An update on the safety and efficacy of regorafenib in the treatment of solid cancers.

INTRODUCTION: Regorafenib is a multi-targeted kinase inhibitor that has been approved recently for the treatment of certain gastrointestinal (GI) cancers. This review examines the scientific evidence on the efficacy and safety of this agent in Phase I to III studies. AREAS COVERED: A literature review was performed based on published studies from PubMed and abstracts from international conferences. EXPERT OPINION: Regorafenib has expanded the treatment options of patients with treatment-refractory gastrointestinal stromal tumor (GIST) and metastatic colorectal cancer (CRC). Ongoing studies are now investigating the activity of regorafenib as earlier line of therapy in CRC as monotherapy or in combination with chemotherapy. In the next 5 years, the activity of regorafenib will be further defined in other cancers such as renal cell cancer (RCC), hepato-biliary and upper GI cancers. In terms of safety, clinical trials suggest that the incidence and severity of toxicities may be higher in certain populations such as those with RCC or GIST. However, most of the common toxicities of regorafenib could be managed with dose modification without resorting to permanent drug discontinuation. Education of both patients and clinicians is thus important in minimizing treatment-related toxicities and improving drug compliance.