Researchers spend many years developing new treatments or medicines in the laboratory before involving people. They then plan the clinical trial to progress in a series of up to four steps called phases. Information gathered in each phase determines whether the study can move on to the next phase, and whether the drug or treatment is approved for use. See below for a description of the different phases.
| To find out how to get involved in a clinical trial or another type of study, see Joining a study. |
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What are Phase 0 trials?
These are exploratory studies, sometimes referred to as “microdosing” or “pilot studies”. These trials are less common, and are used to test how the body responds to an experimental drug and whether it is worth moving on to a Phase 1 trial. A small dose of the drug is given once or for a short time to 10–15 people, sometimes to healthy volunteers. These trials do not offer any direct benefit to participants.
How the different phases work
Phase 1
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Phase 2
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Phase 3
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Phase 4
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Download a PDF booklet on this topic.
Additional resources
A/Prof Andrew Redfern, Consultant Medical Oncologist, Fiona Stanley Hospital, Clinical Academic Oncologist, The University of Western Australia, and Lead Clinician, State Breast Cancer Collaborative, WA; Christie Allan, Program Coordinator – Clinical Trials, Cancer Council Victoria; Bronwyn Chalmers, Clinical Trial Coordinator, Westmead Breast Cancer Institute, NSW; Sarah Coulson, Coordinator, Oncology Clinical Trials, Projects and Research, Tasmanian Health Service, TAS; Kate Cox, 13 11 20 Consultant, Cancer Council SA; Annette Cubitt, Clinical Trials Manager, Department of Medical Oncology, Cancer Care Services, Royal Brisbane and Women’s Hospital, QLD; Pete Currie, Consumer; Amy Ives, Clinical Trials Coordinator, Department of Medical Oncology, Cancer Care Services, Royal Brisbane and Women’s Hospital, QLD; Sabina Jelinek, Clinical Research Nurse, Murdoch Oncology Clinical Trials Unit, WA; Dr Visalini Nair-Shalliker, Research Fellow – Prostate, Cancer Council NSW; Karlie Neilson, Project Officer – Cancer Research Division, Cancer Council NSW; Prof Mark Rosenthal, Medical Oncologist, and Director, Parkville Cancer Clinical Trials Unit, VIC; Joan Torony, CEO, TROG Cancer Research, NSW; Rebecca Weselman, Senior Clinical Trials Coordinator, Oncology Clinical Trials, St John of God Murdoch Hospital, WA; John Williams, Research Governance Officer, Cancer Council NSW.
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