Core Viewpoint - Tianfeng Securities maintains a "Buy" rating for CStone Pharmaceuticals-B (02616), highlighting the initial efficacy and safety data of CS2009 (PD-1/VEGF/CTLA-4 tri-specific antibody) presented at ESMO, and anticipates further clinical and commercial potential for the tri-specific antibody [1] Group 1: Clinical Data and Efficacy - CStone Pharmaceuticals presented preliminary data from the Phase I clinical study of CS2009 at the 2025 ESMO annual meeting, with 72.2% of 72 advanced solid tumor patients still undergoing treatment as of October 19, and over 51% of patients having previously received immunotherapy, with a median follow-up period of only 1.9 months [1] - The design of the tri-specific antibody shows excellent synergistic effects, enhancing anti-tumor activity in the tumor microenvironment (TME) while avoiding interference with peripheral CTLA-4 single-positive T cells, significantly broadening the therapeutic window [2] - All dose groups observed anti-tumor activity with a dose-dependent increasing trend; with a median follow-up time of approximately 2 months, the overall response rate (ORR) was 12.2% and the disease control rate (DCR) was 71.4% [4] Group 2: Safety Profile - CS2009 demonstrated good safety at the ESMO conference, with a grade 3 or higher treatment-related adverse event (TRAE) incidence of only 13.9% and grade 3 or higher immune-related adverse event (irAE) incidence of 4.2%, with no grade 4 or 5 TRAE reported [3] - The incidence of grade 3 or higher TRAE and TRAE leading to treatment discontinuation was significantly lower than other immuno-oncology (IO) dual antibodies and combination therapies, indicating a safety advantage for CS2009 [3] Group 3: Future Development Plans - The global multi-center Phase I/II clinical trial for CS2009 has been initiated, with the first patient enrolled in Australia, and more data expected to be presented at the ASCO conference in Q2 2026 [4] - The Phase III registration clinical plan is expected to start in 2026, targeting various indications including first-line non-small cell lung cancer (NSCLC) and other solid tumors in combination with standard chemotherapy regimens [4]