CN117180449A

CN117180449A - Preparation method of antibody drug conjugate

Info

Publication number: CN117180449A
Application number: CN202311458310.3A
Authority: CN
Inventors: 秦宇; 刘金坡; 李盈淳; 吴纲; 徐佳伟; 陈梅梅; 刘翔; 张永波; 王晓伟
Original assignee: Chia Tai Tianqing Pharmaceutical Group Co Ltd; Nanjing Shunxin Pharmaceutical Co Ltd
Current assignee: Chia Tai Tianqing Pharmaceutical Group Co Ltd; Nanjing Shunxin Pharmaceutical Co Ltd
Priority date: 2023-11-03
Filing date: 2023-11-03
Publication date: 2023-12-08
Anticipated expiration: 2043-11-03
Also published as: CN117180449B

Abstract

Belongs to the field of biotechnology, and relates to a preparation method of an antibody drug conjugate, which comprises the following steps: (i) Reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer system to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof; (ii) Reacting the linker-payload with the thiol-bearing antibody or antigen-binding fragment thereof obtained in step (i); wherein the reaction temperature in step (i) is greater than 10 ℃.

Description

Preparation method of antibody drug conjugate

Technical Field

The disclosure belongs to the field of biotechnology, and relates to a preparation method of an antibody drug conjugate and the antibody drug conjugate prepared by the preparation method.

Background

Antibody Drug Conjugates (ADCs) are a class of drugs that combine the high specificity of therapeutic antibodies and the high killing activity of cytotoxic drugs, where the therapeutic Antibody moiety and the cytotoxic Drug moiety are linked by an intermediate linker moiety. Compared with the traditional chemotherapy drugs, the antibody drug conjugate can accurately bind tumor cells and reduce the influence on normal cells. At present, since the first antibody drug conjugate Mylotarg was marketed in the united states in 2000, at least ten ADCs have been introduced to the market worldwide, and many new antibody drug conjugates have been reported in the anti-tumor field.

Antibodies typically have four interchain disulfide bonds, which can act as binding sites for the antibody to the linker-payload. Methods for producing DAR4 antibody drug conjugates are known, however, some methods of conjugation often result in high heterogeneity of antibody drug conjugates, low D4 content, and other methods have harsh reaction conditions, the presence of toxic reagents, etc., and thus, there is still a need to develop new methods of conjugation of antibodies to cytotoxic drugs.

Disclosure of Invention

Preparation method

The present disclosure provides a method of preparing an antibody drug conjugate comprising:

(i) Reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof;

(ii) Reacting the linker-payload with the thiol-bearing antibody or antigen-binding fragment thereof obtained in step (i);

wherein,

the reaction temperature in step (i) is greater than 10 ℃.

In some embodiments, the reaction temperature in step (i) is from 10.5 ℃ to 20 ℃. In some embodiments, the reaction temperature in step (i) is from 10.5 ℃ to 15 ℃. In some embodiments, the reaction temperature in step (i) is from 10.5 ℃ to 14 ℃. In some embodiments, the reaction temperature in step (i) is from 10.5 ℃ to 11 ℃, 11 ℃ to 14 ℃, or 11 ℃ to 13 ℃. In some embodiments, the reaction temperature in step (i) is 10.5 ℃, 11 ℃, 11.5 ℃, 12 ℃, 12.5 ℃, 13 ℃, 13.5 ℃, 14 ℃, 14.5 ℃, 15 ℃, or a range formed of any of the above values.

In some embodiments, the ratio of the amount of reducing agent to the substance of the antibody or antigen binding fragment thereof is from 1:1 to 4:1. In some embodiments, the ratio of the amount of reducing agent to the substance of the antibody or antigen binding fragment thereof is from 2:1 to 3:1. In some embodiments, the ratio of the amount of reducing agent to the substance of the antibody or antigen binding fragment thereof is from 2.4:1 to 2.5:1. In some embodiments, the ratio of the amount of the reducing agent to the substance of the antibody or antigen binding fragment thereof is 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, or a range formed by any of the above values.

In some embodiments, the reducing agent may be tris (2-carboxyethyl) phosphine (TCEP) or a salt thereof, dithiothreitol, or 2-mercaptoethanol. In some embodiments the reducing agent is tris (2-carboxyethyl) phosphine or a salt thereof, preferably tris (2-carboxyethyl) phosphine hydrochloride (tcep·hcl).

In some embodiments, the buffer may be HEPES (4- (2-hydroxyethyl) -1-piperazine ethanesulfonic acid) buffer, histidine buffer, phosphate buffer, borate buffer, or acetate buffer. In some embodiments, the buffer is a histidine buffer. In some embodiments, the buffer is a histidine-hcl buffer. In some embodiments, the concentration of the buffer is from 1 mM to 30 mM, e.g., 5 mM, 10 mM, 15 mM, 20 mM, 25 mM, or 30 mM, preferably 20 mM.

In some embodiments, the time of the reaction in step (i) is from 1 to 10 hours. In some embodiments, the time of the reaction in step (i) is from 1 to 5 hours. In some embodiments, the time of the reaction in step (i) is 2 to 4 hours. In some embodiments, the time of the reaction in step (i) is 2 to 3 hours. In some embodiments, the time of the reaction in step (i) is 2.5 to 3 hours. In some embodiments, the time of the reaction in step (i) is 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, 3 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours, 3.5 hours, 3.6 hours, 3.7 hours, 3.8 hours, 3.9 hours, 4 hours, or a range formed by any of the above.

In some embodiments, the pH of the reaction in step (i) is from 5 to 9. In some embodiments, the pH of the reaction in step (i) is from 6 to 8. In some embodiments, the pH of the reaction in step (i) is from 6.5 to 7.5. In some embodiments, the pH of the reaction in step (i) is from 6.9 to 7.2. In some embodiments, the pH of the reaction in step (i) is 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, or a range formed by any of the above values.

In some embodiments, sucrose is further added to the buffer. In some embodiments, the sucrose is at a concentration of 1% to 10% (w/v) in the buffer. In some embodiments, the sucrose is at a concentration of 1% (w/v), 2% (w/v), 3% (w/v), 4% (w/v), 5% (w/v), 6% (w/v), 7% (w/v), 8% (w/v), 9% (w/v), or 10% (w/v), preferably 5% (w/v) in the buffer.

In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is from 2:1 to 10:1. In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is from 3:1 to 7:1. In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is from 4:1 to 6:1. In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is from 4.5:1 to 5.5:1. In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is from 4.7:1 to 4.8:1. In some embodiments, the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is 4.5:1, 4.6:1, 4.7:1, 4.8:1, 4.9:1, 5:1, 5.1:1, 5.2:1, 5.3:1, 5.4:1, 5.5:1, or a range formed by any of the above values.

In some embodiments, for step (ii), more specifically, the solution containing the linker-payload is added to a buffer comprising the antibody or antigen-binding fragment thereof having a thiol group obtained in step (i), such that the linker-payload can react with the antibody or antigen-binding fragment thereof.

In some embodiments, examples of the solvent for dissolving the linker-payload in the solution containing the linker-payload include an organic solvent, which may be an aqueous acetone solution (e.g., 50% aqueous acetone solution), an aqueous ethanol solution (e.g., 80% aqueous ethanol solution), an aqueous methanol solution (e.g., 80% aqueous methanol solution), an aqueous isopropanol solution (e.g., 80% aqueous isopropanol solution), an aqueous dimethyl sulfoxide solution (e.g., 80% aqueous dimethyl sulfoxide solution), acetone, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), or N-methyl-2-pyrrolidone (NMP). In some embodiments, the organic solvent as solvent is an aqueous acetone solution, preferably a 50% aqueous acetone solution. In some embodiments, the organic solvent as solvent is acetone. In some embodiments, the organic solvent as solvent is an aqueous DMSO solution or DMSO, preferably DMSO.

In some embodiments, the reaction temperature in step (ii) is from 10.5 ℃ to 20 ℃. In some embodiments, the reaction temperature in step (ii) is from 10.5 ℃ to 15 ℃. In some embodiments, the reaction temperature in step (ii) is from 10.5 ℃ to 14 ℃. In some embodiments, the reaction temperature in step (ii) is from 10.5 ℃ to 11 ℃, 11 ℃ to 14 ℃, or 11 ℃ to 13 ℃. In some embodiments, the reaction temperature in step (ii) is 10.5 ℃, 11 ℃, 11.5 ℃, 12 ℃, 12.5 ℃, 13 ℃, 13.5 ℃, 14 ℃, 14.5 ℃, 15 ℃, or a range formed of any of the above values.

In some embodiments, the time of the reaction in step (ii) is from 1 to 10 hours. In some embodiments, the time of the reaction in step (ii) is from 1 to 5 hours. In some embodiments, the time of the reaction in step (ii) is 2 to 4 hours. In some embodiments, the time of the reaction in step (ii) is 2 to 3 hours. In some embodiments, the time of the reaction in step (ii) is 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, 3 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours, 3.5 hours, 3.6 hours, 3.7 hours, 3.8 hours, 3.9 hours, 4 hours, or a range formed by any of the above.

In some embodiments, the reaction in step (ii) may be terminated by inactivating the unreacted linker-payload with a thiol-containing reagent. In some embodiments, the thiol-containing agent may be cysteine or N-acetylcysteine, preferably N-acetylcysteine. In some specific embodiments, the reaction in step (ii) may be terminated by: n-acetylcysteine is added to the reaction system containing the linker-payload and reacted for 10 to 40 minutes, preferably 25 to 40 minutes. In some embodiments, the ratio of the amount of N-acetylcysteine to the substance of the antibody or antigen binding fragment thereof is from 1:1 to 8:1, preferably 4:1.

In some embodiments, in step (ii), the organic solvent is added to the buffer comprising the thiol-bearing antibody or antigen-binding fragment thereof obtained in step (i) and the concentration of the organic solvent is brought to 1% to 10% (v/v), preferably 2% to 5% (v/v), before the addition of the solution containing the linker-payload. In some embodiments, the concentration of the organic solvent is 1% (v/v), 2% (v/v), 3% (v/v), 4% (v/v), 5% (v/v), 6% (v/v), 7% (v/v), 8% (v/v), 9% (v/v), or 10% (v/v). In some embodiments, the organic solvent may be acetone, ethanol, methanol, isopropanol, DMSO, DMF, DMA, or NMP, preferably acetone or DMSO.

The reaction in step (ii) may couple the linker-payload to the antibody or antigen binding fragment thereof, thereby producing an antibody drug conjugate. After the completion of the coupling, the antibody drug conjugate is separated and purified from the system, and for example, separation and purification can be performed using a commercially available ultrafiltration membrane or the like. As this ultrafiltration membrane, a suitable ultrafiltration membrane may be used, for example, an ultrafiltration membrane having a molecular weight of 1 kDa to 100 kDa, preferably an ultrafiltration membrane having a molecular weight of 30 kDa.

In some specific embodiments, the method of making comprises:

(i) Reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof, wherein the reducing agent is tris (2-carboxyethyl) phosphine hydrochloride;

(ii) Reacting a linker-payload with the thiol-bearing antibody or antigen-binding fragment thereof obtained in step (i), wherein the linker-payload is

；

Wherein,

the reaction temperature in step (i) is 10.5 ℃ to 14 ℃, and the reaction time in step (i) is 2 to 3 hours;

and the DAR value of the prepared antibody drug conjugate is 3.5-4.5.

In some specific embodiments, the method of making comprises:

(i) Reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof, wherein the reducing agent is tris (2-carboxyethyl) phosphine hydrochloride, the buffer is a histidine buffer, and preferably sucrose is further added to the buffer; preferably, the antibody or antigen-binding fragment thereof is an anti-TROP-2 antibody or antigen-binding fragment thereof;

；

Wherein,

the reaction temperature in step (i) is from 10.5 ℃ to 14 ℃, the time of reaction in step (i) is from 2 to 3 hours, and the ratio of the amount of reducing agent to the substance of the antibody or antigen binding fragment thereof in step (i) is from 2:1 to 3:1, preferably 2.5:1;

the ratio of the amount of linker-payload to the substance of the antibody or antigen binding fragment thereof in step (ii) is 4.5:1 to 5.5:1, preferably 4.8:1, the reaction temperature in step (ii) is 10.5 ℃ to 14 ℃, the time of reaction in step (ii) is 2 to 4 hours, acetone or DMSO is added to the buffer comprising the thiol-bearing antibody or antigen binding fragment thereof obtained in step (i) and the concentration of the organic solvent is 2% to 5% (v/v), preferably 5% (v/v) before the addition of the solution comprising the linker-payload in step (ii); and is also provided with

The DAR value of the prepared antibody drug conjugate is 3.5-4.5, wherein the content of D4 is 55% or more, preferably 60% or more.

The preparation method disclosed by the invention has the advantages of mild reaction conditions, low cost and easiness in operation.

The Linker-payload (Linker-payload) is formed by the attachment of a cytotoxic drug to the Linker. The number of cytotoxic drugs to which the antibodies or antigen binding fragments thereof are linked may vary such that the antibody drug conjugate may be homogeneous or heterogeneous, i.e., the antibody drug conjugate comprises antibodies or antigen binding fragments thereof linked to different amounts of cytotoxic drugs, e.g., 1 molecule of antibody or antigen binding fragment thereof linked to 0 (i.e., no cytotoxic drug), 1, 2, 3, 4, 5, 6, 7, 8, or other more molecules of cytotoxic drug. Antibody drug conjugates in which 1 molecule of antibody or antigen binding fragment thereof is linked to 0, 1, 2, 3, 4, 5, 6, 7 or 8 molecules of cytotoxic drug are referred to as D0, D1, D2, D3, D4, D5, D6, D7, D8, respectively.

By controlling the ratio of antibodies or antigen binding fragments thereof linked to different amounts of cytotoxic drug as described above, antibody drug conjugates with different drug-to-antibody ratios (DARs) can be produced. "DAR" is used interchangeably herein with "n". It is understood that the DAR or n is the average number of cytotoxic drug links per molecule of antibody or antigen binding fragment thereof in an antibody drug conjugate. For example, "DAR of 4" refers to an antibody drug conjugate comprising a heterogeneous mixture of the same or different number of cytotoxic drugs attached per antibody or antigen binding fragment molecule thereof (e.g., 0, 1, 2, 3, 4, 5, 6, 7, and/or 8 cytotoxic drugs attached per antibody or antigen binding fragment thereof), but an average number of cytotoxic drug attachments per antibody or antigen binding fragment thereof of 4. Similarly, "DAR of 8" means that the average number of cytotoxic drug linkages per molecule of antibody or antigen binding fragment thereof in the antibody drug conjugate is 8.

D8 is excellent in therapeutic (e.g., antitumor) effect, but causes problems in safety such as toxicity in some cases. Thus, to improve safety, there are cases where antibody drug conjugates with DAR values less than 8 (e.g., DAR of 4) are used while maintaining therapeutic efficacy. Antibody drug conjugates typically consist of one or more of D0, D1, D2, D3, D4, D5, D6, D7, D8. Thus, there may be cases where even though different antibody drug conjugates have the same DAR value as each other, their efficacy and/or toxicity differ from each other if the distribution of the number of cytotoxic drugs they are linked to is different. That is, an antibody drug conjugate with higher D0 and D8 content of DAR 4 may have reduced therapeutic effects and may exhibit strong toxicity compared to an antibody drug conjugate with higher D4 content. Antibody drug conjugates produced by the methods of preparation of the present disclosure have a DAR value of 3-5, or 3.5-4.5. In some embodiments, an antibody drug conjugate produced by the methods of preparation of the present disclosure has a DAR value of 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5. In some embodiments, the content of D4 in the antibody drug conjugate produced by the methods of preparation of the present disclosure is in the range of 50% or more, 55% or more, 60% or more, or 65% or more, or 50% to 90%, 50% to 80%, 50% to 70%, 50% to 60%, 60% to 70%, or 55% to 65%. In some embodiments, the content of D4 in the antibody drug conjugate produced by the methods of preparation of the present disclosure is 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, or 65%. In some embodiments, the content of D8 in the antibody drug conjugate produced by the methods of preparation of the present disclosure is 5% or less, 2% or less, or 1% or less, or 0%. Thus, the antibody drug conjugate produced by the preparation method of the present disclosure has excellent safety.

In some embodiments, the antibody drug conjugate produced by the methods of preparation of the present disclosure has the structure shown in formula I below:

I，

wherein Ab is an antibody or antigen binding fragment thereof, n is selected from 3-5, R ¹ Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl, R ² Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl; alternatively, R ¹ And R is ² Together with the atoms to which they are attached form an optionally substituted 5-to 8-membered heterocyclic group; and, the 3-position of- (succinimid-3-yl-N) -in formula I is linked to Ab. In some embodiments, the R ¹ And R is ² Each independently selected from hydrogen atoms or C _1-5 Alkyl (preferably C _1-4 Alkyl radicals, e.g. C _1-3 Alkyl). In some embodiments, the R ¹ And R is ² Each independently selected from hydrogen atom, methyl, ethyl, propyl or isopropyl. In some embodiments, the R ¹ And R is ² Is a hydrogen atom. In some embodiments, the 3-position of- (succinimid-3-yl-N) -in the structure shown in formula I is linked to a thiol group after reduction of the Ab disulfide bond. In some embodiments, n is 3.5 to 4.5. In some embodiments, the n is 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5.

In some specific embodiments, the structure of the antibody drug conjugate produced by the methods of preparation of the present disclosure is shown in formula I-1 below.

I-1，

Wherein Ab is an antibody or antigen binding fragment thereof and n is selected from 3-5. In some embodiments, the 3-position of- (succinimid-3-yl-N) -in the structure of formula I-1 is linked to a thiol group after reduction of the Ab disulfide bond. In some embodiments, n is 3.5 to 4.5. In some embodiments, the n is 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5.

Antibodies or antigen binding fragments thereof

Antibodies or antigen-binding fragments thereof useful in the present disclosure include, but are not limited to, monoclonal antibodies, monospecific antibodies, bispecific antibodies, multispecific antibodies, nanobodies, or antigen-binding fragments of the foregoing antibodies, including, but not limited to, fab fragments, F (ab') ₂ Fragments, fd fragments, fv fragments, dAbs, single chain Fv (scFv) molecules, single chain Fab (scFab), V _H H. The antibody or antigen binding fragment thereof may be of any of IgG, igE, igM, igD or IgA (class), preferably IgG. The antibody or antigen-binding fragment thereof may be any subclass (subclass) of IgG1, igG2, igG3, igG4, igA1, or IgA2, and preferably IgG1 or IgG4. The antibody or antigen binding fragment thereof may be derived from any species including, but not limited to, human, rat, mouse, and rabbit; when derived from sources other than humans In the case of species, it is preferable to chimeric or humanize the species by using a known technique. In some embodiments, the antibody or antigen binding fragment thereof is a murine antibody, chimeric antibody, humanized antibody, or human antibody. The antibody or antigen binding fragment thereof may bind to any disease-associated antigen known in the art. When the disease is a tumor, the antigen may be selected from any tumor associated antigen including, but not limited to, HER2, HER3, EGFR, ROR1, CLDN18.2, B7-H3, TROP-2, CD20, CD22, CD30, CD33, CD47, CD56, CD70, CD79B, VEGF, VEGFR, MUC1, c-MET, RET, LIV-1, PD-1 or PD-L1. In some embodiments, the antibody or antigen-binding fragment thereof is an anti-HER 2 antibody or antigen-binding fragment thereof, an anti-HER 3 antibody or antigen-binding fragment thereof, an anti-EGFR antibody or antigen-binding fragment thereof, an anti-ROR 1 antibody or antigen-binding fragment thereof, an anti-CLDN 18.2 antibody or antigen-binding fragment thereof, an anti-B7-H3 antibody or antigen-binding fragment thereof, an anti-TROP-2 antibody or antigen-binding fragment thereof, an anti-CD 20 antibody or antigen-binding fragment thereof, an anti-CD 22 antibody or antigen-binding fragment thereof, an anti-CD 30 antibody or antigen-binding fragment thereof, an anti-CD 33 antibody or antigen-binding fragment thereof, an anti-CD 47 antibody or antigen-binding fragment thereof, an anti-CD 56 antibody or antigen-binding fragment thereof, an anti-CD 70 antibody or antigen-binding fragment thereof, an anti-CD 79B antibody or antigen-binding fragment thereof, an anti-VEGF antibody or antigen-binding fragment thereof, an anti-VEGFR antibody or antigen-binding fragment thereof, an anti-MUC 1 antibody or antigen-binding fragment thereof, an anti-MET antibody or antigen-binding fragment thereof, an anti-RET antibody or antigen-binding fragment thereof, an anti-LIV 1 antibody or anti-PD-antigen-binding fragment thereof, or anti-PD-binding fragment thereof.

In some embodiments, the anti-TROP-2 antibody or antigen binding fragment thereof comprises:

(1) HCDR1 of the amino acid sequence shown in SEQ ID NO. 1, HCDR2 of the amino acid sequence shown in SEQ ID NO. 2, HCDR3 of the amino acid sequence shown in SEQ ID NO. 3, LCDR1 of the amino acid sequence shown in SEQ ID NO. 4, LCDR2 of the amino acid sequence shown in SEQ ID NO. 5, and LCDR3 of the amino acid sequence shown in SEQ ID NO. 6;

(2) A heavy chain variable region having an amino acid sequence at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 7, and a light chain variable region having an amino acid sequence at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 8, and comprising an HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3 set forth in (1) above;

(3) A heavy chain variable region comprising the amino acid sequence shown in SEQ ID NO. 7, and a light chain variable region comprising the amino acid sequence shown in SEQ ID NO. 8;

(4) A heavy chain having an amino acid sequence at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 9, and a light chain having an amino acid sequence at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 10, and comprising HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3 as set forth in (1) above; or (b)

(5) A heavy chain comprising the amino acid sequence shown in SEQ ID NO. 9, and a light chain comprising the amino acid sequence shown in SEQ ID NO. 10.

In some embodiments, the C-terminal lysine of the heavy chain constant region of an anti-TROP-2 antibody or antigen binding fragment thereof may be present or absent, the deletion of the C-terminal lysine of the heavy chain constant region typically occurring during recombinant expression. In some embodiments, the C-terminal lysine of the amino acid sequence shown in SEQ ID NO. 9 is deleted as shown in SEQ ID NO. 11.

In some embodiments, the heavy chain of the anti-TROP-2 antibody or antigen-binding fragment thereof has an amino acid sequence shown in SEQ ID NO. 9 and the light chain has an amino acid sequence shown in SEQ ID NO. 10. In some embodiments, the heavy chain of the anti-TROP-2 antibody or antigen-binding fragment thereof has an amino acid sequence shown in SEQ ID NO. 11 and the light chain has an amino acid sequence shown in SEQ ID NO. 10.

Sequence information for exemplary anti-TROP-2 antibodies of the disclosure, or antigen binding fragments thereof, is shown in table S1 below.

TABLE S1 sequence information of anti-TROP-2 antibodies or antigen binding fragments thereof

Method for producing antibodies having thiol groups or antigen-binding fragments thereof

The present disclosure also provides a method of producing an antibody or antigen-binding fragment thereof having a thiol group, comprising: reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof, wherein the reaction temperature is greater than 10 ℃.

In some embodiments, the reaction temperature is from 10.5 ℃ to 20 ℃. In some embodiments, the reaction temperature is from 10.5 ℃ to 15 ℃. In some embodiments, the reaction temperature is from 10.5 ℃ to 14 ℃. In some embodiments, the reaction temperature is 10.5 ℃ to 11 ℃, 11 ℃ to 14 ℃, or 11 ℃ to 13 ℃. In some embodiments, the reaction temperature is 10.5 ℃, 11 ℃, 11.5 ℃, 12 ℃, 12.5 ℃, 13 ℃, 13.5 ℃, 14 ℃, 14.5 ℃, 15 ℃, or a range formed of any of the above values.

In some embodiments, the reducing agent may be tris (2-carboxyethyl) phosphine or a salt thereof, dithiothreitol, or 2-mercaptoethanol. In some embodiments the reducing agent is tris (2-carboxyethyl) phosphine or a salt thereof, preferably tris (2-carboxyethyl) phosphine hydrochloride.

In some embodiments, the time of the reaction is from 1 to 10 hours. In some embodiments, the time of the reaction is from 1 to 5 hours. In some embodiments, the time of the reaction is 2 to 4 hours. In some embodiments, the time of the reaction is 2 to 3 hours. In some embodiments, the time of the reaction is 2.5 to 3 hours. In some embodiments, the time of the reaction is 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, 3 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours, 3.5 hours, 3.6 hours, 3.7 hours, 3.8 hours, 3.9 hours, 4 hours, or a range formed of any of the above.

In some embodiments, the pH of the reaction is from 5 to 9. In some embodiments, the pH of the reaction is from 6 to 8. In some embodiments, the pH of the reaction is from 6.5 to 7.5. In some embodiments, the pH of the reaction is from 6.9 to 7.2. In some embodiments, the pH of the reaction is 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, or a range formed by any of the above.

In some embodiments, the thiol-bearing antibody or antigen-binding fragment thereof is used to prepare an antibody drug conjugate having a DAR value of 3-5, or 3.5-4.5. In some embodiments, the DAR value is 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5.

In some embodiments, the antibodies or antigen binding fragments thereof having a thiol group are used to prepare antibody drug conjugates having a D4 content in the range of 50% or more, 55% or more, 60% or more, or 65% or more, or 50% to 90%, 50% to 80%, 50% to 70%, 50% to 60%, 60% to 70%, or 55% to 65%. In some embodiments, the amount of D4 in the antibody drug conjugate is 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, or 65%. In some embodiments, the amount of D8 in the antibody drug conjugate is 5% or less, 2% or less, or 1% or less, or 0%.

Cytotoxic drug

The cytotoxic drug used in the present disclosure is not particularly limited as long as it has an antitumor effect and has a substituent or structure capable of being linked to the linker of the present disclosure.

The cytotoxic drugs used in the present disclosure may be, for example, alkaloids, antimetabolites, antitumor antibiotics, alkylating agents, platinum agents, and the like. In some embodiments, the cytotoxic drug is a tubulin inhibitor class cytotoxic drug or a cytotoxic drug that acts on DNA. In some embodiments, the tubulin inhibitor class of cytotoxic drugs include, but are not limited to, maytansinoids, auristatins and dolastatins, tubulysins, cryptomycins, and Eribulin (Eribulin) or derivatives thereof. In some embodiments, the cytotoxic agents that act on DNA include, but are not limited to, calicheamicin (Calicheamicin) s, duocarmycin (Duocarmycin) s, an angleromycin derivative PBD (Pyrrolobenzodiazepine), topoisomerase I inhibitors, and topoisomerase II inhibitors.

In some embodiments, the cytotoxic agent is a tubulin inhibitor.

In some embodiments, the cytotoxic agent is eribulin or a derivative thereof.

Joint-payload

Cytotoxic agents used in the present disclosure may be linked to an antibody or antigen binding fragment thereof via a linker. The linkers used in the present disclosure preferably have an N-substituted maleimide group.

The linker-payload used in the present disclosure is not particularly limited as long as it is a compound capable of reacting with a thiol group generated by reducing an interchain disulfide bond of an antibody or an antigen-binding fragment thereof. The linker-payload used in the present disclosure is preferably a linker-payload having an N-substituted maleimide group, which can react with a thiol group generated by reducing an interchain disulfide bond of an antibody or antigen-binding fragment thereof, thereby being linked to the antibody or antigen-binding fragment thereof. The linker-payload used in the present disclosure is more preferably a compound of the structure shown in formula II:

II，

wherein R is ¹ Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl, R ² Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl; alternatively, R ¹ And R is ² Together with the atoms to which they are attached form an optionally substituted 5-to 8-membered heterocyclic group. In some embodiments, the R ¹ And R is ² Each independently selected from hydrogen atoms or C _1-5 Alkyl (preferably C _1-4 Alkyl radicals, e.g. C _1-3 Alkyl). In some embodiments, the R ¹ And R is R ² Each independently selected from hydrogen atom, methyl, ethyl, propyl or isopropyl. In some embodiments, the R ¹ And R is ² Is a hydrogen atom。

In some embodiments, the linker-payload is a compound of the structure shown in formula II-1:

II-1。

it is to be understood that the linker-payloads used in the present disclosure are not limited to the above-described compounds, and that all types of linker-payloads can be applied to the preparation methods of the present disclosure as long as they have a functional group for thiol reaction with the antibody or antigen-binding fragment thereof generated after reduction of interchain disulfide bonds.

Pharmaceutical composition

In one aspect, the present disclosure provides a pharmaceutical composition comprising an antibody drug conjugate produced by the preparation method of the present disclosure, or an isomer, a pharmaceutically acceptable salt, or a solvate of the antibody drug conjugate, an isomer, a pharmaceutically acceptable salt thereof. In some embodiments, the pharmaceutical compositions of the present disclosure further comprise a pharmaceutically acceptable excipient. Pharmaceutically acceptable excipients include, for example, excipients, diluents, encapsulating materials, fillers, buffers or other agents.

Use of the same

The present disclosure also provides for the use of antibody drug conjugates or the pharmaceutical compositions produced by the methods of preparation of the present disclosure.

In one aspect, the present disclosure provides the use of an antibody drug conjugate produced by a method of preparation of the present disclosure or the pharmaceutical composition in the manufacture of a medicament for the treatment of a disease expressing an antigen to which the antibody or antigen binding fragment thereof binds. In some embodiments, the present disclosure provides for the use of an antibody drug conjugate produced by a method of preparation of the present disclosure or the pharmaceutical composition in the manufacture of a medicament for treating a tumor. In some embodiments, the present disclosure provides the use of an antibody drug conjugate produced by the methods of preparation of the present disclosure or the pharmaceutical composition in the manufacture of a medicament for the treatment of an autoimmune disease.

In one aspect, the present disclosure provides a method of treating a disease expressing an antigen to which the antibody or antigen-binding fragment thereof binds, comprising administering to a subject in need thereof a therapeutically effective amount of an antibody drug conjugate produced by the methods of preparation of the present disclosure or the pharmaceutical composition. In some embodiments, the present disclosure provides a method of treating a tumor comprising administering to a subject in need thereof a therapeutically effective amount of an antibody drug conjugate produced by the methods of preparation of the present disclosure or the pharmaceutical composition. The present disclosure provides a method of treating an autoimmune disease comprising administering to a subject in need thereof a therapeutically effective amount of an antibody drug conjugate produced by the methods of preparation of the present disclosure or the pharmaceutical composition.

In some embodiments, the tumor is a TROP-2-expressing tumor.

In some embodiments, the tumor is biliary tract cancer, carcinoma sarcoma, esophageal cancer, gastroesophageal junction cancer, breast cancer, gastric cancer, pancreatic cancer, head and neck cancer, colorectal cancer, renal cancer, cervical cancer, ovarian cancer, endometrial cancer, uterine cancer, melanoma, pharyngeal cancer, oral cancer, skin cancer, lung cancer, urinary tract cancer, prostate cancer, bladder cancer, gastrointestinal stromal tumor, squamous cell carcinoma, peritoneal cancer, liver cancer, uterine cancer, salivary gland cancer, vulval cancer, thyroid cancer, penile cancer, leukemia, malignant lymphoma, plasmacytoma, or myeloma.

Interpretation and definition

The following terms used in this disclosure have the following meanings, unless otherwise indicated. A particular term, unless otherwise defined, shall not be construed as being ambiguous or otherwise unclear, but shall be construed in accordance with the ordinary meaning in the art. When trade names are presented herein, it is intended to refer to their corresponding commercial products or active ingredients thereof.

The term "substituted" means that any one or more hydrogen atoms on a particular atom is substituted with a substituent, provided that the valence of the particular atom is normal and the substituted compound is stable. When the substituent is oxo (i.e., =o), meaning that two hydrogen atoms are substituted, oxo does not occur on the aromatic group. "optionally substituted" means that the substituent may or may not be substituted, and the kind and number of substituents may be arbitrary on the basis that they can be chemically achieved unless otherwise specified.

When any variable (e.g., R) occurs more than once in the composition or structure of a compound, its definition in each case is independent. Thus, for example, if one group is substituted with 2R's, then each R has an independent option.

The term "mercapto" refers to a-SH group.

As used herein, "- (succinimid-3-yl-N) -" has the structure:

。

as used herein, the structure of the "N-substituted maleimide group" is as follows:

。

unless otherwise indicated, a wedge-shaped solid key is used) And a wedge-shaped dotted bond (+>) Representing the absolute configuration of a stereogenic center.

When a group has a bondable site, the bond of the site to other groups may be performed using wavy lines unless otherwise specified) And (3) representing.

As used herein, a compound formed by substitution of an atom or group of atoms in a parent compound molecule with other atoms or groups of atoms is referred to as a "derivative" of the parent compound.

The compounds of the present disclosure may exist in particular geometric or stereoisomeric forms. The present disclosure contemplates all such compounds, including cis and trans isomers, the levorotatory and dextrorotatory isomers, (R) -and (S) -enantiomers, diastereomers, (D) -isomers, (L) -isomers, and racemic mixtures and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the disclosure. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomers and mixtures thereof are included within the scope of the present disclosure.

Unless otherwise indicated, the term "cis-trans isomer" or "geometric isomer" is caused by the inability of a double bond or a single bond of a ring-forming carbon atom to rotate freely.

Unless otherwise indicated, the term "enantiomer" refers to stereoisomers that are mirror images of each other.

Unless otherwise indicated, the term "diastereoisomer" refers to stereoisomers of a molecule having two or more chiral centers and having a non-mirror relationship between the molecules.

The compounds and intermediates of the present disclosure may also exist in different tautomeric forms, and all such forms are included within the scope of the disclosure. The term "tautomer" or "tautomeric form" refers to structural isomers of different energies that can interconvert via a low energy barrier. For example, proton tautomers (also known as proton transfer tautomers) include tautomers via proton transfer, such as keto-enol and imine-enamine isomerisation. A specific example of a proton tautomer is an imidazole moiety, where a proton can migrate between two ring nitrogens. Valence tautomers include tautomers by recombination of some bond-forming electrons.

A "histidine buffer" is a buffer that contains histidine ions. Examples of histidine buffers include histidine-hydrochloric acid buffer, histidine-acetic acid buffer, histidine-phosphate buffer, and the like. Histidine-hcl buffers can be prepared using histidine (e.g., L-histidine) and further pH adjusted with hcl; or using histidine (e.g., L-histidine) and histidine hydrochloride or a hydrate thereof (e.g., histidine hydrochloride monohydrate). Histidine-acetate buffers can be prepared using histidine (e.g., L-histidine) and further pH adjusted with acetic acid. Histidine-phosphate buffers can be prepared using histidine (e.g., L-histidine) and further pH adjusted with phosphoric acid.

The term "treating" means administering a compound or pharmaceutical composition of the present disclosure to prevent, ameliorate or eliminate a disease or one or more symptoms associated with the disease, and includes, but is not limited to:

(i) Preventing the occurrence of a disease or disease state in a mammal, particularly when such mammal is susceptible to the disease state, but has not been diagnosed as having the disease state;

(ii) Inhibiting a disease or disease state, i.e., inhibiting its progression;

(iii) Remit a disease or condition, even if the disease or condition subsides;

(iv) Reducing any direct or indirect pathological consequences of the disease or disease state.

The term "therapeutically effective amount" means an amount of a compound of the present disclosure that (i) treats or prevents a particular disease, condition, or disorder, (ii) alleviates, ameliorates, or eliminates one or more symptoms of a particular disease, condition, or disorder, or (iii) prevents or delays the onset of one or more symptoms of a particular disease, condition, or disorder described herein. The amount of a compound or pharmaceutical composition of the present disclosure that constitutes a "therapeutically effective amount" can vary depending on, for example, the compound or pharmaceutical composition and its ability to elicit a desired response in an individual, the disease state and its severity, the mode of administration, and the age, sex, and weight of the mammal to be treated. A therapeutically effective amount can also be routinely determined by one of ordinary skill in the art based on its own knowledge and disclosure.

The term "pharmaceutically acceptable" is intended to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

The term "pharmaceutically acceptable salt" refers to salts of a compound (e.g., an antibody drug conjugate of the present disclosure) that are safe and effective when used in a mammal and that have the desired biological activity, and may be, for example, metal salts, ammonium salts, salts with organic bases, salts with inorganic acids, salts with organic acids, salts with basic or acidic amino acids, and the like.

The term "adjuvant" refers to any ingredient other than the active ingredient (e.g., an antibody drug conjugate of the present disclosure). The choice of excipients will depend to a large extent on factors such as the particular mode of administration, the efficacy of the excipient on solubility and stability, and the nature of the dosage form.

The term "solvate" refers to a substance formed by association of a compound with a solvent molecule.

The term "antibody" is used in its broadest sense and includes, but is not limited to, monoclonal antibodies, polyclonal antibodies, and multiple antibody structures of multispecific antibodies (e.g., bispecific antibodies, trispecific antibodies) so long as they exhibit the desired antigen-binding activity.

An "antigen-binding fragment" of an antibody refers to one or more fragments of an antibody that retain the function of specifically binding an antigen (e.g., a TROP-2 protein). It has been demonstrated that the antigen binding function of an antibody can be performed by fragments of full length antibodies. Examples of what are encompassed by the term "antigen binding fragment" of an antibody include: (i) Fab fragments: monovalent fragments consisting of VL, VH, CL and CH1 domains; (ii) A F (ab') 2 fragment, a bivalent fragment comprising two Fab fragments linked at the hinge region by a disulfide bridge; (iii) an Fd fragment consisting of VH and CH1 domains; (iv) Fv fragments consisting of the VL and VH domains of the antibody single arm; (v) dAb fragments consisting of VH domains (see Wardet alNature 341:544-546 (1989)); and (vi) nanobodies, an antibody comprising a single variable domain and two constant domains. In addition, although Fv fragmentsThe two domains of the segment, VL and VH, are encoded by different genes, but VH and VL can be joined by linkers to form a single protein chain by recombinant means, wherein the VL and VH pair to form monovalent molecules called single chain Fv (scFv) (see Bird et alScience.242:423-426 (1988); huston et al, proc.Natl.Acad.Sci.85:5879-5883 (1988)), are also encompassed by the term antigen-binding fragment. These antibody fragments can be obtained by conventional techniques known to those skilled in the art, and the fragments can be functionally screened by the same method as the full-length antibody.

The antibodies of the present disclosure or antigen binding fragments thereof may be of the IgG1, igG2, igG3 or IgG4 isotype. The term "isotype" refers to the type of antibody encoded by the heavy chain constant region gene. In some embodiments, the antibodies of the disclosure, or antigen binding fragments thereof, are of the IgG1 isotype. The antibodies of the present disclosure or antigen binding fragments thereof may be derived from any species, including but not limited to mice, rats, rabbits, non-human primates (e.g., chimpanzees, cynomolgus monkeys, spider monkeys, macaques), llamas, and humans. The antibodies or antigen binding fragments thereof of the present disclosure may be murine, chimeric, humanized or human antibodies.

The term "mouse antibody" or "murine antibody" refers to an antibody in which both the framework and CDR regions in the variable region are derived from the germline immunoglobulin sequences of a mouse. Furthermore, if the antibody comprises constant regions, the constant regions are also derived from the mouse germline immunoglobulin sequences. The murine antibodies of the present disclosure may include amino acid residues not encoded by the mouse germline immunoglobulin sequences (e.g., mutations introduced by random or point mutations in vitro or by somatic mutations in vivo), but "mouse antibodies" or "murine antibodies" do not include antibodies in which CDR sequences derived from other mammalian germline species are inserted into the mouse framework sequences.

The "chimeric antibody" is an antibody in which a variable region of a murine antibody is fused to a constant region of a human antibody, and can reduce an immune response induced by the murine antibody. The chimeric antibody is established by first establishing hybridoma secreting mouse-derived specific monoclonal antibody, cloning variable region gene from hybridoma cell, cloning constant region gene of human antibody as required, connecting mouse variable region gene and human constant region gene into chimeric gene, inserting into expression vector, and finally expressing chimeric antibody in eukaryotic system or prokaryotic system.

"humanized antibodies" are the following antibodies: the antibodies contain Complementarity Determining Regions (CDRs) derived from a non-human antibody and framework regions and constant regions derived from a human antibody.

The term "CDR" (complementarity determining region), also known as "hypervariable region". Natural four-chain antibodies typically comprise six CDRs, three in the heavy chain variable region and three in the light chain variable region.

The term "variable region" refers to a domain of about 100 to 110 or more amino acids defined by the N-terminal domain of the light or heavy chain of an antibody that is primarily responsible for antigen recognition. The terms light chain variable region (VL) and heavy chain variable region (VH) refer to these light chain and heavy chain domains, respectively.

The term "identity", also known as consistency. "percent (%) identity" of amino acid sequences refers to the percentage of amino acid residues in an aligned sequence that are identical to the amino acid residues of a particular amino acid sequence shown herein, after aligning the aligned sequence to the particular amino acid sequence shown herein and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and without regard to any conservative substitutions as part of the sequence identity. Amino acid sequence alignment for identity can be performed in a variety of ways within the skill in the art, such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. One skilled in the art can determine the appropriate parameters for aligning sequences, including any algorithm needed to obtain the maximum alignment over the entire length of the compared sequences.

The term "subject" includes any human or non-human animal. The term "non-human animal" includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dogs, cats, horses, cows, chickens, amphibians, reptiles, and the like. Preferably, the subject according to the present disclosure is a human. Unless indicated, the terms "patient" or "subject" are used interchangeably. "subjects in need thereof" include those already with the disease or condition, those at risk of developing the disease or condition, as well as those who are likely to have the disease or condition and whose purpose is to prevent, delay or attenuate the disease or condition.

As used herein, "about" means within an acceptable error range for a particular value as determined by one of ordinary skill in the art, depending in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, "about" may mean within 1 or more than 1 standard deviation per the practice of the art. Alternatively, "about" may mean a range of up to + -5%, e.g., fluctuating within + -2%, within + -1%, or within + -0.5% of a given specific numerical range. When a particular value is given within the scope of this disclosure, unless otherwise indicated, the meaning of "about" should be considered to be within an acceptable error range for that particular value. In this context, unless otherwise indicated, the values of step parameters or conditions are by default modified by "about".

The terms "comprises," "comprising," and "includes" (comprise, comprises or comprising) and equivalents thereof (e.g., contain, contains, containing, include, includes and including) are to be construed as "including but not limited to," meaning that other unspecified elements, components, and steps are contemplated in addition to those listed.

In this document, singular terms encompass plural referents and vice versa, unless the context clearly dictates otherwise.

Detailed Description

The present disclosure also provides some specific embodiments below, but the scope of protection of the present disclosure is not limited thereto:

embodiment 1. A method of preparing an antibody drug conjugate comprising: (i) Reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof; (ii) Reacting the linker-payload with the thiol-bearing antibody or antigen-binding fragment thereof obtained in step (i); wherein the reaction temperature in step (i) is greater than 10 ℃.

Embodiment 2. The method of preparation according to embodiment 1, wherein the resulting antibody drug conjugate has a DAR value of 3-5.

Embodiment 3. The method of preparation of embodiment 2 wherein the antibody drug conjugate produced has a DAR value of 3.5-4.5.

Embodiment 4. The method of preparation of embodiment 3, wherein the resulting antibody drug conjugate has a DAR value of 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5.

Embodiment 5. The method of any of embodiments 1-4, wherein the amount of D4 of the antibody drug conjugate produced is 50% or more, 55% or more, 60% or more, or 65% or more.

Embodiment 6. The method of any of embodiments 1-4, wherein the amount of D4 of the antibody drug conjugate produced is in the range of 50% to 90%.

Embodiment 7. The method of preparation of embodiment 6, wherein the amount of D4 of the antibody drug conjugate produced is in the range of 50% to 80%.

Embodiment 8. The method of preparation of embodiment 7 wherein the amount of D4 of the antibody drug conjugate produced is in the range of 50% to 70%.

Embodiment 9. The method of preparation of embodiment 8 wherein the amount of D4 of the antibody drug conjugate produced is in the range of 50% to 60%, 60% to 70%, or 55% to 65%.

Embodiment 10. The method of any of embodiments 1-9, wherein the reaction temperature in step (i) is from 10.5 ℃ to 20 ℃.

Embodiment 11. The method of embodiment 10, wherein the reaction temperature in step (i) is from 10.5 ℃ to 15 ℃.

Embodiment 12. The method of embodiment 11, wherein the reaction temperature in step (i) is from 10.5 ℃ to 14 ℃.

Embodiment 13. The method of embodiment 12, wherein the reaction temperature in step (i) is from 10.5 ℃ to 11 ℃.

Embodiment 14. The method of any of embodiments 1-13, wherein the ratio of the reducing agent to the amount of the substance of the antibody or antigen binding fragment thereof is 1:1 to 4:1, 2:1 to 3:1, or 2.4:1 to 2.5:1.

Embodiment 15. The method of any of embodiments 1-14, wherein the reducing agent is tris (2-carboxyethyl) phosphine or a salt thereof, dithiothreitol, or 2-mercaptoethanol, preferably tris (2-carboxyethyl) phosphine or a salt thereof.

Embodiment 16. The method of preparation of embodiment 15 wherein the reducing agent is tris (2-carboxyethyl) phosphine hydrochloride.

Embodiment 17. The method of any of embodiments 1-16, wherein the buffer is HEPES buffer, histidine buffer, phosphate buffer, borate buffer or acetate buffer, preferably histidine buffer.

Embodiment 18. The method of any of embodiments 1-17, wherein the time of the reaction in step (i) is from 1 to 10 hours, from 1 to 5 hours, from 2 to 4 hours, from 2 to 3 hours, or from 2.5 to 3 hours.

Embodiment 19. The method of any of embodiments 1-18, wherein the reaction temperature in step (ii) is from 10 ℃ to 20 ℃, from 10.5 ℃ to 15 ℃, from 10.5 ℃ to 14 ℃, or from 10.5 ℃ to 11 ℃.

Embodiment 20. The method of preparation of any of embodiments 1-19, wherein the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is 2:1 to 10:1, 3:1 to 7:1, 4:1 to 6:1, 4.5:1 to 5.5:1, or 4.7:1 to 4.8:1.

Embodiment 21. The method of any of embodiments 1-20, wherein the time of the reaction in step (ii) is from 1 to 5 hours, from 2 to 4 hours, or from 2 to 3 hours.

Embodiment 22. The method of any of embodiments 1-21, wherein the antibody or antigen-binding fragment thereof is an anti-TROP-2 antibody or antigen-binding fragment thereof, an anti-HER 3 antibody or antigen-binding fragment thereof, an anti-ROR 1 antibody or antigen-binding fragment thereof, an anti-B7-H3 antibody or antigen-binding fragment thereof, an anti-CD 79B antibody or antigen-binding fragment thereof, an anti-CLDN 18.2 antibody or antigen-binding fragment thereof, an anti-c-MET antibody or antigen-binding fragment thereof, or an anti-LIV-1 antibody or antigen-binding fragment thereof.

Embodiment 23. The method of making according to embodiment 22, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises HCDR1 of the amino acid sequence shown in SEQ ID NO. 1, HCDR2 of the amino acid sequence shown in SEQ ID NO. 2, HCDR3 of the amino acid sequence shown in SEQ ID NO. 3, LCDR1 of the amino acid sequence shown in SEQ ID NO. 4, LCDR2 of the amino acid sequence shown in SEQ ID NO. 5, and LCDR3 of the amino acid sequence shown in SEQ ID NO. 6.

Embodiment 24. The method of making according to embodiment 23, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises a heavy chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 7, and a light chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 8.

Embodiment 25. The method of making according to embodiment 23 or 24, wherein the anti-TROP-2 antibody or antigen binding fragment thereof comprises a heavy chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 9 or 11, and a light chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 10.

Embodiment 26. The method of any of embodiments 1-25, wherein the linker-payload has an N-substituted maleimide group.

Embodiment 27.The method of preparation of embodiment 26, wherein the linker-payload has the structure of formula II:II, wherein R is ¹ Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl, R ² Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl; alternatively, R ¹ And R is ² Together with the atoms to which they are attached form an optionally substituted 5-to 8-membered heterocyclic group.

Embodiment 28. The method of preparation according to embodiment 27, wherein the R ¹ And R is R ² Each independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl; preferably, R ¹ And R is ² Is a hydrogen atom.

Embodiment 29. The antibody drug conjugate produced by the method of any of embodiments 1-28, wherein the antibody drug conjugate has a DAR value of 3-5, or 3.5-4.5, and a D4 content of 50% or more, 55% or more, 60% or more, or 65% or more.

Embodiment 30. The antibody drug conjugate of embodiment 29 wherein the antibody drug conjugate has a D4 content in the range of 50% to 90%.

Embodiment 31. The antibody drug conjugate of embodiment 30 wherein the antibody drug conjugate has a D4 content in the range of 50% to 80%.

Embodiment 32. The antibody drug conjugate of embodiment 31 wherein the antibody drug conjugate has a D4 content in the range of 50% to 70%.

Embodiment 33. The antibody drug conjugate of embodiment 32 wherein the antibody drug conjugate has a D4 content in the range of 50% to 60%, 60% to 70%, or 55% to 65%.

Embodiment 34 the antibody drug conjugate of any of embodiments 29-33, wherein the antibody or antigen-binding fragment thereof is an anti-TROP-2 antibody or antigen-binding fragment thereof, an anti-HER 3 antibody or antigen-binding fragment thereof, an anti-ROR 1 antibody or antigen-binding fragment thereof, an anti-B7-H3 antibody or antigen-binding fragment thereof, an anti-CD 79B antibody or antigen-binding fragment thereof, an anti-CLDN 18.2 antibody or antigen-binding fragment thereof, an anti-c-MET antibody or antigen-binding fragment thereof, or an anti-LIV-1 antibody or antigen-binding fragment thereof.

Embodiment 35. The antibody drug conjugate of embodiment 34 wherein the anti-TROP-2 antibody or antigen binding fragment thereof comprises HCDR1 of the amino acid sequence shown in SEQ ID No. 1, HCDR2 of the amino acid sequence shown in SEQ ID No. 2, HCDR3 of the amino acid sequence shown in SEQ ID No. 3, LCDR1 of the amino acid sequence shown in SEQ ID No. 4, LCDR2 of the amino acid sequence shown in SEQ ID No. 5, and LCDR3 of the amino acid sequence shown in SEQ ID No. 6.

Embodiment 36. The antibody drug conjugate of embodiment 35, wherein the anti-TROP-2 antibody or antigen binding fragment thereof comprises a heavy chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID No. 7, and a light chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID No. 8.

Embodiment 37. The antibody drug conjugate of embodiment 35 or 36, wherein the anti-TROP-2 antibody or antigen binding fragment thereof comprises a heavy chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence shown in SEQ ID No. 9 or 11, and a light chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence shown in SEQ ID No. 10.

Embodiment 38 the antibody drug conjugate of any of embodiments 29-37, wherein the structure of the antibody drug conjugate is shown in formula I below:i, wherein Ab is an antibody or antigen binding fragment thereof, n is selected from 3-5, preferably 3.5-4.5, R ¹ Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl, R ² Selected from hydrogen atoms, optionally substituted C _1-6 Alkyl, optionally substituted C _3-7 Cycloalkyl, optionally substituted 3-to 7-membered heterocyclyl, optionally substituted C _6-10 Aryl, optionally substituted 5-to 12-membered heteroaryl; alternatively, R ¹ And R is ² Together with the atoms to which they are attached form an optionally substituted 5-to 8-membered heterocyclic group; and, the 3-position of- (succinimid-3-yl-N) -in formula I is linked to Ab.

Embodiment 39 the antibody drug conjugate of embodiment 38 wherein the R ¹ And R is R ² Each independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl; preferably, R ¹ And R is ² Is a hydrogen atom.

Embodiment 40. A pharmaceutical composition comprising the antibody drug conjugate of any of embodiments 29-39, or an isomer, pharmaceutically acceptable salt, or solvate of the antibody drug conjugate, isomer, pharmaceutically acceptable salt thereof; optionally, the pharmaceutical composition further comprises pharmaceutically acceptable excipients.

Embodiment 41 use of the antibody drug conjugate of any of embodiments 29-39 or the pharmaceutical composition of embodiment 40 in the manufacture of a medicament for the treatment of a tumor.

Embodiment 42. The use of embodiment 41, wherein the tumor is biliary tract cancer, carcinoma sarcoma, esophageal cancer, gastroesophageal junction cancer, breast cancer, gastric cancer, pancreatic cancer, head and neck cancer, colorectal cancer, renal cancer, cervical cancer, ovarian cancer, endometrial cancer, uterine cancer, melanoma, pharyngeal cancer, oral cancer, skin cancer, lung cancer, urinary tract cancer, prostate cancer, bladder cancer, gastrointestinal stromal tumor, squamous cell cancer, peritoneal cancer, liver cancer, uterine cancer, salivary gland cancer, vulval cancer, thyroid cancer, penile cancer, leukemia, malignant lymphoma, plasmacytoma, or myeloma.

Embodiment 43. A method of treating a tumor comprising administering to a subject in need thereof a therapeutically effective amount of the antibody drug conjugate of any of embodiments 29-39 or the pharmaceutical composition of embodiment 40.

Embodiment 44. The method of embodiment 43, wherein the tumor is biliary tract cancer, carcinoma sarcoma, esophageal cancer, gastroesophageal junction cancer, breast cancer, gastric cancer, pancreatic cancer, head and neck cancer, colorectal cancer, renal cancer, cervical cancer, ovarian cancer, endometrial cancer, uterine cancer, melanoma, pharyngeal cancer, oral cancer, skin cancer, lung cancer, urinary tract cancer, prostate cancer, bladder cancer, gastrointestinal stromal tumor, squamous cell cancer, peritoneal cancer, liver cancer, uterine cancer, salivary gland cancer, vulval cancer, thyroid cancer, penile cancer, leukemia, malignant lymphoma, plasmacytoma, or myeloma.

Embodiment 45. A method of producing an antibody or antigen-binding fragment thereof having a thiol group, comprising: reacting the antibody or antigen-binding fragment thereof with a reducing agent in a buffer to reduce interchain disulfide bonds of the antibody or antigen-binding fragment thereof, wherein the reaction temperature is greater than 10 ℃; the resulting thiol-bearing antibodies, or antigen-binding fragments thereof, are used to prepare antibody drug conjugates having a DAR value of 3-5, or 3.5-4.5, and a D4 content of 50% or more, 55% or more, 60% or more, or 65% or more.

Embodiment 46. The method of embodiment 45, wherein the amount of D4 of the antibody drug conjugate is in the range of 50% to 90%.

Embodiment 47. The method of embodiment 46, wherein the antibody drug conjugate has a D4 content in the range of 50% to 80%.

Embodiment 48. The method of embodiment 47, wherein the antibody drug conjugate has a D4 content in the range of 50% to 70%.

Embodiment 49. The method of embodiment 48, wherein the amount of D4 of the antibody drug conjugate is in the range of 50% to 60%, 60% to 70%, or 55% to 65%.

Embodiment 50. The method of any of embodiments 45-49, wherein the reaction temperature is from 10.5 ℃ to 20 ℃.

Embodiment 51. The method of embodiment 50, wherein the reaction temperature is from 10.5 ℃ to 15 ℃.

Embodiment 52. The method of embodiment 51, wherein the reaction temperature is from 10.5 ℃ to 14 ℃.

Embodiment 53. The method of embodiment 52, wherein the reaction temperature is from 10.5 ℃ to 11 ℃.

Embodiment 54. The method of any of embodiments 45-53, wherein the ratio of the reducing agent to the amount of the substance of the antibody or antigen binding fragment thereof is 1:1 to 4:1, 2:1 to 3:1, or 2.4:1 to 2.5:1.

Embodiment 55 the method of any of embodiments 45-54, wherein the reducing agent is tris (2-carboxyethyl) phosphine or a salt thereof, dithiothreitol, or 2-mercaptoethanol, preferably tris (2-carboxyethyl) phosphine or a salt thereof.

Embodiment 56. The method of embodiment 55, wherein the reducing agent is tris (2-carboxyethyl) phosphine hydrochloride.

Embodiment 57 the method of any of embodiments 45-56, wherein the buffer is HEPES buffer, histidine buffer, phosphate buffer, borate buffer or acetate buffer, preferably histidine buffer.

Embodiment 58 the method of any of embodiments 45-57, wherein the time of the reacting is 1 to 10 hours, 1 to 5 hours, 2 to 4 hours, 2 to 3 hours, or 2.5 to 3 hours.

Embodiment 59 the method of any one of embodiments 45-58, wherein the antibody or antigen-binding fragment thereof is an anti-TROP-2 antibody or antigen-binding fragment thereof, an anti-HER 3 antibody or antigen-binding fragment thereof, an anti-ROR 1 antibody or antigen-binding fragment thereof, an anti-B7-H3 antibody or antigen-binding fragment thereof, an anti-CD 79B antibody or antigen-binding fragment thereof, an anti-CLDN 18.2 antibody or antigen-binding fragment thereof, an anti-c-MET antibody or antigen-binding fragment thereof, or an anti-LIV-1 antibody or antigen-binding fragment thereof.

Embodiment 60. The method of embodiment 59, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises HCDR1 of the amino acid sequence shown in SEQ ID NO. 1, HCDR2 of the amino acid sequence shown in SEQ ID NO. 2, HCDR3 of the amino acid sequence shown in SEQ ID NO. 3, LCDR1 of the amino acid sequence shown in SEQ ID NO. 4, LCDR2 of the amino acid sequence shown in SEQ ID NO. 5, and LCDR3 of the amino acid sequence shown in SEQ ID NO. 6.

Embodiment 61. The method of embodiment 60, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises a heavy chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 7, and a light chain variable region having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 8.

Embodiment 62. The method according to embodiment 60 or 61, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises a heavy chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 9 or 11, and a light chain having an amino acid sequence that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence set forth in SEQ ID NO. 10.

For clarity, the disclosure is further illustrated with examples, but the examples do not limit the scope of the disclosure. Those skilled in the art will readily recognize a variety of non-critical parameters that may be changed or modified to produce substantially similar results.

The anti-TROP-2 antibody hz-Ab35-1.3 used in the examples and the preparation method thereof are derived from the patent application document WO2023104080, the heavy chain amino acid sequence of which is shown as SEQ ID NO. 70 in WO2023104080, and the light chain amino acid sequence of which is shown as SEQ ID NO. 71 in WO 2023104080.

The linker-payload MC-GGFG-eribulin used in the examples and methods for its preparation are derived from patent application WO2023041006, the structure of which is shown in formula II-1 of the present disclosure.

Example 1: preparation of antibody drug conjugates

Reagent:

the antibody was hz-Ab35-1.3 and Linker-payload (Linker-payload) was MC-GGFG-eribulin.

The experimental procedure is as follows:

(1) The antibody hz-Ab35-1.3 was adjusted to a concentration of about 10 g/L, 0.3M Na with 20 mM histidine-HCl buffer (containing L-histidine 1.43 mg/mL, L-histidine hydrochloride monohydrate 2.27 mg/mL, pH 6.0) ₂ HPO ₄ The pH of the aqueous solution was adjusted to 7.0, and sucrose was added thereto so that the concentration of sucrose was 5% (w/v). The temperature of the solution is regulated to 10.5-14.0 ℃, 10 TCEP & HCl (tri (2-carboxyethyl) phosphine hydrochloride) aqueous solution of mM is added, the mass ratio of TCEP & HCl to antibody is 2.5:1, and the reaction is carried out for 2.5 hours in a dark condition under the conditions of stirring at 10.5-14.0 ℃ for 20-100 r/min.

(2) DMSO is added to make the final concentration of the antibody be 2% (v/v), and then 10% (g/L) of Linker-payload (MC-GGFG-Eribulin) dissolved in DMSO is added to make the ratio of the amount of the Linker-payload to the amount of the antibody be 4.8:1, and the reaction is carried out for 2 hours in a dark place under the condition of stirring at the temperature of 10.5-14.0 ℃ and at the speed of 20-100 revolutions per minute.

(3) Adding 10 mM N-acetylcysteine to make the ratio of the N-acetylcysteine to the antibody substance be 4:1, and reacting for 25-40 minutes. And then the reacted solution is replaced by a 30 kDa ultrafiltration membrane into 20 mM histidine-hydrochloric acid buffer solution (pH 6.0) to obtain the antibody drug conjugate.

According to the specific conditions of tables 1 and 2, antibody drug conjugates ADC1-ADC6 were synthesized, having the following structures:

，

the distribution of the number of cytotoxic drugs and the average number of links (n) per molecule of the antibodies of ADC1-ADC6 were measured by the method of example 2, and the specific results are shown in Table 3.

TABLE 1 specific parameters of step (1)

TABLE 2 specific parameters of step (2)

TABLE 3 DAR values for ADCs (i.e., n) containing the percentage of peak area of D0-D8

Note that: the peak area percentages of D1, D7 and D8 are all 0%.

Example 2: DAR value determination of antibody drug conjugates

The DAR value of the antibody drug conjugate is measured by adopting a Hydrophobic Interaction Chromatography (HIC) method, the hydrophobic property of protein molecules is improved by utilizing a neutral high-salt mobile phase, so that the protein molecules are combined with hydrophobic bonding in a chromatographic column, and then substances are eluted by gradually reducing the salt concentration and gradually increasing the proportion of isopropanol, wherein the substances are eluted firstly with low hydrophobicity and eluted later with high hydrophobicity.

The components of the antibody drug conjugate were separated using a non-porous PS/DVB filler bonded to butyl. The column specification was Sepax, proteomix HIC Butyl-NP5 (5 [ mu ] m,4.6 mm X100 mm), column temperature 25 ℃. The mobile phase A is 1.5M ammonium sulfate-50 mM phosphate buffer solution (pH 7.0) i-propanol=95:5 (v/v) (weighing ammonium sulfate 188.30 g and sodium dihydrogen phosphate dihydrate 7.41 g, adding 750 mL ultrapure water, stirring to dissolve completely, adjusting pH to 7.0 with 50% sodium hydroxide solution, adding ultrapure water to 950 mL, adding isopropanol 50 mL, mixing well, and filtering with 0.22 μm filter membrane. The mobile phase B is 50 mM phosphate buffer (pH 7.0) and isopropanol=80:20 (v/v) (weighing sodium dihydrogen phosphate dihydrate 6.24 g, adding 750 mL ultrapure water, stirring to dissolve completely, adjusting pH to 7.0 with 50% sodium hydroxide solution, adding ultrapure water to 800 mL, adding isopropanol 200 mL, mixing well, and filtering with 0.22 μm filter membrane. The ADC samples were diluted with ultrapure water to about 2.0 mg protein per 1. 1 mL as a test solution, 20 μg protein was injected and detected at 214 nm wavelength. The flow rate was 1.0. 1.0 mL/min and the gradient elution parameters were as shown in Table 4 below.

TABLE 4 gradient elution parameters

And (3) data processing, and quantitatively analyzing the results by adopting an area normalization method. The peak area percentages of D0, D1, D2, D3, D4, D5, D6, D7, and D8 were calculated, respectively, and the DAR value results were calculated. The calculation formula is as follows: DAR values= (D0 peak area percentage×0+d1 peak area percentage×1+d2 peak area percentage×2+d3 peak area percentage×3+d4 peak area percentage×4+d5 peak area percentage×5+d6 peak area percentage×6+d7 peak area percentage×7+d8 peak area percentage×8)/100%.

All patents, patent applications, and other identified publications are expressly incorporated herein by reference for the purpose of description and disclosure. These publications are provided solely for their disclosure prior to the filing date of the present disclosure. All statements as to the date or representation as to the contents of these documents are based on the information available to the applicant and do not constitute any admission as to the correctness of the dates or contents of these documents. Moreover, any reference to such publications herein in any country is not an admission that such publications are part of the common general knowledge in the art.

While the disclosure has been described in detail with respect to the general description and the specific embodiments thereof, it will be apparent to those skilled in the art that certain modifications and improvements can be made thereto based upon the disclosure. Accordingly, such modifications or improvements may be made without departing from the spirit of the disclosure, and are intended to be within the scope of the disclosure as claimed.

Claims

1. A method of preparing an antibody drug conjugate comprising:

；

Wherein,

and the DAR value of the prepared antibody drug conjugate is 3.5-4.5.

2. The method of preparation of claim 1, wherein the antibody drug conjugate produced has a DAR value of 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5.

3. The method of claim 1, wherein the antibody drug conjugate produced has a D4 content in the range of 55% to 65%.

4. The preparation process according to claim 1, wherein the reaction temperature in step (i) is 10.5 ℃ to 11 ℃.

5. The method of any one of claims 1-4, wherein the ratio of the amount of the reducing agent to the substance of the antibody or antigen-binding fragment thereof is from 2:1 to 3:1.

6. The method according to any one of claims 1 to 4, wherein the buffer is histidine buffer.

7. The production process according to any one of claims 1 to 4, wherein the reaction temperature in step (ii) is 10.5 ℃ to 14 ℃ and the time of the reaction in step (ii) is 2 to 3 hours.

8. The method of any one of claims 1-4, wherein the ratio of the amount of linker-payload to the amount of substance of the antibody or antigen binding fragment thereof in step (ii) is 4:1 to 6:1.

9. The method according to any one of claims 1 to 4, wherein the antibody or antigen-binding fragment thereof is an anti-TROP-2 antibody or antigen-binding fragment thereof.

10. The method according to claim 9, wherein the anti-TROP-2 antibody or antigen-binding fragment thereof comprises HCDR1 of the amino acid sequence shown in SEQ ID No. 1, HCDR2 of the amino acid sequence shown in SEQ ID No. 2, HCDR3 of the amino acid sequence shown in SEQ ID No. 3, LCDR1 of the amino acid sequence shown in SEQ ID No. 4, LCDR2 of the amino acid sequence shown in SEQ ID No. 5, and LCDR3 of the amino acid sequence shown in SEQ ID No. 6.

11. The method of claim 10, wherein the anti-TROP-2 antibody or antigen binding fragment thereof comprises a heavy chain variable region having an amino acid sequence at least 85% identical to the amino acid sequence set forth in SEQ ID No. 7 and a light chain variable region having an amino acid sequence at least 85% identical to the amino acid sequence set forth in SEQ ID No. 8.

12. The method of claim 10 or 11, wherein the anti-TROP-2 antibody comprises a heavy chain having an amino acid sequence at least 85% identical to the amino acid sequence set forth in SEQ ID No. 9, and a light chain having an amino acid sequence at least 85% identical to the amino acid sequence set forth in SEQ ID No. 10.