Eligibility criteria and clinical trials: An FDA perspective

Randomized clinical trials are regarded as the gold standard for evaluating the effectiveness and safety of interventions. The US Food and Drug Administration (FDA) has made efforts to promote inclusive eligibility criteria. The objective of this study is to identify common trends in eligibility criteria and identify patterns of exclusion criteria among different diseases.

The authors evaluated the inclusion and exclusion criteria of 38 pivotal clinical trials representing 38 novel drugs approved between 2014 and 2017. Additionally, the authors reviewed the demographic characteristics of participants enrolled across 38 trials.

Eighty two percent of trials in our study excluded participants based on hepatic related criteria and 79% trials excluded participants based on renal related criteria and specific infectious diseases. For trials in conditions that affected both men and women, there were no exclusions based on gender and race. More than 90% of trials excluded pregnant, lactating women and women not on adequate contraception. Of the 36,644 patients enrolled in trials for which both men and women were eligible, 62% were men.

The most frequent exclusion criteria were pregnancy, lactation/breastfeeding, renal and hepatic abnormalities, and specific infectious diseases. The preponderance of men in our study likely indicates that factors other than exclusion criteria affect enrollment. The lower representation of women may have been influenced by two large cardiovascular trials that included 75% men. Our study marks an important step in the ongoing efforts of the Agency to increase inclusivity in clinical trials by understanding common clinical trial eligibility criteria patterns.