Interventional clinical trials that study new treatments often have phases. Early Phase 1 trials test if the new treatment affects the body and how. Phase 1  trials test the treatment’s side effects, how it is put into the body, and the timing. They also determine the maximum amount of medicine to give, while keeping the side effects acceptable for participants. Phase 2  trials test whether the treatment works for a certain cancer type or other diseases, such as shrinking a tumor or improving blood test results. The most effective treatment dosing and way it was put into the body from Phase 1 are typically used as the starting point. Phase 3  trials test if the new treatment is better than what is currently available, such as which group of patients has better survival rates or fewer side effects. In most cases, treatments move into Phase 3 clinical trials only after they meet the goals of Phase 1 and Phase 2 clinical trials. Phase 4 trials test the treatment side effects over time after it has been approved by the U.S. Food and Drug Administration (FDA) and is available. Depending on the availability, this treatment may be available to those not participating in a clinical trial. For more information, please read CancerCare’s clinical trial guide.