OnabotulinumtoxinA improves quality of life and reduces impact of chronic migraine over one year of treatment: Pooled results from the PREEMPT randomized clinical trial program

BACKGROUND: Chronic migraine (CM) is associated with high impact and reduced health-related quality of life (HRQoL). METHODS: Patients with CM from PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) were randomized (1:1) to receive onabotulinumtoxinA or placebo for two 12-week cycles in the double-blind (DB) phase, followed by three 12-week cycles of open-label (OL) onabotulinumtoxinA (onabotulinumtoxinA/onabotulinumtoxinA (O/O) and placebo/onabotulinumtoxinA (P/O) groups, respectively). HRQoL endpoints were assessed over 56 weeks using the Headache Impact Test (HIT-6) and the Migraine-Specific Quality of Life Questionnaire (MSQ). HIT-6 score reductions ≥2.3 and ≥5 denoted between-group minimally important difference and within-patient clinically meaningful response, respectively. RESULTS: A total of 1236 participants (O/O, n = 607; P/O, n = 629) participated in both phases. The DB phase showed significantly reduced HIT-6 and MSQ for onabotulinumtoxinA versus placebo (all p < 0.001). The OL phase showed significantly reduced HIT-6 for O/O versus P/O at weeks 28, 36, and 48, but not 56. All three MSQ domains showed improved HRQoL relative to baseline, but only the role restrictive domain showed a significant difference between O/O and P/O at week 56. CONCLUSIONS: Benefits of onabotulinumtoxinA on HRQoL versus baseline persisted throughout the OL phase. Statistical superiority in favor of O/O was demonstrated for HIT-6 through 48 weeks and for MSQ (role restrictive) at 56 weeks.