Clinical Trials

What are clinical trials?

When doctors are uncertain about whether one type of chemotherapy is better than another, or if a new treatment or drug is likely to work or have side-effects, they try to answer this by involving patients in clinical trials. Most of the information that doctors have about how well different drugs work is obtained in this way. During a clinical trial detailed information is collected about each patient, drug side-effects and how well the treatment has worked. When this information is collected and compared from all the patients in a trial, it should become clear how good the treatment is. Without clinical trials it would be very difficult to know which cancer drug works best.

Common Questions

Are clinical trials safe?
All clinical trials have been passed by a committee of doctors and members of the public before they begin. Involvement in a clinical trial is completely voluntary. If patients decide that they want to stop being involved in a trial then they simply have to tell their doctor. This will not affect their chances of future treatment if other options are available.

Where do clinical trials take place?
Trials take place in a variety of locations including cancer centres and district hospitals. If patients are interested in discussing clinical trials then they should ask their cancer doctor for further information on what trials are available in their area.

Are there different types of clinical trial?
Yes, there are three different types of clinical trial which are detailed below.

Phase 1: A Phase I trial of a new drug, or mixture of drugs, is available if your cancer has returned despite having previous treatment or if there is no effective standard treatment available. If a new drug has been shown to work well in laboratory experiments and animal tests, it is important to know whether it also works well for humans, without causing too many side-effects. This usually involves weekly visits (sometimes more often) to the hospital to measure blood counts and assess side effects. Patients may like the close attention received during the visits but it can be disruptive to normal social and family activities. The dose of drug is increased with each new group of patients (usually three in each group). The higher the dose, the more likely side-effects are to occur, however, there may also be a greater chance of response.

Phase II: If results of a Phase I study show that a drug/treatment may be effective, without causing too many side effects, then the next step is to a Phase II trial. This will examine how well a particular drug works for a certain type of cancer. The dose that the patient is given remains the same throughout the trial.

Phase III: If a treatment has successfully passed through Phase I and Phase II, a Phase III trial is performed. This compares two different forms of treatment; usually the new treatment against the standard treatment. Phase III trials involve a larger number of patients than I and II, often involving hundreds of patients and taking many years to complete.

The links below contain more information on clinical trials in the UK, Europe & USA.

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