Psychological predictors of negative treatment outcome with Erenumab in chronic migraine: data from an open label long-term prospective study.

BACKGROUND Monoclonal antibodies (mABs) targeting the calcitonin gene-related peptide (CGRP) pathway represent the first disease-specific preventive migraine therapy. Growing evidence suggests that they are effective in the preventive treatment of difficult-to-treat patients. In this study, we evaluated the psychological predictors of the outcome of treatment with the anti-CGRP monoclonal antibody erenumab in patients with chronic migraine (CM). METHODS Seventy-five patients with CM who had already failed at least 3 preventive therapies received erenumab every 28 days for a period of 12 months. Before the first administration, patients received a full psychological evaluation using The Structured Clinical Interview for DSM-5 Clinician Version (SCID-5-CV) to assess personality disturbances (primary outcome), mood and anxiety disorders, and as well specific questionnaires to evaluate alexithymia traits, childhood traumas, and current stressors (secondary outcomes). RESULTS After 12 months of treatment, 53 patients reported a reduction of at least 50% in headache days/per month (Responders), whereas 22 did not (Non Responders). When compared to Responders, Non Responders were characterized by a higher prevalence of personality disorders belonging to Cluster C (avoidant, dependent, and obsessive-compulsive) (77% vs 37%, p = .001). Non Responders were also characterized by a higher prevalence of anxiety disorders (90% vs 60%, p = 0.007), showed more alexithymic traits (51.7 ± 13.7 vs 42.9 ± 14.3, p = 0.017), and reported a higher number of 'at least serious' current stressors (3.2 ± 4.0 vs 0.8 ± 1.4, p < .0001) than Responders. At the multivariate analysis, higher prevalence of Cluster C personality disorders (OR 3.697; p = 0.05) and higher number of 'at least serious' life events (OR 1.382; p = 0.017) arose as prognostic factors of erenumab failure. CONCLUSIONS Erenumab confirmed its effectiveness in a population of difficult-to-treat migraine. The presence of "anxious-fearful" personality together with current stressors and anxiety represent negative predictors of treatment outcome. TRIAL REGISTRATION The study protocol was registered at clinicaltrials.gov ( NCT04361721 ).