Nirogacestat, a γ-Secretase Inhibitor for Desmoid Tumors.

BACKGROUND Desmoid tumorS are rare, locally aggressive, highly recurrent soft-tissue tumors without approved treatments. METHODS We conducted a phase 3, international, double-blind, randomized, placebo-controlled trial of nirogacestat in adults with progressing desmoid tumors according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Patients were assigned in a 1:1 ratio to receive the oral y-secretase inhibitor nirogacestat (150 mg) or placebo twice daily. The primary end point was progression-free survival. RESULTS From May 2019 through August 2020, a total of 70 patients were assigned to receive nirogacestat and 72 to receive placebo. Nirogacestat had a significant progression-free survival benefit over placebo (hazard ratio for disease progression death, 0.29; 95% confidence interval, 0.15 to 0.55; P<0.001); the likelihood being event-free at 2 years was 76% with nirogacestat and 44% with placebo. Between-group differences in progression-free survival were consistent across prespecified subgroups. The percentage of patients who had an objective response was significantly higher with nirogacestat than with placebo (4196 vs. 896; P<0.001), with a median time to response of 5.6 months and 11.1 months, respectively; the percentage of patients with a complete response was 7% and 096, respectively. Significant between-group differences in secondary patient-reported outcomes, including pain, symptom burden, physical or role functioning, and health-related quality of life, were observed (P50.01). Frequent adverse events with nirogacestat included diarrhea (in 84% of the patients), nausea (in 54°/o), fatigue On 51%), hypophosphatemia On 42°6), and maculopapular rash (in 3296); 95% adverse events were of grade 1 or 2. Among women of childbearing potential receiving nirogacestat, 27 of 36 (75%) had adverse events consistent with ovarian dysfunction, which resolved in 20 women (7496). CONCLUSIONS Nirogacestat was associated with significant benefits with respect to progressionfree survival, objective response, pain, symptom burden, physical functioning, role functioning, and health-related quality of life in adults with progressing desmoid tumors. Adverse events with nirogacestat were frequent but mostly low grade. (Funded by SpringWorks Therapeutics; DeFiCIinica]Trials.gov number, NCT03785964.). [ABSTRACT FROM AUTHOR]