Phase II Trials

Phase II clinical trials evaluate the efficacy of new drugs, the safety of said treatments and dosage specifications. Unlike Phase I trials, which may require healthy volunteers, Phase II research is targeted to patients afflicted with the condition the drugs intend to treat. On average, Phase II clinical trials can take anywhere from one to several years to be completed.

Phase II Research: Suitable Participants

Phase II clinical trials usually require randomized populations of approximately 300 patients to conduct the study. Patients must be afflicted with the condition for which the drugs are intended to accurately evaluate the drugs’ dosage, efficacy and safety. Therefore, Phase II trials are more discerning and strict in the type of patient who can participate.

Phase II Research: The Purpose

During Phase II clinical trials, it is possible to determine whether patients’ conditions improve, identify side effects and evaluate the most effective dosage in terms of how it relates to the human body. Phase II trials are often double-blinded, meaning that neither the researcher nor the patient knows which is the control group receiving a placebo and which is the group receiving the treatment. Volunteers are randomly assigned to these groups. Since Phase II trials are so targeted and comprehensive, very few new drugs make it past this phase of research.