Gender disparity in enrollment in clinical trials for hairy cell leukemia (HCL) in the last 40 years.

Abstract

e19024 Background: Hairy Cell Leukemia (HCL) is a B-cell lymphoproliferative disorder characterized by infiltration of the bone marrow, liver, and spleen by malignant B cells with hairy cell cytoplasmic projections(1). There is a significant predominance of HCL in males, with a male-to-female ratio of 4:1, especially in Western countries. Differences have been found in the role of gender influencing the severity of the disease. The latest data had identified better outcomes in females with HCL(2). In the last 40 years of HCL research a distinct gender participation gap has surfaced, favoring males in the enrollment of clinical trials. Our study aims to investigate the contributing factors to this imbalance, such as physio-pathological reasons, socio-demographic characteristics, accessibility barriers, and awareness limitations. Methods: In this descriptive, retrospective study, we searched EMBASE, PUBMED, and ClinicalTrials.gov from January 1983 to December of 2023 for publications on randomized clinical trials (RCT) in Hairy Cell Leukemia. The number of participants in clinical trials, their gender, the country where the trial was conducted, year of publication was recorded and descriptive statistical analysis of all the variables was performed. Results: We identified 57 studies comprising 4595 individuals with different subtypes of HCL. Of the total RCT, 79.10% of the patients were male and 20.89% were female. 49.12% of the studies were performed in the United States, 38.59% in Western Europe, 5.26% in Eastern Europe, and the remaining in Japan, Australia, and Iran. 36.84% of RCT were performed between 2000 and 2010. The male-to-female ratio was 7.92 for RTC performed between 1983 to 1989, 3.81 for RCT performed between 1991 to 1999 and 3.36 for RCT performed between 2000 and 2010. Conclusions: Female patients with HCL were recently shown to have a significantly longer progression free survival than male patients. Our retrospective analysis confirms that there is smaller than expected percentage of female participants enrolled in HCL clinical trials published over the last four decades. When examining the male-to-female ratio over different time periods there was a notable decrease from RCTs performed in the 1980s compared to RTCs performed after 2000. The gender disparity observed in clinical trials where males may be overrepresented could be attributed to the predominantly higher prevalence of both newly diagnosed and relapsed HCL in males, making them more likely to be eligible for the RCT. Bridging this gender gap in trials is crucial to accurately reflect the efficacy of novel therapies in both males and females, enabling improved treatment design and better outcomes for all.