The UK’s Medicines and Healthcare Product Regulatory Agency (MHRA) granted permission to Cortex Pharmaceuticals Inc, Irvine, Calif, to proceed with the clinical development of AMPAKINE CX1739 in subjects with moderate to severe sleep apnea. Data from animal studies have shown that AMPAKINE compounds demonstrated the ability to stimulate breathing by activating regions in the brain stem. The study will be conducted in a UK sleep unit using a double-blind, placebo-controlled design in 20 subjects.

“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,” says Mark Varney, PhD, president and chief executive officer of Cortex. “We anticipate starting subject enrollment in February and completing the study in the second quarter of 2009.”

In 2008, Cortex released positive results of two clinical studies that demonstrated the AMPAKINE CX717 could prevent the depression of breathing induced by an opioid analgesic. Further analyses showed that CX717 reduced both the number and duration of apnea events caused by the opioid.

According to Cortex, recent studies suggest that CX1739 is approximately three times better than CX717 at reversing breathing depressed by opioids. Additionally, CX1739 also stimulates an additional 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,” says Varney.