The U.S. Food and Drug Administration expanded the approved use of Stivarga (regorafenib) to treat patients with advanced gastrointestinal stromal tumors (GIST). The multi-kinase inhibitor is intended to treat patients whose tumors cannot be surgically removed or are metastatic, and are no longer responding to the other FDA-approved treatments for GIST: imatinib or sunitinib.
“Stivarga is the third drug approved by the FDA to treat gastrointestinal stromal tumors,” Richard Pazdur, MD, Director of the FDA's Office of Hematology and Oncology Products, said in a news release. “It provides an important new treatment option for patients with GIST in which other approved drugs are no longer effective.”
Stivarga was reviewed under the FDA's priority review program, which provides an expedited six-month review for drugs that may provide safe and effective therapy when no satisfactory alternative therapy exists, or offer significant improvement compared with marketed products. The drug has also been granted orphan product designation because it is intended to treat a rare disease. An estimated 3,300 to 6,000 new cases of GIST occur each year in the U.S., according to the National Cancer Institute.
Stivarga's safety and effectiveness were evaluated in a clinical study of 199 patients with GIST whose tumors could not be surgically removed and that progressed after treatment with Gleevec or Sutent. Patients were randomly assigned to take Stivarga or a placebo until the cancer progressed or the side effects became unacceptable. All patients also received best supportive care.
Progression-free survival was significantly longer for patients taking Stivarga compared with patients taking the placebo: 4.8 versus 0.9 months. Patients who received the placebo were given the opportunity to switch to Stivarga when their cancer progressed.
The most common side effects were weakness and fatigue, palmar-plantar erythrodysesthesia, diarrhea, loss of appetite, high blood pressure, mouth sores, infection, change in voice volume or quality, pain, weight loss, stomach pain, rash, fever, and nausea. Serious side effects, which occurred in less than one percent of the patients, were liver damage, severe bleeding, blistering or peeling of the skin, very high blood pressures, heart attacks, and proliferations in the intestines. The drug includes a Boxed Warning citing the risk of hepatoxicity.
Stivarga, which was approved in September 2012 to treat colorectal cancer, is marketed by Bayer HealthCare Pharmaceuticals.