To evaluate the benefit of adding large molecule anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) to onabotulinumtoxinA (OBT-A) in patients with partially-controlled chronic migraine.

Chronic migraine (CM) is a highly-prevalent and debilitating disorder that leads to personal, social, and economic burdens. Both OBT-A and mAbs are effective in chronic migraine prevention. The use of combination therapy has not been studied but may prove more effective than either monotherapy.

We performed a retrospective chart review of adult patients with chronic migraine treated with combined therapy of OBT-A and mAbs. Patients who received 2 courses of OBT-A with at least 30% reduction in migraine headache days (MHDs), continued to suffer from at least 3 MHDs per month and were started on mAbs were included in the analysis. Data including monthly MHDs, total headache days (THDs), headache severity, and patient disability level were recorded at baseline and 3 months after starting a mAb.

A total of 137 patients were included in the analysis. Average monthly MHDs was 10.7 days at baseline. Three months after initiation of mAb treatment, average monthly MHDs was 4.9. Average THDs at 3 months was 16.7 days compared to 24.3 days at baseline. At baseline, 38 patients reported high disability compared to 16 at 3 months. No serious side effects were reported.

Combined therapy with OBT-A and mAbs was associated with substantial reduction in monthly MHDs and THDs. Although descriptive in nature, this study indicates that dual therapy with OBT-A and mAbs may be beneficial in reducing MHDs and THDs and improving quality of life in CM patients.