By delivering controlled electrical pulses to a portion of the brain linked to memory and alertness—and which forms part of a network involved in seizures—Medtronic aims to treat medication-resistant epilepsy patients using a deep brain stimulation implant similar to a cardiac pacemaker.
The medtech giant has begun rolling out its therapy in the U.S., with the treatment of its first commercially implanted patient after receiving a recent premarket approval from the FDA.
The therapy targets the brain’s anterior nucleus of the thalamus, to serve as an adjunctive treatment to reduce partial-onset seizures in adults resistant to at least three anti-epilepsy medications. According to statistics from the Epilepsy Foundation, one-third of the nearly 3.4 million Americans with epilepsy are estimated to be drug resistant.
In a long-term clinical study known as SANTE, first launched in 2003, Medtronic saw significant reductions in complex partial and severe seizures in patients averaging six or more seizures per month. After two years, 54% of 110 patients saw their seizure frequencies reduced by at least half, with 14 patients reporting as seizure-free for at least six months—and a median seizure frequency reduction of 75% after seven years.
"The commercial availability of DBS provides an important surgical treatment option for patients who suffer from epilepsy and do not respond to medication," said SANTE’s neurosurgical primary investigator Robert Gross, M.D., Ph.D., MBNA Bowman chair and professor at Emory University’s Department of Neurosurgery. “The first patient implanted since commercialization is doing very well. While it has only been two months since the system was turned on, his frequency of seizures has declined by more than 50%, and we expect improvement to increase further with additional programming sessions."
Medtronic also plans to launch a postmarket study of 140 participants in the U.S. and Europe, to evaluate safety and effectiveness outcomes over an additional three years.
Medtronic’s DBS systems were first approved in 1997, with more than 150,000 devices being implanted worldwide. The therapy is currently approved for treating the disabling tremors in Parkinson's disease, and under FDA Humanitarian Device Exemption approvals, the therapy can also be used for chronic intractable primary dystonia and severe, treatment-resistant obsessive-compulsive disorder.
In addition, a trio of health insurers—Aetna, HAP and Blue Cross Blue Shield CareFirst—have included the DBS therapy in their policies for epilepsy, as Medtronic works to secure coverage with additional payers.