Over the course of 112 weeks, treatment with erenumab (Aimovig; Amgen/Novartis), an FDA-approved monoclonal antibody that targets calcitonin gene-related peptide (CGRP), demonstrated sustained efficacy in both group and individual responder rates among patients with episodic migraine who previously failed 2 to 4 prior preventatives.1
In total, 240 of 246 individuals (97.6%) who completed the 12-week double-blind treatment phase (DBTP) of the LIBERTY study (NCT03096834) entered the open-label extension phase (OLEP), which assigned patients to erenumab 140-mg monthly for up to 3 years. Of these, 118 were continuing previous erenumab treatment and 122 switched from placebo.
Led by Michel D. Ferrari, MD, professor of neurology, Leiden University Medical Center, the final analysis included 181 of the 240 original cohort who reached 112 weeks of treatment. Lack of efficacy, participant decision, and adverse events (AEs) accounted for 44%, 37%, and 12% of the reasons for discontinuation from erenumab, respectively. New therapy for study indication (3.4%), and pregnancy and physician decision (1.7% each) rounded out the others.
Ferrari and colleagues concluded that erenumab is a “novel, effective and safe preventive treatment option for difficult-to-treat migraine.”
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Investigators observed a reduction of at least 50% in monthly migraine days (MMDs) in 46.7% of patients (64 of 137) at week 64 and 57.2% (99 of 173) at week 112. Furthermore, 23.4% (32 of 137) and 30.6% (53 of 173) at weeks 64 and 112, respectively, had at least a 75% reduction in MMDs. Achievement of 100% reduction in baseline MMDs was observed in 12.4% (17 of 137) at week 64 and 16.2% (28 of 173) at week 112. From baseline to week 112, the mean change in MMDs for the continuous erenumab group was –3.9 (standard deviation [SD], 5.5]) and for those who switched from placebo to erenumab in the OLEP was –4.6 (SD, 4.6) days.
In total, 68.6% (24 of 35) of participants who were previously on erenumab and had at least a 50% response maintained their responder status at more than half of the visits during the 2 years of OLEP. Notably, 42.9% (15 of 35) maintained their responder status for at least 80% of the visits. For those who saw at least a 50% response after switching from placebo to erenumab (17 of 121 [13.9%]), 70.6% (12 of 17) remained at least a 50% responder for at least half the visits during the 2 years of OLEP and 41.2% (7 of 17) for at least 80% of the visits.
Erenumab demonstrated an impact even for nonresponders who continued treatment, with 19.5% (16 of 82) converting to at least a 50% response rate for at least half of the visits and 7.3% (6 of 82) converted at the same rate for at-least 80% of visits. The treatment showed an even greater impact among the 103 nonresponders from the placebo arm at week 12. Of these, 42.7% (n = 44) and 17.5% (n = 18) became at least 50% responders in at least half or 80% of the visits, respectively, at the end of the analysis.
Erenumab’s safety was similar to what was previously observed in clinical trials, with no new safety signals. Over the 2-year OLEP, 86.3% of participants experienced treatment-emergent AEs, a slight increase from year 1 (80.8%). Frequently reported AEs found in at least 10% of patients included nasopharyngitis, influenza, and back pain. Hypersensitivity was reported in 1 participant continuing erenumab in the OLEP. Notably, neither treatment group varied during the OLEP regarding laboratory parameters, vital signs, or electrocardiogram parameters.
In January, additional data from LIBERTY indicated that erenumab has a positive impact on patient-reported outcomes of migraine-related functional and physical impairment (PI), work productivity, and everyday activities. In that subanalysis, erenumab significantly improved scores in Migraine Physical Function Impact Diary (MPFID) PI and everyday activities (EA) subsets. When compared to placebo, patients on erenumab experienced a score difference of –3.5 (95% CI, –5.7 to –1.2; P = .003) in MPFID-PI score and a difference of –3.9 (95% CI, –6.1 to –1.7; P <.001) in MPFID-EA score at 12 weeks.2