DP022 | OUTPATIENT VS INPATIENT VENETOCLAX+AZACITIDINE REGIMEN IN ELDERLY AML: A RETROSPECTIVE ANALYSIS

Background: venetoclax (VEN) combined with hypomethylating agents is currently the standard of care for the treatment of elderly, unfit patients with acute myeloid leukemia (AML). The initiation of treatment in outpatients has been infrequently investigated, as it was initially conducted in inpatient settings due to the potential risks of infection and tumor lysis syndrome. Methods: in this retrospective study, 65 treatment naïve elderly patients diagnosed with AML and treated at our institution between 2017 and 2024 were analyzed. Of these, 35 patients received VEN+azacitidine (AZA) as first-line treatment (frontline group) while 30 patients received the same regimen after progression on prior AZA treatment (R/R group). Thirty-eight patients (58.5%) were treated as outpatients, while 27 patients (41.5%) were hospitalized. Results: the median age of the cohort was 73 years (range, 53-81). Twenty-two patients were ≥75 years and 37 patients were male. Regarding AML subtype, 67.7% of patients presented de novo AML, while 32.3% had secondary AML. Overall, 58.5% of patients received antimicrobial prophylaxis. Inpatients were slightly younger, with a median age of 72 years (range, 57-79) compared to 74 years (range, 53-81) of outpatients (p=.015). The median white blood cell (WBC) count was higher in patients receiving inpatient care, with a median of 7.3 x109/L (range, 0.1-274.0) compared to 2.9 x109/L (range, 0.8-52.0) in outpatients (p=0.020). There were no considerable differences concerning gender, hemoglobin and platelet counts, fitness, infection prophylaxis and cumulative incidence of infections. Treatment setting emerged as a key predictive factor for infection development during the first course of AZA+VEN in both univariate [HR=0.257, p=.016, (95%CI, 0.08-0.7)] and multivariate analysis [HR=.256, p=.035, (95%CI, 0.07-0.9)]. Inpatients had a significantly higher infection rate (81.4%) compared to outpatients (44.7%) (p < 0.0044). In R/R group, 1-year EFS was 68% for outpatients (95%CI, 51-91) vs. 38% for inpatients (95%CI,15-92, p=0.0098). One-year OS was 77% (95% CI, 62-100) in outpatients compared to 38% (95%CI, 15-92) in inpatients (p=.052). Conclusions: our study suggests that outpatient administration of the first cycle of AZA+VEN therapy should be preferred as a beneficial option, offering advantages such as ameliorated survival, decreased risk of hospital‐acquired infections, improved quality of life and reduced healthcare costs.