Incorporating transgender and nonbinary participants in phase 1 clinical drug trials: Current knowledge gaps and considerations.

Phase 1 clinical drug trials critically depend on the participation of healthy volunteers to evaluate the safety and pharmacokinetics of new medicinal products. Current selection criteria and health definitions often overlook the unique health profiles of transgender and nonbinary individuals, potentially excluding them from participating in these essential early-stage studies. This review aims to identify and discuss current knowledge gaps and considerations regarding the inclusion of transgender and nonbinary participants in phase 1 clinical drug trials.