Publications by authors named "Pierre N Tariot"

131 Publications

The case for low-level BACE1 inhibition for the prevention of Alzheimer disease.

Nat Rev Neurol 2021 Sep 21. Epub 2021 Sep 21.

German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.

Alzheimer disease (AD) is the most common cause of dementia in older individuals (>65 years) and has a long presymptomatic phase. Preventive therapies for AD are not yet available, and potential disease-modifying therapies targeting amyloid-β plaques in symptomatic stages of AD have only just been approved in the United States. Small-molecule inhibitors of β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1; also known as β-secretase 1) reduce the production of amyloid-β peptide and are among the most advanced drug candidates for AD. However, to date all phase II and phase III clinical trials of BACE inhibitors were either concluded without benefit or discontinued owing to futility or the occurrence of adverse effects. Adverse effects included early, mild cognitive impairment that was associated with all but one inhibitor; preliminary results suggest that the cognitive effects are non-progressive and reversible. These discontinuations have raised questions regarding the suitability of BACE1 as a drug target for AD. In this Perspective, we discuss the status of BACE inhibitors and suggest ways in which the results of the discontinued trials can inform the development of future clinical trials of BACE inhibitors and related secretase modulators as preventative therapies. We also propose a series of experiments that should be performed to inform 'go-no-go' decisions in future trials with BACE inhibitors and consider the possibility that low levels of BACE1 inhibition could avoid adverse effects while achieving efficacy for AD prevention.
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http://dx.doi.org/10.1038/s41582-021-00545-1DOI Listing
September 2021

Sex Differences in Cognitive Abilities Among Children With the Autosomal Dominant Alzheimer Disease Presenilin 1 E280A Variant From a Colombian Cohort.

JAMA Netw Open 2021 Aug 2;4(8):e2121697. Epub 2021 Aug 2.

Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston.

Importance: We previously reported that children with the autosomal dominant Alzheimer disease (ADAD) presenilin 1 (PSEN1) E280A variant had early life plasma biomarker findings consistent with amyloid β overproduction. However, the cognitive functioning of children with this variant has not been characterized vs those without the variant.

Objective: To test whether cognitive functioning of children with and without the PSEN1 E280A variant in the same ADAD cohort differed by genetic status (ie, PSEN1 variant) and sex.

Design, Setting, And Participants: This cohort study was conducted among 1354 children (including 265 children with the variant) aged 6 to 16 years recruited from the Alzheimer Prevention Initiative Colombia Registry. Participants from the city of Medellín and surrounding suburban areas traveled to the University of Antioquia to undergo all procedures. Participants were administered a Spanish version of the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) to measure general cognitive functioning. Data were analyzed from July through November 2020.

Main Outcomes And Measures: Univariate general linear models were used to characterize differences on WISC-IV cognitive performance by genetic status, sex, and the interaction of genetic status with sex. Urbanity, socioeconomic status, and education were entered as covariates.

Results: Among 1354 children with ADAD (695 [51.3%] girls; mean [SD] age, 11.64 [2.64] years), there were 265 children with the variant (19.6%) and 1089 children without the variant (80.4%). Children with and without the variant did not differ by demographic variables or performance on WISC-IV indices. Irrespective of genetic status, boys had statistically significantly decreased mean scores on indices for working memory (90.27 [95% CI, 89.21-91.34] vs 92.99 [95% CI, 91.98-93.99]; mean difference = -2.72; P < .001), perceptual reasoning (91.56 [95% CI, 90.47-92.65] vs. 93.27 [95% CI, 91.23-94.30]; mean difference = -1.71; P = .03), and verbal comprehension (88.69 [95% CI, 87.54-89.84] vs. 90.81 [95% CI, 89.73-91.90]; mean difference = -2.12; P = .009) compared with girls. In the interaction between sex and genetic status, boys with the variant had worse mean working memory index performance (88.78 [95% CI, 86.86-90.70]) than girls with the variant (93.75 [95% CI, 91.95-95.55]; mean difference = -4.97; P = .001), as well as boys (91.77 [95% CI, 90.85-92.70]; mean difference = -2.99; P = .04) and girls (92.22 [95% CI, 91.32-93.13]; mean difference = -3.44; P = .009) without the variant.

Conclusions And Relevance: This study found that boys with the PSEN1 variant had decreased working memory abilities compared with girls with the variant and boys and girls without the variant, suggesting a sex-specific genetic risk in early life cognitive performance among individuals with the PSEN1 variant. This increased risk of future cognitive difficulties among boys with the variant may have important downstream implications for learning and academic achievement and could be associated with sex differences seen in adulthood on episodic memory measures.
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http://dx.doi.org/10.1001/jamanetworkopen.2021.21697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408665PMC
August 2021

Trial of Pimavanserin in Dementia-Related Psychosis.

N Engl J Med 2021 07;385(4):309-319

From Banner Alzheimer's Institute and University of Arizona College of Medicine, Phoenix (P.N.T.); Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada, Las Vegas, Las Vegas (J.L.C.); Gérontopôle Alzheimer Clinical and Research Center, Centre Hospitalier Universitaire de Toulouse, Geriatric Department, Maintain Functions and Intrinsic Capacities with Aging Research Team, Center for Epidemiology and Population Health Research, INSERM, Université Paul Sabatier, Toulouse, France (M.E.S.-M.); University of Exeter School of Medicine, Exeter, United Kingdom (C.B.); the Department of Neurology, Oregon Health and Sciences University, Portland (D.E.-L.); the Department of Psychiatry and Human Behavior and the Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine (D.L.S.), and Acadia Pharmaceuticals, San Diego (B.M., J.M.Y., S.S., E.P.F.) - both in California; the Department of Psychiatry, Columbia University Irving Medical Center, New York (D.P.D.); and Perelman School of Medicine at the University of Pennsylvania, Philadelphia (D.W.).

Background: Patients with dementia due to neurodegenerative disease can have dementia-related psychosis. The effects of the oral 5-HT inverse agonist and antagonist pimavanserin on psychosis related to various causes of dementia are not clear.

Methods: We conducted a phase 3, double-blind, randomized, placebo-controlled discontinuation trial involving patients with psychosis related to Alzheimer's disease, Parkinson's disease dementia, dementia with Lewy bodies, frontotemporal dementia, or vascular dementia. Patients received open-label pimavanserin for 12 weeks. Those who had a reduction from baseline of at least 30% in the score on the Scale for the Assessment of Positive Symptoms-Hallucinations and Delusions (SAPS-H+D, with higher scores indicating greater psychosis) and a Clinical Global Impression-Improvement (CGI-I) score of 1 (very much improved) or 2 (much improved) at weeks 8 and 12 were randomly assigned in a 1:1 ratio to continue receiving pimavanserin or to receive placebo for up to 26 weeks. The primary end point, assessed in a time-to-event analysis, was a relapse of psychosis as defined by any of the following: an increase of at least 30% in the SAPS-H+D score and a CGI-I score of 6 (much worse) or 7 (very much worse), hospitalization for dementia-related psychosis, stopping of the trial regimen or withdrawal from the trial for lack of efficacy, or use of antipsychotic agents for dementia-related psychosis.

Results: Of the 392 patients in the open-label phase, 41 were withdrawn for administrative reasons because the trial was stopped for efficacy; of the remaining 351 patients, 217 (61.8%) had a sustained response, of whom 105 were assigned to receive pimavanserin and 112 to receive placebo. A relapse occurred in 12 of 95 patients (13%) in the pimavanserin group and in 28 of 99 (28%) in the placebo group (hazard ratio, 0.35; 95% confidence interval, 0.17 to 0.73; P = 0.005). During the double-blind phase, adverse events occurred in 43 of 105 patients (41.0%) in the pimavanserin group and in 41 of 112 (36.6%) in the placebo group. Headache, constipation, urinary tract infection, and asymptomatic QT prolongation occurred with pimavanserin.

Conclusions: In a trial that was stopped early for efficacy, patients with dementia-related psychosis who had a response to pimavanserin had a lower risk of relapse with continuation of the drug than with discontinuation. Longer and larger trials are required to determine the effects of pimavanserin in dementia-related psychosis. (Funded by Acadia Pharmaceuticals; HARMONY ClinicalTrials.gov number, NCT03325556.).
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http://dx.doi.org/10.1056/NEJMoa2034634DOI Listing
July 2021

PET evidence of preclinical cerebellar amyloid plaque deposition in autosomal dominant Alzheimer's disease-causing Presenilin-1 E280A mutation carriers.

Neuroimage Clin 2021 4;31:102749. Epub 2021 Jul 4.

Banner Alzheimer's Institute, Phoenix, AZ, USA; Arizona Alzheimer's Consortium, Phoenix, AZ, USA; Arizona State University, Tempe, AZ, USA; University of Arizona, Tucson, AZ, USA; Translational Genomics Research Institute, Phoenix, AZ, USA. Electronic address:

Background: In contrast to sporadic Alzheimer's disease, autosomal dominant Alzheimer's disease (ADAD) is associated with greater neuropathological evidence of cerebellar amyloid plaque (Aβ) deposition. In this study, we used positron emission tomography (PET) measurements of fibrillar Aβ burden to characterize the presence and age at onset of cerebellar Aβ deposition in cognitively unimpaired (CU) Presenilin-1 (PSEN1) E280A mutation carriers from the world's largest extended family with ADAD.

Methods: F florbetapir and C Pittsburgh compound B (PiB) PET data from two independent studies - API ADAD Colombia Trial (NCT01998841) and Colombia-Boston (COLBOS) longitudinal biomarker study were included. The tracers were selected independently by the respective sponsors prior to the start of each study and used exclusively throughout. Template-based cerebellar Aβ-SUVR (standard-uptake value ratios) using a known-to-be-spared pons reference region (cerebellar SUVR_pons), to a) compare 28-56-year-old CU carriers and non-carriers; b) estimate the age at which cerebellar SUVR_pons began to differ significantly in carrier and non-carrier groups; and c) characterize in carriers associations with age, cortical SUVR_pons, delayed recall memory, and API ADAD composite score.

Results: Florbetapir and PiB cerebellar SUVR_pons were significantly higher in carriers than non-carriers (p < 0.0001). Cerebellar SUVR_pons began to distinguish carriers from non-carriers at age 34, 10 years before the carriers' estimated age at mild cognitive impairment onset. Florbetapir and PiB cerebellar SUVR_pons in carriers were positively correlated with age (r = 0.44 & 0.69, p < 0.001), cortical SUVR_pons (r = 0.55 & 0.69, p < 0.001), and negatively correlated with delayed recall memory (r = -0.21 & -0.50, p < 0.05, unadjusted for cortical SUVR_pons) and API ADAD composite (r = -0.25, p < 0.01, unadjusted for cortical SUVR_pons in florbetapir API ADAD cohort).

Conclusion: This PET study provides evidence of cerebellar Aβ plaque deposition in CU carriers starting about a decade before the clinical onset of ADAD. Additional studies are needed to clarify the impact of using a cerebellar versus pons reference region on the power to detect and track ADAD changes, even in preclinical stages of this disorder.
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http://dx.doi.org/10.1016/j.nicl.2021.102749DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8278433PMC
September 2021

Vascular Lesions, APOE ε4, and Tau Pathology in Alzheimer Disease.

J Neuropathol Exp Neurol 2021 Feb;80(3):240-246

Banner Sun Health Research Institute, Sun City, Arizona, USA.

We sought to determine the associations among cerebral amyloid angiopathy (CAA), white matter rarefaction (WMR), circle of Willis atherosclerosis (CWA), and total microinfarct number with Braak neurofibrillary stage in postmortem individuals with and without Alzheimer disease (AD). Data from 355 cases of autopsied individuals with Braak stage I-VI who had antemortem consensus diagnoses of cognitively unimpaired (n = 183), amnestic mild cognitive impairment (n = 31), and AD dementia (n = 141) were used. The association between Braak stage and vascular lesions were individually assessed using multivariable linear regression that adjusted for age at death, APOE ε4 carrier status, sex, education, and neuritic plaque density. CAA (p = 0.007) and WMR (p < 0.001) were associated with Braak stage, independent of amyloid load; microinfarct number and CWA showed no association. Analyses of the interactions between APOE ε4 carrier status and vascular lesions found that greater WMR and positive ε4 carrier status were associated with higher Braak stages. These results suggest that CAA and WMR are statistically linked to the severity of AD-related NFT pathology. The statistical link between WMR and NFT load may be strengthened by the presence of APOE ε4 carrier status. An additional finding was that Lewy body pathology was most prevalent in higher Braak stages.
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http://dx.doi.org/10.1093/jnen/nlaa160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7899190PMC
February 2021

BACE inhibition causes rapid, regional, and non-progressive volume reduction in Alzheimer's disease brain.

Brain 2020 12;143(12):3816-3826

Merck and Co., Inc., Kenilworth, NJ, USA.

In the phase 3 EPOCH trial (Clinicaltrials.gov; NCT01739348), treatment with the BACE inhibitor verubecestat failed to improve cognition in patients with mild-to-moderate Alzheimer's disease, but was associated with reduced hippocampal volume after 78 weeks as assessed by MRI. The aims of the present exploratory analyses were to: (i) characterize the effect of verubecestat on brain volume by evaluating the time course of volumetric MRI changes for a variety of brain regions; and (ii) understand the mechanism through which verubecestat might cause hippocampal (and other brain region) volume loss by assessing its relationship to measures of amyloid, neurodegeneration, and cognition. Participants were aged 55-85 years with probable Alzheimer's disease dementia and a Mini Mental State Examination score ≥15 and ≤26. MRIs were obtained at baseline and at Weeks 13, 26, 52 and 78 of treatment. MRIs were segmented using Freesurfer and analysed using a tensor-based morphometry method. PET amyloid data were obtained with 18F-flutemetamol (Vizamyl®) at baseline and Week 78. Standardized uptake value ratios were generated with subcortical white matter as a reference region. Neurofilament light chain in the CSF was assessed as a biomarker of neurodegeneration. Compared with placebo, verubecestat showed increased MRI brain volume loss at Week 13 with no evidence of additional loss through Week 78. The verubecestat-related volumetric MRI loss occurred predominantly in amyloid-rich brain regions. Correlations between amyloid burden at baseline and verubecestat-related volumetric MRI reductions were not significant (r = 0.05 to 0.26, P-values > 0.27). There were no significant differences between verubecestat and placebo in changes from baseline in CSF levels of neurofilament light chain at Week 78 (increases of 7.2 and 14.6 pg/ml for verubecestat versus 19.7 pg/ml for placebo, P-values ≥ 0.1). There was a moderate correlation between volumetric MRI changes and cognitive decline in all groups including placebo at Week 78 (e.g. r = -0.45 to -0.55, P < 0.001 for whole brain), but the correlations were smaller at Week 13 and significant only for the verubecestat groups (e.g. r = -0.15 and -0.11, P < 0.04 for whole brain). Our results suggest that the verubecestat-associated MRI brain volume loss is not due to generalized, progressive neurodegeneration, but may be mediated by specific effects on BACE-related amyloid processes.
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http://dx.doi.org/10.1093/brain/awaa332DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8453290PMC
December 2020

Cognitive outcomes in trials of two BACE inhibitors in Alzheimer's disease.

Alzheimers Dement 2020 11 13;16(11):1483-1492. Epub 2020 Oct 13.

Merck & Co., Inc., Kenilworth, New Jersey, USA.

Introduction: The APECS and AMARANTH trials showed that beta-secretase (BACE) inhibitors verubecestat and lanabecestat failed to slow cognitive and functional decline in individuals with prodromal or early Alzheimer's disease. Here, the performance on secondary and exploratory cognitive measures in both studies is reported.

Methods: APECS (verubecestat) and AMARANTH (lanabecestat) were randomized, double-blind, placebo-controlled, parallel-group, 104-week clinical trials conducted by different sponsors. Measures included the 3-Domain Composite Cognition Score (CCS-3D), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Letter/Category Fluency, and Digit Symbol Coding.

Results: Verubecestat showed worsening on the CCS-3D Total Score, Episodic Memory, and Attention/Processing Speed domains. Lanabecestat showed worsening on the RBANS Total Score, Immediate Memory, and Visuospatial/Constructional Indexes. Both BACE inhibitors showed worsening on Digit Symbol Coding and improvements on Letter/Category Fluency.

Discussion: In both studies, many measures showed treatment-associated cognitive worsening, whereas verbal fluency tasks showed improvement.
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http://dx.doi.org/10.1002/alz.12164DOI Listing
November 2020

Examining Sex Differences in Markers of Cognition and Neurodegeneration in Autosomal Dominant Alzheimer's Disease: Preliminary Findings from the Colombian Alzheimer's Prevention Initiative Biomarker Study.

J Alzheimers Dis 2020 ;77(4):1743-1753

Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.

Background: Growing evidence suggests that there may be a sex-specific biological risk for Alzheimer's disease (AD). Individuals with autosomal dominant AD due to a mutation (E280A) in Presenilin-1 (PSEN1) are genetically determined to develop early-onset dementia and thus, have few age-related risk factors for AD that are known to vary by sex (i.e., cardiovascular disease, menopause, life expectancy).

Objective: Investigate sex differences in markers of cognition and neurodegeneration in autosomal dominant AD.

Methods: We conducted a retrospective study in 19 cognitively-unimpaired PSEN1 mutation carriers (age range 20-44; 11 females), 11 symptomatic carriers (age range 42-56; 8 females), and 23 matched non-carriers family members (age range 20-50; 13 females). We examined hippocampal volume ratio, CERAD Total Score, and CERAD Word List (i.e., Learning, Delayed Recall, and Recognition). Mann-Whitney U tests, Spearman correlations and regression models were conducted.

Results: There were no differential associations between age, CERAD Total Score, CERAD Word List-Learning, Delayed Recall, Recognition, and hippocampal volume ratio in male and female carriers and non-carriers. Cognitively-unimpaired female carriers showed better CERAD Total scores and CERAD Word List-Learning than cognitively-unimpaired male carriers, despite having similar hippocampal volume ratios. The interaction of sex and hippocampal volume ratio did not predict cognitive performance across groups.

Conclusion: Our preliminary findings suggest that cognitively-unimpaired female carriers showed a verbal memory reserve, and as disease progresses, female carriers did not exhibit a cognitive susceptibility to AD-related neurodegeneration. Future studies with larger samples of autosomal dominant AD are warranted to further understand sex differences in AD-related clinical and pathological markers.
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http://dx.doi.org/10.3233/JAD-200723DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075106PMC
September 2021

Associative memory and in vivo brain pathology in asymptomatic presenilin-1 E280A carriers.

Neurology 2020 09 1;95(10):e1312-e1321. Epub 2020 Jul 1.

From the Departments of Psychiatry (E.G.V., J.M., C.V.-C., A.A., J.S., Y.T.Q.), Neurology (A.P.S., D.R., R.S., K.A.J., Y.T.Q.), and Radiology (K.A.J.), Massachusetts General Hospital, Harvard Medical School, Boston; Grupo de Neurociencias (A.B., Y.B., F.L., Y.T.Q.), Universidad de Antioquia, Medellín, Colombia; Center for Alzheimer Research and Treatment (K.P., D.R., R.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Boston, MA; and Banner Alzheimer's Institute (P.N.T., E.M.R.), Phoenix, AZ.

Objective: To determine whether performance on the Free and Cued Selective Reminding Test (FCSRT) is associated with PET in vivo markers of brain pathology and whether it can distinguish those who will develop dementia later in life due to autosomal-dominant Alzheimer disease (AD) from age-matched controls.

Methods: Twenty-four cognitively unimpaired Presenilin-1 E280A carriers (mean age 36 years) and 28 noncarriers (mean age 37 years) underwent Pittsburg compound B-PET (amyloid), flortaucipir-PET (tau), and cognitive testing, including the FCSRT (immediate and delayed free and cued recall scores). Linear regressions were used to examine the relationships among FCSRT scores, age, mean cortical amyloid, and regional tau burden.

Results: Free and total recall scores did not differ between cognitively unimpaired mutation carriers and noncarriers. Greater age predicted lower free recall and delayed free and total recall scores in carriers. In cognitively impaired carriers, delayed free recall predicted greater amyloid burden and entorhinal tau, while worse immediate free recall scores predicted greater tau in the inferior temporal and entorhinal cortices. In turn, in all carriers, lower free and total recall scores predicted greater amyloid and regional tau pathology.

Conclusions: FCSRT scores were associated with in vivo markers of AD-related pathology in cognitively unimpaired individuals genetically determined to develop dementia. Difficulties on free recall, particularly delayed recall, were evident earlier in the disease trajectory, while difficulties on cued recall were seen only as carriers neared the onset of dementia, consistent with the pathologic progression of the disease. Findings suggest that the FCSRT can be a useful measure to track disease progression in AD.
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http://dx.doi.org/10.1212/WNL.0000000000010177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7538214PMC
September 2020

Plasma neurofilament light chain in the presenilin 1 E280A autosomal dominant Alzheimer's disease kindred: a cross-sectional and longitudinal cohort study.

Lancet Neurol 2020 06 26;19(6):513-521. Epub 2020 May 26.

Grupo de Neurociencias de Antioquia of Universidad de Antioquia, Medellín, Colombia.

Background: Neurofilament light chain (NfL) is a promising biomarker of active axonal injury and neuronal degeneration. We aimed to characterise cross-sectional and longitudinal plasma NfL measurements and determine the age at which NfL concentrations begin to differentiate between carriers of the presenilin 1 (PSEN1) E280A (Glu280Ala) mutation and age-matched non-carriers from the Colombian autosomal dominant Alzheimer's disease kindred.

Methods: In this cross-sectional and longitudinal cohort study, members of the familial Alzheimer's disease Colombian kindred aged 8-75 years with no other neurological or health conditions were recruited from the Alzheimer's Prevention Initiative Registry at the University of Antioquia (Medellín, Colombia) between Aug 1, 1995, and Dec 15, 2018. We used a single molecule array immunoassay and log-transformed data to examine the relationship between plasma NfL concentrations and age, and establish the earliest age at which NfL concentrations begin to diverge between mutation carriers and non-carriers.

Findings: We enrolled a cohort of 1070 PSEN1 E280A mutation carriers and 1074 non-carriers with baseline assessments; of these participants, longitudinal measures (with a mean follow-up of 6 years) were available for 242 mutation carriers and 262 non-carriers. Plasma NfL measurements increased with age in both groups (p<0·0001), and began to differentiate carriers from non-carriers when aged 22 years (22 years before the estimated median age at mild cognitive impairment onset of 44 years), although the ability of plasma NfL to discriminate between carriers and non-carriers only reached high sensitivity close to the age of clinical onset.

Interpretation: Our findings further support the promise of plasma NfL as a biomarker of active neurodegeneration in the detection and tracking of Alzheimer's disease and the evaluation of disease-modifying therapies.

Funding: National Institute on Aging, National Institute of Neurological Disorders and Stroke, Banner Alzheimer's Foundation, COLCIENCIAS, the Torsten Söderberg Foundation, the Swedish Research Council, the Swedish Alzheimer Foundation, the Swedish Brain Foundation, and the Swedish state under the ALF-agreement.
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http://dx.doi.org/10.1016/S1474-4422(20)30137-XDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7417082PMC
June 2020

The Alzheimer's Prevention Initiative Composite Cognitive Test: a practical measure for tracking cognitive decline in preclinical Alzheimer's disease.

Alzheimers Res Ther 2020 05 27;12(1):66. Epub 2020 May 27.

Pentara Corporation, 2261 E. 3300 S. Suite 200, Salt Lake City, UT, USA.

Background: There is growing interest in identifying sensitive composite cognitive tests to serve as primary endpoints in preclinical Alzheimer's disease (AD) treatment trials. We reported previously a composite cognitive test score sensitive to tracking preclinical AD decline up to 5 years prior to clinical diagnosis. Here we expand upon and refine this work, empirically deriving a composite cognitive test score sensitive to tracking preclinical AD decline up to 11 years prior to diagnosis and suitable for use as a primary endpoint in a preclinical AD trial.

Methods: This study used a longitudinal approach to maximize sensitivity to tracking progressive cognitive decline in people who progressed to the clinical stages of AD (n = 868) compared to those who remained cognitively unimpaired during the same time period (n = 989), thereby correcting for normal aging and practice effects. Specifically, we developed the Alzheimer's Prevention Initiative Preclinical Composite Cognitive test (APCC) to measure very early longitudinal cognitive decline in older adults with preclinical AD. Data from three cohorts from Rush University were analyzed using a partial least squares (PLS) regression model to identify optimal composites within different time periods prior to diagnosis, up to 11 years prior to diagnosis. The mean-to-standard deviation ratio (MSDRs) is an indicator of sensitivity to change and was used to inform the final calculation of the composite score.

Results: The optimal composite, the APCC, is calculated: 0.26*Symbol Digit Modalities + 2.24*MMSE Orientation to Time + 2.14*MMSE Orientation to Place + 0.53*Logical Memory Delayed Recall + 1.36* Word List-Delayed Recall + 0.68*Judgment of Line Orientation + 1.39*Raven's Progressive Matrices Matrices (subset of 9 items from A and B). The MSDR of the APCC in a population of preclinical AD individuals who eventually progress to cognitive impairment, compared to those who remained cognitively unimpaired during the same time period, was - 1.10 over 1 year.

Conclusions: The APCC is an empirically derived composite cognitive test score with high face validity that is sensitive to preclinical AD decline up to 11 years prior to diagnosis of the clinical stages of AD. The components of the APCC are supported by theoretical understanding of cognitive decline that occurs during preclinical AD. The APCC was used as a primary outcome in the API Generation Program trials.
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http://dx.doi.org/10.1186/s13195-020-00633-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254761PMC
May 2020

Baseline demographic, clinical, and cognitive characteristics of the Alzheimer's Prevention Initiative (API) Autosomal-Dominant Alzheimer's Disease Colombia Trial.

Alzheimers Dement 2020 07 17;16(7):1023-1030. Epub 2020 May 17.

Banner Alzheimer's Institute, Phoenix, Arizona, USA.

Introduction: The API AutosomalDominant AD (ADAD) Colombia Trial is a placebo-controlled clinical trial of crenezumab in 252 cognitively unimpaired 30 to 60-year-old Presenilin 1 (PSEN1) E280A kindred members, including mutation carriers randomized to active treatment or placebo and non-carriers who receive placebo.

Methods: Of the 252 enrolled, we present data on a total of 242 mutation carriers and non-carriers matched by age range, excluding data on 10 participants to protect participant confidentiality, genetic status, and trial integrity.

Results: We summarize demographic, clinical, cognitive, and behavioral data from 167 mutation carriers and 75 non-carriers, 30 to 53 years of age. Carriers were significantly younger than non-carriers ((mean age ± SD) 37 ± 5 vs 42 ± 6), had significantly lower Mini Mental Status Exam (MMSE) scores (28.8 ± 1.4 vs 29.2 ± 1.0), and had consistently lower memory scores.

Discussion: Although PSEN1 E280A mutation carriers in the Trial are cognitively unimpaired, they have slightly lower MMSE and memory scores than non-carriers. Their demographic characteristics are representative of the local population.
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http://dx.doi.org/10.1002/alz.12109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7819133PMC
July 2020

Alzheimer's Prevention Initiative Generation Program: Development of an genetic counseling and disclosure process in the context of clinical trials.

Alzheimers Dement (N Y) 2019 6;5:705-716. Epub 2019 Nov 6.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Introduction: As the number of Alzheimer's disease (AD) prevention studies grows, many individuals will need to learn their genetic and/or biomarker risk for the disease to determine trial eligibility. An alternative to traditional models of genetic counseling and disclosure is needed to provide comprehensive standardized counseling and disclosure of apolipoprotein E () results efficiently, safely, and effectively in the context of AD prevention trials.

Methods: A multidisciplinary Genetic Testing, Counseling, and Disclosure Committee was established and charged with operationalizing the Alzheimer's Prevention Initiative (API) Genetic Counseling and Disclosure Process for use in the API Generation Program trials. The objective was to provide consistent information to research participants before and during the counseling and disclosure session using standardized educational and session materials.

Results: The Genetic Testing, Counseling, and Disclosure Committee created a process consisting of eight components: requirements of testing and reports, psychological readiness assessment, determination of AD risk estimates, guidance for identifying providers of disclosure, predisclosure education, counseling and disclosure session materials, counseling and disclosure session flow, and assessing disclosure impact.

Discussion: The API Genetic Counseling and Disclosure Process provides a framework for large-scale disclosure of genotype results to study participants and serves as a model for disclosure of biomarker results. The process provides education to participants about the meaning and implication(s) of their results while also incorporating a comprehensive assessment of disclosure impact. Data assessing participant safety and psychological well-being before and after disclosure are still being collected and will be presented in a future publication.
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http://dx.doi.org/10.1016/j.trci.2019.09.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6944715PMC
November 2019

Brain imaging measurements of fibrillar amyloid-β burden, paired helical filament tau burden, and atrophy in cognitively unimpaired persons with two, one, and no copies of the APOE ε4 allele.

Alzheimers Dement 2020 04 16;16(4):598-609. Epub 2020 Jan 16.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Introduction: We previously characterized associations between brain imaging measurements of amyloid-β (Aβ) plaque burden and apolipoprotein E (APOE) ε4 gene dose in a small number of cognitively unimpaired late-middle-aged APOE ε4 homozygotes (HMs), heterozygotes (HTs), and noncarriers (NCs). We now characterize cross-sectional Aβ plaque, tau tangle, and cortical atrophy (neurodegeneration) measurements, classifications, and associations with age in a larger number of unimpaired HMs, HTs, and NCs over a wider age range.

Methods: We analyzed C Pittsburgh compound B (Aβ) positron emission tomography (PET), flortaucipir (tau) PET, and volumetric magnetic resonance imaging data from 164 study participants of age 47-86 years, including 26 APOE ε4 HMs, 48 HTs, and 90 NCs matched for age and sex.

Results: Aβ PET measurements rose, plateaued at the respective ages of 68 and 76, and then declined with age in unimpaired HM and HT groups. Compared with NCs, these two groups began to have significantly higher Aβ PET measurements at ages 62 and 70, respectively, and no longer had significantly higher measurements by ages 71 and 78, respectively. They began to have significantly higher entorhinal cortex tau PET measurements at ages 66 and 70, respectively, and no longer had significantly higher measurements by ages 74 and 78, respectively. Brain atrophy measurements tended to decline slowly with age in all three genetic groups. Their elevated tau PET measurements were attributable to those with positive Aβ PET scans. 41.0%, 18.0%, and 5.0% of the 47- to 70-year-old HMs, HTs, and NCs and 25.0%, 79.0%, and 38.0% of the 71- to 86-year-old HMs, HTs, and NCs had positive Aβ PET scans, and the long-term recall memory scores are significantly higher in the older HMs than in HT and NC groups, suggesting resistance to Aβ deposition in those HMs who remained unimpaired at older ages.

Conclusions: This study provides information about Aβ plaque burden, tau tangle burden, and neurodegeneration in cognitively unimpaired persons at three levels of genetic risk for AD. Unimpaired APOE ε4 HMs can be studied before their 70s to evaluate the understanding of factors, processes, and interventions involved in the predisposition to and prevention of AD, and after their 70s, to discover factors, processes, and interventions involved in the resilience or resistance to and prevention of AD.
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http://dx.doi.org/10.1016/j.jalz.2019.08.195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7187298PMC
April 2020

Efficacy and Safety of Lanabecestat for Treatment of Early and Mild Alzheimer Disease: The AMARANTH and DAYBREAK-ALZ Randomized Clinical Trials.

JAMA Neurol 2020 02;77(2):199-209

Eli Lilly and Company, Indianapolis, Indiana.

Importance: Alzheimer disease (AD) is a neurodegenerative disorder characterized by cognitive deterioration and impaired activities of daily living. Current treatments provide only minor symptomatic improvements with limited benefit duration. Lanabecestat, a brain-permeable inhibitor of human beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1/β-secretase), was developed to modify the clinical course of AD by slowing disease progression.

Objective: To assess whether lanabecestat slows the progression of AD compared with placebo in patients with early AD (mild cognitive impairment) and mild AD dementia.

Design, Setting, And Participants: AMARANTH (first patient visit on September 30, 2014; last patient visit on October 4, 2018) and DAYBREAK-ALZ (first patient visit on July 1, 2016; last patient visit on September 28, 2018) were randomized, placebo-controlled, phase 2/3 and phase 3 clinical trials lasting 104 weeks and 78 weeks, respectively. AMARANTH and DAYBREAK-ALZ were multicenter, global, double-blind studies conducted at 257 and 251 centers, respectively, located in 15 and 18 countries or territories, respectively. A population-based sample of men and women aged 55 to 85 years who met National Institute on Aging-Alzheimer's Association criteria for early AD or mild AD dementia was screened using cognitive assessments, and the presence of amyloid was confirmed. Patients were excluded for unstable medical conditions or medication use, significant cerebrovascular pathologic findings, or a history of vitiligo and/or current evidence of postinflammatory hypopigmentation. AMARANTH screened 6871 patients; 2218 (32.3%) were randomized, and 539 patients completed the study. DAYBREAK-ALZ screened 5706 patients; 1722 (30.2%) were randomized, and 76 patients completed the study.

Interventions: Patients were randomized (1:1:1) to once-daily oral doses of lanabecestat (20 mg), lanabecestat (50 mg), or placebo.

Main Outcomes And Measures: The primary outcome measure was change from baseline on the 13-item Alzheimer Disease Assessment Scale-cognitive subscale. Secondary outcomes included Alzheimer's Disease Cooperative Study-Instrumental Activities of Daily Living Inventory, Clinical Dementia Rating, Functional Activities Questionnaire, Mini-Mental State Examination, and Neuropsychiatric Inventory. Efficacy analyses were conducted on the intent-to-treat population.

Results: Among 2218 AMARANTH patients, the mean (SD) age was 71.3 (7.1) years, and 1177 of 2218 (53.1%) were women. Among 1722 DAYBREAK-ALZ patients, the mean (SD) age was 72.3 (7.0) years, and 1023 of 1722 (59.4%) were women. Both studies were terminated early after futility analysis. There were no consistent, reproducible dose-related findings on primary or secondary efficacy measures. Psychiatric adverse events, weight loss, and hair color changes were reported in a higher percentage of patients receiving lanabecestat than placebo.

Conclusions And Relevance: Treatment with lanabecestat was well tolerated and did not slow cognitive or functional decline.

Trial Registration: ClinicalTrials.gov identifiers: NCT02245737 and NCT02783573.
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http://dx.doi.org/10.1001/jamaneurol.2019.3988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902191PMC
February 2020

Resistance to autosomal dominant Alzheimer's disease in an APOE3 Christchurch homozygote: a case report.

Nat Med 2019 11 4;25(11):1680-1683. Epub 2019 Nov 4.

The Banner Alzheimer's Institute, Phoenix, AZ, USA.

We identified a PSEN1 (presenilin 1) mutation carrier from the world's largest autosomal dominant Alzheimer's disease kindred, who did not develop mild cognitive impairment until her seventies, three decades after the expected age of clinical onset. The individual had two copies of the APOE3 Christchurch (R136S) mutation, unusually high brain amyloid levels and limited tau and neurodegenerative measurements. Our findings have implications for the role of APOE in the pathogenesis, treatment and prevention of Alzheimer's disease.
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http://dx.doi.org/10.1038/s41591-019-0611-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6898984PMC
November 2019

Impact of Zumba on Cognition and Quality of Life is Independent of APOE4 Carrier Status in Cognitively Unimpaired Older Women: A 6-Month Randomized Controlled Pilot Study.

Am J Alzheimers Dis Other Demen 2020 Jan-Dec;35:1533317519868370. Epub 2019 Aug 11.

Department of Neurology, Mayo Clinic, Scottsdale, AZ, USA.

Objective: To investigate the association of a 6-month Zumba intervention with cognition and quality of life among older cognitively unimpaired apolipoprotein ∊4 (APOE4) carrier and noncarrier women.

Methods: Fifty-three women were randomly assigned to either twice-weekly Zumba group classes or maintenance of habitual exercise (control group) for 6 months. At baseline, 3, and 6 months, all participants underwent neuropsychological, physical activity, and quality-of-life assessments.

Results: Overall, neuropsychological test scores and level of physical activity did not differ between intervention and control groups at any time. However, compared to the control group, quality of life was higher at 3 months, and visuospatial working memory and response inhibition improved more in the intervention group by 6 months. Apolipoprotein ∊4 status did not affect the results.

Discussion: Zumba may strengthen performance on visuospatial working memory among cognitively unimpaired older women but this needs to be tested in a larger clinical trial.
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http://dx.doi.org/10.1177/1533317519868370DOI Listing
December 2020

Further analyses of the safety of verubecestat in the phase 3 EPOCH trial of mild-to-moderate Alzheimer's disease.

Alzheimers Res Ther 2019 08 7;11(1):68. Epub 2019 Aug 7.

Merck & Co., Inc., Kenilworth, NJ, USA.

Background: Verubecestat, a BACE1 inhibitor that reduces Aβ levels in the cerebrospinal fluid of humans, was not effective in a phase 3 trial (EPOCH) of mild-to-moderate AD and was associated with adverse events. To assist in the development of BACE1 inhibitors, we report detailed safety findings from EPOCH.

Methods: EPOCH was a randomized, double-blind, placebo-controlled 78-week trial evaluating verubecestat 12 mg and 40 mg in participants with mild-to-moderate AD diagnosed clinically. The trial was terminated due to futility close to its scheduled completion. Of 1957 participants who were randomized and took treatment, 652 were assigned to verubecestat 12 mg, 652 to verubecestat 40 mg, and 653 to placebo. Adverse events and relevant laboratory, vital sign, and ECG findings were assessed.

Results: Verubecestat 12 mg and 40 mg were associated with an increase in the percentage of participants reporting adverse events versus placebo (89 and 92% vs. 82%), although relatively few participants discontinued treatment due to adverse events (8 and 9% vs. 6%). Adverse events that were increased versus placebo included falls and injuries, suicidal ideation, weight loss, sleep disturbance, rash, and hair color change. Most were mild to moderate in severity. Treatment differences in suicidal ideation emerged within the first 3 months but did not appear to increase after 6 months. In contrast, treatment differences in falls and injuries continued to increase over time.

Conclusions: Verubecestat was associated with increased risk for several types of adverse events. Falls and injuries were notable for progressive increases over time. While the mechanisms underlying the increased adverse events are unclear, they may be due to BACE inhibition and should be considered in future clinical development programs of BACE1 inhibitors.

Trial Registration: ClinicalTrials.gov NCT01739348 , registered on 29 November 2012.
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http://dx.doi.org/10.1186/s13195-019-0520-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6685277PMC
August 2019

Normative data stratified by age and education for a Spanish neuropsychological test battery: Results from the Colombian Alzheimer's prevention initiative registry.

Appl Neuropsychol Adult 2021 Mar-Apr;28(2):230-244. Epub 2019 Jun 23.

Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia.

Neuropsychologists continue to face challenges when assessing Spanish-speaking individuals due to limited availability of normative data. We developed comprehensive normative data stratified by age and education for a Spanish neuropsychological test battery used by the Grupo de Neurociencias de Antioquia (Colombia) and the Colombian Alzheimer's Prevention Initiative Registry, which have followed large families at risk for autosomal-dominant Alzheimer's disease (ADAD) since the 1990s. Approximately 75% of these individuals are cognitively-unimpaired and are not genetically predisposed to develop ADAD. We conducted a retrospective study on neuropsychological evaluations from 2,673 cognitively unimpaired individuals (56% female), with ages ranging from 18 to 86 years and education from 1 to 25 years. Neuropsychological measures included the Consortium to Establish a Registry for Alzheimer's Disease-Colombia, and other multidomain Spanish tests. We examined associations between age, education, and sex with cognitive performance. Norms stratified by age and education are presented. Cognitive performance showed small associations with age and education and was unrelated to sex. We provided population-based norms for Spanish tests targeting multiple cognitive domains using a large Colombian sample. These normative data may be helpful for the neuropsychological characterization of Spanish speakers from Latin America in clinical and research settings.
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http://dx.doi.org/10.1080/23279095.2019.1627357DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926163PMC
June 2019

The Alzheimer's Prevention Initiative Generation Program: Study design of two randomized controlled trials for individuals at risk for clinical onset of Alzheimer's disease.

Alzheimers Dement (N Y) 2019 12;5:216-227. Epub 2019 Jun 12.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Introduction: Alzheimer's disease (AD) pathology, including the accumulation of amyloid beta (Aβ) species and tau pathology, begins decades before the onset of cognitive impairment. This long preclinical period provides an opportunity for clinical trials designed to prevent or delay the onset of cognitive impairment due to AD. Under the umbrella of the Alzheimer's Prevention Initiative Generation Program, therapies targeting Aβ, including CNP520 (umibecestat), a β-site-amyloid precursor protein cleaving enzyme-1 (BACE-1) inhibitor, and CAD106, an active Aβ immunotherapy, are in clinical development in preclinical AD.

Methods: The Alzheimer's Prevention Initiative Generation Program comprises two pivotal (phase 2/3) studies that assess the efficacy and safety of umibecestat and CAD106 in cognitively unimpaired individuals with high risk for developing symptoms of AD based on their age (60-75 years), genotype, and, for heterozygotes ( ε2/ε4 or ε3/ε4), elevated brain amyloid. Approximately, 3500 individuals will be enrolled in either Generation Study 1 (randomized to cohort 1 [CAD106 injection or placebo, 5:3] or cohort 2 [oral umibecestat 50 mg or placebo, 3:2]) or Generation Study 2 (randomized to oral umibecestat 50 mg and 15 mg, or placebo [2:1:2]). Participants receive treatment for at least 60 months and up to a maximum of 96 months. Primary outcomes include time to event, with event defined as diagnosis of mild cognitive impairment due to AD and/or dementia due to AD, and the Alzheimer's Prevention Initiative preclinical composite cognitive test battery. Secondary endpoints include the Clinical Dementia Rating Sum of Boxes, Repeatable Battery for the Assessment of Neuropsychological Status total score, Everyday Cognition Scale, biomarkers, and brain imaging.

Discussion: The Generation Program is designed to assess the efficacy, safety, and biomarker effects of the two treatments in individuals at high risk for AD. It may also provide a plausible test of the amyloid hypothesis and further accelerate the evaluation of AD prevention therapies.
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http://dx.doi.org/10.1016/j.trci.2019.02.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6562315PMC
June 2019

Enrichment factors for clinical trials in mild-to-moderate Alzheimer's disease.

Alzheimers Dement (N Y) 2019 20;5:164-174. Epub 2019 May 20.

H. Lundbeck A/S, Valby, Denmark.

Introduction: Heterogeneity of outcomes in Alzheimer's disease (AD) clinical trials necessitates large sample sizes and contributes to study failures. This analysis determined whether mild-to-moderate AD populations could be enriched for cognitive decline based on apolipoprotein () ε4 genotype, family history of AD, and amyloid abnormalities.

Methods: Modeling estimated the number of randomized patients needed to detect a 2-point treatment difference on the AD Assessment Scale-Cognitive subscale using placebo data from three randomized, double-blind trials (ClinicalTrials.gov Identifiers: NCT01955161, NCT02006641, and NCT02006654).

Results: An 80% power to detect a 2-point treatment effect required the randomization of 148 amyloid-positive patients; 178 ε4 homozygous or amyloid-positive patients; and 231 ε4 homozygous, family history-positive, or amyloid-positive patients, compared with 1619 unenriched patients (per arm).

Discussion: Enrichment in mild-to-moderate AD clinical trials can be achieved using combinations of biomarkers/risk factors to increase the likelihood of observing potential treatment effects.
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http://dx.doi.org/10.1016/j.trci.2019.04.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6527908PMC
May 2019

Randomized Trial of Verubecestat for Prodromal Alzheimer's Disease.

N Engl J Med 2019 Apr;380(15):1408-1420

From Merck, Kenilworth, NJ (M.F.E., J.K., T.V., Y. Mukai, Y.Z., W.L., C.F., E.M., L.H.M., Y. Mo, C.S., D.M.); the University of Southern California, San Diego (P.S.A.); Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas (J.L.C.); Banner Alzheimer's Institute, Phoenix, AZ (P.N.T.); Gerontopole, INSERM Unité 1027, Alzheimer's Disease Research and Clinical Center, Toulouse University Hospital, Toulouse, France (B.V.); Yale University School of Medicine, New Haven, CT (C.H.D.); and the Research Center and Memory Clínic, Fundació Alzheimer Centre Educacional, Institut Català de Neurociènces Aplicades-Universitat Internacional de Catalunya, Barcelona, and the Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid - both in Spain (M.B.).

Background: Prodromal Alzheimer's disease offers an opportunity to test the effect of drugs that modify the deposition of amyloid in the brain before the onset of dementia. Verubecestat is an orally administered β-site amyloid precursor protein-cleaving enzyme 1 (BACE-1) inhibitor that blocks production of amyloid-beta (Aβ). The drug did not prevent clinical progression in a trial involving patients with mild-to-moderate dementia due to Alzheimer's disease.

Methods: We conducted a randomized, double-blind, placebo-controlled, 104-week trial to evaluate verubecestat at doses of 12 mg and 40 mg per day, as compared with placebo, in patients who had memory impairment and elevated brain amyloid levels but whose condition did not meet the case definition of dementia. The primary outcome was the change from baseline to week 104 in the score on the Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB; scores range from 0 to 18, with higher scores indicating worse cognition and daily function). Secondary outcomes included other assessments of cognition and daily function.

Results: The trial was terminated for futility after 1454 patients had been enrolled; 485 had been assigned to receive verubecestat at a dose of 12 mg per day (the 12-mg group), 484 to receive verubecestat at a dose of 40 mg per day (the 40-mg group), and 485 to receive placebo. A total of 234 patients, 231 patients, and 239 patients per group, respectively, completed 104 weeks of the trial regimen. The estimated mean change from baseline to week 104 in the CDR-SB score was 1.65 in the 12-mg group, 2.02 in the 40-mg group, and 1.58 in the placebo group (P = 0.67 for the comparison between the 12-mg group and the placebo group and P = 0.01 for the comparison between the 40-mg group and the placebo group), suggesting a worse outcome in the higher-dose group than in the placebo group. The estimated rate of progression to dementia due to Alzheimer's disease was 24.5, 25.5, and 19.3 events per 100 patient-years in the 12-mg group, the 40-mg group, and the placebo group, respectively (hazard ratio for 40 mg vs. placebo, 1.38; 97.51% confidence interval, 1.07 to 1.79, not adjusted for multiple comparisons), favoring placebo. Adverse events were more common in the verubecestat groups than in the placebo group.

Conclusions: Verubecestat did not improve clinical ratings of dementia among patients with prodromal Alzheimer's disease, and some measures suggested that cognition and daily function were worse among patients who received verubecestat than among those who received placebo. (Funded by Merck Sharp & Dohme; ClinicalTrials.gov number, NCT01953601.).
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http://dx.doi.org/10.1056/NEJMoa1812840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776078PMC
April 2019

GeneMatch: A novel recruitment registry using at-home APOE genotyping to enhance referrals to Alzheimer's prevention studies.

Alzheimers Dement 2019 04 13;15(4):515-524. Epub 2019 Feb 13.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Introduction: Recruitment for Alzheimer's disease (AD) prevention research studies is challenging because of lack of awareness among cognitively healthy adults coupled with the high screen fail rate due to participants not having a genetic risk factor or biomarker evidence of the disease. Participant recruitment registries offer one solution for efficiently and effectively identifying, characterizing, and connecting potential eligible volunteers to studies.

Methods: Individuals aged 55-75 years who live in the United States and self-report not having a diagnosis of cognitive impairment such as MCI or dementia are eligible to join GeneMatch. Participants enroll online and are provided a cheek swab kit for DNA extraction and apolipoprotein E (APOE) genotyping. Participants are not told their APOE results, although the results may be used in part to help match participants to AD prevention studies.

Results: As of August 2018, 75,351 participants had joined GeneMatch. Nearly 30% of participants have one APOE4 allele, and approximately 3% have two APOE4 alleles. The percentages of APOE4 heterozygotes and homozygotes are inversely associated with age (P < .001).

Discussion: GeneMatch, the first trial-independent research enrollment program designed to recruit and refer cognitively healthy adults to AD prevention studies based in part on APOE test results, provides a novel mechanism to accelerate prescreening and enrollment for AD prevention trials.
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http://dx.doi.org/10.1016/j.jalz.2018.12.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461487PMC
April 2019

Present Algorithms and Future Treatments for Alzheimer's Disease.

J Alzheimers Dis 2019 ;67(4):1157-1171

Banner Alzheimer's Institute, Phoenix, AZ, USA.

An estimated 47 million people live with Alzheimer's disease (AD) and other forms of dementia worldwide. Although no disease-modifying treatments are currently available for AD, earlier diagnosis and proper management of the disease could have considerable impact on patient and caregiver quality of life and functioning. Drugs currently approved for AD treat the cognitive, behavioral, and functional symptoms of the disease and consist of three cholinesterase inhibitors (ChEIs) and the N-methyl-D-aspartate receptor antagonist memantine. Treatment of patients with mild to moderate AD is generally initiated with a ChEI. Patients who show progression of symptoms while on ChEI monotherapy may be switched to another ChEI and/or memantine can be added to the treatment regimen. In recent years, putative disease-modifying therapies have emerged that aim to slow the progression of AD instead of only addressing its symptoms. However, many therapies have failed in clinical trials in patients with established AD, suggesting that, once developed, disease-modifying agents may need to be deployed earlier in the course of illness. The goal of this narrative literature review is to discuss present treatment algorithms and potential future therapies in AD.
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http://dx.doi.org/10.3233/JAD-180903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6484274PMC
May 2020

Open-Label, Multicenter, Phase III Extension Study of Idalopirdine as Adjunctive to Donepezil for the Treatment of Mild-Moderate Alzheimer's Disease.

J Alzheimers Dis 2019 ;67(1):303-313

Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA.

This open-label extension study evaluated the long-term safety and tolerability of idalopirdine 60 mg/day as adjunctive therapy in patients with mild-moderate Alzheimer's disease (AD). This extension study was a continuation of Studies 1 and 2 of the Phase III development program for idalopirdine and comprised a 28-week open-label treatment period ("OLEX") and a subsequent 24-week open-label treatment period with memantine ("MEMOLEX") in selected patients. The previous studies had shown no evidence of efficacy with idalopirdine as adjunctive treatment to donepezil but with good tolerability (of 1,791 patients randomized, 1,609 [90%] completed the double-blind studies). Of those, 1,463 patients (91%) entered the open-label extension study. During the 28-week OLEX period, the percentage of patients having treatment-emergent adverse events (TEAEs) ranged between 51% and 59% across the treatment groups originating from the lead-in studies. During the subsequent 24-week MEMOLEX period, 51% of the patients had TEAEs. Increases in liver enzymes (occurring in 1-3% of trial participants) were transient and no new safety signals were observed with longer term exposure. No consistent effects demonstrating benefits with idalopirdine were observed on efficacy parameters when patients transitioned to 60 mg in the extension study. Overall, idalopirdine was safe and well tolerated when added to donepezil, and when memantine was added to a prior combination of idalopirdine and donepezil. There were no new safety signals observed with up to 18 months of exposure at the described doses to idalopirdine.
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http://dx.doi.org/10.3233/JAD-180595DOI Listing
March 2020

Insights into globalization: comparison of patient characteristics and disease progression among geographic regions in a multinational Alzheimer's disease clinical program.

Alzheimers Res Ther 2018 11 24;10(1):116. Epub 2018 Nov 24.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Background: Globalization of clinical trials has important consequences for trial planning and interpretation. This study investigated heterogeneity in patient characteristics and outcomes among world regions in the global idalopirdine Phase 3 clinical program.

Methods: Data were pooled from three 24-week randomized controlled trials in patients aged ≥ 50 years with mild-to-moderate Alzheimer's disease (AD) (n = 2506). Patients received idalopirdine (10, 30, or 60 mg/day) or placebo, added to cholinesterase inhibitor treatment. Patients were categorized into the following regions: Eastern Europe/Turkey (n = 759), Western Europe/Israel (n = 709), USA/Canada (n = 444), South America/Mexico (n = 361), Asia (n = 134), and Australia/South Africa (n = 99). For each region, operational characteristics, baseline demographic and clinical characteristics, adverse events, and mean change from baseline to week 24 in clinical rating scale scores (placebo group only) were summarized using descriptive statistics.

Results: Completion rates were 0.86-0.90 in all regions. Heterogeneity among global regions was evident. Protocol deviations were twice as common in South America/Mexico as in USA/Canada (2.64 vs 1.35 per patient screened). Educational level ranged from 9.2 years in South America/Mexico to 13.4 years in USA/Canada. APOE ε4 carriage was 80.6% in Australia/South Africa, 63.1% in Western Europe/Israel, and < 60% in other regions. Screening Mini-Mental State Examination scores were higher in Eastern Europe/Turkey (18.0) and USA/Canada (17.5) than in other regions (16.9-17.1). Baseline AD Assessment Scale-Cognitive subscale (ADAS-Cog) scores ranged from 24.3 in USA/Canada to 27.2 in South America/Mexico. Baseline AD Cooperative Study-Activities of Daily Living, 23-item version (ADCS-ADL) scores ranged from 58.5 in USA/Canada to 53.5 in Eastern Europe/Turkey. In the placebo group, adverse events were 1.6-1.7 times more common in Western Europe/Israel, USA/Canada, and Australia/South Africa than in Eastern Europe/Turkey. On the ADAS-Cog, Australia/South Africa and Western Europe/Israel showed the most worsening among patients receiving placebo (1.56 and 1.40 points, respectively), whereas South America/Mexico showed an improvement (-0.71 points). All regions worsened on the ADCS-ADL, from -3.21 points in Western Europe/Israel to -0.59 points in Eastern Europe/Turkey.

Conclusions: Regional heterogeneity-in terms of study conduct, patient characteristics, and outcomes-exists, and should be accounted for, when planning and conducting multinational AD clinical trials.

Trial Registration: ClinicalTrials.gov, NCT01955161 . Registered on 27 September 2013. ClinicalTrials.gov, NCT02006641 . Registered on 5 December 2013. ClinicalTrials.gov, NCT02006654 . Registered on 5 December 2013.
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http://dx.doi.org/10.1186/s13195-018-0443-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6260857PMC
November 2018

Adherence/Retention Alzheimer's Prevention Initiative Colombia Plan.

Alzheimers Dement (N Y) 2018 14;4:283-287. Epub 2018 Jul 14.

Grupo de Neurociencias, Universidad de Antioquia, SIU, Medellín, Colombia.

Introduction: The Alzheimer's Prevention Initiative Colombia Trial is a collaborative project involving the Neurosciences Group of Antioquia, Genentech/Roche, and the Banner Alzheimer's Institute, studying whether crenezumab can delay or prevent the clinical onset of Alzheimer's disease in cognitively unimpaired individuals who carry the mutation. In an effort to optimize participant compliance and adherence and maintain interest in the trial for its duration, the Neurosciences Group of Antioquia developed an "Adherence/Retention Plan." This plan identifies potential barriers to trial adherence related to characteristics of the participants and study partners, protocol design, sponsors, investigators, environmental factors, and characteristics of this population in general and identifies potential solutions to these barriers.

Methods: Neurosciences Group of Antioquia designed and implemented a number of strategies including a) a prescreening process that emphasized detailed and staged informed consent involving the participant and family and/or friends, b) a schedule of visits and assessments designed to minimize burden while achieving the trial's aims, c) appointment reminders, d) reimbursement for transportation and missed work, e) meals during study visits, f) birthday cards, g) quarterly newsletters, h) annual in-person feedback meetings, i) a supplemental health plan to participants, and j) a social plan to support family members. All the methods used in this plan were approved by local ethics committees.

Results: By the end of the fourth year of the trial, participant retention was 94.0%, with most participants reporting that they felt "very satisfied" with their participation in the trial.

Discussion: The Adherence/Retention Plan plays a crucial role in maintaining adherence and compliance needed to achieve the ambitious goals of the Alzheimer's Prevention Initiative-Colombia Autosomal Dominant Alzheimer's Disease Trial and may offer guideposts for other prevention trials.
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http://dx.doi.org/10.1016/j.trci.2018.06.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6077834PMC
July 2018

The Alzheimer's Prevention Initiative Autosomal-Dominant Alzheimer's Disease Trial: A study of crenezumab versus placebo in preclinical E280A mutation carriers to evaluate efficacy and safety in the treatment of autosomal-dominant Alzheimer's disease, including a placebo-treated noncarrier cohort.

Alzheimers Dement (N Y) 2018 8;4:150-160. Epub 2018 Mar 8.

Banner Alzheimer's Institute, Phoenix, AZ, USA.

Introduction: Autosomal-dominant Alzheimer's disease (ADAD) represents a crucial population for identifying prevention strategies that might modify disease course for cognitively unimpaired individuals at high imminent risk for developing symptoms due to Alzheimer's disease (AD), that is, who have "preclinical" AD. Crenezumab is an antiamyloid monoclonal antibody that binds monomeric and aggregated forms of amyloid β, with highest affinity for oligomers; it is in development for early stages of sporadic AD and for ADAD.

Methods: This is a prospective, randomized, double-blind, placebo-controlled phase 2 study of the efficacy of crenezumab versus placebo in asymptomatic E280A mutation carriers from family kindreds with ADAD in Colombia. Participants were randomized to receive either crenezumab or placebo for 260 weeks. The study was designed to enroll a planned total of 300 participants, including 200 preclinical mutation carriers (approximately 100 treatment, 100 placebo) and an additional control group of mutation noncarriers from the same family kindreds included to mask mutation carrier status (100 placebo only). The primary outcome is change in the Alzheimer's Prevention Initiative ADAD Composite Cognitive Test Score from baseline to week 260. Secondary outcomes include time to progression to mild cognitive impairment due to AD or dementia due to AD; changes in dementia severity, memory, and overall neurocognitive functioning; and changes in amyloid-positron emission tomography, fluorodeoxyglucose-positron emission tomography, magnetic resonance imaging volumes, and cerebrospinal fluid levels of β amyloid, tau, and p-tau. Safety and tolerability are assessed.

Results: Two hundred fifty-two participants were enrolled between December 2013 and February 2017.

Discussion: We describe the first large-scale, potentially label-enabling clinical trial of a preclinical treatment for ADAD. Results from this trial will inform on the efficacy of crenezumab for delaying onset of, slowing decline in, or preventing cognitive impairment in individuals with preclinical ADAD and will foster an improved understanding of AD biomarkers and their relationship to clinical outcomes.
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http://dx.doi.org/10.1016/j.trci.2018.02.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6021543PMC
March 2018

Randomized Trial of Verubecestat for Mild-to-Moderate Alzheimer's Disease.

N Engl J Med 2018 05;378(18):1691-1703

From Merck Research Laboratories, Merck, Kenilworth, NJ (M.F.E., J.K., C.S., Y. Mukai, T.V., C.F., E.M., L.H.M., Y. Mo, D.M.); Banner Alzheimer's Institute, Phoenix, AZ (P.N.T.); University of Southern California, San Diego (P.S.A.); Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas (J.L.C.); Gerontopole, INSERM Unité 1027, Alzheimer's Disease Research and Clinical Center, Toulouse University Hospital, Toulouse, France (B.V.); and Leuven Institute of Neuroscience and Disease, Alzheimer Research Center, and the Laboratory for Cognitive Neurology, Department of Neurosciences, Katholieke Universiteit Leuven, and Neurology, University Hospitals - both in Leuven, Belgium (R.V.).

Background: Alzheimer's disease is characterized by the deposition of amyloid-beta (Aβ) plaques in the brain. Aβ is produced from the sequential cleavage of amyloid precursor protein by β-site amyloid precursor protein-cleaving enzyme 1 (BACE-1) followed by γ-secretase. Verubecestat is an oral BACE-1 inhibitor that reduces the Aβ level in the cerebrospinal fluid of patients with Alzheimer's disease.

Methods: We conducted a randomized, double-blind, placebo-controlled, 78-week trial to evaluate verubecestat at doses of 12 mg and 40 mg per day, as compared with placebo, in patients who had a clinical diagnosis of mild-to-moderate Alzheimer's disease. The coprimary outcomes were the change from baseline to week 78 in the score on the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog; scores range from 0 to 70, with higher scores indicating worse dementia) and in the score on the Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory scale (ADCS-ADL; scores range from 0 to 78, with lower scores indicating worse function).

Results: A total of 1958 patients underwent randomization; 653 were randomly assigned to receive verubecestat at a dose of 12 mg per day (the 12-mg group), 652 to receive verubecestat at a dose of 40 mg per day (the 40-mg group), and 653 to receive matching placebo. The trial was terminated early for futility 50 months after onset, which was within 5 months before its scheduled completion, and after enrollment of the planned 1958 patients was complete. The estimated mean change from baseline to week 78 in the ADAS-cog score was 7.9 in the 12-mg group, 8.0 in the 40-mg group, and 7.7 in the placebo group (P=0.63 for the comparison between the 12-mg group and the placebo group and P=0.46 for the comparison between the 40-mg group and the placebo group). The estimated mean change from baseline to week 78 in the ADCS-ADL score was -8.4 in the 12-mg group, -8.2 in the 40-mg group, and -8.9 in the placebo group (P=0.49 for the comparison between the 12-mg group and the placebo group and P=0.32 for the comparison between the 40-mg group and the placebo group). Adverse events, including rash, falls and injuries, sleep disturbance, suicidal ideation, weight loss, and hair-color change, were more common in the verubecestat groups than in the placebo group.

Conclusions: Verubecestat did not reduce cognitive or functional decline in patients with mild-to-moderate Alzheimer's disease and was associated with treatment-related adverse events. (Funded by Merck; ClinicalTrials.gov number, NCT01739348 .).
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http://dx.doi.org/10.1056/NEJMoa1706441DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776074PMC
May 2018
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