 5.97 (t, J = 5.8Hz, 1H), 5.45 (s, 2H), 5.41 (s, 2H), 5.34-5.23 (m, 3H), 5.08 (s, 2H), 4.40-4.33 (m, 1H), 4.19 (dd, J = 8.5, 6.7 Hz, 1H), 3.30-3.06 (m, 2H), 3.05-2.84 (m, 4H), 2.37 (s, 3H), 2.24-2.08 (m, 4H), 2.03-1.80 (m, 3H), 1.74-1.31 (m, 17H), 1.21-1.18 (m, 2H), 0.89-0.82 (m, 9H). MS (ESI) m / z: 1054.5 [M+H] +

[0272] Step 3: Synthesis of H-Ahx-Val-Cit-PAB-Exatecan Trifluoroacetate 100 mg of Boc-Ahx-Val-Cit-PAB-Exatecan was dissolved in 3 mL of DCM, and 0.3 mL of trifluoroacetic acid was added and stirred at room temperature for 4 hours. The reaction solution was evaporated under reduced pressure using an evaporator, and then purified by reverse phase chromatography (0.1% TFA aqueous solution / MeCN = 100 / 0 → 60 / 40) using an ODS column to obtain 63.7 mg of H-Ahx-Val-Cit-PAB-Exatecan Trifluoroacetate.

[0273]

[0274] MS (ESI) m / z: 954.5 [M+H] +

[0275] Step 4: Synthesis of Exatecan-PAB-Cit-Val-Ahx-linked copolymer 100 mg of the copolymer obtained by the same method as in Example 72 was dissolved in 1 mL of DMF, and 25.4 mg of H-Ahx-Val-Cit-PAB-Exatecan Trifluoroacetate, 15.5 μL of N,N-Diisopropylethylamine, and 11.3 mg of HATU were added, followed by stirring at room temperature overnight. The reaction solution was purified by dialysis (dialysis membrane: Spectra / Por Regenerated Cellulose Membrane 6, molecular cut-off: 3.5 kDa, external solution: methanol), and the solvent was removed by distillation under reduced pressure and vacuum drying to recover the copolymer, yielding 106 mg of Exatecan-PAB-Cit-Val-Ahx linked copolymer. The Z-average particle size and polydispersity index of the resulting copolymer in water were measured by dynamic light scattering (DLS) and found to be 8.5 nm (polydispersity index: 0.129).

[0276]

[0277] The Exatecan-PAB-Cit-Val-Ahx linked copolymer was measured using NMR. 1The number of Exatecan molecules introduced per copolymer molecule was analyzed by H-NMR spectroscopy and found to be 9.4 mol / mol. [Measurement equipment and conditions] (1) 1 H-NMR measurement Apparatus: JNM-ECX400 (400 MHz) / JEOL Solvent: Dimethyl sulfoxide-d containing 0.03% tetramethylsilane / Kanto Chemical Sample concentration: 20 mg / mL Measurement temperature: 25°C Number of accumulations: 399 Results: Figure 21

[0278] [Examples 159 to 163] The copolymer obtained in Example 158 was synthesized by appropriately changing the charged amounts and using the same method as in Example 132. In addition, the copolymers obtained in the same manner as in Examples 72, 79, 82, and 84 were synthesized sequentially by the same production methods as in Examples 94, 96, and 132 while appropriately changing the charged amounts.

[0279]

[0280] Comparative Example 1 Preparation of Oxaliplatin Solution Elplat TM 1 mL of 50 mg of intravenous infusion solution (Yakult Honsha Co., Ltd.) was added to 5.58 mL of 5.9 (w / v) % glucose solution to prepare a 5 (w / v) % glucose solution containing 760 μg of oxaliplatin.

[0281] Comparative Example 2 Preparation of Cetuximab Solution Cetuximab (Erbitux) TM 100 mg of cetuximab injection (Merck Biopharmaceutical Co., Ltd.) was diluted with saline (Otsuka saline) to prepare a 2 mg / mL solution, which was then administered intravenously (10 mg / kg body dose). Similarly, the cetuximab was diluted with RPMI 1640 medium containing 10% fetal bovine serum (Merck KGaA) to evaluate its anti-cellular effect at final concentrations of 66 nmol / L, 20 nmol / L, 6.6 nmol / L, 2.0 nmol / L, 0.66 nmol / L, 0.20 nmol / L, 0.066 nmol / L, or 0.020 nmol / L.

[0282] Comparative Example 3 Preparation of Trastuzumab Solution Trastuzumab (Herceptin TM A 20 mg / mL solution was prepared by dissolving 60 mg of trastuzumab (60 mg for injection, Chugai Pharmaceutical Co., Ltd.) in 3.0 mL of Japanese Pharmacopoeia water for injection. This solution was then diluted with RPMI 1640 medium to achieve final trastuzumab concentrations of 20 nmol / L, 6.8 nmol / L, 2.0 nmol / L, 0.68 nmol / L, 0.20 nmol / L, 0.068 nmol / L, 0.020 nmol / L, 0.0068 nmol / L, or 0.0020 nmol / L. The anticellular effects were evaluated.

[0283] Comparative Example 4 Preparation of Rituximab Solution Rituximab (Rituxan TM Rituximab (100 mg for intravenous infusion, Zenyaku Kogyo Co., Ltd.) was diluted with RPMI 1640 medium to give final concentrations of 69 nmol / L, 21 nmol / L, 6.9 nmol / L, 2.1 nmol / L, 0.69 nmol / L, 0.21 nmol / L, 0.069 nmol / L, or 0.021 nmol / L, and the anticellular effects were evaluated.

[0284] Test Example 1: Drug Efficacy Test A tumor-bearing model in which mouse colon cancer cell line C26 (American Type Culture Collection) was subcutaneously transplanted into female nude mice (BALB / c-nu / nu, 7 weeks old; Charles River Japan, Inc.) was used for the drug efficacy test. Mouse colon cancer cell line C26, which had been subcultured in a CO2 incubator, was suspended in liquid medium (Dulbecco's Modified Eagle's Medium-high glucose, Sigma-Aldrich) and the number of cells per mouse was 1 x 10 6 The nude mice were then bred for about one week, after which the average tumor volume was about 30 mm 3Drug administration was initiated when the tumors reached a maturity of 100 mg / kg. DACHPt-encapsulated SCNP (DACHPt-encapsulated SCNP prepared using the copolymer of Example 70) was administered intravenously to the tail vein (3 times every other day), and the antitumor effect was evaluated based on tumor volume (4-5 mice per group). For comparison, oxaliplatin solution (Comparative Example 1) was administered in the same manner. The dosage of each formulation was 8 mg / kg (3.9 mg / kg in Pt equivalent) as the maximum administrable dose for the oxaliplatin solution, and 3 mg / kg in Pt equivalent for the DACHPt-encapsulated SCNP. The change in tumor volume over time is shown in Figure 22. For DACHPt-encapsulated SCNP, T / C = 0.4 after 14 days of administration [T / C: tumor volume ratio between the drug-administered group (T) and the control group (C)]. For oxaliplatin solution (Comparative Example 1), T / C = 1.1 after 14 days of administration. Furthermore, it was confirmed that DACHPt-encapsulated SCNP significantly inhibited tumor growth compared to the control 14 days after administration (student's t-test).These results indicate that DACHPt-encapsulated SCNP has a superior antitumor effect compared to oxaliplatin solution.

[0285] Test Example 2 Anti-Cell Test EGFR antigen-positive human breast cancer cell line MDA-MB-468 (American Type Culture Collection) and EGFR antigen-negative human breast cancer cell line MDA-MB-453 (RIKEN BRC CELL BANK) were cultured in RPMI 1640 medium at a concentration of 2.0 × 10 4 cells / mL and 4.0 x 10 4 The solution was adjusted to a concentration of 100 μL / mL, and 100 μL of each was added to a 96-well cell culture microplate and cultured overnight. The next day, 100 μL of each evaluation sample diluted with RPMI medium was added to the microplate and cultured at 37°C under 5% CO2 for 4 days. After the culture, CellTiter-Glo was added to the microplate. TM Luminescent Cell Viability Assay (Promega Corporation) was added and stirred, and the mixture was left to stand at room temperature for 10 minutes, after which the luminescence intensity was measured using a plate reader (Molecular Devices, LLC.). The cell viability was calculated using the following formula:

[0286] Cell viability (%) = a ÷ b × 100 (where a is the average luminescence intensity of the sample wells (n = 3), and b is the average luminescence intensity of the wells to which no sample was added (n = 3)). IC is the drug concentration at which the cell viability becomes 50%. 50 Values ​​are SAS TM Calculations were performed using 9.4 Software (SAS Institute Japan Ltd.).

[0287]

[0288] Test Example 3 Anti-Cell Test HER2 antigen-positive human gastric cancer cell line NCI-N87 (American Type Culture Collection) or HER2 antigen-negative human breast cancer cell line MDA-MB-468 were cultured in RPMI 1640 medium at a concentration of 2.0 × 10 4 The solution was adjusted to a concentration of 100 μL / mL, and 100 μL of each was added to a 96-well cell culture microplate and cultured overnight. The next day, 100 μL of each evaluation sample diluted with RPMI medium was added to the microplate and cultured at 37°C under 5% CO2 for 4 days. After the culture, CellTiter-Glo was added to the microplate. TM Luminescent Cell Viability Assay (Promega Corporation) was added and stirred, and the mixture was left to stand at room temperature for 10 minutes, after which the amount of luminescence was measured using a plate reader (Molecular Devices, LLC.). Cell viability and IC 50 The value was calculated.

[0289] [Test Example 4] Anti-cell test CD20 antigen-positive human B-cell lymphoma-derived Raji cells or CD20 antigen-negative human T-lymphoblastic leukemia-derived MOLT-4 cells were cultured in RPMI 1640 medium at a concentration of 5.0 × 10 4 The solution was adjusted to a concentration of 1000 cells / mL, and 50 μL of each was added to a 96-well cell culture microplate and cultured overnight. The next day, 50 μL of the evaluation sample diluted with RPMI medium was added to the microplate and cultured at 37°C under 5% CO2 for 4 days. After the culture, CellTiter-Glo was added to the microplate. TMLuminescent Cell Viability Assay (Promega Corporation) was added and stirred, and the mixture was left to stand at room temperature for 10 minutes, after which the amount of luminescence was measured using a plate reader (Molecular Devices, LLC.). Cell viability and IC 50 The value was calculated.

[0290] Test Example 5: Antitumor Effect Confirmation Test EGFR-positive human colon cancer cell line HT-29 was suspended in PBS and diluted to 2.5 × 10 7 The concentration was adjusted to 5 × 10 cells / mL. 6 Cells (0.2 mL) were subcutaneously implanted into the right flank of nude mice (female, 6 weeks old) after quarantine. Eight days after cell subcutaneous implantation, mice were randomly assigned to groups (12 mice per group). Cetuximab-conjugated micellar-drug conjugate (Example 138, DAR = 38) was administered intravenously at doses of 1.8 and 5.5 mg / kg (1.0 and 3.0 mg antibody / kg in terms of the antibody moiety, and 0.18 and 0.55 mg DM1 / kg in terms of the DM1 moiety), or DM1-conjugated micelles (Example 120, unbound antibody) were administered intravenously at a dose of 2.5 mg / kg (0.55 mg DM1 / kg in terms of the DM1 moiety). A saline-administered group served as a control group. The results are shown in Figure 23. The samples evaluated demonstrated dose-dependent antitumor effects. No weight loss was observed in mice following administration.

[0291] Test Example 6: Antitumor Effect Confirmation Test HER2-positive human gastric cancer cell line NCI-N87 was suspended in PBS and 5 × 10 7 The concentration was adjusted to 1 × 10 cells / mL. 7Nude mice (female, 6 weeks old; Charles River Japan, Inc.) were subcutaneously implanted with 0.2 mL of trastuzumab-conjugated micelle-drug conjugates into the right flank. Seven days after subcutaneous cell implantation, the mice were randomly assigned to groups (12 mice per group). Trastuzumab-conjugated micelle-drug conjugates (Example 151, DAR = 40) were administered at doses of 1.9 and 5.7 mg / kg (1.0 and 3.0 mg antibody / kg in terms of the antibody moiety, and 0.20 and 0.60 mg DM1 / kg in terms of the DM1 moiety), or DM1-conjugated micelles (Example 120, unbound antibody) were administered at a dose of 0.70 mg / kg (0.20 mg DM1 / kg in terms of the DM1 moiety) into the tail vein. A saline-administered group served as a control. The results are shown in Figure 24. The samples evaluated demonstrated dose-dependent antitumor effects. Furthermore, no weight loss was observed in the mice due to the administration.

[0292] Test Example 7: Antitumor effect confirmation test EGFR-positive human breast cancer cell line MDA-MB-468 was suspended in PBS and 5 × 10 7 The concentration was adjusted to 1 × 10 cells / mL. 7 Nude mice (female, 6 weeks old; Jackson Laboratory Japan, Inc.) were subcutaneously transplanted with the cells (0.2 mL) into the right flank. Twenty-seven days after subcutaneous cell transplantation, mice were randomly assigned to groups (10 mice per group). Cetuximab-conjugated micelle-drug conjugate (Example 160, DAR = 25) was administered at a dose of 3.0 mg / kg (1.6 mg antibody / kg dose as the antibody moiety, 0.20 mg DM1 / kg dose as the DM1 moiety) or cetuximab-conjugated micelle-drug conjugate (Example 161, DAR = 41) was administered at a dose of 1.8 mg / kg (1.0 mg antibody / kg dose as the antibody moiety, 0.20 mg DM1 / kg dose as the DM1 moiety) via the tail vein. A saline-administered group served as a control. The results are shown in Figure 25. The evaluated samples showed antitumor effects, and no weight loss was observed in the mice following administration.

[0293] Test Example 8: Antitumor Effect Confirmation Test EGFR-positive human colon cancer cell line HCT-116 carrying a KRAS mutation (G13D) was suspended in PBS and diluted to 5 × 107 The concentration was adjusted to 1 × 10 cells / mL. 7 Nude mice (female, 6 weeks old; Jackson Laboratory Japan, Inc.) were subcutaneously transplanted with the cells (0.2 mL) into the right flank. Seven days after subcutaneous cell transplantation, mice were randomly assigned to groups (10 mice per group). Cetuximab-conjugated micelle-drug conjugate (Example 162, DAR = 20) was administered at a dose of 5.5 mg / kg (3.1 mg antibody / kg dose as the antibody moiety, 0.30 mg DM1 / kg dose as the DM1 moiety) or cetuximab-conjugated micelle-drug conjugate (Example 163, DAR = 43) was administered at a dose of 2.6 mg / kg (1.4 mg antibody / kg dose as the antibody moiety, 0.30 mg DM1 / kg dose as the DM1 moiety) into the tail vein. A saline-administered group served as a control group. The results are shown in Figure 26. The evaluated samples showed antitumor effects, and no weight loss was observed in the mice following administration.

[0294] The major and minor axes of the tumor were measured twice a week using a digital caliper (product number 19975, Shinwa Measuring Co., Ltd.), and the tumor volume was calculated using the following formula.

[0295] Tumor volume (mm 3 ) = a × b 2 / 2 [wherein a represents the major axis (mm), and b represents the minor axis (mm)]

Claims

1. A drug conjugate comprising a random copolymer X having structural units represented by the following formulae (A), (B) and (C), to which a target recognition molecule is bound, and a drug (excluding the target recognition molecule). 【Chemistry 1】 [In the formula, R 1 , R 2 and R 3 are the same or different and are hydrogen atoms or C 1-3 represents an alkyl group, and R 4 is C 1-3 represents an alkyl group, and R 5 is a hydrogen atom, C 1-18 an alkyl group, a 3- to 8-membered cycloalkyl group which may have a substituent, an adamantyl group, a C 6-18 represents an aryl group or an optionally substituted 5- to 10-membered heteroaryl group; X 1 , X 2 and X 3 are the same or different and are an oxygen atom, a sulfur atom, or an N-R 7 indicates R 6 represents a linker, where the linker is a group that can crosslink when the structural unit (C) is bound to a drug, and R 7 is a hydrogen atom or C 1-3 represents an alkyl group, m represents an integer of 1 to 100, and n represents an integer of 0 to 3.

2. R 6 The linker is represented by the following formula (5): 【Chemistry 2】 [In the formula, R 8 indicates a drug, and Ak 1 is C 1-7 represents an alkylene bond, and X 4 is an oxygen atom, a sulfur atom, or —N(R 7 )-(R 7 is a hydrogen atom or C 1-3 (represents an alkyl group)] The drug conjugate according to claim 1, wherein the group is represented by the formula:

3. 2. The drug conjugate according to claim 1, wherein the ratio of the structural units (A), (B), and (C) is 0.01 to 100 parts by mass of (B) and 0.1 to 100 parts by mass of (C) per part by mass of (A).

4. 2. The drug conjugate according to claim 1, having a number average molecular weight of 5,000 to 150,000.

5. The drug conjugate of claim 1 , wherein the target recognition molecule is an antibody.

6. The drug conjugate according to claim 5, wherein the antibody is an anti-EGFR antibody, an anti-Her2 antibody, an anti-CD20 antibody, an anti-CD276 antibody, an anti-MUC1 antibody, an anti-PD-L1 antibody, or an anti-TROP-2 antibody.

7. The drug conjugate of claim 5, wherein the antibody is cetuximab, panitumumab, necitumumab, amivantamab, trastuzumab, pertuzumab, margetuximab, rituximab, ibritumomab, tositumomab, ofatumumab, obinutuzumab, clivatuzumab, gatipotuzumab, ifinatamab, mirzotamab, vobramitamab, atezolizumab, avelumab, durvalumab, sacituzumab, or a functional fragment thereof.

8. The drug conjugate described in claim 1, wherein the drug is an anticancer drug.

9. 2. The drug conjugate of claim 1, wherein the drug is an antimetabolite, an alkylating agent, an anthracycline, an antibiotic, a mitotic inhibitor, a topoisomerase inhibitor, a proteasome inhibitor, or an antihormonal agent.

10. 2. The drug conjugate of claim 1, wherein the drug is DM0, DM1, DM2, DM3, DM4, emtansine, auristatin E, auristatin phenylalanine phenylenediamine (AFP), monomethyl auristatin E, monomethyl auristatin D, monomethyl auristatin F, paclitaxel, docetaxel, irinotecan, topotecan, nogitecan, amsacrine, etoposide, teniposide, mizanthrone, SN-38, exatecan, or deruxtecan.

11. The drug conjugate according to any one of claims 1 and 8 to 10, wherein the bond between the target recognition molecule or the drug and the copolymer X is a covalent bond or a non-covalent bond.

12. The bond between the target recognition molecule or drug and the copolymer X is represented by the following formula (a): 【Transformation 3】 [In the formula, J 1 is a target recognition molecule or a binding site for a drug, and J 2 is the bond to the copolymer X, and Ak 2 , Ak 3 are each independently a single bond or C 1-7 represents an alkylene bond, and B 1 , B 2 each independently represents a single bond, an amide bond, or an ester bond; L 1 is a single bond, -(CH 2 CH 2 O) o CH 2 CH 2 -, phenylene, cyclohexylene, -NH-peptide-CO-, or phenylene-NH-peptide-CO-, and o represents an integer of 0 to 100. The drug conjugate according to any one of claims 1 and 8 to 10,

13. A single chain nanoparticle comprising the drug conjugate of claim 1 or 8.

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