Mabwell (688062.SH), an innovation-driven biopharmaceutical company with entire industry chain, announced multiple clinical research results to be presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, including phase Ib/II clinical study data of 9MW2821 (Bulumtatug Fuvedotin, BFv), a novel Nectin-4 targeting ADC, in combination with Toripalimab in locally advanced or metastatic uroepithelial carcinoma to be presented as oral presentation, and clinical study data of 7MW3711 and 9MW2921, a novel B7-H3 targeting ADC and a novel Trop-2 targeting ADC respectively, to be presented as poster presentations. The study of 9MW2821 was the only selected Chinese oral presentation in the field of urothelial carcinoma at this meeting. 

Nectin-4 ADC (9MW2821):

In the phase Ib/II clinical study of 9MW2821 in combination with Toripalimab for the treatment of patients with locally advanced or metastatic urothelial carcinoma (la/mUc), a total of 40 patients with previously untreated for la/mUC were enrolled in the study and were treated with 9MW2821 (1.25 mg/kg) and Toripalimab (240 mg).

As of December 19, 2024, the objective response rate (ORR) was 87.5% and the confirmed ORR was 80%. The disease control rate (DCR) was 92.5%. Median progression-free survival (PFS) and duration of response (DoR) have not been achieved. No new safety signals of 9MW2821 or Toripalimab were observed in this study.

9MW2821 stands out as the first clinical-stage drug candidate among Chinese companies for this specific target. And it’s the first Nectin-4 targeting ADC to disclose clinical efficacy data in cervical, esophageal, and breast cancers. Currently, 3 Phase III pivotal clinical trials are ongoing. Its monotherapy and combination therapy with Toripalimab for urothelium carcinoma have been granted Breakthrough Therapy Designation (BTD) by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) in China. It has also been granted Fast Track Designations (FTD) for 3 indications and Orphan Drug Designation (ODD) for 1 indication by the U.S. Food and Drug Administration (FDA).

B7-H3 ADC (7MW3711):

7MW3711 has enrolled 43 patients as of January 2, 2025 in a phase I/II clinical study in patients with advanced solid tumors. During the dose-escalation phase, dose-limiting toxicity (DLT) was not observed and the maximum tolerated dose (MTD) has not been reached. In patients evaluated at doses of 4.5 mg/kg or higher, the ORR for esophageal cancer, ovarian cancer, and prostate cancer was 33.3%, 60.0%, and 50.0%, respectively, and the DCR was 100%.

In the phase I/II clinical study in lung cancer patients, 37 lung cancer patients were enrolled as of January 8, 2025, including 16 small cell lung cancer (SCLC) patients and 21 non-small cell lung cancer (NSCLC) patients. Common grade ≥3 adverse reactions were neutrophil count decreased, white blood cell count decreased, anemia, lymphocyte count decreased, and platelet count decreased. Among the 25 patients who received 7MW3711 at a dose of 4.5 mg/kg or greater and completed at least one tumor evaluation, the ORR was 36.0% and the DCR was 96.0%; of these, the ORR and DCR were 62.5% and 100.0%, respectively, for patients with small-cell lung cancer at a dose of 4.5 mg/kg. Among squamous lung cancer (Sq-NSCLC) patients with a B7-H3 H-score >5, the ORR and DCR were 37.5% and 87.5%, respectively.

The study results suggest that 7MW3711 has a tolerable safety profile and good anti-tumor activity in patients with advanced tumors such as lung, esophageal, prostate and ovarian cancers.

7MW3711 was developed with Mabwell's Interchain-Disulfide Drug Conjugate (IDDC™) platform. It consists of an innovative antibody molecule, a novel linker, and a novel payload: Mtoxin™, which is a topoisomerase I inhibitor. It has been granted ODD by the FDA for the treatment of SCLC.

Trop-2 ADC (9MW2921):

In the first-in-human clinical study in patients with advanced solid tumors, a total of 39 patients were enrolled as of November 12, 2024. The most common ≥3 grade adverse were stomatitis, anemia, white blood cell count decreased, neutropenia, lymphocyte count decreased, etc. The ORR of 3.0 mg/kg dose group was 42.1% and the DCR was 84.2%. Under this dose level, the ORR and DCR was 75% and 100% for endometrial cancer, 50% and 75% for HR+/HER2- breast cancer, 50% and 100% for gastric cancer, 25% and 100% for non-squamous non-small cell lung cancer.

The study result suggests that 9MW2921 has a tolerable safety profile and good anti-tumor activity in patients with advanced tumors.

9MW2921 was developed with Mabwell's Interchain-Disulfide Drug Conjugate (IDDC™) platform. It consists of an innovative antibody molecule, a novel linker, and a novel payload: Mtoxin™, which is a topoisomerase I inhibitor.