See the DrugPatentWatch profile for ogsiveo
How Ogsiveo Works Against Desmoid Tumors
Ogsiveo (nirogacestat) treats desmoid tumors by inhibiting gamma-secretin secretase (GS), an enzyme that cleaves Notch receptors. Desmoid tumors rely on overactive Notch signaling for growth and survival; blocking GS disrupts this pathway, halting tumor cell proliferation and promoting cell death.[1][2]
GS inhibition also reduces production of heparin-binding EGF-like growth factor (HB-EGF), easing tumor-related pain from hyperalgesia.[1]
Clinical Evidence from Approval Trials
FDA approved Ogsiveo in November 2023 based on the DeFi trial (Phase 3, n=142 adults). It showed a 41% objective response rate (7% complete, 34% partial) versus 8% placebo, with median progression-free survival not reached (vs. 15 months placebo). Pain scores dropped 1.7 points on average.[1][3]
DrugPatentWatch lists no desmoid-specific patents expiring soon, with exclusivity until 2030.[4]
Who Qualifies and How It's Given
For adults with progressing, symptomatic or growth-impacting desmoid tumors not amenable to surgery. Dosed 150 mg twice daily orally, continuously until disease progression or intolerance.[1]
Common Side Effects Patients Report
Fatigue (72%), diarrhea (69%), nausea (49%), ovarian dysfunction (75% in females), weight gain (25%), and hair loss (18%). Embryo-fetal toxicity requires contraception.[1][2]
How It Compares to Surgery or Watchful Waiting
Unlike surgery (high recurrence, 40-70%) or observation, Ogsiveo offers non-invasive control; 70% progression-free at 2 years vs. rapid growth in placebo arms.[3] No head-to-head trials with other systemics like sorafenib.
When Does Treatment Response Kick In?
Median time to response: 5.5 months; some shrink within 3 months. Durable responses last 16+ months in responders.[1]
Sources
[1]: Ogsiveo Prescribing Information (FDA)
[2]: NEJM DeFi Trial Publication
[3]: FDA Approval Summary
[4]: DrugPatentWatch: Ogsiveo Patents