This white paper examines the growing threat of antimicrobial resistance (AMR) in hematology-oncology and its implications for patients, clinical development and healthcare systems. Drawing on published literature, analysis of 27 phase III hematology-oncology clinical trials, and patient and clinician perspectives, it explores how infection risk can affect treatment delivery and outcomes, highlights gaps in current clinical trial reporting, and identifies actions to strengthen infection surveillance, prevention and AMR preparedness.