In an open-label extension spanning 5 years, the safety profile of erenumab was consistent with the double-blind treatment phase of the study, and there were no increases in adverse event rates.
Results from the 5-year, open-label treatment period of a phase 2 study in episodic migraine prevention showed that erenumab (Aimovig) helped patients achieve sustained reductions in both the number of monthly migraine days (MMD) and the number of days in which therapies were needed for acute migraines.
Amgen and Novartis released the results during the Migraine Trust Virtual Symposium. Erenumab, the first-of-its-kind calcitonin gene-related peptide (CGRP) inhibitor, was approved for sale in the United States and the European Union in 2018. Its safety profile was consistent with the double-blind treatment phase of the study, and there were no increases in adverse event rates over the 5 years.
The 5-year open label extension enrolled 383 patients with episodic migraine who had previously completed the 12-week, double-blind, placebo-controlled trial. Episodic migraine was defined as 4 to 14 migraine days and less than 15 headache days per month.
Results from the extension period were compared with the baseline seen in the double-blind portion. All patients initially received 70-mg erenumab monthly, with 250 patients increasing their dosage to 140 mg monthly.
Among the 216 patients who completed the open-label treatment phase, there was an average MMD reduction of 5.3 days from the baseline of 8.7 days.
By the end of the study, patients who had used acute migraine therapies to treat their migraines saw an average reduction in use of 4.4 days from a baseline of 6.2 days with erenumab.
The most common adverse effects were nasopharyngitis, upper respiratory tract infection, and influenza.
"These important data highlight the sustained efficacy, safety, and tolerability profile of Aimovig, and provide crucial information for patients and doctors managing migraine," said Messoud Ashina, MD, PhD, professor of neurology in the Faculty of Health and Medical Sciences at the University of Copenhagen. "The study reinforces the potential of Aimovig to reduce monthly migraine days over the long term for people living with this debilitating, yet underdiagnosed disease.”
"Aimovig continues to have the longest safety and efficacy trial data among treatments for migraine in the calcitonin gene-related peptide class of medications," said Darryl Sleep, MD, senior vice president, Global Medical, and chief medical officer at Amgen. "These long-term results further demonstrate the potential of Aimovig to help the millions of patients who may be candidates for preventive treatment."
The companies also released interim 2-year results of the open-label extension of the LIBERTY study, which involved patients with episodic migraine taking erenumab who failed 2 to 4 prior preventive treatments. As with the other results, there was sustained efficacy and no increases in adverse events rates.
The phase 3 EMPOwER study results, which highlighted the efficacy and safety of erenumab in adult patients with episodic migraine from Asia, the Middle East and Latin America, were also released.