Mutant Gastrointestinal Stromal Tumors Yana Samun Sabbin Yarda da Magunguna

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 and certain other drug candidates in Mainland China, Hong Kong, Macau and Taiwan. Blueprint Medicines retains development and commercial rights for AYVAKIT in the rest of the world.

Dr. Frank Jiang, Chairman and CEO of CStone, said, “AYVAKIT is CStone’s first product approval in Hong Kong, China. Earlier this year, AYVAKIT was also approved in Mainland China and Taiwan. We are very glad to provide this innovative treatment to more GIST patients whose tumors harbor the PDGFRA D842V mutation. CStone is committed to bringing forward effective, innovative therapies to patients around the world. In the future, we will strive to accelerate the development of novel therapies to fulfill the unmet medical needs of more cancer patients.”

The Hong Kong Department of Health (DOH) has approved AYVAKIT based on data from the NAVIGATOR study, an open-label, dose-escalation/dose-expansion phase I study designed to evaluate the safety and efficacy of AYVAKIT in patients with unresectable or metastatic GIST. In December 2020, the European Journal of Cancer (EJC) published updated data from the NAVIGATOR study enrolling PDGFRA D842V mutant GIST patients. In 38 patients with PDGFRA D842V mutant GIST who received a starting dose of 300 mg or 400 mg once daily, the overall response rate (ORR) was 95% (36/38 patients). In 28 of these patients who had a starting dose of 300 mg once daily, the ORR was 96% (27/28 patients). The disease control rate (DCR) of all dose groups was 100%. The median duration of response (DOR) of all dose groups was 27.6 months. The most common treatment-emergent adverse events were anemia, increased blood bilirubin, decreased white blood cell count, increased blood creatine phosphokinase, increased aspartate aminotransferase, face edema, eyelid edema, decreased neutrophil count and hair color changes. The data showed that AYVAKIT demonstrated robust, durable, and deep clinical activity, with a generally well-tolerated safety profile.