A Functional MRI Study on Erenumab Treatment Effects in Episodic Migraine Patients

This is a randomized, double blind, placebo-controlled trial with a 2-sequence, 2-period, 2-treatment crossover design. The study population will consist of adult male and female subjects with a documented history of episodic migraine (4 to 14 baseline migraine days), who have failed at least 2 previous migraine prophylactic treatment for lack of efficacy or tolerability. After a run-in phase of 4 weeks, patients will be randomized, according to a 1:1 ratio, to a 24 weeks of treatment, as follow: * Sequence 1: A/B * Sequence 2: B/A where: A=monthly subcutaneous erenumab 140 mg for 12 weeks; B=monthly subcutaneous masked placebo for 12 weeks