The purpose of clinical trials for brain tumour patients is to advance understanding of these tumours and to improve diagnosis and treatment. By their definition, clinical trials are experimental, and while the hope is that they will be beneficial, there is no guarantee.
What is a clinical trial?
A clinical trial is an experiment that involves patients in a new way of managing a condition. Trials are vital to establish whether a new approach is better than the old one.
Developing a new treatment
There are normally four phases to developing a new treatment:
After a treatment is tested in the laboratory, it goes into Phase 1 trials. These set out to answer:
- whether the treatment is safe
- whether it has any side-effects
- what is the right dose to use
Initially, the treatment is given at a low dose to a small group of people, who may be health volunteers. If the group experiences no serious side-effects, another group is given the drug at a higher dose. This process is repeated until the 'maximum tolerated dose' or MTD is determined.
In phase 2, the aim is to find out more about the safety and about whether the new treatment does what is hoped (referred to as its 'efficacy'):
- Is it any good?
- Does it shrink the tumour?
- Does it keep the tumour away for longer? ('progression-free survival')
- Does it make the patient feel better?
- Is the treatment safe and well-tolerated?
This phase uses a larger group of patients (up to about 100) and can last for a couple of years.
Phase 3 looks at whether the new treatment works better than the existing, 'standard' treatment or whether it produces fewer side-effects. This is done by comparing two groups of patients with similar characteristics. Some of the patients receive the standard treatment and some receive the new treatment. The outcome of the two groups is compared to see whether the new treatment is better.
Which treatment patients receive (standard or new) is often decided on a random basis. It is the most successful way of ensuring that the results of the trial are not biased and is known as 'blinding'.
These trials are on larger groups of people (several thousand patients), who are usually ill, and often last a year or more.
Phase 4 trials are conducted when a drug has been shown to be effective and has been licensed to treat an illness. This phase aims to find out what happens when the drug is given to thousands of people in the general community. The aim is to assess any long-term risks and benefits of the drug, and any rare side effects.