Randomized Phase III Trial Compares Two Chemotherapy Regimens for Pediatric Brain Tumors Before Stem Cell Transplant

Supratentorial primitive neuroectodermal tumors (PNETs) and high-risk medulloblastoma are aggressive pediatric brain cancers requiring intensive treatment. Current therapeutic strategies often involve combination chemotherapy followed by high-dose chemotherapy with peripheral blood stem cell rescue. However, the optimal combination chemotherapy regimen administered prior to stem cell transplant remains undefined. Identifying the most effective initial chemotherapy approach is crucial for improving outcomes and minimizing toxicity in these vulnerable young patients, addressing a significant gap in current pediatric oncology protocols.

This randomized Phase III trial is designed to evaluate the comparative efficacy of two distinct combination chemotherapy regimens. The study enrolls young patients, specifically those aged >12 months and ≤21 years, who have been newly diagnosed with either supratentorial primitive neuroectodermal tumors or high-risk medulloblastoma. Patients are randomized to receive one of the two investigational chemotherapy regimens. The primary objective is to assess which regimen performs better when administered prior to subsequent intense chemotherapy and peripheral blood stem cell rescue, aiming to identify a superior pre-transplant induction strategy.

This abstract describes the design and rationale for an ongoing randomized Phase III clinical trial. Specific findings regarding the comparative efficacy of the two combination chemotherapy regimens are not yet available as the study aims to determine which regimen is more effective. The trial's primary goal is to establish whether one investigational regimen offers superior outcomes in young patients with supratentorial primitive neuroectodermal tumors or high-risk medulloblastoma when used as pre-transplant induction therapy. Therefore, no quantitative results, p-values, or fold-changes can be reported at this stage.