Information about Alzheimer's Research, Studies & Clinical Trials

Alzheimer's drug research has suffered a number of setbacks in recent years. Clinical trials of three promising agents—tramiprosate (Alzhemed), R-flurbiprofen (Flurizan), and the Alzheimer's vaccine AN-1792—were stopped because of lack of effectiveness or safety concerns. Despite these disappointments, Alzheimer's researchers are pushing forward to find treatments that will forestall or slow progression of the disease.

Immunotherapy & Alzheimer's Research

Investigators are exploring immunotherapy (manipulating the immune system to treat diseases) as a means of clearing amyloid plaque from the brain. Several experimental anti-amyloid vaccines are in clinical trials, including one known as ACC-001. Another type of immunotherapy being tested involves a monoclonal antibody called AAB-001 (bapineuzumab). The antibody, which is delivered through an infusion, binds to amyloid and removes it from the brain.

Statins & Alzheimer's Research

Cholesterol-lowering statin medications continue to be studied for their potential preventative or therapeutic effects on Alzheimer's disease. Researchers have speculated that lowering cholesterol levels may reduce the production of beta-amyloid or improve blood vessel functioning in the brain.

Statins also have an anti-inflammatory effect, which may target the brain inflammation associated with Alzheimer's disease. Several population studies have suggested that people who take a statin to lower their LDL ("bad") cholesterol levels have a reduced risk of developing the disease. However, other studies have not found this to be the case.

Anti-inflammatory Drugs & Alzheimer's Research

Researchers also continue to explore the potential benefits of nonsteroidal anti-inflammatory drugs (NSAIDs) and other anti-inflammatories, but recent evidence suggests that they may increase risk in people over age 65 or 70. NSAIDs are a class of drugs commonly used to treat arthritis and include medications like naproxen (Aleve and other brands) and ibuprofen (Motrin and other brands).

Study results have been conflicting, with earlier, retrospective studies suggesting that NSAID use can reduce the risk of developing dementia. A recent clinical trial, however, showed that those getting the drug experienced no benefit and may have been at increased risk.

NSAIDs can have side effects, such as fatigue, dizziness, high blood pressure, and gastrointestinal bleeding, and some of the medications have been linked to an increased risk of stroke and heart attack.

Several clinical trials are continuing to explore NSAIDs' potential role in Alzheimer's prevention and treatment. In the meantime, these drugs should not be taken in an attempt to prevent cognitive decline. While one physician has claimed that the rheumatoid arthritis drug etanercept (Enbrel) reduces Alzheimer's symptoms when injected through the spine, this potential benefit has not been found by others.

The Alzheimer's Association advises people with Alzheimer's and their families not to place "undue value on this new finding based on the dramatic language used in its description and the apparent immediate effect." Since Enbrel has been tested on only a small number of people with Alzheimer's, a benefit cannot be ruled out, but larger trials will be needed to determine whether this newer inflammation-fighting agent might have a role in Alzheimer's treatment.

Since it is given by injection and has serious side effects, including increasing the risk of tuberculosis, it is not likely to become a mainstream treatment.

Estrogen Therapy & Alzheimer's Research

Estrogen therapy's effects on cognitive function remain a puzzle to researchers. Observational studies have suggested that the risk of dementia is reduced by about 30% in postmenopausal women who take estrogen-replacement therapy. But in large clinical trials, giving postmenopausal women estrogen alone or estrogen plus progesterone has been ineffective in preventing dementia.

In fact, some evidence suggests that estrogen-replacement therapy may actually promote dementia. As a result, estrogen research has been curtailed, although not abandoned. A number of questions remain, such as whether the timing of estrogen-replacement therapy influences the hormone's effects on brain function.

Publication Review By: Peter V. Rabins, M.D., M.P.H.

Published: 11 Mar 2011

Last Modified: 23 Jun 2011