A systematic review of economic evaluations of pharmacological treatments for adults with chronic migraine

Background and aims: Chronic migraine is a common neurovascular brain disorder with substantial economic costs. We performed a systematic review to identify economic evaluations of pharmacological treatments for adults with chronic migraine. Methods: We undertook systematic literature searches using terms for migraine/headache and prophylactic drug interventions, combined with economic/cost terms where appropriate. Using inclusion and exclusion criteria, two reviewers independently assessed the citations and abstracts, and full-text articles were retrieved. A review of study characteristics and methodological quality was assessed. Results: Sixteen citations met the inclusion criteria and were model-based cost-utility studies evaluating: Botox (n = 6); Erenumab (n = 8); Fremanezumab (n = 2); and Galcanezumab (n = 1) as the main treatment. They varied in their use of comparators, perspective, and model type. Botox was cost-effective compared to placebo with an incremental cost-effectiveness ratio (ICER) ranging between £15,028 (€17,720) and £16,598 (€19,572). Erenumab, Fremanezumab and Galcanezumab when compared to Botox, was associated with ICERs ranging between £59,712 ($81,080) and £182,128 (€218,870), with the ICERs above the most common willingness-to-pay thresholds (WTPs). But they were cost-effective within the commonly used WTPs among the population for whom the previous treatments including Botox were failed. Three studies compared the cost-effectiveness of Erenumab against the placebo and found that Erenumab was dominant. All studies performed sensitivity analyses to check the robustness of their results. None of the findings from the included articles were generalisable and none of the included studies fulfilled all the criteria mentioned in the CHEERS 2022 reporting checklist and Phillips’s checklist for economic models. Conclusions: Evidence to support the cost-effectiveness of pharmacological treatments of chronic migraine in the adult population using Botox and Erenumab were identified. Our findings suggest that both Botox and Erenumab, are cost-effective compared to placebo; although Erenumab had more incremental economic benefits compared to Botox, the ICERs were above the most common willingness-to-pay thresholds. Hence, Erenumab might be an acceptable treatment for chronic migraine for patients whom other treatments such as Botox do not work. Further research is needed to help characterise the data to adequately structure and parameterise an economic model to support decision-making for chronic migraine therapies.