Clinical trials are an opportunity to conduct biomedical or health-related research studies on human beings. Prior to a trial commencing, there must be proven efficacy in a non-clinical environment (usually a laboratory) and the trial must be approved by health authorities and an ethics committee. In Australia, the Therapeutic Goods Administration (TGA) is involved in approving clinical trials.

Clinical trials require funding in the form of sponsors. A variety of individuals and organisations can sponsor a clinical trial. These include: pharmaceutical companies, medical organisations, voluntary/charitable groups and some government agencies. Clinical trials can be held in a variety of places, depending on the requirements of the study. Most trials are conducted in hospitals, doctors' offices, universities, or community clinics.

Clinical trials proceed over a variety of phases. First testing on humans is classified as a phase I clinical trial, and this involves only a small group of participants (20-100). The primary purpose of a Phase I trial is to determine the clinical safety of the therapeutic. A therapeutic must show safety in the Phase I stage before trials can proceed to Phase II. Phase II studies continue to observe safety, whilst also determining dosage requirements and the efficacy of the drug. Phase II trials involve a larger group of participants (50-300). Should a therapeutic be considered both safe and effective after Phase II testing, the study may move on to Phase III.

Phase III trials involve a much larger group of participants than the other stages of testing (300-5000+). Often, a therapeutic which has been approved for sale by the relevant authority (TGA in Australia) will have successfully undergone two Phase III trials before being marketed.  

Links

• Australian New Zealand Clinical Trials Registry – The Australian New Zealand Clinical Trials Registry (ANZCTR) is an online register of clinical trials being undertaken in Australia, New Zealand and elsewhere.
• Clinicaltrials.gov - A service of the US National Institutes of Health. Provides information relevant for both Australian and US trials.
• Therapeutics Goods Administration - The TGA are responsible for registering and approving Australian clinical trials. The TGA website includes a substantial amount of information for anyone wishing to register a clinical trial in Australia.