CStone Pharmaceuticals, a leading biopharmaceutical company focused on the research, development, and commercialization of innovative immuno-oncology therapies and precision medicines, and Jiangsu Hengrui Pharmaceuticals today announced a strategic partnership and exclusive licensing agreement on anti-CTLA-4 mAb CS1002 in the Greater China region. This strategic partnership marks another milestone in CStone's mission to introduce innovative oncology therapies in China after the commercial launch of two first-in-class drugs this year.

Under the terms of the agreement, CStone will be eligible for an upfront payment and potential milestone payments up to $200 Mn in addition to double-digit royalties. Hengrui will obtain the exclusive rights for research, development, registration, manufacturing, and commercialization of anti-CTLA-4 mAb CS1002 in Greater China. CStone will retain the rights to develop and commercialize of CS1002 outside of Greater China.

Cytotoxic T lymphocyte associated antigen 4 (CTLA-4) is one of the few clinically validated targets for IO combination therapies. There is only one anti-CTLA-4 monoclonal antibody approved globally, and it is also approved in China. According to EvaluatePharma, the annual global revenue of the product in 2020 was approximately $1.69 billion. CS1002 is an investigational anti-CTLA-4 monoclonal antibody being developed by CStone currently in clinical development. Results from the ongoing Ph1a/1b study showed that differentiated dosing schedules of CS1002 in combination with CS1003 (anti-PD-1) were well-tolerated and demonstrated very encouraging efficacy in anti-PD-(L)1-refractory melanoma, anti-PD-(L)1-refractory hepatocellular carcinoma, and anti-PD-(L)1-naïve, pretreated microsatellite instability high/deficient mismatch repair (MSI-H/dMMR) tumors.

Dr. Frank Jiang, Chairman and CEO of CStone, said, "We are happy to reach the partnership with Hengrui. As a leading global China pharmaceutical company with an extensive oncology pipeline and strong integrated capabilities in commercialization, we are very confident that Hengrui will bring the full potentialities of CS1002 into the Greater China market. Through this collaboration, we believe we will join forces to bring forward more high-quality innovative oncology therapies to patients."

Dr. Lianshan Zhang, Member of the Board, Senior Vice President and President of global R&D of Hengrui, said, "We are happy to enter into this collaboration with CStone on the backbone immune-oncology asset of CS1002. With its combination therapy potential, CS1002 will further synergize our pipeline, enrich the oncology portfolio and strengthen our competitiveness. As a leading Chinese biopharmaceutical company, CStone has demonstrated its outstanding research and development capabilities with impressive early-stage clinical data and differentiated dosing schedules of CS1002. We have full confidence in the future development of it to provide more innovative drugs for Chinese patients."