Post-approval interim data on ALS neurostim device confirms survival benefit

NeuRx Diaphragm Pacing System--Courtesy of Synapse

When the FDA approved the NeuRx Diaphragm Pacing System to treat chronic hypoventilation in amyotrophic lateral sclerosis (ALS) patients in September 2011 under the Humanitarian Device Exemption (HDE), the agency required an extensive post-marketing study. Now Synapse Biomedical, which markets the neurostimulator breathing device, has reported interim data from that study that's a bit better than the approval data.

The post approval NeuRx study had enrolled the required 60 patients at August 2014; the FDA requested that the data extend for an average of three years at three-month intervals. The agency specified that the trial must go on until the last patient enrolled had been evaluated for two years--which puts that completion date at roughly August 2016. The HDE exemption program is a faster approval route open to devices that are intended for use on fewer than 4,000 people in the U.S. per year.

In the interim analysis, Synapse found that patients had a median survival of 20.9 months post-implant; the original pivotal data in 106 patients reported 19.7 months of median survival.

The NeuRx DPS device is a neurostimulator with implanted electrodes that deliver stimulation to the muscles and nerves of the diaphragm to ease breathing. It's a four-channel, battery-powered device. In ALS, the FDA approved it for patients with "a stimulatable diaphragm (both right and left portions) as demonstrated by voluntary contraction or phrenic nerve conduction studies, and who are experiencing chronic hypoventilation (CH), but not progressed to an FVC less than 45% predicted," according to the approval letter.

The device has been CE-marked since November 2007 to treat patients with diaphragm dysfunction. It also has an FDA approval for ventilator dependency from spinal cord injury that dates from June 2008. The minimally invasive device requires an outpatient procedure for placement. It includes four electrodes that are implanted in the diaphram, a fifth electrode implanted under the skin, an electrode connector, an external pulse generator, and a cable to connect the electrode to the EPG.

Synapse expects that the addition of the NeuRx DPS to the standard-of-care can help ALS patients to live longer and to sleep better.

"The PAS study supports our original IDE pivotal findings that DPS can extend patient survival," said Synapse President and CEO Anthony Ignagni in a statement. "We are confident in the safety and therapeutic utility of DPS when patients are carefully selected and screened according to proper criteria."

"We are committed to ongoing clinical research studies such as PAS and the NEALS randomized controlled trial to further clarify the safety and benefit of diaphragm pacing for people with ALS," added Mike Fritz, the Synapse VP of clinical and regulatory affairs.

- here is the statement