Retrospective Study Suggests New Approaches to Improve Diverse Clinical Trial Enrollment

Using real-world disease epidemiology data rather than the conventional standard of US Census data may be a better benchmark for ensuring that clinical trial enrollment reflects the populations most affected by diseases, according to the results of a 17-year retrospective study examining clinical trial diversity.

Specifically, the study investigated the historical representation of US-based participants in GSK clinical trials. Investigators looked at clinical trial demographic data from 495 GSK and ViiV clinical trials involving US-based participants between 2002 and 2019.

According to the study, the results will inform how GSK and potentially other clinical trial sponsors can better design research to represent the diversity of real-world patient populations, given that some racial and ethnic groups are disproportionately affected by some diseases. The safety and efficacy of treatments can also vary based on genetic or environmental factors, and appropriate representation in clinical research is crucial for advancing the understanding of new medicines and vaccines.

“GSK is committed to ensuring our clinical trials reflect the diverse demographics of the patients impacted by the disease under study, given the disproportional impact some diseases may have on specific patient groups,” said Christopher Corsico, senior vice president of development at GSK, in a press release.

US Census Bureau data do not necessarily reflect the proportion of the population by ethnicity that may be impacted by specific diseases, according to the study. The findings confirmed that in asthma, chronic obstructive pulmonary disease (COPD), HIV, and influenza, census data differed from the epidemiological data.

For example, although US Census Bureau data indicate that just 13.4% of the total population is Black or African American, the data also say that 17% of all patients with asthma, 7.1% of patients with COPD, 55.3% of those with HIV, and 23.7% of patients with influenza are Black or African American. Additionally, US Census Bureau data indicate that 18.5% of the population is Hispanic or Latinx, while the proportion of the US population who have each disease and who are Hispanic or Latinx is 14.4% for asthma, 6.5% for COPD, 35.7% for HIV, and 10.4% for influenza.

The study findings also showed that GSK trial enrollment for each condition differed by race and ethnicity. For example, enrollment in clinical trials of Black or African Americans for asthma (22.6%) exceeded both census (13.4%) and epidemiologic (17%) levels. In HIV trials, enrollment of Black or African Americans at 35.1% significantly exceeded census levels of 13.4% but underrepresented epidemiologic levels of 55.3%.

According to the press release, 100% of GSK’s phase 3 trials had a diversity plan in place by the end of 2022 to enroll the groups most affected by the disease being studied, as based on epidemiology data. The company is also working with patient advocacy groups and academic organizations to tackle the barriers that negatively impact clinical trial turnout of certain patient populations, such as access to transportation, language barriers, lack of trust, and awareness.

One strategy that GSK is employing to address these barriers is rolling out global cultural competency training to approximately 15,000 clinical trial staff members. The trainings give staff members the tools to engage with diverse communities and advocacy groups to build trust, enhance disease awareness, and provide appropriately tailored information, according to GSK.

GSK is currently evaluating retrospective clinical trial demographic data for past participants who were enrolled in other countries around the world.

“While we have more to do at GSK, today’s publication offers important new data and analyses for sponsors to consider when planning their clinical programs,” Corsico said in the press release. “To make meaningful progress on diverse participation in clinical trials, we need meaningful collaboration with regulators, patients, academia, other biopharma companies, and the wider health care ecosystem so that together we can achieve a shared goal of better health outcomes for all.”

REFERENCE

GSK announces results from 17-year retrospective study on US clinical trial diversity. News release. GSK; February 6, 2023. Accessed February 10, 2023. https://www.gsk.com/en-gb/media/press-releases/gsk-announces-results-from-17-year-retrospective-study-on-us-clinical-trial-diversity/