Treatment trials are carefully designed research studies in which volunteers test new breast cancer treatments.
Clinical trials are also referred to as clinical studies, medical research, and research protocols. Carefully conducted clinical trials provide the information necessary for the US Food and Drug Administration (FDA) to determine if and when new breast cancer treatments should be approved for use as routine care.
Clinical trials for new breast cancer treatments are a very regulated process. They can only get underway after there is evidence from laboratory studies (first in cells and then in animals, like mice) that the treatment appears to work. Clinical trials that are investigating drugs that have been used for other types of cancer or other diseases, or that are using approved cancer drugs in new combinations, can also start as laboratory studies and are also very regulated.
Before a trial begins, the researchers develop a detailed plan, called a study protocol, which explains the goals for the trial and how it will take place. In breast cancer treatment trials, participants are assigned to a specific group that will receive a specific treatment. The researchers then follow the study participants for weeks, months, or even years to assess the safety and effectiveness of the new treatment.
Clinical trials are conducted in a series of steps, called phases:
Phase I: These trials test an investigational treatment in a small group of people (20-80) for the first time. They are designed to evaluate a drug's safety and identify side effects. They also determine how a drug should be given (by mouth, injected into the blood, or injected into the muscle), how often, and the proper dosage range. In a Phase I trial all patients receive the investigational treatment.
Phase II: These trials take place after Phase I trials have established safety and a proper dosage (or dosage range) and method of use for the experimental treatment. They enroll a larger number of people (usually between 50 - 300) than Phase I studies, and are designed to further evaluate safety and effectiveness. In a Phase II trial all patients typically receive the investigational treatment.
Phase III: These trials test the investigational treatment the Phase II trials have found to be effective by comparing it to the current standard of care in a large group of people (100-3,000). This allows the researchers to confirm effectiveness, monitor side effects, and collect additional information about the investigational treatment in a large number of people. Phase III trials may be conducted at many doctors' offices, clinics, and cancer centers nationwide. In Phase III trials patients are assigned randomly, like flipping a coin, to an investigational treatment group or a standard of care group.
Phase IV: These trials further evaluate new uses or long-term effects of the treatment after it has received FDA approval.
What Are Clinical Trial Phases?: This video from the National Cancer Insitute presents a very easy-to-follow description of clinical trial phases.