scholarly journals Diversity in Alzheimer's disease drug trials: The importance of eligibility criteria

2021 ◽  
Author(s):  
Sanne Franzen ◽  
Jade Emily Smith ◽  
Esther den Berg ◽  
Monica Rivera Mindt ◽  
Rozemarijn L. Bruchem‐Visser ◽  
...  
2021 ◽  
pp. 174077452110344
Author(s):  
Michelle M Nuño ◽  
Joshua D Grill ◽  
Daniel L Gillen ◽  

Background/Aims: The focus of Alzheimer’s disease studies has shifted to earlier disease stages, including mild cognitive impairment. Biomarker inclusion criteria are often incorporated into mild cognitive impairment clinical trials to identify individuals with “prodromal Alzheimer’s disease” to ensure appropriate drug targets and enrich for participants likely to develop Alzheimer’s disease dementia. The use of these eligibility criteria may affect study power. Methods: We investigated outcome variability and study power in the setting of proof-of-concept prodromal Alzheimer’s disease trials that incorporate cerebrospinal fluid levels of total tau (t-tau) and phosphorylated (p-tau) as primary outcomes and how differing biomarker inclusion criteria affect power. We used data from the Alzheimer’s Disease Neuroimaging Initiative to model trial scenarios and to estimate the variance and within-subject correlation of total and phosphorylated tau. These estimates were then used to investigate the differences in study power for trials considering these two surrogate outcomes. Results: Patient characteristics were similar for all eligibility criteria. The lowest outcome variance and highest within-subject correlation were obtained when phosphorylated tau was used as an eligibility criterion, compared to amyloid beta or total tau, regardless of whether total tau or phosphorylated tau were used as primary outcomes. Power increased when eligibility criteria were broadened to allow for enrollment of subjects with either low amyloid beta or high phosphorylated tau. Conclusion: Specific biomarker inclusion criteria may impact statistical power in trials using total tau or phosphorylated tau as the primary outcome. In concert with other important considerations such as treatment target and population of clinical interest, these results may have implications to the integrity and efficiency of prodromal Alzheimer’s disease trial designs.


Author(s):  
B. Vellas ◽  
P. Aisen ◽  
M. Weiner ◽  
J. Touchon

We are happy to publish the CTAD 2018 abstracts in the present JPAD issue. As you can see many new interesting studies are presented in this issue of the journal: from new drug trials to biomarkers, imaging studies, as well as new clinical outcomes. More specifically, we will have several hot topics presentation on: 1. Major drug trials using bace inhibitors (verubecestat, lanabecestat, atabecestat, elenbecestat…) in the early phase of the disease (APECS early trials…). Both clinical, biomarkers (MRI, CSF, PET) and safety data will be presented. 2. New data on blood biomarkers including a keynote from R. Bateman, and presentations from Araclon and Roche biomarkers. 3. Results from phase III and IIB trials including a novel and multi-targeted oligosaccharide in patients with mild-moderate AD in China; the AMBAR (Alzheimer’s Management By Albumin Replacement) study, the TOMMORROW trial: a trial to delay the onset of MCI due to AD and qualify a genetic biomarker algorithm, the 18-month STEADFAST trial of azeliragon in participants with mild Alzheimer’s Disease; a longitudinal 148-week extension 4. Results 18 from F-AV-1451-A16: a clinicopathological study of the correspondence between flortaucipir PET imaging and post-mortem assessment of tau pathology. 5. Latest developments in anti-amyloid monoclonal antibodies including aducanumab nonnegligible, and new results and data analyses of the BAN2401 study 201 in early AD. 6. New developments with safety and efficacy of lemborexant for sleep-wake regulation in patients with irregular sleep-wake rhythm disorders and Alzheimer’s Disease dementia. 7. Advances with the ABBV-8E12, a humanized anti-tau monoclonal antibody, for the treatment of early Alzheimer’s Disease. 8. Endpoints for early Alzheimer’s Disease clinical trials: interpretation and application of the draft FDA guidance. And many others… It is important to underline that a not negligible number of abstracts concern non amyloid targets (eg: Tau-related targets but also targets outside the classical AD cascade).


2020 ◽  
Vol 78 (4) ◽  
pp. 1547-1574
Author(s):  
Sofia de la Fuente Garcia ◽  
Craig W. Ritchie ◽  
Saturnino Luz

Background: Language is a valuable source of clinical information in Alzheimer’s disease, as it declines concurrently with neurodegeneration. Consequently, speech and language data have been extensively studied in connection with its diagnosis. Objective: Firstly, to summarize the existing findings on the use of artificial intelligence, speech, and language processing to predict cognitive decline in the context of Alzheimer’s disease. Secondly, to detail current research procedures, highlight their limitations, and suggest strategies to address them. Methods: Systematic review of original research between 2000 and 2019, registered in PROSPERO (reference CRD42018116606). An interdisciplinary search covered six databases on engineering (ACM and IEEE), psychology (PsycINFO), medicine (PubMed and Embase), and Web of Science. Bibliographies of relevant papers were screened until December 2019. Results: From 3,654 search results, 51 articles were selected against the eligibility criteria. Four tables summarize their findings: study details (aim, population, interventions, comparisons, methods, and outcomes), data details (size, type, modalities, annotation, balance, availability, and language of study), methodology (pre-processing, feature generation, machine learning, evaluation, and results), and clinical applicability (research implications, clinical potential, risk of bias, and strengths/limitations). Conclusion: Promising results are reported across nearly all 51 studies, but very few have been implemented in clinical research or practice. The main limitations of the field are poor standardization, limited comparability of results, and a degree of disconnect between study aims and clinical applications. Active attempts to close these gaps will support translation of future research into clinical practice.


2016 ◽  
Vol 208 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Judith R. Harrison ◽  
Michael J. Owen

SummaryThe pathogenesis of Alzheimer's disease is complex. The amyloid hypothesis has directed research efforts for many years, but it has recently been questioned after failed drug trials. Here, we review the evidence for and against and suggest that it might be premature to abandon the amyloid hypothesis.


2013 ◽  
Vol 9 (4) ◽  
pp. 438-444 ◽  
Author(s):  
Bruno Vellas ◽  
Maria C. Carrillo ◽  
Cristina Sampaio ◽  
H. Robert Brashear ◽  
Eric Siemers ◽  
...  

1996 ◽  
Vol 9 (4) ◽  
pp. 176-180 ◽  
Author(s):  
Jason T. Olin ◽  
Lon S. Schneider ◽  
Rachelle S. Doody ◽  
Christopher M. Clark ◽  
Steven H. Ferris ◽  
...  

It is important that clinicians who rate global change as part of Alzheimer's disease (AD) clinical drug trials agree on a relevant set of behaviors and information to be considered in formulating their rating. Yet, consensus among raters has been difficult to establish, and inter-rater reliability of clinical global impression of change (CGIC) ratings has been low. In preparation for the development of a new CGIC scale to be used in AD clinical trials, the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC), we surveyed clinicians at sites comprising the National Institute on Aging-sponsored ADCS participating centers to identify whether or not consensus regarding CGICs exists. Overall, respondents reported that a CGIC should include an assessment of the patient's function and mental status, a care giver interview, and a standardized set of questions, and it should take approximately 20 minutes per interview. Depending on a patient's level of impairment, raters consider different areas of behavior in formulating a CGIC rating. These findings demonstrate the considerable consensus regarding the CGIC rating process, and were integrated into the design of the ADCS-CGIC, currently in use.


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