Migraine affects 12 to 15 per cent of Canadians, said Dr. Elizabeth Leroux, a Montreal-based neurologist, president of the Canadian Headache Society and chair of Migraine Canada, during a webinar hosted by Benefits Canada and sponsored by Lundbeck Canada Inc. in October.
According to the World Health Organization, a severe migraine attack is as disabling as quadriplegia, schizophrenia or dementia and migraine is the most prevalent neurological disorder, the second leading cause of global disability and the third most prevalent medical illness.
Migraine is different than a normal tension headache because of multiple other symptoms, such as sensitivity to lights, sounds, smells and movement, as well as nausea, difficulty eating or severe vomiting. Some migraines are accompanied by aura and potentially dizziness, brain fog or neck, sinus or facial pain.
Most people with migraine don’t have frequent attacks. However, frequent episodic migraine (8-14 days per month) and chronic migraine (more than 15 days per month) often require specialized medical care and treatment.
In addition, migraine has a significant impact on workplace absenteeism and presenteeism. It’s the second most frequently identified cause of short-term absence for non-manual employees and the third leading cause of presenteeism after allergies and hypertension.
Migraine is a chronic disease, noted Leroux, that’s treated with lifestyle recommendations and education, treatment for attacks and preventive therapy to decrease the frequency and intensity of attacks.
Until recently, migraine treatments were medications designed to treat other conditions. Unfortunately, they only provide a partial benefit, unpredictable response, serious side-effects and outcomes that may wear off over time, she said. “As a result, after a year, more than three-quarters of patients will stop treatment.”
There have been several new treatments for migraine in recent years, which “have changed the way we treat chronic migraine,” said Leroux. Still, despite these innovations, some chronic migraine patients aren’t doing well on any treatments and may remain disabled.
A new drug class, CGRP antibodies, is the first class of drugs designed to treat migraine based on scientific knowledge, noted Leroux. CGRP is a protein that plays an important role in migraine. Seventy-five per cent of the time, CGRP levels are elevated in people with migraine and correlate with the severity. Blocking this protein can decrease migraine frequency and intensity.
Although the average response rate to CGRP antibodies is 40 per cent, some people are super responders and have a 75 per cent or better response rate, which, said Leroux, “can make a massive difference in a person’s life.”
CGRP antibodies are better tolerated than oral medications and offer an alternative for patients who have tried other treatments without success. “We have never seen responses like this,” she said. “This is really a scientific breakthrough and we’re very enthusiastic about it.”
While employers offer workplace programs to support employees with migraine, Leroux noted she’s surprised some plans don’t cover any of the CGRP antibodies. “They should be covered because these employees can benefit significantly.”
Although CGRP medications all have the same target, she said patients may only have a 20 to 50 per cent chance of responding to one and will potentially need to try another. “Having four CGRP antibodies on the market provides options for patients and increases the chance of success.”
Leroux urged payers to develop reasonable coverage criteria and be flexible about how they evaluate patient response, noting some payers assess patient outcomes after initial approval to determine if treatment is working.
“Ideally, we would like a 100 per cent response rate, but a 50 per cent response rate is significant. Some patients will get a 75 per cent response, but please do not discard a 30 per cent response because this can make a massive difference.”
For example, if a patient has 16 migraine days per month, a 30 per cent response rate is five or six days gained. Some patients may respond with less intense attacks rather than reduced frequency, she noted.
Leroux also recommended a six-month trial period because response rates can vary significantly. When payers renew coverage, if the patient is doing better, they may not meet the initial prior authorization criteria and coverage will be terminated. “If it works, please authorize long term,” she urged payers, because “if you stop treatment, the migraines are just going to come back.”