Mabwell's B7-H3-Targeting ADC 7MW3711 Shows Promising Efficacy in Advanced Solid Tumors
Key Insights
Mabwell (search)'s novel B7-H3 (search)-targeting ADC 7MW3711 demonstrated encouraging clinical activity in a phase I/II study of 74 patients with advanced solid tumors.
The drug achieved notable response rates in esophageal cancer (42.9% ORR) and lung cancers, with small cell lung cancer showing 50.0% ORR and squamous NSCLC achieving 38.5% ORR.
No dose-limiting toxicities were observed during dose escalation, and the maximum tolerated dose has not yet been reached, indicating a favorable safety profile.
Mabwell (search)'s investigational B7-H3 (search)-targeting antibody-drug conjugate (ADC) 7MW3711 has demonstrated encouraging clinical activity across multiple advanced solid tumor types in an ongoing phase I/II study. The Shanghai-based biopharmaceutical company announced that clinical results from 74 enrolled patients will be presented at the European Society for Medical Oncology (ESMO) Congress 2025.
Clinical Efficacy Results
As of September 15, 2025, among 54 patients treated at doses of 4.0 mg/kg or above who reached tumor assessment, 19 partial responses (PRs) or complete responses (CRs) were observed. The drug showed particularly promising activity in esophageal cancer, where 7 patients treated at 4.0 mg/kg or above achieved an objective response rate (ORR) of 42.9% and a disease control rate (DCR) of 100%.
In lung cancer patients treated at the 4.0 mg/kg every two weeks (Q2W) regimen, 7MW3711 demonstrated notable efficacy across different histological subtypes. Small cell lung cancer (SCLC) patients achieved an ORR of 50.0% with a DCR of 90.0%, while patients with squamous non-small cell lung cancer (Sq-NSCLC) showed an ORR of 38.5% and DCR of 92.3%.
Safety Profile
The safety data from the dose escalation phase revealed no dose-limiting toxicities (DLTs), and the maximum tolerated dose (MTD) has not yet been reached. The most common Grade ≥3 treatment-emergent adverse events (TEAEs) were hematological in nature, including decreased white blood cell count, neutrophil count, anemia, lymphocyte count, and platelet count.
Drug Characteristics and Development
7MW3711 is characterized by its stable structure, homogeneous composition, and high purity, making it suitable for industrial scale-up. The ADC utilizes a novel camptothecin payload, which demonstrated 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.
The drug's payload is released through tumor tissue protease hydrolysis, enhancing systemic stability in humans. In safety evaluation models including cynomolgus monkeys, 7MW3711 demonstrated good safety profile and pharmacokinetic properties. Compared with ADCs in the same class worldwide, 7MW3711 has shown better tumor killing effects in multiple animal tumor models.
Therapeutic Target and Market Potential
Given the expression profile and distribution of B7-H3 (search), ADCs targeting this antigen 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.
The clinical results suggest encouraging efficacy of 7MW3711 in advanced solid tumors, particularly in esophageal and lung cancer, positioning the drug as a potential treatment option for patients with limited therapeutic alternatives.