Venetoclax duration outcomes analysis in MDS/AML within a community hospital.

e18511 Background: Hypomethylating agents (HMA) and venetoclax (Ven) are routinely used in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Limited data exist on varied Ven duration and have not revealed significant outcome differences (Karrar et al). We investigated real-world Ven prescribing patterns and early outcomes. Methods: Adult AML and MDS patients (pts) who received frontline HMA-Ven from 1/2020-12/2023 were stratified by Ven duration (7, 14, 21, or 28 days). Response at first post-treatment biopsy, overall (OS) and 1 year survival (1yOS), CTCAE grade 3+ neutropenia/thrombocytopenia, time to count recovery, and incidence of tumor lysis syndrome (TLS) and bacteremia were evaluated. Kaplan-Meier method, Cox proportional hazards model, and descriptive statistics were used. Results: 53 pts (62% male) with median age 69 years (range 63-73) were evaluated. Most received decitabine (81%), had adverse ELN risk (83%), and were de novo AML (66%). Median follow up was 10.7 mo (range 3.3-43) but 21.6 mo for surviving pts (range 10.7-43). Allogeneic stem cell transplant took place in 19 pts. The Ven 21 cohort was excluded from further outcomes analysis due to N=1. 1yOS favored Ven 28 compared to Ven 7 (66.4% vs 33.3%, p =0.014) but there was no significant difference in CR/CRi ( p =0.13) or OS ( p =0.18) between Ven cohorts. MRD negativity was achieved in 48% (14/29) and was similar across cohorts. Univariate analysis of OS revealed no significant impact by Ven duration, ELN risk, or age. Nearly all experienced G3+ neutropenia and thrombocytopenia with similar time to count recovery. TLS (9.6%) and bacteremia (3.8%) incidences were low overall. Conclusions: In this community hospital cohort, Ven 7 patients had significantly worse 1yrOS vs Ven 28; there was no difference in OS. Our findings, consistent with other retrospective studies, imply shorter Ven durations may be as effective but with minimal difference in hematologic toxicities. A selection bias in prescribing patterns likely exists in this and other retrospective studies. More data is needed to confirm whether shorter durations of Ven may be equivalent. Group CR/CRi, N (%) / MRD-, N (%) mOS, mo (range) 1yOS (95% CI) ≥G3 neutropeniaN (%) ≥G3 thrombo-cytopenia, N (%) Time to ANC >1.0 (days), median (range) Time to PLT >50, (days), median (range) Overall (N=52) 29/52 (55.8) /14/29 (48) 10.7(9-22.5) 47.1% (35.2-63) 27/28 (96.4) 24/29 (82.8) N=45/5244 (7-184) N=44/5224 (6-170) 7 (N=18) 8/18 (44.4) /5/9 (55) 7.2(1.8-26.1) 33.3% (17.3-64.1) 7/8 (87.5) 8/9 (88.9) N 12/1852 (10-131) N 15/1819 (11-124) 14 (N=10) 5/10 (50) /3/8 (38) 10.1(3-22.5) 30% (11.6-77.3) 5/5 (100) 6/6 (100) N = 10/1045 (7-111) N = 10/1023.5 (17-55) 28 (N=24) 16/24 (66.7) /6/12 (50) 15.6 (3.3-43) 66.4% (50-88.4) 15/15 (100) 10/14 (71.4) N=23/2440 (7-184) N=19/2428 (6-170) P-values 7 vs 14 0.78 / 0.46 0.64 0.47 0.41 0.40 0.92 0.58 7 vs 28 0.15 / 0.80 0.13 0.014 0.16 0.98 0.18 0.17 14 vs 28 0.36 / 0.58 0.11 0.07 1.0 0.14 0.36 0.46