P1-12-2 - A Retrospective Analysis of the Efficacy and Safety of Regorafenib in Patients with Chemo-Refractory Colorectal Cancer

Abstract

Regoragenib is a novel oral multi-kinase inhibitor, which was approved by Japanese Ministry of Health, Labor and Welfare in March 2013. The purpose of this study was to verify the efficacy and safety of regorafenib in Japanese patients with colorectal cancer. We retrospectively analyzed 14 patients with chemo-refractory colorectal cancer, who had taken regorafenib orally in Tohoku University Hospital between June 1, 2013 and January 30, 2014. Mean age of the patients was 62.4 years old and 8 patients were male. Twelve patients had colon cancer and 2 patients had rectal cancer. Ten patients had liver metastasis, 3 had abdominal dissemination. Nine patients (64%) had KRAS mutation. Median time to failure was 48 days and the mean number of therapeutic course was 2.8. Among the patients who had measurable lesions, the best overall response was stable disease in 3 patients, and progressive disease in 3. Because of adverse events, the therapy was discontinued in 4 patients before the first response evaluation. Four patients had not yet had the first evaluation for the response until January 1, 2014. Major adverse events (≥ grade 2) were observed in 11 patients (79%), including elevation of liver enzyme (n = 8), hand-foot skin reaction (n = 7), and anorexia (n = 5). Severe adverse events (≥ grade 3) were seen in 8 patients (57%), including elevation of liver enzyme (n = 5), hand-foot skin reaction (n = 1), fatigue (n = 1), hypertension (n = 1), anorexia (n = 1), aspiration (n = 1) and rhabdomyolysis (n = 1). These treatment effects and toxic profiles by regorafenib treatment were consistent with those reported in previous other studies. In conclusion, our data support the notion that regorafenib is one of well-tolerated treatment option for chemo-refractory, progressive or recurrent colorectal cancer in Japanse populations as well. We also report a case of rhabdomyolysis which had never been reported as an adverse event of regorafenib therapy before its approval.