Background: Anthracycline and cytarabine ("3+7") have been the standard induction therapy for acute myeloid leukemia (AML) for almost 4 decades. Only 60%-70% patients can achieve complete remission (CR) with "3+7" induction treatment in de nove AML. The novel induction regimens with higher CR rate are urgent needed. Venetoclax, a b-cell lymphoma 2 (BCL-2) inhibitor combining with hypomethylation agents (HMA) or low dose cytarabine has showed a high response rate and safe in elder AML patients [Dinardo CD, N Engl J Med. 2020; Dinardo CD, Lancet Oncol 2018; Wei AH, J Clin Oncol 2019]. Recently, venetoclax combined with FLAG-IDA induction achieved 90% CR rate in newly diagnosed adult AML (Dinardo CD, J Clin Oncol. 2021). Whether venetoclax combined with standard 3+7 regimen (daunorubicin + cytarabine) as induction therapy can further improve the CR rate in adult AML patients need to be investigated in a well-designed trial.

Objective: To evaluate the efficacy and safety of "3+7" (daunorubicin and cytarabine) combined with venetoclax induction regimen (DAV regimen) in young adult patients with de novo AML.

Design, setting and participants: Single-arm, prospective clinical trial conducted in the First Affiliated Hospital, Zhejiang University College of Medicine, China. Eligible patients (18-60 years old) with de novo AML (exclude acute promyelocytic leukemia) were enrolled since December 25, 2020, with final follow-up in July 31,2021.

Interventions: Patients were treated with daunorubicin 60mg/m 2 on days 1-3 (d1-3) and cytarabine 100 mg/m 2/d by continuous intravenous infusion daily on d1-7, combined with venetoclax (100mg d4, 200mg d5, 400mg d6-11).

Main outcomes and measures: The primary endpoint was the percentage of patients who achieved CR/CR with incomplete count recovery (CRi) after once cycle of DAV regimen. Secondary endpoints included minimal residual disease (MRD), overall survival (OS), event-free survival (EFS) and adverse events.

Results: Thirty-two patients were enrolled. Median age was 40 years old (range, 19-59), with poor-risk in 25% (8/32) of patients (European LeukemiaNet 2017 risk). Other characteristics of patients were listed in Table 1. The CR rate were 90.6% (29/32) (Table 1). Seven out eight (87.5%) patients with poor-risk achieved CR. Measurable residual disease-negative composite CR was attained in 65.5% (19 out 29) of total patients achieved CR, and 71.4% (5 out 7) of poor-risk patients achieved CR (Table 1). Common adverse events (>30%) included fatigue, nausea, bleeding, febrile neutropenia, infection, neutropenia, anemia and thrombocytopenia. The main grade ≥ 3 hematologic toxicities during induction were neutropenia (100%), anemia (100%) and thrombocytopenia (100%). The main grade ≥ 3 nonhematologic toxicities during induction were infection (81.3%), bleeding (28.1%) and mucositis (3.1%) (Table 1). No tumor lysis syndrome was observed. After a median follow-up of 118.5 days, no patient relapsed or died, and 24.1% (7/29) received allogeneic hematopoietic stem-cell transplantation in CR1.

Conclusions: The novel combination of "3+7" (daunorubicin and cytarabine) with venetoclax (DAV regimen) was effective and well tolerated in young adult patients with de novo AML, with high CR rate and deep remission.

Trial registration: The trial was registered in the Chinese Clinical Trial Register, number ChiCTR2000041509.

Disclosures

No relevant conflicts of interest to declare.

Author notes

 This icon denotes a clinically relevant abstract

Sign in via your Institution