A new clinical trial finds that two non-steroidal, anti-inflammatory drugs (NSAIDs) do not slow the rate of cognitive decline in people with mild to moderate Alzheimer's disease (AD). The multicenter study, supported by the National Institute on Aging (NIA) and reported in the June 4, 2003, issue of the Journal of the American Medical Association (JAMA), is the first clinical trial to prospectively test rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, and naproxen, a non-selective NSAID, in people with AD.
After 12 months of treatment, both the rofecoxib and naproxen groups showed cognitive declines similar to those found in the placebo group. While the results do not eliminate the possibility of a very small beneficial effect, analysis indicates that it is highly unlikely that naproxen or rofecoxib treatment reduces the one-year rate of cognitive decline, even by as much as one-third.
The investigators, led by principal investigator Paul S. Aisen, M.D., of Georgetown University Medical Center, Washington, D.C, randomly assigned the study's 351 participants to one of three treatment groups: rofecoxib, naproxen, or placebo. Cognition was measured before and after treatment by scores on the Alzheimer's Disease Assessment Scale, a test evaluating memory, attention, reasoning, language, and orientation. After 12 months of treatment, both the rofecoxib and naproxen groups showed cognitive declines similar to those found in the placebo group. While the results do not eliminate the possibility of a very small beneficial effect, analysis indicates that it is highly unlikely that naproxen or rofecoxib treatment reduces the one-year rate of cognitive decline, even by as much as one-third.
Although the study failed to show a treatment benefit in people who already have AD, NSAIDs still could prove to be effective in preventing the disease, says Neil Buckholtz, Ph.D., chief of the NIA's Dementias of Aging Branch. An NIA-supported prevention trial of NSAIDs is on-going.
In an editorial in the same issue of JAMA, neuroepidemiologist Lenore Launer, Ph.D., of the NIA's Laboratory of Epidemiology, Demography and Biometry, points out that the individuals participating in this study met specific criteria and the outcome could be different, and possibly beneficial, in another group of people with AD or in those at risk for the disease.
The study was conducted at 40 centers nationwide organized under the Alzheimer's Disease Cooperative Study (ADCS), a consortium of academic and other research centers supported by the NIA to coordinate and facilitate the clinical testing of compounds to prevent AD or delay the onset of its symptoms. The NIA, part of the National Institutes of Health (NIH) at the U.S. Department of Health and Human Services, was the primary funder of the trial, with additional support provided to Georgetown University by the National Center for Research Resources, also part of the NIH.
The rationale for the study was based on previous findings that inflammation is a central feature of AD. The disease is an irreversible progressive brain disorder that occurs gradually and results in memory loss, behavior and personality changes, and cognitive decline.
The NIA is the lead federal agency conducting and supporting research on AD and the aging brain. Its Alzheimer's Disease Education and Referral (ADEAR) Center website offers information on age-related memory change, including a list of clinical trials testing possible therapies for AD, at www.nia.nih.gov/alzheimers. The public may also contact ADEAR at 1-800-438-4380.