Post hoc analyses revealed patients with episodic migraine (EM) who take erenumab experience less intense headache pain on average.
Among individuals with episodic migraine (EM) and chronic migraine (CM), recently published research shows erenumab reduced cumulative monthly migraine pain and significantly reduced monthly average migraine pain in patients with EM. Findings of the post hoc analysis were published in Cephalalgia.
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.
Previous studies have confirmed the safety and efficacy of erenumab in preventing migraine and revealed the drug is effective in reducing monthly migraine days (MMD) in both EM and CM. However, “there is a need to evaluate additional treatment benefits (eg, reduction in pain intensity) that is not captured by these outcome measures alone,” the researchers wrote.
Assessment of pain intensity is also a recommended secondary end point in controlled clinical studies of migraine prevention treatment, they continued.
To better understand the effect of erenumab on migraine pain intensity, the investigators conducted a post hoc analysis of 2 pivotal randomized placebo-controlled studies of erenumab in patients with EM or CM.
The trial conducted among EM patients was carried out across 121 sites in North America, Europe, and Turkey, while the CM trial was conducted at 69 sites across North American and Europe. All individuals included were aged 18 to 65.
“The primary end point in each study was the change in mean MMD from baseline for the last 3 months (mean over months 4-6, EM study) or for the last month (month 3, CM study) of the DBTP [double-blind treatment phase],” the authors explained. Patients also reported peak pain intensity and date of migraine onset in daily headache diaries.
Cumulative monthly migraine pain intensity was defined as the sum of peak pain intensity scores (0 = no migraine to 3 = migraine day with severe pain) reported on migraine days. Efficacy analyses were conducted among 946 patients with EM and 656 patients with CM. The majority of patients included in each study was female, and migraineurs reported an approximate age of 21 when asked about migraine onset.
The researchers found:
“While baseline pain intensity was similar for EM and CM populations, in general, reductions in pain intensity were less pronounced for patients with CM compared to patients with EM,” authors said. “This difference could reflect the longer treatment period for patients with EM (6 months) vs patients with CM (3 months),” they hypothesized.
As an association between the degree in reduction of MMD and the degree in reduction in pain intensity on days patients reported breakthrough headaches was seen, the researchers noted these 2 benefits may share a common mechanism.
Overall, these findings suggest that patients with EM who receive erenumab may experience additional benefits beyond just reduction in MMD.
The small range of the 0-3 scale to assess pain intensity marks a limitation to this analysis, in addition to the fact researchers only collected peak pain intensity per headache episode for patients with EM and per headache day for those with CM.
“Future studies of migraine pain should consider use of a broader and more sensitive rating scale and analysis of the duration of time spent with moderate or severe pain to better assess the impact of treatment on migraine pain intensity,” the researchers concluded.
Lipton RB, Dodick DW, Kudrow D, et al. Reduction in migraine pain intensity in patients treated with erenumab: a post hoc analysis of two pivotal randomized studies. Cephalalgia. Published online August 18, 2021. doi:10.1177/03331024211028966