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Clinical trials are conducted in a healthcare setting
(a hospital or clinic) and are typically monitored by a trained
healthcare professional. An Institutional Review Board or IRB
approves all clinical trials. This is a committee made up of
doctors, ethicists, and members of the general public and
administrators. This group is held responsible for agreeing that a
trial does not represent an unreasonable risk to patients who are
participating. Trials are also reviewed by the FDA. Your doctor is
responsible for your well being and is the best person to decide
whether or not you are eligible to participate in a trial. Whenever
you agree to enter a trial you are given the name and telephone
number of a contact in your local physician's office who will answer
your questions as well as a member of the IRB whom you can contact
if you have any doubts. |
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There are many reasons people take part in research
studies. Often it gives you a chance to access a medicine that is
not available on the market for prescription. If this is the case
you should remember that the study is being performed to find out if
the drug works and if it is safe. This means that there is some
information that is unknown about the drug and it is considered
experimental. Often the process of collecting information in the
study will allow your doctor to find out more about your disease and
the effects it has on you. This may allow you to benefit from better
treatment after you have completed a trial. A trial may not benefit
you directly, but the information gathered may be of help to other
patients with the same condition. Many patients derive satisfaction
from knowing that they are part of the effort to potentially reduce
the suffering of other people. |
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You can find out about clinical trials from many
sources. There are often advertisements in your doctor's office.
Many clinical trials are posted on Internet pages such as this one
and provide an excellent source of information. Each trial has
certain requirements for participation. Your doctor will take a
medical history from you and may request additional testing to
determine if you are eligible according to the criteria for the
study. |
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Anyone entering a clinical trial in the United States
is required to sign a form indicating that they understand what will
happen to them during the study. If the patient is a child, a parent
or guardian must sign the form. This form will tell you what
treatment will be given, what kind of problems might occur, and what
other treatments might work for your condition. The amount of help
expected from the study will be given. In phase I studies, it is
usually not known whether any help will occur. The informed consent
form also indicates which costs are covered by the study and which
must be paid by you (or your insurance). |
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A board consisting of health care professionals from
the institution where the clinical trial takes place, as well as
members of the local community. The board scrutinizes all trial
activities including recruitment, advertising, and potential risks.
The IRB also makes sure that FDA regulations are being followed in a
particular trial. |
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A protocol is a written procedure describing, in
detail, the steps to conduct a controlled study (usually a
preclinical study or clinical trial) to ensure the collection of
valid data. |
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Most clinical trials are carried out in steps called
phases. Each phase is designed to find different information.
Patients may be eligible for studies in different phases depending
on their general condition, the type and stage of their condition,
and what therapy, if any, they have already had. Patients are seen
regularly to determine the effect of the treatment, and treatment is
always stopped if side effects become too severe. (Please continue
for a description of each of the four phases involved in a clinical
trial.) |
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Phase I studies are primarily concerned with
assessing the drug's safety. This initial phase of testing in humans
is done in a small number of healthy volunteers (20 to 100), who are
usually paid for participating in the study. The study is designed
to determine what happens to the drug in the human body--how it is
absorbed, metabolized, and excreted. A phase I study will
investigate side effects that occur as dosage levels are increased.
This initial phase of testing typically takes several months. About
70 percent of experimental drugs pass this initial phase of testing. |
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Once a drug has been shown to be safe, it must be
tested for effectiveness. This second phase of testing may last from
several months to two years and involve up to several hundred
patients. Most phase II studies are randomized trials. One group of
patients will receive the experimental drug while a second
"control" group will receive a standard treatment or
placebo. Often these studies are "blinded"--neither the
patients nor the researchers know who is getting the experimental
drug. In this manner, the study can provide the pharmaceutical
company and the FDA comparative information about the relative
safety of the new drug and its effectiveness. Only about one-third
of experimental drugs successfully complete both phase I and phase
II studies. Safety continues to be evaluated. |
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In a phase III study, a drug is tested in several
hundred to several thousand patients. This large-scale testing
provides the pharmaceutical company and the FDA with a more thorough
understanding of the drug's safety, effectiveness, benefits, and the
range of possible adverse reactions. Most phase III studies are
randomized and blinded trials. Phase III studies typically last
several years. Seventy to 90 percent of drugs that enter phase III
studies successfully complete this phase of testing. Once a phase
III study is successfully completed, a pharmaceutical company can
request FDA approval for marketing the drug. |
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In late phase III/phase IV studies, pharmaceutical
companies have several objectives: (1) studies often compare a drug
with other drugs already in the market; (2) studies are often
designed to monitor a drug's long-term safety, effectiveness and
impact on a patient's quality of life; and (3) many studies are
designed to determine the cost-effectiveness of a drug therapy
relative to other traditional and new therapies. |
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