PND25 - A Cost-Effectiveness Analysis of Voretigene Neparvovec for Vision Loss Due to Biallelic Rpe65-Mediated Inherited Retinal Disease

Abstract

Inherited retinal diseases (IRDs) are rare, but are important causes of childhood blindness. A subset of IRDs are caused by mutations in the gene RPE65. Voretigene neparvovec (VN) was developed to treat RPE65-mediated IRDs; it is the first such gene therapy approved in the U.S. We evaluated the cost-effectiveness of VN compared to standard of care (SoC) from US health care system and societal perspectives. We developed a Markov model using annual cycles over a lifetime horizon. The modeled population was US patients with a mean age of 15 years, baseline best eye visual acuity (VA) of 1.02 logMAR and average visual field (VF) of 364 degrees. We tracked age, VA, VF, blindness, quality-of-life and costs. Parameters were obtained from publicly available databases, published literature, and expert opinion. Outcomes included discounted (3% per year) quality-adjusted life-years (QALYs), costs (2018 US$), and incremental cost per QALY (ICER). We conducted univariate and probabilistic sensitivity analyses (PSA), and a subgroup analysis of 3-year-olds with better baseline vision. Expected QALYs were 17.3 for VN, and 16.0 for SoC. Health system perspective costs were $1,039,019 (VN) and $213,399 (SoC) yielding an ICER of $643,813. Societal perspective costs were $2,515,320 (VN) and $1,889,605 (SoC), yielding an ICER of $480,130/QALY. The results in the 3-year old population yielded ICERs of $287,915/QALY (health system) and $135,331/QALY (societal). ICERs were sensitive to the utilities, cost of VN, and the baseline VA. Only the 3-year-old societal perspective had a >50% chance of being cost-effective at a $150,000/QALY threshold (69%). At the current cost, VN is likely to exceed a cost-effectiveness threshold of $150,000/QALY, or $250,000/QALY for ultra-rare conditions, except in younger populations from a societal perspective.