An adjusted indirect comparison found no significant efficacy or safety differences between erenumab, fremanezumab, and eptinezumab for chronic migraine prevention, suggesting they are interchangeable CGRP-targeting therapeutic options.
No significant differencesThree CGRP peptide-targeting antibodies showed equivalent efficacy for ≥50% reduction in monthly migraine days within a 9.5% equivalence margin
What the researchers found
From 30 identified randomized clinical trials, three studies met inclusion criteria for indirect treatment comparison (one each for erenumab, fremanezumab, and eptinezumab). Using Bucher's method for adjusted indirect comparison:
- No statistically significant differences in the proportion of patients achieving ≥50% reduction in monthly migraine days between any of the three drugs
- Most of the 95% confidence intervals fell within the calculated equivalence delta margin (Δ = 9.5%)
- No relevant safety differences were found among the three drugs
- The drugs were assessed as probable clinical equivalents in terms of efficacy and safety for chronic migraine prevention
Why it matters
When multiple drugs in the same class are available, clinicians and formulary committees need to know whether they can be considered interchangeable. This study provides evidence that erenumab, fremanezumab, and eptinezumab are therapeutically equivalent for chronic migraine, meaning drug selection can be based on practical considerations: erenumab and fremanezumab are monthly subcutaneous injections, eptinezumab is a quarterly intravenous infusion. Cost, insurance coverage, and patient preference become the deciding factors rather than efficacy.
How the study worked
Systematic literature search of PubMed through December 2019 for phase II/III randomized clinical trials of CGRP-pathway monoclonal antibodies. Inclusion criteria required similar populations, follow-up lengths, and comparators (placebo). The primary efficacy endpoint was ≥50% reduction in migraine days per month. Chronic migraine was defined as ≥15 headache days/month with ≥8 migraine days (≥4 hours each). Adjusted indirect comparison used Bucher's method. Equivalence was assessed using a positioning guide with delta value calculated as half the absolute risk reduction from meta-analysis.
What this study cannot tell us
Indirect treatment comparisons are less reliable than head-to-head randomized trials. Only 3 of 30 identified trials met the strict inclusion criteria, limiting the analysis. Galcanezumab was identified in the search but no suitable trial met criteria for inclusion. The analysis was limited to one efficacy endpoint (≥50% migraine day reduction) and didn't assess other outcomes like total migraine day reduction or patient-reported outcomes. The search was conducted in 2019 and doesn't include more recent evidence.
How to read the evidence
This is an adjusted indirect treatment comparison — a recognized but inherently limited methodology compared to direct head-to-head trials. The use of strict inclusion criteria and a pre-defined equivalence margin adds rigor, but only 3 of 30 trials could be included.
When this study was published
Published in 2020 with a 2019 literature search, this was one of the earlier comparative analyses of CGRP antibodies. The equivalence conclusion has been generally supported by subsequent real-world evidence and more recent analyses.
The bigger picture
As the CGRP-targeting peptide antibody market matures, comparative effectiveness evidence becomes critical for health economic decisions and clinical guidelines. This study supports the view that these drugs represent variations on the same therapeutic mechanism rather than meaningfully different clinical options. As biosimilar versions of these antibodies eventually enter the market, this equivalence data will inform formulary substitution policies and potentially drive down costs for migraine patients.
Questions still open
- Would a head-to-head randomized trial confirm the therapeutic equivalence suggested by this indirect comparison?
- Do the drugs differ in durability of response or in specific migraine subtypes that this analysis couldn't detect?
- As more real-world data accumulates, will switching between CGRP antibodies prove clinically seamless as this equivalence suggests?
Common questions
Are all CGRP migraine drugs equally effective?
How should I choose between these migraine antibodies?
Read the original research
Monoclonal antibodies against calcitonin gene-related peptide in chronic migraine: an adjusted indirect treatment comparison.
Farmacia hospitalaria : organo oficial de expresion cientifica de la Sociedad Espanola de Farmacia Hospitalaria, 44(5), 212-217
Citation
Briceño-Casado, María Del Pilar; Gil-Sierra, Manuel David; Fénix-Caballero, Silvia. (2020). Monoclonal antibodies against calcitonin gene-related peptide in chronic migraine: an adjusted indirect treatment comparison.. Farmacia hospitalaria : organo oficial de expresion cientifica de la Sociedad Espanola de Farmacia Hospitalaria, 44(5), 212-217. https://doi.org/10.7399/fh.11419