Venetoclax plus decitabine as a bridge to allogeneic haematopoietic stem-cell transplantation in older patients with acute myeloid leukaemia (VEN-DEC GITMO): final report of a multicentre, single-arm, phase 2 trial

Background: Access to allogeneic haematopoietic stem-cell transplantation (HSCT) remains challenging for older patients (aged >60 years) with acute myeloid leukaemia. We aimed to evaluate the efficacy of venetoclax plus decitabine as first-line therapy and bridge to transplantation in this patient population. Methods: This multicentre, single-arm, phase 2 trial was conducted in 20 Gruppo Italiano Trapianto Midollo Osseo (GITMO) centres in Italy. Patients aged ≥60 and <75 years, with newly diagnosed acute myeloid leukaemia categorised as intermediate or high risk according to 2016 WHO and 2017 European LeukemiaNet, an ECOG performance status of less than 2, and considered fit for allogeneic HSCT were included. Patients received oral venetoclax with a 3-day ramp-up: 100 mg on day 1, 200 mg on day 2, and 400 mg once per day from day 3 of cycle one, and then every 28 days of each cycle (two to four in total). Decitabine was administered intravenously at a dose of 20 mg/m2 from days 1 to 5 every 28 days. At cycle one, patients were admitted to hospital for a minimum of 24 h, whereas subsequent cycles could be administered on an outpatient basis. Two additional cycles were allowed while waiting for allogeneic HSCT or for those with no response or partial response after cycle two. The primary endpoint was the proportion of patients who had allogeneic HSCT performed during first complete remission, assessed in all patients who received at least one dose of the study medication. This study was registered with ClinicalTrials.gov (NCT04476199, ongoing) and EudraCT (2020-002297-26). Findings: Between June 1, 2021, and Dec 30, 2022, 93 patients were enrolled and started venetoclax plus decitabine induction (44 [47%] at intermediate risk and 49 [53%] at high risk). The median age was 68·5 (IQR 60·3-74·7). All 93 participants were White, of whom 43 (46%) were female and 50 (54%) were male. The median follow-up was 236 days (IQR 121-506). 64 (69%) of 93 patients reached complete remission and 53 (57%) underwent allogeneic HSCT in complete remission. 53 (83%) of 64 with a complete remission underwent allogeneic HSCT. Five (8%) of 64 patients in complete remission relapsed before transplantation and four died as a consequence. Adverse events (grade ≥3) occurred in 49 (53%) of 93 patients. The most common adverse events were infections (including pneumonia, bacterial sepsis, and SARS-CoV-2 causing seven deaths among 28 [57%] of 49 patients), neutropenia (17 [35%]), thrombocytopenia (two [4%], including one fatal CNS bleeding), and cardiac events (four [8%], including one fatal heart failure). No treatment-related deaths were observed. Interpretation: Venetoclax plus decitabine induction can significantly enhance the feasibility of allogeneic HSCT in older patients with acute myeloid leukaemia who are deemed fit for transplantation. Funding: AbbVie and Johnson & Johnson.