After the approval of Zaltrap (ziv-aflibercept) for colorectal cancer in August, there's more good news for metastatic colorectal cancer patients. This morning, the Food and Drug Administration announced that it had approved Stivarga (regorafenib) for patients with metastatic colorectal cancer (mCRC) who have progressed after trying other therapies. The FDA had granted the drug a priority review in late June, which guarantees a drug will be reviewed within six months.Stivarga works as a multi-kinase inhibitor, which means it targets several different pathways that can promote tumor growth, including the vascular endothelial growth factor receptor (VEGF), which signals tumor blood vessel growth, and c-KIT, an oncogene that also helps cancer growth. Patients take the drug orally, once-a-day in four week cycles (three weeks on, one week off before starting the therapy again).The approval is based on the phase 3 CORRECT trial, which randomly assigned 760 mCRC patients who had prior treatment to either receive Stivarga or placebo. All patients in the trial received best supportive care. Stivarga was shown to extend median overall survival to 6.4 months compared with the 5 months for those in the placebo arm. The drug also delayed tumor growth by two months compared with the 1.7 months for those on placebo.Common side effects include fatigue, hand-foot syndrome and diarrhea. The drug also carries a warning that severe and fatal liver toxicity can sometimes occur.Stivarga has already been made available to some patients through an extended access program. Regorafenib is also being considered for FDA approval for patients with gastrointestinal stromal tumors (GIST). Be sure to check out CURE's feature on colorectal cancer in our Winter issue.