SpringWorks Therapeutics Announces Long-Term Efficacy and Safety Data from Phase 3 DeFi Trial of OGSIVEO® (nirogacestat) in Adults with Desmoid Tumors to be Presented at the Connective Tissue Oncology Society (CTOS) 2024 Annual Meeting

Core Insights - Long-term follow-up data from the Phase 3 DeFi trial of nirogacestat in adults with progressing desmoid tumors indicate further reductions in tumor size, increased objective response rate (ORR), and sustained improvement in symptoms, with a median treatment duration of approximately 3 years [1][2][3] Efficacy and Safety - The long-term treatment with nirogacestat resulted in an ORR of 45.7%, with 34.3% achieving partial responses (PRs) and 11.4% achieving complete responses (CRs) [4] - 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 [4] - Patient-reported outcomes (PROs) showed early and sustained improvements in pain and physical functioning, with significant benefits reported by patients [5][6] Clinical Trial Details - The DeFi trial involved 142 patients, with 70 receiving nirogacestat and 72 receiving placebo, focusing on progression-free survival (PFS) as the primary endpoint [8] - The ongoing open-label extension phase allows for continued assessment of nirogacestat's efficacy and safety beyond the double-blind portion of the study [8] Subgroup Analysis - A post-hoc analysis indicated that nirogacestat treatment led to consistent improvements in PFS, ORR, and PROs across various subgroups with poor prognostic factors [6] - The ORR risk difference between nirogacestat and placebo ranged from 18.1% to 56.0%, favoring nirogacestat [6] Patient Population Insights - Desmoid tumors are rare, aggressive tumors primarily affecting individuals aged 20 to 44, with a higher prevalence in females [9] - The estimated annual incidence of new cases in the U.S. is between 1,000 and 1,650 [9] Company Overview - SpringWorks Therapeutics is focused on developing treatments for severe rare diseases and cancer, with OGSIVEO (nirogacestat) being its first FDA-approved therapy for desmoid tumors [10][16] - The company is also exploring nirogacestat for other indications, including ovarian granulosa cell tumors and multiple myeloma [11]