Assessing the cost-effectiveness of mepolizumab as add-on therapy to standard of care for severe eosinophilic asthma in Singapore.

OBJECTIVE: To evaluate the cost-effectiveness of mepolizumab added to standard of care (SOC) compared with SOC alone among patients with severe uncontrolled eosinophilic asthma in the Singapore setting. METHODS: A Markov model with three health states (asthma on mepolizumab and SOC, asthma on SOC alone, and death) was developed from a healthcare system perspective over a lifetime horizon. During each 4-week cycle, patients in the non-death health states could experience asthma exacerbations requiring oral corticosteroid burst, emergency department visit, or hospitalization. Asthma-related mortality following an exacerbation or all-cause mortality could also occur at each cycle. The model was populated using local costs while utilities were derived from international literature. Transition probabilities were obtained from a mixture of Singapore-specific and internationally published data. RESULTS: The base-case analysis comparing mepolizumab plus SOC with SOC alone resulted in an incremental cost-effectiveness ratio (ICER) of SGD335 486 (USD238 195) per quality-adjusted life-year (QALY) gained. Sensitivity analysis demonstrated that the ICER was most sensitive to the price of mepolizumab, followed by the proportion of exacerbations which required hospital intensive care. Despite restricting mepolizumab use to patients with a higher baseline exacerbation rate (3 in the past year) in a scenario analysis, the ICER remained high at SGD238 876 (USD 169 602) per QALY gained. CONCLUSION: At its current price, mepolizumab is not considered a cost-effective use of healthcare resources in Singapore. Substantial price reductions for mepolizumab are required to improve its cost-effectiveness to an acceptable range. These results will be useful to inform national funding decisions.

Cost-effectiveness of transcatheter aortic valve implantation in patients with severe symptomatic aortic stenosis of intermediate surgical risk in Singapore.

OBJECTIVE: The objective was to assess the cost-effectiveness of transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis with intermediate surgical risk in Singapore. METHODS: A de novo Markov model with three health states - stroke with long-term sequelae, no stroke, and death - was developed and simulated using Monte Carlo simulations with 10,000 iterations over a five-year time horizon from the Singapore healthcare system perspective. A 3% annual discount rate for costs and outcomes and monthly cycle lengths were used. By applying the longest available published clinical evidence, simulated patients received either TAVI or surgical aortic valve replacement (SAVR) and were at risk of adverse events (AEs) such as moderate-to-severe paravalvular aortic regurgitation (PAR). RESULTS: When five-year PARTNER 2A data was applied, base-case analyses showed that the incremental cost-effectiveness ratio (ICER) for TAVI compared to SAVR was US$315,760 per quality-adjusted life year (QALY) gained. The high ICER was due to high incremental implantation and procedure costs of TAVI compared to SAVR, and marginal improvement of 0.10 QALYs as simulated mortality of TAVI exceeded SAVR at 3.75 years post-implantation. One-way sensitivity analysis showed that the ICERs were most sensitive to cost of PAR, utility values of SAVR patients, and cost of TAVI and SAVR implants and procedures. When disutilities for AEs were additionally applied, the ICER decreased to US$300,070 per QALY gained. TAVI was dominated by SAVR when the time horizon increased to 20 years. Clinical outcomes projected from one-year PARTNER S3i data further reduced the ICER to US$86,337 per QALY gained for TAVI, assuming early all-cause mortality benefits from TAVI continued to persist. This assumption was undermined when longer term data showed that TAVI's early mortality benefits diminished at five years. LIMITATIONS AND CONCLUSION: TAVI is unlikely to be cost-effective in intermediate surgical-risk patients compared to SAVR in Singapore.

Isogenic Human-Induced Pluripotent Stem-Cell-Derived Cardiomyocytes Reveal Activation of Wnt Signaling Pathways Underlying Intrinsic Cardiac Abnormalities in Rett Syndrome.

Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by MeCP2 mutations. Nonetheless, the pathophysiological roles of MeCP2 mutations in the etiology of intrinsic cardiac abnormality and sudden death remain unclear. In this study, we performed a detailed functional studies (calcium and electrophysiological analysis) and RNA-sequencing-based transcriptome analysis of a pair of isogenic RTT female patient-specific induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs) that expressed either MeCP2wildtype or MeCP2mutant allele and iPSC-CMs from a non-affected female control. The observations were further confirmed by additional experiments, including Wnt signaling inhibitor treatment, siRNA-based gene silencing, and ion channel blockade. Compared with MeCP2wildtype and control iPSC-CMs, MeCP2mutant iPSC-CMs exhibited prolonged action potential and increased frequency of spontaneous early after polarization. RNA sequencing analysis revealed up-regulation of various Wnt family genes in MeCP2mutant iPSC-CMs. Treatment of MeCP2mutant iPSC-CMs with a Wnt inhibitor XAV939 significantly decreased the ß-catenin protein level and CACN1AC expression and ameliorated their abnormal electrophysiological properties. In summary, our data provide novel insight into the contribution of activation of the Wnt/ß-catenin signaling cascade to the cardiac abnormalities associated with MeCP2 mutations in RTT.

Cost-effectiveness of MRI targeted biopsy strategies for diagnosing prostate cancer in Singapore.

BACKGROUND: To evaluate the cost-effectiveness of six diagnostic strategies involving magnetic resonance imaging (MRI) targeted biopsy for diagnosing prostate cancer in initial and repeat biopsy settings from the Singapore healthcare system perspective. METHODS: A combined decision tree and Markov model was developed. The starting model population was men with mean age of 65 years referred for a first prostate biopsy due to clinical suspicion of prostate cancer. The six diagnostic strategies were selected for their relevance to local clinical practice. They comprised MRI targeted biopsy following a positive pre-biopsy multiparametric MRI (mpMRI) [Prostate Imaging - Reporting and Data System (PI-RADS) score ≥ 3], systematic biopsy, or saturation biopsy employed in different testing combinations and sequences. Deterministic base case analyses with sensitivity analyses were performed using costs from the healthcare system perspective and quality-adjusted life years (QALY) gained as the outcome measure to yield incremental cost-effectiveness ratios (ICERs). RESULTS: Deterministic base case analyses showed that Strategy 1 (MRI targeted biopsy alone), Strategy 2 (MRI targeted biopsy ➔ systematic biopsy), and Strategy 4 (MRI targeted biopsy ➔ systematic biopsy ➔ saturation biopsy) were cost-effective options at a willingness-to-pay (WTP) threshold of US$20,000, with ICERs ranging from US$18,975 to US$19,458. Strategies involving MRI targeted biopsy in the repeat biopsy setting were dominated. Sensitivity analyses found the ICERs were affected mostly by changes to the annual discounting rate and prevalence of prostate cancer in men referred for first biopsy, ranging between US$15,755 to US$23,022. Probabilistic sensitivity analyses confirmed Strategy 1 to be the least costly, and Strategies 2 and 4 being the preferred strategies when WTP thresholds were US$20,000 and US$30,000, respectively. LIMITATIONS AND CONCLUSIONS: This study found MRI targeted biopsy to be cost-effective in diagnosing prostate cancer in the biopsy-naïve setting in Singapore.

A review of implementation frameworks to operationalize health technology assessment recommendations for medical technologies in the Singapore setting.

BACKGROUND: Methodologies of health technology assessment (HTA) for medical technologies are well established; yet, operational frameworks that enable appropriate uptake of HTA recommendations into routine clinical practice are lacking. This review aims to identify the key themes needed to guide the planning and implementation of HTA subsidy decisions for medical technologies such as diagnostics, medical devices, and services and to monitor their impact on a complex multipayer healthcare system like Singapore. METHODS: A literature search of implementation frameworks was conducted up to 20 December 2020 and was documented in a flow diagram. A thematic analysis of the evidence base was performed using the Braun and Clark approach to identify key themes, from which an implementation framework suitable for Singapore's healthcare system could be developed. RESULTS: The searches yielded forty-four articles for review, from which twenty themes were identified. The top ten themes constituted the key themes of implementation essential for local adaptation and were categorized into five domains: implementation strategy, organizational support, stakeholder engagement, information dissemination, and implementation outcomes and evaluation. These domains provide operational guidance to methodically identify gaps to facilitate sustainable implementation of HTA-informed medical technology subsidy decisions. CONCLUSION: A robust and adaptable implementation of HTA-informed subsidy decisions is crucial to optimize its intended impact of improving patient outcomes per dollar spent. The key themes of an implementation framework should capture the important aspects of organizational feasibility to ensure successful adoption in a complex multipayer healthcare system like Singapore.

Application of Patient-Specific iPSCs for Modelling and Treatment of X-Linked Cardiomyopathies.

Inherited cardiomyopathies are among the major causes of heart failure and associated with significant mortality and morbidity. Currently, over 70 genes have been linked to the etiology of various forms of cardiomyopathy, some of which are X-linked. Due to the lack of appropriate cell and animal models, it has been difficult to model these X-linked cardiomyopathies. With the advancement of induced pluripotent stem cell (iPSC) technology, the ability to generate iPSC lines from patients with X-linked cardiomyopathy has facilitated in vitro modelling and drug testing for the condition. Nonetheless, due to the mosaicism of the X-chromosome inactivation, disease phenotypes of X-linked cardiomyopathy in heterozygous females are also usually more heterogeneous, with a broad spectrum of presentation. Recent advancements in iPSC procedures have enabled the isolation of cells with different lyonisation to generate isogenic disease and control cell lines. In this review, we will summarise the current strategies and examples of using an iPSC-based model to study different types of X-linked cardiomyopathy. The potential application of isogenic iPSC lines derived from a female patient with heterozygous Danon disease and drug screening will be demonstrated by our preliminary data. The limitations of an iPSC-derived cardiomyocyte-based platform will also be addressed.

Cost-effectiveness analysis of atezolizumab in advanced triple-negative breast cancer.

BACKGROUND: The IMpassion130 trial demonstrated that adding atezolizumab to nanoparticle albumin-bound (nab)-paclitaxel improved the survival of patients with untreated, advanced, programmed death ligand 1 (PDL1)-positive triple-negative breast cancer (TNBC). In view of the high cost of immunotherapy, it is important to examine its value with respect to both benefits and costs. In this study, the cost-effectiveness of atezolizumab/nab-paclitaxel combination therapy relative to nab-paclitaxel monotherapy was evaluated for the first-line treatment of advanced, PDL1-positive TNBC, from a healthcare system perspective. METHODS: A three-state partitioned-survival model was developed to compare the clinical and economic outcomes of treatment with atezolizumab/nab-paclitaxel combination therapy with nab-paclitaxel monotherapy in patients with advanced TNBC. Clinical data were obtained from the IMpassion130 trial and extrapolated to 5 years. Health state utilities were retrieved from the literature, while direct costs (in Singapore dollars, S$) were sourced from public healthcare institutions in Singapore. The primary outcomes of the model were life years (LYs), quality-adjusted LYs (QALYs), costs and incremental cost-effectiveness ratios (ICERs). One-way and probabilistic sensitivity analyses and scenario analyses were conducted to explore the impact of specific assumptions and uncertainties. RESULTS: Adding atezolizumab to nab-paclitaxel resulted in an additional 0.361 QALYs (0.636 LYs) at an ICER of S$324,550 per QALY gained. The ICER remained high at S$67,092 per QALY even when atezolizumab was priced zero. One-way sensitivity analysis showed that the ICER was most sensitive to variations in the cost of atezolizumab and the time horizon. Scenario analyses confirmed that the ICERs remained high even under extremely favourable assumptions. CONCLUSIONS: Given the exceedingly high ICER, adding atezolizumab to nab-paclitaxel was unlikely to represent good value for money for the treatment of advanced PDL1-positive TNBC. Our findings will be useful in informing funding policy decisions alongside other considerations such as comparative effectiveness, unmet need and budget impact.

Towards greater impact in health technology assessment: horizon scanning for new and emerging technologies in Singapore.

OBJECTIVES: To alert policy makers early about emerging health technologies that could significantly impact the healthcare system at the clinical, financial and organizational levels, the Agency for Care Effectiveness (ACE) in Singapore established a horizon scanning system (HSS) in 2019. This paper describes the development of the ACE HSS and showcases its application with cell and gene therapy products as the first example. METHODS: A literature review of existing HSS methods, including the processes of the EuroScan International Network and other overseas horizon scanning agencies, was done to inform the development of our horizon scanning framework. The framework was first applied to the new and emerging cell and gene therapies. RESULTS: Identification sources, filtration and prioritization criteria, and horizon scanning outputs for the HSS were developed in alignment to international best practices, with recommendations for technology uptake represented by a traffic light system. For the first horizon scanning exercise on cell and gene therapies, forty therapies passed the filtration step, of which eight were prioritized for further assessment. The few early reports developed were used to inform and prepare the healthcare system for their potential introduction, particularly in terms of the need to develop health and funding policies. CONCLUSIONS: Early assessment of prioritized topics has provided support for strategic efforts within the Ministry of Health. Given that ACE's horizon scanning program is still in its infancy, the framework will continue to evolve to ensure relevance to our stakeholders so that it remains fit for purpose for our healthcare system.

Cost-Effectiveness Analysis of Sunitinib versus Interferon-Alfa for First-Line Treatment of Advanced and/or Metastatic Renal Cell Carcinoma in Singapore.

OBJECTIVES: This study was conducted to evaluate the cost-effectiveness of sunitinib versus interferon-alfa for the treatment of advanced and/or metastatic renal cell carcinoma (RCC) in Singapore. METHODS: A partitioned survival model with three health states (progression-free, progressive disease, and death) was developed from a healthcare payer perspective over a 10-year time horizon. Survival curves from the pivotal trial of sunitinib versus interferon-alfa were extrapolated beyond the trial period to estimate the underlying progression-free survival and overall survival parametric distributions. Health state utilities were derived from the literature and direct costs were sourced from local public healthcare institutions. The sunitinib dose in the model reflected local prescribing practices whereby a combination of 50 mg (28 percent) and 37.5 mg (72 percent) strengths are used. RESULTS: The base-case analysis comparing sunitinib versus interferon-alfa resulted in an incremental cost effectiveness ratio (ICER) of SGD191,061 (USD139,757) per quality-adjusted life-year gained. Sensitivity analysis demonstrated that the ICER was most sensitive to variations in the utility value assumed for the progression-free health state and the price of sunitinib. CONCLUSIONS: In the absence of any price reduction, sunitinib had an exceedingly high ICER and was not considered a cost-effective use of healthcare resources in Singapore's context for the first-line treatment of advanced RCC. The findings from our evaluation will be useful to inform local healthcare decision making and resource allocations for tyrosine kinase inhibitors when appraised alongside comparative clinical effectiveness data and payer affordability considerations.

Cost effectiveness analysis of afatinib versus pemetrexed-cisplatin for first-line treatment of locally advanced or metastatic EGFR mutation positive non-small-cell lung cancer from the Singapore healthcare payer's perspective.

BACKGROUND: Non-small-cell lung cancer (NSCLC) accounts for 85% of all lung cancers and is associated with a poor prognosis. Afatinib is an irreversible ErbB family blocker recommended in clinical guidelines as a first-line treatment for NSCLC which harbours an epidermal growth factor receptor (EGFR) mutation. The objective of this study was to evaluate the cost-effectiveness of afatinib versus pemetrexed-cisplatin for first-line treatment of locally advanced or metastatic EGFR mutation positive NSCLC in Singapore. METHODS: A partitioned survival model with three health states (progression-free, progressive disease and death) was developed from a healthcare payer perspective. Survival curves from the LUX-Lung 3 trial (afatinib versus pemetrexed-cisplatin chemotherapy) were extrapolated beyond the trial period to estimate the underlying progression-free survival and overall survival parametric distributions. Rates of adverse reactions were also estimated from LUX-Lung 3 while health utilities from overseas were derived from the literature in the absence of local estimates. Direct costs were sourced from public healthcare institutions in Singapore. Incremental cost-effectiveness ratios (ICERs) were calculated over a 5 year time horizon. Deterministic and probabilistic sensitivity analyses and additional scenario analyses were conducted to explore the impact of uncertainties and assumptions on the cost-effectiveness results. RESULTS: In the base-case analysis, the ICER for afatinib versus pemetrexed-cisplatin was SG$137,648 per quality-adjusted life year (QALY) gained and SG$109,172 per life-year gained. One-way sensitivity analysis showed the ICER was most sensitive to variations in the utility values, the cost of afatinib and time horizon. Scenario analyses showed that even reducing the cost of afatinib by 50% led to a high ICER which was unlikely to represent a cost-effective use of healthcare resources. CONCLUSIONS: Compared with pemetrexed-cisplatin, afatinib is not cost-effective as a first-line treatment for advanced EGFR mutation-positive NSCLC in Singapore. The findings from our study will be useful to inform local healthcare decision-making and resource allocations for NSCLC treatments, together with other considerations such as clinical effectiveness, safety and affordability of TKIs.

Amelioration of X-Linked Related Autophagy Failure in Danon Disease With DNA Methylation Inhibitor.

BACKGROUND: Danon disease is an X-linked disorder that leads to fatal cardiomyopathy caused by a deficiency in lysosome-associated membrane protein-2 (LAMP2). In female patients, a later onset and less severe clinical phenotype have been attributed to the random inactivation of the X chromosome carrying the mutant diseased allele. We generated a patient-specific induced pluripotent stem cell (iPSCs)-based model of Danon disease to evaluate the therapeutic potential of Xi-chromosome reactivation using a DNA methylation inhibitor. METHODS: Using whole-exome sequencing, we identified a nonsense mutation (c.520C>T, exon 4) of the LAMP2 gene in a family with Danon disease. We generated iPSC lines from somatic cells derived from the affected mother and her 2 sons, and we then differentiated them into cardiomyocytes (iPSC-CMs) for modeling the histological and functional signatures, including autophagy failure of Danon disease. RESULTS: Our iPSC-CM platform provides evidence that random inactivation of the wild-type and mutant LAMP2 alleles on the X chromosome is responsible for the unusual phenotype in female patients with Danon disease. In vitro, iPSC-CMs from these patients reproduced the histological features and autophagy failure of Danon disease. Administration of the DNA demethylating agent 5-aza-2'-deoxycytidine reactivated the silent LAMP2 allele in iPSCs and iPSC-CMs in female patients with Danon disease and ameliorated their autophagy failure, supporting the application of a patient-specific iPSC platform for disease modeling and drug screening. CONCLUSIONS: Our iPSC-CM platform provides novel mechanistic and therapeutic insights into the contribution of random X chromosome inactivation to disease phenotype in X-linked Danon disease.

Patient-specific induced-pluripotent stem cells-derived cardiomyocytes recapitulate the pathogenic phenotypes of dilated cardiomyopathy due to a novel DES mutation identified by whole exome sequencing.

In this paper, we report a novel heterozygous mutation of A285V codon conversion on exon 4 of the desmin (DES), using whole exome sequencing (WES) in an isolated proband with documented dilated cardiomyopathy (DCM). This mutation is predicted to cause three-dimensional structure changes of DES. Immunohistological and electron microscopy studies demonstrated diffuse abnormal DES aggregations in DCM-induced-pluripotent stem cell (iPSC)-derived cardiomyocytes, and control-iPSC-derived cardiomyocytes transduced with A285V-DES. DCM-iPSC-derived cardiomyocytes also exhibited functional abnormalities in vitro. This is the first demonstration that patient-specific iPSC-derived cardiomyocytes can be used to provide histological and functional confirmation of a suspected genetic basis for DCM identified by WES.

Impact of overactive bladder on quality of life and resource use: results from Korean Burden of Incontinence Study (KOBIS).

BACKGROUND: To evaluate the impact of overactive bladder (OAB) on quality of life (QOL), resource use and productivity loss in patients recruited from six hospitals in Korea. METHODS: This cross-sectional survey recruited 625 OAB patients between July to December 2013. Patients were categorised into four groups based on the average number of urinary incontinence (UI) episodes over the past three days (0, 1, 2-3 and ≥4 UI/day). QOL was measured using the Incontinence-Specific Quality of Life Instrument (I-QOL), the Overactive Bladder Questionnaire (OAB-q), and a generic health-related utility instrument (EQ-5D). Information on hospital and clinic visit frequency, and continence pads use were also collected. Work productivity was assessed using the Work Productivity and Activity Impairment (WPAI) questionnaire. Between group differences were assessed using ANOVA. Multivariable regression analyses were performed to examine the independent effects of OAB symptoms on QOL. RESULTS: Severity of UI showed a significant linear relationship with QOL, with clinically meaningful differences between each UI severity category. Compared to the dry category, patients in the most severe category (≥4 UI/day) had significantly lower I-QOL scores (69.8 vs 42.6; p < 0.0001), greater symptom bother on the OAB-q (30.4 vs 64.6; p < 0.0001), and poorer EQ-5D utility (0.848 vs 0.742; p < 0.001). Multivariable analyses showed that UI severity, frequency, urgency, and nocturia are independently associated with poorer QOL. Incontinence severity is also significantly associated with cost of incontinence pads (p < 0.0001), and a greater interference with work and regular activities (p = 0.001), however, no significant difference in hospital and clinic visits were observed. CONCLUSION: Severity of UI is a key contributor to the disease burden of OAB in Korean patients, even after taking into account the impact of other symptoms associated with OAB.

Modeling of Friedreich ataxia-related iron overloading cardiomyopathy using patient-specific-induced pluripotent stem cells.

Friedreich ataxia (FRDA), a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy, is due to GAA repeat expansions within the first intron of the frataxin (FXN) gene encoding the mitochondrial protein involved in iron-sulfur cluster biosynthesis. The triplet codon repeats lead to heterochromatin-mediated gene silencing and loss of frataxin. Nevertheless, inadequacy of existing FRDA-cardiac cellular models limited cardiomyopathy studies. We tested the hypothesis that iron homeostasis deregulation accelerates reduction in energy synthesis dynamics which contributes to impaired cardiac calcium homeostasis and contractile force. Silencing of FXN expressions occurred both in somatic FRDA-skin fibroblasts and two of the induced pluripotent stem cells (iPSC) clones; a sign of stress condition was shown in FRDA-iPSC cardiomyocytes with disorganized mitochondrial network and mitochondrial DNA (mtDNA) depletion; hypertrophic cardiac stress responses were observed by an increase in α-actinin-positive cell sizes revealed by FACS analysis as well as elevation in brain natriuretic peptide (BNP) gene expression; the intracellular iron accumulated in FRDA cardiomyocytes might be due to attenuated negative feedback response of transferring receptor (TSFR) expression and positive feedback response of ferritin (FTH1); energy synthesis dynamics, in terms of ATP production rate, was impaired in FRDA-iPSC cardiomyocytes, which were prone to iron overload condition. Energetic insufficiency determined slower Ca(2+) transients by retarding calcium reuptake to sarcoplasmic reticulum (SR) and impaired the positive inotropic and chronotropic responses to adrenergic stimulation. Our data showed for the first time that FRDA-iPSCs cardiac derivatives represent promising models to study cardiac stress response due to impaired iron homeostasis condition and mitochondrial damages. The cardiomyopathy phenotype was accelerated in an iron-overloaded condition early in calcium homeostasis aspect.

Modeling abnormal early development with induced pluripotent stem cells from aneuploid syndromes.

Many human diseases share a developmental origin that manifests during childhood or maturity. Aneuploid syndromes are caused by supernumerary or reduced number of chromosomes and represent an extreme example of developmental disease, as they have devastating consequences before and after birth. Investigating how alterations in gene dosage drive these conditions is relevant because it might help treat some clinical aspects. It may also provide explanations as to how quantitative differences in gene expression determine phenotypic diversity and disease susceptibility among natural populations. Here, we aimed to produce induced pluripotent stem cell (iPSC) lines that can be used to improve our understanding of aneuploid syndromes. We have generated iPSCs from monosomy X [Turner syndrome (TS)], trisomy 8 (Warkany syndrome 2), trisomy 13 (Patau syndrome) and partial trisomy 11;22 (Emanuel syndrome), using either skin fibroblasts from affected individuals or amniocytes from antenatal diagnostic tests. These cell lines stably maintain the karyotype of the donors and behave like embryonic stem cells in all tested assays. TS iPSCs were used for further studies including global gene expression analysis and tissue-specific directed differentiation. Multiple clones displayed lower levels of the pseudoautosomal genes ASMTL and PPP2R3B than the controls. Moreover, they could be transformed into neural-like, hepatocyte-like and heart-like cells, but displayed insufficient up-regulation of the pseudoautosomal placental gene CSF2RA during embryoid body formation. These data support that abnormal organogenesis and early lethality in TS are not caused by a tissue-specific differentiation blockade, but rather involves other abnormalities including impaired placentation.

Upregulation of a local renin-angiotensin system in the rat carotid body during chronic intermittent hypoxia.

The carotid body (CB) plays an important role in the alteration of cardiorespiratory activity in chronic intermittent hypoxia (IH) associated with sleep-disordered breathing, which may be mediated by local expression of the renin-angiotensin system (RAS). We hypothesized a pathogenic role for IH-induced RAS expression in the CB. The CB expression of RAS components was examined in rats exposed to IH resembling a severe sleep-apnoeic condition for 7 days. In situ hybridization showed an elevated expression of angiotensinogen in the CB glomus cells in the hypoxic group when compared with the normoxic control group. Immunohistochemical studies and Western blot analysis revealed increases in the protein level of both angiotensinogen and angiotensin II type 1 (AT1) receptors in the hypoxic group, which were localized to the glomic clusters containing tyrosine hydroxylase. RT-PCR studies confirmed that levels of the mRNA expression of angiotensinogen, angiotensin-converting enzyme, AT1a and AT2 receptors were significantly increased in the CBs of the hypoxic rats. Functionally, the [Ca(2+)]i response to exogenous angiotensin II was enhanced in fura-2-loaded glomus cells dissociated from hypoxic rats when compared with those of the normoxic control animals. Pretreatment with losartan, but not PD123319, abolished the angiotensin II-induced [Ca(2+)]i response, suggesting an involvement of AT1 receptors. Moreover, daily treatment of the IH group of rats with losartan attenuated the levels of oxidative stress, gp91(phox) expression and macrophage infiltration in the CB. Collectively, the upregulated local RAS expression could play a pathogenic role in the augmented CB activity and local inflammation via AT1 receptor activation during IH conditions in patients with sleep-disordered breathing.

Mapping of incontinence quality of life (I-QOL) scores to assessment of quality of life 8D (AQoL-8D) utilities in patients with idiopathic overactive bladder.

BACKGROUND: The Incontinence Quality of Life (I-QOL) questionnaire is a commonly used and validated incontinence specific QOL instrument. The objective of this study is to develop an algorithm to map I-QOL to the Assessment of Quality of Life (AQoL) 8D utility instrument in patients with idiopathic overactive bladder (iOAB). METHODS: I-QOL and AQoL-8D scores were collected in a survey of 177 Australian adults with urinary incontinence due to iOAB. Three statistical methods were used for estimation, namely ordinary least squares (OLS) regression, the robust MM-estimator, and the generalised linear models (GLM). Each included a range of explanatory variables. Model performance was assessed using key goodness-of-fit measures in the validation dataset. RESULTS: The I-QOL total score and AQoL-8D utility scores were positively correlated (r = 0.50, p < 0.0001). Similarly, the three sub-scales of the I-QOL were correlated with the eight dimensions and two super-dimensions of the AQoL-8D. The GLM estimator, with I-QOL total score as the explanatory variable exhibited the best precision (MAE = 0.15 and RMSE = 0.18) with a mapping function given by AQoL-8D = exp(-1.28666 + 1.011072*I-QOL/100). CONCLUSIONS: The mapping algorithm developed in this study allows the derivation of AQoL-8D utilities from I-QOL scores. The algorithm allows the calculation of preference-based QOL scores for use in cost-utility analyses to assess the impact of interventions in urinary incontinence.

The Pathogenic Mechanisms of and Novel Therapies for Lamin A/C-Related Dilated Cardiomyopathy Based on Patient-Specific Pluripotent Stem Cell Platforms and Animal Models.

Variants (pathogenic) of the LMNA gene are a common cause of familial dilated cardiomyopathy (DCM), which is characterised by early-onset atrioventricular (AV) block, atrial fibrillation and ventricular tachyarrhythmias (VTs), and progressive heart failure. The unstable internal nuclear lamina observed in LMNA-related DCM is a consequence of the disassembly of lamins A and C. This suggests that LMNA variants produce truncated or alternative forms of protein that alter the nuclear structure and the signalling pathway related to cardiac muscle diseases. To date, the pathogenic mechanisms and phenotypes of LMNA-related DCM have been studied using different platforms, such as patient-specific induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs) and transgenic mice. In this review, point variants in the LMNA gene that cause autosomal dominantly inherited forms of LMNA-related DCM are summarised. In addition, potential therapeutic targets based on preclinical studies of LMNA variants using transgenic mice and human iPSC-CMs are discussed. They include mitochondria deficiency, variants in nuclear deformation, chromatin remodelling, altered platelet-derived growth factor and ERK1/2-related pathways, and abnormal calcium handling.

Cost-utility analysis of sacituzumab govitecan versus chemotherapy for the treatment of metastatic triple-negative breast cancer in Singapore.

OBJECTIVE: To assess the cost-effectiveness of sacituzumab govitecan for treating relapsed or refractory metastatic triple-negative breast cancer (TNBC) in Singapore. METHODS: A three-state partitioned survival model was developed to evaluate the cost-effectiveness of sacituzumab govitecan from a healthcare system perspective over 5 years. Clinical inputs were obtained from the ASCENT trial. Health state utilities were retrieved from the literature and direct costs were sourced from public healthcare institutions in Singapore. Sensitivity and scenario analyses were conducted to explore the impact of uncertainties and assumptions on cost-effectiveness results. RESULTS: Compared with single-agent chemotherapy, sacituzumab govitecan was associated with a base-case incremental cost-effectiveness ratio (ICER) of S$328,000 (US$237,816) per quality-adjusted life year (QALY) gained. One-way sensitivity analyses showed that the ICER was most sensitive to the cost of sacituzumab govitecan and progression-free utility values. Regardless of variation in these parameters, the ICER remained high, and a substantial price reduction was required to reduce the ICER. CONCLUSION: At its current price, sacituzumab govitecan does not represent a cost-effective treatment for relapsed or refractory metastatic TNBC in Singapore. Our findings will be useful to inform funding decisions alongside other factors including clinical effectiveness, safety, and budget impact considerations.

Impact of Value-Driven Healthcare Strategies for Biosimilar Adoption: The Singapore Story.

BACKGROUND: Healthcare sustainability is a global challenge. Various value-driven healthcare strategies have been implemented by Singapore's national health technology assessment (HTA) agency, the Agency for Care Effectiveness (ACE). Considering the high and growing expenditure on biologics, strategies have been implemented to drive the use of biosimilars. As Singapore has reached the 5-year mark since the subsidy listing of the first monoclonal antibody biosimilar infliximab, this review aimed to evaluate the impact of these strategies on the changes in adoption rates, utilisation, spending and cost savings for biosimilars in the public healthcare sector. METHODS: A retrospective cross-sectional study was conducted using aggregated drug utilisation data from all public healthcare institutions. Five monoclonal antibodies with biosimilars, namely infliximab, adalimumab, trastuzumab, rituximab and bevacizumab, were included in this study. The outcomes evaluated were the monthly trends for utilisation volume, proportion attributed to biosimilar use, and drug spending up to December 2022. The simulated cost savings associated with biosimilar adoption were also reported. RESULTS: After subsidy implementation, an upward trend in biosimilar use and proportion attributed to biosimilar adoption was observed, while spending reduced substantially. The adoption rate of most biosimilars reached more than 95% within 1 year of listing. Drugs with more than one approved biosimilar brand at the time of subsidy listing reported substantial price reductions of over 80%. Overall, spending for the five monoclonal antibodies have significantly reduced after biosimilar subsidy listing, with an estimated cumulative cost savings of $136 million over 5 years. CONCLUSION: Value-driven healthcare strategies implemented in Singapore's public healthcare institutions have contributed to high adoption rates of biosimilars and have improved affordable access through lower treatment costs. This in turn has led to significant cost savings to the healthcare system.