Burden of Disease and Current Management of Dementia with Lewy Bodies: A Literature Review

Emerging drugs for dementia with Lewy Bodies: a review of Phase II & III trials

INTRODUCTION

Despite faster cognitive decline and greater negative impact on patients and family caregivers, drug development efforts in Dementia with Lewy Bodies (DLB) fall behind those for Alzheimer's Disease (AD). Current off-label drug DLB treatment options are limited to symptomatic agents developed to address cognitive deficits in AD, motor deficits in Parkinson's Disease, or behavioral symptoms in psychiatric disease. Aided by recent improvements in DLB diagnosis, a new focus on the development of disease-modifying agents (DMA) is emerging.

AREAS COVERED

Driven by evidence supporting different pathological mechanisms in DLB and PDD, this review assesses the evidence on symptomatic drug treatments and describes current efforts in DMA development in DLB. Specifically, our goals were to: (1) review evidence supporting the use of symptomatic drug treatments in DLB; (2) review the current DMA pipeline in DLB with a focus on Phase II and III clinical trials; and (3) identify potential issues with the development of DMA in DLB. Included in this review were completed and ongoing drug clinical trials in DLB registered on ClinicalTrials.gov (no time limits set for the search) or disseminated at the 2023 international conference on Clinical Trials in AD. Drug clinical trials registered in non-US clinical trial registries were not included.

EXPERT OPINION

Adoption of current symptomatic drug treatments used off-label in DLB relied on efficacy of benefits in other disorders rather than evidence from randomized controlled clinical trials. Symptoms remain difficult to manage. Several DMA drugs are currently being evaluated as either repurposing candidates or novel small molecules. Continued improvement in methodological aspects including development of DLB-specific outcome measures and biomarkers is needed to move the field of DMA drug development forward.

Questionnaire survey of satisfaction with medication for five symptom domains of dementia with Lewy bodies among patients, their caregivers, and their attending physicians

BACKGROUND

The real-world status of satisfaction with medication for dementia with Lewy bodies (DLB) has not been elucidated. We assessed the satisfaction of patients with DLB, their caregivers, and their attending physicians (trios) with medication according to the clinical symptom domains of DLB.

METHODS

This was a subanalysis of a cross-sectional, questionnaire-based, survey study of trios. The subanalysis set comprised analysis populations for cognitive impairment, parkinsonism, psychiatric symptoms, sleep-related disorders, and autonomic dysfunction (orthostatic hypotension, constipation, and dysuria). These analysis populations included trios of patients who had any symptom domain and took medication for each symptom domain, and for which all trio data on satisfaction with medication for the symptom domain were available. The degrees of satisfaction with medication were classified as 'satisfied', 'neutral', or 'dissatisfied'.

RESULTS

The analysis set for this study included 110 trios for cognitive impairment, 62 for parkinsonism, 47 for psychiatric symptoms, 29 for sleep-related disorders, none for orthostatic hypotension, 11 for constipation, and seven for dysuria. There were no statistically significant differences in the degree of satisfaction with medication for symptom domains other than parkinsonism and dysuria between patients-caregivers, patients-physicians, and caregivers-physicians. Regarding satisfaction with medication for parkinsonism, significantly more physicians than patients answered 'satisfied' (75.8% vs. 51.6%), and significantly more patients than physicians answered 'neutral' (35.5% vs. 14.5%) (P = 0.013). Regarding satisfaction with medication for dysuria, significantly more caregivers than physicians answered 'satisfied' (100% vs. 28.6%, P = 0.038).

CONCLUSIONS

Satisfaction with medication for symptom domains other than parkinsonism and dysuria was similar among trios. Our results suggest that physicians should pay more attention to patients' satisfaction with medication for parkinsonism, and to caregivers' satisfaction with medication for dysuria to help prevent undermedication.

Disease Progression and Longitudinal Clinical Outcomes of Lewy Body Dementia in the NACC Database

INTRODUCTION

As the identification of Lewy body dementia (LBD) is often confirmed postmortem, there is a paucity of evidence on the progression of disease antemortem. This study aimed to comprehensively assess the course of LBD over time across cognitive, functional, and neuropsychiatric outcomes using real-world data.

METHODS

Adults with at least one visit to an Alzheimer's Disease Center with a diagnosis of mild cognitive impairment/dementia (index date), indication of LBD, and at least one follow-up visit were identified in the National Alzheimer's Coordinating Center database (September 2005-June 2020). Participant characteristics, medication use, comorbidities, and changes in outcomes were assessed over a 5-year follow-up period and stratified by disease severity based on the Clinical Dementia Rating (CDR®) Dementia Staging Instrument-Sum of Boxes (CDR-SB) score at index.

RESULTS

A total of 2052 participants with LBD (mean age at index 73.4 years) were included (mild, 219; moderate, 988; severe, 845). Mean annualized increase over 5 years was 0.9 points for CDR-Global Score, 5.6 points for CDR-SB, 10.4 points for the Functional Activities Questionnaire, and 2.0 points for the Neuropsychiatric Inventory-Questionnaire. Disease progression was greater among participants with moderate and severe LBD at index compared with those with mild LBD.

CONCLUSION

Participants with LBD experienced decline across all outcomes over time, and impairment increased with disease severity. Findings highlight the substantial clinical burden associated with LBD and the importance of earlier diagnosis and effective treatment. Further research is needed to understand the predictors of cognitive and functional decline in LBD which may help inform clinical trials.

Costs During the Last Five Years of Life for Patients with Clinical and Pathological Confirmed Diagnosis of Lewy Body Dementia and Alzheimer's Disease

BACKGROUND

Little is known regarding healthcare expenditures for patients with dementia with Lewy bodies (DLB) during the end of life.

OBJECTIVE

This study estimated Medicare expenditures during the last 5 years of life in a decedent sample of patients who were clinically diagnosed with Alzheimer's disease (AD) or DLB and had autopsy confirmed diagnosis.

METHODS

The study included 58 participants clinically diagnosed with mild dementia at study entry (AD: n = 44, DLB: n = 14) and also had autopsy-confirmed diagnoses of pure AD (n = 32), mixed AD+Lewy body (LB) (n = 5), or pure LB (n = 11). Total Medicare expenditures were compared by clinical and pathology confirmed diagnosis, adjusting for sex, age at death, and patient's cognition, function, comorbidities, and psychiatric and extrapyramidal symptoms.

RESULTS

When pathology diagnoses were not considered, predicted annualized total Medicare expenditures during the last 5 years of life were similar between clinically diagnosed AD ($7,465±1,098) and DLB ($7,783±1,803). When clinical diagnoses were not considered, predicted expenditures were substantially higher in patients with pathology confirmed mixed AD+LB ($12,005±2,455) than either pure AD ($6,173±941) or pure LB ($4,629±1,968) cases. Considering clinical and pathology diagnosis together, expenditures for patients with clinical DLB and pathology mixed AD+LB ($23,592±3,679) dwarfed other groups.

CONCLUSION

Medicare expenditures during the last 5 years of life were substantially higher in patients with mixed AD+LB pathology compared to those with pure-AD and pure-LB pathologies, particularly in those clinically diagnosed with DLB. Results highlight the importance of having both clinical and pathology diagnoses in examining healthcare costs.

Pharmacological treatments for psychotic symptoms in dementia: A systematic review with pairwise and network meta-analysis

Psychotic symptoms of dementia are highly prevalent and lead to poor medical outcomes and substantial dysfunction. To date, which drug to use remains controversial without a summary of all direct or indirect comparisons of pharmacotherapy. Therefore, we conducted a systematic review with pairwise and network meta-analysis to examine efficacy and tolerability outcomes of pharmacological treatments in dementia patients. MEDLINE, Cochrane Library, EMBASE, and PubMed were searched systematically up to August 31, 2020. We included trials of cholinesterase inhibitors (ChEIs), memantine, antipsychotics, antidepressants, and mood stabilizers, with final approval from the U.S. Food and Drug Administration. We ranked the comparative effects of all drugs against placebo with surface under the cumulative ranking (SUCRA) probabilities. This analysis is based on 34 trials, which included 10,415 patients randomly assigned to 15 commonly used drug regimens. Donepezil (standardized mean difference [SMD] -0.30, 95% credible interval [CrI] -0.50 to -0.12; SUCRA, 0.85), memantine (SMD -0.20, 95%CrI -0.34 to -0.07; SUCRA, 0.68) and aripiprazole (SMD -0.17, 95% CrI -0.32 to -0.02; SUCRA, 0.62) showed greater benefit than placebo, and with relatively good tolerability in network meta-analyses. Risperidone was also found to be more efficacious than placebo (SMD -0.16, 95% CrI -0.28 to -0.05; SUCRA, 0.60), but with poor tolerability (odds ratios [OR] 1.50, 95% CrI 1.06-2.26). Donepezil, memantine, haloperidol, aripiprazole and risperidone were more efficacious than quetiapine (SMDs ranged from -0.36 to -0.22). Besides, donepezil, memantine and mirtazapine were more efficacious than sertraline (SMDs ranged from -0.47 to -0.36). Most of the results were rated as "low" to "very low". Several effective treatment choices for psychotic symptoms are available across drug classes. Donepezil, memantine and aripiprazole are probably the appropriate options to consider when a pharmacological treatment is indicated. Given the limitations of the meta-analytic approach and the low methodological quality of the majority of studies, our results should be cautiously interpreted.

The Use and Costs of Paid and Unpaid Care for People with Dementia: Longitudinal Findings from the IDEAL Cohort

BACKGROUND

The drivers of costs of care for people with dementia are not well understood and little is known on the costs of care for those with rarer dementias.

OBJECTIVE

To characterize use and costs of paid and unpaid care over time in a cohort of people with dementia living in Britain. To explore the relationship between cohort members' demographic and clinical characteristics and service costs.

METHODS

We calculated costs of health and social services, unpaid care, and out-of-pocket expenditure for people with mild-to-moderate dementia participating in three waves of the IDEAL cohort (2014- 2018). Latent growth curve modelling investigated associations between participants' baseline sociodemographic and diagnostic characteristics and mean weekly service costs.

RESULTS

Data were available on use of paid and unpaid care by 1,537 community-dwelling participants with dementia at Wave 1, 1,199 at Wave 2, and 910 at Wave 3. In models of paid service costs, being female was associated with lower baseline costs and living alone was associated with higher baseline costs. Dementia subtype and caregiver status were associated with variations in baseline costs and the rate of change in costs, which was additionally influenced by age.

CONCLUSION

Lewy body and Parkinson's disease dementias were associated with higher service costs at the outset, and Lewy body and frontotemporal dementias with more steeply increasing costs overall, than Alzheimer's disease. Planners of dementia services should consider the needs of people with these relatively rare dementia subtypes as they may require more resources than people with more prevalent subtypes.

Treatment Efficacy and Acceptabilityof Pharmacotherapies for Dementia with Lewy Bodies: A Systematic Review and Network Meta-Analysis

INTRODUCTION

We investigated the efficacy and acceptability of pharmacotherapy for dementia with Lewy bodies (DLB) while simultaneously considering the neuropsychiatric symptoms (NPS), cognitive function, motor symptoms, and acceptability.

METHODS

Electronic databases were searched from inception through June 5, 2019, for randomized controlled trials (RCTs) and open-label trials (OLTs) in patients with DLB. We performed a pairwise conventional meta-analysis (PWMA) and network meta-analysis (NMA) within a frequentist framework. The main outcomes were mean change scores in NPS, general cognition, motor symptoms and acceptability. The effect sizes and odds ratios with 95% confidence intervals (CIs) were calculated. This study was registered with PROSPERO (CRD42018096996).

RESULTS

In total, we included 29 studies (9 RCTs and 20 OLTs). In the NMA with 9 RCTs, both high- (mean difference [MD] 2.00, 95% CIs, 0.69 to 3.31) and low-dose (1.86, 0.58 to 3.15) donepezil were associated with a greater cognitive improvement than placebo. High-dose zonisamide was associated with greater motor symptom improvement ( -4.10, -7.03 to -1.17]). No medications reached statistical significance regarding improving neuropsychiatric symptoms or developing intolerable adverse effects as compared to placebo. In the second NMA, with 29 studies as an exploratory analysis, aripiprazole and yokukansan may be effective for neuropsychiatric symptoms, while levodopa may be associated with cognitive impairment.

CONCLUSIONS

We report the most comprehensive evidence for the selection of pharmacotherapy for treating different clusters of DLB-related symptoms. Due to the limited availability of RCTs on DLB, more well-conducted RCTs are needed for MMA to warrant clinical efficacy in the future.

An international, randomized, placebo-controlled, phase 2b clinical trial of intepirdine for dementia with Lewy bodies (HEADWAY-DLB)

INTRODUCTION

A phase 2b clinical trial, HEADWAY-DLB, was performed to assess treatment with intepirdine, a serotonin receptor antagonist, in patients with dementia with Lewy bodies (DLB).

METHODS

HEADWAY-DLB was a multinational, double-blind, randomized, placebo-controlled study. Two hundred sixty-nine DLB patients were randomized to receive placebo, 70 mg/day intepirdine, or 35 mg/day intepirdine over 24 weeks. The primary endpoint was change from baseline to week 24 on the Unified Parkinson's Disease Rating Scale-Part III (UPDRS-III).

RESULTS

Both intepirdine groups did not demonstrate significant benefits over placebo at 24 weeks on the UPDRS-III (35 mg/day: P = .1580, 70 mg/day: P = .6069). All other endpoints were not significant. Intepirdine was well tolerated, with a slightly higher incidence of gastrointestinal adverse events observed in the intepirdine groups versus placebo.

DISCUSSION

Intepirdine treatment did not lead to improvements over placebo in patients with DLB. As one of the largest DLB studies to date, HEADWAY-DLB demonstrates that international trials for DLB are feasible within a reasonable timeframe.

Exploring the experiences of living with Lewy body dementia: An integrative review

AIM

Lewy body dementia is a common neurodegenerative dementia with unique challenges in managing day-to-day life. A more in-depth multifaceted picture of the Lewy body dementia lived experience will enable identification of best practice and future research direction. The review aim was to explore experiences of people living with Lewy body dementia and their family carers.

DESIGN

Integrative review method informed by Whittemore and Knafl, supported by the information retrieval framework PALETTE. A convergent integrated approach enabled synthesis of key findings and theme identification.

DATA SOURCES

Medline, CINAHL, PsycINFO, AMED, and ALOIS databases were systematically searched to find studies published between 1995 and 2020.

REVIEW METHODS

Twenty-six articles from twenty studies were synthesized (from 1583 retrieved). Quality and relevance were appraised using the Mixed-Methods Appraisal Tool and Gough's 'Weight of Evidence' framework. Data management was supported by ATLAS.ti 8 and COVIDENCE software.

RESULTS

Four themes were identified: living with an uncertain diagnosis and prognosis; fear of the now - worry for the future; living with behavioural and psychiatric symptoms; and maintaining a social and emotional life. People reported difficulty finding information and support around diagnosis, disease progression and managing complex symptoms. The result is increased caregiver burden, grief and stress and reduced quality of life.

CONCLUSION

Delayed diagnosis and complex symptom burden means people are not getting the timely support and information they need to live and die well. Current evidence is largely quantitative, with a focus on family caregiver burden and unmet need. The challenge remains in how to capture a more holistic picture of the lived experience for people living with Lewy body dementia and those who care for them.

IMPACT

This review highlighted current knowledge and identified gaps in exploring the lived experience for people with Lewy body dementia and their families.

Treatment Options for Dementia with Lewy Bodies: A Network Meta-Analysis of Randomised Control Trials

INTRODUCTION

Dementia with Lewy bodies (DLB) is the third most common type of dementia after Alzheimer's disease (AD) and vascular dementia. Treatment is targeted at specific disease manifestations/symptoms. While donepezil is approved for the treatment of DLB in Japan, to date no other treatment has been approved for this indication anywhere in the world. Notwithstanding, many of the medications that are approved for AD are widely used in the treatment of DLB with varying degrees of success. Consequently, clinical evidence is limited, and there is a need to understand the comparative efficacy and safety of currently used therapies for DLB. The aim of this study was to conduct a network meta-analysis (NMA) to evaluate the outcomes of the available treatment options based on currently used trial endpoints.

METHODS

Using data from a previously published systematic review, we conducted an NMA to investigate the efficacy and safety of treatments in patients with DLB. Networks were based on change from baseline of efficacy endpoints (Mini-Mental State Examination; Neuropsychiatric Inventory; Unified Parkinson's Disease Rating Scale) and rate of safety events (overall adverse events [AEs]; discontinuations; discontinuations due to AEs; psychiatric events).

RESULTS

Focused around a common treatment option of placebo, the NMA comprised studies on donepezil, rivastigmine, memantine and quetiapine. Donepezil 3 mg, 5 mg and 10 mg doses were compared against each other and placebo. Overall, donepezil consistently performed better than the alternative treatments when compared to placebo for all efficacy and safety endpoints. However, the small sample size and/or heterogeneity of the studies led to uncertainty, resulting in no statistically significant differences favouring any treatment above another or placebo.

CONCLUSION

Despite the lack of statistical significance, when assessing the efficacy and safety outcomes for each drug in the evidence network, donepezil appeared to have a more favourable overall benefit/risk profile for patients with DLB. Further comparative trials are required to improve understanding of the true difference between existing and potential future treatment options.

[Practical aspects of using donepezil in the treatment of dementia]

Donepezil is the most commonly used drug of the group of cholinesterase inhibitors. It is recommended for tretament of Alzheimer's disease. Donepezil is also used to treat dementia in Lewy body disease, Parkinson's disease with dementia, and vascular dementia. In Russia, donepezil is not used as often, which is facilitated by the concern of doctors about the possibility of serious side-effects. Clinical studies demonstrate the safety and good tolerability of donepezil. Our study included 62 patients with dementia due to various neurodegenerative diseases (Alzheimer's disease, Lewy body disease, Parkinson's disease with dementia). Thirty-seven patients (59.7%) started to receive donepezil. Side-effects, including bradycardia, hypertension, aggressive behavior, increased tremor, were observed in 7 patients (18.9%). There was no correlation between the development of side-effects and polymorphisms of the CYP2D6 and MDR1 genes.

Pharmacological management of dementia with Lewy bodies with a focus on zonisamide for treating parkinsonism

INTRODUCTION

Dementia with Lewy bodies (DLB) has no approved symptomatic or disease-modifying treatments in the US and Europe, despite being the second most common cause of neurodegenerative dementia.

AREAS COVERED

Herein, the authors briefly review the DLB drug development pipeline, providing a summary of the current pharmacological intervention studies. They then focus on the anticonvulsant zonisamide, a benzisoxazole derivative with a sulfonamide group and look at its value for treating parkinsonism in DLB.

EXPERT OPINION

Several new compounds are being tested in DLB, the most innovative being those aimed at decreasing brain accumulation of α-synuclein. Unfortunately, new drug testing is challenging in terms of consistent diagnostic criteria and lack of reliable biomarkers. Few randomized controlled trials (RCTs) are well-designed, with enough power to detect significant drug effects. Levodopa monotherapy can treat the parkinsonism in DLB, but it can cause agitation or visual hallucination worsening. Two Phase II/III RCTs of DLB patients recently reported a statistically significant improvement in motor function in those receiving zonisamide as an adjunctive treatment to levodopa. New biomarker strategies and validated outcome measures for DLB or prodromal DLB may enhance clinical trial design for the development of specific disease-modifying treatments.

Pharmacogenomics of Cognitive Dysfunction and Neuropsychiatric Disorders in Dementia

Symptomatic interventions for patients with dementia involve anti-dementia drugs to improve cognition, psychotropic drugs for the treatment of behavioral disorders (BDs), and different categories of drugs for concomitant disorders. Demented patients may take >6-10 drugs/day with the consequent risk for drug-drug interactions and adverse drug reactions (ADRs >80%) which accelerate cognitive decline. The pharmacoepigenetic machinery is integrated by pathogenic, mechanistic, metabolic, transporter, and pleiotropic genes redundantly and promiscuously regulated by epigenetic mechanisms. CYP2D6, CYP2C9, CYP2C19, and CYP3A4/5 geno-phenotypes are involved in the metabolism of over 90% of drugs currently used in patients with dementia, and only 20% of the population is an extensive metabolizer for this tetragenic cluster. ADRs associated with anti-dementia drugs, antipsychotics, antidepressants, anxiolytics, hypnotics, sedatives, and antiepileptic drugs can be minimized by means of pharmacogenetic screening prior to treatment. These drugs are substrates, inhibitors, or inducers of 58, 37, and 42 enzyme/protein gene products, respectively, and are transported by 40 different protein transporters. APOE is the reference gene in most pharmacogenetic studies. APOE-3 carriers are the best responders and APOE-4 carriers are the worst responders; likewise, CYP2D6-normal metabolizers are the best responders and CYP2D6-poor metabolizers are the worst responders. The incorporation of pharmacogenomic strategies for a personalized treatment in dementia is an effective option to optimize limited therapeutic resources and to reduce unwanted side-effects.

Cytochrome P450 (CYP450) Interactions Involving Atypical Antipsychotics are Common in Community-Dwelling Older Adults Treated for Behavioral and Psychological Symptoms of Dementia

Treatment of behavioral and psychological symptoms of dementia (BPSD) and comorbidities often necessitates the concomitant use of antipsychotics and non-antipsychotic drugs, thereby potentiating the risk for drug–drug interactions (DDIs). The primary objective of our study was to identify potentially clinically relevant cytochrome P450 (CYP)-mediated DDIs involving antipsychotics among participants enrolled in the Program of All-Inclusive Care for the Elderly (PACE) with BPSD. Additionally, we wanted to determine the prevalence of antipsychotic use in this population. The study included 10,001 PACE participants. The practice setting used a proprietary clinical decision support system (CDSS) to analyze simultaneous multidrug interactions. A retrospective analysis of pharmacy claims data was conducted to identify DDIs involving antipsychotics prescribed for BPSD, using snapshots of medication profiles paired with the CDSS. Of the participants who met inclusion criteria, 1190 (11.9%) were prescribed an antipsychotic; of those, 1071 (90.0%) were prescribed an atypical antipsychotic. Aripiprazole commonly caused (being a perpetrator drug 94.6% of the time) potential DDIs with antidepressants (e.g., duloxetine, venlafaxine, mirtazapine), opioids (e.g., hydrocodone, oxycodone, tramadol) and metoprolol via the CYP2D6 isoform. Risperidone commonly caused (85.7%) potential DDIs with donepezil, lamotrigine and trazodone via the CYP3A4 isoform. Quetiapine exclusively suffered (100%) from potential DDIs with amlodipine, buspirone, omeprazole or topiramate via the CYP3A4 isoform. Antipsychotics are commonly prescribed to PACE participants for BPSD treatment and they may interact with other drugs used to treat comorbidities. A thorough review of concomitant medications will help mitigate the likelihood of potentially dangerous CYP-mediated DDIs involving antipsychotics.