Durga Borkar, MD: Trial Eligibility Race Issues for Treatment Naïve Diabetic Macular Edema

Credit: Duke University School of Medicine

A hemoglobin A1C criteria of < 10 restricts the eligibility of Black patients with treatment naïve diabetic macular edema more so than White patients, according to a new study.

The study sought to understand how restricting inclusion and exclusion criteria of clinical trials for participants with diabetic macular edema impacts a race’s eligibility for a clinical trial. For instance, one criterion required hemoglobin A1C levels to be 10 or under.

Durga Borkar, MD, MMCi from the Duke Eye Center at Duke University of Medicine, presented the study at 127th Annual American Academy of Ophthalmology (AAO) conference in San Francisco, California. In an interview with HCPLive, Borkar spoke about her team’s findings.

“We know that increasing diversity in clinical trials remains a goal [in] ophthalmology, particularly in areas that evaluate chronic disease, such as diabetes and glaucoma,” Borkar said. “This study suggests that one of the ways that we may potentially increase diversity in clinical trials is by taking a closer look at our inclusion and exclusion criteria and the differential impacts they may have on certain populations and to do this step before a clinical trial even starts.”

The investigators found participants with a new diabetic macular edema diagnosis from January 1, 2022 – June 30, 2022 on the Optum database. The team excluded participants if they had < 2 years of “continuous enrollment before the index date” (n = 215,457), previous anti-VEGF treatment or focal laser (n = 54,348), previous diseases that could be confused with diabetic macular edema (such as retinal occlusion) (n = 41,260), and no documented race (n = 741). The criteria excluded 350,314 individuals, and 12,782 individuals ended up participating in the study.

From there, the investigators studied a race breakdown and found a high number of White participants. Of the eligible participants, 6864 were White, 2327 were Black, 2904 were Hispanic, and 688 were Asian.

Borkar said the phase 3 diabetic macular required A1C criteria of < 12 or <10. After examining A1C criteria < 10 for each race, the investigators found there were 87.8% White (n = 6024) (P < .001), 81.9% Black (n = 1906) (P <.001), 82.4% Hispanic (n = 2393) (P <.001, and 90.4% Asian (n = 622) (P = .04).

In a poster abstract of the study, Borkar and collogues wrote how they most likely understated the impact of inclusion and exclusion criteria related to disease control since the study focused solely on patients with insurance. All participants had insurance since the investigators retrieved their data from the Optum database. Borkar theorized if the team had looked at a larger database including uninsured patients, there might be a larger impact of A1C criteria restricting patients.

Moreover, Borkar discussed minority groups—particularly African Americans—lack of access to clinical trials. Previous geographic studies, such as examining the retina, had explored this topic. For future research, Borkar believes it is important to study the impact of every criteria on the eligible population—and study the impact through a race and socioeconomic status angle to not exclude any race or ethnicity.

“I think that the eligibility criteria is just one part of the puzzle here—there’s likely a number of factors that come into play,” Borkar said. “I think there’s historical and cultural factors that impact patients’ willingness to participate in trials, and those need to be evaluated and addressed.”

References

^{Borkar, Durga. Understanding the Impact of HbA1c Thresholds on DME Clinical Trial Eligibility by Race. Presented at the 2023 American Academy of Ophthalmology Annual Meeting, November 3 – 6, 2023.}