Regorafenib in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the GI tract and constitute less than 1% of all digestive tract tumors--the stomach is the most common site. Regorafenib is a multi-tyrosine kinase inhibitor with regulatory approvals granted for colorectal cancers and GIST. The US FDA granted approval for the use of regorafenib in February 2013 in patients with advanced GIST for those who had failed on imatinib and sunitinib. This was based on a pivotal Phase III double-blind placebo controlled randomized trial that showed that there was a significant improvement in progression-free survival for patients on regorafenib.