Contemporary Characteristics and Outcomes of Pediatric Oncology Patients Participating in Early Phase Clinical Trials

Phase 1 or phase 1/2 trials are a first step in pediatric cancer drug development. Currently, there is a paucity of information regarding contemporary outcomes for pediatric patients enrolled in these trials. We describe characteristics and outcomes of patients enrolled in pediatric phase 1 clinical trials over a 9-year period at a single institution.

We queried our clinical trials management system to generate a list of patients enrolled and treated on pediatric phase 1 or phase 1/2 trials from 2011 to 2019. We collected baseline demographics, clinical data, efficacy, and safety endpoints post-enrollment including: time to death, objective response to therapy, duration on therapy, need for dose modification, and occurrence of dose-limiting toxicity. Overall survival was calculated using Kaplan-Meier methods.

A total of 224 unique patients accounted for 259 enrollments and 242 treatment episodes. The median age at enrollment was 11 years (range 0-27 years) and 56.2% were male. The majority were White (85.7%) and Non-Hispanic (88.2%). English was the primary language for 86.3% of patients, and 54.9% had private insurance. Solid tumors were the most common malignancy (41.0%), followed by brain tumors (34.1%), and hematologic malignancies (24.9%). Among treatment episodes, 49.3% received targeted monotherapy. After first enrollment, 27.6% of patients had an objective response to therapy (52.9% for hematologic malignancies, 20.5% for brain tumors, and 15.8% for solid tumors). The median duration of therapy was 1.5 months. Median overall survival from first enrollment for 218 patients treated with available vital status was 13.1 months. Toxicity outcomes included 27 patients (11.2%) requiring dose modification and 22 patients (9.0%) having a DLT.

Overall survival is poor for patients in pediatric oncology early phase trials, despite approximately a quarter having an initial response. These data are informative for discussions between providers and families regarding outcomes after phase 1 trial participation.