The phases of a clinical trial

Glossary

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.

Learn more about:

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

Participants
10–100
Purpose
  • first study in people
  • tests safety of new treatment
  • finds the safest dose and the best way a treatment can be given
  • identifies side effects
  • studies how the intervention works with other medicines or food (interactions)
How it works
  • participants are given a fixed dose and watched closely for side effects
  • if no side effects, dose is increased in next group of participants, this continues until noticeable side effects appear
 More info
  • patients sometimes benefit from having the new treatment but great improvements in their condition are uncommon

Phase 2

Participants
100–300
Purpose
  • builds on the results of Phase 1
  • continues to test safety of a drug
  • begins to assess how well a new treatment works on the disease
How it works
  • often focuses on one cancer type
  • all participants receive the same experimental treatment
  • sometimes randomised controlled trial – i.e. participants are put into separate groups and given different treatments, which are then compared to see how well they treat the disease
 More info
  • people often have treatment as an outpatient, but occasionally need to stay overnight in hospital for monitoring

Phase 3

Participants
100s–1000s
Purpose
  • tests if the new treatment is better than the standard treatment
  • compares side effects, survival and quality of life
  • assesses whether the risks outweigh the benefits
  • collects information that allows new treatments and existing treatments to be used in new ways or for different diseases
How it works
  • uses two or more treatment groups – experimental and control
  • usually groups are randomised and sometimes blinded
  • placebo may be used for comparison
  • runs over a long period of time
 More info
  • Phase 3 trials help the Therapeutic Goods Administration (TGA) assess whether a new drug should be registered for use in Australia

Phase 4

Participants
1000s
Purpose
  • identifies how well treatment works when used more widely
  • monitors the long-term benefits and risks
  • looks for other uses of the drug or treatment
How it works
  • carried out after a treatment has been registered by the TGA
  • usually run by pharmaceutical companies that make the product
  • may be used as a way to provide early access to a drug after TGA approval but before Pharmaceutical Benefit Scheme (PBS) approval
  • sometimes called expanded access study
 More info
  • not all treatments go through Phase 4 studies
  • they are less common than Phase 1–3 trials

Listen to our podcasts on Coping with a Cancer Diagnosis and Making Treatment Decisions

Click on the icon below to download a PDF booklet on clinical trials and research.

    Understanding Clinical Trials and Research

  • 298 kB

Printed copies are available for free - Call 13 11 20 to order

Instructions for downloading and reading EPUB files

Apple devices

The iBooks application must be installed on your Apple device before you can read the EPUB.
Different ways to download an EPUB file to your Apple device:

  • email EPUB files to yourself and transfer the attachment to iBooks.
  • copy EPUB files into DropBox (or a similar service) and use the DropBox app to send them to iBooks.
  • open EPUB files directly from Mobile Safari and open them in iBooks, where they are saved automatically by downloading the EPUB from the website.

Need more help? Visit: http://support.apple.com/kb/HT4059

Kobo

To download an EPUB file to your Kobo from a Windows computer:

  • download and save the EPUB directly onto your desktop.
  • connect your Kobo to your computer using the USB cable and tap “Connect” on your eReader.
  • select “Open folder to view files” to view the contents of your Kobo.
  • navigate to where you have stored your EPUB file in “Finder”, in documents or downloads, and drag and drop it into the Kobo window. You can now disconnect your Kobo to read the eBook.

To download an EPUB to your Kobo from a Mac:

  • download and save the EPUB directly onto your desktop.
  • connect your Kobo to your computer using the USB cable and tap “Connect” on your eReader.
  • open your “Finder” application.
  • select “Kobo eReader” from the listed devices to view the contents of your Kobo.
  • navigate to where you have stored your EPUB file in “Finder”, probably in documents or downloads, and drag and drop it into the Kobo window. You can now disconnect your Kobo to read the eBook.

Turn on your Kobo and your EPUB will be located in “eBooks”, while a PDF will be located in “Documents”.
Need more information? Visit: http://www.kobo.com/help/koboaura/response/?id=3784&type=3

Sony Reader

To download an EPUB file on your Sony Reader™:

  • ensure you have already installed the Reader™ Library for PC/Mac software
  • select the eBook you want from our website and click the link to download it.
  • connect the Reader™ to your computer.
  • open the Reader™ Library software and click “Library” in the left-hand pane and select the eBook to view it.

Need more help? Visit: https://au.readerstore.sony.com/apps_and_devices/

Amazon Kindle 2nd Generation devices

EPUB files can’t be read on the Amazon Kindle™. However, like most eReaders, Kindle™ 2nd Generation devices are able to display PDFs. We recommend that you download the PDF version of this booklet if you would like to read it on a Kindle™.
To transfer a PDF to your Kindle™ via USB cable from your computer or Mac:

  • download the PDF directly onto your computer.
  • connect the USB cable to your computer’s USB port, and the micro USB end of the cable to your Kindle™. Note: the Kindle™ won’t be available as a reading device while it is connected to your computer until it has been disconnected.
  • open the Kindle™ drive and several folders will appear inside. The “Documents” folder is where you will need to copy or drag the PDF to.
  • safely eject your Kindle™ from your computer and unplug the USB cable. Your content will appear on the Home Screen.

Kindle also provides a Kindle Personal Documents Service that allows users to send documents as an attachment directly to your eReader. For more information on this service, visit http://www.amazon.com/gp/help/customer/display.html/ref=help_search_1-1?ie=UTF8&nodeId=200767340&qid=1395967989&sr=1-1
For more information on accessing a PDF on your Kindle™, visit www.amazon.com/manageyourkindle, log in to your account and click on Personal Document Settings.
Need more help? Visit https://www.amazon.com/gp/help/customer/display.html?nodeId=200375630

Android and PC

You can also download and open eBooks on Android devices and PCs with appropriate apps or software installed. Suitable eReader apps for Android include Google Play Books, FBReader and Moon+ Reader. Suitable software for PCs include Calibre and Adobe Digital Editions.

This information was last reviewed in July 2018
View who reviewed this content
View our editorial policy

Support services

Coping with cancer?
Speak to a health professional or to someone who has been there, or find a support group or forum

Need legal and financial assistance?
Pro bono services, financial and legal assistance, and no interest loans

Looking for transport, accommodation or home help?
Practical advice and support during and after treatment

Cancer information

Cancer treatments
Learn about common cancer treatments, such as surgery, chemotherapy and radiation therapy

Dealing with the diagnosis
Common reactions to a cancer diagnosis and how to find hope

View our publications
Guides and fact sheets for people with cancer, their families and friends

TOP BACK TO TOP