China's First Fully Human, Full-length Anti-PD-L1 Monoclonal Antibody Receives Approval to Initiate Clinical Trials by the China Food and Drug Administration

SHANGHAI, July 17, 2017 /PRNewswire/ -- CStone Pharmaceuticals today announced that it has received Clinical Trial Application (CTA) approval from the China Food and Drug Administration (CFDA) to conduct clinical trials in China with the investigational agent CS1001, which is China's first fully human, full-length anti-PD-L1 monoclonal antibody to successfully enter the clinical development stage.

After eight months of review, the CFDA granted CTA approval to CS1001, the first fully human anti-PD-L1 monoclonal antibody generated by the world leading OMT transgenic animal platform. CS1001 is independently developed and wholly owned by CStone Pharmaceuticals. As a fully human, full-length antibody that mirrors natural human IgG, CS1001 reduces the risk of immunogenicity and potential toxicities in patients. CStone Pharmaceuticals is initiating Phase 1 clinical trials in patients with advanced cancer. Planned indications include those tumor types with high incidence and prevalence rates in China.

"I am very pleased that CStone's first IND application is approved by the CFDA, allowing us to initiate clinical trials in China. This event is a significant milestone for the company," said Dr. Frank Jiang, CEO of CStone Pharmaceuticals. Dr. Jiang further explains that this approval lays a solid foundation for subsequent development of multiple combination therapies using anti-PD-L1 as the backbone treatment. CStone will leverage its unique advantages in clinical development and rich oncology pipeline to bring significant clinical benefit to cancer patients in China and beyond.

Immuno-oncology, led by PD-1 / PD-L1 checkpoint inhibitors and with its proven breakthrough therapeutic effects in a wide range of tumors, signifies a new era for cancer therapies worldwide. Currently, five anti-PD-1 / PD-L1 drugs are approved by the U.S. FDA in more than 10 indications, but none has been approved in China. As such, CStone's CS1001 has the potential to address the urgent needs of Chinese patients for this class of drugs.

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.

About CS1001

CS1001 (formerly codenamed WBP3155), independently developed and wholly owned by CStone Pharmaceuticals, is the first fully human, full-length innovative anti-PD-L1 drug candidate in China. 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.

About PD-L1

Programmed cell death ligand-1 (PD-L1) is a 40kDa 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.

SOURCE CStone Pharmaceuticals