Patient access to clinical trials is a fundamental aspect of drug development, particularly phase 1 oncology trials recruiting patients with advanced cancers. Adequate representation of both male and female patients in early phase trials is necessary to determine the impact of gender on safety, pharmacokinetics, and other parameters evaluated. Underrepresentation of women in oncology clinical research has been demonstrated in the past. We sought to determine whether a similar trend exists in phase 1 clinical trials.
All phase 1 trials published in the Journal of Clinical Oncology (JCO) between 2010 – 2018 were reviewed and the following parameters determined: patient population; total number of participants; number and percentage of Male and Female participants. To ensure reliability, two independent reviews were conducted. This abstract focused on the subset of studies targeting a population of adult and pediatric non-tumor specific advanced cancer patients with no treatment options for their disease. The expected representation of male and female patients within this population was assumed to be 1:1. The absolute difference in percentage between 50% and the observed percentage of patients who were male and female was calculated.
73 phase 1 clinical trials were published in JCO reviewed including 3,855 patients. 4 trials did not report the male/female distribution and were excluded from the analysis. 27 (37%) studies were conducted in a population of advanced cancer patient, including 1,719 patients. The average absolute percentage difference between the expected and observed population was +2% for the male population and -4% for the female population. Wilcox Signed Rank Test demonstrated borderline statistical significance of this result (0=0.058).
Based on a cohort of 27 phase 1 studies published in JCO, it appears that underrepresentation of women in oncology clinical trials extends to phase 1 clinical development. It may be necessary for oncology phase 1 protocols to address the issue of adequate gender representation within the patient population enrolled. Attention should be given to identifying the barriers for women participation in trials to ensure adequate patient access, and representation in this critical stage of drug development.
Clinical trial identification
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All authors have declared no conflicts of interest.