Clinical Trials - Phase II
In this phase the effectiveness and safety of the experimental study drug or treatment is evaluated by controlled studies. The study drug or experimental treatment is tested on a larger group of people ( 100- 300) compared to a phase I study. This second phase of testing may last from several months to two years.
Since this phase of the study is designed to see if the drug works, patients are given the highest dose that does not cause severe side effects (determined from the phase I study) and are closely observed.
Phase -II studies also help determine, risks associated with the drug as well as short term side effects. Based on the efficacy or toxic effects of the drug / treatment in a Phase -II trial the outcome of the development process could be decided, i.e if a Phase -III trial would be required.