CStone Pharmaceuticals Announces Dosing the First Patient of CS1001: China's First Fully Human, Full-length Anti-PD-L1 Monoclonal Antibody

SUZHOU, China, Oct. 20, 2017 /PRNewswire/ -- CStone Pharmaceuticals (Suzhou) Co., Ltd. announced today that the first human clinical trial of CS1001, China's first fully human and full-length anti-PD-L1 monoclonal antibody, had successfully dosed the first patient in Beijing Cancer Hospital. Subsequent patient enrollment of this Phase I trial will be carried out simultaneously in Beijing Cancer Hospital, Cancer Hospital of Fudan University and other sites.

CStone Pharmaceuticals (Suzhou) Co., Ltd. is a biopharmaceutical company focusing on the development of innovative drugs in immuno-oncology (IO). "This is another important progress since the China Food and Drug Administration (CFDA) granted Clinical Trial Application (CTA) approval to CS1001, and is another key milestone for CStone in its course of developing effective immuno-oncology drugs for cancer patients." said Dr. Frank Jiang, CEO of CStone Pharmaceuticals. "After the successful enrollment of the first patient, CStone Pharmaceuticals is now officially a clinical stage bio-pharmaceutical company. CStone will leverage its unique advantages in clinical development and a rich oncology pipeline to bring safer and more effective drugs to cancer patients in China and beyond."

Dr. Jason Yang, Chief Medical Officer of CStone further stated that, "First patient dosing of CS1001 marks the beginning of a comprehensive clinical development program by CStone for its anti-PD-L1 monoclonal antibody. Currently in China, development of drugs targeting PD-1/PD-L1 pathway is mostly concentrated on anti-PD-1 antibody. As China's first fully human, full-length anti-PD-L1 monoclonal antibody, CS1001 has the potential to be the first domestic anti-PD-L1 drug on the market. Thus, CStone has become one of the front runners in developing anti-PD-1/PD-L1 class of drugs in China. At the same time, the successful execution of the CS1001 Phase I clinical trial also lays a solid foundation for CStone to develop multiple combination therapies using anti-PD-L1 mAb as the backbone treatment in the near future."

About CS1001 clinical research

Anti-PD-L1 monoclonal antibodies have demonstrated significant anti-tumor efficacy in global clinical trials for the treatment of cancer. CS1001 (formerly code-named WBP3155), independently developed and wholly owned by CStone Pharmaceuticals, is a new anti-PD-L1 drug with completely novel molecular structure. Authorized by the U.S. based Ligand Corporation, CS1001 is also the first monoclonal antibody developed by the world leading OMT transgenic animal platform, which can generate fully human antibodies in one step. As a fully human, full-length anti-PD-L1 monoclonal antibody, CS1001 mirrors natural G-type immune globulin 4 (IgG4) human antibody, which could reduce the risk of immunogenicity and potential toxicities in patients, a unique advantage over similar drugs.

CS1001 Phase I trial is a multi-center, open label, dose escalation study to evaluate safety, pharmacokinetics, and preliminary efficacy of CS1001 for the treatment of patients with advanced cancers, including tumor types with high incidence and prevalence rates in China.

About PD-L1 monoclonal antibody

Programmed cell death ligand-1 (PD-L1) is a 40 kDa type I transmembrane protein. Under normal physiological conditions, the immune system responds to antigens in the lymph nodes or spleen by promoting the proliferation of antigen specific T cells. The interaction of programmed cell death protein-1 (PD-1) and PD-L1 can transduce inhibitory signals to reduce the proliferation of T cells and control an overreaction by the immune system, enabling the body to resume its natural immune balance. However, within the tumor microenvironment, cancer cells can up-regulate PD-L1 expression levels, directly inhibiting the body's natural antitumor immune response and allowing tumor cells to "escape" the recognition and attack by the immune system. Currently, five monoclonal antibody drugs targeting PD-1 or PD-L1 have been approved globally. In China, there are more anti-PD-1 targeting drugs being developed than anti-PD-L1. As such, clinical study of CS1001, the first fully human, full-length anti-PD-L1 monoclonal antibody in China, has significant scientific and therapeutic value.

About CStone Pharmaceuticals

CStone Pharmaceuticals is a biopharmaceutical company devoted to the development of a new generation of innovative drugs. With its broad immuno-oncology pipeline, CStone is pursuing a development strategy focusing on combination therapy. In July of 2016, CStone Pharmaceuticals announced the completion of its $150 million Series A financing, led by three prestigious VC/PE funds: Oriza Seed Venture Capital, Boyu Capital and WuXi Healthcare Ventures. All members of the management team are seasoned executives from top multinational pharmaceutical companies. CStone has successfully built up an industry leading team with clinical development and translational medicine as its core competence. This enables CStone to accelerate drug approval timeline, while at the same time, apply global standard practices to ensure clinical trial quality. The unique advantages in clinical development, funding and pipeline also positions CStone as the partner of choice for multinational pharmaceutical / biotech companies to develop drugs in China and the Asia Pacific region.

SOURCE CStone Pharmaceuticals