Indirect treatment comparison of oral versus injectable azacitidine as maintenance therapy for acute myeloid leukemia

Aim: Evaluate the relative efficacy of oral versus injectable azacitidine (AZA) maintenance therapy in acute myeloid leukemia (AML) after complete remission. Materials & methods: Systematic literature review identified QUAZAR AML-001, HOVON 97 AML, UK NCRI AML16 and QoLESS-AZA-AMLE (sensitivity analysis) trials. Network meta-analysis and matching-adjusted indirect comparisons assessed survival outcomes. Results: In the network meta-analysis, combining the HOVON 97 and UK NCRI trials, oral AZA (QUAZAR) was associated with significantly improved overall survival (OS) versus injectable AZA (hazard ratio: 0.744; 95% credible interval: 0.557-0.998). After matching-adjusted indirect comparisons, to address differences in patient characteristics across trials, OS improvements were maintained with oral versus injectable AZA (hazard ratio: 0.753; credible interval: 0.563-0.998). Conclusion: In AML, maintenance therapy with oral AZA was associated with improved OS versus injectable AZA. Plain language summary: Older people with acute myeloid leukemia (AML) may have remission with or without blood count recovery, after first-line chemotherapy; however, remission is short lived and overall survival is limited (7-12 months). Ongoing treatment (maintenance therapy) after response to initial chemotherapy may prolong remission. Maintenance therapy with azacitidine (AZA) given by injection beneath the skin (subcutaneous) or into a vein (intravenous) can extend disease-free survival compared with no further treatment and best supportive care. However, treatment with intravenous AZA may only extend overall survival in certain patients. ONUREG (R) is a novel formulation of AZA that can be taken by mouth (orally), remains in the body for longer periods and has the potential for significant clinical benefits compared with intravenous AZA. Presently, there are no studies directly comparing outcomes of maintenance therapy with oral and injectable AZA in older people with AML. In this analysis, we used an indirect treatment comparison method including four clinical trials to explore the survival benefit associated with ONUREG and injectable AZA when used as maintenance therapies after response to initial chemotherapy in older people with AML. Findings showed ONUREG significantly improved overall survival compared with injectable AZA, with an almost 26% reduction in the risk of death. These results suggest that maintenance therapy with ONUREG significantly improves overall survival compared with injectable AZA in older people with AML who may have remission with or without blood count recovery, after first-line chemotherapy.

Automated summary

This study compared the efficacy of oral and injectable azacitidine in the maintenance therapy of acute myeloid leukemia. The results showed that oral azacitidine was associated with significantly improved overall survival. This has important clinical implications for the maintenance therapy of older patients with AML.