Efficacy and Tolerability of Calcitonin Gene-Related Peptide-Targeted Monoclonal Antibody Medications as Add-on Therapy to OnabotulinumtoxinA in Patients with Chronic Migraine

Abstract

Background: We examined the efficacy and tolerability of calcitonin gene-related peptide-targeted monoclonal antibodies (CGRP-targeted mAbs) as add-on therapy for patients with chronic migraine (CM) undergoing treatment with onabotulinumtoxinA (onabot) who require additional preventive therapy.

Methods: We reviewed medical records of patients with CM receiving treatment with onabot who were subsequently prescribed a CGRP-targeted mAb medication. The primary outcome was the change in number of monthly headache days (MHDs) reported. Secondary outcomes were change in headache pain severity, discontinuation due to lack of tolerability, and severe adverse events.

Results: Of 153 patients, 111 (72.5%) reported a decrease in either MHDs or headache pain severity, with documentation of MHDs in 66 patients. Among these 66 patients, the average number of MHDs before initiation of onabot treatment was 25.7. After onabot treatment, an average decrease of 10.9 MHDs was reported (P < 0.001). After the addition of a CGRP-targeted mAb medication, patients experienced a further decrease of 5.7 MHDs (P < 0.001). With combined therapy, patients reported a total decrease of 16.6 MHDs (P < 0.001). Adverse effects occurred in 13 patients (8.5%) after addition of the CGRP-targeted mAb and included constipation, injection site reaction, and fatigue. No serious adverse events were reported.

Conclusion: Adding a CGRP-targeted mAb to onabot in patients with CM was associated with further reductions in MHDs without major tolerability issues across a range of mAbs. This retrospective review supports the conduct of a well-designed double-blind study adding a CGRP-targeted mAb or placebo to onabot.

Keywords: Calcitonin Gene–Related Peptide; Chronic Migraine; Efficacy; OnabotulinumtoxinA; Tolerability.