YZYBIO-B (02496) announced that on January 31, 2026, the Investigational New Drug (IND) application for Recombinant Anti-EpCAM and CD3 Human-Mouse Chimeric Bispecific Antibody for Injection (M 701) was approved by the U.S. Food and Drug Administration (FDA). This milestone signifies that this innovative therapy for Malignant Pleural Effusion (MPE) has entered a new phase of international clinical development, offering new hope for patients worldwide. Malignant pleural effusion is a common and serious complication of malignant tumors, frequently observed in patients with advanced lung or breast cancer; current treatments remain predominantly palliative, creating a pressing clinical need for innovative strategies to address this gap. M 701 precisely targets EpCAM and CD3: EpCAM is highly expressed in tumor cells of epithelial-origin malignant pleural effusions, making it a key therapeutic target, while CD3 activates the body's anti-tumor immune response, with the two working synergistically to achieve targeted treatment. The approved clinical trial is an open-label, multi-center, Phase Ib/II study designed to evaluate the safety, efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity of intrapleural infusion of M 701 in patients with malignant pleural effusion caused by advanced epithelial tumors.