Azacitidine Is Well-Tolerated and Is Associated with High Response Rate in Elderly Patients with Higher-Risk Myelodysplastic Syndromes: A Single Center Observational Study

Background/Objectives: Azacitidine (AZA) is the standard of care for patients with higher-risk Myelodysplastic Syndromes (MDS). There is limited real-life data, however, characterizing its efficacy and safety profile in elderly patients. Methods: We conducted a single-center retrospective cohort chart review to compare front-line AZA therapy in patients ≥75 years (elderly) vs. <75 years (younger) with higher-risk MDS treated at our cancer center. The primary endpoint was overall survival and main secondary endpoints included response, as per the 2006 International Working Group consensus criteria, leukemia-free survival, transfusion independence, and safety outcomes. Results: In total, 55 patients were elderly (median age: 79.9 years), including 27 patients >80 years, and 41 were younger (median age: 69.4 years). Baseline demographic variables were similar between both groups. The majority of elderly patients (98%) received the full dose of AZA (75 mg/m2), compared with 90% of younger patients. The median number of AZA cycles was 8 (range: 2–69) in elderly and 7.75 (range: 1–96) in younger patients. Treatment delays occurred in 36.4% of elderly and 29.3% of younger patients, most commonly due to infection complications in both groups (p = 0.076). Disease control rates (complete remission + partial remission + stable disease) were 92.9% in the younger subgroup and 96.4% in the elderly subgroup (p = 0.154). Relapse occurred in 48.8% of younger patients and 40.0% of elderly patients. Median overall survival (OS) was 17.3 months for the younger subgroup, 15.7 months for the elderly subgroup (p = 0.771), and 11.9 months among patients >80 years (p = 0.381). Mortality rates and causes of death were similar between both subgroups. Most common causes of death included disease progression, sepsis, febrile neutropenia, and pneumonia. Conclusions: AZA monotherapy resulted in a high response rate and was well-tolerated in elderly patients with higher-risk MDS. These findings remain consistent in the real-world setting despite potential confounding factors that may contribute to inferior outcomes.