SUZHOU, China, June 5^th, 2023 – The partner of CStone Pharmaceuticals (“CStone”, HKEX: 2616), Blueprint Medicines announced on May 22^nd that the U.S. Food and Drug Administration (FDA) has approved AYVAKIT^® (avapritinib) for the treatment of adults with indolent systemic mastocytosis (ISM). ISM is a rare hematologic disorder that can lead to a range of debilitating symptoms across multiple organ systems and a significant impact on patients’ quality of life.

Discovered by CStone’s partner Blueprint Medicines, AYVAKIT is a potent, selective and orally available inhibitor of KIT and PDGFRA mutant kinases. CStone has an exclusive collaboration and license agreement with Blueprint Medicines for the development and commercialization of AYVAKIT in Mainland China, Hong Kong, Macau and Taiwan.

Dr. Jason Yang, CEO of CStone said, “We are delighted to see the FDA approval of AYVAKIT for the treatment of ISM, which represents a significant step forward in improving the lives of patients living with the disease. AYVAKIT has been approved in China for the treatment of adult patients with unresectable or metastatic gastrointestinal stromal tumor (GIST) harboring the PDGFRA exon 18 mutation, including PDGFRA D842V mutations. We hope to bring this innovative treatment to a broader population of patients in China in the future.”

Detailed results from the PIONEER trial, including open-label extension study data showing the clinical benefits of AYVAKIT through 48 weeks of treatment, were presented in February 2023 at the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting. In addition, the detailed results from the PIONEER trial of AYVAKIT in patients with ISM were published on May 23, 2023 in NEJM Evidence, a journal affiliated with The New England Journal of Medicine Group.

For more details on the FDA approval of AYVAKIT in ISM, please go to https://ir.blueprintmedicines.com/news-releases/news-release-details/fda-approves-ayvakitr-avapritinib-first-and-only-treatment.

About CStone

CStone (HKEX: 2616) is a biopharmaceutical company focused on research, development, and commercialization of 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 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, CStone has received ten NDA approvals for its four drugs. Multiple late-stage drug candidates are now under pivotal clinical trials or registration. CStone’s vision is to bring innovative oncology therapies to cancer patients worldwide.

For more information about CStone, please visit www.cstonepharma.com

Forward-looking statements

The forward-looking statements made in this article only relate to events or information as of the date when the statements are made in this article. Except as required by law, we undertake no obligation to update or publicly revise 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. All statements in this article are made on the date of publication of this article and may change due to future developments.

Trademarks

Blueprint Medicines, AYVAKIT and associated logos are trademarks of Blueprint Medicines Corporation.

Disclaimer: only for communication and scientific use by medical and health professionals.