Avapritinib, an oral, selective KIT and PDGFRA inhibitor, readily fits into the ATP binding pocket, with the activation loop in an open, aspartate (D)-phenylalanine (F)-glycine (G) motif (DFG)-in conformation23,31,60 In a phase I study, avapritinib was found to be active in patients with PDGFRA D842V mutant GIST with an ORR of 88%.32,62 This study led to FDA and European Medicines Agency approvals in 2020 use in GIST with PDGFRA exon 18 and with PDGFRA D842V mutations, respectively.57,58. This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.