 Background
Information on Clinical Research
The
following information is provided by CenterWatch.com
Introduction
Before
a pharmaceutical company can initiate testing in humans, it must conduct extensive
preclinical or laboratory research. This research typically involves years of
experiments in animal and human cells. The compounds are also extensively tested
in animals. If this stage of testing is successful, a pharmaceutical company provides
this data to the Food and Drug Administration (FDA), requesting approval to begin
testing the drug in humans. This is called an Investigational New Drug application
(IND).
How are experimental drugs tested in humans?
The
clinical testing of experimental drugs is normally done in three phases, each
successive phase involving a larger number of people. Once the FDA has granted
a New Drug Approval (NDA), pharmaceutical companies also conduct post marketing
or late phase three/phase four studies. A
Phase One Study:
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. A
Phase Two Study:
Once a drug has been shown to be safe, it must be tested
for efficacy. 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. A
Phase Three Study:
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 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. Post-Marketing
-- Late Phase Three/Phase Four Studies
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 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.
Who pays for clinical research?
Funding for clinical
research comes from both the federal government (through the National Institutes
of Health) and private industry (pharmaceutical and biotech companies). The sponsor
of the research hires physicians, who may work in a wide variety of health-care
settings, to conduct the clinical trial. Physicians are typically paid on a per-patient
basis. The medical care is often provided free to the patient. Patients may also
be paid a small fee to participate in a clinical trial. Should
you participate in clinical research?
People participate in clinical research
for a variety of reasons. People who volunteer for phase II and phase III trials
can gain access to promising drugs long before these compounds are approved for
the marketplace. They typically will get excellent care from the physicians during
the course of the study. This care also may be free. The
patient's rights and safety are protected in two important ways. First, any physician
awarded a research grant by a pharmaceutical company or the NIH must obtain approval
to conduct the study from an Institutional Review Board. The review board, which
is usually composed of physicians and lay people, is charged with examining the
study's protocol to ensure that the patient's rights are protected, and that the
study does not present an undue or unnecessary risk to the patient. Second, anyone
participating in a clinical trial in the United States is required to sign an
"informed consent" form. This form details the nature of the study,
the risks involved, and what may happen to a patient in the study. The informed
consent tells patients that they have a right to leave the study at any time.
Patients
considering participating in clinical research should talk about it with their
physicians and medical caregivers. They also should seek to understand the credentials
and experience of the individuals and the facility involved in conducting the
study. Other
questions to ask include: - How
long will the trial last?
- Where
is the trial being conducted?
- What
treatments will be used and how?
- What
is the main purpose of the trial?
- How
will patient safety be monitored?
- Are
there any risks involved?
- What
are the possible benefits?
- What
are the alternative treatments besides the one being tested in the trial?
- Who
is sponsoring the trial?
- Do
I have to pay for any part of the trial?
- What
happens if I am harmed by the trial?
- Can
I opt to remain on this treatment, even after termination of the trial?
Where can you get more information about clinical research?
The
National Institutes of Health provides detailed information for patients considering
participating in a clinical trial on their web site in the section entitled "An
Introduction to Clinical Trials." | 
