Anti-CGRP monoclonal antibodies demonstrate sustained long-term effectiveness and safety for chronic migraine over 4 years
Background
Current guidelines for migraine management recommend discontinuing anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies after 12-18 months due to limited long-term safety and efficacy data. While these antibodies are known to be effective, the optimal treatment duration and sustained safety beyond this period have remained uncertain. This knowledge gap necessitates large-scale, real-world evidence to inform clinical practice, particularly for patients with chronic, resistant migraine who benefit from targeting the CGRP pathway.
Study Design
This multicenter retrospective study analyzed 454 patients from 13 headache units who received the same anti-CGRP antibody for at least 24 months. The treatments included erenumab (39%), galcanezumab (34%), and fremanezumab (27%). Baseline characteristics, monthly headache days (MHD), monthly migraine days (MMD), and adverse events (AEs) were recorded at baseline, 6 months, 1, 2, 3, and 4 years. Descriptive statistics summarized clinical features, while parametric or non-parametric tests were used for group comparisons. Multivariate analyses explored associations between baseline variables and long-term treatment response.
Results
A total of 454 patients were analyzed, with follow-up data available for 454 at 2 years, 135 at 3 years, and 17 at 4 years. Sustained and significant reductions in migraine frequency were observed:
Monthly headache days (MHD) decreased from 20 at baseline to 6 at 2 years, 6 at 3 years, and 5 at 4 years. Monthly migraine days (MMD) similarly dropped from 14 at baseline to 4 at 2 years, 4 at 3 years, and 2 at 4 years. Medication overuse also substantially decreased from 78% at baseline to 13% at 2 years, 20% at 3 years, and 18% at 4 years. Loss of effectiveness was reported in only 4.2% of patients after 2 years. Adverse events occurred in less than 20% of patients, with over 80% being mild, leading to discontinuation in a mere 0.4%. Multivariate analysis revealed that shorter disease duration prior to anti-CGRP initiation, earlier anti-CGRP initiation, and greater MHD/MMD reduction at 6 months were associated with better long-term outcomes.
Key Findings
- Monthly headache days (MHD) decreased from 20 to 6 at 2 years, 6 at 3 years, and 5 at 4 years.
- Monthly migraine days (MMD) decreased from 14 to 4 at 2 years, 4 at 3 years, and 2 at 4 years.
- Medication overuse decreased from 78% at baseline to 13% at 2 years.
- Adverse events occurred in <20% of patients, with 0.4% discontinuing due to AEs.
- Shorter disease duration and earlier anti-CGRP initiation predicted better long-term outcomes.
Why It Matters
This study provides crucial real-world evidence supporting the long-term use of anti-CGRP monoclonal antibodies, challenging the current guideline-recommended discontinuation after 12-18 months. Patients can safely and effectively continue anti-CGRP mAb therapy beyond 2 years, potentially for up to 4 years, with sustained benefits and a low incidence of adverse events. This finding has significant implications for clinical practice, suggesting that clinicians may extend treatment duration for responders without undue safety concerns. For individuals managing chronic migraine, this means a more stable and potentially longer-lasting therapeutic option, reducing the need for treatment cycling and improving quality of life. The identified predictors of long-term success also offer insights for optimizing patient selection and timing of initiation.
anti-cgrp
monoclonal-antibody
migraine
chronic-migraine
erenumab
galcanezumab