It has taken more than two decades, since the introduction of triptans in the clinic, back in the 90s, for the symptomatic treatment of migraine, to have a new specific anti-migraine therapy, although now for preventive purposes. This is what has come to be called “the migraine vaccine” in the social networks, with some success, although in reality it is not, due to its similarities with other vaccines (preventive nature and subcutaneous administration).
Key to the new drugs for migraine treatment
Unlike the usual preventive treatments, based on “chemistry”, these new treatments are based on “biology”, in that they are monoclonal antibodies specifically developed to block a key molecule in the migraine crisis, the CGRP (Calcitonin Gene Related Peptide). In short, they represent a more specific approach to migraine than the currently available preventive drugs, none of them designed to combat migraine, but their beneficial action on this pathology was known after their introduction in clinic for the treatment of other pathologies (hypertension, epilepsy, depression, …).
These new anti-CGRP drugs were approved in 2018 by the Food and Drug Administration (FDA), the US agency responsible for authorizing new drugs and treatments. They subsequently received the green light from the European Medicines Agency and have been available in our country since last November 1, specifically two molecules, namely: Erenumab and Galcanezumab. It is foreseeable that another will be marketed in 2020.
In practical terms, both drugs are administered subcutaneously once a month. The choice of the drug, dosage and time to be maintained will be the competence of the neurologist responsible for the patient.
Migraine symptoms
Migraine is the primary headache par excellence and, as has been repeated ad nauseam, it is “more than just a headache”. Sufferers experience recurrent episodes (“crises”) in which they are afflicted by a whole constellation of symptoms that, not infrequently, entail the need for isolation and bed rest. Namely:
- Headache, generally of medium or high intensity, often of pulsatile quality and hemicranial distribution.
- Digestive symptomatology, expressed by “churning”, nausea or vomiting.
- Hypersensoriality, as the patient is bothered by environmental stimuli (lights, noises, smells, …).
- Intolerance to movement, which is why patients avoid jumping, running, … during crises.
- Irritability, as the main mood complaint.
What causes migraine?
It is well known that migraine has a strong genetic component. It is estimated that nine out of ten sufferers have close relatives with the same disorder. A series of “precipitating factors” (menstruation, stress, alcohol, lack/excess of sleep, certain foods, etc.) will then act on this “genetically migraine-prone brain” and trigger the actual attack.
The prevalence of migraine in Spain is around 12.6% of the adult population, according to data from the PALM Study, the largest study carried out in our country.
What type of patients will benefit from these new treatments?
The indication approved “in the technical file”, for both Erenumab and Galcenezumab, is to have a minimum of 4 migraine attacks per month, in short, the usual approach to date when considering the indication for preventive treatment. However, the economic conditioning factor of these new drugs, which are considerably more expensive than those currently in use, has led the Spanish health authorities to raise the bar and limit their coverage by the National Health System to those who suffer at least 8 attacks per month and, in addition, have previously failed at least 3 preventive drugs (to which botulinum toxin should be added in the case of patients with chronic migraine).
Another peculiarity of these drugs is that they will not be obtained from traditional pharmacies, but will be dispensed in hospital, after formal prescription by the neurology specialists responsible for the patient. In principle, it seems prudent to assess the response of patients after the first three doses. It is also the duty of prescribing neurologists to evaluate the safety/tolerability profile (in clinical trials it is quite good) in order to be aware of possible infrequent adverse effects not detected in the clinical trial phase.
In short, migraine patients are to be congratulated, especially those in whom the treatments currently in use have not achieved satisfactory control of their situation. In this sense, many people are confident that it will bring them an improvement in their quality of life.