Hypomethylating agents combined with low-dose chemotherapy for elderly patients with acute myeloid leukaemia unfit for intensive chemotherapy: a real-world clinical experience

This study aimed to assess the efficacy and safety of hypomethylating agent (HMA)-based regimens in the treatment of older adult patients with acute myeloid leukaemia (AML), unfit for standard induction chemotherapy. Treatment outcomes and prognostic factors of 140 older adult patients with AML who were unfit for intensive chemotherapy and were treated with HMA-based therapies were retrospectively analysed. The median age of the group was 70 years, and poor-risk cytogenetics and secondary/treatment-related AML (s/t-AML) accounted for 45.6% and 34.3% of these patients, respectively. The overall response rate was 48.6%, and 40.1% for patients who achieved complete remission (CR) or CR with incomplete blood count recovery. The median overall survival (OS) was 10.4 months, and the 1-, 2-, and 5-year OS rates were 42.6%, 19.9%, and 4.9%, respectively. Early mortality accounted for 4.3% of all cases, and infection occurred in 87.1% of all patients during induction therapy. Patients who received HMA and low-dose chemotherapy presented with significantly superior response and long-term survival rates compared to those who received HMA alone. They also showed comparable outcomes to those treated with the azacitidine plus venetoclax protocol. Low-dose chemotherapy in combination with decitabine or azacitidine showed a similar response rate and prognosis. Age ≥ 75years and a white blood cell (WBC) count ≥ 10 × 109 cells/L were identified as independent adverse prognostic factors for OS, while poor-risk cytogenetics, percentage of bone marrow blasts, and s/tAML had no significant impact on OS when patients were treated with HMA-based regimens. In conclusion, HMA combined with low-dose chemotherapy was effective and safe in older adults with AML who were unfit for intensive chemotherapy, and no difference was observed between decitabine and azacitidine.