Cost-Effectiveness Analysis of Tisagenlecleucel in the Treatment of Relapsed or Refractory B-Cell Acute Lymphoblastic Leukaemia in Children and Young Adults in Spain

Economic Evaluations of Chimeric Antigen Receptor T-Cell Therapies for Hematologic and Solid Malignancies: A Systematic Review

OBJECTIVES

This study aimed to systematically review evidence on the cost-effectiveness of chimeric antigen receptor T-cell (CAR-T) therapies for patients with cancer.

METHODS

Electronic databases were searched in October 2022 and updated in September 2023. Systematic reviews, health technology assessments, and economic evaluations that compared costs and effects of CAR-T therapy in patients with cancer were included. Two reviewers independently screened studies, extracted data, synthesized results, and critically appraised studies using the Philips checklist. Cost data were presented in 2022 US dollars.

RESULTS

Our search yielded 1809 records, 47 of which were included. Most of included studies were cost-utility analysis, published between 2018 and 2023, and conducted in the United States. Tisagenlecleucel, axicabtagene ciloleucel, idecabtagene vicleucel, ciltacabtagene autoleucel, lisocabtagene maraleucel, brexucabtagene autoleucel, and relmacabtagene autoleucel were compared with various standard of care chemotherapies. The incremental cost-effectiveness ratio (ICER) for CAR-T therapies ranged from $9424 to $4 124 105 per quality-adjusted life-year (QALY) in adults and from $20 784 to $243 177 per QALY in pediatric patients. Incremental cost-effectiveness ratios were found to improve over longer time horizons or when an earlier cure point was assumed. Most studies failed to meet the Philips checklist due to a lack of head-to-head comparisons and uncertainty surrounding CAR-T costs and curative effects.

CONCLUSIONS

CAR-T therapies were more expensive and generated more QALYs than comparators, but their cost-effectiveness was uncertain and dependent on patient population, cancer type, and model assumptions. This highlights the need for more nuanced economic evaluations and continued research to better understand the value of CAR-T therapies in diverse patient populations.

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.

Evolving Evidence-Based Value Assessment of One-Time Therapies: Tisagenlecleucel as a Case Study

BACKGROUND

Economic evaluation of one-time therapies during reimbursement decision-making is challenging due to uncertain long-term outcomes. The availability of 5-year outcome data from the ELIANA trial and real-world evidence of tisagenlecleucel, the first chimeric antigen receptor T-cell (CAR-T) therapy, presents an opportunity to re-evaluate the predictions of prior cost-effectiveness analyses (CEAs).

OBJECTIVE

To conduct a systematic literature review (SLR) of prior CEAs of tisagenlecleucel for pediatric/young adult relapsed or refractory acute lymphoblastic leukemia (r/r ALL) and evaluate the impact of recently available 5-year efficacy data from ELIANA and advances in CAR-T manufacturing in an updated CEA model.

METHODS

OVID MEDLINE/Embase and health technology assessment (HTA) databases were searched for full-text economic evaluations in English reporting cost-effectiveness results for tisagenlecleucel for r/r ALL. Evaluations with publicly reported incremental cost-effectiveness ratios (ICERs) were included in the SLR. Study screening and data abstraction were conducted following PRISMA guidelines. Data extracted included the country/currency, perspective, clinical trial evidence, model structures, long-term efficacy extrapolation approaches (i.e., overall survival [OS]), time horizon, discount rates, and outcomes (i.e., life years [LY], quality-adjusted LY [QALY], and ICERs). The CEA model reported in Wakase et al. was updated using 5-year OS data from ELIANA and the CAR-T infusion rate informed by real-world practice.

RESULTS

Sixteen records corresponding to 15 unique studies were included in the SLR (11 publications and 5 HTA reports); all were conducted from the health care system perspective of the respective countries. Most studies found tisagenlecleucel to be cost effective, but all studies' projected 3- and 5-year OS rates for tisagenlecleucel were lower than the observed 3- and 5-year rates, respectively, derived from 5-year ELIANA data. When applying updated OS projections from the most recent ELIANA data cut and higher infusion rates of 92.5% (per the real-world infusion rate)-96.0% (per the manufacturer success rate) to the CEA of Wakase et al., the associated QALYs for tisagenlecleucel increased from 11.6 to 14.6-15.0, and LYs increased from 13.3 to 17.0-17.5. Accordingly, the ICERs for tisagenlecleucel decreased from ¥2,035,071 to ¥1,787,988-¥1,789,048 versus blinatumomab and from ¥2,644,702 to ¥2,257,837-¥2,275,181 versus clofarabine combination therapy in the updated CEA model.

CONCLUSIONS AND RELEVANCE

Projections at launch of the likely cost effectiveness of tisagenlecleucel appear to have underestimated its ultimate economic value given more recent trial and real-world data. To balance uncertainty in initial valuation with the need to provide access to novel oncology therapies, payers can consider flexible reimbursement policies alongside ongoing assessments as new data emerge.

Healthcare costs of cancer among children, adolescents, and young adults: A scoping review

OBJECTIVE

To collate and critically review international evidence on the direct health system costs of children and adolescents and young adults (AYA) with cancer.

METHODS

We conducted searches in PubMed, MEDLINE, CINAHL, and Scopus. Articles were limited to studies involving people aged 0-39 years at cancer diagnosis and published from 2012 to 2022. Two reviewers screened the articles and evaluated the studies using the Consolidated Health Economic Evaluation Reporting Standards checklist. The reviewers synthesized the findings using a narrative approach and presented the costs in 2022 US dollars for comparability.

RESULTS

Overall, the mean healthcare costs for all cancers in the 5 years post diagnosis ranged from US$36,670 among children in Korea to US$127,946 among AYA in the USA. During the first year, the mean costs among children 0-14 years ranged from US$34,953 in Chile to over US$130,000 in Canada. These were higher than the costs for AYA, estimated at US$61,855 in Canada. At the end of life, the mean costs were estimated at over US$300,000 among children and US$235,265 among adolescents in Canada. Leukemia was the most expensive cancer type, estimated at US$50,133 in Chile, to US$152,533 among children in Canada. Overall, more than a third of the total cost is related to hospitalizations. All the included studies were of good quality.

CONCLUSIONS

Healthcare costs associated with cancer are substantial among children, and AYA. More research is needed on the cost of cancer in low- and middle-income countries and harmonization of costs across countries.

Cost and cost-effectiveness of immunotherapy in childhood ALL: A systematic review

Survival rates for pediatric acute lymphoblastic leukemia (pALL) have improved dramatically; relapsed/refractory (r/r) acute lymphoblastic leukemia (ALL) remains challenging. Immunotherapies are rapidly evolving treatments for r/r ALL with limited cost-effectiveness data. This study identifies existing economic evaluations of immunotherapy in pALL and summarizes cost-effectiveness. Medline, Embase, and other databases were searched from inception to October 2022. Cost-effectiveness analyses evaluating immunotherapy in pALL were included. Costs reported in 2021 USD. Of 2960 studies, 11 met inclusion criteria. Tisagenlecleucel was compared to standard of care, clofarabine monotherapy, clofarabine combination therapy, or blinatumomab. No studies have evaluated blinatumomab or inotuzumab ozogamicin. Six studies found tisagenlecleucel to be cost-effective, five of which were supported by Novartis. Four found that it had the potential to be cost-effective, and one found that it was not cost-effective. The cost-effectiveness of tisagenlecleucel was highly dependent on list price and cure rates. This study can inform the use of tisagenlecleucel in pALL.

A systematic review on the cost-effectiveness assessment of tisagenlecleucel for refractory or relapsing B-cell acute lymphoblastic leukemia (R/R B-ALL) treatment in children and young adults

BACKGROUND AIMS

The advanced therapy product tisagenlecleucel is a CD19-directed genetically modified autologous T-cell immunotherapy that has brought hope for children and young adults with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). We sought to evaluate the cost-effectiveness of tisagenlecleucel compared with conventional salvage therapies in pediatric and young adult patients with R/R B-ALL.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses parameters as registered in International Prospective Register of Systematic Reviews (CRD42021266998). Literature was searched using the MEDLINE databases via PubMed, EMBASE, Lilacs, the Cochrane Central Register of Controlled Trials and Web of Science in January 2022. Titles were screened independently by two reviewers. Articles deemed to meet the inclusion criteria were screened independently on abstract, and full texts were reviewed.

RESULTS

In total, 5627 publications were identified, from which six eligible studies were selected. The conventional therapies identified were blinatumomab (Blina), clofarabine monotherapy (Clo-M), clofarabine combined with cyclophosphamide and etoposide (Clo-C) and the combination of fludarabine, cytarabine and idarubicin (FLA-IDA). The discounted incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) gained for tisagenlecleucel compared with Clo-C and Blina averages was $38 837 and $25 569, respectively. In relation to the cost of the drug, the average of tisagenlecleucel was approximately 4.3 times, 10.8 times or 4.7 times greater than the Clo-M, Clo-C and Blina, respectively.

CONCLUSIONS

This systematic review highlighted that tisagenlecleucel is a much more expensive therapy than conventional alternatives. However, tisagenlecleucel performed well on the ICER, not exceeding $100 000/QALY. It was also found that the advanced therapy product was more effective than the conventional small molecule and biological drugs, in terms of life years and QALY gained.

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.

Cost effectiveness analysis of CAR-T cell therapy for patients with relapsed/refractory multiple myeloma in China

BACKGROUND

The landscape of treatment strategies for relapsed/refractory multiple myeloma (RRMM) has dramatically changed due to the emergence of chimeric antigen receptor T (CAR-T) cell therapy. The aim of this study was to evaluate the cost-effectiveness of two CAR-T cell treatments for RRMM patients from the perspective of the Chinese healthcare system.

METHODS

Markov model was used to compare currently available salvage chemotherapy with Idecabtagene vicleucel (Ide-cel) and Ciltacabtagene autoleucel (Cilta-cel) for treatment of patients with RRMM. The model was developed based on data from three studies: CARTITUDE-1, KarMMa and MAMMOTH. The healthcare cost and utility of RRMM patients were collected from a provincial clinical center in China.

RESULTS

In the base case analysis, 3.4% and 30.6% of RRMM patients were expected to be long-term survivors after 5 years of Ide-cel and Cilta-cel treatment, respectively. Compared to salvage chemotherapy, Ide-cel and Cilta-cel were associated with incremental QALYs of 1.19 and 3.31, and incremental costs of US $140,693 and $119,806, leading to ICERs of $118,229 and $36,195 per QALY, respectively. At an ICER threshold of $37,653/QALY gained, the probability that Ide-cel and Cilta-cel are cost-effective were estimated to be 0% and 72%, respectively. With younger target people entering the model, and partitioned survival model in scenario analysis, the ICERs of Cilta-cel and Ide-cel changed rather mildly and their cost-effectiveness results were same to base analysis.

CONCLUSIONS

Base on the willingness-to-pay of 3 times China's per capita GDP in 2021, Cilta-cel was considered to be a more cost-effective option compared to salvage chemotherapy for RRMM in China, while Ide-cel was not.

Multidimensional Results and Reflections on CAR-T: The Italian Evidence

The present study aims at defining the economic and organizational impacts of the introduction of chimeric antigen receptor T-cell therapy (CAR-T) in Italy, for the management of diffuse large B-cell lymphoma (DLBCL) patients in third-line therapy, defining the overall level of sustainability for both hospitals and the National Healthcare System (NHS). The analysis focused on CAR-T and Best Salvage Care (in the following BSC), assuming the Italian hospital and NHS perspectives, over a 36-month time horizon. Process mapping and activity-based costing methodologies were applied to collect the hospital costs related to the BSC and CAR-T pathways, including adverse event management. Anonymous administrative data on services provided (diagnostic and laboratory examinations, hospitalizations, outpatient procedures, and therapies) to 47 third-line patients with lymphoma, as well as any organizational investments required, were collected, in two different Italian Hospitals. The economic results showed that the BSC clinical pathway required less resources in comparison with CAR-T (excluding the cost related to the therapy) (BSC: 29,558.41 vs. CAR-T: EUR 71,220.84, -58.5%). The budget impact analysis depicts that the introduction of CAR-T would generate an increase in costs ranging from 15% to 23%, without considering treatment costs. The assessment of the organizational impact reveals that the introduction of CAR-T therapy would require additional investments equal to a minimum of EUR 15,500 to a maximum of EUR 100,897.49, from the hospital perspective. Results show new economic evidence for healthcare decision makers, to optimize the appropriateness of resource allocation. The present analysis suggests the need to introduce a specific reimbursement tariff, both at the hospital and at NHS levels, since no consensus exists, at least in the Italian setting, concerning the proper remuneration for the hospitals who guarantee this innovative pathway, assuming high risks related to timely management of adverse events.

Challenges for Economic Evaluations of Advanced Therapy Medicinal Products: A Systematic Review

OBJECTIVES

Advanced therapy medicinal products (ATMPs) are drugs for human use for the treatment of chronic, degenerative, or life-threatening diseases that are based on genes, tissues, or cells. This article aimed to identify and critically review published economic analyses of ATMPs.

METHODS

A systematic review of economic analyses of ATMPs was undertaken. Study characteristics, design, sources of data, resources and unit costs, modeling and extrapolation methods, study results, and sensitivity analyses were assessed.

RESULTS

A total of 46 economic analyses of ATMP (from 45 articles) were included; 4 were cell therapy medicinal products, 33 gene therapy medicinal products, and 9 tissue-engineered products. 30 therapies had commercial marketing approval; 39 studies were cost-utility analysis, 5 were cost-effectiveness analysis, and 2 were cost only studies. Four studies predicted that the ATMP offered a step change in the management of the condition and 10 studies estimated that the ATMP would offer a lower mean cost.

CONCLUSIONS

Comparison with historical controls, pooling of data, and use of techniques such as mixture cure fraction models should be used cautiously. Sensitivity analyses should be used across a plausible range of prices. Clinical studies need to be designed to align with health technology assessment requirements, including generic quality of life, and payers should aim for clarity of criteria. Regulators and national payers should aim for compatibility of registers to allow interchange of data. Given the increasing reliance on industry-funded economic analyses, careful critical review is recommended.

Costs, effectiveness, and safety associated with Chimeric Antigen Receptor (CAR) T-cell therapy: Results from a comprehensive cancer center

Real world effectiveness, toxicity and costs analyses from chimeric antigen receptor (CAR)-T cell therapy are of utmost relevance to determine whether and how to offer patients highly personalized immunotherapy. In this study, we aimed at describing CAR T-cells effectiveness, safety and costs in a Portuguese Comprehensive Cancer Center. We performed a retrospective descriptive study of adult patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma and transformed follicular lymphoma referred to CAR T-cell therapy, between May 2019 and February 2021. Rates of treatment response, toxicity and survival (Kaplan-Meier method) were analyzed by intention-to-treat. Direct medical costs stratified by inpatient-care, outpatient-care, and diagnostic-therapeutic procedures (DTP) were derived based on resources used and their respective unit costs. In twenty patients (median age 49.5y; 55%male; 70%DLBCL; 50% with primary refractory disease), best overall and complete response rates were 65.0% and 45.0%, respectively. Median overall (OS) and progression-free survivals were 9.2 and 7.3 months; 12-month OS rate was 42.6% (95%CI:23.2-78.3). Grade≥3 cytokine release syndrome and neurotoxicity occurred in 5.6% and 11.1% of patients, respectively. CAR T-cell therapy expenditure, including adverse events costs, was 7 176 196€, or 286 238€ when excluding drug cost. Median cost for treated patient was 355 165€ with CAR T-cell drug cost accounting for 97.0% of the overall expense. Excluding CAR T-cell acquisition cost, inpatient-care and DTP accounted for 57% and 38% of total cost/patient, respectively. Our findings highlight the heavy economic burden of CAR T-cell therapy driven by drug acquisition costs.

The Evolution of Chimeric Antigen Receptor T-Cell Therapy in Children, Adolescents and Young Adults with Acute Lymphoblastic Leukemia

Chimeric antigen receptor T-cell (CAR T) therapy is a revolutionary treatment for pediatric, adolescent and young adult patients (AYA) with relapsed/refractory B-cell acute lymphoblastic leukemia. While the landscape of immunotherapy continues to rapidly evolve, widespread use of CAR T therapy is limited and many questions remain regarding the durability of CAR T therapy, methods to avoid CAR T therapy resistance and the role of consolidative stem cell transplant. Modified strategies to develop effective and persistent CAR T cells at lower costs and decreased toxicities are warranted. In this review we present current indications, limitations and future directions of CAR T therapy for ALL in the pediatric and AYA population.

Tisagenlecleucel for relapsed/refractory acute lymphoblastic leukemia in the Irish healthcare setting: cost-effectiveness and value of information analysis

OBJECTIVES

This study evaluates the cost-effectiveness of tisagenlecleucel (a CAR T-cell therapy), versus blinatumomab, for the treatment of pediatric and young adult patients with relapsed/refractory acute lymphoblastic leukemia (R/R ALL) in the Irish healthcare setting. The value of conducting further research, to investigate the value of uncertainty associated with the decision problem, is assessed by means of expected value of perfect information (EVPI) and partial EVPI (EVPPI) analyses.

METHODS

A three-state partitioned survival model was developed. A short-term decision tree partitioned patients in the tisagenlecleucel arm according to infusion status. Survival was extrapolated to 60 months; general population mortality with a standardized mortality ratio was then applied. Estimated EVPI and EVPPI were scaled up to population according to the incidence of the decision.

RESULTS

At list prices, the incremental cost-effectiveness ratio was EUR 73,086 per quality-adjusted life year (QALY) (incremental costs EUR 156,928; incremental QALYs 2.15). The probability of cost-effectiveness, at the willingness-to-pay threshold of EUR 45,000 per QALY, was 16 percent. At this threshold, population EVPI was EUR 314,455; population EVPPI was below EUR 100,000 for each parameter category.

CONCLUSIONS

Tisagenlecleucel is not cost effective, versus blinatumomab, for the treatment of pediatric and young adult patients with R/R ALL in Ireland (at list prices). Further research to decrease decision (parameter) uncertainty, at the defined willingness-to-pay threshold, may not be of value. However, there is a high degree of uncertainty underpinning the analysis, which may not be captured by EVPI analysis.

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 review of costs and cost-effectiveness of treatment for relapsed/refractory acute leukaemia in children and young adults

INTRODUCTION

Survival outcomes of children with relapsed/refractory (r/r) acute leukaemia remain poor. Novel expensive treatments have been developed to improve their outcomes, yet, limited evidence exists about cost-effectiveness of alternative treatment strategies.

AREAS COVERED

A systematic review was conducted to summarize the health-economic evidence about costs/cost-effectiveness of treating r/r acute leukaemia in children/young adults. We searched Medline, Embase, and Cochrane databases until August 13^th, 2021. Eligible articles included peer-reviewed original studies addressing r/r paediatric/young-adult acute lymphoblastic leukaemia (ALL), and acute myeloid leukaemia (AML). Quality assessment was conducted using Consolidated Health Economics Evaluation Reporting Standards (CHEERS) checklist.

EXPERT OPINION

The majority of papers focused on CAR-T cell therapy, which is still a novel treatment for r/r ALL, and was found to be cost-effective, yet, there remain concerns over its long-term effectiveness, affordability, and equity in access. The next best treatment option is Blinatumomab, followed by Clofarabine therapy, whereas FLA-IDA salvage chemotherapy provides least value for money. The quality of evidence is moderate to high, with limited generalizability of findings due to high variability in outcomes obtained from modelling studies. Limited studies evaluated r/r AML. We provide recommendations to deliver cost-effective treatments in real-world contexts, with implications for healthcare policy and practice.

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.

Economic Evidence on Potentially Curative Gene Therapy Products: A Systematic Literature Review

OBJECTIVE

The aim of this review was to summarize all available evidence on the cost effectiveness of potentially curative gene therapies and identify challenges that economic evaluations face in this area.

METHODS

We conducted a systematic review of four databases (PubMed/MEDLINE, Embase, CINAHL, EconLit) and grey literature sources. We conducted the search on August 23, 2019 and updated it on November 26, 2020. We included all English, French and Spanish language studies that addressed a gene therapy that had received regulatory approval or had entered a phase III trial, and also reported on costs related to the therapy. Critical appraisal was conducted to assess quality of reporting in included studies.

RESULTS

Fifty-six studies were identified. Of the 42 full economic evaluations, 71% (n = 30) evaluated chimeric antigen receptor T-cell therapies, most used either a Markov model (n = 17, 40%) and/or a partitioned survival model (n = 17, 40%), and 76% (n = 32) adopted a public or private payer perspective. The model characteristics with the greatest impact on cost effectiveness included assumptions about the efficacy of the treatment and the comparators used.

CONCLUSION

All gene therapies in this review were shown to be more effective than their comparators, although due to high costs not all were considered cost effective at standard cost-effectiveness thresholds. Despite their high cost, some gene therapies have the potential to dominate the alternatives in conditions with high mortality/disability. The choice of comparator and assumptions regarding long-term effectiveness had substantial impacts on cost-effectiveness estimates and need to be carefully considered. Both the quality of inputs and the quality of reporting were highly variable.

Applying State-of-the-Art Survival Extrapolation Techniques to the Evaluation of CAR-T Therapies: Evidence from a Systematic Literature Review

INTRODUCTION

Traditional statistical techniques for extrapolating short-term survival data for anticancer therapies assume the same mortality rate for noncured and "cured" patients, which is appropriate for projecting survival of non-curative therapies but may lead to an underestimation of the treatment effectiveness for potentially curative therapies. Our objective was to ascertain research trends in survival extrapolation techniques used to project the survival benefits of chimeric antigen receptor T cell (CAR-T) therapies.

METHODS

A global systematic literature search produced a review of survival analyses of CAR-T therapies, published between January 1, 2015 and December 14, 2020, based on publications sourced from MEDLINE, scientific conferences, and health technology assessment agencies. Trends in survival extrapolation techniques used, and the rationale for selecting advanced techniques, are discussed.

RESULTS

Twenty publications were included, the majority of which (65%, N = 13) accounted for curative intent of CAR-T therapies through the use of advanced extrapolation techniques, i.e., mixture cure models [MCMs] (N = 10) or spline-based models (N = 3). The authors' rationale for using the MCM approach included (a) better statistical fits to the observed Kaplan-Meier curves (KMs) and (b) visual inspection of the KMs indicated that a proportion of patients experienced long-term remission and survival which is not inherently captured in standard parametric distributions.

DISCUSSION

Our findings suggest that an advanced extrapolation technique should be considered in base case survival analyses of CAR-T therapies when extrapolating short-term survival data to long-term horizons extending beyond the clinical trial duration.

CONCLUSION

Advanced extrapolation techniques allow researchers to account for the proportion of patients with an observed plateau in survival from clinical trial data; by only using standard-partitioned modeling, researchers may risk underestimating the survival benefits for the subset of patients with long-term remission. Sensitivity analysis with an alternative advanced extrapolation technique should be implemented and re-assessment using clinical trial extension data and/or real-world data should be conducted as longer-term data become available.