NEW YORK – Chinese precision oncology platform company Genetron Holdings and its strategic partner CStone Pharmaceuticals said on Friday that they have launched a multi-center clinical trial in China for the joint development of a companion diagnostic test for avapritinib (Blueprint Medicines's Ayvakit).
Avapritinib is a kinase inhibitor approved by the US Food and Drug Administration for the treatment of adults with unresectable or metastatic gastrointestinal stromal tumors (GIST) harboring an exon 18 mutation in the PDGFRA gene, including PDGFRA D842V mutations. Genetron Health and CStone are developing a CDx kit to detect the D842V mutation using a real-time PCR fluorescent probe, combined with specific primers, Taqman probes, and highly specific Taq enzymes, to detect the mutation with high specificity and sensitivity in DNA samples. The test has been validated by the testing center of the National Medical Products Administration (NMPA) and is now being used in this multi-center clinical trial in China, the partners said.
CStone submitted New Drug Applications for avapritinib in PDGFRA exon 18 mutant-GIST to regulatory agencies in Taiwan and Mainland China in March and April, respectively. The Chinese regulatory application has been accepted by the Center for Drug Evaluation of the NMPA for priority review.
Blueprint is also developing avapritinib for patients with advanced and indolent systemic mastocytosis (SM). The FDA granted breakthrough therapy designation to avapritinib for the treatment of advanced SM, including subtypes of aggressive SM such as SM with an associated hematologic neoplasm and mast cell leukemia.
In June, CStone partnered with Chinese molecular diagnostics firm Burning Rock Biotech to co-develop and commercialize companion diagnostics in China for Blueprint's pralsetinib, an investigational treatment for the detection of RET alterations in cancer patients.