Use of study drugs in a large, federally funded Alzheimer prevention trial has been suspended following a decision by the study's leadership on Dec. 17, 2004.
The Alzheimer's Disease Anti-Inflammatory Prevention Trial (ADAPT), sponsored by the National Institutes of Health (NIH), was designed to test whether either of two nonsteroidal anti-inflammatory drugs (NSAIDs) could prevent Alzheimer's in older adults at increased risk due to a family history of the disease. Naproxen (sold under such trade names as Aleve, Naprosyn and Anaprox) and celecoxib (Celebrex) were the two NSAIDs under investigation in the trial.
Although administration of study drugs is suspended, researchers will continue to examine and monitor ADAPT's approximately 2,400 participants, who have been taking naproxen, celecoxib or a placebo for up to three years.
The suspension came following concerns over data from a cancer prevention trial unrelated to ADAPT suggesting that celecoxib may be associated with an increased risk of heart problems. Use of study drugs in the cancer trial was also suspended on Dec. 17. Although preliminary data from ADAPT did not link celecoxib to a statistically significant increase in heart problems, preliminary ADAPT data did suggest a possible link between long-term use of naproxen and increased risk of heart attack and stroke. Naproxen, approved by the Food and Drug Administration (FDA) in 1976 and sold over the counter since 1994, has never previously been linked to cardiovascular problems, although the drug has not been tested for long-term use in placebo-controlled clinical trials.
Last September, rofecoxib (Vioxx), a drug in the same NSAID subclass as celecoxib, was withdrawn from the market after data from another prevention trial highlighted potential cardiovascular problems. Valdecoxib (Bextra), another drug in this subclass, has also been linked to cardiovascular problems following heart bypass surgery and is not recommended for use by individuals at high risk for heart disease.