MABWELL-B (02493.HK): Phase II Data for 9MW2821 in TNBC to Be Presented at ESMO 2026; ORR 30.0%

NewTimeSpace News: On 19 October 2026, Mabwell (Shanghai) Bioscience Co., Ltd. (the "Company") published an overseas regulatory announcement reproducing its voluntary disclosure published on the website of the Shanghai Stock Exchange. At the 2026 European Society for Medical Oncology (ESMO) Congress to be held in Madrid, Spain from 23 to 27 October 2026, the Company will present, in an oral presentation, Phase II clinical data for its Nectin-4-targeting ADC 9MW2821 in patients with locally advanced or metastatic triple-negative breast cancer (TNBC) previously treated with an ADC carrying a topoisomerase I inhibitor payload.

The announcement disclosed that, as of 10 April 2026, among 60 efficacy-evaluable patients, the objective response rate (ORR) was 30.0%, the disease control rate (DCR) was 80.0%, median progression-free survival (mPFS) was 3.7 months, median duration of response (mDOR) was 8.7 months and median overall survival (mOS) had not matured; no new safety signals were observed during the follow-up period. The results indicate that 9MW2821 has a manageable safety profile and positive therapeutic effects in triple-negative breast cancer patients.

The Company stated that 9MW2821 is Mabwell's first site-specific conjugated ADC targeting Nectin-4, with site-specific antibody modification achieved through its proprietary conjugation linker and optimised ADC conjugation process; after administration it binds to Nectin-4 on tumour cells, enters the cells and releases cytotoxic agents via enzymatic cleavage for precise tumour killing. 9MW2821 has been studied in multiple clinical trials across indications including urothelial carcinoma (UC), cervical cancer (CC), TNBC and oesophageal cancer (EC), with cumulative enrolment exceeding 2,200 patients; the Company is advancing four Phase III pivotal registration trials, of which the UC monotherapy and combination therapies have been included in China's breakthrough therapy designation list, and the CC monotherapy is the world's first same-target drug to enter Phase III trials.