Phase III Trials

Very few new drugs ever make it past Phase II research. In fact, only 1/3 of drugs ever make it to Phase III clinical trials. The drugs that progress to Phase III are definitively tested for effectiveness in the treatment or cure of a specific condition. Phase III research is intrinsically more complicated than other phases, as these trials are the longest and largest out of all the studies conducted.

Phase III Research: Suitable Participants

Anywhere from 300 to 3,000 participants are required to conduct Phase III clinical trials. Phase III trials have the largest base of patients, all living with the targeted condition that the drug id intended to treat. As the most time-consuming and demanding trial in which to be involved, Phase III research uses patients with similar demographic traits and tests them for a duration of two to five years.

Phase III Research: The Purpose

Phase III clinical trials act as more intensive extensions of the first phases of research, testing the ultimate safety, efficacy and dosage of drugs as compared to the current gold standard treatment or placebo. Dosage levels will be modified to determine the dosage that provides the most beneficial effects while offering the least negative side effects. During Phase III research, the efficacy of the drug on various levels of the disease is also tested. Though making it to Phase III trials is unlikely for drugs, almost 80% of those that do enter Phase III trials move on to Phase IV.