What are Clinical Trials?
Clinical trials are research studies in which patients may volunteer to take part. Phoenix Children’s Hospital uses clinical trials to find better ways to prevent, diagnose and treat childhood diseases and injuries. Doctors use treatment trials to learn more about how to fight cancer, cardiovascular, endocrine and neurological disease. This guide is for patients who may join a treatment trial. Clinical trials are part of a long, careful process, which may take many years. First, doctors study a new treatment in the lab. Then they often study the treatment in animals. If a new treatment shows promise, doctors then test the treatment in people. Doctors do this in three to four steps, or phases described below. Your doctor may offer you a clinical trial as a treatment option.
How am I Protected?
Phoenix Children’s Hospital’s most important job is to protect patients.
First, PCH protects patients in clinical trials by following well-planned protocols.
- Explains the treatment plan.
- Lists the medical tests patients will receive.
- Gives the number of how many patients will take part in the clinical trial.
- Lists eligibility criteria, which are guidelines to decide who may join the clinical trial.
- Explains safety information.
Second, PCH protects patients by using a careful informed consent process.
Third, our Institutional Review Boards (IRBs) protect patients by reviewing protocols and monitoring trials. The IRBs are committees of doctors, nurses, chaplains, social workers, lawyers and community members. They make sure that trials follow federal laws and that patients are protected.
The U.S. Food and Drug Administration (FDA) audits the IRBs’ files. Also, FDA officials may visit PCH at any time and review anything they choose related to clinical trials.
What are the Phases of Clinical Trials?
A new treatment goes through several phases. Each phase has a different purpose:
- Phase I trials test if a new treatment is safe and look for the best way to give the treatment. Doctors also look for signs that cancer responds to the new treatment.
- Phase II trials test if one type of cancer responds to the new treatment.
- Phase III trials test if a new treatment is better than a standard treatment.
- Phase IV trials find more information about long-term benefits and side effects.
Most of the time, when you take part in a clinical trial, you will only be in that one phase of the study. Treatments move through the phases, but patients do not.
Phase I Trials - Test if a new treatment is safe in people. Doctors also find the best way to give the treatment.
The goal of a Phase I trial is to:
- Find out if a new treatment is safe.
- Find the best way to give the new treatment, such as by mouth or by vein.
- See if there are signs that cancer responds to the new treatment.
Phase I trials usually include 15 to 30 patients who are divided into small groups. These groups are called cohorts. The first cohort receives a dose of the new drug. Doctors may collect blood or urine samples to measure drug levels in the patients.
If the first cohort does not have any severe side effects, then a new cohort receives a higher dose of the same drug. The dose increases with each new cohort until the doctors find the best dose for future testing. With each increasing dose, doctors test each patient to see if he or she is responding to the treatment. If the doctors find that the treatment is safe, then it will move forward to be studied in a Phase II trial.
Phase II Trials - Test if a new treatment works for the disease or condition being studied.
Fewer than 100 patients usually join a Phase II trial. Even though the main goal is to see if the treatment works, doctors still closely watch patients’ side effects. If the new treatment works, doctors may go on to study it in a Phase III trial.
Phase III Trials - Test if a new treatment is better than standard treatment.
Phase III trials may include hundreds to thousands of patients around the country or world. Each patient enrolled in a Phase III clinical trial has a chance of being in one of the following groups:
- Control group – The group that gets the standard treatment.
- Study group – The group that gets the new treatment being tested.
Doctors do not know if the new treatment is better than the standard treatment, but they believe it is as good and may be better.
How are patients put into groups?
A computer decides which patients are in the control group and which patients are in the study group. Patients have a chance of being in either group. The patient and doctor do not decide. It is random and due to chance alone. This helps to avoid bias in the clinical trial. (Bias happens when human choices affect a study’s results.)
Would my doctor know which group I am in?
In single blind studies, patients do not know whether they are in the control or study group, but the doctor does. In double blind studies, neither the patients nor the doctors know which patients are in each group. (In case of an emergency, doctors can find this information in the study file.)
Would I be given a placebo?
A placebo is something that looks like medicine, but is not. If a placebo is used, it is given together with the best standard treatment. This allows doctors to compare standard treatment alone to standard treatment with a new drug. If there isn’t a standard treatment, then the placebo may be given alone, but in cancer trials this is not common.
After the Phase III trial, the FDA reviews the clinical trial results to make sure the treatment is safe and effective for people to use. The FDA decides whether to approve the treatment so that it is available for all patients.
Phase IV Trials - Find more information about long-term side effects.
In Phase IV trials, doctors study treatments that the FDA has already approved. The goal of Phase IV trials is to continue studying side effects of a new treatment.