Characterization and outcomes of patients enrolled to multiple phase I cancer trials

Abstract

Purpose Some patients who participate in early phase cancer trials enroll to more than one trial. Whether these patients have different characteristics or outcomes than patients who enroll to a single phase I trial is unknown. Methods The study included all patients who participated in the solid tumor drug development program of the Princess Margaret Cancer Centre, a specialized academic cancer center, from July 2014 to January 2017. Patients sequentially enrolled to multiple phase I trials were compared to those enrolled in a single trial according to demographics, clinical characteristics, reported toxicities and prognosis. Results The study cohort included 328 patients, including 61 (19%) enrolled to multiple phase I trials and 267 (81%) enrolled to a single phase I trial. Demographics, comorbidities, performance status, cancer site and time between initial diagnosis and initial enrollment to the phase I program were comparable between both groups. Patients enrolled to multiple phase I trials received more previous non-trial treatment lines (median 3 versus 2, p \u2009<\u20090.001) and had a higher average response rate on phase I trials (18% versus 10%, p \u2009=\u20090.03). Toxicity data, including number of any adverse events (AEs), grade 3/4 AEs, serious AEs and dose-limiting toxicities were comparable between both groups. Time to disease progression and time to last documented follow-up were also comparable between both groups. Conclusions Patients enrolled to multiple phase I trials and those enrolled to a single trial had similar toxicity and prognostic profiles. These patients do not introduce bias into early-phase cancer trials results.