Mabwell (688062.SH), an innovative biopharmaceutical company with entire industry chain, announced that clinical research results of its novel B7-H3-targeting ADC (R&D code: 7MW3711) for multiple advanced solid tumors, will be presented as a poster at the European Society for Medical Oncology (ESMO) Congress 2025.

As of Sep. 15, 2025, 74 patients with advanced solid tumor were enrolled and treated with 7MW3711 in the phase I/II study. Among 54 patients treated at 4.0 mg/kg or above and reaching tumor assessment, 19 partial responses (PRs) or complete responses (CRs) were observed. 7 patients with esophageal cancer (EC) were enrolled at 4.0 mg/kg or above and achieved an objective response rate (ORR) of 42.9% and a disease control rate (DCR) of 100%. Among lung cancer patients treated at the 4.0 mg/kg Q2W and reaching tumor assessment, the ORR for small cell lung cancer (SCLC) and squamous non-small cell lung cancer (Sq-NSCLC) were 50.0% and 38.5% respectively, with DCR of 90.0% and 92.3% respectively.

No dose-limiting toxicities (DLTs) were observed in the dose escalation phase, and the maximum tolerated dose (MTD) has not yet been reached. The most common Grade ≥3 TEAEs were white blood cell (WBC) count decreased, neutrophil count decreased, anemia, lymphocyte count decreased, platelet count decreased.

The study results suggest encouraging efficacy of 7MW3711 in advanced solid tumors, especially in esophageal and lung cancer.

About 7MW3711

7MW3711 is a novel B7-H3-targeting ADC independently developed by Mabwell. Given the expression profile and distribution of B7-H3, ADCs targeting B7-H3 hold promising therapeutic potential for cancers with significant unmet medical needs, including lung cancer, sarcoma, prostate cancer, head and neck cancer, and esophageal carcinoma, indicating broad market prospects.

7MW3711 is pharmaceutical characterized as stable structure, homogeneous composition, high purity, and it is suitable for industrial scale-up. Compared with ADCs in the same class worldwide, 7MW3711 has shown better tumor killing effects in multiple animal tumor models. 7MW3711 utilizes a novel camptothecin payload, which demonstrates stronger antitumor activity than DXd payloads in preclinical studies. Developed with site-specific conjugation technology, 7MW3711 is a homogeneous ADC with a drug-antibody ratio of 4, ensuring optimal stability and batch-to-batch consistency. Its payload is released through tumor tissue protease hydrolysis, further enhancing systemic stability in humans. In the safety evaluation model of animals including cynomolgus monkeys, 7MW3711 demonstrated good safety profile and pharmacokinetic properties.