Clinical Trials

Clinical Trials

A clinical trial is a research study. Clinical trials have played a huge role in the dramatic improvements in childhood cancer cure rates in the last 30 to 40 years.


Key points to remember

  • research into new methods of treating and diagnosing cancer is happening all the time
  • researchers may look at new medicines, a new combination of medicines or a new surgical procedure, or ways of finding out more about cancer
  • they do this by using a clinical trial
  • clinical trials have played a huge role in the dramatic improvements in childhood cancer cure rates in the last 30 to 40 years
  • clinical trials also look at reducing side effects of cancer treatment (supportive care)

What is a clinical trial?

This page is part of a whole section about childhood cancer.

A clinical trial is a research study. Researchers use clinical trials to:

  • answer questions about established treatments, new treatments or new ways of using existing treatments
  • investigate different ways to diagnose cancer and other diseases
  • investigate how to monitor the disease during and after treatment

Some trials look at ways of reducing the side effects of treatment. Often, clinical trials have questions about treatment, diagnosis and supportive care all within the one trial.

Researchers run most clinical trials at a number of institutions around the world at the same time. That means trial questions can be answered accurately and in a reasonable timeframe. Clinical trials have played a huge role in the dramatic improvements in childhood cancer cure rates in the last 30 to 40 years.

What are the different types of trials?

There are 3 phases of a clinical trial.

Phase 1 trials

These study brand new medicines.

Phase 2 trials

These study medicines which have graduated from phase 1 trials. Researchers test the medicines with a greater number of people and sometimes with different doses.

Phase 3 trials

These are the ones that most children are enrolled in. Researchers compare what has been used as the 'standard treatment' with a new form of treatment. In this way, the trial is a refinement rather than experimentation.

How are phase 3 trials applied?

To make comparisons between treatments, patients in a trial receive one treatment or the other. This means that one group of children will receive 'treatment A' and another group will receive 'treatment B'. Sometimes there are more than 2 groups. A computer makes the selection. The computer has no information about your child - the decision is random.

What about the results?

The results of the research and treatment will not be available until all the patients have completed the treatment course. This may take several years. But researchers regularly review the records during the trial. If they discover important information, they tell each doctor involved. The doctors will share this with participants. That way, they share all the findings.

Does my child have to join a clinical trial?

You do not have to consent to your child joining a clinical trial. If you do, you can withdraw your child from the trial at any time. If this happens, your child will receive the standard treatment.

How do I make a decision about my child joining a clinical trial?

Your child's doctor will explain everything to you and provide all the information you need to help you to make an informed decision.

Also, there is an information sheet for each clinical trial. It details the course of treatment (called the protocol), possible side-effects and any necessary tests. It will also tell you what information and specimens will be collected and sent to the overseas centre.

Questions to ask your doctor

Here are some of the questions you may wish to ask your doctor. You may also want some of the medical terms explained.

  1. What type of trial is this and why is it being done?
  2. What exactly will the researchers do during this trial?
  3. How long will the trial last?
  4. How will it affect us – are there any extra tests or hospital visits?
  5. What are the benefits and risks and other available treatments?

What safeguards are in place?

There are safeguards in place to protect patients participating in clinical trials. The 3 main ones are:

  1. Informed consent.
  2. Deciding if a clinical trial is safe.
  3. NZ specific safeguards.

What is informed consent?

Informed consent is a process. Your doctor and other health professionals will share information and advice with you and your child. The information and advice will help you both to decide whether or not to consent to being part of a clinical trial.

The ethical basis for the principle of informed consent comes from Right 7 of the Code of Health and Disability Services Consumers' Rights. You can ask for a copy of the Code at your hospital.

What about NZ specific safeguards?

Every clinical trial requires careful assessment by an ethics committee. It is the responsibility of the committee to make sure that it is ethically acceptable for children to participate in the trial. Even though most clinical trials are developed overseas, a New Zealand ethics committee must review each trial before it gets approval in this country.

The following organisations sometimes review and approve clinical trials in New Zealand:

  • Medsafe (New Zealand Medicines and Medical Devices Safety Authority)
  • district health board review committees

A Māori consultant or a Health Research Committee which is iwi representative also reviews clinical trials for cultural acceptance.


All the pages in the childhood cancer section of this website have been written by health professionals who work in the field of paediatric oncology. They have been reviewed by the members of the National Child Cancer Network (NZ). Medical information is authorised by the clinical leader of the National Child Cancer Network.

This page last reviewed 24 August 2018.

On this page