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

Aim: To assess the efficacy of second-line sunitinib therapy in gastrointestinal stromal tumor patients with different exon 11 mutation genotypes.

Patients & Methods: 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.

Results: 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).

Conclusion: Patients who have an exon 11 deletion mutation are more likely to benefit from switching to sunitinib directly than from IM dose escalation.