Neurex Corp. on Thursday submitted the first investigationalnew drug application to FDA for a neuron-specific channelblocker that may protect the brain from damage followingoxygen deprivation.

The Menlo Park, Calif., company first proposes using itssynthetic compound, SNX-111, in cardiac arrest patients, PaulGoddard, chief executive officer, told BioWorld.

"There's a 24-hour window of opportunity," he explained, "andthe compound appears very effective in animal models duringthat time."

Lack of oxygen caused by a heart attack, near drowning orhead injury triggers a series of events that lead to neuronsbecoming overexcited. When oxygen is restored, the brain cellsstart a biochemical cascade that causes extensive damage and adecrease in neurological function over hours and days, he said.

A drug that specifically blocks calcium channels mayselectively prevent the calcium-dependent release ofneurotransmitters that causes the neurons to becomeoverexcited in the first place.

Channel blockers used in hypertension and angina have beenineffective in neurons because these central nervous systemcells also contain their own distinct channels, which are thefocus of the company's research.

Of the 200,000 patients per year in the U.S. whe are initiallyresuscitated outside the hospital following cardiac arrest, morethan 190,000 suffer some form of neurological damage or diefrom related neurological complications.

SNX-111, a synthetic analog of a natural compound, wasmodeled on understanding of the receptor it blocks, Goddardsaid.

Since the compound selectively affects the central nervoussystem, the company plans to test its efficiency in blockingpain sensations that travel along the spinal cord.

Neurex's closest competitor, Cambridge NeuroScience Inc.(NASDAQ:CNSI) of Cambridge, Mass., has received a smallbusiness innovation research (SBIR) grant to identify calciumchannel blockers, such as a compound to inhibit the release ofthe neurotransmitter glutamate. Cambridge Neuro also expectsto file an IND for a potential drug to protect neurons fromdamage following a loss of blood supply to the brain.

Although Neurex filed for an initial public offering a year ago,the company postponed the IPO "due to adverse conditions,"Goddard said, but continues to review the prospects "on aregular basis."

-- Nancy Garcia Associate Editor

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