Transgender people in clinical trials of drugs and biologics: An analysis of ClinicalTrials.gov from 2007 to 2023.

AIMS: Transgender people have unmet health needs related to chronic conditions such as dementia, osteoporosis and hypertension. Community-driven advocacy increased transgender representation in phase III trials for pharmacological prevention of HIV, but the extent to which drug trials for other conditions have included transgender people is unknown. We investigated the extent to which trials of drugs and biologics represented transgender people across therapeutic areas on ClinicalTrials.gov.

METHODS: Cross-sectional analysis of trials of drugs and biologics registered on ClinicalTrials.gov from 2007-2023. We included efficacy and effectiveness trials (phase II-IV) with transgender-related terms (e.g. 'transgend*'). We labelled trials as Inclusive or Exclusive of transgender people using the trial eligibility criteria. We compared trials (therapeutic area, trial design, enrolment), summarized trials registered from 2008 onward and characterized participant enrolment for Inclusive trials with primary trial publications. We summarized continuous data using median (range), categorical data using frequencies and percentages and compared trial characteristics using Fisher's exact test.

RESULTS: Ninety-seven trials represented transgender people. Characteristics were similar between 85 Inclusive and 12 Exclusive trials. Among Inclusive trials, 58% focused on infectious diseases (e.g. treatment or prevention of HIV and COVID-19), 15% on mental health (e.g. post-traumatic stress disorder, substance use-related disorders), and the remainder focused on endocrine (9%), pain (5%), digestive system disorders (1%) and neoplasms (1%). Twenty (of 25) trials reported enrolment of transgender participants in primary trial publications or reported results.

CONCLUSION: Transgender-inclusive trials have increased since 2008. Most trials focused on infectious diseases and mental health. Investigators should increase opportunities to include of transgender people in trials of drugs and biologics for chronic diseases.