ARIA in patients treated with lecanemab (BAN2401) in a phase 2 study in early Alzheimer's disease

Altered Clearance and Amyloid-Related Imaging Abnormalities

Amyloid-related imaging abnormalities (ARIA) are parenchymal edema/effusion and hemorrhage that occur as side effects of immunotherapies targeting beta-amyloid for patients with Alzheimer's disease (AD). The mechanism of ARIA remains unclear but is thought to be due to loss of vascular integrity secondary to overwhelming perivascular clearance pathways, worsening of cerebral amyloid angiopathy (CAA), removal of amyloid from the vessel wall, and initiation of a local immune response. Further imaging and neuropathological studies may help further inform the mechanism of ARIA and its relationship to underlying AD and CAA pathology.

Allogeneic mesenchymal stem cell therapy with laromestrocel in mild Alzheimer's disease: a randomized controlled phase 2a trial

Alzheimer's disease (AD) is characterized by progressive cognitive decline, severe brain atrophy and neuroinflammation. We conducted a randomized, double-blind, placebo-controlled, parallel-group phase 2a clinical trial that tested the safety and efficacy of laromestrocel, a bone-marrow-derived, allogeneic mesenchymal stem-cell therapy, in slowing AD clinical progression, atrophy and neuroinflammation. Participants across ten centers in the United States were randomly assigned 1:1:1:1 to four infusion groups: group 1 (placebo; four monthly infusions, n = 12); group 2 (25 million cells, one infusion followed by three monthly infusions of placebo, n = 13); group 3 (25 million cells; four monthly doses, n = 13); and group 4 (100 million cells; four monthly doses, n = 11). The study met its primary end point of safety; the rate of treatment-emergent serious adverse events within 4 weeks of any infusion was similar in all four groups: group 1, 0% (95% CI 0-26.5%); group 2, 7.7% (95% CI 0.2-36%); group 3, 7.7% (95% CI 0.2-36%) and group 4, 9.1% (95% CI 0.2-41.3%). Additionally, there were no reported infusion-related reactions, hypersensitivities or amyloid-related imaging abnormalities. Laromestrocel improved clinical assessments at 39 weeks compared to placebo, as measured by a composite AD score (secondary end point was met: group 2 versus placebo change: 0.38; 95% CI -0.06-0.82), Montreal cognitive assessment and the Alzheimer's Disease Cooperative Study Activities of Daily Living. At 39 weeks, Laromestrocel slowed the decline of whole brain volume compared to placebo (n = 10) by 48.4% for all treatment groups combined (groups 2-4: P = 0.005; n = 32) and left hippocampal volume by 61.9% (groups 2-4, P = 0.021; n = 32), and reduced neuroinflammation as measured by diffusion tensor imaging. The change in bilateral hippocampal atrophy correlated with the change in mini-mental state exam scores (R = 0.41, P = 0.0075) in all study patients (N = 42). Collectively these results support safety of single and multiple doses of laromestrocel treatment for mild AD and provide indications of efficacy in combating decline of brain volume and potentially cognitive function. Larger-scale clinical trials of laromestrocel in AD are warranted. ClinicalTrials.gov registration: NCT05233774 .

Conference report: Trends, new technologies and implications for dementia diagnostics, treatment and care in Switzerland

Dementia diseases represent a major burden for the directly affected people, their relatives and modern society. Despite considerable efforts in recent years, early and accurate disease diagnosis and monitoring is still a challenge while no cure is available in most cases. New drugs, in particular disease-modifying therapies, and recent technological advancements offer promising perspectives. The integration of novel biomarkers, artificial intelligence and digital health tools has the potential to transform dementia care, making it more personalised, efficient and adapted to the living conditions and needs of older people. In November 2023, the 7th Dementia Summit convened a panel of experts from geriatrics, neurology, neuropsychology, psychiatry, ethics as well as general medicine to discuss interdisciplinary challenges, advancements and their implications for the future of dementia care in Switzerland. The conference underscored the importance of a multidisciplinary approach to successfully integrate new technologies in both clinical-translational research and dementia prevention, diagnosis and care. While recent innovations represent major steps forward, their implementation also comes with important challenges including questions on healthcare system preparedness and adaptation, ethical aspects, technology literacy, acceptance and appropriate use.

Vaccines for Alzheimer's disease: a brief scoping review

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder and the most common cause of dementia among older adults. Existing treatments-such as cholinesterase inhibitors, N-methyl-D-aspartate receptor antagonists, and monoclonal antibodies targeting amyloid beta-can improve functional and neuropsychiatric outcomes but fail to prevent disease onset, halt progression, or adequately reduce amyloid-beta burden. Consequently, research efforts have shifted to primary prevention through immunization, although the efficacy of these strategies remains uncertain. This review explores the efficacy, safety, and adverse events of current immunotherapies for AD and discusses future research and clinical implications.

METHODS

A scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-SR) checklist. A systematic search was carried out using PubMed, Scopus, and Web of Science.

RESULTS

A total of 145 studies were included. Preclinical research often employed transgenic mouse models to investigate AD pathology and vaccine benefits, while Phase I and II clinical trials centered on safety and preliminary efficacy in humans. Most studies were conducted in the USA, China, and Japan, highlighting these countries' strong clinical trial infrastructure. Vaccination frequently reduced amyloid-beta or tau pathology in preclinical settings, although cognitive outcomes were inconsistent. Clinical trials primarily focused on safety and immune response, with newer vaccines such as ABvac40 demonstrating encouraging results and minimal adverse events.

CONCLUSION

Although AD vaccines show promise in preclinical settings, longer and more comprehensive clinical trials are necessary to determine their long-term efficacy and safety. Standardized protocols and efforts to reduce regional disparities in research would facilitate better comparability and generalizability of findings, thereby guiding the future development of effective immunotherapies for Alzheimer's disease.

Amyloid-Related Imaging Abnormalities With Donanemab in Early Symptomatic Alzheimer Disease: Secondary Analysis of the TRAILBLAZER-ALZ and ALZ 2 Randomized Clinical Trials

Importance

Amyloid-related imaging abnormalities (ARIA) are the major adverse event associated with amyloid-targeting immunotherapy. Identifying clinical features and individual risk factors for ARIA could facilitate effective prediction and prevention strategies.

Objective

To characterize ARIA in participants treated with donanemab.

Design, Setting, and Participants

These prespecified and post hoc exploratory analyses use data from the placebo-controlled portions of the TRAILBLAZER-ALZ and ALZ 2 randomized clinical trials, conducted from December 2017 to December 2020 and from June 2020 to April 2023, respectively. Additional analyses are included from a stand-alone open-label addendum conducted from August 2021 through August 2023. Participants in the placebo-controlled trials and the open-label addendum aged 60 to 85 years with early symptomatic Alzheimer disease and elevated amyloid levels were included. The placebo-controlled trials, but not the addendum, had tau inclusion criteria.

Interventions

Placebo-controlled trial participants were randomized 1:1 to receive placebo or donanemab, and all open-label participants received donanemab. Donanemab was administered every 4 weeks for up to 72 weeks.

Main Outcomes and Measures

The primary outcomes were the frequency, radiographic severity, seriousness, symptoms, timing relative to donanemab treatment, and risk factors for ARIA.

Results

Across 3030 total participants (placebo-controlled trials: 999 placebo participants, 984 donanemab participants; open-label addendum: 1047 donanemab participants), mean (SD) age was approximately 73.7 (6.0) years and 1684 participants (55.6%) were female. Frequencies of ARIA-edema/effusions (ARIA-E) and ARIA-microhemorrhages and hemosiderin deposition (ARIA-H) were higher with donanemab (24.4% and 31.3% in placebo-controlled trials, respectively; 19.8% and 27.2% in open-label addendum, respectively) than with placebo (1.9% and 13.0%, respectively). ARIA-E was mostly mild or moderate in severity. Serious ARIA-E was reported in 1.5% and symptomatic ARIA-E in 5.8% of donanemab-treated participants in the placebo-controlled trials. Symptoms most frequently reported with ARIA-E were headache and confusional state. In 58.3% of donanemab-treated participants with ARIA-E, the first event occurred by the third infusion (approximately month 3). Risk analysis demonstrated independent associations between ARIA-E and 6 baseline variables, including increased risk with APOE ε4 allele number, greater number of microhemorrhages, presence of cortical superficial siderosis, higher amyloid plaque, and elevated mean arterial pressure, and decreased risk with antihypertensive use.

Conclusions and Relevance

ARIA is an adverse event associated with donanemab treatment that requires safety monitoring. Individual ARIA risk can be assessed by APOE ε4 status and baseline imaging findings.

Trial Registrations

ClinicalTrials.gov Identifiers: NCT03367403 and NCT04437511.

Is it time for a paradigm shift? Inclusion of APOE on genetic dyslipidemia panels

APOE codes for apolipoprotein E (ApoE), which plays an important role in lipid and lipoprotein metabolism and homeostasis of tissue lipid content. Several variants in APOE have been associated with inherited dyslipidemias, and a subsequent increased risk of developing premature coronary artery disease (CAD). However, these variants and their impact on risk can be thought of on a spectrum, with some being more monogenic in nature, and others contributing in a polygenic/multifactorial manner. Despite these known associations, there is often hesitancy around ordering APOE genetic testing due to the association with Alzheimer's disease. This paper aims to catalyze discussion around APOE testing and counseling strategies, highlight the nuances around this topic, and advocate for inclusion of APOE testing on dyslipidemia panels when an inherited dyslipidemia is suspected.

Ellagic Acid: A Green Multi-Target Weapon That Reduces Oxidative Stress and Inflammation to Prevent and Improve the Condition of Alzheimer's Disease

Oxidative stress (OS), generated by the overrun of reactive species of oxygen and nitrogen (RONS), is the key cause of several human diseases. With inflammation, OS is responsible for the onset and development of clinical signs and the pathological hallmarks of Alzheimer's disease (AD). AD is a multifactorial chronic neurodegenerative syndrome indicated by a form of progressive dementia associated with aging. While one-target drugs only soften its symptoms while generating drug resistance, multi-target polyphenols from fruits and vegetables, such as ellagitannins (ETs), ellagic acid (EA), and urolithins (UROs), having potent antioxidant and radical scavenging effects capable of counteracting OS, could be new green options to treat human degenerative diseases, thus representing hopeful alternatives and/or adjuvants to one-target drugs to ameliorate AD. Unfortunately, in vivo ETs are not absorbed, while providing mainly ellagic acid (EA), which, due to its trivial water-solubility and first-pass effect, metabolizes in the intestine to yield UROs, or irreversible binding to cellular DNA and proteins, which have very low bioavailability, thus failing as a therapeutic in vivo. Currently, only UROs have confirmed the beneficial effect demonstrated in vitro by reaching tissues to the extent necessary for therapeutic outcomes. Unfortunately, upon the administration of food rich in ETs or ETs and EA, URO formation is affected by extreme interindividual variability that renders them unreliable as novel clinically usable drugs. Significant attention has therefore been paid specifically to multitarget EA, which is incessantly investigated as such or nanotechnologically manipulated to be a potential "lead compound" with protective action toward AD. An overview of the multi-factorial and multi-target aspects that characterize AD and polyphenol activity, respectively, as well as the traditional and/or innovative clinical treatments available to treat AD, constitutes the opening of this work. Upon focus on the pathophysiology of OS and on EA's chemical features and mechanisms leading to its antioxidant activity, an all-around updated analysis of the current EA-rich foods and EA involvement in the field of AD is provided. The possible clinical usage of EA to treat AD is discussed, reporting results of its applications in vitro, in vivo, and during clinical trials. A critical view of the need for more extensive use of the most rapid diagnostic methods to detect AD from its early symptoms is also included in this work.

Phase 2A Proof-of-Concept Double-Blind, Randomized, Placebo-Controlled Trial of Nicotinamide in Early Alzheimer Disease

BACKGROUND AND OBJECTIVES

Nicotinamide is a coenzyme involved in cellular oxidation-reduction reactions that can inhibit Class III histone deacetylases (HDACs) or sirtuins. HDAC inhibition can affect numerous therapeutic pathways, including tau phosphorylation. We tested the hypothesis that nicotinamide treatment could reduce tau phosphorylation in early Alzheimer disease (AD).

METHODS

We performed a randomized, placebo-controlled, phase 2a proof-of-concept trial to evaluate the safety and tolerability of 48 weeks of treatment with 1,500 mg of nicotinamide twice a day. The primary outcome was level of tau phosphorylated at threonine 231 (p-tau231) in CSF. Prespecified secondary outcomes were levels of p-tau181, total tau, amyloid β40 (Aβ40), and Aβ42 in CSF and the clinical measures Alzheimer's Disease Assessment Scale (ADAS-cog13), Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale-Mild Cognitive Impairment (ADCS-ADL-MCI), and Clinical Dementia Rating Summary of Boxes (CDR-SB). Participants were recruited at 2 academic clinical centers. Enrollment criteria included diagnosis of mild cognitive impairment or mild dementia with CSF biomarker confirmation of AD. The Holm-Bonferroni procedure was used to control type I error within biomarker and clinical domains.

RESULTS

Of 47 participants enrolled (mean age = 73.8 years; 43% female), 1 dropped out before treatment initiation and 6 before completion, including 2 in the nicotinamide and 4 in the placebo arm. Adverse events (AEs) were balanced by arm, with few attributed to treatment. Common AEs included infections and nervous system disorders. There was no statistically significant benefit of nicotinamide on the primary outcome of week 48 change from baseline in CSF p-tau231 (analysis of covariance; estimated mean difference in change between arms = -2.06, SE = 4.03; p = 0.61), with observed mean decline in CSF p-tau231 greater in the nicotinamide arm (-4.7 ± 14.5) than in the placebo arm (-2.3 ± 10.6). No significant effects of treatment were observed on secondary biomarker outcomes (CSF p-tau181, Aβ40, Aβ42, and total tau) in similar models (all p values >0.05), with observed mean changes in CSF p-tau181 (0.4 ± 29.8 vs 10.4 ± 41.8) and total tau (8.4 ± 228.6 vs 60.5 ± 237.5) favoring nicotinamide compared with placebo. At week 48, nicotinamide-treated participants experienced less decline on CDR-SB (mixed-effect model with repeated measures; estimate = -1.42, SE = 0.65; p = 0.03 unadjusted for multiple comparisons), without significant differences in cognitive (ADAS-cog; estimate = -1.93, SE = 1.93; p = 0.32) or functional (ADCS-ADL-MCI; estimate = -3.10, SE = 1.86; p = 0.10) outcomes.

DISCUSSION

Nicotinamide was safe but did not alter AD biomarkers.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in patients with MCI or mild dementia with positive CSF AD biomarkers, 48 weeks of nicotinamide, 3,000 mg daily, is no better than placebo in reducing CSF p-tau231.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov: NCT03061474.

Long term rescue of Alzheimer's deficits in vivo by one-time gene-editing of App C-terminus

Gene-editing technologies promise to create a new class of therapeutics that can achieve permanent correction with a single intervention. Besides eliminating mutant alleles in familial disease, gene-editing can also be used to favorably manipulate upstream pathophysiologic events and alter disease-course in wider patient populations, but few such feasible therapeutic avenues have been reported. Here we use CRISPR-Cas9 to edit the last exon of amyloid precursor protein (App), relevant for Alzheimer's disease (AD). Our strategy effectively eliminates an endocytic (YENPTY) motif at APP C-terminus, while preserving the N-terminus and compensatory APP-homologues. This manipulation favorably alters events along the amyloid-pathway - inhibiting toxic APP-β-cleavage fragments (including Aβ) and upregulating neuroprotective APP-α-cleavage products. AAV-driven editing ameliorates neuropathologic, electrophysiologic, and behavioral deficits in an AD knockin mouse model. Effects persist for many months, and no abnormalities are seen in WT mice even after germline App-editing; underlining overall efficacy and safety. Pathologic alterations in the glial-transcriptome of App-KI mice, as seen by single nuclei RNA-sequencing (sNuc-Seq), are also normalized by App C-terminus editing. Our strategy takes advantage of innate transcriptional rules that render terminal exons insensitive to nonsense-decay, and the upstream manipulation is expected to be effective for all forms of AD. These studies offer a path for a one-time disease-modifying treatment for AD.

Amyloid-Related Imaging Abnormalities (ARIA) in Clinical Trials of Gantenerumab in Early Alzheimer Disease

Importance

Data from 2 phase 3 studies of gantenerumab, GRADUATE I/II, and their open-label extensions represent a resource to further characterize amyloid-related imaging abnormalities (ARIA), including long-term sequelae.

Objectives

To describe the characteristics of ARIA and risk factors and clinical consequences of ARIA-edema (ARIA-E).

Design, Setting, and Participants

Secondary data collection from the GRADUATE I/II phase 3 randomized, double-blind, placebo-controlled, 116-week parallel-group studies and their open-label extensions, including PostGraduate, with up to 210 (mean, 125) weeks of total gantenerumab treatment were conducted between 2018 and 2023. The study included multicenter trials at 288 sites across 30 countries. GRADUATE I/II enrolled 985 and 980 participants, respectively, with early symptomatic Alzheimer disease (AD) and amyloid-beta (Aβ) pathology who were aged 50 to 90 years. PostGraduate enrolled 1382 participants (671 previously randomized to gantenerumab). Data were analyzed from November 2, 2022, to October 10, 2023.

Interventions

GRADUATE I/II participants were randomized 1:1 to gantenerumab or placebo. Nine-month uptitration was used to mitigate ARIA risk.

Main outcomes and measures

Postbaseline safety monitoring, including brain magnetic resonance imaging (MRI) findings, and adverse events and cognitive assessments.

Results

The safety-evaluable MRI population of GRADUATE I/II comprised 1939 participants (mean age, 71.7 years; 1105 female [57.0%]). Severity of AD-related Aβ neuropathology (lower cerebrospinal fluid [CSF] Aβ42, hazard ratio [HR] for CSF Aβ42: 0.4; 95% CI, 0.2-0.7) and comorbid cerebrovascular pathology (Fazekas score: HR, 1.6; 95% CI, 1.3-2.0; total superficial siderosis count: HR, 1.9; 95% CI, 1.3-2.6; total microhemorrhage count: HR, 1.3; 95% CI, 1.0-1.5) may be important baseline risk factors for ARIA-E, in addition to apolipoprotein E (APOE) ε4 status (APOE ε4 heterozygous carrier: HR, 2.0; 95% CI, 1.4-2.8 and APOE ε4 homozygous carrier: HR, 4.7; 95% CI, 3.2-6.7). At the group level, ARIA-E did not impact long-term cognitive and functional performance (relative difference in adjusted means for Clinical Dementia Rating-Sum of Boxes was -9% in pooled GRADUATE analysis at week 116 and when censored at first ARIA-E). While taking gantenerumab, ARIA-E and ARIA-hemosiderin occurred in 24.9% (247 of 993) and 22.9% (227 of 993) participants, respectively; first ARIA-E occurred by week 64 in 86.2% (213 of 247) of participants with ARIA-E. Narratives are provided for all serious symptomatic ARIA-E cases.

Conclusions and Relevance

These results show that in addition to APOE ε4 allele count, severity of Aβ neuropathology and comorbid cerebrovascular pathology may be relevant for clinicians prescribing anti-Aβ monoclonal antibodies for early AD and developing individualized safety monitoring plans. Evaluation of these risk factors in other anti-Aβ monoclonal antibodies is recommended.

Trial registrations

ClinicalTrials.gov Identifiers: NCT03444870, NCT03443973, NCT04374253.

From Lab Bench to Hope: Emerging Gene Therapies in Clinical Trials for Alzheimer's Disease

Alzheimer's disease is a progressive neurodegenerative disorder that affects memory and cognitive abilities, affecting millions of people around the world. Current treatments focus on the management of symptoms, as no effective therapy has been approved to modify the underlying disease process. Gene therapy is a promising approach that can offer disease-modifying treatment for AD, targeting various aspects of the pathophysiology of the disease. This review presents a comprehensive overview of the current state of gene therapy research for AD, with a specific focus on clinical trials and preclinical studies that have used nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), apolipoprotein E2 (APOE2), and human telomerase reverse transcriptase (hTERT) as therapeutic gene therapy approaches. These gene targets have shown potential to alleviate the neuropathology of AD in animal studies and have demonstrated feasibility and safety in non-human primates. Despite the failure of the NGF gene therapy approach in clinical trials, we have reviewed and highlighted the reported findings and evaluations from the trials. Furthermore, the review included the conclusions of postmortem brain tissue analysis of AD patients who received NGF gene therapy. The goal is to learn from the failed trials and improve the approach in the future. Although gene therapy shows promise, it faces several challenges and limitations, including optimizing gene delivery methods, enhancing safety and efficacy profiles, and determining long-term results. This review contributes to the growing body of literature on innovative treatments for AD and highlights the need for more research and development to advance gene therapy as a viable treatment option for AD.

Vascular Neurology Considerations for Antiamyloid Immunotherapy: A Science Advisory From the American Heart Association

Antibodies directed at the amyloid-β peptide offer the prospect of disease-modifying therapy for early-stage Alzheimer disease but also carry the risk of brain edema or bleeding events, collectively designated amyloid-related imaging abnormalities. Introduction of the antiamyloid immunotherapies into practice is therefore likely to present a new set of questions for clinicians treating patients with cerebrovascular disease: Which manifestations of cerebrovascular disease should preclude, or permit, antibody treatment? Is it safe to prescribe amyloid immunotherapies to individuals who require antithrombotic treatment, or to administer thrombolysis to antibody-treated individuals with acute stroke? How should severe amyloid-related imaging abnormalities be managed? This science advisory summarizes the data and key considerations to guide these challenging decisions as the medical community collects further data and experience with these groundbreaking agents.

Inhibiting the Cholesterol Storage Enzyme ACAT1/SOAT1 in Aging Apolipoprotein E4 Mice Alters Their Brains' Inflammatory Profiles

Aging and apolipoprotein E4 (APOE4) are the two most significant risk factors for late-onset Alzheimer's disease (LOAD). Compared to APOE3, APOE4 disrupts cholesterol homeostasis, increases cholesteryl esters (CEs), and exacerbates neuroinflammation in brain cells, including microglia. Targeting CEs and neuroinflammation could be a novel strategy to ameliorate APOE4-dependent phenotypes. Toll-like receptor 4 (TLR4) is a key macromolecule in inflammation, and its regulation is associated with the cholesterol content of lipid rafts in cell membranes. We previously demonstrated that in normal microglia expressing APOE3, inhibiting the cholesterol storage enzyme acyl-CoA:cholesterol acyltransferase 1 (ACAT1/SOAT1) reduces CEs, dampened neuroinflammation via modulating the fate of TLR4. We also showed that treating myelin debris-loaded normal microglia with ACAT inhibitor F12511 reduced cellular CEs and activated ABC transporter 1 (ABCA1) for cholesterol efflux. This study found that treating primary microglia expressing APOE4 with F12511 also reduces CEs, activates ABCA1, and dampens LPS-dependent NFκB activation. In vivo, two-week injections of nanoparticle F12511, which consists of DSPE-PEG2000, phosphatidylcholine, and F12511, to aged female APOE4 mice reduced TLR4 protein content and decreased proinflammatory cytokines, including IL-1β in mice brains. Overall, our work suggests nanoparticle F12511 is a novel agent to ameliorate LOAD.

Population pharmacokinetics and exposure-response analyses of safety (ARIA-E and isolated ARIA-H) of lecanemab in subjects with early Alzheimer's disease

Lecanemab (Leqembi®) was recently approved by health authorities in the United States, Japan, and China to treat early Alzheimer's disease (AD), including patients with mild cognitive impairment (MCI) or mild dementia due to Alzheimer's disease upon confirmation of amyloid beta pathology. Extensively and sparsely sampled PK profiles from 1619 AD subjects and 21,929 serum lecanemab observations from two phase I, one phase II, and one phase III studies were well characterized using a two-compartment model with first-order elimination. The final PK model quantified covariate effects of body weight and sex on clearance and central volume of distribution, ADA-positive status, and albumin on clearance, and of Japanese ethnicity on central and peripheral volumes of distribution. Exposure to lecanemab was comparable between two lecanemab-manufacturing processes. However, none of the identified covariates in the model had a clinically relevant impact on model-predicted lecanemab Cmax or AUC at steady state following 10 mg/kg bi-weekly. Importantly, age, a well-recognized risk factor for AD, was not found to significantly affect lecanemab PK. The incidence of ARIA-E as a function of lecanemab exposure was modeled using a logit function with data pooled from 2641 subjects from the phase II and phase III studies, in which a total of 177 incidences of ARIA-E were observed. The probability of ARIA-E was significantly correlated with model-predicted Cmax and predicted to be higher in subjects homozygous for APOE4. The incidence of isolated ARIA-H was not associated with lecanemab exposure and was similar between placebo and lecanemab-treated subjects.

Profiling aducanumab as a treatment option for Alzheimer's disease: an overview of efficacy, safety and tolerability

INTRODUCTION

Alzheimer's disease is the most common form of dementia worldwide. Aducanumab, a monoclonal antibody targeting amyloid-beta, became the first disease-modifying treatment for mild cognitive impairment due to Alzheimer's disease (AD) and mild AD dementia and suggested that removing amyloid from the brain, especially in early AD, might make a difference in slowing cognitive decline.

AREAS COVERED

In this review, the authors outline aducanumab's clinical efficacy as shown through key clinical trials and discuss its approval by the Food and Drug Administration under the accelerated pathway, which sparked both hope and controversy. We also discuss the importance of amyloid-related imaging abnormalities as a major side effect of aducanumab and all subsequent monoclonal antibodies targeting amyloid-beta.

EXPERT OPINION

Aducanumab, became the first monoclonal antibody that provided at least partial support for the amyloid hypothesis by demonstrating slowed cognitive decline by removing amyloid from the brain, although full FDA approval now seems unlikely due to discontinuation of its development. Its introduction raised awareness of ARIA, highlighted the significant costs and need for informed consent in treatment, and emphasized the importance of long-term, diverse, and combination therapy data for future AD treatments targeting amyloid and tau.

Inhibiting the cholesterol storage enzyme ACAT1/SOAT1 in aging Apolipoprotein E4 mice alter their brains inflammatory profiles

Aging and Apolipoprotein E4 (APOE4) are the two most significant risk factors for late-onset Alzheimer's disease (LOAD). Compared to APOE3, APOE4 disrupts cholesterol homeostasis, increases cholesteryl esters (CEs), and exacerbates neuroinflammation in brain cells including microglia. Targeting CEs and neuroinflammation could be a novel strategy to ameliorate APOE4 dependent phenotypes. Toll-like receptor 4 (TLR4) is a key player in inflammation, its regulation is associated with cholesterol content of lipid rafts in cell membranes. We previously demonstrated that in normal microglia expressing APOE3, inhibiting the cholesterol storage enzyme acylCoA:cholesterol acyltransferase 1 (ACAT1/SOAT1) reduces CEs, dampened neuroinflammation via modulating the fate of TLR4. We also showed that treating myelin debris-loaded normal microglia with ACAT inhibitor F12511 reduced cellular CEs and activated ABC transporter 1 (ABCA1) for cholesterol efflux. In this study, we found that treating primary microglia expressing APOE4 with F12511 also reduces CEs, activated ABCA1, and dampened LPS dependent NFkB activation. In vivo, a two-week injections of nanoparticle F12511, which consists of DSPE-PEG 2000 , phosphatidylcholine, and F12511, to aged female APOE4 mice reduced TLR4 protein content and decreased proinflammatory cytokines including IL-1β in APOE4 mice brains. Overall, our work suggests nanoparticle F12511 is a novel agent to ameliorate LOAD.

Intrathecal Immunoselective Nanopheresis for Alzheimer's Disease: What and How? Why and When?

Nanotechnology is transforming therapeutics for brain disorders, especially in developing drug delivery systems. Intrathecal immunoselective nanopheresis with soluble monoclonal antibodies represents an innovative approach in the realm of drug delivery systems for Central Nervous System conditions, especially for targeting soluble beta-amyloid in Alzheimer's disease. This review delves into the concept of intrathecal immunoselective nanopheresis. It provides an overall description of devices to perform this technique while discussing the nanotechnology behind its mechanism of action, its potential advantages, and clinical implications. By exploring current research and advancements, we aim to provide a comprehensive understanding of this novel method, addressing the critical questions of what it is, how it works, why it is needed, and when it should be applied. Special attention is given to patient selection and the optimal timing for therapy initiation in Alzheimer's, coinciding with the peak accumulation of amyloid oligomers in the early stages. Potential limitations and alternative targets beyond beta-amyloid and future perspectives for immunoselective nanopheresis are also described.

Sex-dependent APOE4 neutrophil-microglia interactions drive cognitive impairment in Alzheimer's disease

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD), with increased odds ratios in female carriers. Targeting amyloid plaques shows modest improvement in male non-APOE4 carriers. Leveraging single-cell transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female carriers with AD, we identify a new subset of neutrophils interacting with microglia associated with cognitive impairment. This phenotype is defined by increased interleukin (IL)-17 and IL-1 coexpressed gene modules in blood neutrophils and in microglia of cognitively impaired female APOE ε4 carriers, showing increased infiltration to the AD brain. APOE4 female IL-17+ neutrophils upregulated the immunosuppressive cytokines IL-10 and TGFβ and immune checkpoints, including LAG3 and PD-1, associated with accelerated immune aging. Deletion of APOE4 in neutrophils reduced this immunosuppressive phenotype and restored the microglial response to neurodegeneration, limiting plaque pathology in AD mice. Mechanistically, IL-17F upregulated in APOE4 neutrophils interacts with microglial IL-17RA to suppress the induction of the neurodegenerative phenotype, and blocking this axis supported cognitive improvement in AD mice. These findings provide a translational basis to target IL-17F in APOE ε4 female carriers with cognitive impairment.

Lecanemab: A Humanized Monoclonal Antibody for the Treatment of Early Alzheimer Disease

OBJECTIVE

To review current pharmacology, pharmacokinetics/pharmacodynamics, safety, and efficacy of lecanemab in patients with Alzheimer disease.

DATA SOURCES

A literature search of PubMed (April 1, 2016-November 15, 2023) and ClinicalTrials.gov search were conducted using the following search terms: lecanemab and BAN2401. Additional articles were identified by hand from references.

STUDY SELECTION AND DATA EXTRACTION

We included English-language clinical trials, randomized controlled trials, reviews, and systematic reviews evaluating lecanemab pharmacology, efficacy, or safety in humans for the management of Alzheimer disease.

DATA SYNTHESIS

In the Clarity AD phase III trial, lecanemab led to a decrease in brain amyloid levels and showed moderate improvement in clinical measures of cognition and function. At 18 months, lecanemab 10 mg/kg biweekly exhibited a lower least squares mean change from baseline (1.21) compared to placebo (1.66) of Clinical Dementia Rating-Sum of Boxes score, signifying a significant difference of -0.45 (95% CI, -0.67 to -0.23; P < 0.001). In a subset of 698 participants, lecanemab reduced brain amyloid burden by -59.1 Centiloids (95% CI, -62.6 to -55.6). Lecanemab demonstrated favorable differences in Alzheimer Disease Assessment Scale-cognitive subscale 14, Alzheimer Disease Composite Score, and Alzheimer Disease Cooperative Study-Mild Cognitive Impairment-Activities of Daily Living scores. Adverse events included infusion-related reactions (26.4%) and amyloid-related imaging abnormalities (12.6%).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Lecanemab reduces cognitive decline but raises concerns about intravenous administration, cost, and magnetic resonance imaging needs. Ongoing trials exploring subcutaneous dosing and positron emission tomography scans may offer solutions.

CONCLUSION

Lecanemab is a humanized monoclonal antibody that is selective for soluble amyloid-beta (Aβ) aggregates. Lecanemab has exhibited a decrease in brain Aβ plaques and moderately less decline on clinical measures of cognitive function.

Regional Variability in MRI Scans with Different Magnetic Field Strengths in Japan: Implications for Healthcare Preparedness for Alzheimer's Disease Treatment

(1) Background: The 2023 approval of lecanemab for early-stage Alzheimer's disease (AD) highlighted the need for routine 1.5T or 3.0T MRI scans to monitor amyloid-related imaging abnormalities (ARIAs). Regional disparities in MRI scan frequency, MRI scanner availability, and scanner magnetic field strengths could affect readiness for anti-amyloid therapy and lead to inconsistencies in ARIA detection nationwide. (2) Methods: We assessed regional variance in MRI scan frequency and field strength across Japan using the National Database (NDB) Open Data website, which summarizes Japanese public health insurance claims from the fiscal years (FYs) 2015 to 2021. We employed a mixed-effects model with prefecture-level random intercepts and slopes over time, subsequently categorizing prefectures into clusters based on MRI usage. (3) Results: 1.5T MRI was the most common magnetic field strength, remaining stable from FY2015 to FY2021. 3.0T MRI usage slightly increased, although the COVID-19 pandemic in FY2020 led to a maximum reduction of 5%. Prefecture-level variance was higher for 3.0T MRIs, with more frequent usage in western Japan. (4) Conclusions: This study highlights prefecture-level variance in MRI usage across Japan. The insights gained could be instrumental in improving healthcare preparedness for anti-amyloid treatment and patient management.

The efficacy and safety of lecanemab 10 mg/kg biweekly compared to a placebo in patients with Alzheimer's disease: a systematic review and meta-analysis of randomized controlled trials

Alzheimer's disease, prevalent in individuals aged 60 and above, constitutes most dementia cases and significantly impairs memory and cognitive functions. With global Alzheimer's cases projected to triple by 2050, there is a pressing need for effective interventions. Lecanemab, a monoclonal antibody targeting amyloid-beta plaques, shows promise in slowing Alzheimer's progression. Positive clinical trial results have instilled hope in patients, prompting ongoing research to advance understanding and intervention possibilities. To contribute to this knowledge base, we conducted a systematic review and meta-analysis, focusing on lecanemab's efficacy and safety at a dosage of 10 mg/kg. This comprehensive approach aimed to address gaps in the current literature, scrutinize research disparities, and guide future investigations. Applying strict inclusion/exclusion criteria, we assessed study details, participant information, and intervention specifics, using the Cochrane risk of bias tool for quality evaluation. Statistical analyses, conducted with R software, included risk ratios and mean differences, assessing heterogeneity and publication bias. The meta-analysis reveals a significant positive effect of lecanemab (10 mg/kg biweekly) on cognitive outcomes in Alzheimer's disease. Consistent reductions in ADCOMS, CDR-SB, and ADAS-cog14 scores across studies indicate drug efficacy with narrow confidence intervals and no significant heterogeneity. While TEAE shows no significant difference, heightened risks of ARIA-E and ARIA-H associated with lecanemab underscore the need for vigilant safety monitoring in clinical practice. Despite the drug efficacy, the study emphasizes a balanced assessment of benefits and potential risks associated with lecanemab, providing critical insights for clinicians evaluating its use in addressing cognitive impairment in individuals with Alzheimer's disease.

Amyloid-related imaging abnormalities (ARIA): diagnosis, management, and care in the setting of amyloid-modifying therapy

Amyloid-related imaging abnormalities, were originally described by dementia care experts. The wider use of aducanumab and now lecanemab warrant broader understanding by the health care provider continuum. The optimal care approach for patients with Alzheimer's dementia, treated with amyloid-targeted therapy, includes proper clinical diagnosis, complication surveillance, specific imaging protocols, expert specialty consultation, integrated treatment strategies, and proper facility system planning. Improved awareness and understanding of amyloid-modifying therapy, both benefits and potential complications, among the health care provider continuum is paramount to the success of complex care programs. Specifically, recognition of treatment high risk, high benefit groups, and the interface of concurrent antiplatelet and anticoagulation. This integrated acute, specialty, and primary care approach should improve patient care quality and outcome.

New plasma LC-MS/MS assays for the quantitation of beta-amyloid peptides and identification of apolipoprotein E proteoforms for Alzheimer's disease risk assessment

Early detection of Alzheimer's disease (AD) represents an unmet clinical need. Beta-amyloid (Aβ) plays an important role in AD pathology, and the Aβ42/40 peptide ratio is a good indicator for amyloid deposition. In addition, variants of the apolipoprotein E (APOE) gene are associated with variable AD risk. Here, we describe the development and validation of high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays for plasma Aβ40 and Aβ42 quantitation, as well as apolipoprotein E (ApoE) proteotype determination as a surrogate for APOE genotype. Aβ40 and Aβ42 were simultaneously immunoprecipitated from plasma, proteolytically digested, and quantitated by LC-MS/MS. ApoE proteotype status was qualitatively assessed by targeting tryptic peptides from the ApoE2, ApoE3, and ApoE4 proteoforms. Both assays were validated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Within-run precision was 1.8%-4.2% (Aβ40), 1.9%-7.2% (Aβ42), and 2.6%-8.3% (Aβ42/40 ratio). Between-run precision was 3.5%-5.9% (Aβ40), 3.8%-8.0% (Aβ42), and 3.3%-8.7% (Aβ42/40 ratio). Both Aβ40 and Aβ42 were linear from 10 to 2500 pg/mL. Identified ApoE proteotypes had 100% concordance with APOE genotypes. We have developed a precise, accurate, and sensitive high-throughput LC-MS/MS assay for plasma Aβ40, Aβ42, and proteoforms of ApoE.

Passive Anti-Amyloid Beta Immunotherapies in Alzheimer's Disease: From Mechanisms to Therapeutic Impact

Alzheimer's disease, the most common type of dementia worldwide, lacks effective disease-modifying therapies despite significant research efforts. Passive anti-amyloid immunotherapies represent a promising avenue for Alzheimer's disease treatment by targeting the amyloid-beta peptide, a key pathological hallmark of the disease. This approach utilizes monoclonal antibodies designed to specifically bind amyloid beta, facilitating its clearance from the brain. This review offers an original and critical analysis of anti-amyloid immunotherapies by exploring several aspects. Firstly, the mechanisms of action of these therapies are reviewed, focusing on their ability to promote Aβ degradation and enhance its efflux from the central nervous system. Subsequently, the extensive history of clinical trials involving anti-amyloid antibodies is presented, from initial efforts using first-generation molecules leading to mixed results to recent clinically approved drugs. Along with undeniable progress, the authors also highlight the pitfalls of this approach to offer a balanced perspective on this topic. Finally, based on its potential and limitations, the future directions of this promising therapeutic strategy for Alzheimer's disease are emphasized.

Updated safety results from phase 3 lecanemab study in early Alzheimer's disease

BACKGROUND

Alzheimer disease (AD) is a major health problem of aging, with tremendous burden on healthcare systems, patients, and families globally. Lecanemab, an FDA-approved amyloid beta (Aβ)-directed antibody indicated for the treatment of early AD, binds with high affinity to soluble Aβ protofibrils, which have been shown to be more toxic to neurons than monomers or insoluble fibrils. Lecanemab has been shown to be well tolerated in multiple clinical trials, although risks include an increased rate of amyloid-related imaging abnormalities (ARIA) and infusion reactions relative to placebo.

METHODS

Clarity AD was an 18-month treatment (Core study), multicenter, double-blind, placebo-controlled, parallel-group study with open-label extension (OLE) in participants with early AD. Eligible participants were randomized 1:1 across 2 treatment groups (placebo and lecanemab 10 mg/kg biweekly). Safety evaluations included monitoring of vital signs, physical examinations, adverse events, clinical laboratory parameters, and 12-lead electrocardiograms. ARIA occurrence was monitored throughout the study by magnetic resonance imaging, read both locally and centrally.

RESULTS

Overall, 1795 participants from Core and 1612 participants with at least one dose of lecanemab (Core + OLE) were included. Lecanemab was generally well-tolerated in Clarity AD, with no deaths related to lecanemab in the Core study. There were 9 deaths during the OLE, with 4 deemed possibly related to study treatment. Of the 24 deaths in Core + OLE, 3 were due to intracerebral hemorrhage (ICH): 1 placebo in the Core due to ICH, and 2 lecanemab in OLE with concurrent ICH (1 on tissue plasminogen activator and 1 on anticoagulant therapy). In the Core + OLE, the most common adverse events in the lecanemab group (> 10%) were infusion-related reactions (24.5%), ARIA with hemosiderin deposits (ARIA-H) microhemorrhages (16.0%), COVID-19 (14.7%), ARIA with edema (ARIA-E; 13.6%), and headache (10.3%). ARIA-E and ARIA-H were largely radiographically mild-to-moderate. ARIA-E generally occurred within 3-6 months of treatment, was more common in ApoE e4 carriers (16.8%) and most common in ApoE ε4 homozygous participants (34.5%).

CONCLUSIONS

Lecanemab was generally well-tolerated, with the most common adverse events being infusion-related reactions, ARIA-H, ARIA-E. Clinicians, participants, and caregivers should understand the incidence, monitoring, and management of these events for optimal patient care.

TRIAL REGISTRATION

ClinicalTrials.gov numbers: Clarity AD NCT03887455).

Effects of Serious Games in Older Adults With Mild Cognitive Impairment

OBJECTIVE

The rising prevalence of mild cognitive impairment (MCI) has spurred interest in innovative cognitive rehabilitation approaches, including serious games. This review summarizes randomized clinical trials (RCTs) exploring the impact of serious games on MCI patients.

METHODS

We conducted a comprehensive data search using key terms such as "gamification," "digital therapy," "cognition," "mild cognitive impairment," and "Alzheimer's disease." We exclusively considered published RCTs, excluding animal studies and basic research.

RESULTS

We identified eight RCTs. Four RCTs examined the effects of serious games using cognitive training for MCI patients. Notably, one study found that non-specific training (Nintendo Wii) significantly enhanced cognitive function and quality of life compared to cognition-specific computer training (CoTras). Among the remaining three RCTs, one specifically demonstrated that personalized serious game-based cognitive training yielded superior cognitive outcomes and reduced depressive symptoms. One RCT focused on serious games incorporating physical exercise, highlighting the effectiveness of kinetic-based exergaming in enhancing overall cognition. Three RCT focused on combined cognitive training and physical exercise. A double-blind RCT revealed that progressive resistance training or standalone physical exercise outperformed the combined approach in improving executive function and global cognition. Two additional RCTs reported positive outcomes, including improvements in cognitive function and electroencephalogram patterns associated with game-based interventions.

CONCLUSION

Serious games, whether focusing on cognitive training, physical exercise, or a combination of both, have potential to improve cognitive and functional outcomes in individuals with MCI. Further research and standardization of protocols are needed to better understand the full potential of serious games in MCI.

Potential impact of unblinding on observed treatment effects in Alzheimer's disease trials

INTRODUCTION

Adverse effects of monoclonal antibodies against amyloid beta are common, and may affect validity of randomized controlled trials (RCTs) through unblinding of participants.

METHODS

We used observations from published phase 3 RCTs in Alzheimer's disease to calculate the magnitude of unblinding effects on cognition that would be required to explain observed cognitive benefits in RCTs.

RESULTS

In trials of lecanemab, aducanumab, and donanemab, incidence of amyloid-related imaging abnormalities with active treatment ranged from 22% to 44%, the vast majority of which presumably led to unblinding. Effects of unblinding on the Clinical Dementia Rating Sum of Boxes required to fully explain observed drug effects ranged from 1.1 point (95% confidence interval: 0.2-2.0) with aducanumab, to 3.3 points (2.1-4.4) with donanemab and 3.7 points (2.0-5.6) with lecanemab. Infusion-related reactions were common, with potential unblinding effects particularly for lecanemab. Similar patterns were observed for the Alzheimer's Disease Assessment Scale Cognitive subscale.

DISCUSSION

Psychological treatment effects due to unblinding may explain a substantial share of observed treatment effects in RCTs.

Blood levels of glial fibrillary acidic protein for predicting clinical progression to Alzheimer's disease in adults without dementia: a systematic review and meta-analysis protocol

BACKGROUND

There is urgent clinical need to identify reliable prognostic biomarkers that predict the progression of dementia symptoms in individuals with early-phase Alzheimer's disease (AD) especially given the research on and predicted applications of amyloid-beta (Aβ)-directed immunotherapies to remove Aβ from the brain. Cross-sectional studies have reported higher levels of cerebrospinal fluid and blood glial fibrillary acidic protein (GFAP) in individuals with AD-associated dementia than in cognitively unimpaired individuals. Further, recent longitudinal studies have assessed the prognostic potential of baseline blood GFAP levels as a predictor of future cognitive decline in cognitively unimpaired individuals and in those with mild cognitive impairment (MCI) due to AD. In this systematic review and meta-analysis, we propose analyzing longitudinal studies on blood GFAP levels to predict future cognitive decline.

METHODS

This study will include prospective and retrospective cohort studies that assessed blood GFAP levels as a prognostic factor and any prediction models that incorporated blood GFAP levels in cognitively unimpaired individuals or those with MCI. The primary outcome will be conversion to MCI or AD in cognitively unimpaired individuals or conversion to AD in individuals with MCI. Articles from PubMed and Embase will be extracted up to December 31, 2023, without language restrictions. An independent dual screening of abstracts and potentially eligible full-text reports will be conducted. Data will be dual-extracted using the CHeck list for critical appraisal, data extraction for systematic Reviews of prediction Modeling Studies (CHARMS)-prognostic factor, and CHARMS checklists, and we will dual-rate the risk of bias and applicability using the Quality In Prognosis Studies and Prediction Study Risk-of-Bias Assessment tools. We will qualitatively synthesize the study data, participants, index biomarkers, predictive model characteristics, and clinical outcomes. If appropriate, random-effects meta-analyses will be performed to obtain summary estimates. Finally, we will assess the body of evidence using the Grading of Recommendation, Assessment, Development, and Evaluation Approach.

DISCUSSION

This systematic review and meta-analysis will comprehensively evaluate and synthesize existing evidence on blood GFAP levels for prognosticating presymptomatic individuals and those with MCI to help advance risk-stratified treatment strategies for early-phase AD.

TRIAL REGISTRATION

PROSPERO CRD42023481200.

The Impact of Anti-Amyloid Immunotherapies on Stroke Care

Anti-amyloid immunotherapies have recently emerged as treatments for Alzheimer's disease. While these therapies have demonstrated efficacy in clearing amyloid-β and slowing cognitive decline, they have also been associated with amyloid-related imaging abnormalities (ARIA) which include both edema (ARIA-E) and hemorrhage (ARIA-H). Given that ARIA have been associated with significant morbidity in cases of antithrombotic or thrombolytic therapy, an understanding of mechanisms of and risk factors for ARIA is of critical importance for stroke care. We discuss the latest data regarding mechanisms of ARIA, including the role of underlying cerebral amyloid angiopathy, and implications for ischemic stroke prevention and management.

Cell type-specific roles of APOE4 in Alzheimer disease

The ɛ4 allele of the apolipoprotein E gene (APOE), which translates to the APOE4 isoform, is the strongest genetic risk factor for late-onset Alzheimer disease (AD). Within the CNS, APOE is produced by a variety of cell types under different conditions, posing a challenge for studying its roles in AD pathogenesis. However, through powerful advances in research tools and the use of novel cell culture and animal models, researchers have recently begun to study the roles of APOE4 in AD in a cell type-specific manner and at a deeper and more mechanistic level than ever before. In particular, cutting-edge omics studies have enabled APOE4 to be studied at the single-cell level and have allowed the identification of critical APOE4 effects in AD-vulnerable cellular subtypes. Through these studies, it has become evident that APOE4 produced in various types of CNS cell - including astrocytes, neurons, microglia, oligodendrocytes and vascular cells - has diverse roles in AD pathogenesis. Here, we review these scientific advances and propose a cell type-specific APOE4 cascade model of AD. In this model, neuronal APOE4 emerges as a crucial pathological initiator and driver of AD pathogenesis, instigating glial responses and, ultimately, neurodegeneration. In addition, we provide perspectives on future directions for APOE4 research and related therapeutic developments in the context of AD.

Risk factors in developing amyloid related imaging abnormalities (ARIA) and clinical implications

Alzheimer's disease (AD) affects over 6 million people over the age of 65. The advent of new anti-amyloid monoclonal antibodies as treatment for early Alzheimer's disease these immunotherapeutics may slow disease progression but also pose significant risks. Amyloid related imaging abnormalities (ARIA) identified on MRI following administration of these new monoclonal antibodies can cause both brain edema (ARIA-E) and hemorrhage (ARIA-H). While most ARIA is asymptomatic, some patients can develop headache, confusion, nausea, dizziness, seizures and in rare cases death. By analyzing lecanemab, aducanumab, gantenerumab, donanemab, and bapineuzumab clinical trials; risk factors for developing ARIA can be identified to mitigate some of the ARIA risk. Risk factors for developing ARIA-E are a positive Apoε4 carrier status and prior multiple cerebral microhemorrhages. Risk factors for ARIA-H are age, antithrombotic use, and history of prior strokes. With lecanemab, ARIA-E and ARIA-H were seen at lower rates 12 and 17%, respectively, compared to aducanumab (ARIA-E 35% and ARIA-H 19%) in treated patients. ARIA risk factors have impacted inclusion and exclusion criteria, determining who can receive lecanemab. In some clinics, almost 90% of Alzheimer's patients are excluded from receiving these new anti-amyloid therapeutics. This review aims to discuss risk factors of ARIA and highlight important areas for further research. With more anti-amyloid monoclonal antibodies approved by the Food and Drug Administration, considering patient risk factors for developing ARIA is important to identify to minimize patient's risk while receiving these new therapies.

APOE-ε4 allele[s]-associated adverse events reported from placebo arm in clinical trials for Alzheimer's disease: implications for anti-amyloid beta therapy

APOE-ε4 allele[s] is a risk factor for Alzheimer's disease (AD) and Amyloid-Related Imaging Abnormalities (ARIA) in anti-amyloid beta therapy, and is also associated with cerebrovascular risk factors such as hyperlipidemia or atherosclerosis. During AD clinical trials, APOE-ε4 carriers may experience neuropsychiatric adverse events (AEs) related to these risks, complicating the differentiation of ARIA from cerebrovascular events based on symptoms. This study aimed to examine the hypothetical impact of considering the APOE-ε4 allele's risk for non-ARIA AEs during AD clinical trials. We used data from the Critical Path for Alzheimer's Disease (CPAD) from the placebo arm of randomized controlled trials (RCT) for AD treatment. We determined whether AEs were reported more frequently in APOE-ε4 carriers, quantifying with reporting odds ratio (ROR) using a mixed effect model. We also evaluated the association between ROR levels and the prior probability that an AE is symptomatic ARIA. We analyzed 6,313 patients with AD or mild cognitive impairment in 28 trials. Of the prespecified 35 neuropsychiatric or related AEs, several had a significantly high ROR: "delusion" (ROR = 4.133), "confusional state" (ROR = 1.419), "muscle spasms" (ROR = 9.849), "irritability" (ROR = 12.62), "sleep disorder" (ROR = 2.944), or "convulsion" (ROR = 13.00). However, none remained significant after adjusting for Mini-Mental State Examination scores. There is no strong evidence to suggest that specific neuropsychiatric AEs occur more frequently without drug treatment association among APOE-ε4 carriers. The influence of APOE-ε4 allele[s] on the clinicians' assessment of the likelihood of ARIA during safety monitoring in anti-amyloid beta monoclonal antibody treatment might be unchanged, thus maintaining the current level of awareness of clinicians of AEs.

Adverse Events as a Cause of Unblinding of Allocated Arms in Anti-Amyloid Therapy Trials: A Meta-Analysis of the Predictive Value

Anti-amyloid drugs for early Alzheimer's disease, including lecanemab, are associated with adverse events (AEs), such as amyloid-related imaging abnormalities (ARIA)-edema/effusion (E), ARIA-hemorrhage, and infusion-related reactions, which can indicate allocated arms in clinical trials. Herein, we evaluated the predictive value of AEs using a meta-analysis to estimate their incidence and simulated positive predictive value (PPV). The PPV for ARIA-E was high (0.915), but that for ARIA hemorrhage was low (0.630). Infusion-related reactions had a high PPV of 0.910, but with a wide confidence interval. Our results suggest the need to ameliorate the unblinding effects of AEs, particularly ARIA-E in trials.

Simplifying Alzheimer's Disease Monitoring: A Novel Machine-Learning Approach to Estimate the Clinical Dementia Rating Sum of Box Changes Using the Mini-Mental State Examination and Functional Activities Questionnaire

Background

Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice.

Objective

Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing.

Methods

Baseline data from 944 ADNI and 171 J-ADNI amyloid-positive participants were used to build machine-learning models predicting annualized CDRSB changes between visits, based on MMSE and FAQ scores. Prediction performance was evaluated with mean absolute error (MAE) and R2 comparing predicted to actual rmDeltaCDRSB/rmDeltayear. We further assessed whether decline in cognitive function surpassing particular thresholds could be identified using the predicted rmDeltaCDRSB/rmDeltayear.

RESULTS

The models achieved the minimum required prediction errors (MAE < 1.0) and satisfactory prediction accuracy (R2>0.5) for mild cognitive impairment (MCI) patients for changes in CDRSB over periods of 18 months or longer. Predictions of annualized CDRSB progression>0.5, >1.0, or >1.5 demonstrated a consistent performance (i.e., Matthews correlation coefficient>0.5). These results were largely replicated in the J-ADNI case predictions.

CONCLUSIONS

Our method effectively predicted MCI patient deterioration in the CDRSB based solely on MMSE and FAQ scores. It may aid routine practice for disease-modifying therapy drug efficacy evaluation, without necessitating CDR testing at every visit.

A Comprehensive Review on Potential Molecular Drug Targets for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is an onset and incurable neurodegenerative disorder that has been linked to various genetic, environmental, and lifestyle factors. Recent research has revealed several potential targets for drug development, such as the prevention of Aβ production and removal, prevention of tau hyperphosphorylation, and keeping neurons alive. Drugs that target numerous ADrelated variables have been developed, and early results are encouraging. This review provides a concise map of the different receptor signaling pathways associated with Alzheimer's Disease, as well as insight into drug design based on these pathways. It discusses the molecular mechanisms of AD pathogenesis, such as oxidative stress, aging, Aβ turnover, thiol groups, and mitochondrial activities, and their role in the disease. It also reviews the potential drug targets, in vivo active agents, and docking studies done in AD and provides prospects for future drug development. This review intends to provide more clarity on the molecular processes that occur in Alzheimer's patient's brains, which can be of use in diagnosing and preventing the condition.

NB-02 Protects Neurons and Astrocytes from Oligomeric Amyloid-β-Mediated Damage

Alzheimer's disease (AD) is a progressive neurodegenerative disease with limited therapeutic strategies. NB-02 is a novel botanical drug that has shown promise as a protective and therapeutic treatment for AD in an APP/PS1 preclinical mouse model. In this paper, we investigate the underlying mechanisms by which NB-02 provides these therapeutic advantages using in vitro neuron-astrocyte co-cultures. Pretreatment with NB-02 prevented pathological calcium elevations in neurons and astrocytes after application of toxic soluble amyloid-β (Aβ) oligomers. NB-02 also prevented cell death associated with the addition of soluble Aβ oligomers suggesting NB-02 is effective at protecting both neurons and astrocytes from Aβ-mediated damage.

Initial Experience with Lecanemab and Lessons Learned in 71 Patients in a Regional Medical Center

BACKGROUND AND OBJECTIVES

On July 6, 2023 the U.S. Food and Drug Administration approved the anti-amyloid monoclonal antibody lecanemab (Leqembi®) for treatment of patients with mild cognitive impairment or mild dementia due to Alzheimer's disease (AD). Our early experience and lessons learned with lecanemab in a regional community medical center are described.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective observational study highlights the first 71 patients treated with lecanemab at our multidisciplinary Norton Neuroscience Institute Memory Center. All patients had positive cerebrospinal fluid biomarkers for AD and underwent at least 1 lecanemab infusion. Two patients had additional amyloid PET scans which were positive.

RESULTS

The mean age was 72 years (49-90 years), and 44 (62%) patients were female. Most were Caucasian (68 [96%]), and 54 [76%] were referred to our Memory Center by their primary care provider. Comorbidities were common, including hypertension (34 [48%]), hypercholesterolemia (51 [72%]), diabetes mellitus (17 [24%]), and cardiovascular disease excluding hypertension (22 [31%]). The mean body mass index was 27.0 (range: 17.8-45.0). A total of 36 (51%) patients were heterozygous for the ApoE4 genotype, and 9 (13%) were homozygous. A total of 61 [86%] patients had been treated with donepezil; 40 (56%) patients had received memantine. Of the 50 patients who completed 1 or more safety monitoring brain MRIs following infusion, 12 (24%) had amyloid-related imaging abnormalities (ARIA) detected: solitary ARIA-H (hemorrhage) in 5, solitary ARIA-E (edema) in 3, and both ARIA-H and ARIA-E in 4. Of the 12 patients with ARIA, 9 were asymptomatic, 4 were homozygous for the ApoE4 genotype, and 6 were heterozygous for the ApoE4 genotype. Of the 9 who were homozygous for the ApoE4 genotype in this study, 4 (44%) had evidence of ARIA. Of the 36 who were heterozygous for the ApoE4 genotype, 6 (17%) were diagnosed with ARIA. Twenty-six (37%) patients experienced infusion reactions after their first lecanemab infusion: headaches (12 patients) and shaking/chills/rigors (11 patients) were most common. Twenty-three (88%) of these 26 patients reported the side effects either at the infusion center or within the first 24 hours post-infusion. One patient died shortly after the first lecanemab infusion of a myocardial infarction. It is uncertain whether or not this death was related to lecanemab treatment.

CONCLUSION

Through our early experience with lecanemab, we have recognized several areas of improvement which have clarified and enhanced the lecanemab infusion experience.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Alzheimer's Disease-Related Proteins Targeted by Secondary Metabolite Compounds from Streptomyces: A Scoping Review

Background

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized as rapid and progressive cognitive decline affecting 26 million people worldwide. Although immunotherapies are ideal, its clinical safety and effectiveness are controversial, hence, treatments are still reliant on symptomatic medications. Concurrently, the Streptomyces genus has attracted attention given its pharmaceutically beneficial secondary metabolites to treat neurodegenerative diseases.

Objective

To present secondary metabolites from Streptomyces sp. with regulatory effects on proteins and identified prospective target proteins for AD treatment.

Methods

Research articles published between 2010 and 2021 were collected from five databases and 83 relevant research articles were identified. Post-screening, only 12 research articles on AD-related proteins were selected for further review. Bioinformatics analyses were performed through the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) network, PANTHER Go-Slim classification system (PANTHER17.0), and Kyoto Encyclopedia of Genes and Genomes (KEGG) Mapper.

Results

A total of 20 target proteins were identified from the 12 shortlisted articles. Amyloid-β, BACE1, Nrf-2, Beclin-1, and ATG5 were identified as the potential target proteins, given their role in initiating AD, mitigating neuroinflammation, and autophagy. Besides, 10 compounds from Streptomyces sp., including rapamycin, alborixin, enterocin, bonnevillamides D and E, caniferolide A, anhydroexfoliamycin, rhizolutin, streptocyclinone A and B, were identified to exhibit considerable regulatory effects on these target proteins.

Conclusions

The review highlights several prospective target proteins that can be regulated through treatments with Streptomyces sp. compounds to prevent AD's early stages and progression. Further identification of Streptomyces sp. compounds with potential anti-AD properties is recommended.

Cancer drugs with high repositioning potential for Alzheimer's disease

INTRODUCTION

Despite the recent full FDA approval of lecanemab, there is currently no disease modifying therapy (DMT) that can efficiently slow down the progression of Alzheimer's disease (AD) in the general population. This statement emphasizes the need to identify novel DMTs in the shortest time possible to prevent a global epidemic of AD cases as the world population experiences an increase in lifespan.

AREAS COVERED

Here, we review several classes of anti-cancer drugs that have been or are being investigated in Phase II/III clinical trials for AD, including immunomodulatory drugs, RXR agonists, sex hormone therapies, tyrosine kinase inhibitors, and monoclonal antibodies.

EXPERT OPINION

Given the overall course of brain pathologies during the progression of AD, we express a great enthusiasm for the repositioning of anti-cancer drugs as possible AD DMTs. We anticipate an increasing number of combinatorial therapy strategies to tackle AD symptoms and their underlying pathologies. However, we strongly encourage improvements in clinical trial study designs to better assess target engagement and possible efficacy over sufficient periods of drug exposure.

Alzheimer's Targeted Treatments: Focus on Amyloid and Inflammation

Alzheimer's disease (AD) is the major cause of dementia that is now threatening the lives of billions of elderly people on the globe, and recent progress in the elucidation of the pathomechanism of AD is now opening venue to tackle the disease by developing and implementing "disease-modifying therapies" that directly act on the pathophysiology and slow down the progression of neurodegeneration. A recent example is the success of clinical trials of anti-amyloid b antibody drugs, whereas other therapeutic targets, e.g., inflammation and tau, are being actively investigated. In this dual perspective session, we plan to have speakers from leading pharmas in the field representing distinct investments in the AD space, which will be followed by the comment from scientific leadership of the Alzheimer's Association who will speak on behalf of all stakeholders. Neuroscientists participating in the Society for Neuroscience may be able to gain insights into the cutting edge of the therapeutic approaches to AD and neurodegenerative disorders, and discuss future contribution of neuroscience to this field.

Anti-Amyloid Therapy, AD, and ARIA: Untangling the Role of CAA

Anti-amyloid therapies (AATs), such as anti-amyloid monoclonal antibodies, are emerging treatments for people with early Alzheimer's disease (AD). AATs target amyloid β plaques in the brain. Amyloid-related imaging abnormalities (ARIA), abnormal signals seen on magnetic resonance imaging (MRI) of the brain in patients with AD, may occur spontaneously but occur more frequently as side effects of AATs. Cerebral amyloid angiopathy (CAA) is a major risk factor for ARIA. Amyloid β plays a key role in the pathogenesis of AD and of CAA. Amyloid β accumulation in the brain parenchyma as plaques is a pathological hallmark of AD, whereas amyloid β accumulation in cerebral vessels leads to CAA. A better understanding of the pathophysiology of ARIA is necessary for early detection of those at highest risk. This could lead to improved risk stratification and the ultimate reduction of symptomatic ARIA. Histopathological confirmation of CAA by brain biopsy or autopsy is the gold standard but is not clinically feasible. MRI is an available in vivo tool for detecting CAA. Cerebrospinal fluid amyloid β level testing and amyloid PET imaging are available but do not offer specificity for CAA vs amyloid plaques in AD. Thus, developing and testing biomarkers as reliable and sensitive screening tools for the presence and severity of CAA is a priority to minimize ARIA complications.

Biomarkers in Alzheimer's disease: role in early and differential diagnosis and recognition of atypical variants

BACKGROUND

Development of in vivo biomarkers has shifted the diagnosis of Alzheimer's disease (AD) from the later dementia stages of disease towards the earlier stages and has introduced the potential for pre-symptomatic diagnosis. The International Working Group recommends that AD diagnosis is restricted in the clinical setting to people with specific AD phenotypes and supportive biomarker findings.

MAIN BODY

In this review, we discuss the phenotypic presentation and use of biomarkers for the early diagnosis of typical and atypical AD and describe how this can support clinical decision making, benefit patient communication, and improve the patient journey. Early diagnosis is essential to optimize the benefits of available and emerging treatments. As atypical presentations of AD often mimic other dementias, differential diagnosis can be challenging and can be facilitated using AD biomarkers. However, AD biomarkers alone are not sufficient to confidently diagnose AD or predict disease progression and should be supplementary to clinical assessment to help inform the diagnosis of AD.

CONCLUSIONS

Use of AD biomarkers with incorporation of atypical AD phenotypes into diagnostic criteria will allow earlier diagnosis of patients with atypical clinical presentations that otherwise would have been misdiagnosed and treated inappropriately. Early diagnosis is essential to guide informed discussion, appropriate care and support, and individualized treatment. It is hoped that disease-modifying treatments will impact the underlying AD pathology; thus, determining the patient's AD phenotype will be a critical factor in guiding the therapeutic approach and the assessment of the effects of interventions.

Guidelines for pharmacotherapy in Alzheimer's disease - A primer on FDA-approved drugs

The growing prevalence of dementia makes it important for us to better understand its pathophysiology and treatment modalities, to improve the quality of life of patients and caregivers. Alzheimer's disease (AD), a neurodegenerative disease, is the most common form of amnestic dementia in the geriatric population. Pathophysiology of AD is widely attributed to aggregation of amyloid-beta (Aβ) plaques and hyperphosphorylation of tau proteins. Initial treatment modalities aimed to increase brain perfusion in a non-specific manner. Subsequent therapy focused on rectifying neurotransmitter imbalance in the brain. Newer drugs modify the progression of the disease by acting against aggregated Aβ plaques. However, not all drugs used in therapy of AD have been granted approval by the United States Food and Drug Administration (FDA). This review categorizes and summarizes the FDA-approved drugs in the treatment of AD in a manner that would make it a convenient reference for researchers and practicing physicians alike. Drugs that mitigate symptoms of dementia may be categorized into mitigators of Behavioral and Psychological Symptoms of Dementia (BPSD), and mitigators of cognitive decline. BPSD mitigators include brexpiprazole, an atypical antipsychotic with a once-daily dosage suited to treat agitation in dementia patients, and suvorexant, an orexin receptor antagonist used to treat sleep disturbances. Cognitive decline mitigators include cholinesterase inhibitors such as donepezil, rivastigmine, and galantamine and glutamate inhibitors such as memantine. Donepezil is the most commonly prescribed drug. It is cheap, well-tolerated, and may be prescribed orally once daily, or as a transdermal patch once weekly. It increases ACh levels, enhances oligodendrocyte differentiation and also protects against Aβ toxicity. However, regular cardiac monitoring is required due to reports of cardiac conduction side effects. Rivastigmine requires a twice-daily oral dosage or once-daily replacement of transdermal patch. It has fewer cardiac side effects than donepezil, but local application-site reactions have been noted. Galantamine, in addition to improving cognitive symptoms in a short span of time, also delays the development of BPSDs and has minimal drug-drug interactions by virtue of having multiple metabolic pathways. However, cardiac conduction disturbances must be closely monitored for. Memantine, a glutamate regulator, acts as an anti-Parkinsonian agent and an antidepressant, in addition to improving cognition and neuroprotection, and requires a once-daily dosage in the form of immediate-release or sustained-release oral tablets. Disease-modifying drugs such as aducanumab and lecanemab reduce the Aβ burden. Both act by binding with fibrillary conformations of Aβ plaques in the brain. These drugs have a risk of causing amyloid-related imaging abnormalities, especially in persons with ApoE4 gene. Aducanumab is administered once every 4 weeks and lecanemab once every 2 weeks. The decision on the choice of the drug must be made after considering the availability of drug, compliance of patient (once-daily vs. multiple doses daily), cost, specific comorbidities, and the risk-benefit ratio for the particular patient. Other non-pharmacological treatment modalities must also be adopted to have a holistic approach toward the treatment of AD.

A possible mechanism for the enhanced toxicity of beta-amyloid protofibrils in Alzheimer's disease

The amyloid-beta peptide (Aβ) is a driver of Alzheimer's disease (AD). Aβ monomers can aggregate and form larger soluble (oligomers/protofibrils) and insoluble (fibrils) forms. There is evidence that Aβ protofibrils are the most toxic form, but the reasons are not known. Consistent with a critical role for this form of Aβ in AD, a recently FDA-approved therapeutic antibody targeted against protofibrils, lecanemab, slows the progression of AD in patients. The plasma contact system, which can promote coagulation and inflammation, has been implicated in AD pathogenesis. This system is activated by Aβ which could lead to vascular and inflammatory pathologies associated with AD. We show here that the contact system is preferentially activated by protofibrils of Aβ. Aβ protofibrils bind to coagulation factor XII and high molecular weight kininogen and accelerate the activation of the system. Furthermore, lecanemab blocks Aβ protofibril activation of the contact system. This work provides a possible mechanism for Aβ protofibril toxicity in AD and why lecanemab is therapeutically effective.