Efficacy and safety of regorafenib in Korean patients with advanced gastrointestinal stromal tumor after failure of imatinib and sunitinib: A multicenter study based on the management access program.

Abstract

175 Background: GRID phase III trial showed that regorafenib improves progression free survival (PFS) in patients (pts) with advanced gastrointestinal stromal tumors (GIST) after failure of imatinib and sunitinib. This study aims to confirm the efficacy and safety of regorafenib for advanced GIST in Korean pts. Methods: Clinical records were reviewed from 57 Korean pts with advanced GIST who failed both imatinib and sunitinib and were treated with regorafenib under MAP between December 2012 and November 2013. Pts received regorafenib 160mg p.o. once daily in a 3 weeks on/1 week off schedule, every 4 weeks until intolerable toxicities or disease progression with no benefit by physician’s discretion. Results: Out of total 57 pts, none achieved a complete or a partial response whereas 25 pts (44%) showed stable disease for ≥ 12 weeks. With a median follow-up of 8.6 months (range, 0.2-15.3), median PFS and overall survival (OS) were 4.5 months (95% CI, 3.8-5.3) and 12.2 months (95% CI, 10.1-14.3), respectively. Interestingly, 15 patients (26%) experienced an exacerbation of cancer-related symptoms (abdominal pain in 8 and abdominal distension in 5) during the rest period of regorafenib, which were reduced with resumption of regorafenib. The most common grade 3 or 4 adverse events were hand-foot skin reaction (25%), hypertension (7%), and skin rash (7%). The dose of regorafenib was reduced in 44 patients (77%) because of toxicities, mainly due to hand-foot skin reaction (n=31). There was no treatment-related death. Conclusions: We could confirm the efficacy and safety ofregorafenib for advanced GIST after failure of imatinib and sunitinib reported in GRID trial in Korean pts. Considering exacerbation of cancer-related symptoms during rest periods, continuous dosing schedule of regorafenib needs to be explored in future clinical trials.