China-based CStone Pharmaceuticals (HKG: 2616) announced that its US partner, Blueprint Medicines, published detailed data from the PIONEER regulatory study for Ayvakit (avapritinib) at the American Academy of Allergy, Asthma, and Immunology (AAAAI) annual meeting this year. Ayvakit is a tyrosine kinase inhibitor used to treat gastrointestinal stromal tumors (GIST) and indolent systemic mastocytosis (ISM).
Study Findings
The data showed that Ayvakit achieved statistically and clinically significant improvements in the total symptom score, with enhancements deepening over time. All types of symptoms improved, and the quality of life questionnaire for mastocytosis also demonstrated significant improvements. Compared to a placebo, the drug exhibited good safety and supports the clinical needs for long-term treatment of ISM.
Regulatory Filings and Study Design
Blueprint Medicines has filed a supplementary New Drug Application (sNDA) for Ayvakit with the US FDA, which was awarded priority review status with a PDUFA date of May 22, 2023. Additionally, the company has filed a Marketing Authorization Application (MAA) in the European Union for use in ISM. The randomized, double-blind, placebo-controlled regulatory study includes dosage discovery, regulatory study, and open-label expansion study, with key endpoints focusing on patient-reported changes in disease symptoms, quality of life, measurement of mast cell load, and safety.
Background of Ayvakit
Ayvakit is a KIT and PDGFRA-targeted tyrosine kinase inhibitor in-licensed from Blueprint Medicines in June 2018. The drug has been approved to treat unresectable or metastatic GIST with PDGFRA exon 18 mutation (including PDGFRA D842V mutation) and advanced systemic mastocytosis (SM) in the Chinese mainland, Taiwan, and Hong Kong, as well as advanced SM with blood tumor (SM-AHN) and mast cell leukemia (MCL) after at least one systemic treatment, and gastrointestinal stromal tumor with PDGFRA D842V mutation that cannot be resected or metastasized in Europe.
Significance of the Findings
The detailed data presented at the AAAAI meeting further validate the efficacy and safety of Ayvakit in treating ISM, supporting its potential as a long-term treatment option for patients with this condition. This development highlights CStone Pharmaceuticals’ commitment to advancing innovative therapies for rare diseases.-Fineline Info & Tech
