Biopharmaceutical company CStone Pharmaceuticals (HKEX:2616) announced on Monday that it has submitted a clinical trial application in Australia for CS2009, a trispecific antibody targeting PD-1, VEGFA and CTLA-4, aimed at treating various solid tumours.

The first-in-human study has been registered on Clinicaltrials.gov (NCT06741644). CS2009's innovative design enables simultaneous targeting of PD-1 and CTLA-4, selectively enhancing tumour-infiltrating T lymphocytes (TILs) while sparing single-positive cells to reduce systemic toxicity. It also promotes rapid internalization, leading to reduced PD-1 and CTLA-4 expression on TILs.

Preclinical data suggest significant synergy between CS2009's anti-VEGF and immune checkpoint inhibitory activities. At the 39th Annual Meeting of the Society for Immunotherapy of Cancer, CStone presented compelling data demonstrating CS2009's superior anti-tumour efficacy over potential competitors. CS2009 shows promise across a broad range of cancers, including non-small cell lung cancer, ovarian cancer, renal cell carcinoma, cervical cancer, hepatocellular carcinoma, and gastric cancer. With its differentiated approach, CS2009 is positioned as a potential first- or best-in-class immuno-oncology treatment.