Long-term persistence of anti-calcitonin gene-related peptide monoclonal antibodies in treatment-resistant migraine: A three-year follow-up study in Spain

Background and objective Migraine remains a therapeutic challenge, particularly in patients unresponsive to standard treatments. Although anti-calcitonin gene-related peptide (anti-CGRP) monoclonal antibodies (mAbs) represent a novel therapeutic option, long-term persistence data remain limited. This study aimed to evaluate three-year persistence with anti-CGRP mAbs in patients with treatment-resistant migraine. Secondary objectives included assessing treatment retention with the initial mAb and reasons for discontinuation. Methods This retrospective observational real-world study included adults with chronic or episodic migraine who initiated therapy between February 2020 and May 2021 at a tertiary hospital. Treatment persistence, switching, and reasons for discontinuation were analyzed. Binary logistic regression analysis was performed. Results Among 100 patients (81% women; mean age 51.8 years), 88% had chronic migraine. After three years, 37% remained on their initial mAb (molecule-specific persistence), while another 29% continued treatment after switching to a different mAb, yielding a total class-specific persistence rate of 66%. Discontinuation was due to lack of efficacy (12%), side effects (5%), no recurrence after treatment pause (4%), and unknown causes (13%). A temporary discontinuation after 12–18 months was associated with long-term molecule-specific and class-specific persistence ( p = 0.009 and p = 0.002, respectively). Conclusions Anti-CGRP mAbs show favorable long-term persistence in resistant migraine. Switching and temporary discontinuation strategies may enhance adherence and optimize outcomes.