The two patients in the RA cohort still obtained PR from avapritinib despite receiving prior treatment with ripretinib, supporting the anti-tumor activity of avapritinib in GIST with PDGFR exon 18 mutations even in later lines after ripretinib (Figure 4d), as is well established from prior data [29]. Here, PDGFRB is linked to gastrointestinal stromal tumor.