Currently, there are several anti-CGRP treatments undergoing clinical trials. Some of these treatments involve monoclonal antibodies, which reduce the activity of CGRP, potentially leading to fewer migraine attacks. One of these anti-CGRP monoclonal antibodies, erenumab (Aimovig™), has been approved by the Federal Drug Administration (FDA) and is now available for patients. A second agent, fremanezumab (Ajovy™), was approved in September 2018. A week later, the FDA approved galcanezumab (Emgality™), making it the third anti-CGRP treatment currently on the market. Results from the clinical trials involving anti-CGRP antibodies have shown that about 50 percent of patients will have at least a 50 percent reduction in migraine days. “If you think about someone who has 20 migraine days per month, they have a 50 percent chance of having 10 or less migraine days,” Dr. Starling says. “We think that there are even these super-responders who have a 75 percent response rate, as well as super-super-responders who actually go into remission.” The results from these clinical trials are very promising, Dr. Starling adds. “The adverse events have been very minimal and the efficacy has been very good. It’s all looking up.” Dr. Starling says that although these medications are available, what really needs to be looked at is how to make them truly accessible for patients. Erenumab can cost about $7,000 per year without insurance coverage. “Insurance coverage is very, very key for the majority of our patient population,” she says. “Because the medications just came out on the market, there are still a lot of unknowns about insurance coverage.”
Botulinum toxin has been investigated for use in patients with blepharospasm in several studies. In an open label, historical ly controlled study, 27 patients with essential blepharospasm were injected with 2 Units of BOTOX at each of six sites on each side. Twenty-five of the 27 patients treated with botulinum toxin reported improvement within 48 hours. One patient was controlled with a higher dosage at 13 weeks post initial injection and one patient reported mild improvement but remained functionally impaired.
Ophthalmologists specializing in eye muscle disorders (strabismus) had developed the method of EMG-guided injection (using the electromyogram, the electrical signal from an activated muscle, to guide injection) of local anesthetics as a diagnostic technique for evaluating an individual muscle’s contribution to an eye movement. Because strabismus surgery frequently needed repeating, a search was undertaken for non-surgical, injection treatments using various anesthetics, alcohols, enzymes, enzyme blockers, and snake neurotoxins. Finally, inspired by Daniel Drachman’s work with chicks at Johns Hopkins, Alan B Scott and colleagues injected botulinum toxin into monkey extraocular muscles. The result was remarkable: a few picograms induced paralysis that was confined to the target muscle, long in duration, and without side-effects.
Serious adverse reactions, including excessive weakness, dysphagia, and aspiration pneumonia, with some adverse reactions associated with fatal outcomes, have been reported in patients who received BOTOX injections for unapproved uses. In these cases, the adverse reactions were not necessarily related to distant spread of toxin, but may have resulted from the administration of BOTOX to the site of injection and/or adjacent structures. In several of the cases, patients had pre-existing dysphagia or other significant disabilities. There is insufficient information to identify factors associated with an increased risk for adverse reactions a ssociated with the unapproved uses of BOTOX. The safety and effectiveness of BOTOX for unapproved uses have not been established.
It is not known whether BOTOX® is safe or effective to treat increased stiffness in upper limb muscles other than those in the elbow, wrist, fingers, and thumb, or in lower limb muscles other than those in the ankle and toes. BOTOX® has not been shown to help people perform task-specific functions with upper limbs or increase movement in joints that are permanently fixed in position by stiff muscles. BOTOX® is not meant to replace existing physical therapy or other rehabilitation that may have been prescribed.