COST-EFFECTIVENESS OF ETRANACOGENE DEZAPARVOVEC VERSUS FACTOR IX PROPHYLAXIS FOR SEVERE OR MODERATELY SEVERE HAEMOPHILIA B IN THE UNITED KINGDOM
Author(s)
Howard Thom, PhD1, Priyanka Raheja, MD2, Dan Betts, MS3, Douglass Drelich, MD4, Radovan Tomic, MS5, Maciej Maruszczak, PhD6, Albert Kwarciak, MS6, Jessie Bertram, MS6, Songkai Yan, MS4.
1University of Bristol, Bristol, United Kingdom, 2The Royal London Hospital Haemophilia Centre, Bart Health NHS Trust, London, United Kingdom, 3CSL Behring, Haywards Heath, United Kingdom, 4CSL Behring, King of Prussia, PA, USA, 5CSL Behring, Milan, Italy, 6Kintiga, Cambridge, United Kingdom.
1University of Bristol, Bristol, United Kingdom, 2The Royal London Hospital Haemophilia Centre, Bart Health NHS Trust, London, United Kingdom, 3CSL Behring, Haywards Heath, United Kingdom, 4CSL Behring, King of Prussia, PA, USA, 5CSL Behring, Milan, Italy, 6Kintiga, Cambridge, United Kingdom.
OBJECTIVES: To assess the cost-effectiveness of etranacogene dezaparvovec versus prophylactic factor IX (FIX) replacement therapy for adults with severe or moderately severe haemophilia B (FIX ≤2%) in the United Kingdom (UK), and to explore outcome-based arrangements (OBAs) under conservative durability scenarios.
METHODS: A cohort-based Markov model with 4 health states (no bleed, non-joint bleed, joint bleed, death) and weekly cycles was developed. Clinical inputs were informed by 60-month data from the phase 3 HOPE-B study and indirect treatment comparisons vs FIX therapy. Long-term FIX durability of etranacogene dezaparvovec beyond available data was projected using a previously presented Bayesian model. Costs were estimated using National Health Service reference values and list prices. Utilities were derived from HOPE-B EQ-5D data and literature. Deterministic, probabilistic, sensitivity, and scenario analyses were performed.
RESULTS: In the deterministic base case, etranacogene dezaparvovec generated more quality-adjusted life years (QALYs) (21.86 vs 20.66) and lower lifetime costs (£3,621,332 vs £8,656,082) than prophylactic FIX, yielding a QALY gain of 1.21 and cost savings of £5,034,750 at list prices across a lifetime horizon. Probabilistic analysis showed a mean (credible interval) QALY gain of 1.31 (0.21, 3.05), cost savings of -£5,238,647 (-£8,260,560, -£2,301,180), and a 99.99% probability of cost-effectiveness at the threshold limit of £25,000/QALY. Findings were robust across sensitivity and scenario analyses, including alternative baseline age, bleed rates and utilities. A threshold analysis showed that etranacogene dezaparvovec remained cost-effective if efficacy held ≥10-years post-treatment. OBAs ensured cost-effectiveness of etranacogene dezaparvovec even under an extreme, deliberately pessimistic durability scenario which falls well below the durability suggested by observed HOPE-B 5-year data.
CONCLUSIONS: At list prices, etranacogene dezaparvovec was cost-effective and cost-saving versus prophylactic FIX replacement therapy for severe or moderately severe haemophilia B in the UK. Results were robust to extensive uncertainty analyses. OBA scenarios provided payer financial protection under highly conservative durability assumptions.
METHODS: A cohort-based Markov model with 4 health states (no bleed, non-joint bleed, joint bleed, death) and weekly cycles was developed. Clinical inputs were informed by 60-month data from the phase 3 HOPE-B study and indirect treatment comparisons vs FIX therapy. Long-term FIX durability of etranacogene dezaparvovec beyond available data was projected using a previously presented Bayesian model. Costs were estimated using National Health Service reference values and list prices. Utilities were derived from HOPE-B EQ-5D data and literature. Deterministic, probabilistic, sensitivity, and scenario analyses were performed.
RESULTS: In the deterministic base case, etranacogene dezaparvovec generated more quality-adjusted life years (QALYs) (21.86 vs 20.66) and lower lifetime costs (£3,621,332 vs £8,656,082) than prophylactic FIX, yielding a QALY gain of 1.21 and cost savings of £5,034,750 at list prices across a lifetime horizon. Probabilistic analysis showed a mean (credible interval) QALY gain of 1.31 (0.21, 3.05), cost savings of -£5,238,647 (-£8,260,560, -£2,301,180), and a 99.99% probability of cost-effectiveness at the threshold limit of £25,000/QALY. Findings were robust across sensitivity and scenario analyses, including alternative baseline age, bleed rates and utilities. A threshold analysis showed that etranacogene dezaparvovec remained cost-effective if efficacy held ≥10-years post-treatment. OBAs ensured cost-effectiveness of etranacogene dezaparvovec even under an extreme, deliberately pessimistic durability scenario which falls well below the durability suggested by observed HOPE-B 5-year data.
CONCLUSIONS: At list prices, etranacogene dezaparvovec was cost-effective and cost-saving versus prophylactic FIX replacement therapy for severe or moderately severe haemophilia B in the UK. Results were robust to extensive uncertainty analyses. OBA scenarios provided payer financial protection under highly conservative durability assumptions.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE569
Topic
Economic Evaluation
Disease
Genetic, Regenerative & Curative Therapies, Rare & Orphan Diseases, Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)