Abstract Objective Assess the long‐term efficacy and safety of erenumab in patients with chronic migraine with acute medication overuse. Background Overuse of acute medication in patients with chronic migraine has been linked to greater pain intensity and disability and may diminish the effectiveness of preventive therapies. Methods This 52‐week open‐label extension study followed a 12‐week double‐blind placebo‐controlled study in which patients with chronic migraine were randomized 3:2:2 to placebo or once‐monthly erenumab 70 mg or 140 mg. Patients were stratified by region and medication overuse status. Patients received erenumab 70 mg or 140 mg throughout or switched from erenumab 70 to 140 mg (based on protocol amendment to augment safety data at higher dose). Efficacy was assessed in patients with and without medication overuse at parent study baseline. Results Of 609 patients enrolled in the extension study, 252/609 (41.4%) met the criteria for medication overuse at parent study baseline. At Week 52, the mean change in monthly migraine days from parent study baseline was −9.3 (95% confidence interval: −10.4, −8.1 days) in the medication overuse subgroup versus −9.3 (−10.1, −8.5 days) in the non‐medication overuse subgroup (combined erenumab doses); proportion of patients achieving ≥50% reduction in monthly migraine days at Week 52 was 55.9% (90/161; 48.2%, 63.3%) versus 61.3% (136/222; 54.7%, 67.4%), respectively. Among baseline users of acute migraine‐specific medication, the mean change in monthly migraine‐specific medication days at Week 52 was −7.4 (−8.3, −6.4 days) in the medication overuse subgroup versus −5.4 (−6.1, −4.7 days) in the non–medication overuse subgroup. Most patients (197/298; 66.1%) in the medication overuse subgroup transitioned to non‐overuse status by Week 52. Erenumab 140 mg was associated with numerically greater efficacy than erenumab 70 mg across all endpoints. No new safety signals were identified. Conclusion Long‐term erenumab treatment demonstrated sustained efficacy and safety in patients with chronic migraine with and without acute medication overuse.
Timing and durability of response to erenumab in patients with chronic migraine
Abstract Background Erenumab is a human anti‐calcitonin gene‐related peptide receptor monoclonal antibody approved for migraine prevention. We sought to further assess the temporal patterns of response to erenumab in patients with chronic migraine (CM), specifically the onset and sustainability of monthly migraine day (MMD) response. Methods This is a post hoc analysis of a 12‐week, randomized, double‐blind, placebo‐controlled study of erenumab for migraine prevention in patients with CM (≥15 headache days/month, including ≥8 migraine days/month). Onset and sustainability were assessed according to MMD reduction from baseline, with the following response categories: responders (≥50% reduction), partial responders (≥30% and <50%), or nonresponders (<30%). Results Among the erenumab 140 mg group ( n = 187), 54.0% (101/187) achieved a response at any month during the study with a median time to onset of monthly response of 1 month. This improvement was maintained in most patients with continued treatment. An initial response was achieved at Month 1 by 28.3% (53/187) of patients; 69.8% (37/53) of whom maintained a response at Months 2 and 3. Although many patients responded early, some patients required longer treatment to achieve a response; 79.4% (27/34) of initial partial responders and 21.0% (21/100) of initial nonresponders subsequently achieved a response. Similar findings were observed for the erenumab 70mg group ( n = 188). Conclusion A majority of erenumab‐treated patients with CM who achieved an initial response at Month 1 sustained this benefit. Many patients responded later with continued treatment. Our data support recommendations to assess outcomes after ≥3 months of preventive treatment with erenumab in CM.