Background: Venetoclax (Ven), a highly selective BCL-2 inhibitor, combined with hypomethylating agents (HMAs) azacitidine (Aza) or decitabine (Dec) is approved for the treatment of newly diagnosed acute myeloid leukemia (ND AML) in patients (pts) who are ineligible to receive intensive chemotherapy. Previous clinical studies initiated Ven + HMA in an inpatient setting due to concerns of tumor lysis syndrome (TLS). This Phase 3b, single-arm, multicenter, open-label study (NCT03941964) evaluated the efficacy and safety of Ven + HMA in a US community-based outpatient setting. Methods: Pts with ND AML who were ineligible to receive intensive chemotherapy, had no evidence of spontaneous TLS at screening, and were deemed an appropriate candidate for outpatient initiation of Ven + HMA by the investigator were eligible. Pts received Ven (400 mg) in combination with Aza (75 mg/m²) or Dec (20 mg/m²) for up to 6 cycles during the study period. Pts could continue receiving commercially acquired Ven after the study period. All pts received TLS prophylaxis. The primary endpoint was the composite complete remission (CR) rate (CR + CR with incomplete hematologic recovery [CRi]) per modified International Working Group criteria. Secondary endpoints included CR or CRi rates and transfusion independence (TI). TLS was assessed per Howard criteria (Howard. N Engl J Med. 2011;364:1844). Results: At the 19 Oct 2021 cutoff date, 60 pts were enrolled and treated (Ven + Aza, n=30; Ven + Dec, n=30). Efficacy outcomes are shown in the Table. The composite CR rate was 58%. CR and CRi rates were 13% and 45%, respectively. Most pts (>50%) maintained TI, and 41% and 57% of pts dependent on red blood cells or platelets, respectively, converted to TI. Bone marrow blast clearance was achieved in 42 pts (70%) at a median 26 days after treatment initiation. The most common (≥50%) AEs were anemia (75%), neutrophil count decrease (55%), white blood cell count decrease (52%), and nausea (50%). Serious AEs occurred in 67% of pts, most commonly (≥15%) febrile neutropenia (28%) and sepsis (15%). Two pts (3%) had TLS; neither event led to treatment discontinuation. Of pts who achieved blast clearance, 12/42 (29%) had a new event of myelosuppression post-blast clearance and prior to the next cycle. Conclusions: The results of this US community-based study indicate that Ven + HMA is an effective treatment option for pts with ND AML and, with appropriate TLS prophylaxis and monitoring, can safely be initiated in an outpatient setting. Clinical trial information: NCT03941964.