Diversity in clinical trials has been the focus of numerous industry discussions in recent years. This is for good reason, since underrepresentation amongst participants is hindering the industry’s ability to understand the full safety and efficacy profile of novel therapeutics, creating limited empirical evidence with questionable generalizability.
This can have serious consequences for misrepresented patient subgroups, including restricted or delayed access to medical interventions. In 2019, the US Food and Drug Administration’s (FDA) decision to exclude cisgender women from an approved HIV intervention because of the sponsor’s failure to investigate its effects in females is a good example of the ramifications that underrepresentation in research can have.
GlobalData’s Clinical Trials database reveals that 18.7% of clinical trial participants in US-based studies identified themselves as Black/African American between 2017 and 2024. However, representation amongst other racial minorities such as Native American (0.7%), Native Hawaiian/Pacific Islander (0.3%), and Asian (4.8%) has been very low. This analysis was restricted to studies where the diversity data was available. As such, underrepresentation could be more extreme since only around 38% of North American trials disclose participants’ racial data.
Breaking down the results even further by trial phase and therapy area, key areas of concern can be identified. Minority representation appears to be lacking most significantly in Phases II and III, where White participants make up almost three quarters of those enrolled. Representing the largest stage of clinical trials, Phase III is where the widest representation is generally expected, and while Black/African American participants make up 19% of those enrolled in US Phase III trials, Asian and Native American participants account for just 3% and 1% respectively.
Moreover, examining the data by five key therapy areas, it is clear that a lack of diversity continues to plague US oncology trials, where 77% of participants enrolled in studies from 2017-2024 identified as White.
A shifting landscape
While the figures indicate a lot of work must be done to improve minority representation in clinical research, the industry is increasingly focused on addressing this. In fact, since 2017, the number of times pharmaceutical sponsors have mentioned the phrase ‘diversity in clinical trials’ in their company filings has increased by 300%, reflecting increasing awareness of the problem and a growing commitment to improving it. This trend has been particularly strong in the states, with US-headquartered companies accounting for 69% of mentions in 2023.
Regulations are also catching up. The FDA has been spotlighting the importance of diversity for a while now; in 2020, the agency released its final guidance on Enhancing the Diversity of Clinical Trial Populations — Eligibility Criteria, Enrollment Practices, and Trial Designs. This provided recommendations for how sponsors can increase the number of people they enroll from underrepresented groups, including steps such as broadening eligibility requirements and community engagement activities.
In 2024, things stepped up when the FDA released a draft guidance, Diversity Plans to Improve Enrollment of Participants from Underrepresented Racial and Ethnic Populations in Clinical Trials, as part of the Federal Drug and Omnibus Reform Act (FDORA). Under this new regulation,sponsors are now required to submit a Diversity Action Plan (DAP) for certain clinical studies. The DAP should include the enrollment goals for the study, the rationale for the study’s enrollment goals, and the concrete actions that the sponsor will take in order to achieve those diversity targets. One key point is that enrollment numbers should be representative of the patient population affected by the therapeutic indication. If a disease predominantly affects patients of a certain demographic, for instance, this must now be reflected in the study’s participant population. Specific targets have not been included, however.
According to Kris Booth, Director of Strategic Partnerships at EmVenio Research, a PCM Trials company, this guidance is widely regarded as an “initial step towards seeing how diversity can grow within clinical trials.” He believes protocol designs and data analyses will be under greater scrutiny as a result, and that regulatory action could certainly come into play in the future.
Retention: The heart of the diversity issue
Despite the updated guidance, there are many obstacles to overcome if the industry is to fully operationalize its diversity goals. Potential roadblocks include a lack of clarity within regulatory frameworks, communication issues with trial sites, a historic lack of trust from previously marginalized groups, and geographical barriers – all adding to the challenge. When relying solely on the traditional brick-and-mortar site network in the US, for example, trials are unlikely to reach research-naïve patients, like those living in rural areas.
While the conversation around diversity in clinical trials tends to revolve around the need for more targeted recruitment amongst diverse groups, it is equally important to ensure those participants are able to remain in the study throughout its entirety. The issue here is that many trial designs (which frequently involve an extended follow-up period with visits to the trial site) can become overly burdensome, especially because trial sites are often located a considerable distance from participants’ homes. This burden is problematic for participants of all backgrounds but can have particularly detrimental effects amongst diverse groups, meaning logistical barriers have historically led to higher dropout rates amongst marginalized participants.
This is why the FDA’s latest diversity guidance is frequently studied alongside its previous recommendations on decentralized, or community-based trials, which aim to break down logistical and geographical-related barriers by bringing trial activities closer to participants. To do so calls for the implementation of alternative strategies such as local community-based sites and mobile visits, requiring partnerships with community research providers such as PCM Trials, who has been supporting alternative clinical trial access models since 2008.
Reaching for change
In March 2024, PCM Trials announced its acquisition of EmVenio Research, bringing together two companies whose key purpose is to expand the reach of the traditional clinical trial network by leveraging local community settings such as clinics, mobile sites, and participants’ homes. The aim is to make trial participation easier on people of all backgrounds and therefore improve the recruitment and retention of underrepresented groups in research.
The companies’ strategies are working. 44.7% of EmVenio’s participants self-identified as a minority ethnicity in the company’s completed studies, and previous research around mobile visits has highlighted its ability to boost enrollment of underrepresented populations such as Native American, Black/African American, and Native Hawaiian/Pacific Islander.
“The combined idea here is about reach,” says Booth. “It’s about meeting these research participants where they are in their life journey, in their medical journey, in their treatment journey, as well as in their geographic locations.”
As Stephenie Hitchcock, Director of Project Management at PCM Trials explains, this can include bringing clinical trial activities directly to participants through mobile visit services, which can support a wide range of clinical trial procedures.
“Conducting those protocol-specific activities [at the participant’s location] enables the trial to collect all of that data which is then sent back to the site,” says Hitchcock. “The clinicians conducting the mobile visit are an extension of the site.”
Community research sites, as provided by EmVenio Research in the US, operate quite differently. The company establishes these sites in carefully chosen locations by studying factors such as population demographics, existing clinical trial access, health risk metrics, and disease prevalence. Whether it’s a mobile research site or a research center set up within existing healthcare facilities, they operate as a traditional site within the community, enabling the team to engage closely with local organizations and community leaders to help raise awareness of research opportunities and establish trust among potential participants.
This multi-pronged approach unlocks a world where participants have options for how they wish to take part in a study – and with a wider range of participation models comes the possibility to cater to more demographics, ensuring trials are more accessible for diverse groups.
“By bringing the visits to the participants through a partnership with PCM Trials to implement mobile visits, or by employing community research sites by partnering with EmVenio Research, we can ensure that we are offering patients flexibility,” says Hitchcock. “Clinical trials are not one-size-fits-all; we really need to adapt for these different populations.”
There could be a long road ahead when it comes to diversity in clinical trials since breaking down barriers of mistrust cannot be accomplished overnight. However, by embracing community research methodologies and thinking a little differently about what it could take to raise awareness and improve recruitment and retention levels amongst underrepresented populations, the industry can get one step closer to solving research bias in clinical trials.