The current treatment options for Alzheimer’s disease (AD) are focused on treating symptoms and not the underlying mechanisms of the disease. This limitation can be very frustrating for patients, caregivers, and physicians. Until recently the pathways associated with Alzheimer’s were uncertain. Scientists and researchers are still working on understanding exactly what causes the plaques and tangles and how to prevent the destruction of brain cells. Numerous biochemical and cellular pathways are involved at some point in the disease process and are being studied as possible targets for medication therapy. When human studies are developed, researchers need participants to determine if their discovery/methods are safe and effective and should be made available to the public. Clinical trials provide an alternative option to currently available therapies.
Clinical trials may focus on prevention, new treatments or new uses for already available treatments, screening or diagnosis methods, or improving quality of life. Clinical trials are conducted in phases. Each phase has a different purpose and helps scientists answer different questions:
Phase I trials: researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. Phase II trials: the experimental study drug or treatment is given to a larger group of people (100-300) to assess its effectiveness and to further evaluate its safety. Phase III trials: the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm effectiveness, monitor side effects, compare it to standard treatments, and collect information that will allow the experimental drug or treatment to be used safely. Phase IV trials: post marketing studies describe additional information including the drug's risks, benefits, and optimal use.
Each clinical trial must develop a plan (protocol) that describes who can participate, what type of screening/tests will be done, medications involved, study timeline, and a hypothesis (suggested outcome). Each participant must meet the eligibility requirements set forth by investigators so the information collected during the study can be accurately interpreted. Common eligibility/exclusion criteria involve age, sex, living arrangements, stage of the disease, current or past medical treatment, or other diseases. These conditions limit the possibility of study results being misinterpreted.
In addition to the researcher’s plan, the Food and Drug Administration also sets rules to protect patients who participate in most clinical trials. An overview of clinical trial regulations can be found on www.fda.gov under the Science and Research, Clinical Trial link. Informed consent is part of this process and should be carefully read and understood before signing. This document will explain details of the study, what risks may be associated, what tests or procedures will be conducted, and contact information. It is not a binding contract; the participant may leave the study at any time. Participating in a clinical trial should be carefully considered and weighed against the risks involved vs. possible benefits. The clinical researchers should provide you with enough information to be comfortable with making an informed decision.
Why consider a clinical trial?
w Standard treatments have failed or were intolerable
w To contribute to the acquisition of medical knowledge
What to consider before participating in a clinical trial?
§ Impact on daily living (timing of treatment, keeping records, follow-up visits)
§ Length of the trial
§ How do you know if the treatment is working? Are results available to participant?
§ Will therapy be available after the trial has ended? (expanded access protocol)
Designed trials are an excellent way for patients to be actively involved in their treatment and receive the attention, expertise, and support of a research team. Participation can provide access to new treatments before they are available to the public. The risks associated with participating in a clinical trial may be that you receive placebo (inactive treatment) instead of the treatment drug or the experimental treatment may not be effective or could cause serious side effects. In a double-blind trial, neither investigators nor participants know who is receiving what treatment. This prevents unintended bias. Some studies compare a new treatment to current standard treatment and do not use a placebo. It is important to know that during any study, you will be monitored by clinicians and can withdraw at any time.
Alzheimer’s Clinical Trials in the Southeast (within 500 miles of Pensacola, Fl)
IVIG- Intravenous immunoglobulin is being studied to evaluate if passive immunization can be successful in reducing amyloid plaques in the brain. This medication is already FDA approved to treat many immune conditions.
Dimebon – An antihistamine used in Russia to treat hay fever. It targets the cell’s mitochondria (energy source). Studies are now in progress in the United States.
RAGE – Receptor for advanced glycation endpoints is a protein thought to bind to amyloid and promote inflammation and nerve cell damage. This study is evaluating effectiveness of a RAGE inhibitor.
NGF – Nerve Growth Factor Study is evaluating if NGF preserves cholinergic neurons and can sustain functioning of brain cells.
Vaccine Trials – New vaccine formulation targets amyloid beta. In 2002 vaccine trials were terminated due to inflammatory complications. Vaccines have been refined to specifically target neurotoxic amyloid without producing this adverse effect.
Several genetic and prevention trials are also underway in the Southeast and can be found by searching the database listed at the end of the article (1).
Latest information on alternative therapies to prevent Alzheimer’s –
Several herbal products have been evaluated for the prevention of AD, based on the theory of decreasing inflammation and preventing cell destruction. These medications are not subject to the same requirements as Food and Drug Administration-approved medications and therefore safety and efficacy may be extremely variable between brands and even lot numbers. Most information currently available is conflicting and does not clearly support the use of these products for the prevention of AD.
Gingko biloba – Gingko evaluation of memory (GEM) study is the largest to date and was conducted over 8 years. The results do not support the use of Gingko biloba for Alzheimer’s prevention.
Vitamin E – an antioxidant, studies have yielded variable results, some positive results when used at high doses with a cholinesterase inhibitor (not recommended in doses > 400 IU /day).
Fish Oil – positive results from animal and observational studies. It is currently being evaluated in a trial by the National Institutes on Aging (risk of bleeding with doses > 3 grams/ day.)
Huperzine – Chinese herb, an acetylcholinesterase inhibitor (like Aricept, Exelon, Razadyne), with antioxidant and neuroprotective qualities. A 2008 Cochrane Review of six trials found the data insufficient support use in AD patients.
Alternative medicines have many drawbacks because the manufacturers are not required to provide the FDA with safety and efficacy data. These drugs are not required to be tested for purity, adverse reactions are not routinely reported, and they could cause unknown interactions with prescription medications. Some companies do their own quality control. Always inform healthcare providers if you are using any non-prescription products, including herbal medications.
For more information on these studies or other Alzheimer’s research
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