Efficacy and safety of sunitinib in Chinese patients with imatinib-resistant or -intolerant gastrointestinal stromal tumors.

AIMS

To assess the efficacy and safety of sunitinib in Chinese patients with imatinib-resistant or -intolerant gastrointestinal stromal tumors (GISTs), and evaluate the impact of genotype on sunitinib efficacy.

MATERIALS & METHODS: In a single-arm retrospective study, 55 patients with recurrent or metastatic GISTs who were resistant or intolerant to prior imatinib treatment received sunitinib for at least one treatment cycle.

RESULTS

The median progression-free survival was 35 weeks (95% CI: 24.6-45.4) in patients who received sunitinib 37.5 mg/day as a continuous daily dose versus 30 weeks (95% CI: 12.8-47.2) in those who received sunitinib 50 mg/day as a 4-weeks-on, 2-weeks-off (4/2) schedule (p = 0.707). The median overall survival of all patients was 86 weeks (95% CI: 75.0-97.0). Patients with KIT exon 9 mutations had a significantly longer progression-free survival compared with those with KIT exon 11 mutations and patients with wild-type GISTs (p = 0.022). Sunitinib therapy was well tolerated, with most adverse events rated as grade 1 or 2 in severity. The sunitinib 37.5 mg/day continuous daily dose schedule was better tolerated by Chinese GIST patients than the 50 mg/day 4/2 schedule.

CONCLUSION

Sunitinib was effective and well tolerated in Chinese patients with imatinib-resistant or -intolerant GISTs. Patients with KIT exon 9 mutations showed the best efficacy. A 37.5 mg/day continuous daily dose sunitinib dosing schedule appears to be the optimal choice for Chinese patients due to a decreased incidence of adverse events.