A systematic review on the appropriate discounting rates for the economic evaluation of gene therapies: whether a specific approach is justified to tackle the challenges?

OBJECTIVES: Discounting the cost and effect for health intervention is a controversial topic over the last two decades. In particular, the cost-effectiveness of gene therapies is especially sensitive to the discount rate because of the substantial delay between the upfront cost incurred and long-lasing clinical benefits received. This study aims to investigate the influence of employing alternative discount rates on the incremental cost-effectiveness ratio (ICER) of gene therapies. METHODS: A systematic review was conducted to include health economic evaluations of gene therapies that were published until April 2023. RESULTS: Sensitivity or scenario analysis indicated that discount rate represented one of the most influential factors for the ICERs of gene therapies. Discount rate for cost and benefit was positively correlated with the cost-effectiveness of gene therapies, that is, a lower discount rate significantly improves the ICERs. The alternative discount rate employed in some cases could be powerful to alter the conclusion on whether gene therapies are cost-effective and acceptable for reimbursement. CONCLUSIONS: Although discount rate will have substantial influence on the ICERs of gene therapies, there lacks solid evidence to justify a different discounting rule for gene therapies. However, it is proposed that the discount rate in the reference case should be updated to reflect the real-time preference, which in turn will affect the ICERs and reimbursement of gene therapies more profoundly than conventional therapies.

Cost-Effectiveness of Lovotibeglogene Autotemcel (Lovo-Cel) Gene Therapy for Patients with Sickle Cell Disease and Recurrent Vaso-Occlusive Events in the United States.

BACKGROUND AND OBJECTIVE: Gene therapies for sickle cell disease (SCD) may offer meaningful benefits for patients and society. This study evaluated the cost-effectiveness of lovotibeglogene autotemcel (lovo-cel), a one-time gene therapy administered via autologous hematopoietic stem cell transplantation, compared with common care for patients in the United States (US) with SCD aged ≥ 12 years with ≥ 4 vaso-occlusive events (VOEs) in the past 24 months. METHODS: We developed a patient-level simulation model accounting for lovo-cel and SCD-related events, complications, and mortality over a lifetime time horizon. The pivotal phase 1/2 HGB-206 clinical trial (NCT02140554) served as the basis for lovo-cel efficacy and safety. Cost, quality-of-life, and other clinical data were sourced from HGB-206 data and the literature. Analyses were conducted from US societal and third-party payer perspectives. Uncertainty was assessed through probabilistic sensitivity analysis and extensive scenario analyses. RESULTS: Patients treated with lovo-cel were predicted to survive 23.84 years longer on average (standard deviation [SD], 12.80) versus common care (life expectancy, 62.24 versus 38.40 years), with associated discounted patient quality-adjusted life-year (QALY) gains of 10.20 (SD, 4.10) and direct costs avoided of $1,329,201 (SD, $1,346,446) per patient. Predicted societal benefits included discounted caregiver QALY losses avoided of 1.19 (SD, 1.38) and indirect costs avoided of $540,416 (SD, $262,353) per patient. Including lovo-cel costs ($3,282,009 [SD, $29,690] per patient) resulted in incremental cost-effectiveness ratios of $191,519 and $124,051 per QALY gained from third-party payer and societal perspectives, respectively. In scenario analyses, the predicted cost-effectiveness of lovo-cel also was sensitive to baseline age and VOE frequency and to the proportion of patients achieving and maintaining complete resolution of VOEs. CONCLUSIONS: Our analysis of lovo-cel gene therapy compared with common care for patients in the US with SCD with recurrent VOEs estimated meaningful improvements in survival, quality of life, and other clinical outcomes accompanied by increased overall costs for the health care system and for broader society. The predicted economic value of lovo-cel gene therapy was influenced by uncertainty in long-term clinical effects and by positive spillover effects on patient productivity and caregiver burden.

Remuneration of donors for cell and gene therapies: an update on the principles and perspective of the World Marrow Donor Association.

The cell and gene therapy (CGT) sector has witnessed significant advancement over the past decade, the inception of advanced therapy medicinal products (ATMPs) being one of the most transformational. ATMPs treat serious medical conditions, in some cases providing curative therapy for seriously ill patients. There is interest in pivoting the ATMP development from autologous based treatments to allogenic, to offer faster and greater patient access that should ultimately reduce treatment costs. Consequently, starting material from allogenic donors is required, igniting ethical issues associated with financial gains and donor remuneration within CGT. The World Marrow Donor Association (WMDA) established the Cellular Therapy Committee to identify the role WMDA can play in safeguarding donors and patients in the CGT field. Here we review key ethical principles in relation to donating cellular material for the CGT field. We present the updated statement from WMDA on donor remuneration, which supports non-remuneration as the best way to ensure the safety and well-being of donors and patients alike. This is in line with the fundamental objective of the WMDA to maintain the health and safety of volunteer donors while ensuring high-quality stem cell products are available for all patients. We acknowledge that the CGT field is evolving at a rapid pace and there will be a need to review this position as new practices and applications come to pass.

The estimated annual financial impact of gene therapy in the United States.

Gene therapy is a new class of medical treatment that alters part of a patient's genome through the replacement, deletion, or insertion of genetic material. While still in its infancy, gene therapy has demonstrated immense potential to treat and even cure previously intractable diseases. Nevertheless, existing gene therapy prices are high, raising concerns about its affordability for U.S. payers and its availability to patients. We assess the potential financial impact of novel gene therapies by developing and implementing an original simulation model which entails the following steps: identifying the 109 late-stage gene therapy clinical trials underway before January 2020, estimating the prevalence and incidence of their corresponding diseases, applying a model of the increase in quality-adjusted life years for each therapy, and simulating the launch prices and expected spending of all available gene therapies annually. The results of our simulation suggest that annual spending on gene therapies will be approximately $20.4 billion, under conservative assumptions. We decompose the estimated spending by treated age group as a proxy for insurance type, finding that approximately one-half of annual spending will on the use of gene therapies to treat non-Medicare-insured adults and children. We conduct multiple sensitivity analyses regarding our assumptions and model parameters. We conclude by considering the tradeoffs of different payment methods and policies that intend to ensure patient access to the expected benefits of gene therapy.

Coverage of genetic therapies for spinal muscular atrophy across fee-for-service Medicaid programs.

BACKGROUND: Genetic therapies are a promising treatment for children born with spinal muscular atrophy (SMA); however, their high price tags can evoke coverage restrictions. OBJECTIVE: To assess variation in coverage guidelines across fee-for-service state Medicaid programs for 2 novel genetic therapies, nusinersen and onasemnogene abeparvovec, that treat SMA. We also assessed the association of these coverage guidelines with use of the 2 genetic therapies. METHODS: We evaluated fee-for-service Medicaid coverage policies for nusinersen and onasemnogene abeparvovec from publicly available websites for the period February 2020-March 2020. We then documented areas of agreement and disagreement across 4 key coverage domains. We used 2018 and 2019 state Medicaid drug utilization data to calculate the use of nusinersen across Medicaid programs and assessed that use against the restrictiveness of the coverage guidelines. RESULTS: We identified 19 state Medicaid coverage guidelines for nusinersen. Most states agreed on diagnostics requirements; however, there were disagreements based on ventilator status. We identified 17 state Medicaid coverage guidelines for onasemnogene abeparvovec. There was more discordance in these coverage guidelines compared with nusinersen, notably in domains of SMN2 gene count and ventilator status. When comparing utilization of nusinersen with coverage restrictions, we found that the more restrictive states had considerably lower utilization of nusinersen. CONCLUSIONS: There was significant variation across fee-for-service Medicaid coverage policies for nusinersen and onasemnogene abeparvovec. Although states can impose individual coverage guidelines for each drug, we presented policy options that could reduce variation and potentially decrease the cost burden of these drugs. DISCLOSURES: This study was funded by Arnold Ventures. The authors have no conflicts of interest to disclose.

Hemophilia Gene Therapy Value Assessment: Methodological Challenges and Recommendations.

Gene therapy for hemophilia is designed to produce health gains for patients over many years. Rewarding that value creation on the basis of a one-time treatment implies a large upfront cost. This cost can only be justified by long-term health benefits and being cost-effective compared with conventional treatments. Yet, uncertainties about the long-term benefits make it challenging to assess clinical and economic value of gene therapies at launch. We identify and discuss key methodological challenges in assessing the value of gene therapy for hemophilia, including the immaturity of evidence on the durability of benefits, lack of definition and valuation of cure for chronic diseases, absence of randomized controlled trials, limitations of traditional quality of life measures in hemophilia, approach for qualifying cost-savings compared with current treatments, and choice of perspective. The Institute for Clinical and Economic Review has developed a framework for assessing single or short-term therapies (ICER-SST) and has applied it in hemophilia. After reviewing this framework and its application, we recommend the following when assessing the value of hemophilia gene therapies: (1) leveraging expert clinical opinion to justify assumptions on the durability of benefits; (2) using external synthetic controls and lead-in, self-controlled trials to assess comparative effectiveness; (3) addressing limitations of traditional quality of life measures through the use of modified utility collection approaches; (4) adjusting cost offsets from gene therapies with caution; (5) considering outcome-based contracting to address uncertainties about prices and long-term outcomes; and (6) presenting societal and healthcare system perspectives in parallel.

Considering potential solutions for limitations and challenges in the health economic evaluation of gene therapies.

INTRODUCTION: The limited evidence in the clinical trials of gene therapies (GTs) posed substantial challenges for a reliable health technology assessment (HTA). This paper provides insights into the relationship between the background of diseases and the health economics assessment of GTs.Areas covered: The impacts of differentiated severity and unmet needs of genetic diseases, on the economic analysis of GTs, were discussed.Expert opinion: GTs offer a potential cure or significant clinical improvement, while limitations in clinical evidence constitute major obstacles for a robust assessment of clinical effectiveness and economic outcomes. This uncertainty may be balanced by the severity of the targeted condition and the associated unmet needs, thus leading to a relatively higher acceptance for GTs. Overtime, HTA agencies will become more demanding on comprehensive evidence of long-term effectiveness. With a growing number of GTs on the horizon, to what extent the unmet needs of previously devastating diseases will be fulfilled remain unclear. Nonetheless, comparative studies, either with a historical control group or existing treatments, will be necessary to demonstrate the additional benefits associated with GTs.

Early Cost-Effectiveness of Onasemnogene Abeparvovec-xioi (Zolgensma) and Nusinersen (Spinraza) Treatment for Spinal Muscular Atrophy I in The Netherlands With Relapse Scenarios.

OBJECTIVES: Onasemnogene Abeparvovec-xioi (AVXS-101) is a gene therapy intended for curative treatment of spinal muscular atrophy (SMA) with an expected price of around €2 000 000. The goal of this study is to perform a cost-effectiveness analysis of treatment of SMA I patients with AVXS-101 in The Netherlands including relapse scenarios. METHODS: An individual-based state-transition model was used to model treatment effect and survival of SMA I patients treated with AVXS-101, nusinersen and best supportive care (BSC). The model included five health states: three health states according to SMA types, one for permanent ventilation and one for death. Deterministic and probabilistic sensitivity analyses were performed. Effects of relapsing to lower health states in the years following treatment was explored. RESULTS: The base-case incremental cost-effectiveness ratio (ICER) for AVXS-101 versus BSC is €138 875/QALY, and €53 447/QALY for AVXS-101 versus nusinersen. If patients relapse within 10 years after treatment with AVXS-101, the ICER can increase up to 6-fold, with effects diminishing thereafter. Only relapses occurring later than 50 years after treatment have a negligible effect on the ICER. To comply with Dutch willingness-to-pay reference values, the price of AVXS-101 must decrease to €680 000. CONCLUSIONS: Based on this model, treatment with AVXS-101 is unlikely to be cost-effective under Dutch willingness-to-pay reference values. Uncertainty regarding the long-term curative properties of AVXS-101 can result in multiplication of the ICER. Decision-makers are advised to appropriately balance these uncertainties against the price they are willing to pay now.

Does Cost-Effectiveness Analysis Overvalue Potential Cures? Exploring Alternative Methods for Applying a "Shared Savings" Approach to Cost Offsets.

OBJECTIVES: To evaluate alternative methods to calculate and/or attribute economic surplus in the cost-effectiveness analysis of single or short-term therapies. METHODS: We performed a systematic literature review of articles describing alternative methods for cost-effectiveness analysis of potentially curative therapies whose assessment using traditional methods may suggest unaffordable valuations owing to the magnitude of estimated long-term quality-adjusted life-year (QALY) gains or cost offsets. Through internal deliberation and discussion with staff at the Health Technology Assessment bodies in England and Canada, we developed the following 3 alternative methods for further evaluation: (1) capping annual costs in the comparator arm at $150 000 per year; (2) "sharing" the economic surplus with the health sector by apportioning only 50% of cost offsets or 50% of cost offsets and QALY gains to the value of the therapy; and (3) crediting the therapy with only 12 years of the average annual cost offsets or cost offsets and QALY gains over the lifetime horizon. The impact of each alternative method was evaluated by applying it in an economic model of 3 hypothetical condition-treatment scenarios meant to reflect a diversity of chronicity and background healthcare costs. RESULTS: The alternative with greatest impact on threshold price for the fatal pediatric condition spinal muscular atrophy type 1 was the 12-year cutoff scenario. For a hypothetical one-time treatment for hemophilia A, capping cost offsets at $150 000 per year had the greatest impact. For chimeric antigen receptor T-cell treatment of non-Hodgkin's lymphoma, capping cost offsets or using 12-year threshold had little impact, whereas 50% sharing of surplus including QALY gains and cost offsets greatly reduced threshold pricing. CONCLUSIONS: Health Technology Assessment bodies and policy makers will wrestle with how to evaluate single or short-term potentially curative therapies and establish pricing and payment mechanisms to ensure sustainability. Scenario analyses using alternative methods for calculating and apportioning economic surplus can provide starkly different assessment results. These methods may stimulate important societal dialogue on fair pricing for these novel treatments.

Cost-effectiveness of a hypothetical cell or gene therapy cure for sickle cell disease.

Sickle cell disease (SCD) is a group of inherited genetic conditions associated with lifelong complications and increased healthcare resource utilization. Standard treatment for SCD in the US varies based on stage of the disease and observed clinical severity. In this study, we aim to evaluate the potential cost-effectiveness of a durable cell or gene therapy cure for sickle cell disease from the US healthcare sector perspective. We developed a lifetime Markov model to evaluate the cost-effectiveness of a hypothetical single-administration durable treatment (DT) for SCD provided at birth, relative to standard of care (SOC). We informed model inputs including direct healthcare costs, health state utility weights, transition probabilities, and mortality rates using a retrospective database analysis of commercially insured individuals and the medical literature. Our primary outcome of interest was the incremental cost-effectiveness ratio (ICER) of DT versus SOC evaluated at a base case willingness-to-pay (WTP) threshold of $150,000 per quality-adjusted life year (QALY). We tested the robustness of our base case findings through scenario, deterministic sensitivity (DSA), and probabilistic sensitivity analyses (PSA). In the base case analysis, treatment with DT was cost-effective with an ICER of $140,877/QALY relative to SOC for a hypothetical cohort involving 47% females. Both males (ICER of $135,574/QALY) and females (ICER of $146,511/QALY) were similarly cost-effective to treat. In univariate DSA the base case ICER was most sensitive to the costs of treating males, DT treatment cost, and the discount rate. In PSA, DT was cost-effective in 32.7%, 66.0%, and 92.6% of 10,000 simulations at WTP values of $100,000, $150,000, and $200,000 per QALY, respectively. A scenario analysis showed cost-effectiveness of DT is highly contingent on assumed lifetime durability of the cure. A hypothetical cell or gene therapy cure for SCD is likely to be cost-effective from the US healthcare sector perspective. Large upfront costs of a single administration cure are offset by significant downstream gains in health for patients treated early in life. We find cost-effectiveness outcomes do not vary substantially by gender; however, several model parameters including assumed durability and upfront cost of DT are likely to influence cost-effectiveness findings.

The cost-effectiveness of gene therapy for severe hemophilia B: a microsimulation study from the United States perspective.

Adeno-associated virus (AAV)-mediated gene therapy is a novel treatment promising to reduce morbidity associated with hemophilia. Although multiple clinical trials continue to evaluate efficacy and safety, limited cost-effectiveness data have been published. This study compared the potential cost-effectiveness of AAV-mediated factor IX (FIX)-Padua gene therapy for patients with severe hemophilia B in the United States vs on-demand FIX replacement and primary FIX prophylaxis, using either standard or extended half-life FIX products. A microsimulation Markov model was constructed, and transition probabilities between health states and utilities were informed by using published data. Costs were aggregated by using a microcosting approach. A time horizon from 18 years old until death, from the perspective of a third-party payer in the United States, was conducted. Gene therapy was more cost-effective than both alternatives considering a $150 000/quality-adjusted life-year threshold. The price for gene therapy was assumed to be $2 000 000 in the base case scenario; however, one of the 1-way sensitivity analyses was conducted by using observed manufacturing, administration, and 5-year follow-up costs of $87 198 for AAV-mediated gene therapy vector as derived from the manufacturing facility and clinical practice at St Jude Children's Research Hospital. One-way sensitivity analyses revealed 10 of 102 scenarios in which gene therapy was not cost-effective compared with alternative treatments. Notably, gene therapy remained cost-effective in a hypothetical scenario in which we estimated that the discounted factor concentrate price was 20% of the wholesale acquisition cost in the United States. Probabilistic sensitivity analysis estimated gene therapy to be cost-effective at 92% of simulations considering a $150 000/quality-adjusted life-year threshold. In conclusion, based on detailed simulation inputs and assumptions, gene therapy was more cost-effective than on-demand treatment and prophylaxis for patients with severe hemophilia B.

Gene therapy may not be as expensive as people think: challenges in assessing the value of single and short-term therapies.

At an upfront price of $2.125 million, the one-time gene therapy onasemnogene abeparvovec for spinal muscular atrophy, a rare neuromuscular disorder that is usually fatal by 2 years of age if untreated, has been called the "most expensive drug ever." This flawed characterization raises important methodological and policy issues regarding valuation of high-cost treatments. We reviewed several other high-cost therapies-with a particular focus on hemophilia A treatment-studied by the nonprofit Institute for Clinical and Economic Review (ICER). In ICER's summary report of 2 treatments for managing hemophilia A, published in this month's JMCP issue, the estimated $15-$18 million lifetime cost of factor VIII is characterized as "far too high," representing "a failure of competition [that] … builds a platform for pricing of treatments … that will only exacerbate these problems." Current literature indicates several factors underlying high factor VIII treatment cost (eg, historical pattern of innovation and lack of market competition) that may also drive the pricing dynamics of advanced therapies for other rare diseases. When a treatment's price is driven high (or "distorted"), an economic principle known as "theory of the second best" suggests that market price becomes a poor estimate of social opportunity cost, and adjustments should be made for such distortions. In any case, a high-cost standard of care creates an opportunity for new technology to generate cost savings, providing an inducement for market entry. Recognizing that this potentially creates a tendency to produce price distortions for new treatments, ICER has attempted to apply some ad hoc adjustments. However, challenges remain in creating a "level playing field" across different disease-modifying or potentially curative innovations (eg, one-time therapy vs ongoing or lifelong treatment with repeated doses). While additional policy work is needed to address this dilemma, it would clearly be misleading to assume that gene therapies are inherently expensive. Rigorous economic evaluation of novel therapies requires careful comparison of lifetime cost and benefits vs standard of care, including adjustments for pricing distortions. Fortunately, economic theory suggests that we could adjust to this circumstance by using the social opportunity costs of interventions based on an appropriate variable cost-effectiveness threshold that would be higher for rare severe diseases. DISCLOSURES: The research reported in this Viewpoints article was funded by Novartis Gene Therapies, Inc. Garrison and Jiao were paid by Novartis Gene Therapies, Inc., to conduct this research. Garrison has also received consulting fees from BioMarin, Inc, and UniQure. Dabbous is a full-time employee of Novartis Gene Therapies, Inc., and holds Novartis stock and stock options.