Alternative 5‐Azacitidine 5‐Day 100 mg/m ² Dosage Shows Non‐Inferiority to Classical Schedule for Myelodysplastic Neoplasm (MDS) and Chronic Myelomonocytic Leukaemia (CMML) Treatment

Introduction 5‐Azacitidine (AZA) is a major treatment option for myelodysplastic neoplasms (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). Here we evaluate the efficacy and toxicity of an alternative AZA regimen (100 mg/m 2 /day for 5 days/28 days) in 68 patients (51 MDS, 17 MDS/MPN) treated between 2008 and 2018. Results Median patient age was 66 years, with most patients (98%) having intermediate or high‐risk disease. Overall response rate (ORR) was 62% with 22% complete responses (CR). Median OS and median PFS were 22.5 and 18.2 months, respectively. Inferior response rates were calculated in therapy‐related MDS (t‐MDS) and MDS with excess blast II, with t‐MDS having also statistically worse OS and PFS. MDS/MPN patients showed 73.6% ORR with 31.5% CR. Transfusion independence (TI) for red blood cells (RBC) was achieved in 45.9% of transfusion‐dependent patients and in 30% for platelets. CR patients showed longer mOS and mPFS (70.6 and 64.7 months, respectively). Longer mOS was also correlated with allogeneic transplantation (48.8 vs. 16.9 months, p = 0.01) and RBC TI (25.4 vs. 13.3 months, p = 0.01). Grade 3/4 cytopenias occurred in 41.1% (neutropenia in 33.8%), and treatment‐related mortality was 7.4%. Conclusion This study demonstrates that this alternative AZA regimen has comparable efficacy and safety to the standard regimen, compared with historical data. Trial Registration The authors have confirmed clinical trial registration is not needed for this submission.