Data Show Erenumab’s Efficacy, Safety in Episodic Migraine After 2 Years

Recently published results of the LIBERTY study on erenumab for episodic migraine (EM) revealed efficacy was sustained over 112 weeks in individuals with difficult-to-treat EM, for whom 2 to 4 previous migraine preventives have failed. Findings were published in the Journal of Neurology, Neurosurgery & Psychiatry and presented at the 62nd Annual Scientific Meeting of the American Headache Society.

Erenumab is a fully human monoclonal antibody, first approved in 2018, that is administered monthly via self-injection of a 70- or 140-mg dose. It works to block the calcitonin gene-related peptide (CGRP) receptor, which is believed to play a crucial role in the pathophysiology of migraine.

Adherence to current non-CGRP oral preventive medicines for migraine is poor, authors wrote, and these treatments do not yield improvements for many patients.

Prior LIBERTY results have demonstrated erenumab’s efficacy in patients with EM after 12 weeks. In the current study, researchers outlined findings from the 2-year efficacy, safety, and tolerability follow-up among 181 LIBERTY participants. All patients completed the double-blind treatment phase (DBTP) of the trial and entered an ongoing 3-year open label extension phase (OLEP).

Participants in Europe and Australia received 140-mg doses of erenumab monthly and were unable to receive other preventive comedications throughout the study window. Any individual who was 50 years or older at the age of migraine onset was excluded from the analysis.

In total, 181 of 240 randomized patients (75.4%) completed 112 weeks of the OLEP, while 24.6% discontinued, largely due to lack of efficacy, participant decision, and adverse events (AEs). In addition, “main outcomes assessed at week 112 were: ≥50%, ≥75% and 100% reduction in monthly migraine days (MMD) as group responder rate and individual responder rates, MMD change from baseline, safety, and tolerability,” authors wrote.

Analyses revealed the following:

• The ≥50% responder rate was 57.2% (99/173) at 112 weeks.
• Of ≥50% responders at the end of the DBTP, 36 of 52 (69.2%) remained responders at at least 50% of visits and 22 of 52 (42.3%) at more than 80% of visits.
• Of the nonresponders at the end of the DBTP, 60 of 185 (32.4%) converted to ≥50% responders in at least half the visits and 24 of 185 (13.0%) converted to ≥50% responders in more than 80% of visits.
• Change from baseline at 112 weeks in mean (SD) MMD was −4.2 (5) days.
• Common AEs (≥10%) were nasopharyngitis, influenza, and back pain.
• A higher and consistent improvement was observed in the change from baseline in MMDs and functional outcomes in participants who switched to erenumab at week 12 compared with those who continued erenumab.

Researchers found that the rate of serious AEs remained stable over 2 years and rates of treatment discontinuation due to AEs were low. Constipation was also reported in 8 participants continuing erenumab in the OLEP and in 5 participants who switched to erenumab, they added. Overall “no deaths were reported, and no new safety findings were reported in participants during the 2-year OLEP.”

Findings are in accordance with erenumab’s safety profile reported in other long-term studies. However, these were carried out in populations not specifically selected due to their failure to prior migraine preventives.

Responder bias may have been present in this study, marking a limitation, and the “numerical rise in individual responder rates may be due to missing values among non-responders that prematurely discontinued the study,” researchers wrote. The sample size in this study was also relatively small and only included those with EM.

“Erenumab is a novel, effective and safe preventive treatment option for difficult-to-treat migraine,” they concluded.

Reference

Ferrari MD, Reuter U, Goadsby PJ, et al. Two-year efficacy and safety of erenumab in participants with episodic migraine and 2–4 prior preventive treatment failures: results from the LIBERTY study. J Neurol Neurosurg Psychiatry. Published online November 29, 2021. doi: 10.1136/jnnp-2021-327480