Most clinical research progresses in an orderly series of steps or phases.
Phase II trials provide preliminary information about how well the new drug works, and generates more information about its safety and benefits. A Phase II study usually focuses on a particular type of cancer. Phase III trials compare a promising new drug, combination of drugs, or procedure with a current standard of treatment. Clinical trial protocols are the action plans or guidelines that must be followed during the course of any study. Large cancer centers, university hospitals, local medical centers, or physician offices, all may be included in managing clinical trials.