Efficacy of Avapritinib in the Fourth- or Later-line GIST Population in Cohort 2
The efficacy population in cohort 2 consisted of 23 patients who received at least 3 previous lines of TKI therapy (ie, in the fourth- or later-line setting) and were without PDGFRA D842V mutation. These patients received a starting dose of 300 mg. At the data cutoff date, the median follow-up was 11.8 months in the fourth- or later-line treatment group.Per IRRC assessment, PR was achieved in 5 patients (ORR 22%; 95% CI: 8%–44%) (Kaplan-Meier plots of the DOR and PFS indicated that the IRRC-assessed median DOR in the fourth- or later-line treatment population was not reached and the median PFS was 5.6 months (95% CI: 3.5-11.0) (Kaplan-Meier plots of investigator assessments. (Twelve patients achieved PR with an ORR assessed by Choi criteria of 52% (95% CI: 31%–73%), and the CBR per Choi criteria was 57% (95% CI: 35%–77%) (