NeuRx Diaphragm Pacing System Approved for ALS

by Amy Madsen on Thu, 2011-09-29 06:16

The NeuRx Diaphragm Pacing System, which may forestall the need for invasive ventilation, has been approved by the FDA for humanitarian use in ALS

Article Highlights:
  • The NeuRx Diaphragm Pacing System, developed by Synapse Biomedical, has been approved as a "humanitarian use device" by the U.S. Food and Drug Administration to treat respiratory insufficiency in ALS.
  • The system is designed to supplement breathing efforts and help preserve diaphragm muscle function; it may delay or negate the need for invasive tracheostomy ventilation and can be used in conjunction with noninvasive ventilation.
  • The pacing system will help people with ALS who still have some preservation of the diaphragm (the main muscle used in breathing) and also in the nerves that normally control its movement. 
  • The device will be available for physicians to prescribe in the near future.

The U.S. Food and Drug Administration has approved the NeuRx Diaphragm Pacing System for treatment of hypoventilation (inadequate breathing) in amyotrophic lateral sclerosis (ALS).

The DPS received FDA approval as a "humanitarian use device" (HUD), a designation given to medical devices intended for use in rare diseases. The FDA requires sufficient evidence that HUD devices do not pose "an unreasonable or significant risk of illness or injury, and that the probable benefit to health outweighs the risk of injury or illness from its use."

In people with ALS who have chronic breathing problems and whose primary breathing muscle, the diaphragm, still is able to respond to electrical stimulation, the pacing system may forestall or negate the need for invasive ventilation (ventilation via tracheostomy, or an opening in the neck).

The device does not treat the underlying molecular mechanisms that cause ALS, so it is unable to slow, stop or reverse the disease course. However, the treatment may improve quality of life.

"Approval of NeuRx DPS, with its potential to improve both survival and quality of life, is great news for the ALS community," said Valerie Cwik, MDA medical director and executive vice president for research. "MDA is very pleased that NeuRx DPS will now be a treatment option for individuals with ALS across the United States."

DPS System
A diaphragm pacing system, such as this NeuRx DPS, uses electrodes to rhythmically stimulate the diaphragm. The Synapse website includes a video showing how DPS works in ALS. Illustration courtesy of Synapse Biomedical.

FDA approval was announced by the system's developer, Synapse Biomedical, Sept. 29, 2011. Synapse says it plans to work closely with medical professionals at MDA/ALS centers to facilitate access to the NeuRx DPS treatment for those who are interested and eligible.

About the NeuRx diaphragm pacing system (DPS)

The DPS requires minimally invasive laparoscopic surgery, in which electrodes are surgically implanted in the diaphragm, a dome-shaped sheet of muscle that extends across the bottom of the rib cage and plays an important function in respiration.

The device then activates the diaphragm muscle, not only supplementing the patient's breathing ability, but also delaying diaphragm atrophy (shrinkage) and the need for invasive ventilation, says Synapse.

In order to benefit from the pacing system, people with ALS must have adequate function not only in the diaphragm, but in the phrenic nerves, which stimulate this muscle. If the nerves or diaphragm have deteriorated too much, the device is not likely to have any benefit.

The DPS can be used in conjunction with noninvasive positive-pressure ventilation (i.e., BiPAP), received through oral or nasal delivery.

Synapse Biomedical reports the NeuRx DPS helps people with ALS "live longer and sleep better than the current standard of care alone." These findings came from a multicenter clinical trial that enrolled 106 patients and treated 86 for chronic hypoventilation at seven U.S. sites and one French site.

DPS development began in 1996, when Raymond Onders, co-founder of Synapse Biomedical, began clinical research aimed at helping patients with spinal cord injuries — including the late actor Christopher Reeve — breathe better. In 2004, this research expanded to include patients with ALS.

In late 2008, Onders presented results from two clinical trials of people with ALS who received NeuRx systems, which showed that trial participants tolerated the device well and that those with declining respiratory capacity during the lead-in period to the study showed a slower rate of decline after they had pacing systems implanted. Onders, who lost his sister to ALS in the past year, currently holds the Margaret and Walter Remen Chair in Surgical Innovation and is a professor of surgery at Case Western Reserve University School of Medicine in Cleveland.

Meaning for people with ALS

FDA approval "allows us to now offer individuals living with ALS more time to be able to breathe with their own muscles," Synapse Biomedical President and Chief Executive Officer Anthony R. Ignagni said in a press release.

The DPS should be available soon for physicians to prescribe. FDA approval also clears the way for potential insurance coverage of the device for people with ALS.

Those considering the device should discuss their current health problems and medications, as well as the possible benefits and risks of the new system, with their physicians.

MDA ALS Division Co-Chair Augie Nieto, who received an ALS diagnosis in 2005, participated in the clinical trial of the device that led to FDA approval. In the summer of 2011, Nieto underwent a tracheostomy and switched to invasive ventilation.

"Getting this device was one of the best decisions I’ve made since my diagnosis," Nieto said. "It helped me delay the need for a tracheostomy for more than six years after my diagnosis. Most people with ALS ultimately will face a decision about going on a vent. The pacer will help extend that decision while we help find a cure."

About breathing difficulties in ALS

Respiratory problems are one of the most serious medical complications in ALS and a major cause of death for those with the disease.

Breathing difficulties begin with the gradual loss of muscle-controlling nerve cells (motor neurons), and the concurrent deterioration and loss of function of the muscles responsible for breathing. Symptoms of respiratory insufficiency and distress include shortness of breath when lying down, or with exertion, and sleep disturbances.

For more information on breathing problems in ALS, see the MDA publications Breathe Easy: Respiratory Care in Neuromuscular Disorders, and How Does ALS Affect Breathing? in Chapter 5 of Everyday Life with ALS: A Practical Guide.

Editor's note: This story was updated Oct. 28, 2011, to reflect that the FDA approved the NeuRx Diaphragm Pacing System as a humanitarian use device.

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