Clinical trials have sounded alarm bells for another promising new drug, this one to treat Alzheimer's patients. After consulting with Food and Drug Administration regulators, Johnson & Johnson said the safety of its drug Reminyl is now under review.

Reminyl is currently approved in 69 countries worldwide for treatment of mild to moderate Alzheimer's disease. No regulatory applications have been submitted for the potential use of the drug for the treatment of mild cognitive impairment anywhere in the world, and the company said none are planned.

Johnson & Johnson said the review was initiated as a result of a preliminary safety assessment of an imbalance of mortality in two mild cognitive impairment clinical trials submitted to health authorities worldwide by Johnson & Johnson Pharmaceutical Research & Development, L.L.C., in August 2004.

The clinical trial results also were presented last year at two international scientific forums: the International Congress of Alzheimer's Disease (ICAD) and the Alzheimer's Association Research Roundtable Mild Cognitive Impairment Meeting.

Approximately 2,000 patients from 16 countries were enrolled in the GAL-INT-11 and GAL-INT-18 studies, which were designed to evaluate a potential decrease in the rate of progression from mild cognitive impairment to dementia in subjects treated with the drug.

In the two-year trials, the company says 15 patients taking Reminyl died, compared with five who were taking a placebo. Not all causes of death were the same, but apparently enough were attributed to heart attacks or strokes to cause concern and trigger a review.

It was a series of clinical trials that caused new concerns about the safety of COX-2 inhibitors prescribed to treat arthritis. Merck voluntarily withdrew Vioxx while Pfizer has suspended advertising for Celebrex and Bextra. In those cases, clinical trials pointed to an increase risk of heart attack or stroke for people taking the drugs.

Johnson & Johnson said mortality rates were low in both the Reminyl and placebo groups in the two-year study compared to expected rates in this population or in patients with Alzheimer's disease. The clinical trials, it said, showed a higher relative mortality rate in patients with mild cognitive impairment treated with Reminyl than in patients treated with placebo.

The company said it is currently analyzing additional data from these studies, including information retrieved from subjects who had dropped out of the trials, and is discussing the results with regulatory authorities.