Alzheimer's treatments: What's on the horizon?

Alzheimer's treatments currently work by temporarily improving symptoms of memory loss and problems with thinking and reasoning. These Alzheimer's treatments boost performance of specialized biochemicals that carry information from one brain cell to another. But they don't stop the underlying decline and death of brain cells. As more cells die, Alzheimer's continues to progress.

Many experts are cautiously hopeful about developing Alzheimer's treatments that can stop or significantly delay the progression of Alzheimer's. A growing understanding of how the disease disrupts the brain has led to potential Alzheimer's treatments that short-circuit fundamental disease processes. Future Alzheimer's treatments may focus on combinations of medications like those used for many cancers and AIDS rather than a single "magic bullet." The following treatment options are among the strategies currently being studied.

Taking aim at plaques

Some of the new Alzheimer's treatments furthest along in development target plaques — microscopic clumps of the protein beta-amyloid. Plaques have long been considered an Alzheimer's disease hallmark. Two strategies aimed at beta-amyloid include immunizing the body against it and blocking its production:

• Immunization strategies may prevent beta-amyloid from clumping into plaques and help the body clear it from the brain. The first Alzheimer's vaccine to reach clinical trials mobilized a person's own immune system to attack beta-amyloid. Researchers stopped this study ahead of time when some participants developed acute brain inflammation. Although the trial ended before researchers could fully assess the vaccine's effectiveness, the study demonstrated that beta-amyloid immunization could have a powerful impact on the brain.

  Most current immunization studies focus on administering antibodies against beta-amyloid from outside sources instead of ramping up a person's own immune system. One large research effort is exploring the value of intravenous (IV) infusions of a product derived from donated blood. This product contains naturally occurring anti-amyloid antibodies from the donors. Several other studies are investigating laboratory-engineered (monoclonal) antibodies.

• Production blockers may reduce the amount of beta-amyloid formed in the brain. Research has shown that beta-amyloid is produced from a "parent protein" in two steps performed by two different enzymes. Several experimental drugs aim to block the activity of the second enzyme. The first enzyme may also be a future target.

Keeping tau from tangling

A vital brain cell transport system collapses when a protein called tau twists into microscopic fibers called tangles — another hallmark brain abnormality of Alzheimer's. Keeping tau from forming tangles offers another potential drug target. One medication currently under investigation is taken as a nasal spray.

Reducing inflammation

Alzheimer's causes chronic, low-level brain cell inflammation. Based on success in treating inflammation elsewhere in the body, researchers are attempting to develop drugs that zero in on specific inflammatory processes at work in Alzheimer's disease.

Capitalizing on the heart-head connection

Growing evidence suggests that brain health is closely linked to heart and blood vessel health. Your brain is nourished by your arteries. The risk of developing Alzheimer's appears to increase as a result of many conditions that damage the heart or arteries. These include high blood pressure, heart disease, stroke, diabetes and high cholesterol. In addition, the strongest known genetic Alzheimer's risk factor is one form of a gene for apolipoprotein E, a protein that carries cholesterol in the blood.

A number of studies are exploring how best to capitalize on this heart-head connection. Strategies under investigation include:

• Current drugs for heart disease risk factors. Researchers are investigating whether drugs currently used to treat high blood pressure, diabetes and high cholesterol may also help people with Alzheimer's or reduce the risk of developing the disease.
• Drugs aimed at new targets. Additional projects are looking more closely at how the connection between heart disease and Alzheimer's works at the molecular level to find new drug targets.
• Heart-healthy lifestyle choices. Still other studies are exploring whether lifestyle choices with known heart benefits, such as exercising on most days and eating a heart-healthy diet, also may help prevent Alzheimer's disease or delay its onset.

Speeding treatment development

Developing new medications is a slow and painstaking process. The pace can be especially frustrating for individuals with Alzheimer's and their families who are waiting for good news about fresh treatment options. To help accelerate discovery, the Coalition Against Major Diseases (CAMD), an alliance of pharmaceutical companies, nonprofit foundations and government advisers, have forged a first-of-its-kind partnership to share data from Alzheimer's clinical trials in which the experimental treatments didn't work as hoped. Researchers anticipate that sharing these data from more than 4,000 study participants will speed development of more effective therapies.

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