PURPOSE

Participating in phase I cancer clinical trials often entails extra visits and procedures. We describe the planned time and procedures associated with phase I trial participation.

METHODS

We searched ClinicalTrials.gov for phase I cancer trials of new drugs with assessment schedules and results posted between 2020 and 2022. Trials were included if participants had advanced or metastatic disease. Our primary analysis measured the number of planned research days (PRDs; each day a clinic visit is required) per participant up to the first month of trial participation and for the entire trial duration. Secondarily, we estimated the number of research procedures.

RESULTS

Our sample included 71 phase I trials comprising 302 cohorts. These trials enrolled 3,904 participants; the median participation duration was 2.5 months. During screening and up to the first month of participation, the median PRDs per participant was 7 (IQR, 7-10). Across the entire trial, the median PRDs per participant was 4.5 days per month (IQR, 3.30-6.20). Participants spent 15% of trial days attending planned appointments. Per trial cohort, participants were given a median of 8 (IQR, 7-11) physical examinations, 6 (IQR, 3-10) infusions, 6 (IQR, 3-12) electrocardiograms, and 1 (IQR, 1-3) biopsy.

CONCLUSION

Participants commit a substantial amount of time to planned visits in phase I cancer trials, especially in the first month. Overall, they invest 15% of trial days attending planned research activities. These estimates provide a lower bound to the time participants in phase I trials donate to drug development, as our analysis excluded unplanned visits.