First Results from a Nationwide Prospective Non-Interventional Study of Venetoclax-Based 1st Line Therapies in Patients with Acute Myeloid Leukemia (AML) – Revive Study

Background:

The outcome of elderly patients with Acute Myeloid Leukemia (AML) is poor and treatment options in these high-risk groups are limited. Recently, venetoclax combinations with hypomethylating agents or low dose cytarabine were approved to treat patients with AML ineligible for intensive chemotherapy. However limited prospective data is available on the safety and efficacy of venetoclax treatment in routine clinical practice. Israel is among the first countries to have approved venetoclax-based combinations as first line therapy for AML and this treatment is fully reimbursed via the national health system. Here we present the initial results of a prospective, multicenter, nationwide trial that sought to assess the use of venetoclax-based therapy in a real-world setting.

Methods:

A prospective observational nationwide multicenter trial. Newly diagnosed patients with AML were enrolled at the time of venetoclax-based therapy initiation. Demographic, clinical and patient-related baseline characteristics were documented. Treatment patterns, safety and efficacy outcomes are reported. Patient related outcomes were assessed at baseline and after cycle 3 using the EQ-5D-5L and EORTC QLQ-C30 questionnaires.

Results:

A total of 70 patients were enrolled between August 2019 and June 2020 (data cut off) with a median age of 75 years (range 45-88) and a median follow-up of 74 days (8-232). Two-thirds of patients were males (62.9%). Over one-quarter (28.6%) of patients had an ECOG performance status of 2 or higher; the median modified Charlson Comorbidity Index (CCI) was 0 (range 1-4) with 27.1% with a CCI ≥2. De-novo AML was documented in 44.3%, secondary AML was diagnosed in 52.8% (secondary to MDS (27.1%), MPNs (11.4%) and therapy related AML (14.3%)). European LeukemiaNet (ELN) risk category was favorable, intermediate and adverse in 8.6%, 30% and 42.9%, respectively (Table 1). Time from diagnosis to initiation of therapy was 8 days (median, range 1-38). The main reasons for choosing venetoclax-based low intensity therapy as reported by treating physicians were patient related factors (mainly age>75 years, performance status) in the majority of cases and adverse disease biology predicting poor response to intensive chemotherapy in 17.1%. Of the 57 patients with available data, 38 (67%) initiated therapy in an inpatient setting with a median hospitalization duration of 12 days (range 1-62 days) and 19 (33%) patients started therapy as outpatients.

By data cutoff, of 63 patients that initiated therapy 45, 23 and 7 patients completed cycle 1, cycle 3 and cycle 6 assessments, respectively. Complete remission (CR) or CR with incomplete count recovery (CRi) was achieved in 23/44 (52.3%) patients that were assessed for best response. Of responding patients, 6 (23%, 5 CRi and 1 Partial Remission (PR)) went on to receive an allogeneic transplantation (median age 70.5 years).

Ninety percent of patients received venetoclax in combination with hypomethylating agents (azacytidine n=56, decitabine n=1). The full dose of 400mg was administered in 87% of cases with a median ramp-up duration of 3 days. Dose interruptions, dose modifications and dose discontinuations during follow-up were frequent and occurred in 41%, 35% and 27%, respectively.

During therapy 63.5% of patients experienced adverse events (AE) of any grade; severe AE's were recorded in 41.3% of patients. Febrile neutropenia was documented in 22.2% and Tumor Lysis Syndrome (TLS) was documented in 2 patients (grade 2; 3.2%). Early death rates at 30 and 60 days were 6.3% and 11.1%, respectively.

Conclusion:

In the real-world setting venetoclax-based therapies are effective and associated with manageable toxicity including in the outpatient setting. In routine practice patient-related factors and disease-related factors (disease-risk) both seem to play a role in choice of therapy.

Venetoclax treatment in real-life practice in Israel appears to follow general recommendations, is tolerable with approximately 90% of patients achieving target dose.

These observational data are expected to provide information on patient selection patterns, efficacy and safety and patient related outcomes in patients not in clinical trial.