Oral Azacitidine for Maintenance Treatment of Acute Myeloid Leukaemia After Induction Therapy: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

The National Institute for Health and Care Excellence (NICE) invited the manufacturer (Celgene) of oral azacitidine (ONUREG), as part of the Single Technology Appraisal (STA) process, to submit evidence for the clinical effectiveness and cost-effectiveness of oral azacitidine for maintenance treatment of acute myeloid leukaemia (AML) after induction therapy compared with watch-and-wait plus best supportive care (BSC) and midostaurin. Kleijnen Systematic Reviews Ltd, in collaboration with Maastricht University Medical Centre+, was commissioned to act as the independent Evidence Review Group (ERG). This paper summarises the company submission (CS), presents the ERG's critical review on the clinical and cost-effectiveness evidence in the CS, highlights the key methodological considerations and describes the development of the NICE guidance by the Appraisal Committee. In the QUAZAR AML-001 trial, oral azacitidine significantly improved overall survival (OS) versus placebo: median OS gain of 9.9 months (24.7 months versus 14.8 months; hazard ratio (HR) 0.69 (95% CI 0.55-0.86), p < 0.001). The median time to relapse was also better for oral azacitidine, and the incidences of TEAEs were similar for the two arms. The company excluded two of the comparators listed in the scope, low-dose cytarabine and subcutaneous azacitidine, informed only by clinical expert opinion, leaving only best supportive care (BSC) and midostaurin for the FLT3-ITD and/or FLT3-TKD (FLT3 mutation)-positive subgroup. An ITC comparing oral azacitidine to midostaurin as maintenance therapy in the appropriate subgroup demonstrated that the OS and relapse-free survival (RFS) HRs were favourable for oral azacitidine when compared with midostaurin. However, in the only available trial of midostaurin as maintenance treatment in AML that was used for this ITC, subjects were not randomised at the maintenance phase, but at induction, which posed a substantial risk of bias. The revised and final probabilistic incremental cost-effectiveness ratio (ICER) presented by the company, including a commercial arrangement, was 32,480 pound per quality-adjusted life year (QALY) gained for oral azacitidine versus watch-and-wait plus BSC. Oral azacitidine was dominant versus midostaurin in the FLT-3 subgroup. The ERG's concerns included the approach of modelling haematopoietic stem cell transplantation (HSCT), the generalisability of the population and the number of cycles of consolidation therapy pre-treatment in the QUAZAR AML-001 trial to UK clinical practice, and uncertainty in the relapse utility. The revised and final ERG base case resulted in a similar probabilistic ICER of 33,830 pound per QALY gained versus watch-and-wait plus BSC, but with remaining uncertainty. Oral azacitidine remained dominant versus midostaurin in the FLT-3 subgroup. After the second NICE appraisal committee meeting, the NICE Appraisal Committee recommended oral azacitidine (according to the commercial arrangement), within its marketing authorisation, as an option for maintenance treatment for AML in adults who are in complete remission, or complete remission with incomplete blood count recovery, after induction therapy with or without consolidation treatment, and cannot have or do not want HSCT.