Infections during AML induction chemotherapy in a contemporary cohort without fluoroquinolone prophylaxis

Recent advances in the treatment of acute myeloid leukemia (AML) and optimized supportive care have improved survival outcomes. However, infections during remission induction chemotherapy remain a leading cause of morbidity and mortality. While antifungal prophylaxis is standard, the role of routine antibacterial prophylaxis is increasingly debated due to adverse effects and resistance. This study aimed to characterize infectious complications in a real-world AML cohort receiving induction chemotherapy without routine antibacterial prophylaxis.

We retrospectively analyzed 103 adults with newly diagnosed AML who underwent intensive induction therapy at LMU University Hospital between January 2019 and December 2022. All patients received antifungal prophylaxis whereas antibacterial fluoroquinolone (FQ) prophylaxis was not administered. We assessed febrile episodes, clinically and microbiologically documented infections, ICU/IMC admissions, and 30-/90-day mortality.

Febrile episodes occurred in almost all patients. Clinically documented infections accounted for 29.8% and microbiologically confirmed infections for 22.9% of febrile events. Bacteraemia was evenly distributed between Gram-positive and Gram-negative pathogens; multidrug resistance was rare. Proven or probable invasive fungal infections occurred in 6.8% of patients. In 47.2% of cases, the cause of fever remained unknown. Infection-related 30-day mortality was 4.9%. Factors associated with increased 30-day mortality included age ≥ 65 years, ECOG ≥ 2, secondary AML, and ICU/IMC admission for infection.

Infections remain a major challenge during AML induction therapy. Our findings suggest that FQ prophylaxis should be reevaluated in this setting, focussing on a more individualized approach. In addition, novel diagnostic tools are urgently needed to enable earlier and more targeted infection management in this high-risk population.