Evolving role of regorafenib for the treatment of advanced cancers

Regorafenib is an oral tyrosine kinase inhibitor (TKI) approved for the treatment of refractory metastatic colorectal cancer (mCRC), advanced gastrointestinal stromal tumors (GIST) previously treated with imatinib and sunitinib, and unresectable hepatocellular carcinoma (HCC) following progression on sorafenib. Regorafenib was initially approved for mCRC based on improved overall survival (OS) in the randomized, placebo-controlled, phase 3 CORRECT trial, which was confirmed in an expanded population of Asian patients in the randomized, placebo-controlled phase 3 CONCUR trial. Approvals in GIST, and more recently in HCC, were based on the results from the randomized, placebo-controlled, phase 3 GRID and RESORCE trials, respectively. In this review, we provide a comprehensive summary of the clinical evidence for approval of regorafenib in mCRC, GIST, and HCC, present emerging evidence of regorafenib activity in other tumor types (namely, gastroesophageal cancer, sarcomas, biliary tract cancer, and glioblastoma), and discuss trials in progress within the context of regorafenib's mechanism of action. We describe recent advances and key lessons learned with regorafenib, including the importance of managing common drug-related toxicities using dose-optimization strategies, the search for biomarkers to predict response to treatment, and highlight some of the unaddressed questions and future directions for regorafenib across tumors.