Phase II Clinical Trials Does It Work?
If a new treatment is found to be reasonably safe in phase I clinical trials, the treatment can then be tested for effectiveness in a phase II clinical trial. Usually, a group of anywhere from 25 to 100 patients with the same type of cancer receive the new treatment in a phase II study. They are treated using the dose and method that were determined most likely to be safe and effective in phase I studies. In a typical phase II clinical trial, participants all receive the same dose, and no placebo is involved. Some phase II studies do, however, involve randomizing participants into 1 of 2 treatment groups, similar to what is done in phase III trials (see below). These groups may get different doses or get the treatment in different ways to see which provides the best balance of safety and effectiveness. Phase II studies are often conducted at major cancer centers but may also be done in community hospitals or even doctors’ offices. Doctors look for some evidence that the treatment is ef
