The cost effectiveness of dry powder antibiotics for the treatment of Pseudomonas aeruginosa in patients with cystic fibrosis

Are We Capturing the Socioeconomic Burden of Rare Genetic Disease? A Scoping Review of Economic Evaluations and Cost-of-Illness Studies

BACKGROUND AND OBJECTIVES

Rare diseases have a significant impact on patients, families, the health system, and society. Measuring the socioeconomic burden is crucial to valuing interventions for rare diseases. Healthcare system costs are significant, but so are costs to other government sectors, patients, families, and society. To understand the breadth of costs captured in rare disease studies, we examined the cost categories and elements of socioeconomic burden captured in published studies.

METHODS

A scoping review was conducted using five electronic databases to identify English language economic evaluations and cost-of-illness studies of interventions for rare diseases (2011-21). We mapped costs using a previously developed evidence-informed framework of socioeconomic burden costs for rare disease.

RESULTS

Of 4890 studies identified, 48 economic evaluations and 22 cost-of-illness studies were included. While 18/22 cost-of-illness studies utilized a societal perspective, only 7/48 economic evaluations incorporated societal costs. Most reported cost categories related to medical costs, with medication and hospitalizations being the most common elements for both study designs. Costs borne by patients, families, and society were reported less among economic evaluations than cost-of-illness studies. These included: productivity (10% vs 77%), travel/accommodation (6% vs 68%), government benefits (4% vs 18%), and family impacts (0% vs 50%).

CONCLUSIONS

Contrary to cost-of-illness analyses, most of the included economic evaluations did not account for the hidden burden of rare diseases, that is, costs borne by patients, families, and societies. Including these types of costs in future studies would provide a more comprehensive picture of the burden of disease, providing empirical data to inform how we value and make decisions regarding rare disease interventions, health policy, and resource allocation.

Cost-effectiveness analysis of genetic tools to predict treatment response in patients with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulator therapies show variable efficacy for patients with CF. Patient-derived predictive tools may identify individuals likely to respond to CFTRs, but are not in routine use. We aimed to determine the cost-utility of predictive tool-guided treatment with CFTRs as add-on to standard of care (SoC) for individuals with CF.

METHODS

This economic evaluation compared two strategies using an individual level simulation: (i) Treat All, where all patients received CFTRs plus SoC and (ii) Test→Treat, where patients who tested positive on predictive tools received CFTRs plus SoC and those who tested negative received SoC only. We simulated 50,000 individuals over their lifetime, and estimated costs (2020 CAD) per quality-adjusted life year (QALY) from the healthcare payer's perspective, discounted at 1.5% annually. The model was populated using Canadian CF registry data and published literature. Probabilistic and deterministic sensitivity were conducted.

RESULTS

The Treat All and Test→Treat and strategies yielded 22.41 and 21.36 QALYs, and cost $4.21 M and $3.15 M respectively. Results of probabilistic sensitivity analysis showed that Test→Treat was highly cost-effective compared to Treat All in 100% of simulations at cost-effectiveness thresholds as high as $500,000 per QALY. Test→Treat may save between $931 K to $1.1 M per QALY lost, depending on sensitivity and specificity of predictive tools.

CONCLUSION

The use of predictive tools could optimize the health benefits of CFTR modulators while reducing costs. Our findings support the use of pre-treatment predictive testing and may help inform coverage and reimbursement policies for individuals with CF.

Economic evaluations of radioembolization with yttrium-90 microspheres in liver metastases of colorectal cancer: a systematic review

BACKGROUND

Transarterial radioembolization with yttrium-90 (Y-90 TARE) microspheres therapy has demonstrated positive clinical benefits for the treatment of liver metastases from colorectal cancer (lmCRC). This study aims to conduct a systematic review of the available economic evaluations of Y-90 TARE for lmCRC.

METHODS

English and Spanish publications were identified from PubMed, Embase, Cochrane, MEDES health technology assessment agencies, and scientific congress databases published up to May 2021. The inclusion criteria considered only economic evaluations; thus, other types of studies were excluded. Purchasing-power-parity exchange rates for the year 2020 ($US PPP) were applied for cost harmonisation.

RESULTS

From 423 records screened, seven economic evaluations (2 cost-analyses [CA] and 5 cost-utility-analyses [CUA]) were included (6 European and 1 USA). All included studies (n = 7) were evaluated from a payer and the social perspective (n = 1). Included studies evaluated patients with unresectable liver-predominant metastases of CRC, refractory to chemotherapy (n = 6), or chemotherapy-naïve (n = 1). Y-90 TARE was compared to best supportive care (BSC) (n = 4), an association of folinic acid, fluorouracil and oxaliplatin (FOLFOX) (n = 1), and hepatic artery infusion (HAI) (n = 2). Y-90 TARE increased life-years gained (LYG) versus BSC (1.12 and 1.35 LYG) and versus HAI (0.37 LYG). Y-90 TARE increased the quality-adjusted-life-year (QALY) versus BSC (0.81 and 0.83 QALY) and versus HAI (0.35 QALY). When considering a lifetime horizon, Y-90 TARE reported incremental cost compared to BSC (range 19,225 to 25,320 $US PPP) and versus HAI (14,307 $US PPP). Y-90 TARE reported incremental cost-utility ratios (ICURs) between 23,875 $US PPP/QALY to 31,185 $US PPP/QALY. The probability of Y-90 TARE being cost-effective at £ 30,000/QALY threshold was between 56% and 57%.

CONCLUSIONS

Our review highlights that Y-90 TARE could be a cost-effective therapy either as a monotherapy or when combined with systemic therapy for treating ImCRC. However, despite the current clinical evidence on Y-90 TARE in the treatment of ImCRC, the global economic evaluation reported for Y-90 TARE in ImCRC is limited (n = 7), therefore, we recommend future economic evaluations on Y-90 TARE versus alternative options in treating ImCRC from the societal perspective.

Dry Powder Inhalation for Lung Delivery in Cystic Fibrosis

Pulmonary drug delivery has long been used for local and systemic administration of different medications used in acute and chronic respiratory diseases. Certain lung diseases, such as cystic fibrosis, rely heavily on chronic treatments, including targeted lung delivery. Pulmonary drug delivery possesses various physiological advantages compared to other delivery methods and is also convenient for the patient to use. However, the formulation of dry powder for pulmonary delivery proves challenging due to aerodynamic restrictions and the lower tolerance of the lung. The aim of this review is to provide an overview of the respiratory tract structure in patients with cystic fibrosis, including during acute and chronic lung infections and exacerbations. Furthermore, this review discusses the advantages of targeted lung delivery, including the physicochemical properties of dry powder and factors affecting clinical efficacy. Current inhalable drug treatments and drugs currently under development will also be discussed.

The Impact of Resistant Bacterial Pathogens including Pseudomonas aeruginosa and Burkholderia on Lung Transplant Outcomes

Pseudomonas and Burkholderia are gram-negative organisms that achieve colonization within the lungs of patients with cystic fibrosis, and are associated with accelerated pulmonary function decline. Multidrug resistance is a hallmark of these organisms, which makes eradication efforts difficult. Furthermore, the literature has outlined increased morbidity and mortality for lung transplant (LTx) recipients infected with these bacterial genera. Indeed, many treatment centers have considered Burkholderia cepacia infection an absolute contraindication to LTx. Ongoing research has delineated different species within the B. cepacia complex (BCC), with significantly varied morbidity and survival profiles. This review considers the current evidence for LTx outcomes between the different subspecies encompassed within these genera as well as prophylactic and management options. The availability of meta-genomic tools will make differentiation between species within these groups easier in the future, and will allow more evidence-based decisions to be made regarding suitability of candidates colonized with these resistant bacteria for LTx. This review suggests that based on the current evidence, not all species of BCC should be considered contraindications to LTx, going forward.

Cost-Effectiveness of Ivacaftor Therapy for Treatment of Cystic Fibrosis Patients With the G551D Gating Mutation

OBJECTIVES

Cystic fibrosis (CF) is a rare genetic disease with no cure. Until recently, treatment has targeted symptoms of the disease and not the disease-causing genetic defect. Ivacaftor is included in a new class of breakthrough drugs targeting the genetic defects of CF. We sought to estimate the long-term cost-effectiveness of ivacaftor from a US payer perspective.

METHODS

We developed an individual-level microsimulation model that followed a cohort of heterogeneous US CF patients over a lifetime. The primary outcome of interest was quality-adjusted life years (QALYs). We also compared unadjusted life years, count of acute pulmonary exacerbations, and count of lung transplants over a lifetime between patients treated with ivacaftor plus best supportive care and patients treated with best supportive care alone. We conducted one-way and probabilistic sensitivity analyses to test the impact of various model inputs and uncertainties.

RESULTS

We found a substantial increase in QALYs, life years, and treatment costs over a lifetime for patients treated with ivacaftor plus best supportive care versus best supportive care alone. Discounted results for ivacaftor were 22.92 QALYs and $8 797 840 in total lifetime costs compared to 16.12 QALYs and $2 336 366 lifetime costs for best supportive care alone. The incremental cost-effectiveness ratios (ICERs) were $950 217 per QALY. Results from the probabilistic sensitivity analysis indicated a 0% chance that ivacaftor was cost-effective at a willingness-to-pay (WTP) threshold of $500 000 per QALY.

CONCLUSIONS

Treatment with ivacaftor plus best supportive care versus best supportive care alone is not cost-effective at or near commonly accepted WTP thresholds.

More Unnecessary Imaginary Worlds - Part 3: Cystic Fibrosis and the Institute for Clinical and Economic Review's Draft Evidence Report

On 20 February 2020, the Institute for Clinical and Economic Review (ICER) released its draft evidence report to establish the value of innovative therapies in the treatment of cystic fibrosis. Following its usual practice, ICER contracted with an outside group to construct a value assessment framework, in this case a microsimulation model, to generate value claims. The primary outcomes for value claims were incremental cost-per-QALY simulations for four target cystic fibrosis populations. The value assessment, in common with the same model applied earlier by ICER in cystic fibrosis, recommended substantial price discounts based on arbitrary threshold cost-per-QALY values. Unfortunately, the entire exercise, as detailed in previous commentaries in INNOVATIONS in Pharmacy is essentially a waste of time. Not only is the reference case model presented by ICER only one of a multiverse of other models, all driven by a selective application of model structure and assumptions, but the fact that the utilities that are applied to hypothetical time spent in different disease stages to modeled QALYs and lifetime cost-per-QALY claims fail to meet fundamental measurement axioms: they are ordinal manifest scores. Applied to target cystic fibrosis target patient groups, the modeled claims are meaningless. From the manufacturer's perspective, in this case Vertex Pharmaceuticals who have developed all the cystic fibrosis therapies 'modeled' by the ICER contractor, their response to ICER claims should be to reject them out of hand; the constructs are imaginary and the outcome claims nonsense.

Health economic modelling in Cystic Fibrosis: A systematic review

INTRODUCTION

Cystic Fibrosis (CF) is a heritable chronic condition. Due to the genetic and progressive nature of CF, a number of interventions are available for the condition. In the United Kingdom (U.K.) average annual cost of CF treatment is between €49,000 to €76,000 (2012) per patient [1]. A review of health economic modelling studies is warranted to provide decision makers and researchers with an in depth understanding of modelling practices in CF and guidance for future research.

METHODS

Online searches were performed in the 5 databases, studies were included if they were: a) Model based economic evaluation for management of Cystic Fibrosis. Articles were restricted to English language only, but no restriction was applied on publication year.

RESULTS

Nine studies were reviewed, most were Markov cohort models. Models evaluated pharmaceutical interventions and drug adherence. Modelling structure was consistent across most articles and a range of sources were used to populate the models. Cost and utility data were based on different sources and elicitation methods respectively. The majority of models failed to incorporate significant health events which impact both cost and disease progression.

CONCLUSION

In our review we observed a lack of, application of European Medicines Agency (EMA) guidelines for clinical trial endpoints, model structure justifications and lastly, health-related quality of life derived utility information around important clinical events. Future work around conceptual modelling of CF progression, utility valuation of significant health events and meeting EMA guidelines for trial reporting is encouraged.

Cost-effectiveness analysis of lumacaftor and ivacaftor combination for the treatment of patients with cystic fibrosis in the United States

Background

Lumacaftor/ivacaftor was approved by the Food and Drug Administration (FDA) as a combination treatment for Cystic Fibrosis (CF) patients who are homozygous for the F508del mutation. The objective of this study was to assess the cost-effectiveness of lumacaftor/ivacaftor combination for the treatment of CF homozygous for F508del CF Transmembrane Conductance Regulator (CFTR) mutation.

Methods

A Markov-state transition model following a cohort of 12 year-old CF patients homozygous for F508del CFTR mutation in the United States (US) over two, four, six, eight and ten years from a payer’s perspective was developed using TreeAge Pro 2016. Markov states included: mild (percentage of predicted forced expiratory volume in 1 s or FEV1 > 70%), moderate (FEV1 40–70%), severe (FEV1 < 40%) disease, post-transplant, and death. Pulmonary exacerbation and lung transplant were included as transition states. All the input parameters were estimated from the literature. A 1-year cycle length and 3% discount rate were applied. To assess uncertainty in long-term treatment effects, several scenarios were modelled: 100% long-term effectiveness (base-case), defined as improvement in FEV1 in the first year followed by no annual FEV1 decline and a constant reduction in pulmonary exacerbations throughout, 75%, 50%, 25% and 0% (worst case) long-term effectiveness, where treatment effects were intermediate from the second year of treatment until the end of the time horizon. Other scenarios included changing the starting age of the cohort to 6 and 25 years. Primary outcome included incremental cost-effectiveness ratio (ICER) in terms of cost per quality adjusted life year (QALY) gained. One-way and probabilistic sensitivity analyses were performed to determine uncertainty.

Results

Under the base-case, Lumacaftor/ivacaftor resulted in higher QALYs (7.29 vs 6.84) but at a very high cost ($1,778,920.88) compared to usual care ($116,155.76) over a 10-year period. The ICER for base-case and worst-case scenarios were $3,655,352 / QALY, and $8,480,265/QALY gained, respectively. In the base-case, lumacaftor/ivacaftor was cost-effective at a threshold of $150,000/QALY-gained when annual drug costs were lower than $4153. The results were not substantially affected by the sensitivity analyses.

Conclusions

The intervention produces large QALY gains but at an extremely high cost, resulting in an ICER that would not typically be covered by any insurer. Lumacaftor/ivacaftor’s status as an orphan drug complicates coverage decisions.

Correspondence between symptoms and preference-based health status measures in the STOP study

BACKGROUND

Pulmonary exacerbations (PEx) in cystic fibrosis (CF) patients decrease lung function, increase symptoms and reduce health-related quality of life (HRQoL). We evaluated associations between 8 symptom-based questions from the Cystic Fibrosis Respiratory Symptom Diary - Chronic Respiratory Infection Symptom Score (CFRSD-CRISS) and the 5-level EuroQOL-5 Dimensions (EQ-5D-5 L) summary score and hypothesized the CFRSD-CRISS would be well-correlated with quality-of-life measures among CF patients with PEx.

METHODS

CF patients who had CFRSD-CRISS and EQ-5D-5L measurements on the day of the initial PEx, 7 days later, and at the end of intravenous antibiotic treatment were included. We examined age-stratified (<18 versus ≥18 years old) characteristics, including the percent predicted of forced expiratory volume in 1 s (ppFEV1), CFRSD-CRISS measurements, and domains of the EQ-5D. We also calculated age-stratified Pearson correlation coefficients between the EQ-5D-5L and CFRSD-CRISS items at each of the 3 time points.

RESULTS

A total of 169 patients were analyzed. Patients reported having problems performing usual activities and with pain/discomfort on the first day of the PEx and these measures improved by the end of treatment. PpFEV1 improved in both age categories by the end of PEx treatment but was not associated with the change in summary EQ-5D-5 L over the time of PEx treatment (r-squared = 0.029). Correlations were weak (generally <0.4) between the elements of the EQ-5D-5 L versus the CFRSD-CRISS.

CONCLUSIONS

Value assessment of treatments for CF PEx will require the collection of preference-weighted measures rather than only the symptom-based questions of the CFRSD-CRISS.

An Early Health Economic Analysis of the Potential Cost Effectiveness of an Adherence Intervention to Improve Outcomes for Patients with Cystic Fibrosis

BACKGROUND

Cystic fibrosis (CF) negatively impacts upon health-related quality of life and survival. Adherence to nebulised treatments is low; improving adherence is hypothesised to reduce rates of exacerbation requiring intravenous antibiotics and lung function decline.

OBJECTIVE

A state transition model was developed to assess the cost effectiveness of an intervention aimed at increasing patient adherence to nebulised and inhaled antibiotics compared with current CF care, in advance of the forthcoming CFHealthHub randomised controlled trial (RCT).

METHODS

The model estimated the costs and health outcomes for each option from the perspective of the UK National Health Service and Personal Social Services over a lifetime horizon. Health gains were valued in terms of quality-adjusted life-years (QALYs) gained. Forced expiratory volume in 1 second (FEV₁) trajectories were predicted over three lung function strata: (1) FEV₁ ≥70%, (2) FEV₁ 40-69% and (3) FEV₁ <40%. Additional states were included to represent 'post-lung transplantation' and 'dead'. The model was populated using CF Registry data, literature and expert opinion. Costs were presented at 2016 values. Uncertainty was assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

If effective, the adherence intervention is expected to produce an additional 0.19 QALYs and cost savings of £64,078 per patient. Across all analyses, the intervention dominated current care. Over a 5-year period, the intervention is expected to generate cost savings of £49.5 million for the estimated 2979 patients with CF with Pseudomonas aeruginosa currently aged ≥16 years in the UK. If applied to a broader population of adult patients with CF receiving any nebulised therapy, the expected savings could be considerably greater.

CONCLUSIONS

If effective, the adherence intervention is expected to produce additional health gains at a lower cost than current CF care. However, the economic analysis should be revisited upon completion of the full RCT. More generally, the analysis suggests that considerable gains could be accrued through the implementation of adherence interventions that shift care from expensive hospital-based rescue to community-based prevention.

Dry powder inhalers in cystic fibrosis: same old drugs but different benefits?

PURPOSE OF REVIEW

Newer 'innovative' formulations of antibiotics for Pseudomonas aeruginosa lung infection in patients with cystic fibrosis include colistimethate sodium and tobramycin in the form of dry powders for inhalation (DPIs). Whilst these DPIs are anticipated to improve patient adherence because of increased convenience and ease of administration, questions remain concerning whether they are as clinically effective, safe and cost-effective as nebulized antibiotics.

RECENT FINDINGS

This review describes the recent findings of a health technology assessment of the clinical effectiveness and cost-effectiveness of colistimethate sodium and tobramycin DPIs with regard to how innovative treatments may be judged to be incrementally better than existing treatments. The original assessment was undertaken to inform the National Institute for Health and Care Excellence's Technology Appraisal Programme to inform national clinical guidance on the use of these new treatments in the National Health Service.

SUMMARY

Three trials were included in the systematic review. Issues surrounding the clinical effectiveness and cost-effectiveness of colistimethate sodium DPI and tobramycin DPI are discussed in light of the considerable uncertainties associated with the available evidence.