CStone Pharmaceuticals (HKEX: 2616) reported that the U.S. Food and Drug Administration (FDA) has cleared the Investigational New Drug (IND) application for CS2009 (PD-1/VEGF/CTLA-4 trispecific antibody) to commence a Phase II clinical trial in advanced solid tumors.

CS2009 is designed to combine three established targets—PD-1, VEGFA, and CTLA-4—to achieve multiple antitumor effects. Initial Phase I results, presented at the 2025 European Society for Medical Oncology annual meeting, reportedly showed a favorable safety profile alongside encouraging antitumor activity. The ongoing global multicenter Phase II study aims to assess monotherapy and combination therapy regimens across 15 cohorts covering 9 solid tumor types. Patient enrollment is currently underway in Australia and China, with investigational new drug clearance now in place for the United States.

According to the announcement, the expansion strategy for Phase II was shaped by discussions with the FDA, with key elements including optimized dosing and targeted tumor populations. The company also highlighted that four innovative drugs have been launched to date and that there are 16 candidates in its pipeline. Cautionary statements in the announcement underscore that no guarantee can be made regarding the future success of CS2009, and the financial figures included have not been audited or reviewed. The disclosure advises shareholders and investors to remain prudent when considering any securities of the company.