 When
your child is diagnosed with cancer,
it is important to know all of the
treatment options available in order
to make the best decision. This may
include clinical
trials, which are research
studies designed to evaluate new cancer
treatment options. Clinical trials
test the safety and effectiveness
of treatments, many of which are only
available through participating in
a clinical trial. Trials evaluate
new anti-cancer drugs, unique approaches
to surgery and radiation therapy,
and new combinations of treatments.
In the United States, the Food and
Drug Administration (FDA) oversees
the conduct of clinical trials.
Are
all clinical trials the same?
Development
of new anticancer drugs 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
to 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. Phase
I therapy may produce anti-cancer
effects and a small number of patients
may benefit, however, the primary
goals of this phase are to determine
safety issues, which include:
•
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.
Phase
I trials usually involve a small
number of patients for whom other
standard therapies have failed or
no known alternative therapy is
available. Upon completion of phase
I trials, the information that has
been gathered is used to begin phase
II trials.
Phase
II 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 phase I. These trials
usually require a slightly higher
number of patients than phase I
trials. In general, all of the patients
participating in a phase II trial
will receive the treatment that
is being investigated. 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 III 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 III trials
require a large number of patients
to measure the statistical validity
of the results because patient age,
sex, race, and other unknown factors
could affect the results. To obtain
an adequate number of patients,
several physicians (investigators)
from different institutions typically
participate in phase III clinical
trials.
Phase
IV Trials:
Once the drug or treatment
is approved and 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 usefulness in
different types of cancers.
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