Bengt Winblad

Donepezil in patients with severe Alzheimer's disease: double-blind, parallel-group, placebo-controlled study

BACKGROUNDnThe cholinesterase inhibitor donepezil is used to treat mild-to-moderate Alzheimers disease. Its efficacy in severe dementia has not been assessed and is controversial. Our aim was to ascertain the effectiveness of donepezil in patients with severe Alzheimers disease, by focusing primarily on cognition and activities of daily living.nnnMETHODSnWe did a 6-month, double-blind, parallel-group, placebo-controlled study in 248 patients with severe Alzheimers disease (mini mental state examination score 1-10) who were living in assisted care nursing homes ran by trained staff in Sweden. We assigned patients oral donepezil (5 mg per day for 30 days then up to 10 mg per day thereafter, n=128) or matched placebo (n=120). Our primary endpoints were change from baseline to month 6 in the severe impairment battery (SIB) and modified Alzheimers Disease Cooperative Study activities of daily living inventory for severe Alzheimers disease (ADCS-ADL-severe). We analysed outcomes for patients with data at baseline and at one or more other timepoints (modified intent-to-treat population) with last observation carried forward used to replace missing data.nnnFINDINGSn95 patients assigned donepezil and 99 patients assigned placebo completed the study. Patients treated with donepezil improved more in SIB scores and declined less in ADCS-ADL-severe scores at 6 months after initiation of treatment compared with baseline than did controls (least squares [LS] mean difference, 5.7, 95% CI 1.5-9.8; p=0.008, and 1.7, 0.2-3.2; p=0.03, respectively). The incidence of adverse events was comparable between groups (donepezil 82% [n=105] vs placebo 76% [n=91]), with most being transient and mild or moderate in severity. More patients discontinued treatment because of adverse events in the donepezil group (n=20) than in the placebo group (n=8).nnnINTERPRETATIONnDonepezil improves cognition and preserves function in individuals with severe Alzheimers disease who live in nursing homes.

Effect of rivastigmine on delay to diagnosis of Alzheimer's disease from mild cognitive impairment: the InDDEx study

OBJECTIVEnTo assess the effect of rivastigmine in patients with mild cognitive impairment (MCI) on the time to clinical diagnosis of Alzheimers disease (AD) and the rate of cognitive decline.nnnMETHODSnThe study was a double-blind, randomised, placebo-controlled trial of up to 48 months. All patients had MCI operationally defined by having cognitive symptoms, a global clinical dementia rating stage of 0.5, a score of less than 9 on the New York University delayed paragraph recall test, and by not meeting the diagnostic criteria for AD. Primary efficacy variables were time to clinical diagnosis of AD, and change in performance on a cognitive test battery. This study is registered with the US National Institutes of Health clinical trials database (ClinicalTrials.gov), number NCT00000174.nnnFINDINGSnOf 1018 study patients enrolled, 508 were randomly assigned to rivastigmine and 510 to placebo; 17.3% of patients on rivastigmine and 21.4% on placebo progressed to AD (hazard ratio 0.85 [95% CI 0.64-1.12]; p=0.225). There was no significant difference between the rivastigmine and placebo groups on the standardised Z score for the cognitive test battery measured as mean change from baseline to endpoint (-0.10 [95% CI -0.63 to 0.44], p=0.726). Serious adverse events were reported by 141 (27.9%) rivastigmine-treated patients and 155 (30.5%) patients on placebo; adverse events of all types were reported by 483 (95.6%) rivastigmine-treated patients and 472 (92.7%) placebo-treated patients. The predominant adverse events were cholinergic: the frequencies of nausea, vomiting, diarrhoea, and dizziness were two to four times higher in the rivastigmine group than in the placebo group.nnnINTERPRETATIONnThere was no significant benefit of rivastigmine on the progression rate to AD or on cognitive function over 4 years. The overall rate of progression from MCI to AD in this randomised clinical trial was much lower than predicted. Rivastigmine treatment was not associated with any significant safety concerns.

Safety, tolerability, and antibody response of active Aβ immunotherapy with CAD106 in patients with Alzheimer's disease: randomised, double-blind, placebo-controlled, first-in-human study

BACKGROUNDnImmunotherapy targeting the amyloid β (Aβ) peptide is a potential strategy to slow the progression of Alzheimers disease. We aimed to assess the safety and tolerability of CAD106, a novel active Aβ immunotherapy for patients with Alzheimers disease, designed to induce N-terminal Aβ-specific antibodies without an Aβ-specific T-cell response.nnnMETHODSnWe did a phase 1, double-blind, placebo-controlled, 52-week study in two centres in Sweden. Participants, aged 50-80 years, with mild-to-moderate Alzheimers disease were entered into one of two cohorts according to time of study entry and then randomly allocated (by use of a computer-generated randomisation sequence) to receive either CAD106 or placebo (4:1; cohort one received CAD106 50 μg or placebo, cohort two received CAD106 150 μg or placebo). Each patient received three subcutaneous injections. All patients, caregivers, and investigators were masked to treatment allocation throughout the study. Primary objectives were to assess the safety and tolerability of CAD106 and to identify the Aβ-specific antibody response. Safety assessment was done by recording of all adverse events, assessment of MRI scans, physical and neurological examinations, vital signs, electrocardiography, electroencephalography, and laboratory analysis of blood and CSF. Patients with Aβ-IgG serum titres higher than 16 units at least once during the study were classified as responders. This study is registered with ClinicalTrials.gov, number NCT00411580.nnnFINDINGSnBetween August, 2005, and March, 2007, we randomly allocated 31 patients into cohort one (24 patients to CAD106 treatment and seven to placebo) and 27 patients into cohort two (22 patients to CAD106 treatment and five to placebo). 56 of 58 patients reported adverse events. In cohort one, nasopharyngitis was the most commonly reported adverse event (10 of 24 CAD106-treated patients). In cohort two, injection site erythema was the most commonly reported adverse event (14 of 22 CAD106-treated patients). Overall, nine patients reported serious adverse events--none was thought to be related to the study drug. We recorded no clinical or subclinical cases of meningoencephalitis. 16 of 24 (67%) CAD106-treated patients in cohort one and 18 of 22 (82%) in cohort two developed Aβ antibody response meeting pre-specified responder threshold. One of 12 placebo-treated patients (8%) had Aβ-IgG concentrations that qualified them as a responder.nnnINTERPRETATIONnOur findings suggest that CAD106 has a favourable safety profile and acceptable antibody response in patients with Alzheimers disease. Larger trials with additional dose investigations are needed to confirm the safety and establish the efficacy of CAD106.nnnFUNDINGnNovartis Pharma AG.

Influence of differential housing on emotional behaviour and neurotrophin levels in mice

Environmental enrichment condition (EC) induces profound behavioural, neurochemical and neuroanatomical changes. Increasing evidence has shown that the hippocampus, which is implicated in a range of cognitive functions, including learning and memory, is one of the most susceptible brain areas to the effects of enriched rearing. Recent work also suggests that the hippocampus is functionally segregated; lesion studies have shown that the dorsal hippocampus is important for spatial learning, whereas the ventral part is critical in emotional behaviour in rats. We investigated the effects of differential housing environments on anxiety-related behaviour and neurotrophin levels in dorsal and ventral hippocampus, and other brain regions. Ninety-six male and female C57BL/6 mice were reared in EC or standard housing condition (SC) for 4 months after weaning. Thereafter sixty-four animals were tested in the elevated plus-maze, open-field, novel-objects exploration and food neophobia. Thirty-two animals remained as untested. Subsequently, brain nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were analysed in selected brain regions of the tested and non-tested animals. Differential housing influenced anxiety-related behaviour in the plus-maze and brain neurotrophins. Baseline levels of BDNF and NGF protein were differently distributed in dorsal and ventral parts of hippocampus in both male and female mice, with levels in the dorsal hippocampal being consistently higher than those in ventral hippocampus. Exposure to behavioural testing induced complex changes on neurotrophin levels in selected brain regions. This study demonstrates for the first time the differential distribution of normal levels of neurotrophin protein in dorsal and ventral hippocampus in mice, and these levels can be affected by environmental enrichment and have an impact on emotional behaviour.

Neurogenic neuroepithelial and radial glial cells generated from six human embryonic stem cell lines in serum-free suspension and adherent cultures.

The great potential of human embryonic stem (hES) cells offers the opportunity both for studying basic developmental processes in vitro as well as for drug screening, modeling diseases, or future cell therapy. Defining protocols for the generation of human neural progenies represents a most important prerequisite. Here, we have used six hES cell lines to evaluate defined conditions for neural differentiation in suspension and adherent culture systems. Our protocol does not require fetal serum, feeder cells, or retinoic acid at any step, to induce neural fate decisions in hES cells. We monitored neurogenesis in differentiating cultures using morphological (including on‐line follow up), immunocytochemical, and RT‐PCR assays. For each hES cell line, in suspension or adherent culture, the same longitudinal progression of neural differentiation occurs. We showed the dynamic transitions from hES cells to neuroepithelial (NE) cells, to radial glial (RG) cells, and to neurons. Thus, 7 days after neural induction the majority of cells were NE, expressing nestin, Sox1, and Pax6. During neural proliferation and differentiation, NE cells transformed in RG cells, which acquired vimentin, BLBP, GLAST, and GFAP, proliferated and formed radial scaffolds. γ‐Aminobutyric acid (GABA)‐positive and glutamate positive neurons, few oligodendrocyte progenitors and astrocytes were formed in our conditions and timing. Our system successfully generates human RG cells and could be an effective source for neuronal replacement, since RG cells predominantly generate neurons and provide them with support and guidance.

Age and diagnostic performance of Alzheimer disease CSF biomarkers

Objectives: Core CSF changes in Alzheimer disease (AD) are decreased amyloid β1–42, increased total tau, and increased phospho-tau, probably indicating amyloid plaque accumulation, axonal degeneration, and tangle pathology, respectively. These biomarkers identify AD already at the predementia stage, but their diagnostic performance might be affected by age-dependent increase of AD-type brain pathology in cognitively unaffected elderly. Methods: We investigated effects of age on the diagnostic performance of CSF biomarkers in a uniquely large multicenter study population, including a cross-sectional cohort of 529 patients with AD dementia (median age 71, range 43–89 years) and 304 controls (67, 44–91 years), and a longitudinal cohort of 750 subjects without dementia with mild cognitive impairment (69, 43–89 years) followed for at least 2 years, or until dementia diagnosis. Results: The specificities for subjects without AD and the areas under the receiver operating characteristics curves decreased with age. However, the positive predictive value for a combination of biomarkers remained stable, while the negative predictive value decreased only slightly in old subjects, as an effect of the high AD prevalence in older ages. Conclusion: Although the diagnostic accuracies for AD decreased with age, the predictive values for a combination of biomarkers remained essentially stable. The findings highlight biomarker variability across ages, but support the use of CSF biomarkers for AD even in older populations.

Effect of phenserine treatment on brain functional activity and amyloid in Alzheimer's disease

The effects of (−)‐phenserine (phenserine) and placebo/donepezil treatment on regional cerebral metabolic rate for glucose (rCMRglc) and brain amyloid load were investigated by positron emission tomography in 20 patients with mild Alzheimers disease in relation to cerebrospinal fluid (CSF) and plasma biomarkers, and cognitive function.

The use of cholinesterase inhibitors and the risk of myocardial infarction and death: a nationwide cohort study in subjects with Alzheimer's disease

AIMSnCholinesterase inhibitors (ChEIs) are used for symptomatic treatment of Alzheimers disease. These drugs have vagotonic and anti-inflammatory properties that could be of interest also with respect to cardiovascular disease. This study evaluated the use of ChEIs and the later risk of myocardial infarction and death.nnnMETHODS AND RESULTSnThe cohort consisted of 7073 subjects (mean age 79 years) from the Swedish Dementia Registry with the diagnoses of Alzheimers dementia or Alzheimers mixed dementia since 2007. Cholinesterase inhibitor use was linked to diagnosed myocardial infarctions (MIs) and death using national registers. During a mean follow-up period of 503 (range 0-2009) days, 831 subjects in the cohort suffered MI or died. After adjustment for confounders, subjects who used ChEIs had a 34% lower risk for this composite endpoint during the follow-up than those who did not [hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.56-0.78]. Cholinesterase inhibitor use was also associated with a lower risk of death (HR: 0.64, 95% CI: 0.54-0.76) and MI (HR: 0.62, 95% CI: 0.40-0.95) when analysed separately. Subjects taking the highest recommended ChEI doses (donepezil 10 mg, rivastigmine >6 mg, galantamine 24 mg) had the lowest risk of MI (HR: 0.35, 95% CI: 0.19-0.64), or death (HR: 0.54, 95% CI: 0.43-0.67) compared with those who had never used ChEIs.nnnCONCLUSIONnCholinesterase inhibitor use was associated with a reduced risk of MI and death in a nationwide cohort of subjects diagnosed with Alzheimers dementia. These associations were stronger with increasing ChEI dose.

Safety and immunogenicity of the tau vaccine AADvac1 in patients with Alzheimer's disease: a randomised, double-blind, placebo-controlled, phase 1 trial

BACKGROUNDnNeurofibrillary pathology composed of tau protein is a main correlate of cognitive impairment in patients with Alzheimers disease. Immunotherapy targeting pathological tau proteins is therefore a promising strategy for disease-modifying treatment of Alzheimers disease. We have developed an active vaccine, AADvac1, against pathological tau proteins and assessed it in a phase 1 trial.nnnMETHODSnWe did a first-in-man, phase 1, 12 week, randomised, double-blind, placebo-controlled study of AADvac1 with a 12 week open-label extension in patients aged 50-85 years with mild-to-moderate Alzheimers disease at four centres in Austria. We randomly assigned patients with a computer-generated sequence in a 4:1 ratio overall to receive AADvac1 or placebo. They received three subcutaneous doses of AADvac1 or placebo from masked vaccine kits at monthly intervals, and then entered the open-label phase, in which all patients were allocated to AADvac1 treatment and received another three doses at monthly intervals. Patients, carers, and all involved with the trial were masked to treatment allocation. The primary endpoint was all-cause treatment-emergent adverse events, with separate analyses for injection site reactions and other adverse events. We include all patients who received at least one dose of AADvac1 in the safety assessment. Patients who had a positive IgG titre against the tau peptide component of AADvac1 at least once during the study were classified as responders. The first-in-man study is registered with EU Clinical Trials Register, number EudraCT 2012-003916-29, and ClinicalTrials.gov, number NCT01850238; the follow-up study, which is ongoing, is registered with EU Clinical Trials Register, number EudraCT 2013-004499-36, and ClinicalTrials.gov, number NCT02031198.nnnFINDINGSnThis study was done between June 9, 2013, and March 26, 2015. 30 patients were randomly assigned in the double-blind phase: 24 patients to the AADvac1 group and six to the placebo group. A total of 30 patients received AADvac1. Two patients withdrew because of serious adverse events. The most common adverse events were injection site reactions after administration (reported in 16 [53%] vaccinated patients [92 individual events]). No cases of meningoencephalitis or vasogenic oedema occurred after administration. One patient with pre-existing microhaemorrhages had newly occurring microhaemorrhages. Of 30 patients given AADvac1, 29 developed an IgG immune response. A geometric mean IgG antibody titre of 1:31415 was achieved. Baseline values of CD3+ CD4+ lymphocytes correlated with achieved antibody titres.nnnINTERPRETATIONnAADvac1 had a favourable safety profile and excellent immunogenicity in this first-in-man study. Further trials are needed to corroborate the safety assessment and to establish proof of clinical efficacy of AADvac1.nnnFUNDINGnAXON Neuroscience SE.

α-Melanocyte-stimulating hormone is neuroprotective in rat global cerebral ischemia

Abstract The aim of the study was to investigate the effects of alpha-melanocyte-stimulating hormone (α-MSH), a tridecapeptide derived from proopiomelanocortin (POMC), on the neurodegeneration following global cerebral ischemia and reperfusion in the rat. The biological activities of α-MSH include inhibition of inflammatory responses and anti-pyretic effects. Male Sprague-Dawley rats were subjected to four-vessel occlusion (4-VO) global cerebral ischemia followed by reperfusion, and treated with α-MSH (intraperitoneally, i.p.) at 30xa0min, and 24, 48, 72 and 96 h post-ischemia. Stereological quantification of the pyramidal cells in the CA1 area of the hippocampus showed that the number of viable neurons in ischemic rats was 96,945xa0±xa018,610 (meansxa0±xa0SD) as compared to 183,156xa0±xa049,935 in sham-operated rats (P