CStone Submits Australian Trial Application for CS2009 Trispecific Antibody

CStone Pharmaceuticals, a company known for its innovative approach to biopharmaceuticals, has taken a significant step forward in the development of its anti-cancer portfolio. The Shanghai-based firm has filed a clinical trial application in Australia for its groundbreaking CS2009 antibody, marking a pivotal advance in its Pipeline 2.0 strategy. CS2009 is a trispecific antibody, targeting PD-1, VEGFA, and CTLA-4, designed to combat a variety of solid tumors.

The CS2009 antibody represents a novel approach in cancer treatment due to its unique molecular configuration. It is engineered to target three key proteins - PD-1, VEGFA, and CTLA-4 - simultaneously. This trispecific targeting allows CS2009 to preferentially bind to tumor-infiltrating T lymphocytes (TILs) that express both PD-1 and CTLA-4, while sparing CTLA-4 on cells that express it singly. This specificity is crucial as it potentially minimizes systemic toxicity without reducing therapeutic effectiveness. Moreover, CS2009 induces rapid internalization, which down-regulates PD-1 and CTLA-4 expression on TIL membranes, enhancing its efficacy.

Importantly, CS2009 maintains its VEGF inhibitory activity, a critical function for suppressing tumor growth and vascularization. Preclinical studies have shown that its anti-VEGF capabilities work synergistically with its immune checkpoint blockade, significantly boosting its anti-cancer effects. This has been evident in trials where the crosslinking with VEGFA amplifies both anti-PD-1 and anti-CTLA-4 activities, making it a highly promising candidate for treating numerous cancers, including non-small cell lung cancer, ovarian cancer, renal cell carcinoma, cervical cancer, hepatocellular carcinoma, and gastric cancer.

At the 39th Annual Meeting of the Society for Immunotherapy of Cancer in 2024, CStone showcased the preclinical data supporting CS2009's efficacy. The findings highlighted its superior anti-tumor activity compared to existing therapies, positioning CS2009 as potentially the first-in-class or best-in-class treatment option. Its capability to address diverse tumor types reinforces its role as a next-generation backbone in immuno-oncology treatments.

Dr. Jason Yang, CEO and President of Research and Development at CStone, expressed enthusiasm about the progress of CS2009. He highlighted the timely submission of the Phase I clinical trial application as a significant accomplishment for the company. Developed in-house since 2022, CS2009 has been propelled to the clinical stage through collaborative efforts within the company. Dr. Yang emphasized the importance of exploring the therapeutic benefits of CS2009, particularly for patients with tumors that do not express PD-L1 robustly and thus respond poorly to existing PD-(L)1 therapies.

CStone plans to initiate a multi-regional, first-in-human clinical trial in Australia in early 2025, with subsequent expansions planned for China and the United States. The company's strategic focus on innovative cancer treatments underscores its commitment to addressing unmet medical needs worldwide.

CStone Pharmaceuticals, established in 2015, has rapidly emerged as a leader in the development of novel anti-cancer therapies. The company's robust pipeline features a variety of promising candidates, including potentially first-in-class or best-in-class multispecific antibodies and precision medicines. With a seasoned management team, CStone continues to push the boundaries of cancer treatment, aiming to improve outcomes for patients globally.