Core Insights - SpringWorks Therapeutics announced long-term efficacy and safety data from the Phase 3 DeFi trial of OGSIVEO® (nirogacestat) for treating adults with progressing desmoid tumors, published in the Journal of Clinical Oncology [1][2] - The trial demonstrated that longer-term treatment with OGSIVEO is associated with further reductions in tumor size, increased objective response rates, and sustained improvement in patient-reported outcomes [1][3] Efficacy and Safety Data - The long-term follow-up data showed that the objective response rate (ORR) improved from 34.3% in year 1 to 45.7% for patients treated for up to 4 years, with additional complete and partial responses observed [3] - The median best percent reduction in target tumor size was −32.3% at year one and −75.8% for patients completing at least four years of treatment [3] - Improvements in patient-reported outcomes were noted early and sustained with up to 45 months of treatment [3] Adverse Events - The incidence and severity of treatment-emergent adverse events (TEAEs) decreased over the treatment duration, with common adverse events including diarrhea, ovarian toxicity, and rash [4][19] - Serious adverse reactions occurred in ≥2% of patients, with ovarian toxicity reported in 4% [19] Trial Design and Patient Demographics - The DeFi trial was a global, randomized, multicenter, double-blind, placebo-controlled study involving 142 patients, with a primary endpoint of progression-free survival [5][6] - Desmoid tumors are rare, locally aggressive tumors, primarily affecting individuals aged 20 to 44, with a higher prevalence in females [7] Product Information - OGSIVEO® (nirogacestat) is an oral gamma secretase inhibitor approved for treating adult patients with progressing desmoid tumors requiring systemic treatment [8] - The drug has received Orphan Drug designation from the FDA and EMA for this indication [8]