Gene Therapy Versus Common Care for Eligible Individuals With Sickle Cell Disease in the United States: A Cost-Effectiveness Analysis.

The U.S. Food and Drug Administration recently approved 2 genetic therapies for sickle cell disease. Both therapies increase the production of nonsickling red blood cells, either fetal hemoglobin or a gene therapy–derived hemoglobin similar to hemoglobin A. In addition, both therapies require collection of a patient's stem cells, modification of the cells in the laboratory, high-dose chemotherapy to remove existing bone marrow cells, and a single-dose infusion of the patient's modified stem cells. This article uses 2 different cost-effectiveness models to estimate whether these therapies provide enough value to justify their high costs. Visual Abstract. Gene Therapy Versus Common Care for Eligible Individuals With Sickle Cell Disease in the United States: The U.S. Food and Drug Administration recently approved 2 genetic therapies for sickle cell disease. Both therapies increase the production of nonsickling red blood cells, either fetal hemoglobin or a gene therapy–derived hemoglobin similar to hemoglobin A. In addition, both therapies require collection of a patient's stem cells, modification of the cells in the laboratory, high-dose chemotherapy to remove existing bone marrow cells, and a single-dose infusion of the patient's modified stem cells. This article uses 2 different cost-effectiveness models to estimate whether these therapies provide enough value to justify their high costs. Background: Sickle cell disease (SCD) and its complications contribute to high rates of morbidity and early mortality and high cost in the United States and African heritage community. Objective: To evaluate the cost-effectiveness of gene therapy for SCD and its value-based prices (VBPs). Design: Comparative modeling analysis across 2 independently developed simulation models (University of Washington Model for Economic Analysis of Sickle Cell Cure [UW-MEASURE] and Fred Hutchinson Institute Sickle Cell Disease Outcomes Research and Economics Model [FH-HISCORE]) using the same databases. Data Sources: Centers for Medicare & Medicaid Services claims data, 2008 to 2016; published literature. Target Population: Persons eligible for gene therapy. Time Horizon: Lifetime. Perspective: U.S. health care sector and societal. Intervention: Gene therapy versus common care. Outcome Measures: Incremental cost-effectiveness ratios (ICERs), equity-informed VBPs, and price acceptability curves. Results of Base-Case Analysis: At an assumed $2 million price for gene therapy, UW-MEASURE and FH-HISCORE estimated ICERs of $193 000 per QALY and $427 000 per QALY, respectively, under the health care sector perspective. Corresponding estimates from the societal perspective were $126 000 per QALY and $281 000 per QALY. The difference in results between models stemmed primarily from considering a slightly different target population and incorporating the quality-of-life (QOL) effects of splenic sequestration, priapism, and acute chest syndrome in the UW model. From a societal perspective, acceptable (>90% confidence) VBPs ranged from $1 million to $2.5 million depending on the use of alternative effective metrics or equity-informed threshold values. Results of Sensitivity Analysis: Results were sensitive to the costs of myeloablative conditioning before gene therapy, effect on caregiver QOL, and effect of gene therapy on long-term survival. Limitation: The short-term effects of gene therapy on vaso-occlusive events were extrapolated from 1 study. Conclusion: Gene therapy for SCD below a $2 million price tag is likely to be cost-effective when applying a societal perspective at an equity-informed threshold for cost-effectiveness analysis. Primary Funding Source: National Heart, Lung, and Blood Institute. [ABSTRACT FROM AUTHOR]