Patient experience with non-invasive vagus nerve stimulator: gammaCore patient registry.
gammaCore is cleared by the FDA for acute and preventive treatment of cluster headache and the acute treatment of migraine in adults. Previously, only 2 treatments were approved for acute treatment of cluster headache while none were approved for preventive treatment. Following the initial FDA clearance, based on the ACT-1 and ACT-2 studies, a gammaCore Patient Registry (GPR) was designed to provide insights on the use of gammaCore and prescription patterns in the real-world setting and to characterize respective benefits and challenges during the acute treatment of episodic cluster headache. GPR was a prospective observational registry in which patients with episodic cluster headache (3rd edition of the International Classification of Headache Disorders criteria) who were prescribed gammaCore were invited to voluntarily enroll and provide information on their experiences between July 2017 and June 2018. Participants provided baseline information and were trained to self-administer treatment with gammaCore for cluster pain. Participants were also requested to record information for each cluster attack. Of the 182 patients who provided baseline demographic and cluster headache characteristics, 152 provided health index baseline data using EuroQol Health Index tool, 5-level format (EQ5D-5L) and 17 patients provided attack data on a total of 192 cluster headache attacks. The mean age was 49 years; 65% were male and 82% were white; the mean number of months of known diagnosis of cluster headache was 57; the mean number of attacks per cluster headache 4-week period was 14; and the mean pain score was 3.7 (0-4 scale) with a mean attack duration of 74 minutes. Sixty-seven percent of patients had used preventive treatments and 83% had used abortive treatments for cluster headaches; 25% of participants reported at least 1 comorbidity. The mean EQ5D-5L score (scale 0-1) was 0.83. Of the 192 cluster headache attacks reported, gammaCore was used in 116 (60%) attacks. Within this group, the mean pain score at the start of the attacks was 2.7, the mean number of stimulations used was 3.6, and the pain score after 30 minutes was 1.3. At 30 minutes, the pain of 81 (70%) attacks was reduced to none (27%) or mild (43%) (a pain score of 0 or 1) and in 94 (81%) attacks, patients experienced a reduction of at least 1 point in the pain score. This real-world observational evidence suggests that gammaCore adds clinically meaningful value to patients with episodic cluster headache by providing rapid pain relief and confirms that there is significant interest among prescribers in providing this new treatment and technology. This evidence further supports the need to redefine gammaCore as no longer investigational or experimental during considerations for reimbursement.