ImThera Medical Generating Buzz Over Neurostimulation for Sleep Apnea

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Some 800,000 people in the U.S. are diagnosed each year with obstructive sleep apnea, in which the tongue relaxes during the onset of sleep to the point of physically blocking much of the upper airway. The condition often causes repeated interruptions of sleep, which can lead to increased blood pressure, coronary problems, and diabetes.

The established treatment is a respirator-like gadget that a patient is supposed to wear while sleeping. But nearly half of the people who are directed by their doctors to use these “continuous positive airway pressure,” or CPAP, devices simply can’t or won’t comply, according to Terry Davidson, a professor of head and neck surgery at the UC San Diego School of Medicine. Davidson says he also is pessimistic about surgeries that are intended to move the tongue forward and away from the throat.

A San Diego medical device startup where Davidson is Chief Medical Officer is now testing a new approach, which uses an implanted electronic device to transmit low-current neurostimulation to the tongue. The steady electric current causes the tongue muscle to tighten, so it pulls away from the upper airway. The company, ImThera Medical, announced in December that it had implanted its technology in two obstructive sleep apnea patients in Belgium.

Marcelo Lima, ImThera’s founding chairman and CEO, tells me he views the non-compliant CPAP patients as an ideal market for ImThera’s technology. The company is in clinical trials only in Europe, and intends to implant devices in 10 more patients as part of those studies. In the European trials, a surgeon implants ImThera’s pacemaker-like device in the upper chest, just under the skin, and extends a wire to a multi-contact electrode in the jaw. From there, the surgeon attaches the electrodes to the hypoglossal nerve, which controls multiple muscles of the tongue. The company has posted a YouTube video that explains it all here.

The implanted electronic device is programmed a couple of weeks following the surgery to send just enough electricity to the nerve to deliver what Lima calls “awake muscle tone to the sleeping tongue.” A handheld radio-frequency wand is used to turn the implanted device on and off, and to recharge it.

Ofer Jacobowitz, an assistant professor in Columbia University’s Department of Otorhinolaryngology/Head and Neck Surgery, describes neurostimulation as “an exciting new approach” for treating obstructive sleep apnea.

But Jacobowitz, who has no vested interest in ImThera, told me by e-mail: “Neurostimulation of the tongue will need to be studied for effectiveness and patient adherence. Effectiveness could depend on [the] algorithm of stimulation, which may need to be personalized. Neurostimulation may not be effective for all comers, and stimulation may not be tolerated by all.” Jacobowitz also tells me there are many alternatives that are less invasive for sleep apnea patients, including oral appliances, surgery (which he says can be successful), weight loss, positional therapy, and Expiratory Air Pressure (EPAP) devices.

Marcelo Lima

Marcelo Lima

Lima says he co-founded ImThera in 2004, taking a board seat while he was still president of Visage Imaging, a Carlsbad, CA-based subsidiary of Massachusetts’ Mercury Computer Systems that specializes in computerized processing and visualization of diagnostic medical imaging technologies. Lima says he raised $5.1 million from angel investors, initially to better understand how the hypoglossal nerve works and subsequently to develop ImThera’s neurostimulation technology.

At the time of ImThera’s founding, Lima says, neurostimulation technologies had advanced across a broad front in previous years, and implantable devices were successfully being used to block chronic back pain in the spine, control epileptic seizures, and even to stimulate the sacral nerve to control incontinence. He estimates that such devices represent a $4 billion market that is dominated by major companies like Boston Scientific and Medtronic, and which has been growing at 18 percent annually.

Lima, who began working on ImThera full-time just last year, says the six-year-old company currently has just five full-time and six part-time employees. He recruited UCSD’s Davidson to serve as ImThera’s chief medical officer, and says he is raising an additional $3.5 million from individual investors in a secondary round that is expected to close this month.

Meanwhile, CPAP devices are still considered the established therapy for patients with obstructive sleep apnea. Companies that manufacture CPAP machines include Philips Respironics, Covidien, and ResMed.

Since it was founded 11 years ago, Poway, CA-based ResMed has grown to be a major medical device company—with more than 2,000 employees and sales last year of nearly $921 million. That accounts for almost a third of the estimated $3 billion market for CPAP devices in the U.S., a market that is growing by an estimated 20 percent a year. Such growth helps to explain Lima’s optimism for ImThera, which plans to complete mid-stage clinical trials in Europe this year and begin clinical trials in the U.S. by the end of 2010. It also helps to explain why two rival startups, Apnex Medical and Inspire Medical Systems, were founded near Minneapolis to develop similar technology.

So, as an early stage medical device startup, ImThera faces many challenges in establishing its technology. Still, as Davidson puts it, “If we can pull this off, it will be as sensational as spinal neurostimulation and pacemakers. It’s really sensational.”

Bruce V. Bigelow is the editor of Xconomy San Diego. You can e-mail him at bbigelow@xconomy.com or call (619) 669-8788 Follow @bvbigelow

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