What are clinical trials?

Clinical trials are medical research studies aimed at improving health and cancer care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose, or treat cancer. Participation in research is voluntary and it is important that if you take part in a trial you do not feel coerced.

Clinical trials are an essential process for the development of new medicines or treatment and to evaluate how people respond to them. The studies are performed for and with cancer patients to find out whether promising approaches to cancer prevention, diagnosis, and treatment are safe, effective and better than currently available treatments.

With new drugs that are now available, extensive clinical trials are required by government health authorities before the drug is available to the public. Usually if the trial drug does not show any benefits over the current treatment then the drug does not get registered and is not available for use.

New Zealand has a proud track history of successfully performing and being involved in many clinical trials.

What are the different types of clinical trials?

There are various types of trials, those listed below are the most common:

Treatment trials
Test new treatments eg. a new cancer drug, new approaches to surgery or radiation therapy, new combinations of treatments, dose effectiveness or new methods of treatment such as gene therapy.

Prevention trials
Test new approaches that best prevent new and recurring forms of cancer. Trials may include the testing of medicines, vaccines, vitamins, minerals, or other supplements with patients. The aim for these trials is to find ways to lower the risk of a certain type of cancer or disease.

Screening trials
Test the best way to find disease or conditions such as cancer, especially in its early stages.

What are the different phases of clinical trials?

Most clinical research that involves the testing of a new drug progress in a series of steps, called phases. This allows researchers to analyse data in a way that results in reliable information about the drug and protects patients.

Most clinical trials are classified into one of four phases:



Phase One

These are the first studies in humans after extensive studies in animals. In cancer trials the patients involved usually have cancer. The number of patients in Phase I trials are usually small. Information and data are gathered and analysed to see how the drug affects patients and about its effect on the cancer.


Phase Two

Trials continue to test the safety of the drug, and begin to evaluate how well the new drug works. Phase II studies usually focus on a particular type of cancer. 


Phase Three

These studies test a new drug, a new combination of drugs, or a new surgical procedure in comparison to the current  'standard of care', meaning the trial compares the new drug to the therapy that is usually given to a patient who is not in the clinical trial.

A participant will usually be assigned to the standard group or the new group at random. Each group or "arm", as they are often referred to, may not know to which group they have been allocated. This ensures results are not biased.

Phase III trials often enrol large numbers of people and may be conducted across many doctors' offices, clinics, hospitals and cancer centres worldwide.

In addition, after a treatment has been approved by a government regulatory body such as MEDSAFE it is marketed to the public.


Phase IV

The drug's maker may then study the available drug further in a Phase IV trial. The purpose of Phase IV trials is to evaluate the side effects, risks, and benefits of a drug over a longer period of time and in a larger number of people than in Phase III clinical trials.

What are potential benefits and risks of being involved?

For participants with melanoma entering into a clinical trial the rules are different and there is no compensation paid. There may be some benefits which may be gained, as well as risks associated with being a participant in a clinical trial too, such as: 



  • access to the newest and most up to date drugs and medical experts
  • regular hospital or clinic visits and tests to review the response to the drugs taken
  • access to cutting edge treatment regimes




  • unpleasant, serious or even life-threatening side effects

  • treatments may not provoke the response anticipated and be ineffective
  • more time and involvement is required than is usual for standard treatments and frequent hospital visits may be difficult for patients who need to travel to the appointments or are feeling unwell

What other important factors are there to think about?

  • Clinical trials can be randomised, which may mean that rather than receive the trial medication(s) you may receive placebo(s)
  • If the trial is a double blind randomised trial, neither you or the medical team involved in your care will know which type of medication you are receiving

On all accounts, all clinical trials are ethically approved and monitored. Eligible patients often gain a better understanding of their cancer and their treatment when taking part in a clinical trial. There is also evidence to suggest that patients have a better clinical outcome when they are involved in clinical trials than those receiving standard care.

To learn more or to discuss a clinical trial please speak to your Oncologist or go to the Clinical Trials NZ website.