Why do we need clinical trials?
None of the existing treatments result in a cure of all patients, nor are they without side effects, and doctors continue looking for better ways to treat the disease.

What information do we get from clinical trials?
Any new treatment or procedure will be investigated using a whole series of clinical trials, each one designed to answer a specific set of questions.

Clinical trials are also organised into different phases of research, in order to build up a greater understanding of the new treatment, before it is approved or recommended for routine use.

Clinical trial: Phase I - the first studies in humans are Phase I trials. They are performed with small numbers of patients or healthy volunteers and are used to answer questions such as what dose of the drug is likely to be effective and what side effects might occur.

Clinical trial: Phase II - these trials continue this process with larger numbers of patients.They have a greater focus on how well the treatment or procedure works, perhaps in particular situations or groups of patients.

Clinical trial: Phase III - these trials enrol large numbers of patients and are used to compare the effectiveness and safety of the new treatment with that of the standard existing treatment. Information obtained from large Phase III trials that demonstrates the benefits a new drug over the existing treatments is sometimes presented to regulatory authorities in order to obtain a licence to market and sell the drug.