The combination of venetoclax with hypomethylating agents (VEM-HM) is considered standard of care for unfit or elderly patients with acute myeloid leukemia (AML). However, in the real world, venetoclax-based regimens have been used also to treat fit patients with AML, relapsed/refractory AML, and myelodysplastic syndromes (MDS).

To describe the early results of a multicentric study that evaluated patients with AML or MDS treated with venetoclax-based regimens in Brazil.

In this retrospective study, we evaluated clinical characteristics, complications and outcome of the first cycle of venetoclax-based regimens in the treatment of patients with AML and MDS.

A total of 64 patients were analyzed, 58% were male and the median age was 64 years (range 19-82). Most patients had AML (88%) with high risk disease (64%), and the main indication for venetoclax use was unfit patient (51%). VEN-HM was the most common regimen used (74%), while intensive chemotherapy regimens plus venetoclax was given in 10 patients. The most common symptoms were nausea (45%) and diarrhea (39%). Mucositis occurred in all patients receiving intensive chemotherapy vs. 20% in patients receiving VEN-HM (p < 0.001). Antifungal prophylaxis was used in 67.5% of patients, and micafungin was the most frequent agent (70%). Antibacterial and antiviral prophylaxis was used in 53% each. Febrile neutropenia occurred in 82% of patients, with 47% classified as fever of unknown origin, 15% bacteremia, 22% clinically docummented and 15% microbiologically documented infection. Proven or probable invasive fungal disease (IFD) was diagnosed in 1 of 10 (10%) patients receiving intensive chemotherapy and 3 of 43 (7.0%) receiving VEN-HM: aspergillosis in 1, fusariosis in 2 and invasive candidiasis in 1. At the end of the first cycle, 52% of patients had complete response (CR) or complete response with incomplete hematologic recovery (CRi) and 34% were considered refractory. CR + CRi was 57.5% in patients receiving VEN-HM and 30% in patients receiving intensive regimens. Death occurred in 6% of patients.

This is the first real-world study in Brazil evaluating the use o venetoclax-based regimens in patients with AML or MDS. These preliminary results show that a) antibacterial, antifungal and antiviral prophylaxis are a common practice; b) most clinicians chose an echinocandin, probabily to avoid venetoclax dose reduction; c) The 52% CR + CRi rate after the first cycle is similar to the rates observed in the randomized trial.