Study design, patients, and treatments
A description of the randomized, double-blind, placebo-controlled, parallel-group phase 3 HALO CM study (NCT02621931), which included a screening visit, 28-day pretreatment period, 12-week treatment period, and final evaluation (week 12), has been published previously [16].
Briefly, adults aged 18 to 70 with a history of migraine (according to the International Classification of Headache Disorders, third edition [ICHD-3] beta criteria [17]) for ≥12 months prior to screening and prospectively confirmed CM (headache on ≥15 days and ≥8 days fulfilling ICHD-3 beta criteria for migraine, probable migraine, or use of triptan or ergot medications) during the 28-day pretreatment baseline period were eligible to participate [16]. Patients who used opioids (including codeine) or barbiturates on >4 days per month were excluded from the trial. Additional inclusion and exclusion criteria are provided in a Table in Additional file 1.
Eligible patients were randomized 1:1:1 to receive subcutaneous injections of either fremanezumab quarterly (675 mg of fremanezumab at baseline and placebo at weeks 4 and 8), fremanezumab monthly (675 mg of fremanezumab at baseline and 225 mg at weeks 4 and 8), or placebo (matching placebo at baseline and at weeks 4 and 8) [16].