Effects of onabotulinumtoxinA treatment in chronic migraine patients with and without daily headache at baseline: Results from the COMPEL Study

Background: OnabotulinumtoxinA is effective in preventing chronic migraine (CM); however, the benefit of onabotulinumtoxinA in patients with CM with daily headache is unknown because these patients are typically excluded from clinical trials. This subanalysis of the COMPEL Study assessed the efficacy and safety of onabotulinumtoxinA in people with CM with and without daily headache. Methods: In total, 715 patients received onabotulinumtoxinA 155 U with or without concomitant oral preventive treatment. Patients who had complete daily diary records for the 28 days of the baseline period were stratified based on daily headache status. The primary outcome variable was reduction in headache-day frequency per 28-day period at 108 weeks (after 9 treatment cycles) relative to baseline. Exploratory outcomes included moderate to severe headache days, migraine disability (using the Migraine Disability Assessment [MIDAS] questionnaire), and health-related quality of life (Migraine-Specific Quality-of-Life Questionnaire v2 [MSQ]). Adverse events and their relatedness were recorded. Results: Overall, 641 patients had complete daily diary records at baseline. In patients with daily headache (n = 138) versus without (n = 503), treatment with onabotulinumtoxinA was associated with a significant mean (SD) reduction in 28-day headache-day frequency relative to baseline at week 108 (- 10.5 [9.2] vs - 12.2 [6.7], respectively; both P < 0.001) with no significant between-group difference (P = 0.132). The mean (SD) reduction in moderate to severe headache days at week 108 was significant in patients with and without daily headache (- 11.5 [9.4] and - 9.9 [6.4]; P < 0.001) with no significant between-group difference (P = 0.153). Mean (SD) MIDAS scores significantly improved from baseline at week 108 (- 43.3 [73.4] and - 43.6 [46.7]; both P < 0.001), with no significant between-group difference (P = 0.962). Similarly, mean (SD) MSQ subscale scores significantly improved from baseline at week 108 for patients with and without daily headache. OnabotulinumtoxinA was well tolerated in patients with and without daily headache. Conclusion: Results indicate that onabotulinumtoxinA is associated with reductions from baseline in headache-day frequency and improvements in disability and quality of life for up to 108 weeks in people with CM with daily headache; however, a longer duration of treatment was required to fully realize the treatment effect on headache. No new safety concerns were identified.