Study leader Dr. Peter Goadsby, from King's College Hospital in the United Kingdom, and colleagues have revealed that the drug led to "significant and meaningful" benefits for people with episodic migraine over the course of 6 months, with around half of them seeing their number of migraine days fall by at least 50 percent.
The researchers recently reported the findings of their phase III clinical trial in the New England Journal of Medicine.
Migraine is one of the most common and debilitating conditions in the United States, affecting around 12 percent of children and adults in the country.
More than just a "bad headache," migraine is characterized by a severe throbbing pain on one or both sides of the head. And, in some cases, head pain may be accompanied by other symptoms, including nausea, vomiting, numbness or tingling in the face or extremities, sensitivity to light and sound, and vision problems.
Migraine attacks normally last for anywhere between 4 and 72 hours. People who have up to 14 migraine days each month are considered to have episodic migraine, while 15 or more migraine days per month constitute chronic migraine.
There is no one-size-fits-all approach to treating migraine, and prevention and management of migraine attacks may involve a combination of off-label medications and non-drug approaches. Finding an effective treatment strategy involves trial and error.
Because the precise causes of migraine remain unclear, the development of new treatments for the condition is hugely challenging. The new study, however, may bring us one step closer to the approval of a drug designed specifically for the prevention of migraine: erenumab.
Erenumab and episodic migraine
Previous research has indicated that the activation of calcitonin gene-related peptide (CGRP) — a neuropeptide expressed in the peripheral and central nervous system — plays a significant role in the development of migraine.
Erenumab — developed by pharmaceutical company Novartis, who part-funded the study — is a monoclonal antibody that blocks the CGRP receptor.
Dr. Goadsby and his team of researchers tested erenumab in a phase III, randomized, double-blind, placebo-controlled clinical trial, called the Study to Evaluate the Efficacy and Safety of AMG 334 in Migraine Prevention (STRIVE).
The researchers enrolled a total of 955 individuals with episodic migraine.
Participants were randomly assigned to one of three groups for 6 months: 317 subjects received 70 milligrams of erenumab once per month, 319 received 140 milligrams of erenumab once per month, and the remaining 319 subjects received a placebo. Erenumab was administered via a subcutaneous injection.
At study baseline, participants experienced an average of 8.3 migraine days per month. The team assessed how erenumab treatment affected the number of monthly migraine days at 4, 5, and 6 months after the first injection.
Migraine days halved for some patients
The study was completed by 90 percent of the participants, and the primary endpoint for the study was the "change in mean monthly migraine days from baseline over the last 3 months of the double-blind treatment phase of the study (months 4, 5, and 6)."
Overall, the researchers found that participants who received the 140-milligram dose of erenumab experienced a 3.7-day reduction in the number of migraine days, while those who took the 70-milligram dose saw their number of migraine days fall by 3.2 days.
In comparison, subjects who received the placebo only saw a 1.8-day reduction in their number of migraine days over 6 months.
Looking at the results on an individual basis, the researchers found that 43.3 percent of those who took the 70-milligram dose of erenumab saw their number of monthly migraine days more than halved, and this was also the case for 50 percent of subjects who took the 140-milligram dose.
Just 26.6 percent of participants who took the placebo experienced a 50 percent or greater reduction in the number of monthly migraine days, the team reports.
A 'real transition for migraine patients'
Additionally, the team found that those who received either dose of erenumab showed significant improvements in physical impairments caused by migraine, as determined by their scores on the physical-impairment and everyday-activities fields of the Migraine Physical Function Impact Diary.
Erenumab-treated subjects also reported a reduction in the use of acute migraine medication over the 6-month study period.
Dr. Goadsby says that the study results "clearly show" that blocking the CGRP pathway is a feasible strategy for preventing migraine attacks and reducing their severity.
"The results of STRIVE represent a real transition for migraine patients from poorly understood, repurposed treatments, to a specific migraine-designed therapy. STRIVE, as with the monoclonal antibody developments generally, represents an incredibly important step forward for migraine understanding and migraine treatment."
Dr. Peter Goadsby
The researchers conclude that erenumab's durability and long-term safety should be assessed in future studies, but they are hopeful that the drug could offer an effective treatment for people with migraine.
"People with migraine are missing out due to this debilitating neurological disease and are in need of safe, tolerable, and effective preventive treatments," notes Vas Narasimhan, chief medical officer for Novartis. "We are committed to bringing this much-needed treatment option to patients as soon as possible."