OBJECTIVES: To assess the long-term value of valoctocogene roxaparvovec-rvox (hemophilia A) and etranacogene dezaparvovec (hemophilia B) use, respectively, and to evaluate the relevance, and validity of the underlying data and assumptions used in published cost-effectiveness models.

METHODS: A systematic review of cost-effectiveness (utility) studies of novel hemophilia A and B gene therapy was conducted. Published studies were searched using PubMed and Embase from inception to September 15, 2023. We considered original research articles (without time restrictions) in the English language that conducted a cost-effectiveness/cost-utility analysis on the pharmaceutical treatments for hemophilia A and B, with a comparison of incremental costs and health effects using quality-adjusted life-years (QALYs), life-years, or equal-value gained life-years as health outcome metrics. Titles and abstracts were screened by three reviewers (two independent reviewers per abstract), and the conflicts were resolved by a third reviewer per abstract. Potentially eligible articles were read by all authors in full text to ensure they followed the inclusion criteria.

RESULTS: Two hundred thirty-eight studies were identified, of which four met the inclusion criteria. Three studies were conducted in the United States and one in the Netherlands. Gene therapy was shown to have high initial costs, however, all included studies (three hemophilia A and one hemophilia B) showed that gene therapies had lower overall costs and better health outcomes (dominant) than factor replacement therapies and emicizumab. The results were driven by the assumption that gene therapies will have a durable effect of at least 10 years, offset the high cost of current standard of care and improve quality of life.

CONCLUSIONS: Even with the high upfront cost and durability uncertainties of hemophilia A and B novel gene therapy, these products can be a cost-effective use of treatment resources if the treatment effects are durable over time.