On February 15, 2026 CStone Pharmaceuticals ("CStone," HKEX: 2616), an innovation-driven biopharmaceutical company focused on the research and development of therapies for oncology, autoimmune/inflammation, and other key disease areas, reported that the U.S. FDA has cleared the IND application to initiate a Phase II clinical trial of its core asset, CS2009, in patients with advanced solid tumors.
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Dr. Jason Yang, CEO, President of R&D, and Executive Director at CStone, stated, "We are pleased to receive FDA clearance to proceed with the global Phase II clinical trial of CS2009. This milestone follows a productive interaction with the agency, during which they reviewed our comprehensive Phase I data—including safety and antitumor activity data collected during dose escalation and expansion—and provided alignment on key elements of the Phase II study design, including dose optimization and expansion strategies. We are now actively advancing CS2009 clinical program globally and look forward to sharing further updates as the study progresses."
About CS2009 (PD-1/VEGF/CTLA-4 Trispecific Antibody)
CS2009, an innovative trispecific antibody designed and developed by CStone, with the potential to be first- or best-in-class. It combines three clinically validated targets—PD-1, VEGFA, and CTLA-4—and exerts multidimensional anti-tumor effects through synergistic actions. Specifically, anti-PD-1 activity reverses T cell exhaustion, anti-CTLA-4 activity promotes T cell activation and proliferation, while anti-VEGFA activity blocks tumor angiogenesis and improves the tumor micro-environment (TME). In the TME, anti-PD-1 and anti-CTLA-4 activities are significantly enhanced by crosslinking with VEGFA. Meanwhile, CS2009 preferentially blocks PD-1 and CTLA-4 on double-positive tumor-infiltrating T cells while minimizing interference with CTLA-4 regulation in peripheral T cells.
The ongoing global, multicenter Phase II clinical trial of CS2009 features a multi-cohort, parallel expansion design to evaluate the efficacy, safety, tolerability, and pharmacokinetics/pharmacodynamics (PK/PD) of CS2009 as monotherapy and combination regimens. The study comprises 15 monotherapy and combination therapy cohorts across 9 solid tumor indications, including NSCLC, CRC, TNBC, ES-SCLC, PROC, cervical cancer (CC), hepatocellular carcinoma (HCC), gastric or gastroesophageal junction cancer (GC/GEJC), and esophageal squamous cell carcinoma (ESCC). The trial is actively enrolling patients in Australia and China and has received IND clearance in the U.S.
(Press release, CStone Pharmaceauticals, FEB 15, 2026, View Source [SID1234662683])