Avapritinib (BLU-285) is a highly potent, selective, and orally active KIT and PDGFRA activation loop mutant kinases inhibitor with IC50s of 0.27 and 0.24 nM for KIT D816V and PDGFRA D842V, respectively. Avapritinib (BLU-285) binds the active conformation of the kinase and shows antitumor activity. Avapritinib (BLU-285) attenuates the transport function of both ABCB1 and ABCG2.