Pralsetinib Is Expected to be China’s First Approved RET Inhibitor

（SUZHOU, China, September 7th, 2020）CStone Pharmaceuticals (SUZHOU) Co., Ltd.（“CStone”, HKEX: 2616) announced that China’s National Medical Products Administration (NMPA) has accepted the company’s New Drug Application (NDA) for pralsetinib for the treatment of RET fusion-positive non-small cell lung cancer (NSCLC) patients previously treated with platinum-based chemotherapy. Developed by CStone’s partner, Blueprint Medicines, pralsetinib is an investigational, highly potent and selective drug targeting oncogenic RET alterations, including predicted resistance mutations. Pralsetinib showed deep and durable anti-tumor activity with a well-tolerated safety profile in the Chinese cohort of patients with RET fusion-positive NSCLC previously treated with platinum-based chemotherapy. These results were consistent with previously reported data in the global patient population of the ARROW study.

A principal investigator of the ARROW study, Professor Wu Yilong from the Guangdong Provincial People's Hospital, said, “In the field of lung cancer precision medicine, following targets such as EGFR, ALK, ROS1 and NTRK, the research and development of a selective treatment that targets RET-driven NSCLC is another huge breakthrough. At present, there is no approved selective RET inhibitor in China, representing a huge unmet medical need for RET fusion-positive NSCLC patients. The global trial of pralsetinib as well as the Chinese cohort of patients with NSCLC yielded exciting results, and we are looking forward to potentially making this agent available to benefit this group of patients.”

Dr. Frank Jiang, Chairman and CEO of CStone, noted, “We are pleased to see that the NMPA has accepted the company’s NDA for pralsetinib with the priority review designation for the treatment of RET fusion-positive NSCLC patients previously treated with platinum-based chemotherapy. This is the third NDA submitted by CStone globally and the second in mainland China in 2020, which reflects that CStone Pharmaceuticals is accelerating its commercialization strategy transformation. We are looking forward to domestic marketing of the agent pending regulatory review and bringing new hope to RET fusion-positive NSCLC patients in China.”

Dr. Jason Yang, Chief Medical Officer of CStone, commented, “We are glad to see that pralsetinib showed rapid and durable anti-tumor activity and was well-tolerated in clinical trials. From the time that we entered into our collaboration with Blueprint Medicines, which enabled us to develop and commercialize pralsetinib in Greater China, to successfully submitting the NDA in China, it has only taken 2 years. We will continue to make every effort to advance other research and development of pralsetinib in China, more broadly assessing the efficacy of this agent in patients with treatment-naïve RET fusion-positive NSCLC, as well as patients with thyroid cancer and other solid tumors driven by RET alterations, so as to meet the urgent medical needs of these groups of Chinese cancer patients at the earliest possible date.”

CStone Pharmaceuticals has an exclusive collaboration and license agreement with Blueprint Medicines for the development and commercialization of pralsetinib in Greater China, which encompasses Mainland China, Hong Kong, Macau and Taiwan. Blueprint Medicines and Roche are co-developing pralsetinib globally, excluding Greater China. Blueprint Medicines and Genentech, a member of the Roche Group, will co-commercialize pralsetinib in the U.S. and Roche has exclusive commercialization rights for pralsetinib outside of the U.S., excluding Greater China.

- End -

About the ARROW study

The ARROW study is a global clinical study designed to assess the safety, tolerability, and efficacy of pralsetinib in patients with RET fusion-positive NSCLC, RET-mutant medullary thyroid cancer, or other advanced solid tumors with RET alterations. According to previous announcements released by CStone, Chinese sites completed dosing of the first RET fusion-positive NSCLC patient previously treated with platinum-based chemotherapy in August 2019 and completed the last patient enrollment in December of the same year. CStone plans to present additional data for pralsetinib from patients in the Chinese cohort at an upcoming academic conference.

About Pralsetinib

Pralsetinib is an investigational, once-daily oral precision therapy specifically designed for highly potent and selective targeting of oncogenic RET alterations. Blueprint Medicines is developing pralsetinib for the treatment of patients with RET-altered NSCLC, thyroid cancer and other solid tumors. The U.S. Food and Drug Administration (U.S. FDA) has granted Breakthrough Therapy Designation to pralsetinib for the treatment of RET fusion-positive NSCLC that has progressed following platinum-based chemotherapy, and RET mutation-positive MTC that requires systemic treatment and for which there are no acceptable alternative treatments. In May 2020, Blueprint Medicines announced that the U.S. and EU marketing applications for pralsetinib for the treatment of locally advanced or metastatic RET fusion-positive NSCLC were accepted by the U.S. FDA and validated by the European Medicines Agency, respectively.

Pralsetinib was designed by Blueprint Medicines’ research team, leveraging the company’s proprietary compound library. In preclinical studies, pralsetinib consistently demonstrated sub-nanomolar potency against the most common RET fusions, activating mutations and predicted resistance mutations. In addition, pralsetinib demonstrated markedly improved selectivity for RET compared to pharmacologically relevant kinases, including approximately 80-fold improved potency for RET versus VEGFR2. By suppressing primary and secondary mutants, pralsetinib has the potential to overcome and prevent the emergence of clinical resistance. This approach will enable durable clinical responses across a diverse range of RET alterations, with a favorable safety profile.

About CStone

CStone Pharmaceuticals (HKEX: 2616) is a biopharmaceutical company focused on developing and commercializing innovative immuno-oncology and precision medicines to address the unmet medical needs of cancer patients in China and worldwide. Established in 2015, CStone has assembled a world-class management team with extensive experience in innovative drug development, clinical research, and commercialization. The company has built an oncology-focused pipeline of 15 drug candidates with a strategic emphasis on immuno-oncology combination therapies. Currently, 5 late-stage candidates are at pivotal trials. With an experienced team, a rich pipeline, a robust clinical development-driven business model and substantial funding, CStone’s vision is to become globally recognized as a leading Chinese biopharmaceutical company by bringing innovative oncology therapies to cancer patients worldwide.

Forward-looking Statement

The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article, statements of, or references to, our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development.