To evaluate real-world safety and potential benefits of adding CGRPmAb to onabotulinumtoxinA treatment in patients with CM.

Combination use of onabotulinumtoxinA and CGRPmAbs has potential to be more effective than each therapy alone for CM prevention. In the primary analysis cohort, records from 257 adults with CM receiving onabotulinumtoxinA along with CGRPmAb showed that combination therapy was well tolerated and associated with additional reductions in monthly headache days (MHDs) and migraine-related disability (MIDAS). To better understand the applicability of these findings, a sensitivity analysis was conducted in a cohort aligned to the AHS position statement (Headache. 2019;59:1).

This was a retrospective, longitudinal chart review of adults with CM treated at 1 clinic (October 2018–November 2019) with ≥2 consecutive onabotulinumtoxinA cycles before ≥1 month of onabotulinumtoxinA plus CGRPmAb (erenumab, fremanezumab, or galcanezumab) combination treatment. Patients in the sensitivity analysis  cohort had ≥4 MHDs and MIDAS >11 or HIT-6 >50 score at baseline. Charts at CGRPmAb prescription visit (baseline) and ≤4 subsequent visits over ≤~12 months were reviewed for adverse events (AEs), discontinuations, MHDs, and MIDAS.

Of 300 charts reviewed, 172 patients met AHS criteria (mean age: 50 years; 83% women); 78% received erenumab (galcanezumab 17%; fremanezumab 5%). More patients discontinued CGRPmAbs than onabotulinumtoxinA (24% vs 3%). AEs were reported in 27% of patients; the most common was constipation (10%). Mean MHDs were 21.4 before initiating onabotulinumtoxinA and 13.4 before adding CGRPmAb (baseline). MHDs significantly decreased from baseline at all visits (mean decrease at ~6 months: 3.9 days [95% CI: −5.0,−2.7]). After ~6 months, ≥58% had clinically meaningful MIDAS improvement (≥5-point decrease).

Combination use of onabotulinumtoxinA and CGRPmAb demonstrated clinically meaningful improvements in headache frequency and migraine-related disability compared with onabotulinumtoxinA alone in patients with high baseline MHDs and disability treated according to AHS guidance.