For years researchers have tried to find ways to block various chemicals (neurotransmitters) released during a migraine attack, including serotonin, CGRP, nitric oxide, substance P, glutamate, and other. Triptans (such as IMitrex or sumatriptan), the first “designer” drugs for migraine, which were developed over 20 years ago, bind to a very specific subtype of serotonin receptor and are very effective in stopping a migraine attack.
A very promising new type of migraine medications is being developed by at least four different companies – Alder, Amgen, Eli Lily, and Teva. These drugs are monoclonal antibodies against the CGRP molecule or the CGRP receptor. CGRP (calcitonin gene-related peptide) is widely distributed in the body and is involved in regulating blood vessel opening and in the function of the nervous system. All four companies developing these drugs recently presented the results of their phase II clinical trials and the data looks very promising. The antibody tightly binds to its target (CGRP molecule or receptor) with the effect lasting a month, or in case of the Alder drug, up to 6 months. The Alder drug is given every six months intravenously, while the other three, are given every month by an injection into the muscle.
All four drugs appear to be very effective in preventing migraine attacks when compared to a placebo injection. And fortunately, at least so far, they all look very safe. However, in phase II trials only a couple of hundred patients are treated and we need to await the results of the larger and more definitive phase III trials to confirm the safety and efficacy of this new group of medications. This means that the earliest we will see these drugs approved by the FDA is in about 3 years.
It is possible that these drugs will be effective not only for the prevention of migraines, but also for stopping an acute migraine attack.
