Avapritinib for PDGFRA exon 18 mutant GISTMarch 6, 2020
The US FDA has approved avapritinib for the treatment of adults with unresectable or metastatic gastrointestinal stromal tumour (GIST) harbouring a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 mutation, including PDGFRA D842V mutations.
Avapritinib is the first precision therapy approved to treat a genomically defined population of patients with GIST.
The approval was based on efficacy results from the phase 1 NAVIGATOR clinical trial, as well as combined safety results from multiple clinical trials for avapritinib. In patients with PDGFRA exon 18 mutant GIST, the drug showed an overall response rate (ORR) of 84 percent (95% CI: 69%, 93%), and a median duration of response (DOR) was not reached.
Avapritinib is a kinase inhibitor and is the only FDA-approved type 1 inhibitor for GIST that works by directly binding to the active kinase conformation from which mutant KIT and PDGFRA signal, Blueprint Medicines Corporation said.