Abstract
Etranacogene dezaparvovec (EDZ), a novel one-time gene therapy for severe/moderately severe haemophilia B, provides sustained factor IX (FIX) activity, usually eliminating the need for lifelong replacement therapy. To evaluate cost-effectiveness of EDZ vs. prophylaxis with eftrenonacog alfa (rFIXFc) in adults with haemophilia B in Sweden. A lifetime Markov model (age 41.5 up to 100 years) was developed based on four health states defined by stratified Pettersson scores, a measure of joint deterioration. Phase 3 trial results over 60-months informed efficacy parameters along with publicly available Swedish healthcare costs. Main outcomes were costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). A non-linear Bayesian model predicted FIX activity levels, projected to 60 years. A 3% discount was applied for costs and health outcomes. Uncertainty was assessed through sensitivity analyses. Accumulated QALYs were 20.41 EDZ vs. 18.66 rFIXFc. The QALY gain of 1.75 for EDZ was attributed to differential bleed rates, a utility increment for patients receiving EDZ, and disutility of administering rFIXFc regular infusions. EDZ resulted in total lifetime cost savings of ∼21.3 million SEK, driven by savings in drug costs (∼21.0 million SEK). The impact on other cost items was minimal. Results showed dominance of EDZ vs. rFIXFc and were consistent across sensitivity analyses. A scenario analysis starting at age 18 years with 0% discount showed total lifetime savings of ∼89.3 million SEK. EDZ is an effective and cost-saving treatment vs. rFIXFc for adults with severe/moderately severe haemophilia B, reducing clinical and economic burden.