(78) Sustained Reductions in Monthly Headache Days with Long-Term Eptinezumab Treatment for Chronic Migraine: Post-Hoc Analysis of the Phase 3 PREVAIL Study

Background: : The phase 3 PREVAIL study, a single-arm, open-label, long-term safety trial, demonstrated a favorable safety profile that aligned with other trials and showed reductions in migraine burden over a 2-year period for participants treated with eptinezumab.

Objective: : This post-hoc analysis of PREVAIL evaluated whether early clinical response (ie, ≥50% or ≥75% reduction in headache days within the first 1 or 2 doses) using headache frequency from the Migraine Disability Assessment (MIDAS) predicted long-term maintenance of response.

Methods: : PREVAIL was a single-arm, open-label trial that evaluated the long-term outcomes of eptinezumab treatment in adults aged 18 to 65 years with chronic migraine (CM). Participants received 300 mg of eptinezumab administered intravenously every 12 weeks. This post-hoc analysis assessed the proportion of participants with a ≥50% or ≥75% reduction in monthly headache days (MHDs), based on the reduction in MIDAS-derived headache frequency after the first (Weeks 1-12) or second (Weeks 13-24) dosing intervals, who sustained that reduction through the subsequent 12-week dosing intervals up to Week 84.

Results: : Out of the 128 participants enrolled in PREVAIL, 100 had complete MIDAS-derived headache frequency data at all time points through Week 84 and were included in this post-hoc analysis. Among the 78 (78%) participants who achieved ≥50% reduction in MHDs at Weeks 1-12, 78% (61) maintained that reduction through the subsequent dosing intervals up to Week 84. Likewise, of the 77 (77%) participants who attained ≥50% reduction in MHDs at Weeks 13-24, 83% (64) maintained that reduction through the remaining dosing intervals. For the participants with ≥75% reduction in MHD at Weeks 1-12 (63 participants [63%]) and Weeks 13-24 (55 participants [55%]), 54% (34) and 69% (38), respectively, maintained that reduction through the subsequent dosing intervals.

Conclusions: : More than half of the participants who achieved ≥50% or ≥75% reduction in MHDs following the first or second dose continued to experience reductions in headache frequency with ongoing eptinezumab treatment. This suggests that an early response may serve as a predictor of sustained response.

Sponsorship:: H. Lundbeck A/S (Copenhagen, Denmark)