Cortex Pharmaceuticals, Inc announced that the UK's Medicines and Healthcare product Regulatory Agency (MHRA) gave it permission to proceed with the clinical development of CX1739 in subjects with moderate to severe sleep apnea. The study will be conducted in a UK sleep unit using a double-blind, placebo-controlled design in 20 subjects.

Sleep apnea is a chronic disorder characterized by pauses in breathing during sleep, with the most common type being obstructive sleep apnea. Each episode, called an apnea, lasts long enough so that one or more breaths are missed. Such episodes occur repeatedly throughout sleep and may result in significantly reduced blood oxygenation. If left untreated, sleep apnea can lead to an increased risk of stroke, heart attacks, hypertension, obesity and type-II, maturity onset diabetes, as well as an increased risk of accidents due to excessive sleepiness. The National Institute of Health estimates that over 12 million American adults have sleep apnea. There is currently no drug treatment option available for sleep apnea and the market is considered a multi-billion dollar opportunity in North America alone.

"CX1739 has been very well tolerated in phase-I healthy volunteer studies, and we are excited to be able to proceed with an efficacy study in sleep apnea," said Dr Mark Varney, president and chief executive officer of Cortex. "We anticipate starting subject enrolment in February and completing the study in the second quarter of 2009."

Data obtained from animal studies have demonstrated that Ampakine compounds can specifically stimulate breathing by activating regions in the brain stem. In 2008, Cortex announced positive results of two clinical studies that demonstrated the Ampakine CX717 could prevent the depression of breathing induced by an opioid analgesic. Further analyses of these clinical studies also showed that CX717 reduced both the number and duration of apnea events caused by the opioid. Studies in animals suggest that CX1739 is approximately three times better than CX717 at reversing breathing depressed by opioids. CX1739 also stimulates another brain region that regulates muscle tone in the upper airways. "Our hypothesis is that by stimulating breathing and increasing muscle tone in the upper airways, CX1739 will be effective in maintaining breathing throughout the night in sleep apnea patients," commented Dr Varney.

Cortex, located in Irvine, California, is a neuroscience company focused on novel drug therapies for treating psychiatric disorders, neurological diseases and brain-mediated breathing disorders.