A systematic review of economic evaluations of enzyme replacement therapy in Lysosomal storage diseases

Assessing the Value for Money of Enzyme Replacement Therapy in Gaucher Disease Types 1 and 3b: Can Expanded Coverage Be Justified?

BACKGROUND AND OBJECTIVES

The Health Intervention and Technology Assessment Program was commissioned to conduct a cost-utility and budget impact analysis of enzyme replacement therapy (ERT) for Gaucher disease types 1 and 3b. The findings from this assessment are to support the decision-making process regarding the potential expansion of ERT coverage within Thailand's public health system.

METHODS

The analysis compared the current policy, which provides treatment with imiglucerase only for patients with Gaucher disease type 1, as listed in the National List of Essential Medicine, with a proposed policy that extends coverage to include Gaucher disease types 1 and 3b with either imiglucerase or velaglucerase. Cost-utility analysis of these policy options was performed using decision tree and Markov models over a lifetime horizon from a societal perspective. The financial implications for the relevant budgetary authority over 5 years were estimated. The research methodology adheres rigorously to Thailand's health technology assessment guidelines.

RESULTS

The study found that the incremental cost-effectiveness ratios for treating both Gaucher disease types 1 and 3b are 6,769,000 and 9,359,000 baht per quality-adjusted life year (QALY) for imiglucerase and velaglucerase, respectively, which is well beyond Thailand's cost-effectiveness threshold of 160,000 baht per QALY. Such an expansion would incur an additional budgetary burden of approximately 81 million baht for imiglucerase and 138 million baht for velaglucerase. Increasing the rate of hematopoietic stem cell transplantation (HSCT) can improve the cost-effectiveness of the expansion.

CONCLUSIONS

The study concludes that expanding ERT with either imiglucerase or velaglucerase to treat both Gaucher disease types 1 and 3b is not cost-effective at current prices in Thailand; however, it could become cost-effective with a reduction of approximately 60% in drug prices or if all eligible patients undergo HSCT.

Cost-effectiveness analysis of enzyme replacement therapy for the treatment of Chinese patients with fabry disease: a Markov model

Background

Fabry disease (FD) is an X-chromosome-linked genetic disorder. Currently, the main treatments for FD include disease-nonspecific and disease-specific treatments. Nonspecific treatment involves symptomatic management of organ involvement. On the other hand, disease-specific treatment is to regulate the activity of the corresponding enzymes, which is targeted. Among them, enzyme replacement therapy (ERT) is a classical therapy. Several studies have demonstrated the significant ameliorative effect of agalactosidase-α (ALTA-a) on cardiac and renal function in patients with FD. Despite the excellent clinical performance, there are limited pharmacoeconomic studies on ERT for FD worldwide.

Objective

The aim of this study was to analyze the cost-effectiveness of ERT for FD in China from the perspective of the healthcare system.

Methods

We constructed a five-state Markov model based on the disease characteristics of FD. The modeling period was 1 month. The time horizon was 3 years. The willingness-to-pay threshold was chosen as 1-3 times the gross national product (GDP) per capita. The incremental cost-effectiveness ratio (ICER) was calculated from the base case analysis, and one-way sensitivity analysis and probabilistic sensitivity analysis were performed.

Results

The ICER value is ¥148071.95/QALY, which is between 1-3 times GDP per capita. The sensitivity analysis showed that the cost of ALTA-a had a significant effect on ICER and proved the stability of the results.

Conclusion

ERT therapy is a cost-effective program compared to "No ERT" therapy.

Health State Utility Values in Fabry Disease: Insights from the Pegunigalsidase Alfa Clinical Trials

INTRODUCTION

Fabry disease (FD) is a rare lysosomal storage disorder that is associated with pain and progressive damage to the renal, cardiac, and cerebrovascular systems. Enzyme replacement therapy (ERT) is one of the treatment options for FD and the most recently approved ERT agent, pegunigalsidase alfa, has shown clinical efficacy in three phase 3 clinical trials of adults with FD: BALANCE, BRIDGE, and BRIGHT. Recent published guidelines support the mapping of health utility state data to the EuroQol-5 Dimension-3 Level (EQ-5D-3L) index to align with the preferred methodology used by the National Institute for Health and Care Excellence (NICE). Therefore, the primary objective of this study was to estimate EQ-5D-3L values in clinical trials of pegunigalsidase alfa for FD for future cost-utility analyses.

METHODS

A mixed effects model was developed to predict values derived from EQ-5D-3L for the following health states used in cost-utility analyses: no Fabry clinical event (FCE)/no pain-related adverse event (AE), pain-related AE, cardiac FCE, cerebrovascular FCE, and renal FCE.

RESULTS

The baseline EQ-5D-3L utility value had a statistically significant (p < 0.0001) impact on utility values, whereas study, age, sex, disease type, treatment arm, kidney function, and serious AE were not statistically significant. Health state utility values with 95% confidence intervals (CI) for the final model were as follows: no FCE/no pain-related AE, 0.8005 (0.7675, 0.8334); pain-related AE, 0.7737 (0.7262, 0.8211); cardiac FCE, 0.7189 (0.6274, 0.8103); cerebrovascular FCE, 0.7923 (0.6633, 0.9212); and renal FCE, 0.6881 (0.3887, 0.9874).

CONCLUSIONS

The utility values generated by the present study are generally in line with EQ-5D values in the FD literature and can be used to inform both economic evaluations and our understanding of the impact that FD has on quality of life.

TRIAL REGISTRATION

NCT03018730, NCT02795676, NCT03180840.

Clinical insights in enzyme replacement therapy for metabolic storage disorders: lessons from Pompe disease

Metabolic storage disorders, including lysosomal storage disorders, pose complex challenges in management due to their progressive and life-threatening nature. Although enzyme replacement therapy has substantially improved outcomes for patients with lysosomal storage disorders, limitations of this therapy have become apparent throughout two decades of use. New clinical features of these diseases have emerged as patients live longer, leading to unresolved questions regarding ongoing treatment and long-term care. Innovative therapies are emerging that aim to improve targeting of tissues, particularly for previously inaccessible areas such as the CNS. These next-generation treatments hold promise for enhancing patient outcomes beyond what enzyme replacement therapy can do. Continued exploration of novel therapeutic strategies will be crucial for providing more effective and personalised care for these complex diseases.

Cost-Effectiveness Analysis of Idursulfase for the Long-Term Treatment of Hunter Syndrome Using a Partitioned-Survival Model Approach in R

OBJECTIVES

Hunter syndrome is among the costliest life-long genetic conditions associated with a substantial burden-of-illness and a significant impact on the health systems, families, and society. We estimated the cost-effectiveness of long-term enzyme replacement therapy with idursulfase versus the standard of care from a societal perspective using a streamlined modeling strategy in R.

METHODS

A de novo 4-state partitioned survival model was developed to compare lifetime cost and outcomes of 2 care models operationalized in R. The disease progression was based on independent survival modeling of relevant Kaplan-Meier data. The healthcare and out-of-pocket costs were drawn from the local setting. The quality of life was measured using the EQ5D5L and the time trade-off valuation of health-state vignettes that match the states in the model. Probabilistic and deterministic sensitivity analyses were conducted to test the uncertainty around the model results.

RESULTS

The lifetime incremental quality-adjusted life years were 4.1 years (95% CI, 2.37-5.68). Incremental costs were estimated to be $9.5 million (95% CI, 9.0 million-10.0 million), which primarily consists of drug costs (99%). The incremental costs per quality-adjusted life year were estimated to be approximately $2.4 million (95% CI, 1.7 million-3.8 million). Sensitivity analyses showed that the key drivers of incremental cost-effectiveness ratio were quality of life in the preprogression state and differential discounting approach, besides the acquisition cost of enzyme replacement therapy of idursulfase.

CONCLUSIONS

The incremental cost-effectiveness ratios were beyond any conventionally used cost-effectiveness threshold in all cases. At the current price, there is a significant discrepancy between the therapy's funding decision and the cost-effectiveness assessment as a basis for guiding healthcare prioritization in Malaysia.

Pancreatic exocrine insufficiency after pancreatic resection: a systematic review

INTRODUCTION

Pancreatic exocrine insufficiency (PEI) is a condition defined by a reduction in pancreatic exocrine activity that impairs normal digestion. Despite established guidelines recommendations, precise diagnosis of PEI after pancreatic resection are infrequently achieved. This review aims to provide a comprehensive overview of the methodology and accuracy of diagnostic tools available for evaluating PEI after pancreatic resection.

METHODS

A review of PEI diagnostic tests was conducted using a combined text and MeSH search strategy to identify relevant articles focused on post-pancreatectomy PEI diagnosis.

RESULTS

The literature search yielded 4,874 records, and 30 studies were included in the analysis, with a total of 2,305 patients. The reported frequency of PEI across the included studies varied widely, though more than two-thirds of included papers reported an incidence of PEI above 65% in patients who underwent pancreatoduodenectomy or distal pancreatectomy. The faecal elastase-1 (FE-1) test was the most frequently used test for diagnosing post-pancreatectomy PEI. Six studies compared the diagnostic accuracy of FE-1 with faecal fat tests or 13 C breath tests, finding no significant differences. Five studies reported on micronutrient deficiencies.

CONCLUSION

The FE-1 test is the most commonly used diagnostic tool for post-pancreatectomy PEI; however, well-designed studies comparing the diagnostic accuracy of various tests for PEI are lacking. Additionally, few studies report on micronutrient deficiencies, variations in anthropometric data or PEI-related patient-reported outcomes. Future studies should aim to establish a gold standard for diagnosis and severity assessment of post-pancreatectomy PEI and provide guidance for tailored pancreatic enzyme replacement therapy.

The role of health economics within health technology assessment: past, present, and future - an Austrian perspective

In many countries, the economics domain forms a routine part of health technology assessments (HTA) next to analyzing the comparative effectiveness and safety of a technology. The method applied most often is economic evaluation, such as cost-effectiveness analysis, which is supposed to support the efficient use of resources. In Austria, economic evaluation has played a negligible role in HTA and reimbursement decisions, even though the country faces the same public healthcare sustainability challenges as others. In this commentary, we argue that while health economics will need to play a more active role in HTA-related decision support to deal with those challenges, current approaches in other countries may have to be broadened to fit the Austrian context. We are outlining four arguments to underpin this perspective: First, economic evaluations (in their current form) are of limited benefit for supporting reimbursement decisions of new high-priced technologies. Second, a broader variety of health economic methods is needed to address the scope of technologies. Third, applying health economic methods requires a reflection on their underlying values. Finally, health economics within HTA needs to go beyond microeconomic analysis of interventions. We are suggesting several alternative methods and approaches, encouraging out-of-the-box thinking and experimenting with methods developed in the academic context but rarely applied in routine HTA. Although some of our topics are unique to Austria, others may equally apply to other healthcare systems. With our thoughts, we aim to stimulate discussions for further developing health economics within HTA in Austria and internationally.

Issues, Challenges and Opportunities for Economic Evaluations of Orphan Drugs in Rare Diseases: An Umbrella Review

BACKGROUND AND OBJECTIVES

There are significant challenges when obtaining clinical and economic evidence for health technology assessments of rare diseases. Many of them have been highlighted in previous systematic reviews but they have not been summarised in a comprehensive manner. For all stakeholders working with rare diseases, it is important to be aware and understand these issues. The objective of this review is to identify the main challenges for the economic evaluation of orphan drugs in rare diseases.

METHODS

An umbrella review of systematic reviews of economic studies concerned with orphan and ultra-orphan drugs was conducted. Studies that were not systematic reviews, or on advanced therapeutic medicinal products, personalised medicines or other interventions that were not considered orphan drugs were excluded. The database searches included publications from 2010 to 2023, and were conducted in MEDLINE, EMBASE and the Cochrane library using filters for systematic reviews, and economic evaluations and models. These filters were combined with search terms for rare diseases and orphan drugs. A hand search supplemented the literature searches. The findings were reported by a compliant Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram.

RESULTS

Two hundred and eighty-two records were identified from the literature searches, of which 64 were duplicates, whereas five reviews were identified from the hand search. A total of 36 reviews were included after screening against inclusion/exclusion criteria, 35 from literature searches and one from hand searching. Of those studies 1, 27 and 8 were low, moderate and high quality, respectively. The reviews highlight the scarcity of evidence for health economic parameters, for example, clinical effectiveness, costs, quality of life and the natural history of disease. Health economic evaluations such as cost-effectiveness and budget-impact analyses were scarce, and generally low-to-moderate quality. The causes were limited health economic parameters, together with publications bias, especially for cost-effectiveness analyses.

CONCLUSIONS

The results highlighted issues around a considerable paucity of evidence for economic evaluations and few cost-effectiveness analyses, supporting the notion that a paucity of evidence makes economic evaluations of rare diseases more challenging compared with more prevalent diseases. Furthermore, we provide recommendations for more sustainable approaches in economic evaluations of rare diseases.

A systematic literature review on the health-related quality of life and economic burden of Fabry disease

BACKGROUND

Fabry disease (FD) is a rare lysosomal storage disease associated with glycolipid accumulation that impacts multiple physiological systems. We conducted a systematic literature review (SLR) to characterize the humanistic (quality of life [QoL]) and economic burden of FD.

METHODS

Searches were conducted in the Embase, MEDLINE®, and MEDLINE® In-Process databases from inception to January 19, 2022. Conference abstracts of specified congresses were manually searched. Additional searches were performed in the Cochrane and ProQuest databases for the humanistic SLR and the National Health Service Economic Evaluations Database for the economic SLR. Studies of patients with FD of any sex, race, and age, and published in the English language were included. There was no restriction on intervention or comparator. For the humanistic SLR, studies that reported utility data, database/registry-based studies, questionnaires/surveys, and cohort studies were included. For the economic SLR, studies reporting economic evaluations or assessing the cost of illness and resource use were included.

RESULTS

Of the 1363 records identified in the humanistic search, 36 studies were included. The most commonly used QoL assessments were the 36-item Short-Form Health Survey (n = 16), EQ-5D questionnaire descriptive system or visual analog scale (n = 9), and the Brief Pain Inventory (n = 8). Reduced QoL was reported in patients with FD compared with healthy populations across multiple domains, including pain, physical functioning, and depressive symptoms. Multiple variables-including sex, age, disease severity, and treatment status-impacted QoL. Of the 711 records identified in the economic burden search, 18 studies were included. FD was associated with high cost and healthcare resource use. Contributors to the cost burden included enzyme replacement therapy, healthcare, and social care. In the seven studies that reported health utility values, lower utility scores were generally associated with more complications (including cardiac, renal, and cerebrovascular morbidities) and with classical disease in males.

CONCLUSION

FD remains associated with a high cost and healthcare resource use burden, and reduced QoL compared with healthy populations. Integrating information from QoL and economic assessments may help to identify interventions that are likely to be of most value to patients with FD.

A review on Gaucher disease: therapeutic potential of β-glucocerebrosidase-targeted mRNA/saRNA approach

Gaucher disease (GD), a rare hereditary lysosomal storage disorder, occurs due to a deficiency in the enzyme β-glucocerebrosidase (GCase). This deficiency leads to the buildup of substrate glucosylceramide (GlcCer) in macrophages, eventually resulting in various complications. Among its three types, GD2 is particularly severe with neurological involvements. Current treatments, such as enzyme replacement therapy (ERT), are not effective for GD2 and GD3 due to their inability to cross the blood-brain barrier (BBB). Other treatment approaches, such as gene or chaperone therapies are still in experimental stages. Additionally, GD treatments are costly and can have certain side effects. The successful use of messenger RNA (mRNA)-based vaccines for COVID-19 in 2020 has sparked interest in nucleic acid-based therapies. Remarkably, mRNA technology also offers a novel approach for protein replacement purposes. Additionally, self-amplifying RNA (saRNA) technology shows promise, potentially producing more protein at lower doses. This review aims to explore the potential of a cost-effective mRNA/saRNA-based approach for GD therapy. The use of GCase-mRNA/saRNA as a protein replacement therapy could offer a new and promising direction for improving the quality of life and extending the lifespan of individuals with GD.

Exploring Pro-Inflammatory Immunological Mediators: Unraveling the Mechanisms of Neuroinflammation in Lysosomal Storage Diseases

Lysosomal storage diseases are a group of rare and ultra-rare genetic disorders caused by defects in specific genes that result in the accumulation of toxic substances in the lysosome. This excess accumulation of such cellular materials stimulates the activation of immune and neurological cells, leading to neuroinflammation and neurodegeneration in the central and peripheral nervous systems. Examples of lysosomal storage diseases include Gaucher, Fabry, Tay–Sachs, Sandhoff, and Wolman diseases. These diseases are characterized by the accumulation of various substrates, such as glucosylceramide, globotriaosylceramide, ganglioside GM2, sphingomyelin, ceramide, and triglycerides, in the affected cells. The resulting pro-inflammatory environment leads to the generation of pro-inflammatory cytokines, chemokines, growth factors, and several components of complement cascades, which contribute to the progressive neurodegeneration seen in these diseases. In this study, we provide an overview of the genetic defects associated with lysosomal storage diseases and their impact on the induction of neuro-immune inflammation. By understanding the underlying mechanisms behind these diseases, we aim to provide new insights into potential biomarkers and therapeutic targets for monitoring and managing the severity of these diseases. In conclusion, lysosomal storage diseases present a complex challenge for patients and clinicians, but this study offers a comprehensive overview of the impact of these diseases on the central and peripheral nervous systems and provides a foundation for further research into potential treatments.

Evaluation of dried-blood spots and a hematocrit-independent procedure in lysosomal diseases screening using multiplexed tandem mass spectrometry assays

BACKGROUND

Dried blood spots (DBS) are widely used as a non-invasive sampling method, especially in newborn screening (NBS). Despite its numerous advantages, conventional DBS might be limited by the hematocrit effect when analyzing a punch, depending on its position in the blood spot. This effect could be avoided using hematocrit-independent sampling devices such as the hemaPEN®. This device collects blood through integrated microcapillaries, and a fixed blood volume is deposited on a pre-punched paper disc. NBS programs are increasingly poised to include lysosomal disorders, given the availability of treatments that improve clinical outcomes if detected early. In this study, the effect of hematocrit and punch position in the DBS on the assay of 6 lysosomal enzymes was evaluated on 3 mm discs pre-punched in hemaPEN® devices compared to 3 mm punches from the PerkinElmer 226 DBS.

METHODS

The enzyme activities were measured by multiplexed tandem mass spectrometry coupled to ultra-high performance liquid chromatography. Three hematocrit levels (23%, 35%, and 50%) and punching positions (center, intermediary, and border) were tested. Three replicates have been performed for each condition. A multivariate approach has been used along with a univariate method to assess the effect of the experimental design on each enzyme activity.

RESULTS

Hematocrit, punch position, and whole blood sampling method do not affect the assessment of enzyme activity using the NeoLSD® assay.

CONCLUSION

The results obtained from conventional DBS and the volumetric device HemaPEN® are comparable. These results underline the reliability of DBS for this test.

Targeting the central nervous system in lysosomal storage diseases: Strategies to deliver therapeutics across the blood-brain barrier

Lysosomal storage diseases (LSDs) are multisystem inherited metabolic disorders caused by dysfunctional lysosomal activity, resulting in the accumulation of undegraded macromolecules in a variety of organs/tissues, including the central nervous system (CNS). Treatments include enzyme replacement therapy, stem/progenitor cell transplantation, and in vivo gene therapy. However, these treatments are not fully effective in treating the CNS as neither enzymes, stem cells, nor viral vectors efficiently cross the blood-brain barrier. Here, we review the latest advancements in improving delivery of different therapeutic agents to the CNS and comment upon outstanding questions in the field of neurological LSDs.