Dr. Trent on the Role of Avapritinib in PDGFRA Exon 18+ GIST

Jonathan C. Trent, MD, PhD, professor and associate director for Clinical Research at the Sylvester Comprehensive Cancer Center, University of Miami Health System, discusses the role of avapritinib (Ayvakit) in PDGFRA exon 18–positive gastrointestinal stromal tumor (GIST).

In January 2020, the FDA approved avapritinib for the treatment of adult patients with unresectable or metastatic GIST who harbor a PDGFRA exon 18 mutation, including PDGFRA D842V mutations.

Prior to the approval, findings from the randomized phase 3 VOYAGER trial failed to demonstrate a survival benefit with avapritinib vs regorafenib (Stivarga) in patients with locally advanced, unresectable or metastatic GIST. However, data from the phase 1 NAVIGATOR study showed an 84% overall response rate with avapritinib in patients with PDGFRA exon 18–mutant GIST.

PDGFRA exon 18–mutant GIST is resistant to all other available TKIs for patients with GIST, so the approval of avapritinib filled a significant unmet need for this specific patient population, says Trent. Moreover, the efficacy demonstrated with avapritinib was similar to that demonstrated with imatinib (Gleevec) in patients with KIT-mutant GIST, concludes Trent.