trial managers

Clinical trials

What are clinical trials?

What happens in a clinical trial?

What are the different phases of a clinical trial?

Why is it challenging to get people involved?

Why is getting people to participate in clinical trials so important?

What are clinical trials?

Clinical trials are research studies with humans, designed to test new treatments to find better ways to prevent, detect or treat disease1. Clinical trials are also sometimes referred to as interventional trials. The sorts of treatments being investigated include medicines or drugs, cells and other biological products, surgical procedures, radiologic procedures, devices, behavioural treatments, process-of-care changes, preventive care, and other items.2 Clinical trials rely on having members of the general public agree to take part.

What happens in a clinical trial?

In a clinical trial, participants meet with researchers who go through what the clinical trial will involve. All participants must be advised about the objectives of the research, what is expected of them, as well as any risks that may be experienced during and after the trial.

Trials must follow a carefully controlled protocol, which is a plan that describes what researchers will do in the study. This plan needs to be reviewed and approved by an independent ethics panel before the trial starts.

What are the different phases of a clinical trial?

There are typically 4 phases3 of clinical trials.

Phase 1 involves just a few volunteers, as this is the first time a new treatment is tested in humans. The purpose is to test what happens in the body. Approximately 70% of treatments move to Phase 24.

Phase 2 involves a larger group of volunteers, often up to a few hundred people, who usually have the target condition for the treatment. This phase tests how well the treatment works at different doses and what side effects occur.

Phase 3 involves a much larger group of volunteers, from several hundred to a few thousand, and provides the evidence needed to get regulatory approval to market the drug or treatment. This phase tests whether the treatment is safe and how well it works compared to an existing treatment - sometimes referred to as ‘the gold standard’ - or to a placebo. A placebo is a substance that has no therapeutic effect, and is used as a control in testing new medications.

Phase 4 clinical trials involve thousands of participants and collect safety information once the medication has been approved and is being used in the market. It is often during phase 4 that rare and sometimes serious side effects might be reported. The information from phase 3 and phase 4 trials inform the side-effect profile that appears on the packaging information accompanying the treatment.

Why is it challenging to get people involved?

Recruitment into trials can be challenging for many reasons5, including:

  • Doctors may not know about the research and therefore don’t tell their patients;
  • There is a general lack of awareness about clinical trials;
  • Advertisements for recruits are not seen by the right people;
  • Study protocols are very complex and therefore not well understood, or they are too burdensome or require invasive procedures;
  • People are busy and may not have time to take part (all trials require different levels of participation);
  • People may be fearful or may not understand what is required, or their family members may not support their participation;
  • The study requirements may not be culturally sensitive.

Why is it so important to get people to participate in clinical trials?

At some point, all of us will need to take medication or will have a family member who needs treatment for a medical condition. Best-practice treatments and new medications can only result from successful clinical trials, and clinical trials need people to participate.

A huge proportion of clinical trials - up to 80% - fail to meet their recruitment target. This means they don’t have enough people participating in them and therefore they may not have enough statistical power to answer the question they are designed to answer. Not having enough people involved in clinical trials means new discoveries take longer.

See all the trials underway at The George Institute for Global Health