The use of onabotulinumtoxinA every 12 weeks over a 2-year period was found to be safe and effective for headache prevention in patients with chronic migraine in a multicenter open-label prospective study published in the Journal of Headache and Pain.
Adult patients with chronic migraine (n=373) were given 9 treatments of 155 units of onabotulinumtoxinA every 12 weeks for 108 weeks.
The study’s primary outcome was the reduction in headache days at the 108-week follow-up. In addition, headache day reductions at the 60-week follow-up and change in the 6-item Headache Impact Test score comprised the secondary outcome.
At 24 weeks, investigators allowed for the addition or change of oral preventive treatment, which occurred in 6.1% of participants. An average of 22.0±4.8 headache days per month were reported at baseline.
At the 60- and 108-week follow-ups, study participants experienced a reduction in headache days compared with baseline (–9.2 days and – 10.7 days, respectively; P <.0001). In addition, there were improvements in Headache Impact Test-6 scores at 108 weeks (– 7.1-point change; P <.0001).
One or more treatment-emergent adverse event was reported by 18.3% of participants, with neck pain being the most frequently reported (4.1%). Only 1 patient reported a rash, which was categorized as a serious treatment-related adverse event. No deaths occurred during the study or during follow-up.
This study lacked a placebo or active comparator arm, which reduces the ability to determine the treatment’s superiority or inferiority in terms of efficacy. In addition, the open-label nature of this study in combination with its long-term follow-up may have introduced unintentional bias.
“Combination of oral preventive treatment with long-term onabotulinumtoxinA treatment may be helpful in supporting people with [chronic migraine]” to achieve a maximized treatment response and long-term maintenance of headache improvement, concluded the study authors.
Blumenfeld AM, Stark RJ, Freeman MC, Orejudos A, Manack Adams A. Long-term study of the efficacy and safety of onabotulinumtoxinA for the prevention of chronic migraine: COMPEL study. J Headache Pain. 2018;19(1):13.