Anatomy of a Clinical Trial
PHASES OF CLINICAL TRIALS
Development of new anticancer agents and treatment strategies occurs
in four phases. Each phase is designed to determine specific information
about the potential new treatment, such as its risks, safety and effectiveness
compared with standard therapy. The hope is that the new therapy will
be an improvement over the previous standard therapy.
Phase I Trials:
This phase is probably the most important step in the development of
a new drug or
therapy. The primary goals of this phase are to determine anticancer
activity in humans,
the maximum tolerated dose of the treatment, the manner in which the
drug works in the
body, the toxic side effects related to different doses and whether toxic
side effects are
reversible. Upon completion of phase I trials, the information that has
been gathered is
used to begin phase II trials.
Phase II Trials:
Once the information is gathered and analyzed from phase I trials, phase II trials
are designed to determine the effectiveness of the treatment in a specific
patient population at the dose and schedules determined in
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Clinical
Trial Links:
National Cancer Institute
Coalition of Cancer Cooperatives Groups
CenterWatch - Clinical Trials Listing Service
Caring4Cancer about
Clinical Trials
phase I. Drugs or therapies that are shown to be active in phase II
trials may become standard treatment or be further evaluated for effectiveness
in phase III trials.
Phase III Trials:
Phase Ill trials compare a new drug or therapy with a standard therapy
in a randomized and controlled manner in order to determine proof of
effectiveness.
Phase IV Trials:
Once the drug or treatment becomes part of standard therapy, the manufacturer
of the drug may elect to initiate phase IV trials. This phase includes
continued evaluation of the treatment effectiveness and monitoring
of side effects as well as implementing studies to evaluate the usefulness
of treatments for different types of cancers. |