New therapies require rigorous evaluation before they become part of routine clinical care.
The process of evaluating new drugs and devices is well established. When a new approach to treatment is ready for human trials, a phase 1 study is conducted with small numbers of patients so that common treatment-related toxic effects can be identified rapidly. Armed with an understanding of the types of problems that may accompany the new therapeutic approach, investigators conduct a phase 2 study, usually involving many more patients, to assess the potential therapeutic efficacy. Only after the technical feasibility is established, common toxic effects are identified, and some promise of effectiveness is documented are randomized clinical trials, often termed phase 3 trials, conducted to compare the new approach with the current standard of care. These trials constitute the gold standard used in evidence-based decision making.