A Study to Evaluate the Efficacy and Safety of Erenumab in Adults With Medication Overuse Headache

Study 20170703 is a phase 4, randomized, double-blind, double-dummy, parallel-group, placebo-controlled study to evaluate the safety and efficacy of erenumab against placebo in a CM population with MOH and prior history of treatment failure. Participants will be enrolled based on fulfilment of the International Classification of Headache Disorders, 3rd Edition (ICHD-3) CM and MOH criteria and will not be advised to early discontinue acute medication. Participants who successfully complete the 24-week double-blind treatment period (DBTP) of the study will be offered an opportunity to continue in an open-label treatment period (OLTP) of 28-weeks duration. Participants who received erenumab treatment during the DBTP will continue to receive the same erenumab dose during the OLTP. Participants who received placebo during the DBTP will be allocated in a 1:1 ratio to receive either erenumab 70 mg or 140 mg SC QM during the OLTP. All participants will remain blinded to their original DBTP treatment assignment.