What are clinical trials?

Clinical trials are research studies that are carried out on humans. Clinical trials test if new treatments are safe and effective. These trials help regulators (organisations that oversee clinical trials) decide if to approve new treatments.

New treatments can include new:

• medicines
• vaccines
• medical devices
• diagnostic tests
• Clinical trials may also test new lifestyle advice or a change to a health service.

Clinical trials can involve both healthy people and people with a medical condition.

Clinical trial and research ethics

Before a clinical trial can go ahead, a human research ethics committee must agree that it is ethical (fair and respectful).

The ethics committee often has a range of members that include:

• at least two members of the public (at least one man and one woman)
• a person involved with pastoral care (emotional and spiritual support) in the community
• a lawyer
• researchers
• people with professional caring experience, such as a nurse or allied health professional

Why are clinical trials needed?

Clinical trials allow researchers to find out whether a new test or treatment is both safe and effective in humans.

Before a clinical trial begins, researchers will have already done tests in a laboratory, sometimes using animals. Clinical trials check that the positive results seen in these tests also happen in humans. They can also identify any safety concerns and possible side effects for new treatments.

Clinical trials help researchers find out which people will benefit most from a new test or treatment.

Clinical trials lead to new tests, treatments and devices that help people better manage their health conditions. Most new medical treatments and tests are a result of clinical trials.

Phases of clinical trials

Clinical trials of new medicines usually take place in phases (stages). These start with small numbers of people to check that the medicine is both safe and effective. The phases of a clinical trial are:

• Phase I clinical trials are usually the first trials to happen in humans. This usually involves giving the treatment to a group of fewer than 100 healthy volunteers to check that it is safe.
• Phase II clinical trials are often the first trials in people with the disease or condition of interest. The new medicine might be given to a few hundred people to check that it is safe and works. This phase can also help set the right dose.
• Phase III clinical trials involve giving a larger group of people the new medicine. Often the new medicine is compared to other standard tests or treatments for the specific disease. Phase III trials only happen if good results are seen in Phase II.
• Phase IV clinical trials happen after the new test or treatment is available to use. These studies check how well the test or treatment works in the general population. Phase IV studies also collect information about side effects over a longer time.

What are the different types of clinical trials?

The 3 main types of clinical trials are:

• Treatment trials — test new medicines, combinations of medicines, new medical devices or new approaches to surgery.
• Diagnostic or screening trials — check tests used to detect diseases.
• Prevention trials — test new ways to prevent diseases. They might include medicines, devices, vaccines, vitamins, lifestyle or behaviour changes.

Do all participants in clinical trials get the new medicine?

In Phase III and IV clinical trials, people are often divided into groups. Depending on your group and the design of the clinical trial, you may receive:

• the new test or treatment
• the standard treatment

If there is no standard treatment, you may receive a placebo. A placebo is something that looks identical to the treatment but has no clinical effect. Placebos may be called inactive or dummy treatments. Using a placebo comparison helps researchers check if a treatment works without the impact of psychological effects.

Clinical trials randomly assign participants to the different groups. This means that you do not get to decide which group you go in. You also may not be told which treatment you are receiving until after the trial has finished.

Why should I take part in a clinical trial?

You may be asked to take part in a clinical trial by your healthcare professional. If so, the benefits may include:

• earlier access to a new test or treatment
• closer monitoring than standard care
• playing an active part in your treatment
• knowing that you are helping others by taking part

Are there any risks in taking part in a clinical trial?

There can also be risks or disadvantages when taking part in a clinical trial. These may include:

• possible unpleasant side effects of the test or treatment
• inconvenience — you may need more treatment, tests or hospital visits than usual
• the test or treatment might not work for you

You should talk with your doctors and the researchers before deciding to take part in a clinical trial.

You can find a list of questions that you may want to ask here.

Who can take part in a clinical trial?

Every clinical trial has a protocol. The protocol describes which people can take part in the clinical trial. This is called the inclusion criteria and often includes:

• age
• sex
• type or stage of disease
• previous treatments

There will also be a list of characteristics that are not wanted in each clinical trial. These are called the exclusion criteria.

What is informed consent?

In Australia, people must understand all the facts about a clinical trial before they can agree to take part. This is known as informed consent.

The researchers need to make sure that you understand:

• the study's purpose
• how long the study will last
• what tests and procedures you will have
• who you can contact if you have any concerns during the study
• any potential risks or benefits to you, your family and carers

Researchers usually give you this information in a document called the Patient Information Statement.

What happens if I change my mind and no longer want to take part?

If you decide that you no longer want to take part in a clinical trial, you should talk with the research team. You will still be able to receive standard (usual) care if you choose to leave the clinical trial.

After you leave the trial, your doctor will talk with you about other treatments for your disease.

The researchers can tell you what will happen to the data that they have already collected.

Resources and support

You can find out more about relevant clinical trials by:

• talking to your doctors
• contacting the relevant support groups or consumer health organisations in Australia
• looking at information on australianclinicaltrials.gov.au

The Australian Clinical Trials website has information on:

• the importance of clinical trials
• finding a clinical trial right for you
• clinical trial eligibility

If you are specifically looking for information about cancer trials, visit Cancer Australia's Australian cancer trials website.

Languages other than English

• The VCCC Alliance has a fact sheet to help understand 'Is a clinical trial right for you?' available in many different languages.
• Health Translations has a video about clinical trials available in many community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

• Find out more about clinical trials on the Our Mob and Cancer website.