Cost-effectiveness of upfront vs delayed allogeneic hematopoietic stem cell transplant for intermediate risk AML

The ETAL-1 trial demonstrated that upfront allogeneic hematopoietic stem cell transplant (HSCT) improved disease-free survival, but not overall survival, when compared with consolidation chemotherapy followed by "delayed" HSCT on relapse in patients with intermediate-risk acute myeloid leukemia (AML). However, the health-economic implications of upfront HSCT compared with delayed HSCT are unknown. We developed a partitioned survival analysis model using derived survival data, probabilities of salvage treatments, utilities, and costs from the ETAL-1 trial and published literature. The primary outcome was the incremental net monetary benefit (INMB) from the perspective of the United States and United Kingdom health care systems, at all accepted willingness-to-pay (WTP) thresholds: $50 000 to $150 000 per quality-adjusted life year (QALY), and £20 000 to £30 000 per QALY, respectively. The respective INMBs favored upfront HSCT, and were $497 100 (95% confidence interval [CI], $259 800-$719 600) and £235 600 (95% CI, £166 800-£298 500) at WTP thresholds of $150 000 per QALY and £30 000 per QALY. Across deterministic sensitivity analyses, no model input changed the conclusion that upfront HSCT is the cost-effective strategy in either jurisdiction. Probabilistic sensitivity analysis showed that upfront HSCT was cost-effective in 100% of iterations, and was less costly and more effective (ie, "dominant") in >90% of iterations in both health care systems. In conclusion, we conducted a partitioned survival analysis based on the ETAL-1 trial, and showed that proceeding to HSCT in first remission is the cost-effective strategy in the care of patients with intermediate-risk AML in both the United States and the United Kingdom, as compared with delayed HSCT.