An expert discussion highlighted how treatment of desmoid tumors has changed in recent years. Because many of these rare soft-tissue tumors can remain stable or even shrink on their own, doctors now often recommend active monitoring rather than immediate surgery, which has a high risk of recurrence. However, patients with growing or symptomatic tumors usually require systemic treatment.
The gamma-secretase inhibitor Ogsiveo (nirogacestat) has emerged as a leading treatment option for progressive desmoid tumors. In the Phase 3 DeFi trial, the drug reduced the risk of disease progression by 71% compared with placebo. It also achieved a 91% disease control rate and an objective response rate of more than 40%, with responses becoming stronger over time. Long-term follow-up showed that tumor control was durable, with most progression events occurring within the first year of treatment.
The drug’s safety profile was generally manageable, but ovarian dysfunction was a notable side effect in women of childbearing age. Most cases were reversible, resolving in many patients during treatment and in all patients who stopped therapy. Experts recommend fertility counseling before treatment to help patients understand and manage potential reproductive risks.