Enrichment factors for clinical trials in mild-to-moderate Alzheimer's disease.
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ABSTRACT:
SUBMITTER: Ballard C
PROVIDER: S-EPMC6527908 | biostudies-literature | 2019
REPOSITORIES: biostudies-literature
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Enrichment factors for clinical trials in mild-to-moderate Alzheimer's disease.
Ballard Clive C Atri Alireza A Boneva Neli N Cummings Jeffrey L JL Frölich Lutz L Molinuevo José Luis JL Tariot Pierre N PN Raket Lars Lau LL
Alzheimer's & dementia (New York, N. Y.) 20190520
<h4>Introduction</h4>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 (<i>APOE</i>) ε4 genotype, family history of AD, and amyloid abnormalities.<h4>Methods</h4>Modeling estimated the number of randomized patients needed to detect a 2-point treatment difference on the AD Assessment ...[more]
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Project description:BackgroundIn randomized clinical trials (RCTs), monitoring adverse events (AEs) and serious AEs (SAEs) is critical. All Alzheimer's disease (AD) RCTs require participants to enroll with a study partner.ObjectiveWe examined AE reporting rates in mild-to-moderate AD trials and their associations with study partner type.MethodsWe estimated AE reporting rates using placebo data from seven independent RCTs conducted by the Alzheimer's Disease Cooperative Study. We assessed the heterogeneity of reporting rates as a function of visits using generalized estimating equations. In the primary analysis, we tested the hypotheses that the rates of reporting differed by study partner type and time they spent with the participant weekly using Poisson regression with robust variance estimation. In all regression models, log-transformed total patient years was included.ResultsThe estimated reporting rates were 2.83 (95% CI: 2.66, 3.02), 1.18 (95% CI: 1.09, 1.28), 0.23 (95% CI: 0.19, 0.27), and 0.28 (95% CI: 0.24, 0.33) events per participant year for grade 1-3 AEs and SAEs, respectively. We estimated that greater number of visits per year was associated with increased reporting for grade 1-2 AEs and SAEs. We did not find evidence to suggest that AE reporting differed by study partner type or by time the study partner spent with the participant.ConclusionsStudy partner type and time the study partner spent with the participant did not appear to impact AE reporting. Estimated reporting rates may be useful to evaluate safety in future studies, particularly those with no control arm and similar visit frequencies.
| S-EPMC10977362 | biostudies-literature
Project description:Background:Two previous studies of SB742457, a 5-hydroxytryptamine (5-HT6) receptor antagonist, suggested the efficacy of improvements in cognition and global outcome in Alzheimer's disease (AD). Methods:Two randomized, placebo-controlled trials investigated SB742457 15 and 35 mg daily in subjects with mild-to-moderate AD (Mini-Mental Health State Examination [MMSE] 10-26). Study 1 (n = 576) investigated SB742457 and donepezil (5-10 mg daily) as monotherapy for 6 months. Study 2 (n = 684) investigated SB742457 in subjects who were maintained on donepezil. Coprimary endpoints at 24 weeks assessed cognition (AD Assessment Scale-Cognitive Subscale [ADAS-Cog]) and global outcome (Study 1: Clinician Interview-Based Impression of Change Plus Caregiver Input [CIBIC+]; Study 2: Clinical Dementia Rating-Sum of Boxes [CDR-SB]). Safety was assessed throughout. Results:Both studies failed to achieve formal statistical significance for their primary objectives. Study 1: SB742457 monotherapy was not statistically significantly different from placebo on any endpoint. Donepezil improved CIBIC+ but not ADAS-Cog. Study 2: SB742457 35 mg showed statistically significant differences relative to placebo for ADAS-cog (weeks 12, 24, and 48, but not week 36), ADCS-ADL (weeks 12-36, but not week 48), and CDR-SB (week 12 only). Conclusion:Neither study met the overall criteria for success, but as an adjunct to donepezil, SB742457 was associated with sustained improvements for up to 48 weeks in cognition and ADL, compared with donepezil alone.Clinical Trial Registration: Clinicaltrials.gov: Study 1 NCT00708552; Study 2 NCT00710684.
| S-EPMC5974972 | biostudies-literature
Project description:BACKGROUND:Bapineuzumab, a humanized anti-amyloid-beta monoclonal antibody, is in clinical development for the treatment of Alzheimer's disease. METHODS:We conducted two double-blind, randomized, placebo-controlled, phase 3 trials involving patients with mild-to-moderate Alzheimer's disease--one involving 1121 carriers of the apolipoprotein E (APOE) ?4 allele and the other involving 1331 noncarriers. Bapineuzumab or placebo, with doses varying by study, was administered by intravenous infusion every 13 weeks for 78 weeks. The primary outcome measures were scores on the 11-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog11, with scores ranging from 0 to 70 and higher scores indicating greater impairment) and the Disability Assessment for Dementia (DAD, with scores ranging from 0 to 100 and higher scores indicating less impairment). A total of 1090 carriers and 1114 noncarriers were included in the efficacy analysis. Secondary outcome measures included findings on positron-emission tomographic amyloid imaging with the use of Pittsburgh compound B (PIB-PET) and cerebrospinal fluid phosphorylated tau (phospho-tau) concentrations. RESULTS:There were no significant between-group differences in the primary outcomes. At week 78, the between-group differences in the change from baseline in the ADAS-cog11 and DAD scores (bapineuzumab group minus placebo group) were -0.2 (P=0.80) and -1.2 (P=0.34), respectively, in the carrier study; the corresponding differences in the noncarrier study were -0.3 (P=0.64) and 2.8 (P=0.07) with the 0.5-mg-per-kilogram dose of bapineuzumab and 0.4 (P=0.62) and 0.9 (P=0.55) with the 1.0-mg-per-kilogram dose. The major safety finding was amyloid-related imaging abnormalities with edema among patients receiving bapineuzumab, which increased with bapineuzumab dose and APOE ?4 allele number and which led to discontinuation of the 2.0-mg-per-kilogram dose. Between-group differences were observed with respect to PIB-PET and cerebrospinal fluid phospho-tau concentrations in APOE ?4 allele carriers but not in noncarriers. CONCLUSIONS:Bapineuzumab did not improve clinical outcomes in patients with Alzheimer's disease, despite treatment differences in biomarkers observed in APOE ?4 carriers. (Funded by Janssen Alzheimer Immunotherapy and Pfizer; Bapineuzumab 301 and 302 ClinicalTrials.gov numbers, NCT00575055 and NCT00574132, and EudraCT number, 2009-012748-17.).
| S-EPMC4159618 | biostudies-literature
Project description:Introduction:The objective of this study was to estimate longitudinal changes in disease progression (measured by Alzheimer's disease assessment scale-cognitive 11-item [ADAS-cog/11] scale) after bapineuzumab treatment and to identify covariates (demographics or baseline characteristics) contributing to the variability in disease progression rate and baseline disease status. Methods:A population-based disease progression model was developed using pooled placebo and bapineuzumab data from two phase-3 studies in APOE ?4 noncarrier and carrier Alzheimer's disease (AD) patients. Results:A beta regression model with the Richard's function as the structural component best described ADAS-cog/11 disease progression for mild-to-moderate AD population. This analysis confirmed no effect of bapineuzumab exposure on ADAS-cog/11 progression rate, consistent with the lack of clinical efficacy observed in the statistical analysis of ADAS-cog/11 data in both studies. Assessment of covariates affecting baseline severity revealed that men had a 6% lower baseline ADAS-cog/11 score than women; patients who took two AD concomitant medications had a 19% higher (worse) baseline score; APOE ?4 noncarriers had a 5% lower baseline score; and patients who had AD for a longer duration had a higher baseline score. Furthermore, shorter AD duration, younger age, APOE ?4 carrier status, and use of two AD concomitant medications were associated with faster disease progression rates. Patients who had an ADAS-cog/11 score progression rate that was not statistically significantly different from 0 typically took no AD concomitant medications. Discussion:The beta regression model is a sensible modeling approach to characterize cognitive decline in AD patients. The influence of bapineuzumab exposure on disease progression measured by ADAS-cog/11 was not significant. Trial Registration:ClinicalTrials.gov identifier: NCT00575055 and NCT00574132.
| S-EPMC5975060 | biostudies-literature
Project description:Our objective was to evaluate the efficacy (clinical and biomarker) and safety of intravenous bapineuzumab in patients with mild to moderate Alzheimer's disease (AD).Two of four phase 3, multicenter, randomized, double-blind, placebo-controlled, 18-month trials were conducted globally: one in apolipoprotein E ?4 carriers and another in noncarriers. Patients received bapineuzumab 0.5 mg/kg (both trials) or 1.0 mg/kg (noncarrier trial) or placebo every 13 weeks. Coprimary endpoints were change from baseline to week 78 on the 11-item Alzheimer's Disease Assessment Scale-Cognitive subscale and the Disability Assessment for Dementia.A total of 683 and 329 patients completed the current carrier and noncarrier trials, respectively, which were terminated prematurely owing to lack of efficacy in the two other phase 3 trials of bapineuzumab in AD. The current trials showed no significant difference between bapineuzumab and placebo for the coprimary endpoints and no effect of bapineuzumab on amyloid load or cerebrospinal fluid phosphorylated tau. (Both measures were stable over time in the placebo group.) Amyloid-related imaging abnormalities with edema or effusion were confirmed as the most notable adverse event.These phase 3 global trials confirmed lack of efficacy of bapineuzumab at tested doses on clinical endpoints in patients with mild to moderate AD. Some differences in the biomarker results were seen compared with the other phase 3 bapineuzumab trials. No unexpected adverse events were observed.Noncarriers (3000) ClinicalTrials.gov identifier NCT00667810 ; registered 24 Apr 2008. Carriers (3001) ClinicalTrials.gov identifier NCT00676143 ; registered 2 May 2008.
| S-EPMC4866415 | biostudies-literature
Project description:BackgroundAlzheimer's disease (AD) is a globally prevalent neurodegenerative condition, clinically characterized by progressive memory loss and gradual impairment of cognitive functions. Bapineuzumab is a fully humanized monoclonal antibody that binds to neurotoxic amyloid proteins in the brain, enhancing their clearance. We performed this systematic review and meta-analysis to evaluate the safety and efficacy of bapineuzumab in patients with mild to moderate Alzheimer's disease.MethodsWe performed a web-based literature search of PubMed, Ovid, EBSCO, Scopus, Embase, Cochrane CENTRAL, and web of science using the relevant keywords. Data were extracted from eligible records and pooled as mean difference (MD) or risk ratio (RR) values with their 95% confidence interval (CI), using Review Manager software (version 5.3 for windows). Heterogeneity was measured by Chi-square and I-square tests.ResultThe pooled effect estimate from six randomized clinical trials (n = 2380) showed that bapineuzumab significantly reduced the cerebrospinal fluid concentration of phosphorylated tau proteins (Standardized MD = -5.53, 95% CI [-8.29, -2.76]). However, the bapineuzumab group was not superior to the placebo group in terms of change from baseline in Alzheimer's disease assessment scale (ADAS)-Cog11 (MD = 0.14, 95% CI [-0.72, 0.99]), disability assessment for dementia (DAD) scale (MD = 1.35, 95% CI [-1.74, 4.43]), and mini-mental state examination (MMSE) scores (MD = 0.08, 95% CI [-0.31, 0.47]). Regarding safety, bapineuzumab increased the risk of serious treatment-emergent adverse events (RR = 1.18, 95% CI [1.02, 1.37]) and cerebral vasogenic edema (RR = 40.88, 95% CI [11.94, 135.95]). All bapineuzumab doses (0.15, 0.5, 1, and 2 mg/kg) were similar to placebo in terms of change from baseline in ADAS-cog11, DAD, and MMSE scores, except for the 0.15 mg/kg dose, which caused a significant worsening on the ADAS-cog11 scale (MD = 5.6, 95% CI [0.22, 10.98]).ConclusionsConsidering the lack of clinical efficacy, combined with the significant association with serious adverse events, bapineuzumab should not be used to treat patients with mild to moderate AD. Future studies should investigate the effect of combining bapineuzumab with other therapeutic strategies and reevaluate the efficacy of targeting amyloid β proteins in AD therapy.
| S-EPMC5381133 | biostudies-literature
Project description:Recent clinical trials in mild Alzheimer disease (AD) have enriched for amyloid-specific positron emission tomography (PET) imaging and used extended versions of the AD Assessment Scale-Cognitive Subscale (ADAS-Cog) in an effort to increase the sensitivity to detect treatment effects. We used data from mild AD participants in the AD Neuroimaging Initiative to model trial effect sizes for 12- and 24-month trials using 3 versions of the ADAS-Cog and increased standardized uptake value ratio (SUVR) cutoffs for amyloid imaging inclusion criteria. For 12-month trials, extended ADAS-Cog versions improved effect sizes. The ADAS-Cog11 elicited larger effect sizes when enriching for SUVR 1.1 only, whereas the ADAS-Cog12 and ADAS-Cog13 were associated with larger effect sizes with higher SUVR thresholds. For 24-month trials, extended ADAS-Cog versions increased effect sizes for trials not enriched for amyloid and trials enriched for SUVR 1.1. Only enriching for higher SUVR thresholds (1.3 and 1.4, not 1.1) increased trial power. We conclude that extended versions of the ADAS-Cog improve mild AD trial effect sizes for both 12- and 24-month long studies, whereas amyloid imaging criteria may be most valuable for 12-month trials.
| S-EPMC5116001 | biostudies-literature
Project description:Alzheimer's disease (AD) is characterized by progressive declines in cognitive function and ability to carry out activities of daily living; and the emergence and worsening of behavioral/neuropsychiatric symptoms. While there is no cure for AD, non-pharmacologic interventions and medications that modulate neurotransmission can slow symptomatic progression. Medical foods may also be useful as adjuncts to pharmacologic agents in AD. Medium chain triglycerides aimed at improving cerebral metabolism significantly improve Alzheimer's Disease Assessment Scale-Cognitive scores when added to ongoing pharmacotherapy in patients with mild-to-moderate AD. Combination of interventions, such as non-pharmacologic treatments, pharmacotherapy, and medical foods, with complementary mechanisms of action may provide a rational approach that may result in maximum preservation of cognitive function in patients with AD.
| S-EPMC3437664 | biostudies-literature
Project description: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 .).
| S-EPMC6776074 | biostudies-literature
Project description:IntroductionThis study aims to evaluate the conceptual relevance of four measures of disease activity in patients with mild/mild-moderate Alzheimer's disease (AD): (1) the Alzheimer's Disease Assessment Scale-Cognitive Subscale; (2) the Alzheimer's Disease Cooperative Study-Activities of Daily Living Inventory; (3) the Neuropsychiatry Inventory; and (4) the Dependence Scale.MethodsA conceptual model depicting patient experience of mild AD was developed via literature review; concepts were compared with the items of the four measures. Relevance of the concepts included in the four measures was evaluated by patients with mild AD in a survey and follow-up interviews.ResultsThe four measures assessed few of the symptoms/impacts of mild AD identified within the literature. Measured items addressing emotional impacts were deemed most relevant by participants but were included in the measures only superficially.DiscussionThe four assessment measures do not appear to capture the concepts most relevant to/important to patients with mild/mild-moderate AD.
| S-EPMC6180432 | biostudies-literature