How do clinical trials work? 

Clinical trials are conducted in several phases, each one having a specific purpose: 

• Phase I: The new treatment is tested in a small group of volunteers - typically 25-30 people — to check for safety and dosage levels. Prior to this, the treatment may have been tested in a laboratory-based study. 

• Phase II: Once researchers are confident the treatment is safe at a certain dose they then test it in a higher number of people (perhaps 200-300) to further test how well it works, monitoring each stage for side effects and effectiveness. 

• Phase III: In this phase the study is rolled out to a much larger group of participants and compares the new treatment to those already in use. It helps confirm how well the new treatment works, and whether it performs better, or has fewer side effects, than what is currently available. 

• Phase IV: Phase four is the continuation stage, so after a treatment has been approved and made available to the public. The researchers track how the new treatment performs in the real world, and monitors the data to identify any long-term effects. 

Who can take part? 

Taking part in a clinical trial is completely voluntary. You will never be pressured into it, and will be given clear, detailed information about what’ is involved before deciding if it’s right for you. Trials follow strict ethical guidelines, and everything is reviewed and monitored by independent committees — usually linked to universities or hospitals — to ensure participants are protected at all stages and treated with care. 

How do I join a clinical trial? 

If you're interested in taking part in a clinical trial, the first step is to speak with your healthcare team or consultant — they can help identify studies that might be suitable for you. There are online databases that list current trials (see ‘More information’ below), or contact patient organisations such as Blood Cancer UK who offer guidance on what’s available and how to apply. Each trial will have its own eligibility criteria, and you'll be fully informed about what’s involved before you decide whether to take part. 

Why are clinical trials so important? 

Such studies help provide new treatment options for patients, especially in cases where current ones aren’t working well. For some, joining a trial may offer early access to a potentially effective new therapy that they may otherwise never get to try. 

They also are expensive to run. A single trial can cost hundreds of thousands — sometimes millions — of pounds and take years to complete. They need to be well-planned and highly-regulated, and researchers need to be fully confident about safety and efficacy at each stage before moving to the next.  Pharmaceutical companies tend to fund many of these studies, as they can benefit commercially from a successful outcome, but this means there is less funding for research into non-drug therapies, or treatments for rare conditions where the potential market is smaller. This is why researchers and patient groups often call for more government funding in those areas — especially for rare diseases and cancers.