Erenumab fares well in reducing migraine frequency
The human monoclonal antibody erenumab was safe and effective in reducing the number of migraine days in patients with migraine, according to studies presented at AAN 2019.
In the 12-week double-blind treatment phase (DBTP), 660 patients (mean age 42.5 years, 83.6 percent female) with chronic migraine (CM)* received placebo or once-monthly subcutaneous erenumab 70 or 140 mg. DBTP completers (n=609) who did not discontinue treatment may enter the 52-week open-label treatment phase (OLTP). Of these, 350 patients initially received once-monthly erenumab 70 mg while 60 patients were given erenumab 140 mg. Subsequent protocol amendment compelled 199 erenumab 70-mg recipients to graduate to 140 mg between weeks 4 and 28, while those who had completed the week 28 visit remained on the 70-mg erenumab dose. A total of 469 participants (n=266 and 203 for 70 and 140 mg, respectively) completed the OLTP. [AAN 2019, abstract P1.10-016]
At DBTP baseline, mean monthly migraine days (MMD) were 18.1 days and migraine-specific medication days (MSMD) were 9.5 days.
At week 52, mean change in MMD in the OLTP cohort was -9.3 days (-8.5 and -10.5 days for the 70- and 140-mg dose, respectively). For the acute MSMD, mean change from baseline was -6.4 days (-6.2 and -6.7 days, respectively).
In terms of mean MMD responder rates at week 52, more than half (59 percent) of OLTP participants achieved a ≥50 reduction in MMD. Based on the last dose received, 53 and 67 percent of the respective erenumab 70- and 140-mg recipients achieved a ≥50 reduction in MMD, reflecting the sustained efficacy of erenumab at 1 year.
Majority of the adverse events (AEs) were grade 1/2 in severity, with no grade 4 nor fatal AEs reported. There was a 26-percent discontinuation rate primarily due to consent withdrawal.
Similar safety and efficacy patterns were observed in a subanalysis of the STRIVE** study, which evaluated 955 individuals with episodic migraine (EM) who have failed prior preventive therapies. Participants were randomized 1:1:1 to receive monthly erenumab 70 or 140 mg or placebo during the 24-week DBTP. At week 24, 845 were rerandomized 1:1 to receive erenumab 70 or 140 mg for the following 28-week, dose-blinded active treatment phase. Of these, 41 percent had failed ≥1 preventive therapy. Baseline MMD and MSMD were 8.7 and 4.9 days, respectively. [AAN 2019, abstract P1.10-020]
At week 52, mean MMD changes were -3.4 and -4.2 days for the 70- and 140-mg erenumab arms, respectively, while for MSMD, mean changes were -1.9 and -2.5 days, respectively. More than half of erenumab 70- and 140-mg recipients achieved ≥50 percent reduction in MMD (52.3 percent and 55.0 percent, respectively).
Grade 3 AE and discontinuation rates were similarly low, with no grade 4 AEs reported.
The high level of response achieved by a substantial proportion of patients with EM – which represents a previously unmet need – with erenumab addresses the issue of low adherence to migraine prevention agents due to AEs, tolerability, or insufficient efficacy. [J Manag Care Pharm 2014;20:22-33; Headache 2013;53:644-655; Headache 2016;56:1635-1648]
Taken together, these findings show that 1 year of erenumab use was safe and well-tolerated among patients with CM and EM with sustained efficacy, noted the researchers of both trials.