Health economic evaluation of gene replacement therapies: methodological issues and recommendations

Market Access Challenges and Solutions in Cell and Gene Therapy in The Netherlands

With the increasing pipeline of cell and gene therapies (CGTs) and the expected surge in the number of approvals, understanding the market access landscape becomes crucial for timely patient access. This study evaluates the challenges Dutch stakeholders encounter in CGT market access, offering insights for improving time-to-patient access. A traditional literature review was conducted to identify market access challenges and solutions for CGTs. Based on the findings, participants for semi-structured interviews, designed using an interview guide adapted to the Dutch context, were selected to capture diverse perspectives on market access. This review included 124 relevant articles out of 2449, covering several aspects of market access of CGTs. Subsequently, interviews with 16 stakeholders from academia, patient advocacy groups, manufacturers, health insurers, payers, hospital pharmacists, healthcare practitioners, and the Association of Innovative Medicines were conducted. Stakeholders identified challenges and proposed solutions for reimbursement package management, clinical trials, health economics, payment models, and procedural and organisational aspects. Thematic analysis revealed unique country-specific challenges and solutions in the Netherlands. This research provides insights into these challenges and potential solutions, emphasising the need for collaborative efforts among stakeholders to develop practical and multidisciplinary measures to improve the market access landscape for CGTs in the country.

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.

Using automated text classification to explore uncertainty in NICE appraisals for drugs for rare diseases

OBJECTIVE

This study examined the application, feasibility, and validity of supervised learning models for text classification in appraisals for rare disease treatments (RDTs) in relation to uncertainty, and analyzed differences between appraisals based on the classification results.

METHODS

We analyzed appraisals for RDTs (n = 94) published by the National Institute for Health and Care Excellence (NICE) between January 2011 and May 2023. We used Naïve Bayes, Lasso, and Support Vector Machine models in a binary text classification task (classifying paragraphs as either referencing uncertainty in the evidence base or not). To illustrate the results, we tested hypotheses in relation to the appraisal guidance, advanced therapy medicinal product (ATMP) status, disease area, and age group.

RESULTS

The best performing (Lasso) model achieved 83.6 percent classification accuracy (sensitivity = 74.4 percent, specificity = 92.6 percent). Paragraphs classified as referencing uncertainty were significantly more likely to arise in highly specialized technology (HST) appraisals compared to appraisals from the technology appraisal (TA) guidance (adjusted odds ratio = 1.44, 95 percent CI 1.09, 1.90, p = 0.004). There was no significant association between paragraphs classified as referencing uncertainty and appraisals for ATMPs, non-oncology RDTs, and RDTs indicated for children only or adults and children. These results were robust to the threshold value used for classifying paragraphs but were sensitive to the choice of classification model.

CONCLUSION

Using supervised learning models for text classification in NICE appraisals for RDTs is feasible, but the results of downstream analyses may be sensitive to the choice of classification model.

Analysis of the Gene Therapies Authorized by the United States Food and Drug Administration and the European Medicines Agency

BACKGROUND

Gene therapy, altering the genes inside human cells, has recently emerged as an alternative for preventing and treating disease. Concerns have been expressed about the clinical value and the high cost of gene therapies.

OBJECTIVE

This study assessed the characteristics of the clinical trials, authorizations, and prices of gene therapies in the United States and the European Union.

RESEARCH DESIGN

We collected regulatory information from the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) and manufacturer-listed prices from the United States, UK, and Germany. Descriptive statistics and t tests were conducted in the study.

RESULTS

As of January 1, 2022, the FDA and EMA authorized 8 and 10 gene therapies, respectively. The FDA and EMA granted orphan designation to all gene therapies except talimogene laherparepvec. Pivotal clinical trials were nonrandomized, open level, uncontrolled, phase I-III, and included a limited number of patients. Study primary outcomes were mainly surrogate endpoints without demonstration of direct patient benefit. The price of gene therapies at market entry ranged from $200,064 to $2,125,000 million.

CONCLUSIONS

Gene therapy is used to treat incurable diseases that affect only a small number of patients (orphan diseases). Based on this, they are approved by the EMA and FDA with insufficient clinical evidence to ensure safety and efficacy, in addition to the high cost.

Capturing the Impact of Constraints on the Cost-Effectiveness of Cell and Gene Therapies: A Systematic Review

OBJECTIVE

Decision-makers need to resolve constraints on delivering cell and gene therapies to patients as these treatments move into routine care. This study aimed to investigate if, and how, constraints that affect the expected cost and health consequences of cell and gene therapies have been included in published examples of cost-effectiveness analyses (CEAs).

METHOD

A systematic review identified CEAs of cell and gene therapies. Studies were identified from previous systematic reviews and by searching Medline and Embase until 21 January 2022. Constraints described qualitatively were categorised by theme and summarised by a narrative synthesis. Constraints evaluated in quantitative scenario analyses were appraised by whether they changed the decision to recommend treatment.

RESULTS

Thirty-two CEAs of cell (n = 20) and gene therapies (n = 12) were included. Twenty-one studies described constraints qualitatively (70% cell therapy CEAs; 58% gene therapy CEAs). Qualitative constraints were categorised by four themes: single payment models; long-term affordability; delivery by providers; manufacturing capability. Thirteen studies assessed constraints quantitatively (60% cell therapy CEAs; 8% gene therapy CEAs). Two types of constraint were assessed quantitatively across four jurisdictions (USA, Canada, Singapore, The Netherlands): alternatives to single payment models (n = 9 scenario analyses); improving manufacturing (n = 12 scenario analyses). The impact on decision-making was determined by whether the estimated incremental cost-effectiveness ratios crossed a relevant cost-effectiveness threshold for each jurisdiction (outcome-based payment models: n = 25 threshold comparisons made, 28% decisions changed; improving manufacturing: n = 24 threshold comparisons made, 4% decisions changed).

CONCLUSION

The net health impact of constraints is vital evidence to help decision-makers scale up the delivery of cell and gene therapies as patient volume increases and more advanced therapy medicinal products are launched. CEAs will be essential to quantify how constraints affect the cost-effectiveness of care, prioritise constraints to be resolved, and establish the value of strategies to implement cell and gene therapies by accounting for their health opportunity cost.

How are health technology assessment bodies responding to the assessment challenges posed by cell and gene therapy?

BACKGROUND

The aims of this research were to provide a better understanding of the specific evidence needs for assessment of clinical and cost-effectiveness of cell and gene therapies, and to explore the extent that the relevant categories of evidence are considered in health technology assessment (HTA) processes.

METHODS

A targeted literature review was conducted to identify the specific categories of evidence relevant to the assessment of these therapies. Forty-six HTA reports for 9 products in 10 cell and gene therapy indications across 8 jurisdictions were analysed to determine the extent to which various items of evidence were considered.

RESULTS

The items to which the HTA bodies reacted positively were: treatment was for a rare disease or serious condition, lack of alternative therapies, evidence indicating substantial health gains, and when alternative payment models could be agreed. The items to which they reacted negatively were: use of unvalidated surrogate endpoints, single arm trials without an adequately matched alternative therapy, inadequate reporting of adverse consequences and risks, short length of follow-up in clinical trials, extrapolating to long-term outcomes, and uncertainty around the economic estimates.

CONCLUSIONS

The consideration by HTA bodies of evidence relating to the particular features of cell and gene therapies is variable. Several suggestions are made for addressing the assessment challenges posed by these therapies. Jurisdictions conducting HTAs of these therapies can consider whether these suggestions could be incorporated within their existing approach through strengthening deliberative decision-making or performing additional analyses.

A review of economic issues for gene-targeted therapies: Value, affordability, and access

The National Center for Advancing Translational Sciences' virtual 2021 conference on gene-targeted therapies (GTTs) encouraged multidisciplinary dialogue on a wide range of GTT topic areas. Each of three parallel working groups included social scientists and clinical scientists, and the three major sessions included a presentation on economic issues related to their focus area. These experts also coordinated their efforts across the three groups. The economics-related presentations covered three areas with some overlap: (1) value assessment, uncertainty, and dynamic efficiency; (2) affordability, pricing, and financing; and (3) evidence generation, coverage, and access. This article provides a synopsis of three presentations, some of their key recommendations, and an update on related developments in the past year. The key high-level findings are that GTTs present unique data and policy challenges, and that existing regulatory, health technology assessment, as well as payment and financing systems will need to adapt. But these adjustments can build on our existing foundation of regulatory and incentive systems for innovation, and much can be done to accelerate progress in GTTs. Given the substantial unmet medical need that exists for these oft-neglected patients suffering from rare diseases, it would be a tragedy to not leverage these exciting scientific advances in GTTs.

Gene Therapy for Neuromuscular Diseases: Health Economic Challenges and Future Perspectives

Highly efficacious, potentially curative gene therapies holds immense clinical promise, but also present complex challenges. At the time of regulatory approval and health technology assessment (HTA), evidence of efficacy and safety of gene therapies is often uncertain. In addition, research, development, and manufacturing costs, small pools of eligible patients, and the fact that many gene therapies are administered only once means that they frequently are associated with very high “one-off” price points. Although only a limited number of products have been brought to market globally, hundreds of clinical trials of gene therapies, including several of monogenetic neuromuscular diseases, are currently ongoing. Over time, as more and more conditions become amendable to gene therapy, the number of transformative, high-cost treatments is likely to increase considerably. For these reasons, concerns have been raised regarding the suitability of current health policy systems, including HTA frameworks, in ensuring appropriate access to these therapeutic innovations while simultaneously safeguarding value for taxpayers’ money, as well as affordability and sustainability. This review provides a summary overview of current challenges and future perspectives of gene therapies for neuromuscular diseases from a health economic point of view.

Critical Reflections on Reimbursement and Access of Advanced Therapies

Background: The health economic literature has questioned the cost-effectiveness and affordability of advanced therapies, proposed adjustments to value assessment frameworks, and discussed the use of outcome-based managed entry agreements and staggered payments in the last few years. The aim of this manuscript is to conduct a critical reflection on assessment criteria and access conditions for reimbursement of advanced therapies.

Methods: A narrative review of the peer-reviewed literature and grey literature was conducted in April 2021 by searching PubMed; Google Scholar; policy and legislative documents; websites of health technology assessment agencies, advanced therapy organisations, governmental advanced therapy innovation programmes, consultancy agencies; ISPOR conference abstracts and presentations.

Results: Based on the available evidence, this manuscript argues that: a) advanced therapies can be cost-effective at high prices set by manufacturers; b) the economic evaluation framework adopted by many payers under-values these products; c) advanced therapies can be affordable and may not require spread payments; d) outcome-based managed entry agreements are theoretically attractive, but challenging in practice; e) the cost-effectiveness of advanced therapies depends on the outcome-based managed entry agreement and payment approach; f) there is a role for multinational collaborations to manage reimbursement and access of advanced therapies.

Conclusions: This manuscript shows that there is no single approach to reimbursement and access of advanced therapies. Instead, we support a more tailored assessment of health economic aspects of advanced therapies, which considers the heterogeneity of these products and their target populations.

Systematic Literature Review of Clinical and Economic Evidence for Spinal Muscular Atrophy

INTRODUCTION

The recent advent of disease-modifying therapies (DMTs) has dramatically changed the treatment landscape of spinal muscular atrophy (SMA), and the multifaceted impact of this advancement has not been assessed thoroughly in the growing body of literature. We sought to summarize the literature on the natural history of SMA and the impact of SMA DMTs, including health-related quality of life (HRQOL) and utilities, clinical efficacy and safety, and economic impact.

METHODS

Systematic literature reviews were conducted following PRISMA guidelines with no inclusive dates. Relevant studies were identified by searching full-text databases on November 12-13, 2020, including MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and EconLit, conference proceedings, health technology assessment databases, and clinical trial registries. All searches used a combination of MeSH and key terms. Studies were screened according to criteria based upon population, intervention, outcomes, and study design structure.

RESULTS

Findings from 17, 23, 32, and 42 studies were included for the evaluation of natural history of SMA, HRQOL and utilities, clinical efficacy and safety, and economic impact of DMTs, respectively. Currently available data indicate that untreated SMA is associated with considerable humanistic and economic burden, with estimates of costs varying by treatment. While a variety of interventions have been evaluated in SMA clinical trials, quantitative synthesis of safety and efficacy findings was not feasible because of inconsistencies in reported outcomes. Data assessing impacts of DMTs on HRQOL were also lacking.

CONCLUSIONS

Overall, this systematic literature review highlights a clear need for up-to-date and methodologically rigorous clinical, HRQOL, and economic data to support unbiased assessments of the relative clinical and economic effectiveness of SMA treatments. More research is required to extend our understanding of the burden of SMA on HRQOL utility assessments and the impact of new DMTs on HRQOL and utilities for patients with SMA.

Onasemnogene abeparvovec for the treatment of spinal muscular atrophy

INTRODUCTION

Gene therapy for spinal muscular atrophy (SMA) represents a significant milestone in the treatment of neurologic diseases. SMA is a neurodegenerative disease that results in motor neuron loss because of mutations of the survival motor neuron 1 gene, which directs survival motor neuron (SMN) protein production. Onasemnogene abeparvovec, a one-time gene replacement therapy, delivers a functional transgene to restore SMN protein expression. Onasemnogene abeparvovec has demonstrated improved survival and motor milestone achievements for presymptomatic infants and patients with SMA type 1.

AREAS COVERED

This expert review describes the current state of gene therapy for SMA, reviews the mechanism of and clinical experience with onasemnogene abeparvovec, explains future efforts to expand applications of gene therapy for SMA, and provides context for developing gene therapy for other conditions.

EXPERT OPINION

Onasemnogene abeparvovec has demonstrated efficacy in clinical trials and, because of this, is a valuable treatment option for patients with symptomatic infantile SMA and those identified by newborn screening. Gene therapy is still in its infancy, and challenges and uncertainties associated with transgene delivery must be addressed. With ongoing development of vector technology, more specific tissue tropism, reduced "off-target" effects, and an enhanced safety profile will continue to evolve.

Gene Therapy Evidence Generation and Economic Analysis: Pragmatic Considerations to Facilitate Fit-for-Purpose Health Technology Assessment

Gene therapies (GTs) are considered to be a paradigm-shifting class of treatments with the potential to treat previously incurable diseases or those with significant unmet treatment needs. However, considerable challenges remain in their health technology assessment (HTA), mainly stemming from the inability to perform robust clinical trials to convince decision-makers to pay the high prices for the potential long-term treatment benefits provided. This article aims to review the recommendations that have been published for evidence generation and economic analysis for GTs against the feasibility of their implementation within current HTA decision analysis frameworks. After reviewing the systematically identified literature, we found that questions remain on the appropriateness of GT evidence generation, considering that additional, broader values brought by GTs seem insufficiently incorporated within proposed analytic methods. In cases where innovative methods are proposed, HTA organizations remain highly conservative and resistant to change their reference case and decision analysis framework. Such resistances are largely attributed to the substantial evidence uncertainty, resource-consuming administration process, and the absence of consensus on the optimized methodology to balance all the advantages and potential pitfalls of GTs.

Challenges in the market access of regenerative medicines, and implications for manufacturers and decision-makers: a systematic review

Aim: Regenerative medicines (RMs) are expected to transform the treatment paradigm of rare, life-threatening diseases, while substantial challenges impede its market access. This study aimed to present these challenges. Materials & methods: Publications identified in the Medline and Embase databases until December 2020 were included. Results: Uncertainties around the relative effectiveness and long-term benefits of RMs are most scrutinized. A new reference case for RMs is questionable, but examining impacts of study perspective, time horizon, discount rate and extrapolation methods on estimates is advised. Establishing reasonable prices of RMs requires increased transparency in the development costs and better values measurements. Outcome-based payments require considerable investments and potential legislative adjustments. Conclusion: Greater flexibility for health technology assessment and economic analyses of RMs is necessary. This comprehensive review may prompt more multi-stakeholder conversations to discuss the optimized strategy for value assessment, pricing and payment in order to accelerate the market access of RMs.

Medicine characteristics affecting the time to guidance publication by National Institute for Health and Care Excellence in the single technology appraisal process

OBJECTIVE

In England, the time gap between marketing authorization (MA) and guidance publication by National Institute for Health and Care Excellence (NICE) can limit patients' access to new medicines. In this study, our aim was to identify medicine characteristics associated with the long time gap between MA and guidance publication and explore the influencing factors.

METHODS

We identified 116 single technology appraisals from 2016 to 2020 using publicly available data, and extracted information on the year of appraisal completion, application type, experiences of similar appraisals, orphan medicinal products (OMPs), cancer medicines, and accelerated assessment. Multiple regression analyses were performed to analyze the associations between the medicine characteristics and key time periods related to health technology assessment and MA processes.

RESULTS

OMPs were associated with a long period between MA and guidance publication. Specifically, OMPs and cancer medicines were associated with slow guidance publication after the final scope (FS) development. However, there was no association between OMPs and the period between validation of MA application and FS development. Non-double-blinded randomized clinical trials and the use of comparators not specified in the FS were associated with slow guidance publication after the FS development.

CONCLUSIONS

Our results demonstrate that OMPs are associated with a longer period between MA and guidance publication by the NICE than non-OMPs; this may be attributed to the slow guidance publication after the FS development. These findings indicate the necessity to shorten the appraisal process for OMPs.

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.

Partnership agreements for regenerative medicines: a database analysis and implications for future innovation

Aim: Partnerships have been leveraged to advance the regenerative medicines (RMs) development. This study analyzed the evolution of partnership landscape for regenerative medicines (RMs). Methods: Partnership agreements publicly announced from January 2014 - June 2020 were described. Results: 1169 partnership agreements with total amount of US$63,496 million were identified. Most agreements concerned RMs that were for oncology (25.3%), in the discovery or preclinical phase (66.9%) and gene-based products (45.3%). The most common partnership type is collaborative agreements without licensing. The partnerships between 'biotechnology companies and not-for-profit organizations' represented the largest number (n = 416; 35.6%). 'Big Pharma' preferred collaboration and licensing agreements with a higher amount. Conclusion: Collaborations between highly specialized players with complementary expertise promote the successful translation of scientific discovery to RMs.

Do Advanced Therapies Have a Future in the Low- and Middle-Income Countries - The Case of Bulgaria, Romania, and Poland

Introduction: The significant therapeutic potential of the advanced therapies (ATs) has predetermined the increased interests in their development mainly in the context of rare diseases most of which are genetically determined. However, there are still many challenges in front of the health insurance funds related to the cost-effectiveness and budget impact issues of these therapies. Our aim was to review and analyze the potential of low- and middle-income countries for health technology assessment (HTA) of advanced therapies focusing on Bulgaria, Romania and Poland as reference countries. A literature review of the existing good practices related to HTA of advanced therapies across the world and comparison with the national reality were performed. A list of challenges and issues from the point of view of the payer institution of all analyzed countries was performed. Pilot recommendations on how to overcome the barriers were created based on the existing practices and the potential of the national system. Discussion: 15 out of 80 articles identified in PubMed were found as applicable to the study scope as most of them were published in the period 2019-2021. Undoubtedly, the main challenges correspond to the high treatment costs, the uncertainty in clinical effectiveness, and poor HTA methodological approaches applicable for ATs worldwide. The issues identified for low and middle-income countries are similar having as well the lack of enough qualified health economists for the purposes of assessment and appraisal of HTA dossiers of the advanced therapies, lack of adequate existing separate financial programs for those therapies, and not preparedness of the health system and the society as a whole for such therapies. Conclusions: Despite the difficulties and challenges, the advanced therapies can be defined as a futuristic therapy for which great discoveries are yet to come. Therefore, each country should consider the implementation of reliable and nationally oriented programs for HTA and adequate financial coverage of these therapies.

The impact of COVID-19 on the cell and gene therapies industry: Disruptions, opportunities, and future prospects

Coronavirus 2019 (COVID-19) has caused significant disruption to the cell and gene therapy (CGT) industry, which has historically faced substantial complexities in supply of materials, and manufacturing and logistics processes. As decision-makers shifted their priorities to COVID-19-related issues, the challenges in market authorisation, and price and reimbursement of CGTs were amplified. Nevertheless, it is encouraging to see that some CGT developers are adapting their efforts toward the development of promising COVID-19-related therapeutics and vaccines. Manufacturing resilience, digitalisation, telemedicine, value-based pricing, and innovative payment mechanisms will be increasingly harnessed to ensure that market access of CGTs is not severely disrupted.