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).