Mabwell (688062.SH, 02493.HK), an innovation-driven biopharmaceutical company with a fully integrated industry chain, will present multiple clinical study results of its novel Nectin-4-targeting ADC 9MW2821 (Bulumtatug Fuvedotin, BFv) at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, including the Phase Ib/II clinical study data of 9MW2821 in combination with toripalimab for locally advanced or metastatic urothelial carcinoma (la/mUC) in the form of oral presentation, and the Phase II clinical study data of 9MW2821 in combination with toripalimab for perioperative muscle-invasive bladder cancer (MIBC) in the form of poster presentation.

The Phase Ib/II clinical study of 9MW2821 in combination with toripalimab for the treatment of patients with la/mUC enrolled a total of 52 patients with advanced urothelial carcinoma. Follow-up results showed that as of December 1, 2025, 47 subjects were included in the efficacy analysis. The overall objective response rate (ORR) was 83.0%, confirmed ORR was 74.5%, complete response (CR) rate was 12.8%, and disease control rate (DCR) was 89.4%; and for the previously untreated populations, ORR was 87.5%, confirmed ORR was 80.0%, CR rate was 12.5% and DCR was 92.5%. The median progression-free survival (PFS) was 12.9 months, median duration of response (DoR) and median overall survival (OS) was not yet reached. No new safety signals related to 9MW2821 or toripalimab were observed in this study.

The Phase II clinical study on 9MW2821 in combination with toripalimab for patients with perioperative MIBC enrolled a total of 32 subjects. As of January 4, 2026, 7 subjects completed neoadjuvant therapy (9MW2821 in combination with toripalimab). Among these subjects, 6 subjects completed radical cystectomy and regional lymph node dissection, and 1 subject refused radical surgery due to achieving clinical CR following neoadjuvant therapy. Pathological complete response (pCR) was 66.7% (4/6), and pathological downstaging (pDS) rate was 83.3% (5/6). No new safety signals related to 9MW2821 or toripalimab were observed in this study.

About 9MW2821

9MW2821 is a novel Nectin-4-targeting ADC independently developed by Mabwell based on its ADC development platform. Mabwell is currently conducting multiple clinical studies for several indications including urothelial carcinoma, cervical cancer, esophageal cancer and breast cancer. It is the world’s first Nectin-4 ADC to enter Phase III clinical trials for cervical cancer (CC) and triple-negative breast cancer (TNBC). Four pivotal Phase III clinical studies are underway. 9MW2821 has obtained FDA Fast Track Designation for three indications, Orphan Drug Designation for one indication, and Breakthrough Therapy Designation from the CDE of NMPA for two indications.

Interim analysis for the Phase III clinical trials of urothelial carcinoma (UC) monotherapy, UC combination therapy and CC monotherapy are planned to be conducted in 2026, and Applications for pre-NDA meetings are expected to be submitted to the Center for Drug Evaluation under the National Medical Products Administration based on the data of interim analysis. Phase Ib/II clinical trial of CC combination therapy is planned to be completed in the second half of 2026, followed by a Phase III clinical trial to be initiated.