Phase III Trials

Approximately one-third of drugs ever progress past Phase II research, and this small group of drugs then enters Phase III clinical trials. Phase III clinical trials are used to definitively conclude the efficacy of a drug for a certain condition. Phase III research are the largest and longest studies conducted, thereby making the process inherently more difficult that other phases.

Who Participates in Phase III Research?

Phase III clinical trials have the largest base of volunteers of all the phases, typically ranging from 300 to 3,000 participants who are afflicted with the targeted condition. Since Phase III research tests thousands of participants with similar demographic traits over the course of two to five years, this is the most time-consuming study in which to be involved.

Why is Phase III Research Conducted?

Phase III clinical trials further test the safety, efficacy and dosage of drugs in comparison with an existing treatment or placebo. Throughout the Phase III research, dosage levels are tested to determine which dose provides the most beneficial effects while offering the least negative side effects possible. This phase of clinical studies can also determine the effectiveness of the drug for different levels of the disease. Although few drugs make it to the Phase III trial, nearly 80% of those drugs in Phase III research progress to Phase IV.