CStone Pharmaceuticals-B (02616) saw its gains expand to over 20% by late morning. At the time of writing, the stock was up 20.29%, trading at HK$8.30, with a turnover of HK$390 million.

The company announced the latest clinical progress of its self-developed PD-1/VEGF/CTLA-4 trispecific antibody, CS2009. Preliminary efficacy data from the Phase I/II trial of CS2009 as a monotherapy for lung cancer were positive. In first-line non-small cell lung cancer (NSCLC) patients with a PD-L1 tumor proportion score (TPS) ≥50%, the objective response rate (ORR) reached 90%, and the disease control rate (DCR) was 100%. Among immunotherapy (IO) pretreated, driver gene (AGA) negative second-line and later-line NSCLC patients, the ORR was 25%.

Based on these results, CStone Pharmaceuticals plans to initiate the first Phase III global multi-center clinical trial (MRCT) for CS2009 by the end of 2026, focusing on indications such as NSCLC, colorectal cancer (CRC), and small cell lung cancer (SCLC). Further Phase I and Phase II clinical research data for CS2009 are expected to be presented in 2026 at the American Society of Clinical Oncology (ASCO) Annual Meeting and/or the European Society for Medical Oncology (ESMO) Congress.