I suffer from migraines. At least once a month, I have excruciating head pain, sensory problems and intermittent bouts of vomiting. The attacks can last for two weeks or more. Migraines have a huge impact on every aspect of my life, so it is with excited anticipation that I await the US Food and Drug Administration’s decision on a new drug that could prevent these attacks. The FDA’s decision is expected in the first half of 2018.
Although migraines affect about 15% of the world’s population – more than diabetes, epilepsy and asthma combined – advances in treatment have been sluggish, to say the least. The last occurred 30 years ago with the development of triptans.
During a migraine, blood vessels in the brain expand and press on nerve endings, causing pain. Triptans were developed to constrict blood vessels and so relieve pain. However, this treatment had mixed results with complete relief in some patients and minimal effects in others.
Personally, I have found triptans to help by slightly reducing symptoms during a migraine, but the attacks still happen. Triptans weren’t developed to prevent migraines, only to reduce the symptoms.
Some drugs that are used to reduce seizures in people with epilepsy, such as topiramate and valproate, have been used as preventative treatments for migraine, but they don’t work for everyone and often have a number of side effects. Having tried some of these drugs myself, I can report that the side effects are quite debilitating.
Migraine sufferers show what it feels like to have an attack.
A new class of drugs – calcitonin gene-related peptide inhibitors – has recently been developed that may change this. Calcitonin gene-related peptide (CGRP) is a neurotransmitter produced by neurons in the brain. As well as controlling blood flow, studies have shown CGRP levels increase during migraine attacks and slightly lower after treatment with triptans, which gives some relief from symptoms.
Human studies also show that people who suffer from migraines are more sensitive to CGRP levels, and high CGRP triggers migraine-like headaches within hours. This prompted the investigation of blocking CGRP as a new migraine therapy.
Monoclonal antibodies – a new type of large molecule drug – that target CGRP or its receptor are the first treatment for migraine to be developed in decades and the first ever for preventing migraine attacks. Results published in the New England Journal of Medicine from large late-stage clinical trials have shown that monthly injections of a drug called erenumab blocks CGRP binding to its receptor which reduced the occurrence of attacks in up to 60% of people. As a bonus, it had hardly any side effects.