[Multicenter Prospective Study of Different Induction Regimens of Azacytidine in Treatment of Elderly Patients with Acute Myeloid Leukemia].

Objective: To observe the efficacy and safety of different induction regimens of same total dosage of azacitidine (Aza), including standard dose (standard dose group) and low-dose long-term (adjusted dose group), in the treatment of elderly acute myeloid leukemia (AML).

Methods: A total of 103 elderly patients with AML (non-acute promyelocytic leukemia) from January 2020 to June 2021 were enrolled. Aza was administered at the standard dose of 75 mg/(m·d) for 7 days in the standard dose group (50 cases), while at 100 mg/d for 7-12 days in the adjusted dose group (53 cases). The administration days in adjusted dose group was calculated based on the total standard dose of the patient's single course of treatment. The efficacy and safety between standard dose group and adjusted dose group were compared. Subgroup analysis were performed in the two groups for Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy for efficacy and safety.

Results: There were no significant differences in overall response rate (ORR), incidence of adverse reaction, and 1-year overall survival (OS) rate between standard dose group and adjusted dose group ( >0.05). The ORR of combination was higher than that of Aza alone ( < 0.05), while there was no significant difference in ORR between Aza combined with BCL-2 inhibitor and Aza combined with low-dose chemotherapy ( >0.05). The combination of BCL-2 inhibitor did not increase the incidence of adverse reactions compared wtih Aza alone. There was a higher risk of myelosuppression and pulmonary infection with a combination of low-dose chemotherapy than with a combination of BCL-2 inhibitor and Aza alone ( <0.05). No significant difference was observed in 1-year OS between Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy ( >0.05).

Conclusions: Both two induction regimens can be used in elderly AML patients who cannot tolerate intensive chemotherapy with similar overall effectiveness and safety. Aza combined with low-dose chemotherapy may result in increased ORR and an increased incidence of serious adverse reactions, and may not result in longer survival compared with Aza alone. Aza combined with BCL-2 inhibitor not only has similar effect in complete remission, objective response rate, and OS compared with Aza combined with low-dose chemotherapy, but also has higher safety.