Evaluating the Safety of Galcanezumab, a CGRP Treatment
by Deena Kuruvilla, MD
An exciting era of migraine treatments may be fast approaching. Treatments targeting calcitonin gene related peptide (CGRP), a peptide which mediates pain, are being studied for the prevention of migraine. Thus far, we do not have a preventive medication specifically developed for the treatment of migraine. Some of our current preventive treatments include botulinum toxin, antihypertensive, antiepileptic and antidepressant medications which were all initially developed for other conditions.
A phase 2b randomized clinical trial studying the efficacy of galcanezumab was published in JAMA in December 2017. It showed that monthly injections for a duration of three months was helpful in reducing migraine headache days by around 4 days in 120 mg and 300 mg doses versus a reduction of around 3 days in placebo.
While this is an exciting time for migraine treatments, one concern is the safety of these medications. This month we are featuring an article from Cephalalgia which studies the safety of one of these medications; galcanezumab. This is a phase 2b, multicenter, double-blind, randomized placebo-controlled study that evaluated how safe and helpful this drug is. The drug was specifically studied in patients with episodic migraine with headaches occurring 4-14 days in a 28 day period. 238 patients were in the galcanezumab treatment group and 120 patients were treated with placebo. During the study, blood pressure, pulse, weight, temperature, electrocardiogram and blood work were measured and not altered significantly by the drug.
Serious adverse events included appendicitis, Crohn’s disease, suicidal ideation and tongue tie in a baby born to a father who received galcanezumab, visual changes described as spots in the eye, abdominal pain, prolapsed uterus, urinary tract infection and upper limb fracture. The investigator and study sponsor claim these adverse events are likely not caused by galcanezumab. None of these events were seen in the placebo treated patients.
Other adverse events include injection site discomfort and upper respiratory infections. Injection site discomfort was more commonly seen in those treated with galcanezumab 300 mg and nasopharyngitis more common in those on low dose galcanezumab 5mg.
In the future, it will be interesting to see how this family of medications change the scope of migraine management.