Cumulative, additive benefits of memantine-donepezil combination over component monotherapies in moderate to severe Alzheimer's dementia: a pooled area under the curve analysis.

INTRODUCTION: Treatment in moderate or severe Alzheimer's disease (AD) often involves adding memantine to a cholinesterase-inhibitor (ChEI: donepezil, galantamine, rivastigmine). Evidence from six-month randomized trials and long-term observational studies supports superiority of memantine-ChEI combination to ChEI monotherapy. We utilized area-under-the-curve (AUC) analysis to assess six-month cumulative treatment efficacy of memantine-donepezil combination versus component monotherapies on individual clinical domains and on a composite index. METHODS: Data were pooled from 1,408 individuals with moderate to severe AD from four six-month randomized trials of memantine monotherapy (n = 570) or add-on therapy (donepezil-only subset: n = 847). AUC changes from baseline on measures of cognition (SIB), function (ADCS-ADL19), behavior (NPI), global status (CIBIC-Plus), and a composite index (4D-CI: equally weighted composite of four domain measures) were calculated using the trapezoidal rule and evaluated via analysis of covariance (ANCOVA) (2-sided-α = 0.05). AUC results were contrasted with visit-by-visit changes from baseline ("snapshot analysis"), performed using a mixed-effects model with repeated measures (MMRM). RESULTS: Over the entire six-month period, placebo-only treatment was associated with significant cumulative worsening on all outcomes. Memantine-donepezil combination showed significantly greater AUC improvements (point x week) on the SIB, NPI, and CIBIC-Plus than placebo-donepezil (SIB: 68.4 versus 32.0, P = 0.019; NPI: -74.3 versus -28.2, P = 0.003; CIBIC-Plus: -2.5 versus 1.4, P = 0.006) and memantine-only monotherapies (SIB: 68.4 versus 12.0, P <0.001; NPI: -74.3 versus -7.4, P <0.001; CIBIC-Plus: -2.5 versus 2.7, P <0.001), whereas these comparisons were not significant for the ADCS-ADL19 (memantine-donepezil (1.4) versus placebo-donepezil (-0.9), P = 0.407; versus memantine-only (-12.2), P = 0.310). Composite index analysis demonstrated significant cumulative advantages of memantine-donepezil combination (630.0) over placebo-donepezil (344.7, P <0.001) and memantine-only (152.1, P <0.001) treatments. Combining memantine and donepezil had an additive effect. Compared with AUC analysis, baseline-to-endpoint change-score analysis underestimated effects of combination therapy, monotherapies, or both. CONCLUSIONS: This large pooled area-under-the-curve analysis of randomized-trial data in moderate to severe AD provides ecologically valid support that adding memantine to stable donepezil results in overall clinical benefits that are additive compared with individual monotherapies, continue to accumulate through six-month treatment, and are at least 50% greater than those of monotherapies.

The safety, tolerability, and efficacy of once-daily memantine (28 mg): a multinational, randomized, double-blind, placebo-controlled trial in patients with moderate-to-severe Alzheimer's disease taking cholinesterase inhibitors.

INTRODUCTION: Immediate-release memantine (10 mg, twice daily) is approved in the USA for moderate-to-severe Alzheimer's disease (AD). This study evaluated the efficacy, safety, and tolerability of a higher-dose, once-daily, extended-release formulation in patients with moderate-to-severe AD concurrently taking cholinesterase inhibitors. METHODS: In this 24-week, double-blind, multinational study (NCT00322153), outpatients with AD (Mini-Mental State Examination scores of 3-14) were randomized to receive once-daily, 28-mg, extended-release memantine or placebo. Co-primary efficacy parameters were the baseline-to-endpoint score change on the Severe Impairment Battery (SIB) and the endpoint score on the Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus). The secondary efficacy parameter was the baseline-to-endpoint score change on the 19-item Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL19); additional parameters included the baseline-to-endpoint score changes on the Neuropsychiatric Inventory (NPI) and verbal fluency test. Data were analyzed using a two-way analysis of covariance model, except for CIBIC-Plus (Cochran-Mantel-Haenszel test). Safety and tolerability were assessed through adverse events and physical and laboratory examinations. RESULTS: A total of 677 patients were randomized to receive extended-release memantine (n = 342) or placebo (n = 335); completion rates were 79.8 and 81.2 %, respectively. At endpoint (week 24, last observation carried forward), memantine-treated patients significantly outperformed placebo-treated patients on the SIB (least squares mean difference [95 % CI] 2.6 [1.0, 4.2]; p = 0.001), CIBIC-Plus (p = 0.008), NPI (p = 0.005), and verbal fluency test (p = 0.004); the effect did not achieve significance on ADCS-ADL19 (p = 0.177). Adverse events with a frequency of ≥5.0 % that were more prevalent in the memantine group were headache (5.6 vs. 5.1 %) and diarrhea (5.0 vs. 3.9 %). CONCLUSION: Extended-release memantine was efficacious, safe, and well tolerated in this population.

Efficacy and tolerability of nebivolol: does age matter? A retrospective analysis of three randomized, placebo-controlled trials in stage I-II hypertension.

OBJECTIVES: This retrospective analysis examined the efficacy and tolerability of nebivolol, a ß(1)-selective, vasodilatory ß-blocker, in four different age groups of patients with hypertension. METHODS: Data were pooled from three 12-week, randomized, placebo-controlled trials (placebo, n = 205; nebivolol [1.25-30/40 mg/day], n = 1811) and stratified into age quartiles (Group 1: 22-46 years; Group 2: 47-53 years; Group 3: 54-62 years; Group 4: 63-84 years). Only patients treated with placebo and the three commonly used nebivolol dosages (5, 10, and 20 mg/day) are presented. Baseline-to-endpoint changes in trough sitting diastolic blood pressure (DBP), systolic blood pressure (SBP), and heart rate (HR) were analyzed for each age quartile using an analysis of covariance (ANCOVA) model. Tolerability was assessed by means of adverse event (AE) rates. RESULTS: The analysis comprised 205 placebo-treated patients and 1380 patients treated with nebivolol dosages of 5, 10, or 20 mg/day. Older age was associated with higher SBP values at baseline. In all age groups, each of the three most frequently used nebivolol dosages significantly reduced DBP, compared with placebo (-9.1 to -11.8 mmHg versus -3.4 to -5.9 mmHg; p ≤ 0.008 overall). For SBP, a statistically significant effect versus placebo was observed for all dosages and age groups except for 5 and 10 mg/day in Group 4. Within each group, treatment with nebivolol (all three dosages) and placebo resulted in similar AE rates (nebivolol: 26.1-36.6%; placebo: 36.2-42.6%) and AE-related discontinuation rates (1.8-3.8% versus 0-4.3%). In each age group, there were no significant nebivolol-placebo differences in the rates of patients who experienced clinically significant changes or abnormal endpoint levels of metabolic parameters. CONCLUSIONS: This retrospective analysis suggests that nebivolol monotherapy is efficacious and well tolerated across various age groups, with the efficacy in reducing SBP somewhat diminishing in patients over 62 years of age.

Memantine and functional communication in Alzheimer's disease: results of a 12-week, international, randomized clinical trial.

Post hoc analyses suggest that memantine treatment may provide communication-related benefits in patients with Alzheimer's disease (AD). In this 12-week, international, randomized, double-blind, placebo-controlled trial of memantine (10 mg bid), the functional communication abilities of patients with AD (MMSE range: 10-19) were assessed using the Functional Linguistic Communication Inventory (FLCI; primary measure). Two combined subscales (Social Communication and Communication of Basic Needs) from the American Speech-Language-Hearing Association Functional Assessment of Communication Skills for Adults (ASHA FACS; secondary measure) were administered to caregivers. Treatment-emergent adverse events were also recorded. After 12 weeks, memantine-treated patients (n = 133) demonstrated a non-significant improvement on the FLCI (placebo: -0.6; memantine: 0.7; p = 0.070, LOCF) and a significant improvement on the ASHA FACS (placebo: -5.3; memantine: 0.5; p = 0.022), compared with placebo-treated patients (n = 124). Memantine had a low incidence of adverse events. In patients with moderate AD, memantine treatment improved functional communication, as recognized by caregivers.

Memantine discontinuation and the health status of nursing home residents with Alzheimer's disease.

OBJECTIVE: To estimate the effect of memantine discontinuation for a nonmedical reason (eg, formulary restriction or family decision) on the health status of nursing home (NH) residents with Alzheimer's disease (AD). DESIGN: Retrospective chart review. SETTING: NHs (n = 113) in the United States. PARTICIPANTS: Residents (minimum stay of 90 days) with AD, continuously treated with memantine (MC: n = 273) or discontinued for 60 days or longer (MD: n = 248). The subset of patients who discontinued for a nonmedical reason (MD-N: n = 163) was also analyzed, as was the subset of patients in groups MC and MD-N whose doses of concomitant medications remained stable (MC(s): n = 185; MD-N(s): n = 70). MEASUREMENTS: Thirty-one common geriatric and AD symptoms from NH charts were scored based on their emergence or resolution (+1 or -1 points, respectively), worsening or improvement (+0.5 or -0.5 points, respectively), or absence of change (0 points), compared with the baseline period (the first 30 days analyzed in the charts, during which all residents received memantine treatment). Patients' weight change was also captured. RESULTS: Compared with continuous treatment, memantine discontinuation was associated with a significant increase in the Total AD Symptom Change Score (ie, worsening) in all comparison pairs (MC versus MD, MC versus MD-N, and MC(s) versus MD-N(s): P < .001 for all). The symptoms showing greatest worsening aggregated into two factors: cognition and mood. CONCLUSION: Memantine discontinuation in NH residents with AD may be associated with declining health status, and should be considered with care. A randomized, placebo-controlled trial of treatment discontinuation is merited.

Memantine therapy of behavioral symptoms in community-dwelling patients with moderate to severe Alzheimer's disease.

Memantine is a moderate-affinity, uncompetitive antagonist of N-methyl-D-aspartate receptors, approved for the treatment of moderate to severe Alzheimer's disease (AD). Available data suggest that, in addition to its benefits on cognition, function, and global status, memantine treatment may also help alleviate behavioral symptoms. This article provides an overview of the prevalence, assessment, and treatment of behavioral disturbances in AD, and summarizes current knowledge regarding the effects of memantine on the behavior of community-dwelling patients. We searched EMBASE and PubMed (January 1992 to October 2008) for reports on memantine trials that involved outpatients with moderate to severe AD. All previously unpublished data were obtained from Forest Laboratories, Inc. Behavioral outcomes were assessed in three completed, double-blind, placebo-controlled trials.Overall, patients who received memantine performed better on behavioral measures than those treated with placebo. Post-hoc analyses suggest that memantine treatment was associated with a reduced severity or emergence of specific symptoms, particularly agitation and aggression. Prospective, well-designed trials are warranted to evaluate the efficacy of memantine in patients with significant behavioral symptoms.

Treatment options in Alzheimer's disease: maximizing benefit, managing expectations.

Alzheimer's disease (AD) is becoming an increasingly heavy burden on the society of developed countries, and physicians now face the challenge of providing efficient treatment regimens to an ever-higher number of individuals affected by the disease. Currently approved anti-AD therapies - the cholinesterase inhibitors and the N-methyl-D-aspartate receptor antagonist memantine - offer modest symptomatic relief, which can be enhanced using combination therapy with both classes of drugs. Additionally, alternative therapies such as nonsteroidal anti-inflammatory drugs, vitamin E, selegiline, Ginkgo biloba extracts, estrogens, and statins, as well as behavioral and lifestyle changes, have been explored as therapeutic options. Until a therapy is developed that can prevent or reverse the disease, the optimal goal for effective AD management is to develop a treatment regimen that will yield maximum benefits for individual patients across multiple domains, including cognition, daily functioning, and behavior, and to provide realistic expectations for patients and caregivers throughout the course of the disease. This review provides a basic overview of approved AD therapies, discusses some pharmacologic and nonpharmacologic treatment strategies that are currently being investigated, and offers suggestions for optimizing treatment to fit the needs of individual patients.

Increased apoptosis in cystinotic fibroblasts and renal proximal tubule epithelial cells results from cysteinylation of protein kinase Cdelta.

Cystinosis is a rare genetic disease characterized by defective lysosomal cystine transport and increased lysosomal cystine. How lysosomal cystine causes the lethal nephropathic phenotype is unknown. It was shown recently that cultured fibroblasts and renal proximal tubule epithelial cells whose lysosomes are cystine-loaded display a two-fold or greater increase in apoptosis after both intrinsic and extrinsic stimuli. The mechanism for the increased apoptosis is unknown. Protein kinase Cdelta (PKCdelta) is a proapoptotic protein kinase that has been shown in vitro to be activated via cysteinylation. This report now shows that PKCdelta forms disulfide bonds specifically with cystine that is released from lysosomes in cultured fibroblasts and renal proximal tubule epithelial cells during apoptosis. PKCdelta in cystinotic fibroblasts and renal proximal tubule epithelial cells have a four- to six-fold greater association with its substrate, lamin B, and a 2.5-fold increase in specific activity after TNF-alpha exposure. Both RNA inhibition and chemical inhibition of PKCdelta resulted in a significant decrease in apoptosis in cystinotic cells but not in normal cells. It is proposed that abnormally increased apoptosis plays a role in evolution of the cystinotic phenotype.

Integrative proteomics: functional and molecular characterization of a particular glutamate-related neuregulin isoform.

Glutamate is the major excitatory neurotransmitter in the mammalian brain and is related to memory by calcium-conducting receptors. Neuregulins have emerged as long-term modulating molecules of synaptic signaling by glutamate receptors, playing a role in some cognition/memory-related disorders and moreover being part of transient functional microdomains, called lipid rafts. Here we characterize one specific isoform of neuregulin as a central biomarker for glutamate-related signaling, integrating results from in vitro and in vivo models by a differential functional and proteomic approach.

Modulation of feeding-related peptide/protein signals by the blood-brain barrier.

The peptide urocortin is a member of the corticotropin-releasing factor (CRF) family and a potent satiety signal to the brain. Urocortin in blood does not reach the brain significantly by itself, but its permeation across the blood-brain barrier (BBB) can be enhanced by leptin. How leptin facilitates the influx of urocortin has not been elucidated. In this study, we tested the hypothesis that leptin activates receptor-mediated endocytosis of urocortin. We measured the kinetics of permeation of radioactively labeled urocortin across the mouse BBB and determined the specific effects of leptin and receptor antibodies. The results show that the influx transfer constant of urocortin was enhanced in the presence of leptin and mediated by CRF-2beta, the specific receptor for urocortin. To determine the specificity of this modulation, the effect of leptin was compared with that of TNFalpha. Both TNFalpha and leptin independently facilitated receptor-mediated transport of urocortin across the BBB. Even though TNFalpha and leptin have similar effects on urocortin transport, leptin did not significantly affect the influx of TNFalpha across the BBB. The results indicate that permeation of ingestive peptides and cytokines across the BBB can be acutely modulated, consistent with a role of BBB in regulating feeding behavior. Thus, sites of action of leptin, urocortin, and TNFalpha exist not only in the brain but also at the BBB where they each control the flow of other ingestive signals to CNS targets.

Brain proteome of mice lacking the receptors for tumor necrosis factor alpha.

Tumor necrosis factor alpha (TNF alpha) is involved in regulation of food intake, inflammatory response, and cancer cachexia. Its actions are mediated by at least two receptors: TNFR1 and TNFR2. We show that mice lacking the TNF alpha receptors have altered levels of proteins that take part in signal transduction, stress response, protein folding, glucose and amino acid metabolism, vesicle trafficking, and cytoskeletal arrangements. This is the first time that some of them have been associated with TNF alpha signaling pathways.