Alzheimer's treatments: What's on the horizon?
Despite many promising leads, new treatments for Alzheimer's are slow to emerge.By Mayo Clinic Staff
Current Alzheimer's treatments temporarily improve symptoms of memory loss and problems with thinking and reasoning.
These Alzheimer's treatments boost performance of chemicals in the brain that carry information from one brain cell to another. However, these treatments don't stop the underlying decline and death of brain cells. As more cells die, Alzheimer's disease continues to progress.
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 basic disease processes.
Future Alzheimer's treatments may include a combination of medications, similar to how treatments for many cancers or HIV/AIDS include more than a single compound.
The following treatment options are among the strategies currently being studied.
Taking aim at plaques
Some of the new Alzheimer's treatments in development target microscopic clumps of the protein beta-amyloid (plaques). Plaques are a characteristic sign of Alzheimer's disease.
Strategies aimed at beta-amyloid include:
Recruiting the immune system. Several drugs — known as monoclonal antibodies — may prevent beta-amyloid from clumping into plaques and help the body clear the beta-amyloid from the brain. Monoclonal antibodies mimic the antibodies your body naturally produces as part of your immune system's response to foreign invaders or vaccines.
Recent research on the monoclonal antibody solanezumab found a possible benefit for people with mild Alzheimer's disease. The drug appeared to be more effective when it was given earlier in the course of the disease. The drug seemed safe in the most recent research. Further studies are in the works.
Aducanumab is another drug that has shown promise in preliminary studies. More studies are underway for this treatment.
Preventing destruction. Several years ago, researchers learned that beta-amyloid interacts with another protein called Fyn. When combined with beta-amyloid, Fyn is over-activated, which triggers a destruction of connections between nerve cells (synapses) in the brain.
A drug initially developed as a possible cancer treatment — saracatinib — is now being tested in Alzheimer's disease.
In mice, the drug turned off Fyn, which allowed synapses to start working again and the animals experienced a reversal of some memory loss. A human trial is now underway.
Production blockers. These therapies 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 different enzymes.
Several experimental drugs aim to block the activity of these enzymes. They're known as beta- and gamma-secretase inhibitors.
Keeping tau from tangling
A vital brain cell transport system collapses when a protein called tau twists into microscopic fibers called tangles, which are another common brain abnormality of Alzheimer's. Researchers are looking at a way to prevent tau from forming tangles.
Tau aggregation inhibitors and tau vaccines are currently being studied in clinical trials.
Alzheimer's causes chronic, low-level brain cell inflammation. Researchers are studying ways to treat inflammatory processes at work in Alzheimer's disease.
Researchers are also studying the diabetes drug pioglitazone (Actos) because it may lessen beta-amyloid and inflammation in the brain.
Feb. 26, 2016
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