Clinical activity of avapritinib in ≥ fourth-line (4L+) and PDGFRA Exon 18 gastrointestinal stromal tumors (GIST).

11022Background: Targeting oncogenic KIT and PDGFRA mutations revolutionized treatment of patients (pts) with advanced GIST; however, nearly all pts succumb to resistant disease. Avapritinib is a p...