Zhijing Finance APP news, Youche Enzyme-B (02496) announced that the in-development specific dual-specificity antibody drug M701 targeting epithelial cell adhesion molecule and differentiation cluster 3, independently developed by the company, has had its mid-term analysis data of phase Ib clinical trial for treating malignant pleural effusion caused by advanced non-small cell lung cancer in China presented in the form of a poster discussion at the 2024 European Society for Medical Oncology (ESMO) Annual Meeting (Poster No.: 1371P).

This study is a multicenter, open-label phase Ib clinical trial (R&D code: M70103) targeting malignant pleural effusion caused by advanced non-small cell lung cancer. The study includes patients with symptomatic pleural effusion from advanced non-small cell lung cancer who have failed first-line treatment. While maintaining systemic treatment, M701 drug is administered through thoracentesis after chest tube drainage. The drug dosage and frequency are as follows: infused with 25μg of M701 on the 1st day, infused with different doses of M701 (50-400μg) on the 4th, 7th, and 10th days (additional dosing on the 13th and 16th days in the extension phase 6 needles group), after determining the optimal dose, entering the II phase study. The study's primary endpoint is the safety and tolerability of thoracic infusion of M701, determining the recommended phase II dose, secondary endpoints include pleural effusion efficacy data and immunogenicity.

Safety results: As of April 19, 2024, 24 subjects have been enrolled in the study, including 11 participants in the dose escalation phase and 13 in the extension phase. In the dose escalation phase, no DLT (dose-limiting toxicity) events occurred. Eventually, the RP2D dose was determined to be 400μg (maintenance dose) administered 4 times, entering the II phase study. No study drug-related SAEs (serious adverse events) occurred during the study period, with only one grade 3 TRAE (treatment-related adverse event) of neutropenia. M701 thoracic infusion demonstrated good safety.

Efficacy results: In the Ib phase, M701 showed good control of pleural effusion. Among the 13 subjects in the extension phase, the objective response rate and pleural metastasis locking rate at the 4th week of enrollment were both 61.5%. The objective response rate at the 8th week of enrollment could still reach 53.8%, and the pleural metastasis locking rate could be maintained at 61.5%. By the end of the Ib phase study, the median puncture-free survival (mPuFS) reached 237 days. Tumor cell detection results in pleural effusion also suggest a significant decrease in EpCAM-positive tumor cells after three chest infusions of M701 compared to baseline.

Based on the above good safety and efficacy results, the company is actively advancing the Phase II clinical study of malignant pleural effusion. This study is a randomized controlled trial comparing the effectiveness and safety of thoracic infusion of M701 or cisplatin in controlling malignant pleural effusion in patients with non-small cell lung cancer.