MABWELL-B(02493): Will present 9MW2821 clinical data as an oral presentation at the 2026 European Society for Medical Oncology (ESMO) Congress

MABWELL-B(02493) announced that the Company will present Phase II clinical study data for its innovative Nectin-4-targeting ADC drug in patients with locally advanced or metastatic triple-negative breast cancer (TNBC) who have previously received ADC therapy with a topoisomerase I inhibitor payload, as an oral presentation at the 2026 European Society for Medical Oncology (ESMO) Congress to be held in Madrid, Spain, from October 23 to October 27, 2026: As of April 10, 2026, among 60 efficacy-evaluable patients, the objective response rate (ORR) was 30.0%, the disease control rate (DCR) was 80.0%, the median progression-free survival (mPFS) was 3.7 months, the median duration of response (mDOR) was 8.7 months, and the median overall survival (mOS) had not yet matured. No new safety signals were observed during this follow-up period. 9MW2821 is Mabwell's first site-specific conjugated ADC novel drug targeting Nectin-4 and an innovative candidate developed by the Company using its ADC drug development platform, achieving site-specific antibody modification through a conjugation linker with independent intellectual property rights and an optimized ADC conjugation process. After administration, 9MW2821 can bind to Nectin-4 on the surface of tumor cells and enter the cells, where it directionally releases cytotoxic agents through enzymatic cleavage, thereby achieving precise killing of tumors. 9MW2821 has now been studied in multiple clinical trials across indications including urothelial carcinoma (UC), cervical cancer (CC), triple-negative breast cancer (TNBC), and esophageal cancer (EC), with cumulative clinical enrollment exceeding 2,200 patients. The Company is currently advancing four Phase III pivotal registrational clinical trials, covering UC monotherapy and combination therapy, CC monotherapy, and TNBC (post topoisomerase I inhibitor payload ADC) monotherapy, among which UC monotherapy and combination therapy have successively been included in the national Breakthrough Therapy Designation list, CC monotherapy is the world's first drug against the same target to enter Phase III clinical studies, and the corresponding TNBC therapy is also the world's first candidate for the same indication to enter this development stage, possessing outstanding industry competitive advantages. The project is concurrently rapidly conducting multiple Phase I/II clinical trials: TNBC combination therapy, UC perioperative combination therapy, and EC monotherapy are in Phase II; EC combination therapy and CC combination therapy are in Phase Ib/II; and in terms of overseas development, the TNBC (post topoisomerase I inhibitor payload ADC) monotherapy has entered Phase Ib in the United States. According to the Company's R&D plan, interim analyses of the Phase III clinical trials of 9MW2821 for UC monotherapy, combination therapy, and CC monotherapy will be conducted in 2026, and based on the interim analysis data, the Company expects to submit a pre-New Drug Application meeting request to the Center for Drug Evaluation of the National Medical Products Administration.