Levofloxacin to prevent bacterial infection in patients with acute myeloid leukemia treated by venetoclax and azacitidine: a Toulouse-Bordeaux DATAML registry study

Abstract Objectives Antibiotic prophylaxis for patients with cancer remains a controversial issue and is not broadly recommended for hematological malignancies. The venetoclax (VEN) and azacitidine (AZA) combination allows for high rates of complete remission in acute myeloid leukemia (AML) but enhances the incidence of febrile neutropenia (FN) compared to AZA alone, making primary antibiotic prophylaxis a relevant question. Patients and Methods Patients with AML who received VEN-AZA were selected from the DATAML registry to investigate the use of levofloxacin (LEVO) prophylaxis, administered at 500 mg/day from day 10 following the first course of VEN-AZA, until neutrophil recovery (>0.5x109/L). Results A cohort of 258 patients was identified (median age 69.8 years, IQR 20.4-87.4), 72 of them having received LEVO and 186 treated with standard of care (SOC). VEN-AZA was used for newly diagnosed AML in 52.7% of cases. FN occurred in 33.3% of LEVO patients vs. 37.1% of SOC patients (p=0.572). Time from day 10 VEN-AZA to FN was significantly delayed in LEVO patients (12.5 days vs 8 in SOC; p=0.037). Pulmonary infections were considerably reduced by LEVO (10.2% vs 1.4%, p=0.018) as well as those involving enterobacterales (9.1% vs 1.4%; p=0.029). No early increase in fluoroquinolone resistance was detected (p=0.142). Conclusion Levofloxacin as primary prophylaxis in patients with AML treated with VEN-AZA seems to decrease the rate of documented infections even if the incidence of FN was not significantly decreased. This prophylaxis shaped a different clinical and microbiological landscape without significant increase of antibiotic resistance.