Early response to eptinezumab indicates high likelihood of continued response in patients with chronic migraine

BACKGROUND: A clinical ability to describe the response trajectory of patients receiving preventive migraine treatment could expedite and improve therapeutic management decisions. This post hoc analysis of the PROMISE-2 study evaluated the consistency and predictive power of Month 1 treatment response on later response in patients with chronic migraine. METHODS: PROMISE-2 was a double-blind, placebo-controlled trial that randomized adults with chronic migraine to eptinezumab 100 mg, 300 mg, or placebo administered IV every 12 weeks for up to 24 weeks (2 infusions over 6 study months). Migraine responder rates (MRRs) were calculated from monthly migraine days over 4-week intervals compared with baseline. Patients were grouped by MRR during Month 1 (< 25%, 25–< 50%, 50–< 75%, and ≥ 75%), with the number of subsequent study months (Months 2–6) with ≥50% and ≥ 75% MRR calculated in each subgroup. A similar analysis was conducted using Patient Global Impression of Change (PGIC) rating to define Month 1 subgroups (very much improved, much improved, minimally improved, and no change/worse) and rates of very much improved or much improved PGIC during Months 2–6. RESULTS: In the eptinezumab 100 mg, 300 mg, and placebo groups, respectively, 194/356 (54.5%), 212/350 (60.6%), and 132/366 (36.1%) patients were ≥ 50% migraine responders during Month 1. More eptinezumab-treated patients were ≥ 75% migraine responders (100 mg, 110/356 [30.9%]; 300 mg, 129/350 [36.9%]; placebo, 57/366 [15.6%]) and more placebo-treated patients were < 25% migraine responders (eptinezumab 100 mg, 103/356 [28.9%]; 300 mg, 80/350 [22.9%]; placebo, 153/366 [41.8%]). Among patients who achieved ≥75% migraine response in Month 1, more than one-third attained ≥75% migraine response for all 5 subsequent study months and more than two-thirds achieved ≥75% migraine response for ≥3 months. More than two-thirds of those in the very much improved (PGIC) subgroup at Month 1 were much or very much improved for all 5 subsequent months. CONCLUSIONS: In this post hoc analysis of data from PROMISE-2, more eptinezumab-treated than placebo-treated patients were early (Month 1) responders, and most early responders went on to achieve a high level of response for at least half of the 24-week treatment period. Potential for later response in early non-responders was also observed. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02974153; registered November 23, 2016.