Evaluating Fremanezumab for Chronic Migraine Prevention

Understanding the Mechanism of Action

In a recent multinational clinical trial, researchers assessed the effectiveness of two different fremanezumab regimens aimed at preventing chronic migraines. The transmission of pain signals during migraines is partly facilitated by the release of calcitonin gene-related peptide (CGRP) from one nerve and its reception by the next. Previous studies indicated that fremanezumab, an antibody therapy that targets CGRP and inhibits its reception, can decrease the number of days chronic migraine sufferers experience migraines and headaches. To establish the utility of fremanezumab as a preventive treatment for chronic migraine, it is essential to test its safety and efficacy across various regimens.

Trial Overview

A study published in the New England Journal of Medicine explored the safety and effectiveness of fremanezumab for chronic migraine prevention. The trial recruited otherwise healthy participants aged 18-70 from nine different countries who had been experiencing migraines for at least the past 12 months. Exclusion criteria included individuals who had persistent headaches for fewer than 15 days per month or migraine headaches for fewer than eight days per month, those who had recently received other migraine treatments, or those who used opioids or barbiturates at least four times in the last month.

Study Design and Patient Allocation

Participants were randomly assigned to one of three treatment regimens. The Fremanezumab + Placebo group received an initial dose of 675 mg of fremanezumab, followed by 1.5 mL placebo injections at weeks 4 and 8. The Fremanezumab only group received the same initial dose of 675 mg, followed by 225 mg at weeks 4 and 8. The Placebo group received 4.5 mL of placebo at the start and 1.5 mL at weeks 4 and 8. Throughout the study, patients documented the severity, duration, and frequency of their headaches and migraine symptoms.

Patient Demographics and Baseline Data

In total, 1,130 patients participated in the trial: 376 in the Fremanezumab + Placebo group, 379 in the Fremanezumab group, and 375 in the Placebo group. The average number of headache days at the trial’s onset was 13.2 for the Fremanezumab + Placebo group, 12.8 for the Fremanezumab group, and 13.3 for the Placebo group. Over the 12-week period, the average number of headache days was recorded as 8.5, 8.0, and 10.4 for the respective groups.

Effectiveness of Fremanezumab

The trial results indicated a significant reduction in headache days over the 12-week period: 4.3 days in the Fremanezumab + Placebo group, 4.6 days in the Fremanezumab group, and 2.5 days in the Placebo group. Monthly, 38%, 41%, and 18% of participants experienced a reduction of 50% or more in headache days, with average reductions of 4.9, 5.0, and 3.2 days, respectively. Additionally, headache-related disability decreased by 6.4 points, 6.8 points, and 4.5 points (on a 42-point scale) following week 8.

Adverse Events Observed

Mild to moderate adverse events were reported in 70% of the Fremanezumab + Placebo patients, 71% of those in the Fremanezumab group, and 60% of the placebo patients. The most common adverse effects included pain, skin thickening and hardening, and redness at the injection site. Liver dysfunction was noted in eight patients (0.8%), three of whom were in the Placebo group.

Conclusions and Future Research Directions

These findings suggest that fremanezumab may serve as an effective preventative therapy for chronic migraines. Both regimens tested demonstrated similar efficacy in reducing the average number of headache days and headache severity. Although adverse events were prevalent, most were mild to moderate and may be linked to the injection method.

As the study’s population was otherwise healthy, future investigations should examine the efficacy of fremanezumab in individuals with conditions that may influence migraine risk, such as obesity or specific infections. To fully understand the long-term safety and efficacy of fremanezumab, larger trials with extended follow-up periods are warranted.

Written by Raishard Haynes, MBS
Reference: Silberstein, S.D. et al. (2017). Fremanezumab for the Preventive Treatment of Chronic Migraine. N Engl J Med 2017; 377:2113-22. DOI: 10.1056/NEJMoa1709038