The U.S. Food and Drug Administration (FDA) has approved the kinase inhibitor, Qinlock (ripretinib) tablets, as a fourth-line treatment for advanced gastrointestinal stromal tumor (GIST), a type of tumor that originates in the gastrointestinal tract.
GIST is a rare cancer that afflicts 4,000 – 6,000 people in the United States. GISTs develop when abnormal cells form in the gastrointestinal tract (usually in the stomach, small intestine, or large intestine).
The approval was largely based on the results of a randomized, double-blind, placebo-controlled clinical trial that enrolled 129 patients with advanced GIST who had received prior treatment with other FDA-approved targeted therapies (imatinib, sunitinib and regorafenib). The trial compared progressive-free survival (PFS) in patients given ripretinib vs those given placebo. The trial found that those given ripretinib had an average PFS of 6.3 months compared to 1.0 month for those given placebo.
In a news release, Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence said, “Despite the progress that has been made over the past 20 years in developing treatments for GIST, including four FDA-approved targeted therapies – imatinib in 2002, sunitinib in 2006, regorafenib in 2013 and avapritinib earlier this year – some patients don’t respond to treatment and their tumors continues to progress. Today’s approval provides a new treatment option for patients who have exhausted all FDA-approved therapies for GIST.”
The most common side effects with riperetinib includes alopecia, fatigue, nausea, abdominal pain, constipation, myalgia, diarrhea, decreased appetite, palmar-plantar erythrodysesthesia syndrome, and vomiting.
The drug may also can cause serious side effects including skin cancer, hypertension and cardiac dysfunction manifested as ejection fraction decrease. Health care providers should routinely check for symptoms and signs of these and other risks.