PHILADELPHIA – according to study results presented at the annual meeting of the American Academy of Neurology. The treatment has a similar safety profile in this patient population as it has among people with episodic or chronic migraine, said the researchers.
Dr. David W. Dodick
Calcitonin gene-related peptide (CGRP) has an important role in the pathogenesis of cluster headache. Galcanezumab (Emgality)is a humanized monoclonal antibody that binds to CGRP. Eli Lilly & Co. developed the molecule as a treatment for migraine. Cluster headache is characterized by recurrent unilateral headache attacks accompanied by autonomic symptoms. The most common acute treatments for cluster headache are sumatriptan (Imitrex) and high-flow oxygen, but some patients do not respond to these therapies.
David W. Dodick, MD, director of the headache, sports neurology, and concussion programs at Mayo Clinic in Phoenix, and colleagues conducted a trial to evaluate the efficacy and safety of galcanezumab in patients with episodic cluster headache.
After screening, participants underwent a prospective baseline diary phase for 7 consecutive days. The investigators subsequently randomized patients in equal groups to galcanezumab (300 mg subcutaneously) or placebo. Treatment was administered subcutaneously once monthly. The double-blind treatment period lasted for 8 weeks, and a washout period followed. The trial’s primary endpoint was the overall mean change from baseline in weekly cluster headache attack frequency during weeks 1-3, as recorded in patient diaries. The main secondary endpoint was the proportion of patients who had a reduction in weekly cluster headache attack frequency of 50% or more at week 3.
In all, 49 patients were randomized to galcanezumab, and 57 were randomized to placebo. Mean age was 45-47 years. Between 82% and 84% of patients were male. The mean number of weekly cluster headache attacks at baseline was approximately 17.5 in both groups.
During weeks 1-3, the mean change in weekly attack frequency was −8.7 in the galcanezumab group and −5.2 for controls. The difference between groups was statistically significant. The percentage of participants with a reduction in weekly attack frequency of at least 50% at week 3 was 76% for galcanezumab versus 57% for placebo. The between-group differences in these endpoints were statistically significant.
The discontinuation rate was 8% (4 participants) in the galcanezumab group and 21% (12 participants) in the placebo group. Eight participants (14%) in the placebo group discontinued treatment because of lack of efficacy, compared with one participant (2%) in the galcanezumab group. The researchers observed no clinically meaningful differences between treatment groups on tolerability or safety parameters except for a greater incidence of injection-site pain with galcanezumab versus placebo (8.2% vs. 0%).
Eli Lilly and Co. sponsored the study. Dr. Dodick has a consulting relationship with the company.
SOURCE: Bardos JN et al. AAN 2019, Abstract 02.004.