Racial, Ethnic Disparities Seen in Ophthalmology Drug Trials, Study Says

Blacks and Hispanics were underrepresented in relation to their US racial distribution in clinical trials for ophthalmology drug approvals from 2000 to 2020, a new report shows, although some trends began to narrow during the later years of the study, according to a recent report in JAMA Ophthalmology.

Still, the ratios are expected to worsen by 2050, with White participants increasingly overrepresented and Blacks and Hispanics increasingly underrepresented.

Results showed predicted enrollment incidence ratios for 3 diseases: neovascular age-related macular degeneration (AMD), diabetic retinopathy (DR), and open-angle glaucoma (OAG). The enrollment incidence ratio is a measure of disparity, representing the proportion of patients of a particular race/ethnicity among trial participants divided by the estimated proportion of patients of that race who received a diagnosis of a specific condition among the US population.

For AMD, results were 1.08 for Whites vs. 0.04 for Blacks and 0.77 Hispanics; for DR it was 1.83 vs 0.87 vs 0.59, and for open-angle glaucoma, it was 1.62 vs 0.90 vs 0.37.

“Although there was meaningful improvement from 2000 to 2020, further efforts to increase minority enrollment in clinical trials seem to be warranted,” wrote the authors, all from Vanderbilt University medical institutions in Nashville, Tenn.

Enrollment disparity was found after accounting for expected disease prevalence. For example, approximately 89% of US persons with AMD identified as White and at least 4% as Black. However, over the past 20 years, Black comprised only 0.177% of trial participants.

Given that African American individuals may be disproportionately affected by surgically treatable or preventable causes of blindness, such as cataract, glaucoma, [or] DR, it is critical to promote equitable participation in trials for emerging therapeutics,” the authors said.

Many studies have identified racial/ethnic differences, but none had the kinds of samples that were representative of the United States subpopulations, hindering efforts to establish their significance for those groups, according to the authors. In 2012, the FDA specifically addressed inclusion of demographic subgroups in clinical trials, followed by the National Institutes of Health for phase 3 trials in 2017. Despite those efforts, only 43% of manuscripts in ophthalmology journals in 2019 included data on race and/or ethnicity.

The new study encompassed 31 clinical trials of drugs for the 3 diseases, involving 13 medications and 18,410 participants.

Largely, the underrepresentation for racial-ethnic groups improved from the levels in trials in the first decade (2000-2010) compared with the second (2011-2020). There were increases in enrollment of Asian (odds ratio [OR], 2.30; 95% CI, 1.97-2.68; P < .001) and Hispanic participants (OR, 1.74; 95% CI, 1.49-2.03; P < .001) for AMD, Asian participants (OR, 2.21; 95% CI, 1.46-3.42; P < .001) for DR, and Black (OR, 1.60; 95% CI, 1.43-1.78; P < .001) and Hispanic participants (OR, 10.31; 95% CI, 8.05-13.35; P < .001) for OAG.

There was, however, a decrease in Black participants in DR trials (OR, 0.58; 95% CI, 0.42-0.79; P < .001) and no change in their level of participation in AMD trials.

The findings on disparities in the study are not unique. They are similar to findings in oncology, rhinology, neurology, dermatology, and cardiothoracic surgery, the authors noted. Also in ophthalmology, a recent review of sex and ethnicity found that trials of new molecular entities predominantly had women and Whites as enrollees.

Barriers to enrollment include financial resources, transportation, and employment, the authors noted. Low trust in the health care system and insufficient health literacy are other critical factors.

In addition, participants identified as Hispanic were often not identified or went unreported in many studies. The increased proportion of Hispanics in later trials of medications for AMD and OAG may have been a matter of accurately identifying and counting them, the authors said.

Reference

Berkowitz ST, Groth SL, Gangaputra S, et al. Racial/ethnic disparities in ophthalmology clinical trials resulting in US food and drug administration drug approvals from 2000 to 2020. JAMA Ophthalmol. Published online April 22, 2021. doi:10.1001/jamaophthalmol.2021.0857