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An Introduction to Clinical Trials
Choosing to participate in a clinical trial is
an important personal decision. The following frequently asked questions provide
detailed information about clinical trials. In addition, it is often helpful to
talk to a physician, family members, or friends about deciding to join a trial.
After identifying some trial options, the next step is to contact the study
research staff and ask questions about specific trials.
What is a clinical trial?
A clinical trial (also clinical research) is a
research study in human volunteers to answer specific health questions.
Carefully conducted clinical trials are the fastest and safest way to find
treatments that work in people and ways to improve health. Interventional trials
determine whether experimental treatments or new ways of using known therapies
are safe and effective under controlled environments. Observational trials
address health issues in large groups of people or populations in natural
settings.
Why participate in a clinical
trial?
Participants in clinical
trials can play a more active role in their own health care, gain access to new
research treatments before they are widely available, and help others by
contributing to medical research.
Who can participate in a
clinical trial?
All clinical
trials have guidelines about who can participate. Using
inclusion/exclusion criteria is an important principle of medical research
that helps to produce reliable results. The factors that allow someone to
participate in a clinical trial are called "inclusion criteria" and those that
disallow someone from participating are called "exclusion criteria". These
criteria are based on such factors as age, gender, the type and stage of a
disease, previous treatment history, and other medical conditions. Before
joining a clinical trial, a participant must qualify for the study. Some
research studies seek participants with illnesses or conditions to be studied in
the clinical trial, while others need healthy participants. It is important to
note that inclusion and exclusion criteria are not used to reject people
personally. Instead, the criteria are used to identify appropriate participants
and keep them safe. The criteria help ensure that researchers will be able to
answer the questions they plan to study.
What happens during a
clinical trial?
The clinical trial process depends
on the kind of trial being conducted (See What are the
different types of clinical trials?) The clinical trial team includes
doctors and nurses as well as social workers and other health care
professionals. They check the health of the participant at the beginning of the
trial, give specific instructions for participating in the trial, monitor the
participant carefully during the trial, and stay in touch after the trial is
completed.
Some clinical trials involve more tests and
doctor visits than the participant would normally have for an illness or
condition. For all types of trials, the participant works with a research team.
Clinical trial participation is most successful when the
protocol
is carefully followed and there is frequent contact with the research staff.
What is informed consent?
Informed consent is the process of
learning the key facts about a clinical trial before deciding whether or not to
participate. It is also a continuing process throughout the study to provide
information for participants. To help someone decide whether or not to
participate, the doctors and nurses involved in the trial explain the details of
the study. If the participant's native language is not English, translation
assistance can be provided. Then the research team provides an
informed consent
document that includes details about the study, such as its purpose,
duration, required procedures, and key contacts. Risks and potential benefits
are explained in the informed consent document. The participant then decides
whether or not to sign the document. Informed consent is not a contract, and the
participant may withdraw from the trial at any time.
What are the benefits and risks of
participating in a clinical trial?
Benefits:
Clinical trials that are well-designed and
well-executed are the best approach for eligible participants to:
- Play an active role in their own health
care.
- Gain access to new research treatments
before they are widely available.
- Obtain expert medical care at leading
health care facilities during the trial.
- Help others by contributing to medical
research.
Risks:
There are risks to clinical trials.
- There may be unpleasant, serious or even
life-threatening side effects to experimental treatment.
- The experimental treatment may not be
effective for the participant.
- The
protocol
may require more of their time and attention than would a non-protocol
treatment, including trips to the study site, more treatments, hospital
stays or complex dosage requirements.
What are side effects and adverse
reactions?
Side effects are any undesired
actions or effects of the experimental drug or treatment. Negative or adverse
effects may include headache, nausea, hair loss, skin irritation, or other
physical problems. Experimental treatments must be evaluated for both immediate
and long-term side effects.
How is the safety of the
participant protected?
The ethical and legal codes that
govern medical practice also apply to clinical trials. In addition, most
clinical research is federally regulated with built in safeguards to protect the
participants. The trial follows a carefully controlled protocol, a study plan
which details what researchers will do in the study. As a clinical trial
progresses, researchers report the results of the trial at scientific meetings,
to medical journals, and to various government agencies. Individual
participants' names will remain secret and will not be mentioned in these
reports (See
Confidentiality Regarding Trial Participants).
What should people consider
before participating in a trial?
People should know as much as
possible about the clinical trial and feel comfortable asking the members of the
health care team questions about it, the care expected while in a trial, and the
cost of the trial. The following questions might be helpful for the participant
to discuss with the health care team. Some of the answers to these questions are
found in the informed consent document.
- What is the purpose of the study?
- Who is going to be in the study?
- Why do researchers believe the
experimental treatment being tested may be effective? Has it been tested
before?
- What kinds of tests and experimental
treatments are involved?
- How do the possible risks, side effects,
and benefits in the study compare with my current treatment?
- How might this trial affect my daily life?
- How long will the trial last?
- Will hospitalization be required?
- Who will pay for the experimental
treatment?
- Will I be reimbursed for other expenses?
- What type of long-term follow up care is
part of this study?
- How will I know that the experimental
treatment is working? Will results of the trials be provided to me?
- Who will be in charge of my care?
What kind of preparation
should a potential participant make for the meeting with the research
coordinator or doctor?
- Plan ahead and write down possible
questions to ask.
- Ask a friend or relative to come along for
support and to hear the responses to the questions.
- Bring a tape recorder to record the
discussion to replay later.
Every clinical trial in the U.S. must be
approved and monitored by an
Institutional Review Board
(IRB) to make sure the risks are as low as
possible and are worth any potential benefits. An IRB is an independent
committee of physicians, statisticians, community advocates, and others that
ensures that a clinical trial is ethical and the rights of study participants
are protected. All institutions that conduct or support biomedical research
involving people must, by federal regulation, have an IRB that initially
approves and periodically reviews the research.
Does a participant continue to
work with a primary health care provider while in a trial?
Yes. Most clinical trials provide
short-term treatments related to a designated illness or condition, but do not
provide extended or complete primary health care. In addition, by having the
health care provider work with the research team, the participant can ensure
that other medications or treatments will not conflict with the
protocol.
Can a participant leave a
clinical trial after it has begun?
Yes. A participant can leave a
clinical trial, at any time. When withdrawing from the trial, the participant
should let the research team know about it, and the reasons for leaving the
study.
Where do the ideas for trials
come from?
Ideas for clinical trials usually
come from researchers. After researchers test new therapies or procedures in the
laboratory and in animal studies, the experimental treatments with the most
promising laboratory results are moved into clinical trials. During a trial,
more and more information is gained about a experimental treatment, its risks
and how well it may or may not work.
Who sponsors clinical trials?
Clinical trials are sponsored or
funded by a variety of organizations or individuals such as physicians, medical
institutions, foundations, voluntary groups, and pharmaceutical companies, in
addition to federal agencies such as the National Institutes of Health (NIH),
the Department of Defense (DOD), and the Department of Veteran's Affairs (VA).
Trials can take place in a variety of locations, such as hospitals,
universities, doctors' offices, or community clinics.
What is a protocol?
A protocol is a study plan on
which all clinical trials are based. The plan is carefully designed to safeguard
the health of the participants as well as answer specific research questions. A
protocol describes what types of people may participate in the trial; the
schedule of tests, procedures, medications, and dosages; and the length of the
study. While in a clinical trial, participants following a protocol are seen
regularly by the research staff to monitor their health and to determine the
safety and effectiveness of their treatment.
What is a placebo?
A placebo is an inactive pill,
liquid, or powder that has no treatment value. In clinical trials, experimental
treatments are often compared with placebos to assess the experimental
treatment's effectiveness. In some studies, the participants in the
control group
will receive a placebo instead of an active drug or experimental treatment.
What is a control or control
group?
A control is the standard by which
experimental observations are evaluated. In many clinical trials, one group of
patients will be given an experimental drug or treatment, while the control
group is given either a standard treatment for the illness or a placebo.
What are the different types of
clinical trials?
-
Treatment
trials test experimental treatments, new combinations of drugs, or new
approaches to surgery or radiation therapy.
-
Prevention
trials look for better ways to prevent disease in people who have never had
the disease or to prevent a disease from returning. These approaches may include
medicines, vitamins, vaccines, minerals, or lifestyle changes.
-
Diagnostic
trials are conducted to find better tests or procedures for diagnosing a
particular disease or condition.
-
Screening
trials test the best way to detect certain diseases or health conditions.
-
Quality of Life
trials (or Supportive Care trials) explore ways to improve comfort and the
quality of life for individuals with a chronic illness.
What are the phases of
clinical trials?
Clinical trials are conducted in
phases. The trials at each phase have a different purpose and help scientists
answer different questions:
- In
Phase I trials,
researchers test a 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.
- In
Phase II trials,
the experimental study drug or treatment is given to a larger group of people
(100-300) to see if it is effective and to further evaluate its safety.
- In
Phase III
trials, the experimental study drug or treatment is given to large groups of
people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare
it to commonly used treatments, and collect information that will allow the
experimental drug or treatment to be used safely.
- In
Phase IV trials,
post marketing studies delineate additional information including the drug's
risks, benefits, and optimal use.
What is an "expanded access"
protocol?
Most human use of
investigational new drugs takes place in
controlled
clinical trials conducted to assess safety and
efficacy
of new drugs. Data from the trials can serve as the basis for the drug marketing
application. Sometimes, patients do not qualify for these carefully-controlled
trials because of other health problems, age, or other factors. For patients who
may benefit from the drug use but don't qualify for the trials,
FDA
regulations enable manufacturers of investigational new drugs to provide for
"expanded access" use of the drug. For example, a
treatment IND
(Investigational New Drug application) or treatment protocol is a relatively
unrestricted study. The primary intent of a treatment IND/protocol is to provide
for access to the new drug for people with a life-threatening or serious disease
for which there is no good alternative treatment. A secondary purpose for a
treatment IND/protocol is to generate additional information about the drug,
especially its safety. Expanded access protocols can be undertaken only if
clinical investigators are actively studying the experimental treatment in
well-controlled studies, or all studies have been completed. There must be
evidence that the drug may be an effective treatment in patients like those to
be treated under the protocol. The drug cannot expose patients to unreasonable
risks given the severity of the disease to be treated.
Some investigational drugs are available from
pharmaceutical manufacturers through expanded access programs listed in
ClinicalTrials.gov. Expanded access
protocols are generally managed by the manufacturer, with the investigational
treatment administered by researchers or doctors in office-based practice. If
you or a loved one are interested in treatment with an investigational drug
under an expanded access protocol listed in
ClinicalTrials.gov, review the protocol
eligibility
criteria and location information and inquire at the Contact Information
number.
_____________
Resources:
"An Introduction To Clinical
Trials."
ClinicalTrials.gov.
© Teri Robert, July 7, 2006
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