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

Objective: To 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.
Background: Anti-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.
Methods: This 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.
Results: Included 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.
Conclusions: Our 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.
(© 2024 American Headache Society.)