In clinical research, every data point comes from a person – and it matters who that person is. In fact, each person who enters a clinical trial contributes hundreds of data points to study. Large-scale clinical trials involving hundreds or even thousands of individuals are pivotal to the development of new drugs. But individuals respond to drugs differently. The more closely the test group represents the population affected by the disease in question, the more generalisable the results of the study are to the actual population who will receive the treatment once the product is approved.
Medicines have historically been tested on disproportionately White populations. Only after some drugs have been approved does it become clear that some of them, work less well for certain minority ethnic groups, such as drugs for high blood pressure.
The US government passed legislation in late 2022 requiring drug developers to devise clinical trial diversity plans for medicines under investigation, and some are already doing so. The European Medicines Agency has also updated its guidance to promote clinical trial diversity. But creating those plans is only the first step in achieving clinical trial diversity. Unconscious bias by clinicians and staff at trial sites, a lack of trust in the healthcare system and inadequate communications must also be addressed to achieve the aims of clinical diversity plans.
“Building trust within communities is a known driver of success in recruiting under-represented patients to clinical research; and if people feel seen, heard, and treated as important partners in research in their community, they’re more likely to be more trusting of clinical trials,” says Leslie Henderson-Williams, Director, Global Diversity & Inclusion for Clinical Trials, at health data and analytics specialist IQVIA.
Getting the details right
“Racial and ethnic diversity goals are more complex to set than the more established diversity metrics such as age and sex,” says Michel Reid, Senior Director and Head, Global Demographics and Diversity, at GSK. No two clinical trial diversity plans will look the same. Diseases affect different races and ethnicities differently. Heart disease, colorectal cancer and asthma, for instance, affect Black people in the US at higher rates than others. In the UK, people of South Asian heritage are at higher risk of cardiovascular disease than people from other ethnicities. In New Zealand, the prevalence of type 2 diabetes is around three times higher in Maori and Pacific populations than in their White counterparts. Many clinical trials run at sites around the world, and what counts as a diverse example in a place with a relatively homogenous population, such as Japan, will look very different from one in a more mixed country such as the UK. “We’re thinking down at a much more granular level,” says Reid.
Reid led an in-depth study of the racial and ethnic diversity of US-based participants in GSK and ViiV clinical trials reaching back almost two decades. That analysis helped identify disease areas and trial types that needed the most work in achieving diversity. The study also revealed that, in some cases, a trial could reflect the local census population but still fall short of representing the population affected by a disease, highlighting the importance of using disease-specific metrics to measure trial diversity. All of GSK’s phase three trials – the large-scale studies that are pivotal to a drug or vaccine’s approval – have a diversity plan in place.
To enrol in a clinical trial, a patient must first know about it. The first barrier to clinical trial diversity is bias that can affect clinicians’ choice of whom to invite to consider participation. Analysis of a US clinical trial examining bronchiolitis in children found that clinicians were less likely to invite Hispanic children into the trial than those of White ethnic backgrounds. A separate study has found that Hispanic children are at higher risk of severe bronchiolitis than White children. A survey of cancer clinical trial specialists in Australia revealed that language barriers during time-pressured consultations commonly meant that people from non-White backgrounds were not invited to participate in research.
Building trust
Trust is also central to participation: a patient must be certain they will receive good care and careful monitoring if they are to be among the first people to try a new drug or vaccine. Building trust is a multifaceted process. One way is through better communication about the benefits and risks of participating in clinical research. Another is by ensuring that the clinics, medical centres and other places that run clinical trials are staffed by relatable people. Clinical trial sites with a greater racial and ethnic mix in their workforces are also the most successful at attracting a diverse range of clinical trial participants.
Reid says GSK is working on all these fronts to smooth the way for more diverse clinical trial participation. The company takes diversity of staff into consideration when selecting clinical trial locations. It provides training on overcoming unconscious bias for the people who will be recruiting patients for studies. It also trains clinicians at trial sites in how to use language to make people feel respected. “You can’t just build these plans and hope people show up,” says Reid. “We have to do the work.”
New drug trials wouldn’t happen without scientific breakthroughs, and efforts are also under way to diversify the scientists who work on medical innovations. Black and Hispanic people, women and those from socioeconomically disadvantaged backgrounds are among groups that are under-represented in the scientific workforce, and yet research shows that scientific papers with more diverse groups of authors produce higher-impact findings. “There’s no point in innovating for just one part of society,” says Anne-Marie Imafidon, Chief Executive of Stemettes, a UK organisation that works to increase the participation of girls and young women, especially those from minority ethnic backgrounds, in science. “We're talking about data sets, but also talking about who is making decisions on priorities,” she adds.
Clinical trials that properly represent the people who will ultimately benefit from a drug are not just more inclusive, they are better science. They will enable drug developers to gain a better overall picture of how well their treatments work, as well as identify side effects that might affect only some groups. Diversity goals are only the first step, and it will take time to achieve their aims, but the result will be better healthcare for more people.
