Translation from Preclinical Research to Clinical Trials: Brain-Gut Photobiomodulation Therapy for Alzheimer's Disease.

Recently, novel non-pharmacological interventions, such as photobiomodulation (PBM) therapy, have shown promise for the treatment of Alzheimer's disease (AD). This article outlines the translation from the preclinical to clinical stages of an innovative brain-gut PBM therapy in a mouse model of AD, a pilot clinical trial involving mild-to-moderate AD patients, and a continuing pivotal clinical trial with a similar patient population. In a mouse model of AD (Aß25-35), daily application of brain-gut PBM therapy to both the head and the abdomen produced a neuroprotective effect against the neurotoxic effects of an Aß25-35 peptide injection by normalizing all the modified behavioral and biochemical parameters. The pilot clinical trial to evaluate brain-gut PBM therapy demonstrated the tolerability and feasibility of the novel PBM-based treatment for mild-to-moderate AD patients. Compared to the sham patients, the PBM-treated patients had lower Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) comprehension sub-scores, higher forward verbal spans, and lower Trail Making Test (TMT) Part B (TMT-B) execution times, which suggest an improvement in cognitive functions. This pilot study provided important information for the design of a novel pivotal clinical trial, currently in progress, to assess the efficacy of brain-gut PBM therapy in a larger sample of AD patients. This pivotal clinical trial could demonstrate that brain-gut PBM therapy is a safe, well-tolerated, and efficient disease-modifying treatment for mild-to-moderate AD patients and that it has medical and economic benefits.

Cognitive impact of multidomain intervention and omega 3 according to blood Aß42/40 ratio: a subgroup analysis from the randomized MAPT trial.

BACKGROUND: In MAPT (Multidomain Alzheimer Preventive Trial), a cognitive effect of multidomain intervention (MI) was showed in non-demented subjects with positive amyloid PET. However, screening eligible patients for multidomain intervention by PET is difficult to generalize in real-world settings. METHODS: MAPT study was a 3-year, randomized, placebo-controlled trial followed by a 2-year observational and optional extension. All participants were non-demented and randomly assigned (1:1:1:1) to the MI plus omega 3, MI plus placebo, omega 3 alone, or placebo alone group. The objectives were to assess the cognitive effect of MAPT interventions (omega 3 supplementation, MI, combined intervention) in non-demented subjects according to amyloid blood status at 12, 36, and 60 months. In this subgroup analysis (n = 483), amyloid status was defined by plasma Aß42/40 ratio (cutoff ≤ 0.0107). The primary outcome measure was the change in cognitive composite score after a 1, 3, and 5-year clinical follow-up. RESULTS: The intention-to-treat (ITT) population included 483 subjects (161 positive and 322 negative amyloid participants based on plasma Aß42/40 ratio). In the positive amyloid ITT population, we showed a positive effect of MI plus omega 3 on the change in composite cognitive score in 12 (raw p = .0350, 0.01917, 95% CI = [0.0136 to 0.3699]) and 36 months (raw p = .0357, 0.2818, 95% CI = [0.0190 to 0.5446]). After correction of multiple comparisons and adjustments, these differences were not significant (adjusted p = .1144 and .0690). In the per-protocol positive amyloid group (n = 154), we observed a significant difference between the combined intervention and placebo groups at 12 (p = .0313, 0.2424, 0.0571 to 0.4276) and 36 months (p = .0195, 0.3747, 0.1055 to 0.6439) persisting after adjustment. In the ITT and per-protocol analyses, no cognitive effect was observed in the positive and negative amyloid group at 60-month visit. CONCLUSIONS: These findings suggest a benefit of MI plus omega 3 in positive blood amyloid subjects. This promising trend needs to be confirmed before using blood biomarkers for screening in preventive trials. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01513252 .

Associations of erythrocyte omega-3 fatty acids with cognition, brain imaging and biomarkers in the Alzheimer's disease neuroimaging initiative: cross-sectional and longitudinal retrospective analyses.

BACKGROUND: The association between omega-3 (ω-3) PUFAs and cognition, brain imaging and biomarkers is still not fully established. OBJECTIVES: The aim was to analyze the cross-sectional and retrospective longitudinal associations between erythrocyte ω-3 index and cognition, brain imaging, and biomarkers among older adults. METHODS: A total of 832 Alzheimer's Disease Neuroimaging Initiative 3 (ADNI-3) participants, with a mean (SD) age of 74.0 (7.9) y, 50.8% female, 55.9% cognitively normal, 32.7% with mild cognitive impairment, and 11.4% with Alzheimer disease (AD) were included. A low ω-3 index (%EPA + %DHA) was defined as the lowest quartile (≤3.70%). Cognitive tests [composite score, AD Assessment Scale Cognitive (ADAS-Cog), Wechsler Memory Scale (WMS), Trail Making Test, Category Fluency, Mini-Mental State Examination, Montreal Cognitive Assessment] and brain variables [hippocampal volume, white matter hyperintensities (WMHs), positron emission tomography (PET) amyloid-ß (Aß) and tau] were considered as outcomes in regression models. RESULTS: Low ω-3 index was not associated with cognition, hippocampal, and WMH volume or brain Aß and tau after adjustment for demographics, ApoEε4, cardiovascular disease, BMI, and total intracranial volume in the cross-sectional analysis. In the retrospective analysis, low ω-3 index was associated with greater Aß accumulation (adjusted ß = 0.02; 95% CI: 0.01, 0.03; P = 0.003). The composite cognitive score did not differ between groups; however, low ω-3 index was significantly associated with greater WMS-delayed recall cognitive decline (adjusted ß = -1.18; 95% CI: -2.16, -0.19; P = 0.019), but unexpectedly lower total ADAS-Cog cognitive decline. Low ω-3 index was cross-sectionally associated with lower WMS performance (adjusted ß = -1.81, SE = 0.73, P = 0.014) and higher tau accumulation among ApoE ε4 carriers. CONCLUSIONS: Longitudinally, low ω-3 index was associated with greater Aß accumulation and WMS cognitive decline but unexpectedly with lower total ADAS-Cog cognitive decline. Although no associations were cross-sectionally found in the whole population, low ω-3 index was associated with lower WMS cognition and higher tau accumulation among ApoE ε4 carriers. The Alzheimer's Disease Neuroimaging Initiative (ADNI) is registered at clinicaltrials.gov as NCT00106899.

The impact of a multi-domain intervention on cerebral glucose metabolism: analysis from the randomized ancillary FDG PET MAPT trial.

BACKGROUND: The Multidomain Alzheimer Preventive Trial (MAPT) was designed to assess the efficacy of omega-3 fatty acid supplementation, multidomain intervention (MI), or a combination of both on cognition. Although the MAPT study was negative, an effect of MI in maintaining cognitive functions compared to placebo group was showed in positive amyloid subjects. A FDG PET study (MAPT-NI) was implemented to test the impact of MI on brain glucose metabolism. METHODS: MAPT-NI was a randomized, controlled parallel-group single-center study, exploring the effect of MI on brain glucose metabolism. Participants were non-demented and had memory complaints, limitation in one instrumental activity of daily living, or slow gait. Participants were randomly assigned (1:1) to "MI group" or "No MI group." The MI consisted of group sessions focusing on 3 domains: cognitive stimulation, physical activity, nutrition, and a preventive consultation. [18F]FDG PET scans were performed at baseline, 6 months, and 12 months, and cerebral magnetic resonance imaging scans at baseline. The primary objective was to evaluate the MI effect on brain glucose metabolism assessed by [18F]FDG PET imaging at 6 months. The primary outcome was the quantification of regional metabolism rate for glucose in cerebral regions involved early in Alzheimer disease by relative semi-quantitative SUVr (FDG-based AD biomarker). An exploratory voxel-wise analysis was performed to assess the effect of MI on brain glucose metabolism without anatomical hypothesis. RESULTS: The intention-to-treat population included 67 subjects (34 in the MI group and 33 in the No MI group. No significant MI effect was observed on primary outcome at 6 months. In the exploratory voxel-wise analysis, we observed a difference in favor of MI group on the change of cerebral glucose metabolism in limbic lobe (right hippocampus, right posterior cingulate, left posterior parahippocampal gyrus) at 6 months. CONCLUSIONS: MI failed to show an effect on metabolism in FDG-based AD biomarker, but exploratory analysis suggested positive effect on limbic system metabolism. This finding could suggest a delay effect of MI on AD progression. TRIAL REGISTRATION: ClinicalTrials.gov Identifier, NCT01513252 .

Multidomain intervention and/or omega-3 in nondemented elderly subjects according to amyloid status.

INTRODUCTION: The Multidomain Alzheimer Preventive Trial (MAPT) assessed the efficacy of omega-3 fatty acid supplementation, a multidomain intervention (MI), or a combination of both on cognition. Impact according to cerebral amyloid status was evaluated by PET scan. METHODS: Participants were nondemented and had memory complaints, limitation in one instrumental activity of daily living, or slow gait. The primary outcome was a change from baseline in 36 months measured with a cognitive composite Z score. RESULTS: No effect was observed on cognition in the negative amyloid group (n = 167). In the positive amyloid group (n = 102), we observed a difference of 0.708 and 0.471 in the cognitive composite score between the MI plus omega-3 fatty acid group, the MI alone group, and the placebo group, respectively. DISCUSSION: MI alone or in combination with omega-3 fatty acids was associated with improved primary cognitive outcome in subjects with positive amyloid status. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01513252.

Memory Complaints and Cognitive Decline: Data from the GUIDAGE Study1.

BACKGROUND: Subjective cognitive decline (SCD) may be a very early symptom of Alzheimer's disease (AD) and may be associated with a cognitive decline in a cognitively normal population. The McNair and Kahn Scale was used to assess memory complaints in the GuidAge study. OBJECTIVE: Our objectives were to examine if the McNair and Kahn Scale can predict cognitive decline and to screen which (if any) of the question(s) of this scale would better predict this cognitive decline. METHODS: The GuidAge study was a phase III, multicenter, randomized, double blind, placebo-controlled study. Individuals aged 70 years and older, without cognitive impairment (Clinical Dementia Rate (CDR = 0)) at baseline who had spontaneously reported SCD were included in this study. The 20-item version of the McNair and Kahn Scale was used to assess SCD and a standardized neuropsychological assessment was used to assess the cognitive status. RESULTS: 1,307 patients with SCD and with CDR = 0 at baseline were included. During the 5 years of follow-up, 519 patients showed cognitive decline. Incidence of aggravation score of CDR was 13.40% person years (95% CI [12.24-14.56]). Results showed a significant relationship between the McNair and Kahn Scale score and decline in cognitive performance (HR 1.012; 95% CI [1.002-1.021]; p = 0.0156). Among the 20 items, 5 were statistically significant to predict cognitive decline after adjustment. CONCLUSION: SCD is a promising indicator of memory impairment. Our study found that using the McNair and Kahn scale can predict cognitive decline. A 5-item version of this scale could be used to screen patients in clinical practice and in clinical research.

'Clinical trials in Alzheimer's disease': immunotherapy approaches.

Recent advances in the understanding of Alzheimer's disease pathogenesis have led to the development of numerous compounds that might modify the disease process. Amyloid ß (Aß) peptide represents an important molecular target for intervention in Alzheimer's disease. Several types of Aß peptide immunotherapy for Alzheimer's disease are under investigation, direct immunization with synthetic intact Aß(42) , active immunization involving the administration of synthetic fragments of Aß peptide conjugated to a carrier protein and passive administration with monoclonal antibodies directed against Aß peptide. Pre-clinical studies showed that immunization against Aß peptide can provide protection and reversal of the pathology of Alzheimer's disease in animal models. Indeed, several adverse events have been described like meningoencephalitis with AN1792, vasogenic edema and microhemorrhages with bapineuzumab. Although immunotherapy approaches resulted in clearance of amyloid plaques in patients with Alzheimer's disease, this clearance did not show significant cognitive effect for the moment. Currently, several Aß peptide immunotherapy approaches are under investigation but also against tau pathology.