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.

phases of a clinical trial

View a larger image of the phases of a clinical trial

Pre-clinical phase

pre-clinical phase



Preclinical phase is the early discovery and ongoing research conducted in the laboratory.

Phase 1

phase 1



Phase 1 clinical trials are studies aimed at determining the safety of an intervention and in the case of a medicine, the optimal dose.

Phase 2

phase 2


Phase 2 clinical trials are aimed at determining the effectiveness and safety of an intervention.

Phase 3

phase 3



Phase 3 clinical trials are aimed at determining whether a specific intervention is better, worse, or equally effective as the accepted standard of care.  In many cases this type of trial is needed to determine FDA approval.