Using Clinical Scales and Digital Measures to Explore Falls in Patients with Lewy Body Dementia

Introduction

PRESENCE was a phase 2 clinical trial assessing the efficacy of mevidalen, a D1 receptor positive allosteric modulator, for symptomatic treatment of Lewy body dementia (LBD). Mevidalen demonstrated improvements in motor and non-motor features of LBD, global functioning, and actigraphy-measured activity and daytime sleep. Adverse events (AEs) of fall were numerically increased in mevidalen-treated participants.

Methods

A subset of PRESENCE participants wore a wrist actigraphy device for 2-week periods pre-, during, and posttreatment. Actigraphy sleep and activity measures were derived per period and analyzed to assess for their association with participants' reports of an AE of fall. Prespecified baseline and treatment-emergent clinical characteristics were also included in the retrospective analysis of falls. Independent-samples t test and χ² test were performed to compare the means and proportions between individuals with/without falls.

Results

A trend toward more falls was observed with mevidalen treatment (31/258 mevidalen-treated vs. 4/86 in placebo-treated participants: p = 0.12). Higher body mass index (BMI) (p < 0.05), more severe disease measured by baseline Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part II (p < 0.05), and a trend toward improved Alzheimer's Disease Assessment Scale-Cognitive Subscale 13 (ADAS-Cog₁₃) (p = 0.06) were associated with individuals with falls. No statistically significant associations with falls and treatment-emergent changes were observed.

Conclusion

The association of falls with worse baseline disease severity and higher BMI and overall trend toward improvements on cognitive and motor scales suggest that falls in PRESENCE may be related to increased activity in mevidalen-treated participants at greater risk for falling. Future studies to confirm this hypothesis using fall diaries and digital assessments are necessary.

Evaluating the Use of Digital Biomarkers to Test Treatment Effects on Cognition and Movement in Patients with Lewy Body Dementia

Background:

PRESENCE was a Phase 2 trial assessing mevidalen for symptomatic treatment of Lewy body dementia (LBD). Participants received daily doses (10, 30, or 75 mg) of mevidalen (LY3154207) or placebo for 12 weeks.

Objective:

To evaluate if frequent cognitive and motor tests using an iPad app and wrist-worn actigraphy to track activity and sleep could detect mevidalen treatment effects in LBD.

Methods:

Of 340 participants enrolled in PRESENCE, 238 wore actigraphy for three 2-week periods: pre-, during, and post-intervention. A subset of participants (n = 160) enrolled in a sub-study using an iPad trial app with 3 tests: digital symbol substitution (DSST), spatial working memory (SWM), and finger-tapping. Compliance was defined as daily test completion or watch-wearing ≥23 h/day. Change from baseline to week 12 (app) or week 8 (actigraphy) was used to assess treatment effects using Mixed Model Repeated Measures analysis. Pearson correlations between sensor-derived features and clinical endpoints were assessed.

Results:

Actigraphy and trial app compliance was > 90% and > 60%, respectively. At baseline, daytime sleep positively correlated with Epworth Sleepiness Scale score (p < 0.01). Physical activity correlated with improvement on Movement Disorder Society –Unified Parkinson Disease Rating Scale (MDS-UPDRS) part II (p < 0.001). Better scores of DSST and SWM correlated with lower Alzheimer Disease Assessment Scale –Cognitive 13-Item Scale (ADAS-Cog₁₃) (p < 0.001). Mevidalen treatment (30 mg) improved SWM (p < 0.01), while dose-dependent decreases in daytime sleep (10 mg: p < 0.01, 30 mg: p < 0.05, 75 mg: p < 0.001), and an increase in walking minutes (75 mg dose: p < 0.001) were observed, returning to baseline post-intervention.

Conclusion:

Devices used in the LBD population achieved adequate compliance and digital metrics detected statistically significant treatment effects.

Safety and Efficacy of Mevidalen in Lewy Body Dementia: A Phase 2, Randomized, Placebo-Controlled Trial

BACKGROUND

Mevidalen is a selective positive allosteric modulator (PAM) of the dopamine D1 receptor subtype.

OBJECTIVE

To assess the safety and efficacy of mevidalen for treatment of cognition in patients with Lewy body dementia (LBD).

METHODS

PRESENCE was a phase 2, 12-week study in participants with LBD (N = 344) randomly assigned (1:1:1:1) to daily doses of mevidalen (10, 30, or 75 mg) or placebo. The primary outcome measure was change from baseline on Cognitive Drug Research Continuity of Attention (CoA) composite score. Secondary outcomes included Alzheimer's Disease Assessment Scale-Cognitive Subscale 13 (ADAS-cog₁₃ ), Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). Numerous safety measures were collected.

RESULTS

Mevidalen failed to meet primary or secondary cognition endpoints. Mevidalen resulted in significant, dose-dependent improvements of MDS-UPDRS total score (sum of Parts I-III, 10 mg P < 0.05, 30 mg P < 0.05, 75 mg P < 0.01, compared to placebo). The 30 mg and 75 mg mevidalen doses significantly improved ADCS-CGIC scores compared to placebo (minimal or better improvement: 30 mg P < 0.01, 75 mg P < 0.01; moderate or better improvement: 30 mg P < 0.05, 75 mg P < 0.001). Increases in blood pressure, adverse events, and cardiovascular serious adverse events were most pronounced at the 75 mg dose.

CONCLUSIONS

Mevidalen harnesses a novel mechanism of action that improves motor symptoms associated with LBD on top of standard of care while improving or not worsening non-motor symptoms associated with traditional dopaminergic therapy. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Lewy Body Dementia Association's Industry Advisory Council: proceedings of the second annual meeting

In 2019, the Lewy Body Dementia Association formed an Industry Advisory Council to bring together a collaborative group of stakeholders with the goal of accelerating clinical research into Lewy body dementia treatments. At the second annual meeting of the Industry Advisory Council, held virtually on June 18, 2020, the key members presented ongoing and planned efforts toward the council’s goals. The meeting also featured a discussion about the effects of the COVID-19 pandemic on Lewy body dementia clinical research, lessons learned from that experience, and how those lessons can be applied to the design and conduct of future clinical trials. This report provides a brief summary of the meeting proceedings with a focus on efforts to improve and adapt future Lewy body dementia clinical research.

Challenges and opportunities for improving the landscape for Lewy body dementia clinical trials

Lewy body dementia (LBD), including dementia with Lewy bodies and Parkinson's disease dementia, affects over a million people in the USA and has a substantial impact on patients, caregivers, and society. Symptomatic treatments for LBD, which can include cognitive, neuropsychiatric, autonomic, sleep, and motor features, are limited with only two drugs (cholinesterase inhibitors) currently approved by regulatory agencies for dementia in LBD. Clinical trials represent a top research priority, but there are many challenges in the development and implementation of trials in LBD. To address these issues and advance the field of clinical trials in the LBDs, the Lewy Body Dementia Association formed an Industry Advisory Council (LBDA IAC), in addition to its Research Center of Excellence program. The LBDA IAC comprises a diverse and collaborative group of experts from academic medical centers, pharmaceutical industries, and the patient advocacy foundation. The inaugural LBDA IAC meeting, held in June 2019, aimed to bring together this group, along with representatives from regulatory agencies, to address the topic of optimizing the landscape of LBD clinical trials. This review highlights the formation of the LBDA IAC, current state of LBD clinical trials, and challenges and opportunities in the field regarding trial design, study populations, diagnostic criteria, and biomarker utilization. Current gaps include a lack of standardized clinical assessment tools and evidence-based management strategies for LBD as well as difficulty and controversy in diagnosing LBD. Challenges in LBD clinical trials include the heterogeneity of LBD pathology and symptomatology, limited understanding of the trajectory of LBD cognitive and core features, absence of LBD-specific outcome measures, and lack of established standardized biologic, imaging, or genetic biomarkers that may inform study design. Demands of study participation (e.g., travel, duration, and frequency of study visits) may also pose challenges and impact trial enrollment, retention, and outcomes. There are opportunities to improve the landscape of LBD clinical trials by harmonizing clinical assessments and biomarkers across cohorts and research studies, developing and validating outcome measures in LBD, engaging the patient community to assess research needs and priorities, and incorporating biomarker and genotype profiling in study design.

Genome-wide association study of rate of cognitive decline in Alzheimer's disease patients identifies novel genes and pathways

INTRODUCTION

Variability exists in the disease trajectories of Alzheimer's disease (AD) patients. We performed a genome-wide association study to examine rate of cognitive decline (ROD) in patients with AD.

METHODS

We tested for interactions between genetic variants and time since diagnosis to predict the ROD of a composite cognitive score in 3946 AD cases and performed pathway analysis on the top genes.

RESULTS

Suggestive associations (P < 1.0 × 10^-6 ) were observed on chromosome 15 in DNA polymerase-γ (rs3176205, P = 1.11 × 10^-7 ), chromosome 7 (rs60465337,P = 4.06 × 10^-7 ) in contactin-associated protein-2, in RP11-384F7.1 on chromosome 3 (rs28853947, P = 5.93 × 10^-7 ), family with sequence similarity 214 member-A on chromosome 15 (rs2899492, P = 5.94 × 10^-7 ), and intergenic regions on chromosomes 16 (rs4949142, P = 4.02 × 10^-7 ) and 4 (rs1304013, P = 7.73 × 10^-7 ). Significant pathways involving neuronal development and function, apoptosis, memory, and inflammation were identified.

DISCUSSION

Pathways related to AD, intelligence, and neurological function determine AD progression, while previously identified AD risk variants, including the apolipoprotein (APOE) ε4 and ε2 variants, do not have a major impact.

Basic Considerations for the Use of Monoclonal Antibodies in Migraine

BACKGROUND

Migraine impacts more than 36 million people in the United States and 1 billion people worldwide. Despite the increasing availability of acute and preventive therapies, there is still tremendous unmet need. Potential treatments in development include monoclonal antibodies (mAbs). Appropriate use of these “biologic” treatments will necessitate an understanding of the aspects that distinguish them from traditional medications.

AIM

Many drug classes are prescribed for migraine treatment, but all have limitations. Recently, calcitonin gene-related peptide (CGRP) activity has shown a significant promise as a target for preventive therapy. In this review, we provide an overview of the potential role of CGRP mAbs in migraine, with a focus on their design, pharmacokinetics, safety, and immunogenicity.

CONCLUSIONS

The CGRP mAbs are an innovative new therapy for migraine and address the need for effective and tolerable preventive options. MAbs, including those that target CGRP or its receptor, bind to a target with high specificity and affinity and lead to few off-target adverse effects, although mechanism-based adverse reactions may occur. Unlike other therapeutic antibodies used to treat neurologic disease, CGRP mAbs do not have a target within the immune system and have been designed to avoid altering the immune system. The safety and efficacy of mAbs against CGRP or its receptors are being investigated in clinical development programs, and the first of these therapies has received regulatory approval in the United States.

Genomic structure and expression of the human serotonin 2A receptor gene (HTR2A) locus: identification of novel HTR2A and antisense (HTR2A-AS1) exons

Background

The serotonin 2A receptor is widely implicated in genetic association studies and remains an important drug target for psychiatric, neurological, and cardiovascular conditions. RNA sequencing redefined the architecture of the serotonin 2A receptor gene (HTR2A), revealing novel mRNA transcript isoforms utilizing unannotated untranslated regions of the gene. Expression of these untranslated regions is modulated by common single nucleotide polymorphisms (SNPs), namely rs6311. Previous studies did not fully capture the complexity of the sense- and antisense-encoded transcripts with respect to novel exons in the HTR2A gene locus. Here, we comprehensively catalogued exons and RNA isoforms for both HTR2A and HTR2A-AS1 using RNA-Seq from human prefrontal cortex and multiple mouse tissues. We subsequently tested associations between expression of newfound gene features and common SNPs in humans.

Results

We find that the human HTR2A gene spans ~66 kilobases and consists of 7, rather than 4 exons. Furthermore, the revised human HTR2A-AS1 gene spans ~474 kilobases and consists of 18, rather than 3 exons. Three HTR2A exons directly overlap with HTR2A-AS1 exons, suggesting potential for complementary nucleotide interactions. The repertoire of possible mouse Htr2a splice isoforms is remarkably similar to humans and we also find evidence for overlapping sense-antisense transcripts in the same relative positions as the human transcripts. rs6311 and SNPs in high linkage disequilibrium are associated with HTR2A-AS1 expression, in addition to previously described associations with expression of the extended 5’ untranslated region of HTR2A.

Conclusions

Our proposed HTR2A and HTR2A-AS1 gene structures dramatically differ from current annotations, now including overlapping exons on the sense and anti-sense strands. We also find orthologous transcript isoforms expressed in mice, providing opportunities to elucidate the biological roles of the human isoforms using a model system. Associations between rs6311 and expression of HTR2A and HTR2A-AS1 suggest this polymorphism is capable of modulating the expression of the sense or antisense transcripts. Still unclear is whether these SNPs act directly on the expression of the sense or antisense transcripts and whether overlapping exons are capable of interacting through complimentary base-pairing. Additional studies are necessary to determine the extent and nature of interactions between the SNPs and the transcripts prior to interpreting these findings in the context of phenotypes associated with HTR2A.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0325-6) contains supplementary material, which is available to authorized users.

Gain and loss of function of P2X7 receptors: mechanisms, pharmacology and relevance to diabetic neuropathic pain

Background

Genetic causes of exaggerated or reduced pain sensitivity in humans are well known. Recently, single nucleotide polymorphisms (SNPs) in the gene P2RX7, coding for the ATP-gated ion channel P2X_7, have been described that cause gain-of-function (GOF) and loss-of-function (LOF), respectively of this channel. Importantly, P2RX7 SNPs have been associated with more or less severe pain scores in patient suffering of post-mastectomy pain and osteoarthritis.

Results

The functional consequences of some P2RX7 SNPs (rs208294 (His155Tyr), rs1718119 (Ala348Thr) and rs3751143 (Glu496Ala)) were studied in recombinant cells in vitro. Our findings suggest a correlation between GOF and LOF of P2X₇ and actual channel protein expression. Both channel and pore function for these mutant P2X₇ receptors changed in parallel to protein levels. On the other hand, the mutant receptors did not differ in their sensitivity to known P2X₇ agonists and antagonists. We further demonstrated that in patients with diabetic peripheral neuropathic pain (DPNP), the presence of the GOF SNPs rs208294 (His155Tyr) and rs1718119 (Ala348Thr) is associated, in females, with higher pain intensity scores.

Conclusions

Our present results confirm the physiological relevance of some of the SNPs in the P2RX7 gene and show that the presence of these genetic variants correlates with pain sensitivity also in a diabetic neuropathic pain patient population.

Genetic analysis of quantitative phenotypes in AD and MCI: imaging, cognition and biomarkers

The Genetics Core of the Alzheimer's Disease Neuroimaging Initiative (ADNI), formally established in 2009, aims to provide resources and facilitate research related to genetic predictors of multidimensional Alzheimer's disease (AD)-related phenotypes. Here, we provide a systematic review of genetic studies published between 2009 and 2012 where either ADNI APOE genotype or genome-wide association study (GWAS) data were used. We review and synthesize ADNI genetic associations with disease status or quantitative disease endophenotypes including structural and functional neuroimaging, fluid biomarker assays, and cognitive performance. We also discuss the diverse analytical strategies used in these studies, including univariate and multivariate analysis, meta-analysis, pathway analysis, and interaction and network analysis. Finally, we perform pathway and network enrichment analyses of these ADNI genetic associations to highlight key mechanisms that may drive disease onset and trajectory. Major ADNI findings included all the top 10 AD genes and several of these (e.g., APOE, BIN1, CLU, CR1, and PICALM) were corroborated by ADNI imaging, fluid and cognitive phenotypes. ADNI imaging genetics studies discovered novel findings (e.g., FRMD6) that were later replicated on different data sets. Several other genes (e.g., APOC1, FTO, GRIN2B, MAGI2, and TOMM40) were associated with multiple ADNI phenotypes, warranting further investigation on other data sets. The broad availability and wide scope of ADNI genetic and phenotypic data has advanced our understanding of the genetic basis of AD and has nominated novel targets for future studies employing next-generation sequencing and convergent multi-omics approaches, and for clinical drug and biomarker development.