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EP-4201429-B1 - ANTIBODY-DRUG CONJUGATE INTERMEDIATE COMPRISING SN38 AND PREPARATION METHOD THEREFOR

EP4201429B1EP 4201429 B1EP4201429 B1EP 4201429B1EP-4201429-B1

Inventors

  • HUANG, CHANGJIANG
  • XIONG, JIUKAI
  • YAN, XinXin
  • YU, HONGXIA

Dates

Publication Date
20260506
Application Date
20221101

Claims (15)

  1. An antibody-drug conjugate intermediate represented by formula (I): wherein: X 1 is an alkane chain or a PEG chain, X 2 is H or -C(O)NR 1 R 2 , and R 1 is selected from the group consisting of hydrogen, halogen, hydroxyl, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 1-6 hydroxyalkyl, substituted or unsubstituted C 1-6 aminoalkyl, substituted or unsubstituted C 1-6 alkoxyl, substituted or unsubstituted C 1-6 alkylacyl, and substituted or unsubstituted C 1-6 alkylaldehyde; R 2 is selected from the group consisting of hydrogen and substituted or unsubstituted C 1-6 alkyl; wherein each substituted C 1-6 alkyl is optionally substituted with 1-5 substituents independently selected from the group consisting of halogen, hydroxyl, amino, carbonyl, carboxyl, 5-10-membered heterocyclyl and C 1-6 haloalkyl, wherein the 5-10-membered heterocyclyl has 1-3 heteroatoms selected from the group consisting of oxygen, nitrogen and sulfur.
  2. The antibody-drug conjugate intermediate according to claim 1, wherein X 1 is selected from the group consisting of -(CH 2 ) m - and -(CH 2 CH 2 O) p -, wherein: m is selected from 1, 2, 3, 4, 5, and 6, preferably, m is 5; p is selected from 1, 2, 3, 4, 5, and 6, preferably, p is 2; preferably, X 1 is selected from the group consisting of:
  3. The antibody-drug conjugate intermediate according to claim 1, wherein R 1 or R 2 is independently selected from the group consisting of: H, methyl, ethyl, propyl, butyl, pentyl, heptyl, methoxyl, ethoxyl, Cl, Br,
  4. The antibody-drug conjugate intermediate according to any one of claims 1-3, wherein X 2 is selected from the group consisting of:
  5. The antibody-drug conjugate intermediate according to claim 1, wherein the antibody-drug conjugate intermediate has a structure represented by formula (1)-(16):
  6. A method for producing an antibody-drug conjugate intermediate, wherein the antibody-drug conjugate intermediate is: or or or wherein, R 1 is selected from the group consisting of hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 1-6 hydroxyalkyl, substituted or unsubstituted C 1-6 aminoalkyl, substituted or unsubstituted C 1-6 alkoxyl, substituted or unsubstituted C 1-6 alkylacyl, and substituted or unsubstituted C 1-6 alkylaldehyde; R 2 is selected from the group consisting of hydrogen and substituted or unsubstituted C 1-6 alkyl; wherein each substituted C 1-6 alkyl is optionally substituted with 1-5 substituents independently selected from the group consisting of halogen, hydroxyl, amino, carbonyl, carboxyl, 5-10-membered heterocyclyl and C 1-6 haloalkyl, wherein the 5-10-membered heterocyclyl has 1-3 heteroatoms selected from the group consisting of oxygen, nitrogen and sulfur; preferably, R 1 or R 2 is selected from the group consisting of: H, methyl, ethyl, propyl, butyl, pentyl, heptyl, methoxyl, ethoxyl, Cl, Br, the method is selected from the following reaction process: or or or
  7. The method according to claim 6, wherein the compound (I-1) is selected from the group consisting of: or, the compound (I-2) is selected from the group consisting of: and
  8. The method according to claim 6, wherein the reaction process 1 comprises the following conditions: reaction A: dissolving compound a and compound b in a solvent, stirring at room temperature for an appropriate time, adding a reducing agent at low temperature, stirring for an appropriate time, and then stirring at room temperature overnight to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing extraction, drying and purification; reaction B: dissolving SN38 and DNPC in a solvent, adding an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing trituration and filtration; reaction C: dissolving a product obtained by reaction B in a solvent, adding a product obtained by reaction A and an organic base, stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction D: dissolving a product obtained by reaction C in a solvent, adding an acid, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, dissolving with Mc-VC-PAB-PNP in a solvent, stirring at low temperature for an appropriate time, and adding an organic base to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification.
  9. The method according to claim 6, wherein the reaction process 2 comprises the following conditions: reaction A: dissolving compound a and compound b in a solvent, stirring at room temperature for an appropriate time, adding a reducing agent at low temperature, stirring for an appropriate time, and then stirring at room temperature overnight to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing extraction, drying and purification; reaction B: dissolving SN38 and DNPC in a solvent, adding an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing trituration and filtration; reaction C: dissolving a product obtained by reaction B in a solvent, adding a product obtained by reaction A and an organic base, stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction D: dissolving a product obtained by reaction C in a solvent, adding an acid, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, dissolving with MP2-VC-PAB-PNP in a solvent, stirring at low temperature for an appropriate time, and adding an organic base to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification.
  10. The method according to claim 6, wherein the reaction process 3 comprises the following operating conditions: reaction A: dissolving compound a and compound b in a solvent, stirring at room temperature for an appropriate time, adding a reducing agent at low temperature, stirring for an appropriate time, and then stirring at room temperature overnight to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing extraction, drying and purification; reaction B: dissolving SN38 and DNPC in a solvent, adding an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing trituration and filtration; reaction C: dissolving a product obtained by reaction B in a solvent, adding a product obtained by reaction A and an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction D: dissolving a product obtained by reaction C in a solvent, adding bis(p-nitrophenyl) carbonate and an organic base, and stirring at constant temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction E: dissolving a product obtained by reaction D and an amine in a solvent, adding an organic base, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction F: dissolving a product obtained by reaction E in a solvent, adding an acid, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, dissolving with Mc-VC-PAB-PNP in a solvent, stirring at low temperature for an appropriate time, and adding an organic base to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification.
  11. The method according to claim 6, wherein the reaction process 4 comprises the following operating conditions: reaction A: dissolving compound a and compound b in a solvent, stirring at room temperature for an appropriate time, adding a reducing agent at low temperature, stirring for an appropriate time, and then stirring at room temperature overnight to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing extraction, drying and purification; reaction B: dissolving SN38 and DNPC in a solvent, adding an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing trituration and filtration; reaction C: dissolving a product obtained by reaction B in a solvent, adding a product obtained by reaction A and an organic base, and stirring at room temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction D: dissolving a product obtained by reaction C in a solvent, adding bis(p-nitrophenyl) carbonate and an organic base, and stirring at constant temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction E: dissolving a product obtained by reaction D and an amine in a solvent, adding an organic base, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification; reaction F: dissolving a product obtained by reaction E in a solvent, adding an acid, and stirring at low temperature for an appropriate time to perform a reaction; after the reaction is completed, rotating-drying the solvent, dissolving with MP2-VC-PAB-PNP in a solvent, stirring at low temperature for an appropriate time, and adding an organic base to perform a reaction; after the reaction is completed, rotating-drying the solvent, and then performing purification.
  12. The method according to any one of claims 6-11, wherein the "at low temperature" refers to in an ice water bath.
  13. The method according to any one of claims 6-11, wherein the solvent is polar solvent and/or non-polar solvent, the polar solvent is selected from the group consisting of THF, DMF, DMA, NMP and a mixture thereof; and the non-polar solvent is selected from the group consisting of dichloromethane, carbon tetrachloride and a mixture thereof.
  14. The method according to any one of claims 6-11, wherein the organic base is selected from the group consisting of N,N-diisopropylethylamine, triethylamine, pyridine, and a mixture thereof, preferably one or both of N,N-diisopropylethylamine and pyridine.
  15. The method according to any one of claims 6-11, wherein: the acid is one or two selected from the group consisting of hydrochloric acid, trifluoroacetic acid, and citric acid; or the amine is primary amine or secondary amine; or in the reaction A, the extraction is performed using ethyl acetate, and the purification is performed by column chromatography using dichloromethane and methanol as eluent; or in the reaction B, the trituration is performed using ethyl acetate, hexane, dichloromethane, or a combination thereof; or in the reaction C, the purification is performed by column chromatography using dichloromethane and methanol as eluent; or in the reaction D, the purification is performed by column chromatography using dichloromethane and methanol as eluent; or in the reaction E, the purification is performed by column chromatography using dichloromethane and methanol as eluent; or in the reaction F, the purification is performed by preparative liquid chromatography method using MeCN and 0.1% HCOOH as mobile phase A, and H 2 O and 0.1% HCOOH as mobile phase B; or the reactions are all performed under nitrogen protection.

Description

FIELD The present disclosure relates to the field of antibody-drug conjugates, and in particular to an antibody-drug conjugate intermediate and a preparation method thereof. BACKGROUND Antibody-drug conjugate (ADC), as a novel biological targeting drug, realizes a powerful combination of the targeting effect of monoclonal antibodies with the cytotoxicity of small molecular drugs, and has now become one of the fastest developing fields of tumor-targeting therapy. The three components of ADC, an antibody, a cytotoxin and a linker, together constitute a targeting drug delivery system, where the antibody provides the targeting effect, the linker ensures the stability of ADC in the process of blood transport, and the toxin exerts its killing effect on cancer cells after reaching the target. At present, there are more than 60 ADC drugs in clinical trials for antitumor therapy. Among them, most of the toxins are tubulin inhibitors, and a small part are DNA inhibitors. DNA inhibitors have two advantages over tubulin inhibitors: 1) DNA inhibitors (picomolar IC50 values) are more active than tubulin inhibitors (sub-nanomolar IC50 values), and have better effects in treating tumors with few antigens; 2) it may kill cancer cells that are not in the division phase, and has advantages in treating solid tumors. Camptothecin compounds are clinically used topoisomerase 1 (TOP1) inhibitors, and have good clinical effects on slow-growing solid tumors. However, the special structure of camptothecin leads to poor water-solubility and lipid-solubility, which thus must be modified for water-solubility. ADC drugs with camptothecin as warhead provide a new solution for the above deficiencies. At present, two ADC drugs with camptothecin derivatives as warhead have been approved for marketing, which are Enhertu (trastuzumab deruxtecan) and Trodelvy (Sacituzumab govitecan). They meet great clinical needs in treating tumors, especially malignant tumors. In Enhertu developed by AstraZeneca/Daiichi Sankyo, GGFG tetrapeptide activated by cathepsin B is used as a linker, and a small section of self-cleaved structure is introduced to release Dxd, a derivative of Exatecan. For HER2-positive metastatic breast cancer, 99 patients using Enhertu showed an objective remission rate of 54.5% and a disease control rate of 93.9%. Sacituzumab govitecan has a linker of Mcc-triazole spacer-PEG7-x-lysine-PABC, which breaks down in lysosomes (pH around 5) in cells to release camptothecin (SN38). The clinical phase II results of Sacituzumab govitecan for triple-negative breast cancer showed an effective rate as high as 30% and tumor shrinkage in 69.5% of patients, in the case that triple-negative breast cancer is almost "incurable" clinically. In addition, for small cell lung cancer in which multiple treatments had failed, Sacituzumab govitecan may shrink tumors in 60% of patients. For non-small cell lung cancer in which chemotherapy, targeting therapy and PD-1 treatment had all failed, Sacituzumab govitecan showed a control rate up to 43%. However, in clinical trials, despite the significant therapeutic effect, there are also serious safety problems caused by ADC toxicity, such as hematologic toxicity, neurotoxicity, pulmonary toxicity, skin toxicity, hepatotoxicity, ocular toxicity, metabolic abnormality, and cardiotoxicity. Therefore, improving the safety of ADC drugs is a problem that needs to be highly concerned and solved in the current drug development. In addition, there is also a problem of difficult removal of metal ion reaction products in the synthesis of the linker and load of some ADCs. For example, CL2A-SN38 used in Sacituzumab govitecan involves click chemistry reaction in the synthesis process (see Chinese Patent Application Publication No. CN102448494A, paragraph [0273] on page 50 of the specification), resulting in the presence of Cu2+ in the reaction products, which is not easily to be removed. Linker plays a vital role in the structure of ADC, and will affect the pharmacokinetic parameters, therapeutic indexes and efficacy of ADC. Different linker-camptothecin derivatives are for example disclosed in WO2021/190480. Linker can maintain the stability of ADC complex in the blood flow. For the design of linker, first the stability must be considered. Since ADC drug has a long half-life, the stability of linker is required to prevent linker from being broken down in the blood to release toxins in advance. If linker is not stable enough in the blood, it will lead to the decomposition of ADC before it enters the tumor cells, in which case the drug will have a reduced effect on tumor and even kill other cells by mistake. Moreover, in the process of internalization of ADC by tumor cells, linker should be able to release cytotoxic drugs rapidly. As a result, linker plays a significant decisive role in the safety and efficacy of the developed ADC drugs. In addition, different structures of linkers also greatly affect the difficulty factor, produc