BALTIMORE – A hand-held vagal nerve stimulator significantly decreased the frequency of cluster headache attacks per week, compared with the usual standard of care, based on data from a randomized trial of 97 patients.
The noninvasive device, called gammaCore, was associated with seven fewer weekly headache attacks when used in conjunction with sumatriptan and oxygen – significantly better than the one-attack reduction achieved with standard therapy alone, Eric Liebler reported at the annual meeting of the American Neurological Association.
Michele G. Sullivan/Frontline Medical Media
The use of rescue medications decreased significantly in the group using the device, said Eric Liebler.
“In this 2-month study, the external vagal nerve stimulator effected a significant improvement in the reduced rate of attacks and the 50% responder rate, with very few device-related adverse events,” said Mr. Liebler, vice president of scientific, medical, and governmental affairs for electroCore, the New Jersey–based company that manufactures the device.
The gammaCore device is used in Europe for the treatment of primary headache disorders. The device, which transmits mild current to the vagal nerve, is a small, hand-held unit that the patient uses twice each day. It’s thought to work by suppressing excessive extracellular glutamate in the trigeminal nucleus caudalis – a phenomenon that seems to stimulate trigeminal sensitization in migraine.
Patients are instructed to activate the device over the carotid pulse point on the neck for about 90 seconds. A conductive gel helps transmit mild current to the vagal nerve.
The 2-month Prevention and Acute Treatment of Chronic Cluster Headache (PREVA) trial examined the use of gammaCore in treating cluster headaches. The cohort included 97 patients who were randomized to the device plus the standard therapy or to standard therapy alone. At the end of the first month, patients in the combination group continued for another month while those in the standard-care group were offered a month of combination therapy.
The primary endpoint was the reduction in cluster headache attacks per week during the last 2 weeks of each month. Secondary endpoints included the number of patients with at least a 50% reduction in the number of cluster headaches per month and changes in the use of acute medications. The study also examined device safety and tolerability. Attack pain and duration are being assessed in a separate study, Mr. Liebler noted.
The mean age of the patients was approximately 44 years. Most were using medications (90%) and oxygen (68%), and the mean duration of their cluster headaches at baseline was about 28 minutes when they used these treatments. Without medications and oxygen, the headaches lasted a mean of 100 minutes. These patients expereinced about 70 cluster attacks in the month before randomization.
Patients in the combination group experienced a significant reduction in the number of cluster headache attacks per week (from 16 to 9 attacks). The change among those taking standard therapy alone was not significant (from 16 to 15 attacks).
In the intent-to-treat population, 38% of the combination group achieved at least a 50% decrease in headache days, compared with 8% of the standard-therapy group – a significant difference. In the full analysis, the device response numbers were better – 46% vs. 8%. The per protocol analysis included only those patients who used the device as instructed at least 80% of the time. The 50% responder rate in that group was 52% vs. 9% of the standard-treatment group.
Among the combination-therapy group, the use of rescue medications decreased significantly: from 7 to 3 times per month for subcutaneous sumatriptan and from 16 to 6 times per month for oxygen. Rescue-medication use was virtually unchanged among those who used standard therapy only.
Safety and tolerability was good. Most of the patients using the device (44) did experience an adverse event. Device-related events included dizziness (3), oropharyngeal pain (3), and neck pain (3). These events probably occurred because electrical current tends to spread to neck muscles, Mr. Liebler said. The sensations were transitory, he added.
Dr. Peter Goadsby, director of the headache center at the University of California, San Francisco, said that he has been “surprised” at the positive results seen in European patients. “These are medication-refractory patients, and about half of them had significant reductions in the frequency and severity of their cluster headaches, with a simultaneous decrease in the need for oxygen and steroids. They also seemed to feel that their steroids worked more efficiently,” when used in conjunction with the device, he said.
The study was sponsored by electroCore, and Mr. Liebler is a full-time employee of electroCore. Dr. Goadsby has served as a consultant for a number of pharmaceutical companies.