Safety and Tolerability of 3 CGRP Monoclonal Antibodies in Practice: A Retrospective Cohort Study

Abstract

Objective

We sought to assess the safety and tolerability of 3 calcitonin gene-related peptide (CGRP) monoclonal antibodies in patients with chronic migraine who have failed multiple classes of migraine preventive therapies.

Background

CGRP is an important neuromodulator implicated in the pathogenesis of migraine. They are approved for the treatment of episodic and chronic migraine. In current clinical practice, CGRP monoclonal antibodies are used in patients who have failed multiple preventive agents, but safety, tolerability, and efficacy have not been well described in real-world populations outside of clinical trials.

Methods

This was a single-center, observational, retrospective study in adults with chronic migraine treated with a CGRP monoclonal antibody between May 1, 2018 and September 30, 2019. Charts were reviewed at 0, 3, and 6 months after treatment.

Results

From May 1, 2018 to September 30, 2019, 77 patients with chronic migraine were prescribed 90 treatment trials of a CGRP monoclonal antibody. Patients reported adverse outcomes in 2/5 (40.0%) with erenumab 70 mg, 32/46 (69.6%) with erenumab 140 mg, 8/16 (50.0%) with fremanezumab, and 15/23 (65.2%) with galcanezumab. The most frequent adverse effects were constipation and injection site reactions. Adverse effects leading to discontinuation were reported as follows: erenumab 70 mg 1/5 (20.0%), erenumab 140 mg 10/46 (22.7%), fremanezumab 1/16 (6.3%), and galcanezumab 1/23 (4.3%), with 13/90 (14.4%) discontinuation rate overall. The most frequent reasons for discontinuation were lack of improvement in 17/90 (18.9%) and constipation in 4/90 (4.4%). A 50% or greater reduction in the number of severe headache days per month was achieved for 32/66 (48.5%) at 3 months and 17/48 (35.4%) at 6 months.

Conclusions

In patients with chronic migraine, the 3 CGRP monoclonal antibodies were well tolerated, and reduced the number of severe headache days.