YZYBIO-B(02496): The mid-term study data of malignant pleural effusion Ib phase of M701 will be presented at the 2024 ESMO conference.

YZYBIO-B(02496) announced that the mid-term analysis data of the Phase Ib clinical study of the investigational bispecific antibody drug M701 targeting epithelial cell adhesion molecule and cluster of differentiation 3 for the treatment of malignant pleural effusion caused by advanced non-small cell lung cancer conducted in China has been presented in the form of a poster discussion at the 2024 European Society for Medical Oncology (ESMO) Annual Meeting (Poster number: 1371P). This study is a multicenter, open-label Phase Ib clinical trial (development code: M70103) for malignant pleural effusion caused by advanced non-small cell lung cancer. The study enrolled advanced non-small cell lung cancer patients who have failed first-line treatment and have symptomatic pleural effusion. The patients received pleural infusion of M701 after thoracentesis drainage, with a dose and frequency of 25g M701 on Day 1, followed by different doses of M701 (50-400g) on Days 4, 7, and 10 (additional dosing on Days 13 and 16 in the extension phase for the 6-dose group), to determine the optimal dose for the Phase II study. The primary endpoint of the study was the safety and tolerability of pleural infusion of M701, determining the recommended Phase II dose, with secondary endpoints including pleural effusion response data and immunogenicity. Safety results: As of April 19, 2024, 24 subjects have been enrolled in the study, including 11 subjects in the dose escalation phase and 13 subjects in the extension phase. No dose-limiting toxicities (DLT) were observed in the dose escalation phase. The recommended Phase II dose (RP2D) was determined to be 400g (maintenance dose) administered 4 times. There were no study drug-related serious adverse events (SAE) during the study, with only one Grade 3 treatment-related adverse event (TRAE), neutropenia. The safety evaluation of pleural infusion with M701 was favorable. Efficacy results: In the Phase Ib, M701 demonstrated good control of pleural effusion. Among the 13 subjects in the extension phase, the objective response rate and pleural effusion control rate at Week 4 of enrollment were both 61.5%. The objective response rate at Week 8 was still 53.8%, with a pleural effusion control rate of 61.5%. At the end of the Phase Ib study, the median puncture-free survival (mPuFS) reached 237 days. Tumor cell detection in pleural effusion also showed a significant decrease in EpCAM-positive tumor cells after three injections of M701 into the pleural cavity compared to baseline. Based on the favorable safety and efficacy results mentioned above, the company is actively progressing with the Phase II clinical study for malignant pleural effusion. This study is a randomized controlled trial comparing the effectiveness and safety of pleural infusion with M701 or cisplatin in controlling malignant pleural effusion in non-small cell lung cancer patients.