Epilepsy Market Poised for New Device Competition

by Warren Grill, senior technical editor and James Cavuoto, editor

For well over a decade, Cyberonics has enjoyed a monopoly on device-based approaches to treat epilepsy. The company’s VNS therapy system stimulates the vagus nerve to reduce the frequency or intensity of seizures in people with medically-refractory epilepsy. A long-term clinical study presented at the American Epilepsy Society’s 63rd Annual Meeting, held earlier this month in Boston, supported the efficacy of VNS.

Robert Elliott and his colleagues at NYU Langone Medical Center reported on 436 patients who had at least one year of follow-up. Almost 65 percent of the patients experienced at least a 50-percent reduction in seizure frequency, and more than 40 percent of patients experienced at least a 70 percent reduction in seizure frequency. “VNS therapy continues to be an effective way to treat medically refractory epilepsy while possibly improving the quality-of-life for patients,” said Elliot.

The VNS device was originally approved by the FDA in 1997, and worldwide has been implanted in more that 50,000 patients. However, the recent positive results from clinical trails from two other epilepsy devices now threaten Cyberonics’ monopoly. NeuroPace, a privately held company in Mountain View, CA, revealed at the AES meeting that the pivotal clinical trial of is Responsive Neural Stimulation System had met its primary endpoint and announced their intention to submit a PMA application to the FDA in 2010. In contrast to the Cyberonics VNS device, the RNS system records ongoing electrical activity from the brain, and stimulates the brain in response to specific patterns of activity to interrupt nascent seizures.

The NeuroPace trial enrolled 191 people with partial onset epilepsy who had failed to respond to at least two medications across 31 centers in the U.S. During the double-blind portion of the trial, the device reduced seizure frequency by 29 percent, as compared to only a 14 percent reduction in those who had a placebo treatment. During the subsequent 12-week open label period of the trial, 47 percent of patients experienced at least a 50 percent reduction in seizure frequency. There were no serious unanticipated device related adverse events reported in the trial. Each participant will be evaluated in the pivotal trial for two years after being implanted with the RNS System.

Medtronic, Inc. also recently reported positive results from the SANTE (Stimulation of the Anterior Nucleus of the Thalamus in Epilepsy) trial of their DBS technology. The prospective, randomized, double-blind trial studied 91 patients with refractory epilepsy with partial-onset seizures. Compared to antiepileptic medications, DBS reduced seizure frequency by 41 percent for one year, 56 percent for two years, and 68 percent for three years. Medtronic’s PMA application is expected to go to FDA panel early next year, with uncertain timing for subsequent approval.

The likely presence of at least three neurotech device competitors in the epilepsy market is bound to create opportunities for both clinicians and patients. Neurologists and epilepsy specialists contacted by Neurotech Reports say they would be most interested in an intervention that comes closest to the goal of eliminating seizures in individuals with epilepsy. All other things being equal, the device deemed to be least invasive would have an advantage. Because it does not involve brain surgery, VNS might be seen as the least invasive therapy, and DBS might be next, given the amount of skull removed in the RNS implantation procedure.


 

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