Phase III Clinical Trials → Study Design

Phase III trials are large-scale studies including between 300-3000 patients with the disease/condition of interest. For a rare disease/condition (such as an orphan drug that affects fewer people), fewer patients may be enrolled compared to a more common condition that may be able to enroll thousands of patients.

The trials are longer in duration, typically from 1-4 years in length, and are designed to detect long-term side effects not seen in earlier clinical trials. The larger number of participants also allows researchers to identify rare side effects that went undetected in the smaller sample sizes of previous phases.

This phase is typically double-blinded, randomised, and controlled to eliminate research bias and improve the power of the study’s results.

Clinical Trial Phases may overlap, as well.