How do clinical trials work?

In general, this is how clinical trials work –

The data (or measurements) from all patients receiving the trial treatment is collected together.

Then, it is compared to data from one of two sources:

• control patients – these are patients on the same trial who received a dummy or placebo medicine, such as a ‘sugar pill’,  instead of the trial treatment
• the natural history of the disease – these are the measurements from many patients which have been collected over many years

Then, clinical trial doctors can see the difference between the measurements from patients who have received the trial treatment and the measurements from patients who have not received the trial treatment.

This enables the doctors to judge if the trial treatment is safe and works better than existing treatments or no treatment.

If the results show that the trial treatment is safer or better, the doctors will apply to the Government to make the treatment available to patients. They will use the clinical trial data as evidence when they make their application.