NCT04726241 2026-05-05The Pediatric Acute Leukemia (PedAL) Screening Trial - A Study to Test Bone Marrow and Blood in Children With Leukemia That Has Come Back After Treatment or Is Difficult to Treat - A Leukemia & Lymphoma Society and Children's Oncology Group StudyPedAL BCU, LLCPhase 1/2 Recruiting960 enrolled