Anti-cgrp Monoclonal Antibodies in Chronic Migraine Prophilaxys: Efficacy and Safety in Patients Treated With Botulinum Toxin a

Abstract Since the high burden of chronic migraine (CM), it is challenging to identify the best prevention treatment. Based on the preclinical evidences about the different therapeutic targets of OnabotulinumtoxinA (BT-A), acting on C-fibers and anti-CGRP monoclonal antibodies (mAbs) acting on Aδ-fibers, the rationale of using as alternative or combining therapies has been hypothesized. Until now, the association of BT-A and mAbs has been poorly investigated. This study aimed to evaluate whether mAbs is effective and safe in CM patients previously treated with BT-A, either as alternative or add-on treatment. We enrolled 47 patients: according to the response to BT-A treatment, patients were defined Non-responder (NR) and Partial-responder (PR). NR were shifted to mAbs. PR were randomly divided into those who added mAbs therapy (PR-P) and those who shifted treatment (PR-S), interrupting BT-A. Clinical variables were collected at baseline, after three and six months. Study results evidenced the efficacy of mAbs in improving clinical outcomes in CM patients, with a better response in PR group. No statistically significant differences of clinical changes were observed between PR-P and PR-S groups. No safety concerns were raised in combined treatments. Preventive prophylaxis with mAbs is effective, even in difficult to treat CM patients. Further studies, with a larger sample size, are needed to highlight a potential additive effect of combined therapies.