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- Patients selected for these trials are almost always in cancer research centers and have already received all
- known effective anticancer therapy. After the proposed treatment is explained to them, they may volunteer
- to receive the new treatment. There is, therefore, no moral objection to giving this new treatment. Since there
- is "nothing to lose," it is hoped that a specific new agent may in fact prove effective.
- This phase is completed when no unusual problems or toxic effects have been found and the dose
- necessary to produce a biologic effect has been determined. The study can then move to the next phase.
- • Phase II Ten to 20 patients are treated, each with various types of tumors known to be responsive to
- chemotherapy . These might include lymphomas, breast cancer or colon cancer. Since these tumor types are
- known to be responsive, the patients will be those who have already received all standard forms of therapy
- that seem reasonable. The use of a Phase II trial does not deprive anyone of any therapy known to be
- effective. If a significant number of patients with each type of tumor respond to the therapy, the trial moves
- to the next level.
- • Phase III In this phase the new therapy is compared with standard treatment to see if there is an
- improvement in the response or if the same response rate is achieved but with less-toxic side effects.
- A therapy tested in a clinical trial does not necessarily involve a drug not already in clinical use. A new
- treatment often consists of standard drugs used in a new combination or a new sequence, in new dosages or
- even simply given in a new way. But if a new drug is involved and the Phase III trial is successful, the
- National Cancer Institute will approve the drug for general use. Eventually, the new therapy might become
- the standard therapy.
