Regorafenib (BAY 73-4506, commercial name Stivarga) is an oral multi-kinase inhibitor developed by Bayer which targets angiogenic, stromal and oncogenic receptor tyrosine kinase (RTK). Regorafenib shows anti-angiogenic activity due to its dual targeted VEGFR2-TIE2 tyrosine kinase inhibition. It is currently being studied as a potential treatment option in multiple tumor types.
Approvals and indications 
Metastatic colorectal cancer 
Regorafenib demonstrated to increase the overall survival of patients with metastatic colorectal cancer and has been approved by the US FDA on September 27, 2012.
Advanced gastrointestinal stromal tumors 
On February 25, 2013 the US FDA expanded the approved use to treat patients with advanced gastrointestinal stromal tumors that cannot be surgically removed and no longer respond to other FDA-approved treatments for this disease. In a clinical study with 199 patients regorafenib treated patients had a delay in tumor growth (progression-free survival) that was, on average, 3.9 months longer than patients who were given placebo.
Adverse effects 
Stivarga is being approved with a Boxed Warning alerting patients and health care professionals that severe and fatal liver toxicity occurred in patients treated with Stivarga during clinical studies. Serious side effects, which occurred in less than one percent of patients, were liver damage, severe bleeding, blistering and peeling of skin, very high blood pressures requiring emergency treatment, heart attacks and perforations (holes) in the intestines. The most common side effects reported in patients treated with Stivarga include weakness or fatigue, loss of appetite, hand-foot syndrome (also called palmar-plantar erythrodysesthesia), diarrhea, mouth sores (mucositis), weight loss, infection, high blood pressure, and changes in voice volume or quality (dysphonia).