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AD Clinical Trials: Questions & Answers


Participating in a Clinical Trial

Rapid advances in our knowledge about AD have led to the development of many new drugs and treatment strategies. However, before these new strategies can be adopted, they must be shown to work in patients. This means that clinical trials - studies in people to rigorously test how well a treatment works - have become an increasingly important part of AD research. Advances in treatment are only possible through the participation of patients and family members in clinical trials.

Clinical trials are the primary way that researchers find out if a promising treatment is safe and effective for patients. Clinical trials also tell researchers which treatments are more effective than others. Trials take place at private research facilities, teaching hospitals, specialized AD research centers, and doctors' offices.

Participating in a clinical trial is a big step for people with AD and their caregivers. That's why physicians and clinical trials staff spend lots of time talking with participants about what it's like to be in a trial and the pros and cons of participating. Here are some things that potential participants might want to know about clinical trials.

What kind of trials are there?

-Treatment trials with existing drugs assess whether an already approved drug or compound is useful for other purposes. For example, one current trial is testing whether anti-inflammatory drugs already used to treat arthritis might help to prevent AD.

-Treatment trials with experimental drugs or strategies find out whether a brand new drug or treatment strategy can help improve cognitive function or lessen symptoms in people with AD, slow the progression to AD, or prevent it. Potential drugs tested in these trials are developed from knowledge about the mechanisms involved in the AD disease process. These compounds are rigorously tested in tissue culture and in animals for their action. Safety and effectiveness studies are also conducted in animals before the compounds are tested in humans.

What are the phases of clinical trials?

-During Phase I trials, a study team gives the treatment to a small number of volunteers and examines its action in the body, its safety, and its effects at various doses. Phase I trials generally last only a few months.

-If results show that the treatment appears safe, it will be tested in Phase II and Phase III clinical trials. These trials involve larger numbers of people over longer periods of time. In these trials, the study team wants to know whether the treatment is safe and effective and what side effects it might have.

After these phases are complete and investigators are satisfied that the treatment is safe and effective, the study team may submit its data to the Food and Drug Administration (FDA) for approval. The FDA reviews the data and decides whether to approve the drug or treatment for use in patients.

What happens when a person signs up for a clinical trial?

First it is important to learn about the study. Study staff explain the trial in detail to potential research participants and describe possible risks and benefits. Staff also talk about the participants' rights as research volunteers, including their right to leave the study at any time. Participants and their family members are entitled to have this information repeated and explained until they feel they understand the nature of the study and any potential risks.

Once all questions have been answered and if there is still interest in being a part of the study, a patient participant is asked to sign an informed consent form. Laws and regulations regarding informed consent differ across States and research institutions, but all are intended to ensure that patient participants are protected and well cared for.

In some cases, a patient participant may no longer be able to provide informed consent because of problems with memory and confusion. In such cases, it is still possible for an authorized representative (usually a family member) to give permission for the patient to participate. For example, the patient participant may have previously included research participation as part of his or her durable power of attorney.

The person (proxy) exercising the durable power of attorney can decide to let the patient participate in a trial if they are convinced that the patient would have wanted to consent if able to do so. Even so, it is still important that patients assent to be in the study, even if they can no longer formally consent to it. Different States have different laws about who is a legal representative. These laws are in a state of flux as researchers and the public grapple with the ethical issues of proxy consent.

Next, patients go through a screening process to see if they qualify to participate in the study. If they qualify and can safely participate, they can proceed with the other parts of the study.

What happens during a trial?

If participants agree to join the study and the screening process shows they're a good match, they have a "baseline" visit with the study staff. This visit generally involves a full physical exam and extensive cognitive and physical tests. This give the study team information against which to measure future mental and physical changes. Participants also receive the test drug or treatment. As the study progresses, participating patients and family members usually must follow strict medication or treatment instructions and keep detailed records of symptoms.

Every so often, participants visit the clinic or research center to have physical and cognitive exams, give blood and urine samples, and talk with study staff. These visits allow the investigators to assess the effects of the test drug or treatment, see how the disease is progressing, and see how the participant and the caregiver are doing.

In most clinical trials, participants are randomly assigned to a study group. One group, the test group, receives the experimental drug. Other groups may receive a different drug or a placebo (an inactive substance that looks like the study drug). Having the different groups is important because only by comparing them can researchers be confident that changes in the test group are the result of the experimental treatment and not some other factor.

In many trials, no one - not even the study team - knows who is getting the experimental drug and who is getting the placebo or other drug. This is called "masking" meaning that the patient/family member and the staff are "blind" to the treatment being received.

What should people consider before participating in a clinical trial?

Expectations and motivations. Clinical trials generally don't have miraculous results. The test drug or treatment may relieve a symptom, change a clinical measurement, or reduce the risk of death. With a complex disease like AD, it is unlikely that one drug will cure or prevent the disease. Some people choose not to participate or drop out of a study because this reality doesn't meet their expectations. Others [NF1]participate because they realize that even if the benefit to them may be slight, they are making a valuable contribution to knowledge that will help future patients.

Uncertainty. Some families have a hard time with the uncertainties of participation - not knowing whether the person is on the test drug or the placebo, not being able to choose which study group to be in, not knowing for a long time whether the study was successful or not. Ongoing and open communication with study staff can help to counter this frustration.

Finding the right clinical trial. Some clinical trials want participants who are cognitively healthy or have only mild symptoms because they are testing a drug that might delay the decline in cognitive function. Other trials are interested in working with participants who have more advanced AD because they are testing a drug that might lessen behavioral symptoms, or they are testing new strategies to help caregivers. Even though a participant may not be eligible for one trial, another trial may be just right.

The biggest benefit of all. Many families find that the biggest benefit of participating in a clinical trial is the regular contact with the study team. These visits provide an opportunity to get state-of-the-art AD care and also to talk on an ongoing basis with experts in AD who have lots of practical experience and a broad perspective on the disease. The study team understands and can provide advice on the emotional and physical aspects of the person with AD and the caregivers' experience. They can suggest ways to cope with the present and give insights into what to expect in the future. They also can share information about support groups and other helpful resources.

For more information

For a list of clinical trials on Alzheimer's disease and dementia currently in progress at centers throughout the U.S., go to the ADEAR Clinical Trials Database.

You may also wish to visit these clinical trials websites:

National Institutes of Health www.clinicaltrials.gov

Alzheimer's Association www.alz.org/Resources/FactSheets.asp

 

Adapted from: Alzheimer's Disease: Unraveling the Mystery, 2002.




Page last updated Nov 19, 2008

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