The FDA has recently approved Ayvakit (avapritinib) for the treatment of unresectable and metastatic gastrointestinal stromal tumor (GIST) that occurs most commonly in the stomach or small intestine. The treatment is specifically for GIST that harbors a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 mutation. For Ayvakit, it works as a kinase inhibitor that blocks a type of enzyme called a kinase and keeps the cancer cells from thriving.
“GIST harboring a PDGFRA exon 18 mutation do not respond to standard therapies for GIST. However, today’s approval provides patients with the first drug specifically approved for GIST harboring this mutation,” said Richard Pazdur, M.D., director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research. “Clinical trials showed a high response rate with almost 85% of patients experiencing tumor shrinkage with this targeted drug.”
GISTs originate from from specialized nerve cells found in the lining of gastrointestinal tract. A mutation in any of these nerve cells likely lead to the development of GIST and more than half of GISTs start in the stomach and the small intestine.
Ayvakit was approved based on results of a clinical trial of 300 mg or 400 mg dose given to patients with GIST harboring a PDGFRA exon 18 mutation. The study examined the efficacy of Ayvakit’s ability to shrink tumors. Some of the noted side effects include swelling, fatigue, and loss of focus, abdominal pain, constipation, and rash. Some dangerous complications include the possibility of intracranial hemorrhage and mood disorders.
Clinicians should counsel pregnant women of the harms of Ayvakit to a developing fetus or newborn baby, and females of reproductive age.
Source: U.S Food and Drug Administration