Can Engagement Aid in Design and Accrual on Clinical Trials? Observations from Comparative Study of Proton and Photon Therapy in Prostate Cancer: A Prospective Comparison of Outcomes with Proton and Photon Radiation in Prostate Cancer

Purpose: Slow accrual has been problematic in many clinical trials, especially comparative studies of proton and photon radiation. In addition to proton facility limitations, issues of patient and institutional preferences may also affect trial accrual. We hypothesized that patient engagement could inform the design of a comparative trial with the potential for rapid and representative accrual. Previously, we detailed a patient engagement process that identified patient preferences for treatment outcomes and study design for a comparative study of proton and photon therapy in prostate cancer (COMPPARE). We tested the efficacy of this engagement process and herein report the resulting design of COMPPARE and its accrual outcomes. Methods and Materials: Based on patient engagement, COMPPARE was designed as a large prospective comparison of outcomes between parallel cohorts of prostate cancer patients treated pragmatically with protons or photons, with the goal of rapid, representative, and comparable proton therapy and intensity modulated radiation therapy accrual. Results: Site activation required a median of 18 months rather than the planned 6 months, and COVID-19 surges were associated with significant accrual depressions. However, 2524 patients treated with intensity modulated radiation therapy and proton therapy from 51 institutions were accrued in 52 months to COMPPARE, including 404 Black patients, comprising 16% of the study population, exceeding the goal of 10%. Conclusions: Despite unanticipated delays due to site activation and COVID-19 surges, rapid and representative accrual of the large COMPPARE cohorts suggests that a patient engagement process can be highly effective in designing a patient-centric clinical trial.