One in seven Americans suffers from migraines, and medications currently prescribed to prevent them—like blood-pressure drugs and antidepressants—don’t work for many people. But two new studies offer hope for those who haven’t respond well to existing treatments. In late-stage clinical trials, a new type of drug reduced migraine frequency and severity by up to 50% in some people.
The two studies were published this week in the New England Journal of Medicine. One study tested the effectiveness of the drug erenumab, co-developed by Novartis and Amgen, in a trial of 955 people with migraines. The other study involved 1,130 people and tested the effectiveness of Teva Pharmaceutical’s fremanezumab. Both drugs have been submitted for approval by the Food and Drug Administration, and their manufacturers hope to introduce them to the market in 2018.
In the new 6-month erenumab study, 43% of people given a low-dose monthly injection of the drug—and 50% of patients given a high-dose monthly injection—reported that their migraine frequency and severity was reduced by about half. Only about 27% of people who received a placebo injection reported such improvement.
Before the study, people reported having migraines an average of eight days a month. That number was reduced by 3.2 days for people who got the low dose of the drug, and by 3.7 days for those who got the higher dose—but only by 1.8 days for those who got the placebo.
The fremanezumab study tested both a monthly and a quarterly drug injection against a placebo. After three months, 41% of those who’d received the drug once a month reported their headaches had been reduced by at least half, compared to just 18% of those who had received the placebo. In a third group, which received the drug injection just once over the three-month period, 38% of people reported this level of improvement.
Both groups that received at least one fremanezumab injection reported between four and five fewer headache days a month, out of an average of 13 days at the start of the study. People who received three placebo injections reported only 2.5 fewer headache days.
Erenumab and fremanezumab are monoclonal antibodies: lab-produced drugs that mimic immune cells in the body by binding to specific proteins. Both drugs target a substance called calcitonin gene-related peptide (CGRP), which is released by the body during migraines. Scientists aren’t sure how exactly CGRP influences migraine pain, but they suspect it alters blood-vessel activity and nerve sensations in the brain. By blocking this peptide, they hope to reduce or prevent migraine occurrences.
The new studies show that antibody therapies don’t work for everyone. But the fact that they were able to help a subset of people who hadn’t responded to other types of medications is a “big deal,” says Dr. Peter Goadsby, professor of neurology at University College London and co-author of the erenumab study.
It’s also a big deal, he says, that these medicines have been developed specifically to target a known migraine trigger. “It contrasts with what we have now, which are medicines that drifted into migraine from many other areas, such as blood pressure control, epilepsy and depression,” says Goadsby. “It has no other effects than to control migraine.” (Triptan medications are currently prescribed for the treatment of migraines that have already begun, but no drugs are specifically approved to prevent them before they start.)
An editorial published along with the studies notes that most of the improvements in both trials were evident after just one or two months. This suggests that doctors and patients will be able to decide quickly whether a new drug is working for them or not, wrote Dr. Andrew Hershey, director of neurology at Cincinnati Children’s Hospital Medical Center.
It’s also promising, Hershey wrote, that a number of people in both trials became completely headache free. The drugs appear to have few side effects; the most common complaint in both studies—in those who received the drug and the placebo—was pain and irritation at the injection site.
The manufacturers of erenumab hope to market their drug for the prevention of episodic migraines (fewer than 15 headache days a month), while fremanezumab will be indicated for the prevention of chronic migraines (15 or more headache days a month). Two other pharmaceutical companies are currently developing other CGRP-targeting antibody drugs, as well.
More research will be needed, the editorial states, to determine whether certain people with migraines respond differently to each of these drugs, or whether one works better than the others. It also cautions that these types of drugs are likely to be expensive when they do hit the market. “Many patients will probably still have a response to standard multidisciplinary treatment that is less costly in patient and provider time and dollars,” Hershey wrote.
Still, Hershey believes that a migraine-specific preventive treatment is an important advance for patients, calling CGRP the “next frontier” in migraine research. As doctors continue to learn about the mechanisms that cause these headaches in the first place, he wrote, “one may expect new compounds to bring a brighter future to our patients who have migraines.”