Phases of a Clinical Trial

Testing new cancer treatments in clinical trials involve a series of steps, called phases. Clinical trial phases proceed to the next phase once a new treatment is successful.

View a larger image of the phases of a clinical trial

Pre-clinical phase

Preclinical phase is the early discovery and ongoing research conducted by researchers.

Phase 1

Phase 1 clinical trials are first-time tests of treatments on human patients with the purpose to find a safe dose, decide how the new treatment should be given (by mouth, in a vein, etc.) and to see how the new treatment affects the human body and fights cancer.

Phase 2

Phase 2 clinical trials begin once an appropriate dosage of the drug is defined through Phase I trials. In this stage of testing, researchers determine the treatments effectiveness in treating a specific kind and stage of cancer and to see how the new treatment affects the body and fights the cancer.

Phase 3

Phase 3 clinical trials test therapies that have proven to be effective in the first two stages of testing. Researchers compare the new treatment (or new use of a treatment) with the current standard treatment.