(P 368) ASSESSMENT OF PAIN DIAGNOSIS AND PAIN MEDICATION USE IN ADULTS TREATED WITH NIROGACESTAT: A UNITED STATES REAL-WORLD ANALYSIS

Objective: Pain is among the most debilitating symptoms of desmoid tumors (DT). Nirogacestat (niro) demonstrated significant and clinically meaningful pain reduction in adults with progressing DT in the phase 3 DeFi trial. This analysis assessed the prevalence of pain diagnoses (dx) and pain medication use (PMU) in adult patients before and after initiating a niro prescription (Rx).

Methods: A US claims database (data window: 27AUG2023-31DEC2024) was used to identify the first-filled niro Rx date as the index date. Pain dx and PMU were assessed in a continuous enrollment (CE) period of 3- and 6-month pre- (baseline, BL) and 3- and 6-month post-index (follow-up, FU), with ≥2 filled niro Rxs as eligible for the analysis. Pain dx were identified using pain-specific ICD10 codes. PMU was assessed for patients who filled ≥1 Rx for opioids or non-steroidal anti-inflammatory drugs (NSAIDs). Subgroups included sex and age (≤30 vs >30), excluding unknown. Opioid dose reduction in FU (relative to BL) was calculated as a decrease in total Morphine Milligram Equivalent (MME) dose (MME=strength per unit x number of units x MME conversion factor).

Results: In the 3-month BL and FU period, 155 patients were eligible for the pain dx analysis, of which 80 (52%) had a pain dx in BL. In FU, 36% (29/80) no longer had a pain dx [female: 32% (18/56) vs male: 45% (10/22); age ≤30: 45% (5/11) vs age>30: 35% (24/69)]. Of 314 patients eligible for the PMU analysis, 125 (40%) filled ≥1 Rx for a pain medication in BL [opioids: n=86, NSAIDs: n=48]. In FU, 37% (32/86) did not fill an opioid Rx [female: 39% (22/57) vs male: 33% (9/27); age ≤30: 43% (6/14) vs age>30: 36% (26/72)]. Of 52 patients with opioid use and data for MME in FU, 37% (19/52) had a dose reduction. Also, 58% (28/48) of patients did not fill an Rx for NSAIDs in FU.

6-month BL and FU data will be presented.

Conclusion: This analysis showed a clinically relevant reduction in pain dx for patients during 3 months of niro treatment. These results are consistent with the significant and clinically meaningful benefit of pain reduction associated with niro in DeFi. The reduction in opioid Rx and dose during 3 months of niro treatment may help reduce the risk of chronic opioid use.