Evaluating disease-modifying agents: a simulation framework for Alzheimer's disease

Predicting the Societal Value of Lecanemab in Early Alzheimer's Disease in Japan: A Patient-Level Simulation

INTRODUCTION

Alzheimer's disease (AD), a neurodegenerative disorder that progresses from mild cognitive impairment (MCI) to dementia, is responsible for significant burden on caregivers and healthcare systems. In this study, data from the large phase III CLARITY AD trial were used to estimate the societal value of lecanemab plus standard of care (SoC) versus SoC alone against a range of willingness-to-pay (WTP) thresholds from a healthcare and societal perspective in Japan.

METHODS

A disease simulation model was used to evaluate the impact of lecanemab on disease progression in early AD based on data from the phase III CLARITY AD trial and published literature. The model used a series of predictive risk equations based on clinical and biomarker data from the Alzheimer's Disease Neuroimaging Initiative and Assessment of Health Economics in Alzheimer's Disease II study. The model predicted key patient outcomes, including life years (LYs), quality-adjusted life years (QALYs), and total healthcare and informal costs of patients and caregivers.

RESULTS

Over a lifetime horizon, patients treated with lecanemab plus SoC gained an additional 0.73 LYs compared with SoC alone (8.50 years vs. 7.77 years). Lecanemab, with an average treatment duration of 3.68 years, was found to be associated with a 0.91 increase in patient QALYs and a total increase of 0.96 when accounting for caregiver utility. The estimated value of lecanemab varied according to the WTP thresholds (JPY 5-15 million per QALY gained) and the perspective employed. From the narrow healthcare payer's perspective, it ranged from JPY 1,331,305 to JPY 3,939,399. From the broader healthcare payer's perspective, it ranged from JPY 1,636,827 to JPY 4,249,702, while from the societal perspective, it ranged from JPY 1,938,740 to JPY 4,675,818.

CONCLUSION

The use of lecanemab plus SoC would improve health and humanistic outcomes with reduced economic burden for patients and caregivers with early AD in Japan.

A Path to Improved Alzheimer's Care: Simulating Long-Term Health Outcomes of Lecanemab in Early Alzheimer's Disease from the CLARITY AD Trial

INTRODUCTION

Alzheimer's disease (AD), a progressive neurodegenerative disease, is the main cause of dementia and one of the leading causes of death for elderly people in the USA. Lecanemab is a humanized IgG1 monoclonal antibody targeting amyloid protofibrils for the treatment of early AD [i.e., mild cognitive impairment (MCI) or mild AD dementia]. In a recent 18-month phase III trial, using a double-blind, placebo-controlled design, lecanemab treatment led to reduced brain amyloid burden and significant improvements in cognitive and functional abilities in individuals with early AD.

METHODS

An evidence-based patient-level disease simulation model was updated to estimate the long-term health outcomes of lecanemab plus standard of care (SoC) compared to SoC alone in patients with early AD and evidence of brain amyloid burden, using recent phase III trial data and published literature. The disease progression is described by changes in the underlying biomarkers of AD, including measures of amyloid and tau, and their connection to the clinical presentation of the disease assessed through various patient-level scales of cognition and function.

RESULTS

Lecanemab treatment was estimated to slow the progression of AD to moderate and severe stages and reduce the time spent in these more advanced states. In individuals with early AD, lecanemab plus SoC was associated with a gain of 0.71 quality-adjusted life-years (QALYs), a 2.95-year delay in mean time to progression to AD dementia, a reduction of 0.11 years in institutional care, and an additional 1.07 years in community care as shown in the base-case study. Improved health outcomes were demonstrated with lecanemab treatment when initiated earlier based on age, disease severity, or tau pathology, resulting in estimated gains in QALYs ranging from 0.77 to 1.09 years, compared to 0.4 years in the mild AD dementia subset, as shown by the model.

CONCLUSION

The study findings demonstrate the potential clinical value of lecanemab for individuals with early AD by slowing down disease progression and prolonging time in earlier stages of disease, which significantly benefits not only patients and caregivers but also society overall.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03887455.

Estimated Societal Value of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with memory, cognitive, and behavioral deficits, and brings significant economic burden on caregivers and healthcare systems. This study aims to estimate the long-term societal value of lecanemab plus standard of care (SoC) versus SoC alone, corresponding to a range of willingness-to-pay (WTP) thresholds based on the phase III CLARITY AD trial readouts from both the US payer and societal perspectives.

METHODS

An evidence-based model was developed to simulate the effects of lecanemab on disease progression in early AD using interconnected predictive equations based on longitudinal clinical and biomarker data derived from the Alzheimer's Disease Neuroimaging Initiative (ADNI). The model was informed with the results of the phase III CLARITY AD trial and published literature. Key model outcomes included patient life-years (LYs), quality-adjusted life-years (QALYs), and total costs of both the direct and indirect costs of patients and caregivers over a lifetime horizon.

RESULTS

Patients treated with lecanemab plus SoC gained an additional 0.62 years of life versus SoC alone (6.23 years vs. 5.61 years). The mean time on lecanemab was 3.91 years, and the treatment was associated with an increase in patient QALYs of 0.61 and an increase in total QALYs of 0.64 when both patient and caregiver utilities were considered. The model estimated that the annual value of lecanemab for the US payer perspective was US$18,709-35,678 ($19,710-37,351 for societal perspective) at the WTP threshold of $100,000-200,000 per QALY gained, respectively. Scenario analyses of patient subgroups, time horizon, input sources, treatment stopping rules, and treatment dosing were conducted to explore the impact of alternative assumptions on the model results.

CONCLUSION

The economic study suggested that lecanemab plus SoC would improve health and humanistic (quality of life) outcomes and reduce economic burden for patients and caregivers in early AD.

A Simulation Model to Evaluate the Potential Impact of Disease-Modifying Treatments on Burden of Illness in Alzheimer's Disease

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disease that places a substantial burden on patients, caregivers, and society. The advent of disease-modifying treatments (DMTs) would represent a major advancement in the management of AD, particularly in early AD. It is important to understand the potential value of these therapies to individuals and society.

METHODS

A modeling framework was developed to estimate the potential clinical and economic burden of AD in the USA by simulating the impact, relative to that of usual care, of a DMT with hypothesized availability beginning from 2022. The model assessed AD epidemiology, disease progression, and burden of illness from 2020 to 2050. Model outcomes included the total number of Americans with mild cognitive impairment (MCI) due to AD and mild, moderate, or severe AD dementia in community or residential care settings and their associated care costs, including direct medical and non-medical costs for healthcare resource use and indirect costs for caregiving.

RESULTS

A hypothetical DMT was compared to the usual care under different effect scenarios based on delay in onset of AD (1, 3, and 5 years) and DMT uptake (25%, 50%, and 100%). A delay in the onset of AD by 5 years would reduce the prevalence of AD in 2050 by 6%, 12%, and 25%, resulting in savings of $0.783, $1.566, and $3.132 trillion from 2022 to 2050 for the 25%, 50%, and 100% uptake scenarios, respectively.

CONCLUSION

This analysis demonstrated that DMTs that provide even small delays in the onset of AD can lead to an increase in disease-free years and sizable savings in the cost of care, providing significant benefits to patients, caregivers, and society.

The Potential Economic Value of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

INTRODUCTION

Alzheimer's disease (AD) is a progressive, neurodegenerative disease that affects memory, thinking, and behavior and places a substantial economic burden on caregivers and healthcare systems. This early-phase study aimed to model lecanemab, a humanized monoclonal antibody targeting amyloid protofibrils, for patients with early AD, and estimate the potential value-based price (VBP) of lecanemab + standard of care (SoC) compared to SoC alone given an expected product profile of lecanemab informed by data from a phase II trial from payer and societal perspectives using a broad range of willingness-to-pay (WTP) thresholds in the USA.

METHODS

A disease simulation model was used to capture how key AD pathology components relate to the clinical and economic presentation of AD. The effects of disease modification and early intervention on disease progression were simulated on the basis of BAN2401-G000-201 trial data as well as published literature. Model outcomes included patient and caregiver quality-adjusted life years (QALYs), total life years, and total care costs including direct medical and non-medical costs for healthcare resource use and indirect costs for caregiving over a lifetime horizon.

RESULTS

Lecanemab + SoC was predicted to result in a gain of 0.61 QALYs (societal, 0.64) and a $8707 decrease in total non-treatment costs (societal, $11,214) vs. SoC alone for patients with early AD. For a WTP threshold range of $50,000 to $200,000 per QALY gained, the potential annual VBP of lecanemab was estimated at $9249 (societal, $10,400) to $35,605 (societal, $38,053), respectively. Other patient subsets, treatment stopping rules, and dosing regimens were used to assess the sensitivity of the VBP estimates.

CONCLUSION

The early model predicted that lecanemab would potentially improve long-term health outcomes and reduce formal and informal care costs, resulting in a range of VBPs that reflect the value of lecanemab to society.

New bis-thiazolidinone based chalcone analogues as effective inhibitors of Alzheimer's disease: Synthesis, molecular docking, acetylcholinesterase and butyrylcholinesterase study

A series of twenty bis -thiazolidinone based chalcone scaffolds (1-20) were synthesized and characterized by using various spectroscopic tools such as HR-EI-MS, 1 HNMR, 13 CNMR and were screened in vitro for their AChE and BuChE inhibition profile. It was noteworthy, that all the synthetic analogues (except analogues 10, 12 and 1 4 , which are found to be inactive) showed moderate to good inhibitory potentials on screening against AchE and BuChE enzymes with IC 50 values ranging from 0.10 ±0.050 to 7.60 ± 0.10 µM and 0.10 ± 0.050µM to 10.70 ± 0.20 µM as compared to standard Donepezil inhibitor (IC 50 = 0.016 ± 0.12 µM), (IC 50 = 4.5 ± 0.11 µM).  Among the current series, analogue 20 (IC 50 = 0.10 ± 0.050µM), (IC 50 = 0.10 ± 0.050µM) bearing trihydroxy substitutions on ortho -, meta - and para -position of both rings A and B , respectively was found to be the most active inhibitor of AChE and BuChE enzymes . Analogue 19 (IC 50 = 0.20 ± 0.050 µM), (IC 50 = 0.20 ± 0.050µM) bearing dihydroxy substitutions on ortho - and meta -position of both ring A and ring B respectively, was identified as the second most potent inhibitor against both these enzymes. Potent analogs were further subjected to molecular docking study to identify the binding interactions with enzymes active site. SAR study was done for all the analogues mostly based on substitution pattern on both ring A and B respectively.

Long-Term Health Outcomes of Lecanemab in Patients with Early Alzheimer's Disease Using Simulation Modeling

Introduction

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease and is the most common cause of dementia. Lecanemab is a humanized monoclonal antibody targeting amyloid protofibrils for the treatment of early AD. In the phase II BAN2401-G000-201 trial (NCT01767311), lecanemab reduced amyloid accumulated in the brain and slowed progression on key global and cognitive scales evaluating efficacy after 18 months of treatment.

Methods

A disease simulation model was used to predict the long-term clinical outcomes of lecanemab for patients with early AD [i.e., mild cognitive impairment (MCI) due to AD and mild AD dementia] on the basis of BAN2401-G000-201 trial data and published literature. The model captures the pathophysiology and management of AD, with a focus on simulating the effects of disease modification and early intervention on disease progression. The model compares lecanemab in addition to standard of care (SoC) versus SoC alone.

Results

Lecanemab treatment was estimated to slow the rate of disease progression, resulting in an extended duration of MCI due to AD and mild AD dementia and shortened duration in moderate and severe AD dementia. The mean time to mild, moderate, and severe AD dementia was longer for patients in the lecanemab + SoC group than for patients in the SoC group by 2.51, 3.13, and 2.34 years, respectively. On base-case analysis, lecanemab was associated with 0.73 incremental life years (LY) and 0.75 incremental quality-adjusted LYs (QALY), and the caregiver QALYs lost was reduced by 0.03 years. The model also predicted a lower lifetime probability of admission to institutional care in lecanemab + SoC versus SoC group (25% versus 31%).

Conclusion

The model results demonstrate the potential clinical value of lecanemab for patients with early AD and how it can slow the rate of disease progression and reduce the lifetime probability for institutionalized care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00350-y.

Evaluation of the Cost-effectiveness of Drug Treatment for Alzheimer Disease in a Simulation Model That Includes Caregiver and Societal Factors

Importance

The possibility of widespread use of a novel effective therapy for Alzheimer disease (AD) will present important clinical, policy, and financial challenges.

Objective

To describe how including different patient, caregiver, and societal treatment-related factors affects estimates of the cost-effectiveness of a hypothetical disease-modifying AD treatment.

Design, Setting, and Participants

In this economic evaluation, the Alzheimer Disease Archimedes Condition Event Simulator was used to simulate the prognosis of a hypothetical cohort of patients selected from the Alzheimer Disease Neuroimaging Initiative database who received the diagnosis of mild cognitive impairment (MCI). Scenario analyses that varied costs and quality of life inputs relevant to patients and caregivers were conducted. The analysis was designed and conducted from June 15, 2019, to September 30, 2020.

Exposures

A hypothetical drug that would delay progression to dementia in individuals with MCI compared with usual care.

Main Outcomes and Measures

Incremental cost-effectiveness ratio (ICER), measured by cost per quality-adjusted life-year (QALY) gained.

Results

The model included a simulated cohort of patients who scored between 24 and 30 on the Mini-Mental State Examination and had a global Clinical Dementia Rating scale of 0.5, with a required memory box score of 0.5 or higher, at baseline. Using a health care sector perspective, which included only individual patient health care costs, the ICER for the hypothetical treatment was $192 000 per QALY gained. The result decreased to $183 000 per QALY gained in a traditional societal perspective analysis with the inclusion of patient non-health care costs. The inclusion of estimated caregiver health care costs produced almost no change in the ICER, but the inclusion of QALYs gained by caregivers led to a substantial reduction in the ICER for the hypothetical treatment, to $107 000 per QALY gained in the health sector perspective. In the societal perspective scenario, with the broadest inclusion of patient and caregiver factors, the ICER decreased to $74 000 per added QALY.

Conclusions and Relevance

The findings of this economic evaluation suggest that policy makers should be aware that efforts to estimate and include the effects of AD treatments outside those on patients themselves can affect the results of the cost-effectiveness analyses that often underpin assessments of the value of new treatments. Further research and debate on including these factors in assessments that will inform discussions on fair pricing for new treatments are needed.

Synthesis, In Silico and In Vitro Evaluation of Some Flavone Derivatives for Acetylcholinesterase and BACE-1 Inhibitory Activity

Acetylcholinesterase (AChE) and β-secretase (BACE-1) have become attractive therapeutic targets for Alzheimer’s disease (AD). Flavones are flavonoid derivatives with various bioactive effects, including AChE and BACE-1 inhibition. In the present work, a series of 14 flavone derivatives was synthesized in relatively high yields (35–85%). Six of the synthetic flavones (B4, B5, B6, B8, D6 and D7) had completely new structures. The AChE and BACE-1 inhibitory activities were tested, giving pIC₅₀ 3.47–4.59 (AChE) and 4.15–5.80 (BACE-1). Three compounds (B3, D5 and D6) exhibited the highest biological effects on both AChE and BACE-1. A molecular docking investigation was conducted to explain the experimental results. These molecules could be employed for further studies to discover new structures with dual action on both AChE and BACE-1 that could serve as novel therapies for AD.

Supporting good quality, community-based end-of-life care for people living with dementia: the SEED research programme including feasibility RCT

Background

In the UK, most people with dementia die in the community and they often receive poorer end-of-life care than people with cancer.

Objective

The overall aim of this programme was to support professionals to deliver good-quality, community-based care towards, and at, the end of life for people living with dementia and their families.

Design

The Supporting Excellence in End-of-life care in Dementia (SEED) programme comprised six interlinked workstreams. Workstream 1 examined existing guidance and outcome measures using systematic reviews, identified good practice through a national e-survey and explored outcomes of end-of-life care valued by people with dementia and family carers (n = 57) using a Q-sort study. Workstream 2 explored good-quality end-of-life care in dementia from the perspectives of a range of stakeholders using qualitative methods (119 interviews, 12 focus groups and 256 observation hours). Using data from workstreams 1 and 2, workstream 3 used co-design methods with key stakeholders to develop the SEED intervention. Worksteam 4 was a pilot study of the SEED intervention with an embedded process evaluation. Using a cluster design, we assessed the feasibility and acceptability of recruitment and retention, outcome measures and our intervention. Four general practices were recruited in North East England: two were allocated to the intervention and two provided usual care. Patient recruitment was via general practitioner dementia registers. Outcome data were collected at baseline, 4, 8 and 12 months. Workstream 5 involved economic modelling studies that assessed the potential value of the SEED intervention using a contingent valuation survey of the general public (n = 1002). These data informed an economic decision model to explore how the SEED intervention might influence care. Results of the model were presented in terms of the costs and consequences (e.g. hospitalisations) and, using the contingent valuation data, a cost–benefit analysis. Workstream 6 examined commissioning of end-of-life care in dementia through a narrative review of policy and practice literature, combined with indepth interviews with a national sample of service commissioners (n = 20).

Setting

The workstream 1 survey and workstream 2 included services throughout England. The workstream 1 Q-sort study and workstream 4 pilot trial took place in North East England. For workstream 4, four general practices were recruited; two received the intervention and two provided usual care.

Results

Currently, dementia care and end-of-life care are commissioned separately, with commissioners receiving little formal guidance and training. Examples of good practice rely on non-recurrent funding and leadership from an interested clinician. Seven key components are required for good end-of-life care in dementia: timely planning discussions, recognising end of life and providing supportive care, co-ordinating care, effective working with primary care, managing hospitalisation, continuing care after death, and valuing staff and ongoing learning. Using co-design methods and the theory of change, the seven components were operationalised as a primary care-based, dementia nurse specialist intervention, with a care resource kit to help the dementia nurse specialist improve the knowledge of family and professional carers. The SEED intervention proved feasible and acceptable to all stakeholders, and being located in the general practice was considered beneficial. None of the outcome measures was suitable as the primary outcome for a future trial. The contingent valuation showed that the SEED intervention was valued, with a wider package of care valued more than selected features in isolation. The SEED intervention is unlikely to reduce costs, but this may be offset by the value placed on the SEED intervention by the general public.

Limitations

The biggest challenge to the successful delivery and completion of this research programme was translating the ‘theoretical’ complex intervention into practice in an ever-changing policy and service landscape at national and local levels. A major limitation for a future trial is the lack of a valid and relevant primary outcome measure to evaluate the effectiveness of a complex intervention that influences outcomes for both individuals and systems.

Conclusions

Although the dementia nurse specialist intervention was acceptable, feasible and integrated well with existing care, it is unlikely to reduce costs of care; however, it was highly valued by all stakeholders (professionals, people with dementia and their families) and has the potential to influence outcomes at both an individual and a systems level.

Future work

There is no plan to progress to a full randomised controlled trial of the SEED intervention in its current form. In view of new National Institute for Health and Care Excellence dementia guidance, which now recommends a care co-ordinator for all people with dementia, the feasibility of providing the SEED intervention throughout the illness trajectory should be explored. Appropriate outcome measures to evaluate the effectiveness of such a complex intervention are needed urgently.

Trial registration

Current Controlled Trials ISRCTN21390601.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research, Vol. 8, No. 8. See the NIHR Journals Library website for further project information.

Computer simulation of dementia care demand heterogeneity using hybrid simulation methods: improving population-level modelling with individual patient decline trajectories

OBJECTIVES

The aim of the study was to model dementia prevalence and outcomes within an ageing population using a novel hybrid simulation model that simultaneously takes population-level and patient-level perspectives to better inform dementia care service planning, taking into account severity progression variability.

STUDY DESIGN

This is a simulation study.

METHODS

We developed a hybrid computer simulation combining different methods to best represent population and individual dementia dynamics. Individual patient outcomes are aggregated into three progression rate types to report the effects of severity progression variability and intervention benefits.

RESULTS

Fast progression of dementia severity is associated with higher annual care cost and short overall survival duration. Those patients are more likely to develop moderate to severe symptoms more quickly, highlighting a need for more urgent provision of appropriate care services. Slower severity progression is associated with lower annual care costs, but longer survival requires higher overall financial provision. Although lifestyle interventions reduce overall care costs, treatment and lifestyle intervention benefits are modest at the population level.

CONCLUSIONS

Individual variation of dementia decline is an important factor to include in planning adequate levels of care services and to ensure timely and appropriate service availability. Hybrid simulation models provide useful insights at the population and individual level, supporting effective decision-making.

Synthesis, In Silico and In Vitro Evaluation for Acetylcholinesterase and BACE-1 Inhibitory Activity of Some N-Substituted-4-Phenothiazine-Chalcones

Acetylcholinesterase (AChE) and beta-secretase (BACE-1) are two attractive targets in the discovery of novel substances that could control multiple aspects of Alzheimer’s disease (AD). Chalcones are the flavonoid derivatives with diverse bioactivities, including AChE and BACE-1 inhibition. In this study, a series of N-substituted-4-phenothiazine-chalcones was synthesized and tested for AChE and BACE-1 inhibitory activities. In silico models, including two-dimensional quantitative structure–activity relationship (2D-QSAR) for AChE and BACE-1 inhibitors, and molecular docking investigation, were developed to elucidate the experimental process. The results indicated that 13 chalcone derivatives were synthesized with relatively high yields (39–81%). The bioactivities of these substances were examined with pIC₅₀ 3.73–5.96 (AChE) and 5.20–6.81 (BACE-1). Eleven of synthesized chalcones had completely new structures. Two substances AC4 and AC12 exhibited the highest biological activities on both AChE and BACE-1. These substances could be employed for further researches. In addition to this, the present study results suggested that, by using a combination of two types of predictive models, 2D-QSAR and molecular docking, it was possible to estimate the biological activities of the prepared compounds with relatively high accuracy.

Design of Curcumin and Flavonoid Derivatives with Acetylcholinesterase and Beta-Secretase Inhibitory Activities Using in Silico Approaches

Acetylcholinesterase (AChE) and beta-secretase (BACE-1) are the two crucial enzymes involved in the pathology of Alzheimer's disease. The former is responsible for many defects in cholinergic signaling pathway and the latter is the primary enzyme in the biosynthesis of beta-amyloid as the main component of the amyloid plaques. These both abnormalities are found in the brains of Alzheimer's patients. In this study, in silico models were developed, including 3D-pharmacophore, 2D-QSAR (two-dimensional quantitative structure-activity relationship), and molecular docking, to screen virtually a database of compounds for AChE and BACE-1 inhibitory activities. A combinatorial library containing more than 3 million structures of curcumin and flavonoid derivatives was generated and screened for drug-likeness and enzymatic inhibitory bioactivities against AChE and BACE-1 through the validated in silico models. A total of 47 substances (two curcumins and 45 flavonoids), with remarkable predicted pIC₅₀ values against AChE and BACE-1 ranging from 4.24-5.11 (AChE) and 4.52-10.27 (BACE-1), were designed. The in vitro assays on AChE and BACE-1 were performed and confirmed the in silico results. The study indicated that, by using in silico methods, a series of curcumin and flavonoid structures were generated with promising predicted bioactivities. This would be a helpful foundation for the experimental investigations in the future. Designed compounds which were the most feasible for chemical synthesis could be potential candidates for further research and lead optimization.

The Economic Impact of New Therapeutic Interventions on Neuropsychiatric Inventory (NPI) Symptom Scores in Patients with Alzheimer Disease

Background/Aims

Few studies have modeled individual Neuropsychiatric Inventory (NPI) symptom scores for Alzheimer disease (AD) patients and assessed the value of therapeutic interventions that can potentially impact them. The main objective of this study was to evaluate the impact of new AD symptomatic treatments on relevant health economic outcomes via their potential effects on cognition and neuropsychiatric symptoms such as depression, irritability, anxiety, and sleep disorder.

Methods

We enhanced the previously published AHEAD model (Assessment of Health Economics in Alzheimer's Disease) by including new variables and functional relations to capture the NPI's individual neuropsychiatric symptoms in addition to the total NPI score. This update allowed us to study the longitudinal effect of improvements in specific NPI subscale scores and the downstream impact on outcomes such as psychiatric medication use, survival, and institutional placement.

Results

The model base-case results showed that a hypothetical treatment with symptomatic effects on anxiety, depression, and irritability NPI subscales was not cost-effective; however, the treatment's cost-effectiveness was improved once a direct link between NPI subscales and mortality was explored or under relatively stronger treatment effects.

Conclusion

Treatments that influence specific symptoms within the overall NPI have the potential to improve patient outcomes in a cost-effective way. This model is a useful tool for evaluating target product profiles of drugs with effect on NPI symptoms in early stages of development.

Alzheimer's disease Archimedes condition-event simulator: Development and validation

Introduction

Several advances have been made in Alzheimer's Disease (AD) modeling, however, there remains a need for a simulator that represents the full scope of disease progression and can be used to study new disease-modifying treatments for early-stage and even prodromal AD.

Methods

We developed AD Archimedes condition-event simulator, a patient-level simulator with a focus on simulating the effects of early interventions through changes in biomarkers of AD. The simulator incorporates interconnected predictive equations derived from longitudinal data sets.

Results

The results of external validations on AD Archimedes condition-event simulator showed that it provides reasonable estimates once compared to literature results on transition to dementia AD, institutionalization, and mortality. A case study comparing a disease-modifying treatment and a symptomatic treatment also showcases the benefits of early treatment.

Discussion

The AD Archimedes condition-event simulator is designed to perform economic evaluation on various interventions through close tracking of disease progression and the related clinical outcomes.

Current issues and future research priorities for health economic modelling across the full continuum of Alzheimer's disease

Available data and models for the health-economic evaluation of treatment in Alzheimer's disease (AD) have limitations causing uncertainty to decision makers. Forthcoming treatment strategies in preclinical or early AD warrant an update on the challenges associated with their economic evaluation. The perspectives of the co-authors were complemented with a targeted review of literature discussing methodological issues and data gaps in AD health-economic modelling. The methods and data available to translate treatment efficacy in early disease into long-term outcomes of relevance to policy makers and payers are limited. Current long-term large-scale data accurately representing the continuous, multifaceted, and heterogeneous disease process are missing. The potential effect of disease-modifying treatment on key long-term outcomes such as institutionalization and death is uncertain but may have great effect on cost-effectiveness. Future research should give priority to collaborative efforts to access better data on the natural progression of AD and its association with key long-term outcomes.

Systematic Review of Model-Based Economic Evaluations of Treatments for Alzheimer's Disease

BACKGROUND

Numerous economic evaluations using decision-analytic models have assessed the cost effectiveness of treatments for Alzheimer's disease (AD) in the last two decades. It is important to understand the methods used in the existing models of AD and how they could impact results, as they could inform new model-based economic evaluations of treatments for AD.

OBJECTIVE

The aim of this systematic review was to provide a detailed description on the relevant aspects and components of existing decision-analytic models of AD, identifying areas for improvement and future development, and to conduct a quality assessment of the included studies.

METHODS

We performed a systematic and comprehensive review of cost-effectiveness studies of pharmacological treatments for AD published in the last decade (January 2005 to February 2015) that used decision-analytic models, also including studies considering patients with mild cognitive impairment (MCI). The background information of the included studies and specific information on the decision-analytic models, including their approach and components, assumptions, data sources, analyses, and results, were obtained from each study. A description of how the modeling approaches and assumptions differ across studies, identifying areas for improvement and future development, is provided. At the end, we present our own view of the potential future directions of decision-analytic models of AD and the challenges they might face.

RESULTS

The included studies present a variety of different approaches, assumptions, and scope of decision-analytic models used in the economic evaluation of pharmacological treatments of AD. The major areas for improvement in future models of AD are to include domains of cognition, function, and behavior, rather than cognition alone; include a detailed description of how data used to model the natural course of disease progression were derived; state and justify the economic model selected and structural assumptions and limitations; provide a detailed (rather than high-level) description of the cost components included in the model; and report on the face-, internal-, and cross-validity of the model to strengthen the credibility and confidence in model results. The quality scores of most studies were rated as fair to good (average 87.5, range 69.5-100, in a scale of 0-100).

CONCLUSION

Despite the advancements in decision-analytic models of AD, there remain several areas of improvement that are necessary to more appropriately and realistically capture the broad nature of AD and the potential benefits of treatments in future models of AD.