Phase II Trials

Phase II clinical trials test the efficacy of drugs, continue to assess the safety of the treatments and further assess dosing requirements. Phase II research is targeted to those patients who suffer from the condition which the drugs are intended to treat. Typically, Phase II clinical trials can take one to several years from inception to completion.

Who Participates in Phase II Research?

Randomized groups of up to 300 patients are typically used as volunteers in the Phase II clinical trials. Patients for Phase II research must have the condition for which the drugs or treatment is intended. For this reason, Phase II trials are more selective and stringent in who is selected to participate.

Why is Phase II Research Conducted?

Phase II clinical trials are used to examine whether patients improve, identify common side effects, learn if the dosage should be reduced or increased and determine how the body responds to the varying drug dosages. During this stage, volunteers are assigned to separate groups where only one group will actually take the drug. The other group will receive a placebo as a method of control. Phase II clinical studies are typically double-blinded, where neither the researcher nor the patient knows which group is taking the drug and which group is receiving the placebo. Very few new drugs make it past Phase II research.