Introduction: Despite federal policies to foster equal representation of female and male participants, sex bias remains common in clinical trial enrollment, leading to underrepresentation of women among trial participants. The extent of sex bias in clinical trials in urology is not well characterized. This study aimed to evaluate enrollment rates by sex for clinical trials leading to new drug approvals in urology. Methods: We retrospectively reviewed the US Food and Drug Administration database for new drug approvals for urological indications from 2016 through 2021. Published trials that supported these approvals were analyzed to determine enrollment rates of female participants. The sample was grouped and analyzed by demographic and clinical variables. To assess sex bias, we defined a “sex-matching ratio” as the proportion of female to male trial enrollees, where a ratio of 1.0 would indicate equal numbers of women and men. A ratio =0.9 was considered “optimal” based on prior published studies. Results: Of a total of 20 trials supporting novel drugs in urology, 6 were excluded due to sex-specific conditions, leaving a total of 14 trials that enrolled 10,875 female and male participants. The clinical indications in the trials included urinary tract infection (4 trials, 29%), urothelial carcinoma (4 trials, 29%), renal cell carcinoma (1 trial,7%), and overactive bladder (1 trial, 7%). Women accounted for 43% of the total sample and had significantly less enrollment in trials for cancer indications; women were only 26% of enrollees in urothelial and renal cancer trials vs 45% in non-cancer trials (p < 0.001). Five trials (36%) enrolled more women than men overall; however, the participants in these majority-women trials (3,215) only comprised 30% of total enrolled sample. In terms of sex bias, 7 of the trials (50%) achieved an optimal sex-matching ratio =0.9. Among the other 7 trials with suboptimal sex-matching ratios, 1 trial had a ratio of 0.75, while the remaining 6 trials had ratios <0.5 (range 0.26-0.42), indicating that women accounted for less than half the number of men in these trials. The total enrollees in the 7 trials with suboptimal sex-matching ratios was 6,728; of these, women (1,962) accounted for just 29% of the sample. Conclusions: Sex bias is common in contemporary clinical trials for new drugs in urology. In half the trials with the strongest sex bias, women accounted for just 29% of the study population. Renewed efforts are urgently needed to ensure inclusive drug trials in urology. SOURCE OF Funding: None
