Voretigene neparvovec 5 tera vector genomes/1ml concentrate and solvent for solution for injection vials

Background and aim: Advanced Therapy Medicinal Products (ATMPs) are innovative drugs based on genes, tissues, or cells that target rare and severe diseases. ATMPs have shown promising clinical outcomes but are associated with high costs, raising questions about cost-effectiveness. Hence, this systematic review aims to analyze the cost-effectiveness and cost-utility profiles of the European Medicines Agency-authorized ATMPs for treating rare diseases. Methods: A systematic review was conducted following PRISMA guidelines. Studies were identified by searching PubMed, Embase, Web of Science, and ProQuest scientific databases. Economic evaluations reporting incremental cost-effectiveness/utility ratios (ICERs/ICURs) for ATMPs were included. Costs were standardized to 2023 Euros, and a cost-effectiveness plane was constructed to evaluate the results against willingness-to-pay (WTP) thresholds of EUR 50,000, EUR 100,000, and EUR 150,000 per QALY, as part of a sensitivity analysis. Results: A total of 61 studies met the inclusion criteria. ATMPs for rare blood diseases, such as tisagenlecleucel and axicabtagene ciloleucel, were found to be cost-effective in a majority of studies, with incremental QALYs ranging from 1.5 to 10 per patient over lifetime horizon. Tisagenlecleucel demonstrated a positive cost-effectiveness profile in the treatment of acute lymphoblastic leukemia (58%), while axicabtagene ciloleucel showed a positive profile in the treatment of diffuse large B-cell lymphoma (85%). Onasemnogene abeparvovec for spinal muscular atrophy (SMA) showed uncertain cost-effectiveness results, and voretigene neparvovec for retinal diseases was not cost-effective in 40% of studies, with incremental QALYs around 1.3 and high costs exceeding the WTP threshold set. Conclusions: ATMPs in treating rare diseases show promising economic potential, but cost-effectiveness varies across indications. Policymakers must balance innovation with system sustainability, using refined models and the long-term impact on patient outcomes.

Abstract licence: CC BY

Abstract: Subretinal gene therapy trials began with the discovery of RPE65 variants and their association with Leber congenital amaurosis. The RPE65 protein is critical for the normal functioning of the visual phototransduction cascade. RPE65 gene knockout animal models were developed and showed similar diseased phenotypes to their human counterparts. Proof of concept studies were carried out in these animal models using subretinal RPE65 gene replacement therapy, resulting in improvements in various visual function markers including electroretinograms, pupillary light responses, and object avoidance behaviors. Positive results in animal models led to Phase 1 human studies using adeno-associated viral vectors. Results in these initial human studies also showed positive impact on visual function and acceptable safety. A landmark Phase 3 study was then conducted by Spark Therapeutics using a dose of 1.5 x10 11 vector genomes after dose-escalation studies confirmed its efficacy and safety. Multi-luminance mobility testing was used to measure the primary efficacy endpoint due to its excellent reliability in detecting the progression of inherited retinal diseases. After the study met its primary endpoint, the Food and Drug Administration approved voretigene neparvovec (Luxturna ® ) for use in RPE65 -associated inherited retinal diseases. Keywords: gene therapy, inherited retinal diseases, Leber congenital amaurosis, Luxturna, RPE65, voretigene neparvovec, retinitis pigmentosa, retina

Abstract licence: CC BY-NC 3.0

Biallelic mutations in the RPE65 gene affect nearly 8% of Leber Congenital Amaurosis and 2% of Retinitis Pigmentosa cases. Voretigene neparvovec (VN) is the first gene therapy approach approved for their treatment. To date, real life experience has demonstrated functional improvements following VN treatment, which are consistent with the clinical trials outcomes. However, there is currently no consensus on the characteristics for eligibility for VN treatment. We reviewed relevant literature to explore whether recommendations on patient eligibility can be extrapolated following VN marketing. We screened 166 papers through six research questions, following scoping reviews methodology, to investigate: (1) the clinical and genetic features considered in VN treatment eligibility; (2) the psychophysical tests and imaging modalities used in the pre-treatment and follow-up; (3) the potential correlations between visual function and retinal structure that can be used to define treatment impact on disease progression; (4) retinal degeneration; (5) the most advanced testing modalities; and (6) the impact of surgical procedure on treatment outcomes. Current gaps concerning patients' eligibility in clinical settings, such as pre-treatment characteristics and outcomes are not consistently reported across the studies. No upper limit of retinal degeneration can be defined as the univocal factor in patient eligibility, although evidence suggested that the potential for function rescue is related to the preservation of photoreceptors before treatment. In general, paediatric patients retain more viable cells, present a less severe disease stage and show the highest potential for improvements, making them the most suitable candidates for treatment.

Abstract licence: CC BY 4.0