Bayer Reports Positive Outcomes for Sarcoma Patients with Regorafenib
Bayer AG has announces that the results of two separate trials show positive outcomes in patients with two forms of cancer, metastatic bowel cancer and a rare form of tumor known as gastrointestinal stromal tumors (GISTs), a type of soft-tissue sarcoma.
Regorafenib (trade name Stivarga) was approved by the Food and Drug Administration (FDA) on September 27, 2012 for the treatment of patients with metastatic colorectal cancer who have previously been treated with other chemotherapy drugs without success. The drug is an oral mulit-kinase inhibitor that interrupts mechanisms involved in tumor growth and progression. In a study known as CORRECT (Colorectal cancer treated with regorafenib or placebo after failure of standard therapy), Stivarga was shown to increase overall survival and progression-free survival compared to placebo.
The latest study on Regorafenib, published in The Lancet, indicates that patients with GISTs treated with the drug also demonstrated increased survival rates. Gastrointestinal stromal tumors are relatively rare and more than 40% of cases recur and begin to spread. There are currently only two drugs - ‘molecular targeted’ therapies called imatinib and sunitinib – approved to treat GISTs.
In a trial conducted at the Dana-Farber Cancer Insitute and Harvard Medical School in Boston, GIST patients treated with 160 mg regorafenib had an average progression free survival time of 4.8 months, compared with 0.9 months to those in the matched placebo group
Unfortunately, side effects were common, with the most frequently observed adverse responses being fatigue, decreased appetite, hand-foot skin reaction, diarrhea, mucosititis (inflammation of the mucous membranes lining the digestive tract, weight loss, infection, voice changes/hoarseness, and hypertension. More serious but less common side effects include hemorrhage and gastrointestinal perforation.
There is also a black box warning on Regorafenib describing the risk of severe and sometimes fatal hepatotoxicity (liver toxicity) which occurred in 0.3% of Stivarga-treated patients across all clinical trials.
The FDA has granted Bayer priority review status for Regorafenib for use in patients with gastrointestinal stromal tumor. Bayer has noted that it is one of its five key drugs fueling an annual sales potential of $7.03 billion.