Clinical Trials Explained

Continued progress in the treatment and cure rates of childhood cancer depends on identifying and testing new drugs in carefully conducted clinical trials. New drugs and treatments are constantly being developed. Before any new drug can be evaluated in children, it has usually already been studied in the laboratory and on adults and has been deemed potentially safe for use in children.

There are four levels of clinical trials.

• The first studies on children, after laboratory studies and adult studies have rendered them potentially safe and potentially effective, are called Phase I (Phase 1) trials. The purpose of a Phase I trial is to determine what the safest and highest dose of an experimental drug is in children. Clinical trials can also determine if there are any side effects of experimental drugs, monitor how the drug works in a child’s body (called pharmacokinetics), and determine what supportive care a child needs with the administration of the experimental drug. This defines an experimental treatment using the drug. Since the drug is new and unproven, your child may not be helped by entering a Phase I study, but the information learned from Phase I studies may help other children in the future.
• A Phase II (Phase 2) study explores how different tumors respond to the experimental treatment.
• A Phase III (Phase 3) study compares a standard therapy with the experimental treatment using the drug.
• When a study reaches Phase IV (Phase 4), the treatment and the drug have already been approved. Phase IV studies provide a large database from which to consider further medical use.