Response to erenumab assessed by Headache Impact Test-6 is modulated by genetic factors and arterial hypertension: An explorative cohort study

Background and purpose: Response predictors to erenumab (ERE) in migraine patients would benefit their clinical management. We investigate associations between patients' clinical characteristics and polymorphisms at calcitonin receptor-like receptor (CALCRL) and receptor activity-modifying protein 1 (RAMP1) genes and response to ERE treatment measured as clinically meaningful improvement on the Headache Impact Test-6 (HIT-6) score. Methods: This post hoc analysis of a prospective, multicenter, investigator-initiated study involves 110 migraine patients starting ERE 70 mg/month. Demographics, medical history, and migraine-related burden measured by HIT-6 score were collected during 3 months before and after ERE start. Selected polymorphic variants of CALCRL and RAMP1 genes were determined using real-time polymerase chain reaction. Logistic regression models identified independent predictors for response to ERE, defined as HIT-6 score improvement ≥ 8 points (HIT-6 responders [HIT-6 RESP] vs. HIT-6 nonresponders). Results: At Month 3, 58 (52.7%) patients were HIT-6 RESP. Comorbid hypertension predicted a lower probability of being HIT-6 RESP (odds ratio [OR] = 0.160, 95% confidence interval [CI] = 0.047–0.548, p = 0.003). Compared to major alleles, minor alleles CALCRL rs6710852G and RAMP rs6431564G conferred an increased probability of being HIT-6 RESP (for each G allele: OR = 2.82, 95% CI = 1.03–7.73, p = 0.043; OR = 2.10, 95% CI = 1.05–4.22, p = 0.037). RAMP1 rs13386048A and RAMP1 rs12465864G decreased this probability (for each rs13386048A, OR = 0.53, 95% CI = 0.28–0.98, p = 0.042; for each rs12465864G, OR = 0.32, 95% CI = 0.13–0.75, p = 0.009). A genetic risk score based on the presence and number of identified risk alleles was independently associated with HIT-6 RESP (OR = 0.49, 95% CI = 0.33–0.72, p = 0.0003), surviving Bonferroni correction. Conclusions: Response to ERE was associated with comorbid hypertension and specific allelic variants in CALCRL and RAMP1 genes. Results require confirmation in future studies.