Screen failures in clinical trials in retina

Abstract

Purpose : Disparities in clinical trials are a major problem due to significant underrepresentation of certain gender, racial and ethnic groups. Several factors including stringent protocol criteria selection, recruitment methods, and regional site demographics hinder our understanding of retinal diseases. We performed a cross sectional study to describe differences in patient profiles and various causes of screen failures in clinical trials

Methods : Screening data of 87 trials from 6 centers were analyzed. Study characteristics (disease studied, phase of trial, route of drug administration) and patient demographics (age, gender, race, ethnicity, and employment status) were compared among different causes of screen failures. Screen failures were broadly classified into 4 categories: study criteria, patient related, physician related and miscellaneous. Pearson Chi-square test and ANOVA were used for statistical analysis.

Results : Among 87 trials and 962 patients, 464 (48.2%) were successfully randomized and 498 (51.8%) patients were classified as screen failures. Mean age (SD) was 76.5 (10.44) years and 59.5% were females. Trial disease states included Diabetic Macular Edema (DME, n=44), dry Age-related Macular Degeneration (AMD, n=18), wet AMD (n=18), Vascular occlusions (n=4), macular telangiectasia (n=2) and proliferative vitreoretinopathy related retinal detachments (n=1). Predominantly whites (93%) and unemployed/retired patients (66%) were screened. Of the 498 screen failures, most were due to study inclusion/exclusion criteria (n=400 [80%]) followed by patient related (n=35 [7%]), physician related (n=28 [5.6%]) and miscellaneous reasons (n=6 [1.2%]). Reason for screen failure was not available for 27 (5.4%) patients. Among 20 specific reasons for screen failure, common reasons were ocular/imaging findings (n=219 [44%]) and visual acuity (n=73 [14.6%]) not within the inclusion criteria, and patients excluded due to a systemic comorbidity (n=45 [9.2%]).

Conclusions : Whites and unemployed/retired patients predominantly participated in retinal clinical trials. Screen failures in retina trials are commonly due to ocular/imaging findings and visual acuity not within the inclusion criteria. Screen failures incur significant costs and time without contributing valuable data to the study. Better recruitment strategies from diverse backgrounds and careful consideration of study criteria can aid in decreasing the rate of screen failures.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.