First FDA-approved Treatment for Desmoid Tumors

The FDA has approved nirogacestat for the treatment of noncancerous but painful growths called desmoid tumors. 

The U.S. Food and Drug Administration (FDA) has approved nirogacestat (Ogsiveo) for adult patients with desmoid tumors that are progressing and require systemic treatment. 

Some desmoid tumors express high levels of a protein called Notch that is thought to drive their growth. Nirogacestat inhibits the enzyme gamma secretase, which activates Notch, thereby suppressing Notch signaling. Nirogacestat is the first FDA-approved treatment for desmoid tumors. 

The approval was based on data from the international, multicenter, randomized, double-blind, placebo-controlled, phase III DeFi clinical trial that recruited 142 patients with desmoid tumors who were not eligible for surgery and whose tumors had progressed within 12 months after screening. Patients were randomly assigned (1:1) to receive nirogacestat or placebo until disease progression or unacceptable toxicity. 

Median progression-free survival was not reached in the nirogacestat arm and was 15.1 months in the placebo arm. Patients treated with nirogacestat had an overall response rate of 41% compared to 8% among patients treated with placebo. 

Desmoid tumors are noncancerous growths that arise from the connective tissue that supports bones, ligaments, muscles, and organs. While they don’t metastasize to other parts of the body, they can sometimes grow quickly and invade local tissue, which can be painful and potentially interfere with organ function. According to the National Cancer Institute, each year, desmoid tumors occur in every two to four people per million worldwide. 

The FDA rendered its decision on November 27, 2023.