An experimental treatment for Alzheimer's disease called NGD 97-1, which had appeared promising in animal studies, has proven ineffective in a phase II human clinical trial, according to Neurogen Corporation.

In studies performed on laboratory animals, NGD 97-1 selectively reduced the activity of the neurotransmitter gamma-aminobutyric acid (GABA) in the memory centers of the brain, improving cognitive function. This approach differs from that of drugs currently on the market for the treatment of Alzheimer's disease.

But Neurogen said its compound "did not show a therapeutic effect" in a phase II trial involving 200 patients with Alzheimer's disease that was conducted by research partner Pfizer Inc.

"While we are disappointed that NGD 97-1 did not work, we recognize that the business of new drug discovery and development is one of high attrition," said William H. Koster, President and CEO of Neurogen.

Other sources: Neurogen Corp.