The addition of calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) to onabotulinumtoxinA for chronic migraine (CM) was associated with clinically meaningful benefits when assessing headache frequency as well as migraine-related disability, according to the findings of a study published in Pain and Therapy.

Since both therapies have been found to be safe and effective individually, the authors aimed to investigate whether the combination of onabotulinumtoxinA and CGRP mAbs would safely improve outcomes for patients with CM. “This retrospective, longitudinal chart review included adults with chronic migraine treated at 1 clinical site with ≥2 consecutive cycles of onabotulinumtoxinA and ≥1 month of subsequent combination treatment with CGRP mAbs,” the authors explained.

Patient charts were reviewed for safety, tolerability, and outcome measures at baseline (when mAb was prescribed) and for up to 4 visits (3, 6, 9, and 12 months). Outcome measures included monthly headache days (MHDs), intensity of headaches, as well as migraine-related disability (MIDAS).

The analysis included 257 patients (mean age, 50 years; 82% female); average MHDs were 21.5 prior to onabotulinumtoxinA initiation and 12.1 prior to the addition of CGRP mAb therapy. Of the total patients, 78% were prescribed erenumab, 16% galcanezumab, and 6% fremanezumab.

Data analysis revealed that CGRP mAbs were discontinued more frequently than onabotulinumtoxinA (23% vs 3%); the most common reason for discontinuing treatment was lack of reimbursement. Adverse events were reported by 28% of patients, the most common being constipation (9%), which occurred most frequently in erenumab-treated patients.

“Compared with onabotulinumtoxinA alone (baseline), MHDs decreased significantly at all visits (mean decrease: 3.5–4.0 MHDs over ~6-12 months of combination treatment); 45.1% of patients had clinically meaningful improvement in migraine-related disability (≥5-point reduction in MIDAS score) after ~ 6 months,” the study authors reported.

According to the findings of this study, the combination of onabotulinumtoxinA with CGRP mAbs was well tolerated and improved outcomes for patients suffering from CM. “Additional real-world and controlled trials should be considered to further assess safety and quantify the additive or synergistic benefit of this multimodal treatment paradigm for people with CM,” the authors concluded.

Disclosure: This research was supported by AbbVie. Please see the original reference for a full list of disclosures.


Blumenfeld AM, Frishberg BM, Schim JD, et al. Real-world evidence for control of chronic migraine patients receiving CGRP monoclonal antibody therapy added to onabotulinumtoxinA: A retrospective chart review. [published online April 21, 2021]. Pain and Therapy. doi: 10.1007/s40122-021-00264-x