Clinical benefit of sunitinib in gastrointestinal stromal tumors with different exon 11 mutation genotypes.

Abstract

To assess the efficacy of second-line sunitinib therapy in gastrointestinal stromal tumor patients with different exon 11 mutation genotypes. Thirty eight of the 75 patients received imatinib (IM) dose escalation followed by sunitinib (IM escalation group), while 37 were switched to sunitinib directly after the failure of first-line IM treatment (sunitinib group). Progression-free survival and overall survival were compared. The median progression-free survival in the sunitinib group was significantly longer than in the IM escalation group (14 vs 4 months; p < 0.001), so was in patients with exon 11 deletions (16 vs 3 months; p < 0.001). Patients who have an exon 11 deletion mutation are more likely to benefit from switching to sunitinib directly than from IM dose escalation.