Understanding cancer clinical trials

What are clinical trials?

Clinical trials are medical research studies, involving patients, to test new treatments. The aim is to test how different treatments work by looking at

• Preventing cancer
• Screening
• Treatments
• Diagnosing
• Controlling Symptoms

 Some trials test new medicines whilst others look at new combinations of existing medicines. Different trials have different aims. Some may be to test whether a treatment given in a different way is more effective, whilst another may look at reducing side effects. Others may look at prevention of a disease in the first place. There are also trials for surgery, radiotherapy and the use of medical devices such as artificial joints.

Why are clinical trials important?

Clinical trials are needed to extend knowledge and improve treatment and care, now and for the future. Without on-going clinical trials it would not be possible to add to current knowledge about effective treatments. They are the best way to compare different approaches to prevention and treatment.

Trial design

Clinical trials are carried out in different stages, called Phases – of which there are 4:

• Phase 1 - involves small numbers of participants/patients (generally 20-80). It is designed to determine how the drug is broken down by the body and how it interacts with the body. It may also reveal some side effects of the drug.
• Phase 2 – involves relatively small numbers (few hundred) of participants who have disease or condition of interest. The aim is to build on information gathered in phase 1, and assess responses to treatment.
• Phase 3 – involves large numbers (several hundred-thousands) of patients. Often comparing a new treatment with the best treatment available. The following are monitored:
  • Effect of treatment on cancer
  • How long the effect lasts
  • Side effects
  • Any possible longer term problems

The studies are usually randomised, and sometimes double blinded. They often include Quality of Life studies. At the conclusion of a properly designed phase 3 trial, the new treatment will be found to be inferior, equivalent, or superior to the standard treatment.

• Phase 4 - aims for additional information on doses, schedules, stages of disease, finance and quality of life

Terms associated with clinical trials

Joining a trial

A doctor, nurse or other researcher must have a patients’ permission to enter them into a clinical trial. The patient must give their consent to participate in the trial. There are a few instances where this agreement may be gained from a relative or other legal representative.

Informed Consent

To help the patient make the decision of participating in a trial, the following should be clearly explained:

• What the study is trying to find out
• What the treatment is and what the patient will need to do
• Any possible risks
• What the benefits are

The patient should also be given a Patient Information Sheet (PIS) that explains the trial, which they can take home and read. They can also discuss it with family members. If the patient decides to enter the trial, they will be asked to sign a form that says they agree to join and have done so of their own free will. If the patient decides not to enter the trial, their decision will be respected and they will continue to receive the usual appropriate medical treatment. he patient can choose to stop participating in the trial at any point, and they will also continue to receive the usual appropriate medical treatment. An interpreter can be made available for those who do not speak English.

Treatment & Follow up

Once consented to a trial, the patient will receive treatment as per the trial protocol and then attend follow up appointments with the doctor and research nurse. Information will be gathered from these appointments, sometimes by way of a questionnaire, to assess the effectiveness of the treatment or other aspects that the trial is looking at.

This information will be gathered alongside all other participants’ by the researcher running the trial. The trial may run for years so it may be some time before the results of the trial are known.

All information is confidential and the patients name will not be disclosed in any reports about the trial.

If you would like to take part in a clinical trial you should discuss this with your doctor or nurse. They may know of a trial that is suitable for you, but it should be remembered that there may not be a trial which is suitable for you.

Organisations

You can find more information at the following sites:

MRC Clinical Trials Unit

The James Lind Library

The NIHR Clinical Research Network Coordinating Centre (NIHR CRN CC)