Erenumab Efficacy on Comorbid Cluster Headache in Patients With Migraine: A Real-World Case Series.

BACKGROUND: Monoclonal antibodies (mABs) against calcitonin gene-related peptide (CGRP) or its receptor have emerged as effective and well-tolerated preventive medications for migraine. The key role played by CGRP has been recently demonstrated also in the pathophysiology of cluster headache (CH), paving the way for studies aimed to investigate the effectiveness of mABs targeting CGRP also in CH. However, no trials have been conducted so far to test the efficacy and tolerability of erenumab as CH preventive treatment. CASE SERIES: We describe the cases of 5 patients with both migraines and CH with previous failures of preventive treatments. All patients were treated with monthly erenumab (70 or 140 mg) showing good results not only on migraine but also on CH attacks frequency and intensity. Improvements of both intensity and frequency of CH attacks occurred only after at least 3 months of treatment, with monthly erenumab 140 mg, suggesting that longer treatment and higher doses are needed in CH in comparison to migraine. DISCUSSION AND CONCLUSION: Our findings support the efficacy and tolerability of monthly erenumab 140 mg as a preventive treatment in patients suffering from both migraines without aura and CH. We speculate that erenumab could represent a low-risk alternative for CH patients (with or without comorbid migraine) who did not tolerate common CH preventatives therapies or for whom the therapies were not successful. Certainly, randomized trials are needed to confirm these observations and we hope that our data, showing a delayed therapeutic effect only with the highest dose of erenumab (140 mg/month), can be taken into account in designing future trials.