Cost-effectiveness of etranacogene dezaparvovec compared to eftrenonacog alfa for the treatment of adult patients with severe and moderately severe haemophilia B in Sweden.

INTRODUCTION: 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.

AIM: To evaluate cost-effectiveness of EDZ vs. prophylaxis with eftrenonacog alfa (rFIXFc) in adults with haemophilia B in Sweden.

METHODS: 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.

RESULTS: 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.

CONCLUSION: EDZ is an effective and cost-saving treatment vs. rFIXFc for adults with severe/moderately severe haemophilia B, reducing clinical and economic burden.