Test of Alzheimer’s drug suspended

Test of Alzheimer’s drug suspended – tetrahydroaminoacridine

Test of Alzheimer’s Drug Suspended

FDA and the manufacturer of an experimental drug for Alzheimer’s disease are looking into cases of possible liver damage to see whether the problem is permanent and is actually caused by the drug. At FDA’s request, the firm, Warner-Lambert Company of Morris Plains, N.Y., suspended the study of tetrahydroaminoacridine (THA) on Oct. 23, 1987, about a month after the testing had begun.

Outsude experts in liver toxicity have been working with FDA and the firm in evaluating the drug. Depending on the evaluation, the agency may allow the tests in Alzheimer’s patients to resume, most likely at lower dosages.

Warner-Lambert provided regular safety updates to FDA from the very start of its clinical tests with THA. Thus, when blood samples from eights patients showed high levels of liver enzymes — a sign of possible liver damage — FDA learned about it right away. Because the problem was detected so promptly, fewer than 50 of the planned 300 patients had actually been enrolled in the study. Researchers at 17 centers across the country had been conducting the study with funding from the National Institute on Aging and the Alzheimer’s disease and Related Disorders Association.

The progressive mental impairment caused by Alzheimer’s disease disables about 2.5 million Americans each year. THA, one of several potential Alzheimer’s therapies being tested, gained national attention when favorable results of a study of the drug at the University of California, Los Angeles, were reported in the Nov. 13, 1986, New England Journal of Medicine. However, subsequent letters to the journal and an FDA inspection raised questions about the design and conduct of the study. The Warner-Lambert trial was intended to assess THA’s safety and effectiveness more conclusively.

Meanwhile, until the possibility of liver damage is resolved, it is particularly important that any illegally circulating THA note be used.

COPYRIGHT 1988 U.S. Government Printing Office

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