PHILADELPHIA – according to 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.
Calcitonin gene-related peptide (CGRP) has an important role in the pathogenesis of cluster headache. Galcanezumab ()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 ( ) and high-flow oxygen, but some patients do not respond to these therapies.
, 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.