Characteristics and Outcome of Pediatric Patients Enrolled in Phase I Oncology Trials

Abstract

Abstract Learning Objectives After completing this course, the reader will be able to: Describe the characteristics of pediatric patients who have enrolled in phase I trials over the past decade.Describe the relationship between enrollment characteristics and the risk for toxicity in a phase I trial.Identify the potential risks and benefits for pediatric patients with refractory solid tumors in phase I trials. CME This article is available for continuing medical education credit at CME.TheOncologist.com Purpose. To describe the characteristics of pediatric subjects who enroll in phase I trials, to determine the associations between pre-enrollment characteristics and the risk for toxicity, and to analyze response and survival outcomes. Experimental Design. Pre-enrollment characteristics and study outcomes were retrospectively analyzed for children with refractory solid tumors treated in one of 16 phase I trials with similar eligibility criteria at the National Cancer Institute between 1992 and 2005. Results. The 262 subjects analyzed had received a median of two (range, 0–9) prior chemotherapy regimens, and were on one (range, 0–12) concomitant medication. The Eastern Cooperative Oncology Group performance status scores for subjects were 0 (29%), 1 (48%), and 2 (19%); 19% had received a prior stem cell transplantation and 73% had received prior radiation. Approximately 90% of subjects were evaluable for the primary trial endpoints (toxicity and pharmacokinetics). Seventeen percent of subjects experienced a dose-limiting toxicity (DLT), 5% discontinued the study drug because of toxicity, and a drug-related death occurred in one subject (0.4%). Variables associated with a higher risk for developing a DLT, by multiple logistic regression analysis, were drug dose and prior radiation, for myelosuppressive agents, and drug dose and performance status, for nonmyelosuppressive agents. The complete and partial response rate was 4%; however, 17% of subjects had stable disease (received three or more cycles). The median overall survival time from the time of enrollment was five months. Conclusions. Primary trial objectives are achieved in approximately 90% of subjects with the standard phase I trial design and eligibility criteria despite the intensification of frontline and salvage therapies in pediatric subjects with cancer.