Effectiveness of dual migraine therapy with CGRP inhibitors and onabotulinumtoxinA injections: case series

Aims: Clinical trials for calcitonin gene-related peptide (CGRP) inhibitors excluded the concomitant use of onabotulinumtoxinA; thus, there is a lack of efficacy and safety data of the combined therapies. Our study aims to examine the effectiveness of CGRP inhibitors with onabotulinumtoxinA by evaluating migraine reductions in headache days and severity.

Methods: Seventeen patients with chronic migraines were identified who had a partial or poor response to onabotulinumtoxinA, and were placed on dual therapy with a CGRP inhibitor. Patients' initial headache days and severity ratings were compared to final values taken 1-6 months after adding the CGRP inhibitor to their treatment regime. Comparisons between headache days and severity ratings prior to and during dual treatment were performed utilizing the Kruskal-Wallis test. The significance was set at p < 0.05.

Results: Of 17 patients (16F/1 M), n = 9 were taking fremanezumab, n = 4 were taking erenumab, and n = 4 were taking galcanezumab. Patients' average headache days per month was reduced from 27.6 ± 4.8 initially to 18.6 ± 9.4 post-treatment (p = 0.00651), and their average pain level was reduced from 8.4 ± 1.4 out of 10 to 5.4 ± 2.5 (p = 0.00074). No serious adverse side effects were reported from patients on dual therapy.

Conclusion: Patients with suboptimal response to onabotulinumtoxinA may benefit from CGRP inhibitors' addition to their migraine regimens. Placebo-controlled randomized studies are advised to corroborate this finding.