Persistence, effectiveness, and tolerability of anti‐calcitonin gene–related peptide monoclonal antibodies in patients with chronic migraine

ObjectiveTo evaluate, in patients with chronic migraine (CM) in real‐world conditions, the persistence, effectiveness, and tolerability of erenumab, fremanezumab, and galcanezumab anti‐calcitonin gene–related peptide (anti‐CGRP) monoclonal antibodies (mAbs) and the persistence and effects of switching.BackgroundAnti‐CGRP mAbs represent a novel therapeutic approach to the management of CM; however, real‐world data on persistence, effectiveness, and tolerability, especially after switching, are scarce.MethodsThis was a retrospective observational cohort study including all patients with CM treated with erenumab, fremanezumab, and/or galcanezumab in a tertiary hospital between January 2019 and December 2022. Treatment persistence was measured as the number of days between treatment start and end dates or the end of follow‐up and also as a percentage of persistent patients at 3, 6, and 12 months; effectiveness as a ≥50% reduction in monthly migraine days (MMD); and tolerability as the number and type of adverse events.ResultsIncluded were 281 patients (383 treatments) with CM (91.5% [257/281] female) receiving anti‐CGRP mAbs. Median (interquartile range [IQR]) treatment persistence was 267 (103–550) days. At 12 months, persistence was greater for the first (66.7%) compared to the second (49.8%) and third (37.2%) anti‐CGRP mAb treatments (hazard ratio [HR] = 1.93, 95% confidence interval [CI]: 1.35–2.74; HR = 2.75, 95% CI: 1.69–4.47, respectively). Persistence minimum observed median (IQR) was also greater for the first (291 [112–594] days) compared to both the second (188 [90–403] days; p < 0.001) and third (167 [89–352] days; p < 0.001) anti‐CGRP mAb treatments. For the first anti‐CGRP mAb treatment, there were no differences in persistence among the different drugs. In terms of effectiveness of the first, second, and third anti‐CGRP mAb treatments, a ≥50% reduction in MMD was achieved by 57.6% (117/203), 25.0% (11/44), and 11.8% (2/17) of patients, respectively, at 3 months, and by 55.8% (87/156), 29.6% (8/27), and 12.5% (1/8) of patients, respectively, at 6 months. At 12 months, no significant effectiveness differences were observed among anti‐CGRP mAb treatments. As for tolerability, 55 adverse events were reported by 43 (15.3%) patients, mostly mild and leading to treatment discontinuation in only 14 (5.0%) patients. The most common adverse events were constipation, injection site reaction, and pruritus. Erenumab patients (3%, 3/99) experienced a higher rate of discontinuation for constipation.ConclusionsOur findings showed a 12‐month higher treatment persistence with the use of a first anti‐CGRP mAb treatment when the switch to a second treatment was due to ineffectiveness or severe side events. This persistence was lower after a second or third anti‐CGRP. Additionally, in terms of effectiveness, the first anti‐CGRP treatment achieved a higher response in terms of ≥50% reduction in MMD; however, some patients may benefit from a switching strategy. Finally, the tolerability profile for anti‐CGRP mAbs was favorable. Further studies are needed to identify predictors of response after switching from the first anti‐CGRP mAb treatment.