Relationship between the response to donepezil and plasma amyloid beta oligomers in patients with Alzheimer's disease

AIM

To date, there is no reported effective biomarker that can predict which Alzheimer's disease (AD) patients will respond to donepezil and which will not. This study aimed to investigate whether baseline values of Aβ oligomers (AβOs), measured by the Multimer Detection System-Oligomeric Aβ (MDS-OAβ), can be used to predict responders after 6 months of donepezil medication.

METHODS

The study enrolled 104 patients diagnosed with probable AD. After 6 months of donepezil medication, the response to treatment was evaluated by re-assessing the Korean version of the Mini-Mental State Examination (K-MMSE) and Clinical Dementia Rating scale-Sum of Box (CDR-SB) scales conducted at baseline. The patients were categorized into two groups according to the baseline MDS-OAβ values known as the cut-off for AD diagnosis: a group with values below 0.78 and another group with values equal to or above 0.78.

RESULTS

After 6 months of medication, the number of responders was 50 (49.5%). Responders exhibited significantly worse baseline CDR, CDR-SB, K-MMSE, and Barthel index compared with non-responders. There was a significantly higher number of responders among patients with MDS-OAβ values below the cut-off of 0.78 compared with those with values equal to or above this threshold. Furthermore, there was a significant improvement in the K-MMSE and CDR-SB after 6 months of donepezil medication in patients with MDS-OAβ values below 0.78 compared with those with values equal to or above 0.78.

CONCLUSIONS

Baseline MDS-OAβ values might constitute a novel biochemical marker for the efficacy of 6 months of donepezil treatment in AD. Geriatr Gerontol Int 2024; ••: ••-••.

Repetitive transcranial magnetic stimulation as a treatment for Alzheimer's disease: A randomized placebo-controlled double-blind clinical trial

We report results of a large multisite double-blind randomized trial investigating the short and long-term efficacy of repetitive transcranial magnetic stimulation (rTMS) applied to patients with Alzheimer's disease (AD) at mild to moderate stages, in doses of either 2 or 4 weeks of treatment (5 days/week), whilst compared with 4 weeks of sham rTMS. Randomization to treatment group was stratified based on age and severity. The objectives of this study were to: 1) investigate the efficacy of active rTMS versus sham, 2) investigate the effect of dose of treatment (2 or 4 weeks), and 3) investigate the length of benefits from treatment. The rTMS pulses (20 ​Hz, 30 pulses/train, 25 trains, 10-s intertrain interval) were applied serially to the left and right dorsolateral prefrontal cortex using neuro-navigation. We compared the primary outcome measure's (ADAS-Cog) score changes from pre- to post-treatment, with assessments at baseline and 4 more times up to 6 months post-treatment. Data of 135 patients were analyzed. The mean total ADAS-Cog score at baseline did not differ between the active and sham treatment groups, nor across the three study sites. The overall results show significant cognitive improvement after treatment up to two months post-treatment with either sham or active coils. The results show both short and long-term benefits of active rTMS treatment but also show similar benefits for sham coil treatment of mild/moderate AD. We discuss this finding in the context of the existing literature on rTMS therapy for AD, as well as evidence of the sham coil's potential to induce a low-level current in the brain. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02908815.

Repetitive TMS applied to the precuneus stabilizes cognitive status in Alzheimer’s disease

This scientific commentary refers to ‘Precuneus magnetic stimulation for Alzheimer's disease: a randomized, sham-controlled trial’ by Koch et al. (https://doi.org/10.1093/brain/awac285).

Predictors of response to acetylcholinesterase inhibitors in dementia: A systematic review

Background

The mainstay of therapy for many neurodegenerative dementias still relies on acetylcholinesterase inhibitors (AChEI); however, there is debate on various aspects of such treatment. A huge body of literature exists on possible predictors of response, but a comprehensive review is lacking. Therefore, our aim is to perform a systematic review of the predictors of response to AChEI in neurodegenerative dementias, providing a categorization and interpretation of the results.

Methods

We conducted a systematic review of the literature up to December 31st, 2021, searching five different databases and registers, including studies on rivastigmine, donepezil, and galantamine, with clearly defined criteria for the diagnosis of dementia and the response to AChEI therapy. Records were identified through the string: predict * AND respon * AND (acetylcholinesterase inhibitors OR donepezil OR rivastigmine OR galantamine). The results were presented narratively.

Results

We identified 1,994 records in five different databases; after exclusion of duplicates, title and abstract screening, and full-text retrieval, 122 studies were finally included.

Discussion

The studies show high heterogeneity in duration, response definition, drug dosage, and diagnostic criteria. Response to AChEI seems associated with correlates of cholinergic deficit (hallucinations, fluctuating cognition, substantia innominate atrophy) and preserved cholinergic neurons (faster alpha on REM sleep EEG, increased anterior frontal and parietal lobe perfusion after donepezil); white matter hyperintensities in the cholinergic pathways have shown inconsistent results. The K-variant of butyrylcholinesterase may correlate with better response in late stages of disease, while the role of polymorphisms in other genes involved in the cholinergic system is controversial. Factors related to drug availability may influence response; in particular, low serum albumin (for donepezil), CYP2D6 variants associated with reduced enzymatic activity and higher drug doses are the most consistent predictors, while AChEI concentration influence on clinical outcomes is debatable. Other predictors of response include faster disease progression, lower serum cholesterol, preserved medial temporal lobes, apathy, absence of concomitant diseases, and absence of antipsychotics. Short-term response may predict subsequent cognitive response, while higher education might correlate with short-term good response (months), and long-term poor response (years). Age, gender, baseline cognitive and functional levels, and APOE relationship with treatment outcome is controversial.

Repeated Transcranial Magnetic Stimulation for Improving Cognition in Patients With Alzheimer Disease: Protocol for a Randomized, Double-Blind, Placebo-Controlled Trial

Background

Alzheimer disease has no known cure. As existing pharmacologic interventions only modestly slow cognitive decline, there is a need for new treatments. Recent trials of repetitive transcranial magnetic stimulation (rTMS) have reported encouraging results for improving or stabilizing cognition in patients diagnosed with Alzheimer dementia. However, owing to small samples and lack of a well-controlled double-blind design, the results to date are inconclusive. This paper presents the protocol for a large placebo-controlled double-blind study designed with sufficient statistical rigor to measure the efficacy of rTMS treatment in patients with Alzheimer dementia.

Objective

The objectives are to (1) recruit and enroll up to 200 eligible participants, (2) estimate the difference in treatment effects between active treatment and sham treatment, (3) estimate the difference in treatment effects between two doses of rTMS applications, (4) estimate the duration of treatment effects among responders to active rTMS treatment, and (5) estimate the effect of dementia severity on treatment outcomes among patients receiving active rTMS treatment.

Methods

We have designed our study to be a double-blind, randomized, placebo-controlled clinical trial investigating the short- and long-term (up to 6 months) benefits of active rTMS treatment at two doses (10 sessions over 2 weeks and 20 sessions over 4 weeks) compared with sham rTMS treatment. The study will include patients aged ≥55 years who are diagnosed with Alzheimer disease at an early to moderate stage and have no history of seizures and no major depression. The primary outcome measure is the change in the Alzheimer Disease Assessment Scale-Cognitive Subscale score from pretreatment to posttreatment. Secondary outcomes are changes in performance on tests of frontal lobe functioning (Stroop test and verbal fluency), changes in neuropsychiatric symptoms (Neuropsychiatric Inventory Questionnaire), and changes in activities of daily living (Alzheimer Disease Co-operative Study-Activities of Daily Living Inventory). Tolerability of the intervention will be assessed using a modification of the Treatment Satisfaction Questionnaire for Medication. We assess participants at baseline and 3, 5, 8, 16, and 24 weeks after the intervention.

Results

As of November 1, 2020, we have screened 523 individuals, out of which 133 were eligible and have been enrolled. Out of the 133 individuals, 104 have completed the study. Moreover, as of November 1, 2020, there has been no serious adverse event. We anticipate that rTMS will considerably improve cognitive function, with effects lasting up to 3 months. Moreover, we expect rTMS to be a well-tolerated treatment with no serious side effect.

Conclusions

This protocol design will allow to address both the rTMS active treatment dose and its short- and long-term effects compared with sham treatment in large samples.

Trial Registration

ClinicalTrials.gov NCT02908815; https://clinicaltrials.gov/ct2/show/NCT02908815

International Registered Report Identifier (IRRID)

DERR1-10.2196/25144

CHRFAM7A: A human specific fusion gene, accounts for the translational gap for cholinergic strategies in Alzheimer's disease

Background

Cholinergic neuronal loss is one of the hallmarks of AD related neurodegeneration; however, preclinical promise of α7 nAChR drugs failed to translate into humans. CHRFAM7A, a uniquely human fusion gene, is a negative regulator of α7 nAChR and was unaccounted for in preclinical models.

Methods

Molecular methods: Function of CHRFAM7A alleles was studied in vitro in two disease relevant phenotypic readouts: electrophysiology and Aβ uptake. Genome edited human induced pluripotent stem cells (iPSC) were used as a model system with the human context. Double blind pharmacogenetic study: We performed double-blind pharmacogenetic analysis on the effect of AChEI therapy based on CHRFAM7A carrier status in two paradigms: response to drug initiation and DMT effect. Mini Mental Status Examination (MMSE) was used as outcome measure. Change in MMSE score from baseline was compared by 2-tailed T-test. Longitudinal analysis of clinical outcome (MMSE) was performed using a fitted general linear model, based on an assumed autoregressive covariance structure. Model independent variables included age, sex, and medication regimen at the time of the first utilized outcome measure (AChEI alone or AChEI plus memantine), APOE4 carrier status (0, 1 or 2 alleles as categorical variables) and CHRFAM7A genotype.

Findings

The direct and inverted alleles have distinct phenotypes. Functional CHRFAM7A allele classifies the population as 25% non-carriers and 75% carriers. Induced pluripotent stem cell (iPSC) models α7 nAChR mediated Aβ neurotoxicity. Pharmacological readout translates into both first exposure (p = 0.037) and disease modifying effect (p = 0.0048) in two double blind pharmacogenetic studies.

Interpretation

CHRFAM7A accounts for the translational gap in cholinergic strategies in AD. Clinical trials not accounting for this uniquely human genetic factor may have rejected drug candidates that would benefit 25% of AD. Reanalyses of the completed trials using this pharmacogenetic paradigm may identify effective therapy.

Funding:

Responder Analysis of a Multicomponent Non-Pharmacological Intervention (MAKS) for People With Cognitive Impairment in the German Day-Care Study (DeTaMAKS)

Background: Multicomponent non-pharmacological therapies have been shown to be effective at reducing cognitive symptoms and slowing deterioration in abilities to perform activities of daily living (ADL) in individuals with cognitive impairment. However, little is known about response rates and predictors of response. Methods: We used data from the German day-care study (DeTaMAKS; De = dementia, Ta = Tagespflege/day-care, M = motor stimulation, A = activities of daily living stimulation, K = k/cognitive stimulation, S = social stimulation; n = 362), which was based on a cluster-randomized trial of the non-pharmacological, multicomponent, anti-dementia MAKS therapy for people with cognitive impairment in day-care centers. We investigated response (defined as improvement or no deterioration) for three different response criteria: cognition via Mini-Mental State Examination (MMSE) score, ADL via Erlangen Test of Activities of Daily Living in Persons with Mild Dementia or Mild Cognitive Impairment (ETAM) score, and behavioral and psychological symptoms of dementia (BPSD) via Neuropsychiatric Inventory Questionnaire (NPI-Q) score. In addition, we calculated the number needed to treat (NTT) and response rates according to net gain analyses. Results: For all three criteria, the response rates were higher in the intervention group than in the control group (chi2 test: p = 0.058 to p = 0.003). Compared with non-responders, responders according to cognition had higher ETAM scores (= better ADL abilities) at baseline; responders according to ADL had lower ETAM scores (= poorer ADL abilities) at baseline; and responders according to BPSD had higher NPI-Q scores (= more BPSD) at baseline. Classification rates based on these predictors ranged from 60.6 to 68.3%. Discussion: The response rates to the non-pharmacological MAKS therapy were greater than those reported for anti-dementia drugs. There were only a few differences between responders and non-responders. Because of the low classification rates, these variables had only a small impact on response predictions. Therefore, there are no empirically substantiated selection criteria for the application of MAKS therapy in facilities. Clinical Trial Registration: www.ClinicalTrials.gov, identifier ISRCTN16412551.

Prediction of Treatment Response to Donepezil using Automated Hippocampal Subfields Volumes Segmentation in Patients with Mild Alzheimer's Disease

Previous studies reported some relationships between donepezil treatment and hippocampus in Alzheimer's disease (AD). However, due to methodological limitations, their close relationships remain unclear. The aim of this study is to predict treatment response to donepezil by utilizing the automated segmentation of hippocampal subfields volumes (ASHS) in AD. Sixty four AD patients were prescribed with donepezil and were followed up for 24 weeks. Cognitive function was measured to assess whether there was a response from the donepezil treatment. ASHS was implemented on non-responder (NR) and responder (TR) groups, and receiver operator characteristic (ROC) analysis was conducted to evaluate the sensitivity, specificity, and accuracy of hippocampal subfields in predicting response to donepezil. The left total hippocampus and the CA1 area of the NR were significantly smaller than those of the TR group. The ROC curve analysis showed the left CA1 volumes showed highest area under curve (AUC) of 0.85 with a sensitivity of 88.0%, a specificity of 74.0% in predicting treatment response to donepezil treatment. We expect that hippocampal subfields volume measurements that predict treatment responses to current AD drugs will enable more evidence-based, individualized prescription of medications that will lead to more favorable treatment outcomes.

Donepezil Plus Solifenacin (CPC-201) Treatment for Alzheimer's Disease

Available cholinergic drugs for treating Alzheimer's disease (AD) provide modest symptomatic benefit. We hypothesized that co-administration of a peripheral anticholinergic to reduce dose-limiting adverse effects (AEs) would enable the safe/tolerable use of higher cholinesterase inhibitor doses and thus improve their antidementia efficacy. A modified single-blind, ascending-dose, phase IIa study of donepezil plus solifenacin (CPC-201) lasting 26 weeks was conducted in 41 patients with probable AD of moderate severity. Entry criteria included the use of donepezil at a dose of 10 mg/day during the preceding 3 months. The primary outcome measure was the maximum tolerated dose (MTD) of donepezil achieved (to protocol limit of 40 mg/day) when administered with the anticholinergic solifenacin 15 mg/day. Secondary measures included assessments of cognitive and global function, as well as of AEs. The mean ± SD donepezil MTD increased to 38 ± 0.74 mg/day (median 40 mg/day; p < 0.001); 88% of the study population safely attained this dose at the end of titration. Markedly reduced donepezil AE frequency, especially gastrointestinal, allowed this dose increase. There were no drug-related serious AEs or clinically significant laboratory abnormalities. At 26 weeks, Alzheimer's Disease Assessment Scale Cognitive Component scores in the efficacy evaluable population improved by 0.35 ± 0.85 points over baseline (p < 0.05), an estimated 2.5 ± 0.84 points above 10 mg/day donepezil and 5.4 ± 0.84 points above historic placebo (both p < 0.05). Clinical Global Impression of Improvement scores improved by 0.94 ± 0.20 to 3.1 ± 0.20 points (p < 0.001). The findings suggest that limiting donepezil AEs by co-administration of solifenacin allows the safe administration of substantially higher cholinesterase inhibitors doses that may augment cognitive and global benefits in patients with AD.

Cilostazol as an add-on therapy for patients with Alzheimer's disease in Taiwan: a case control study

Background

Combination therapy using acetylcholinesterase inhibitors (AChEIs) and cilostazol is of unknown efficacy for patients with Alzheimer’s disease (AD).

Methods

We explored the therapeutic responses by using a case–control study, which was conducted in Taiwan. We enrolled 30 participants with stable AD who were receiving cilostazol (50 mg) twice per day as an add-on therapy combined with AChEIs, and 30 participants as controls who were not receiving cilostazol as an add-on therapy. The therapeutic responses were measured using neuropsychological assessments and analyzed in relation to cilostazol use, apolipoprotein E genotype, and demographic characteristics. Mini-mental state examination (MMSE) and clinical dementia rating sum of boxes (CDR-SB) were administered at the outset of the study and 12 months later. Multiple logistic regression analysis was used to estimate the association between the therapeutic response and cilostazol use.

Results

For the therapeutic indicator of cognition, Cilostazol use (adjusted odds ratio (aOR) = 0.17, 95% confidence interval (CI) = 0.03–0.80), initial CDR-SB score (aOR = 2.06, 95% CI = 1.31–3.72), and initial MMSE score (aOR = 1.41, 95% CI = 1.11–1.90), but not age, sex, education, or ApoE ε4 status, were significantly associated with poor therapeutic outcomes. For the therapeutic indicator of global status, no significant association was observed between the covariates and poor therapeutic outcomes.

Conclusions

Cilostazol may reduce the decline of cognitive function in stable AD patients when applied as an add-on therapy.

Effect of Korean Red Ginseng on Cognitive Function and Quantitative EEG in Patients with Alzheimer's Disease: A Preliminary Study

BACKGROUND

Korean red ginseng (KRG) has a nootropic effect. This study assessed the efficacy of KRG on cognitive function and quantitative electroencephalography (EEG) in patients with Alzheimer's disease (AD).

METHODS

Fourteen patients with AD (mean age, 74.93 years; 11 women and 3 men) were recruited and treated with KRG (4.5 g per day) for 12 weeks. Cognitive function was assessed by the Korean Mini-Mental State Examination (K-MMSE) and the Frontal Assessment Battery (FAB). EEG performed before and after treatment were analyzed with quantitative spectral analysis.

RESULTS

The FAB score improved significantly after 12 weeks of treatment. In the relative power spectrum analysis performed according to responsiveness, alpha power increased significantly in the right temporal area of the responders. The increments of relative alpha power in the right temporal, parietal, and occipital areas were significantly higher in the responders than the nonresponders.

CONCLUSIONS

This study indicates the efficacy of KRG on frontal lobe function in AD, related to increasing relative alpha power.

Normal Hearing Ability but Impaired Auditory Selective Attention Associated with Prediction of Response to Donepezil in Patients with Alzheimer's Disease

Background. Alzheimer's disease (AD) patients have a poor response to the voices of caregivers. After administration of donepezil, caregivers often find that patients respond more frequently, whereas they had previously pretended to be “deaf.” We investigated whether auditory selective attention is associated with response to donepezil. Methods. The subjects were40 AD patients, 20 elderly healthy controls (HCs), and 15 young HCs. Pure tone audiometry was conducted and an original Auditory Selective Attention (ASA) test was performed with a MoCA vigilance test. Reassessment of the AD group was performed after donepezil treatment for 3 months. Results. Hearing level of the AD group was the same as that of the elderly HC group. However, ASA test scores decreased in the AD group and were correlated with the vigilance test scores. Donepezil responders (MMSE 3+) also showed improvement on the ASA test. At baseline, the responders had higher vigilance and lower ASA test scores. Conclusion. Contrary to the common view, AD patients had a similar level of hearing ability to healthy elderly. Auditory attention was impaired in AD patients, which suggests that unnecessary sounds should be avoided in nursing homes. Auditory selective attention is associated with response to donepezil in AD.

Short and Long-term Effects of rTMS Treatment on Alzheimer's Disease at Different Stages: A Pilot Study

Repetitive transcranial magnetic stimulation (rTMS) uses a magnetic coil to induce an electric field in brain tissue. As a pilot study, we investigated the effect of rTMS treatment on 10 volunteers with Alzheimer’s disease (AD) in a two-stage study. The first stage consisted of a double-blind crossover study with real and sham treatments. Each treatment block consisted of 13 sessions over 4 weeks. During each session, 2000 TMS pulses at 90%–100% of resting motor threshold were applied to dorsolateral prefrontal cortex bilaterally, and the patients were kept cognitively active by object/action naming during the treatment. The second stage was an open-label study, in which the same treatments were performed in 2-week blocks (10 sessions) approximately every 3 months as follow-up treatments on six of the volunteers, who completed the first stage of the study. Primary outcome measures were the Montreal Cognitive Assessment (MOCA) and the Alzheimer’s Disease Assessment Scale-cognitive subscale. The secondary outcome measures were the Revised Memory and Behavior Checklist as well as our team’s custom-designed cognitive assessments. The results showed a noticeably stronger improvement on all assessments during the real treatment as compared to the sham treatment. The changes in MOCA scores as well as our designed cognitive assessment were found to be statistically significant, with particularly strong results in the six volunteers who were in the early stages of the disease. The long-term trends observed in the second stage of the study also showed generally less decline than would be expected for their condition. It appears that rTMS can be an effective tool for improving the cognitive abilities of patients with early to moderate stages of AD. However, the positive effects of rTMS may persist for only up to a few weeks. Specific skills being practiced during rTMS treatment may retain their improvement for longer periods.

Evaluating Response to High-Dose 13.3 mg/24 h Rivastigmine Patch in Patients with Severe Alzheimer's Disease

AIMS

To identify factors predicting improvement/stabilization on the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) and investigate whether early treatment responses can predict long-term outcomes, during a trial of 13.3 mg/24 h versus 4.6 mg/24 h rivastigmine patch in patients with severe Alzheimer's disease (AD).

METHODS

Logistic regression was used to relate Week 24 ADCS-CGIC score to potential baseline predictors. Additional analyses based on receiver-operating characteristic curves were performed using Week 8/16 ADCS-CGIC scores to predict response (13.3 mg/24 h patch) at Week 24. ADCS-CGIC score of (1) 1-3 = "improvement," (2) 1-4 = "improvement or no change".

RESULTS

"Treatment" (13.3 mg/24 h patch) and increased age were significant predictors of "improvement" (P = 0.01 and P = 0.003, respectively), and "treatment" (P = 0.001), increased age (P = 0.002), and prior AD treatment (P = 0.03) for "improvement or no change". At Week 8 and 16, ADCS-CGIC scores of 4 and 5 were optimal thresholds in predicting "improvement," and "improvement or no change," respectively, at Week 24.

CONCLUSIONS

A significant therapeutic effect of high-dose rivastigmine patch on ADCS-CGIC response was observed. The 13.3 mg/24 h patch was identified as a predictor of "improvement" or "improvement or no change". Patients with minimal worsening/improvement/no change after treatment initiation may be more likely to respond following long-term therapy.

Responder analysis of a randomized comparison of the 13.3 mg/24 h and 9.5 mg/24 h rivastigmine patch

INTRODUCTION

OPtimizing Transdermal Exelon In Mild-to-moderate Alzheimer's disease (OPTIMA) was a randomized, double-blind comparison of 13.3 mg/24 h versus 9.5 mg/24 h rivastigmine patch in patients with mild-to-moderate Alzheimer's disease who declined despite open-label treatment with 9.5 mg/24 h patch. Over 48 weeks of double-blind treatment, high-dose patch produced greater functional and cognitive benefits compared with 9.5 mg/24 h patch.

METHODS

Using OPTIMA data, a post-hoc responder analysis was performed to firstly, compare the proportion of patients demonstrating improvement or absence of decline with 13.3 mg/24 h versus 9.5 mg/24 h patch; and secondly, identify predictors of improvement or absence of decline. 'Improvers' were patients who improved on the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) by ≥4 points from baseline, and did not decline on the instrumental domain of the Alzheimer's Disease Cooperative Study-Activities of Daily Living scale (ADCS-IADL). 'Non-decliners' were patients who did not decline on either scale.

RESULTS

Overall, 265 patients randomized to 13.3 mg/24 h and 271 to 9.5 mg/24 h patch met the criteria for inclusion in the intention-to-treat population and were included in the analyses. Significantly more patients were 'improvers' with 13.3 mg/24 h compared with 9.5 mg/24 h patch at Weeks 24 (44 (16.6%) versus 19 (7.0%); P < 0.001) and 48 (21 (7.9%) versus 10 (3.7%); P = 0.023). A significantly greater proportion of patients were 'non-decliners' with 13.3 mg/24 h compared with 9.5 mg/24 h patch at Week 24 (71 (26.8%) versus 44 (16.2%); P = 0.002). At Week 48, there was a trend in favor of 13.3 mg/24 h patch. Functional and cognitive assessment scores at double-blind baseline did not consistently predict effects at Weeks 24 or 48.

CONCLUSION

More patients with mild-to-moderate Alzheimer's disease who are titrated to 13.3 mg/24 h rivastigmine patch at time of decline are 'improvers' or 'non-decliners' i.e. show responses on cognition and activities of daily living compared with patients remaining on 9.5 mg/24 h patch.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00506415; registered July 20, 2007.

Effect of APOE and CHRNA7 genotypes on the cognitive response to cholinesterase inhibitor treatment at different stages of Alzheimer's disease

The loss of cholinergic transmission is considered to be an important cause of Alzheimer's disease (AD). Treatment with acetyl cholinesterase inhibitors (ChEIs) shows benefits; however, great heterogeneity has been observed in patient responses. We evaluated apolipoprotein E (APOE) and α7 nicotinic receptor (CHRNA7) single-nucleotide polymorphisms (SNPs) and associated these SNPs with pharmacological responses to ChEIs in a Brazilian population with AD. We studied 177 outpatients using ChEIs, and they were classified as responders and nonresponders according to variation in Mini-Mental State Examination (MMSE) status. The analysis of APOE genotypes showed that patients with the ε4 allele had a worse response than those without the ε4 allele. We observed an association between the CHRNA7 T allele and a better response to treatment with ChEIs in patients with mild AD (MMSE ≥ 20). The SNP rs6494223 of CHRNA7 as well as APOEε4 could be useful for understanding the response to ChEI treatment in patients with AD.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of Alzheimer's disease and other dementias

OBJECTIVES

To define a practice guideline for biological treatment of dementia and to make transparent the development of the guideline connecting the original data with the resulting recommendations.

METHODS

This guideline includes pharmacologic treatment considerations for patients with Alzheimer's disease, vascular dementia, DLB, and fronto-temporal dementia. Studies were selected that represent double-blind placebo-controlled trials of at least 3 months duration in patients with a diagnosis of dementia according to accepted international diagnostic criteria (for example the NINCDS/ADRDA or NINDS/AIREN criteria). Moreover, to be included studies had to fulfill a restrictive set of methodological criteria. Original studies and not meta-analyses determined the evaluation and the development of recommendations.

RESULTS

Antidementia pharmaceuticals neither cure nor arrest the disease. A modest effect of improvement of symptoms compared with placebo can be observed. Antidementia pharmaceuticals show different efficacy and side effect profiles. The type of dementia, the individual symptom constellation and the tolerability should determine what medication should be used. There are hints that combination therapy of drugs with different therapeutic mechanisms might improve the efficacy. In treating neuropsychiatric symptoms (NPS), psychosocial intervention should be the treatment of first choice. Pharmaceuticals can only be recommended when psychosocial interventions is not adequate. However, even then the side effects of pharmaceuticals limit their use.

CONCLUSIONS

Depending on the diagnostic entity and the pathology treated different anti-dementia drugs can be recommended to improve symptoms. In the management of NPS, side effects limit the use of medications even when psychosocial interventions have failed. Thus, there is an urgent need to develop more efficacious medications for the treatment of dementia.

Efficacy of a medical food in mild Alzheimer's disease: A randomized, controlled trial

OBJECTIVE

To investigate the effect of a medical food on cognitive function in people with mild Alzheimer's disease (AD).

METHODS

A total of 225 drug-naïve AD patients participated in this randomized, double-blind controlled trial. Patients were randomized to active product, Souvenaid, or a control drink, taken once-daily for 12 weeks. Primary outcome measures were the delayed verbal recall task of the Wechsler Memory Scale-revised, and the 13-item modified Alzheimer's Disease Assessment Scale-cognitive subscale at week 12.

RESULTS

At 12 weeks, significant improvement in the delayed verbal recall task was noted in the active group compared with control (P = .021). Modified Alzheimer's Disease Assessment Scale-cognitive subscale and other outcome scores (e.g., Clinician Interview Based Impression of Change plus Caregiver Input, 12-item Neuropsychiatric Inventory, Alzheimer's disease Co-operative Study-Activities of Daily Living, Quality of Life in Alzheimer's Disease) were unchanged. The control group neither deteriorated nor improved. Compliance was excellent (95%) and the product was well tolerated.

CONCLUSIONS

Supplementation with a medical food including phosphatide precursors and cofactors for 12 weeks improved memory (delayed verbal recall) in mild AD patients. This proof-of-concept study justifies further clinical trials.

The ADAS-cog and clinically meaningful change in the VISTA clinical trial of galantamine for Alzheimer's disease

BACKGROUND

A minimum 4-point change at 6 months on the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) is deemed clinically important, but this cut-point has been little studied in relation to clinical meaningfulness. In an investigator-initiated, clinical trial of galantamine, we investigated the extent to which a 4-point change classifies goal attainment by individual patients.

METHODS

Secondary analysis of the video imaging synthesis of treating Alzheimer's disease (VISTA) study: a 4-month, multi-centre, parallel-group, double-blind, placebo-controlled, trial of galantamine in 130 mild-moderate Alzheimer's disease patients (4-month open-label follow-up). ADAS-cog responses at 6 months were compared with outcomes on three clinical measures: clinician's interview based impression of change-plus caregiver input (CIBIC+), patient/carer-goal attainment scaling (PGAS) and clinician-GAS (CGAS).

RESULTS

Thirty-seven of 99 patients improved by > or = 4 points on the ADAS-cog at 6 months, and 16/99 showed > or = 4-point worsening. ADAS-cog change scores correlated notionally to modestly with changes on the CGAS (r = -0.31), the PGAS (r = -0.29) and the CIBIC+ (r = 0.31). As a group, patients with ADAS-cog improvement were significantly more likely to improve on the clinical measures; those who worsened showed non-significant clinical decline. Individually, about half were misclassified in relation to each clinical measure; often when the ADAS-Cog detected 'no change', clinically meaningful effects could be detected. Even so, no ADAS-Cog cut-point optimally classified patients' clinical responses.

CONCLUSION

A 4-point ADAS-cog change at 6 months is clinically meaningful for groups. Substantial individual misclassification between the ADAS-cog and clinical measures suggests no inherent meaning to a 4-point ADAS-cog change for a given patient.

Effectiveness of donepezil in reducing clinical worsening in patients with mild-to-moderate alzheimer's disease

BACKGROUND

Therapeutic endpoints based on reduced clinical worsening represent clinically relevant and realistic goals for patients suffering from progressive neurodegenerative disorders such as Alzheimer's disease (AD).

METHODS

Data from 906 patients (388 receiving placebo; 518 receiving donepezil) with mild-to-moderate AD [Mini-Mental State Examination (MMSE) score 10-27] were pooled from 3 randomized, double-blind placebo-controlled studies. Clinical worsening was defined as decline in (1) cognition (MMSE), (2) cognition and global ratings (Clinician's Interview-Based Impression of Change plus Caregiver Input/Gottfries-Bråne-Steen scale) or (3) cognition, global ratings and function (various functional measures).

RESULTS

At week 24, lower percentages of donepezil-treated patients than placebo patients met the criteria for clinical worsening, regardless of the definition. The odds of declining were significantly reduced for donepezil-treated versus placebo patients (p < 0.0001; all definitions). Among patients meeting criteria for clinical worsening, mean declines in MMSE scores were greater for placebo than donepezil-treated patients.

CONCLUSION

In this population, donepezil treatment was associated with reduced odds of clinical worsening of AD symptoms. Moreover, patients worsening on donepezil were likely to experience less cognitive decline than expected if left untreated. This suggests that AD patients showing clinical worsening on donepezil may still derive benefits compared with placebo/untreated patients.