Bayer got FDA approval last Thursday to market a colon cancer treatment drug called Regorafenib (Stivarga). This drug inhibits multiple kinase enzymes and has been approved for use in colorectal cancer in cases that have not responded well to other therapies. Approval came after a study which showed the survival rate for such patient increased from an average of 5 months to 6.4 months. While that does not seem like much, it is hoped that the approval will mean that this drug can be combined with other new treatments for a significant benefit.
Of course, patients in this study were receiving optimal medical care. Even so, troubling adverse events were reported, including skin reactions, diarrhea, anorexia, and hypertension. Each of these adverse event was suffered by more than 25% of the participants. Moreover, a boxed warning will state that "severe and fatal liver toxicity occurred in patients treated with Stivarga during clinical studies," according to the FDA's announcement.
The drug, developed by Bayer, targets multiple kinase enzymes, including several related to the vascular endothelial growth factor receptor and others associated with KIT, RET, and the platelet-derived growth factor and fibroblast growth factor receptors.
"Stivarga is the latest colorectal cancer treatment to demonstrate an ability to extend patients' lives and is the second drug approved for patients with colorectal cancer in the past 2 months," said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in FDA's Center for Drug Evaluation and Research, in a statement.
Regorafenib has also shown promise for treating gastrointestinal stromal tumors. The company applied in August for FDA approval. Bayer's new drug was reviewed under the FDA's fast-track system for quick processing because patients with metastatic colorectal cancer represent a major unmet medical need.