Review of non-invasive vagus nerve stimulation (gammaCore): efficacy, safety, potential impact on comorbidities, and economic burden for episodic and chronic cluster headache.

The FDA has cleared gammaCore (non-invasive vagus nerve stimulator [nVNS]) for the treatment of episodic cluster headache (eCH). With the exception of subcutaneous sumatriptan, all other treatments are used off label and have many limitations. The FDA approval process for devices differs from that of drugs. We performed a review of the literature to evaluate new evidence on various aspects of gammaCore treatment and impact. The ACute Treatment of Cluster Headache Studies (ACT1 and ACT2), both double-blind sham-controlled randomized trials, did not meet the primary endpoints of the trials but each demonstrated significant superiority of gammaCore among patients with eCH. In ACT1, gammaCore resulted in a higher response rate (RR) (RR, 3.2; 95% CI, 1.6-8.2; P = .014), higher pain-free rate for >50% of attacks (RR, 2.3; 95% CI, 1.1-5.2; P = .045), and shorter duration of attacks (mean difference [MD], -30 minutes; P <.01) compared with the sham group. In ACT2, gammaCore resulted in higher odds of achieving pain-free attacks in 15 minutes (OR, 9.8; 95% CI, 2.2-44.1; P = .01), lower pain intensity in 15 minutes (MD, -1.1; P <.01), and higher rate of achieving responder status at 15 minutes for ≥50% of treated attacks (RR, 2.8; 95% CI, 1.0-8.1; P = .058) compared with the sham group. The PREVention and Acute Treatment of Chronic Cluster Headache (PREVA) study also demonstrated that gammaCore plus standard of care (SOC) was superior to SOC alone in patients with chronic cluster headache (CH). Medical costs, pharmacy refills, and pharmacy costs were higher in patients coded for CH in claims data compared with controls with nonheadache codes. gammaCore is easy to use, practical, and safe; delivery cannot be wasted; and patients prefer using gammaCore compared with SOC. The treatment improves symptoms and reduces the need for CH rescue medications. Current US reimbursement policies, which predate nVNS and are based on expensive, surgically implanted, and permanent implanted vagus nerve stimulation (iVNS), need to be modified to distinguish nVNS from iVNS. gammaCore, cleared by the FDA in April 2017, provides substantial value to patients and also to payers. There is sufficient evidence to support the need to modify current reimbursement policies to include coverage for gammaCore (nVNS) for eCH.