A Prospective Trial of Dalbavancin-Based Prophylaxis in Children and Adolescents With High-Risk Leukemia

This is a single-arm pilot clinical trial evaluating dalbavancin-based prophylaxis in children and adolescents with acute myeloid leukemia or relapsed lymphoblastic leukemia receiving myelosuppressive chemotherapy. Primary objective: \- To estimate the rate of bacterial bloodstream infection in pediatric patients with AML or relapsed ALL undergoing chemotherapy receiving dalbavancin-based prophylaxis Secondary objectives: * To describe the population pharmacokinetics of every 28 days dalbavancin up to 12 weeks in pediatric patients with AML or relapsed ALL undergoing chemotherapy * To describe the tolerability of every 28 days dalbavancin prophylaxis in pediatric patients with AML or relapsed ALL undergoing chemotherapy * To describe the acceptability of every 28 days dalbavancin prophylaxis in pediatric patients with AML or relapsed ALL undergoing chemotherapy * To estimate the rates of likely bacterial infections, Clostridioides difficile infection, and febrile neutropenia in pediatric patients receiving dalbavancin-based prophylaxis

Inclusion Criteria: * Aged less than or equal to 25 years at enrollment * Receiving treatment for AML or relapsed ALL at St. Jude and treatment is expected to cause prolonged (\> 7 days) severe neutropenia (ANC \< 500/ml) * Expected to receive care at St. Jude for at least 56 days following enrollment on the protocol * Female participant, greater than or equal to 9 years old, has a documented negative pregnancy test prior to receipt of study drug. Exclusion Criteria: * Allergy to vancomycin, dalbavancin, teicoplanin, levofloxacin or ciprofloxacin (Not including non-anaphylactic vancomycin infusion reaction) * Documented past or current infection or colonization with pathogenic bacteria resistant to vancomycin plus either ciprofloxacin or levofloxacin, within the prior 6 months * Diagnosed with long QT syndrome * Any condition judged by the investigator to put the participant at high risk from participation * Suspected or proven active bacterial infection * Inability to complete requirements of participation in the study (in the opinion of the investigator) * Expected survival \