Summary Background Leuco-methylthioninium bis(hydromethanesulfonate; LMTM), a stable reduced form of the methylthioninium moiety, acts as a selective inhibitor of tau protein aggregation both in vitro and in transgenic mouse models. Methylthioninium chloride has previously shown potential efficacy as monotherapy in patients with Alzheimer’s disease. We aimed to determine whether LMTM was safe and effective in modifying disease progression in patients with mild to moderate Alzheimer’s disease. Methods We did a 15-month, randomised, controlled double-blind, parallel-group trial at 115 academic centres and private research clinics in 16 countries in Europe, North America, Asia, and Russia with patients younger than 90 years with mild to moderate Alzheimer’s disease. Patients concomitantly using other medicines for Alzheimer’s disease were permitted to be included because we considered it infeasible not to allow their inclusion; however, patients using medicines carrying warnings of methaemoglobinaemia were excluded because the oxidised form of methylthioninium in high doses has been shown to induce this condition. We randomly assigned participants (3:3:4) to 75 mg LMTM twice a day, 125 mg LMTM twice a day, or control (4 mg LMTM twice a day to maintain blinding with respect to urine or faecal discolouration) administered as oral tablets. We did the randomisation with an interactive web response system using 600 blocks of length ten, and stratified patients by severity of disease, global region, whether they were concomitantly using Alzheimer’s disease-labelled medications, and site PET capability. Participants, their study partners (generally carers), and all assessors were masked to treatment assignment throughout the study. The coprimary outcomes were progression on the Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog) and the Alzheimer’s Disease Co-operative Study–Activities of Daily Living Inventory (ADCS-ADL) scales from baseline assessed at week 65 in the modified intention-to-treat population. This trial is registered with Clinicaltrials.gov (NCT01689246) and the European Union Clinical Trials Registry (2012-002866-11). Findings Between Jan 29, 2013, and June 26, 2014, we recruited and randomly assigned 891 participants to treatment (357 to control, 268 to 75 mg LMTM twice a day, and 266 to 125 mg LMTM twice a day). The prespecified primary analyses did not show any treatment benefit at either of the doses tested for the coprimary outcomes (change in ADAS-Cog score compared with control [n=354, 6·32, 95% CI 5·31–7·34]: 75 mg LMTM twice a day [n=257] –0·02, –1·60 to 1·56, p=0·9834, 125 mg LMTM twice a day [n=250] –0·43, –2·06 to 1·20, p=0·9323; change in ADCS-ADL score compared with control [–8·22, 95% CI –9·63 to –6·82]: 75 mg LMTM twice a day –0·93, –3·12 to 1·26, p=0·8659; 125 mg LMTM twice a day –0·34, –2·61 to 1·93, p=0·9479). Gastrointestinal and urinary effects were the most common adverse events with both high doses of LMTM, and the most common causes for discontinuation. Non-clin...
disease (AD) is important for clinical management and affords the opportunity to assess potential disease-modifying agents in clinical trials. To our knowledge, this is the first report of a randomized trial to prospectively enrich a study population with prodromal AD (PDAD) defined by cerebrospinal fluid (CSF) biomarker criteria and mild cognitive impairment (MCI) symptoms. OBJECTIVES To assess the safety of the γ-secretase inhibitor avagacestat in PDAD and to determine whether CSF biomarkers can identify this patient population prior to clinical diagnosis of dementia. DESIGN, SETTING, AND PARTICIPANTS A randomized, placebo-controlled phase 2 clinical trial with a parallel, untreated, nonrandomized observational cohort of CSF biomarker-negative participants was conducted May 26, 2009, to July 9, 2013, in a multicenter global population. Of 1358 outpatients screened, 263 met MCI and CSF biomarker criteria for randomization into the treatment phase. One hundred two observational cohort participants who met MCI criteria but were CSF biomarker-negative were observed during the same study period to evaluate biomarker assay sensitivity. INTERVENTIONS Oral avagacestat or placebo daily. MAIN OUTCOMES AND MEASURE Safety and tolerability of avagacestat. RESULTS Of the 263 participants in the treatment phase, 132 were randomized to avagacestat and 131 to placebo; an additional 102 participants were observed in an untreated observational cohort. Avagacestat was relatively well tolerated with low discontinuation rates (19.6%) at a dose of 50 mg/d, whereas the dose of 125 mg/d had higher discontinuation rates (43%), primarily attributable to gastrointestinal tract adverse events. Increases in nonmelanoma skin cancer and nonprogressive, reversible renal tubule effects were observed with avagacestat. Serious adverse event rates were higher with avagacestat (49 participants [37.1%]) vs placebo (31 [23.7%]), attributable to the higher incidence of nonmelanoma skin cancer. At 2 years, progression to dementia was more frequent in the PDAD cohort (30.7%) vs the observational cohort (6.5%). Brain atrophy rate in PDAD participants was approximately double that of the observational cohort. Concordance between abnormal amyloid burden on positron emission tomography and pathologic CSF was approximately 87% (κ = 0.68; 95% CI, 0.48-0.87). No significant treatment differences were observed in the avagacestat vs placebo arm in key clinical outcome measures. CONCLUSIONS AND RELEVANCE Avagacestat did not demonstrate efficacy and was associated with adverse dose-limiting effects. This PDAD population receiving avagacestat or placebo had higher rates of clinical progression to dementia and greater brain atrophy compared with CSF biomarker-negative participants. The CSF biomarkers and amyloid positron emission tomography imaging were correlated, suggesting that either modality could be used to confirm the presence of cerebral amyloidopathy and identify PDAD. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00890890
Background:LMTM is being developed as a treatment for AD based on inhibition of tau aggregation.Objectives:To examine the efficacy of LMTM as monotherapy in non-randomized cohort analyses as modified primary outcomes in an 18-month Phase III trial in mild AD.Methods:Mild AD patients (n = 800) were randomly assigned to 100 mg twice a day or 4 mg twice a day. Prior to unblinding, the Statistical Analysis Plan was revised to compare the 100 mg twice a day as monotherapy subgroup (n = 79) versus 4 mg twice a day as randomized (n = 396), and 4 mg twice a day as monotherapy (n = 76) versus 4 mg twice a day as add-on therapy (n = 297), with strong control of family-wise type I error.Results:The revised analyses were statistically significant at the required threshold of p < 0.025 in both comparisons for change in ADAS-cog, ADCS-ADL, MRI atrophy, and glucose uptake. The brain atrophy rate was initially typical of mild AD in both add-on and monotherapy groups, but after 9 months of treatment, the rate in monotherapy patients declined significantly to that reported for normal elderly controls. Differences in severity or diagnosis at baseline between monotherapy and add-on patients did not account for significant differences in favor of monotherapy.Conclusions:The results are consistent with earlier studies in supporting the hypothesis that LMTM might be effective as monotherapy and that 4 mg twice a day may serve as well as higher doses. A further suitably randomized trial is required to test this hypothesis.
G ranulocyte colony-stimulating factor (G-CSF) is a growth factor already in clinical use for the treatment of chemotherapy-associated neutropenia. 1 During the past 9 years, a vast body of evidence has demonstrated that G-CSF is a potent neuronal growth factor with multimodal antiapoptotic, arteriogenic, and neurogenic properties. 2-4Background and Purpose-Granulocyte colony-stimulating factor (G-CSF; AX200; Filgrastim) is a stroke drug candidate with excellent preclinical evidence for efficacy. A previous phase IIa dose-escalation study suggested potential efficacy in humans. The present large phase IIb trial was powered to detect clinical efficacy in acute ischemic stroke patients. Methods-G-CSF (135 µg/kg body weight intravenous over 72 hours) was tested against placebo in 328 patients in a multinational, multicenter, randomized, and placebo-controlled trial (NCT00927836; www.clinicaltrial.gov). Main inclusion criteria were ≤9-hour time window after stroke onset, infarct localization in the middle cerebral artery territory, baseline National Institutes of Health Stroke Scale score range of 6 to 22, and baseline diffusion-weighted imaging lesion size ≥15 mL. Primary and secondary end points were the modified Rankin scale score and the National Institutes of Health Stroke Scale score at day 90, respectively. Data were analyzed using a prespecified model that adjusted for age, National Institutes of Health Stroke Scale score at baseline, and initial infarct volume (diffusion-weighted imaging). Results-G-CSF treatment failed to meet the primary and secondary end points of the trial. For additional end points such as mortality, Barthel index, or infarct size at day 30, G-CSF did not show efficacy either. There was, however, a trend for reduced infarct growth in the G-CSF group. G-CSF showed the expected peripheral pharmacokinetic and pharmacodynamic profiles, with a strong increase in leukocytes and monocytes. In parallel, the cytokine profile showed a significant decrease of interleukin-1. The large amount of animal data from different laboratories and their meta-analyses indicated G-CSF as one of the most promising drug candidates for stroke treatment. [5][6][7] In particular, G-CSF had been shown to improve long-term functional recovery after stroke even if treatment was delayed for days. Conclusions-G-CSF,8 A phase IIa clinical trial in 43 acute ischemic stroke patients demonstrated feasibility and safety of intravenous G-CSF therapy in acute stroke 9 and allowed identification of an optimal dose of 135 µg/kg body weight over 72 hours for this trial. The aim of the AX200 for Ischemic Stroke (AXIS) 2 trial was to show clinical efficacy of this dose for the treatment of acute ischemic stroke. Materials and Methods Study Type and RandomizationAXIS 2 was a European, multicenter, placebo-controlled, randomized, and double-blind trial. The study was performed according to the International Conference of Harmonization Good Clinical Practice and was approved by the respective regulatory authorities (first approva...
Background and Purpose-Cerebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage and cognitive impairment and is associated with white matter hyperintensities and cerebral microbleeds. MRI diffusion tensor imaging detects microstructural tissue damage in advanced CAA even in areas that appear normal on conventional MRI. We hypothesized that higher global mean apparent diffusion coefficient (mean ADC), reflecting a higher amount of chronic tissue disruption caused by CAA, would be independently associated with CAA-related cognitive impairment. Methods-Preintracerebral hemorrhage cognitive impairment was systematically assessed using a standardized questionnaire (IQCODE) in 49 patients. Volume of white matter hyperintensities, number of microbleeds, and mean ADC were determined from MRIs obtained within 14.0Ϯ22.5 days of intracerebral hemorrhage cognitive impairment. White matter hyperintensities and mean ADC were measured in the hemisphere uninvolved by intracerebral hemorrhage to avoid confounding. Results-Preintracerebral hemorrhage cognitive impairment was identified in 10 of 49 subjects. Mean ADC was the only variable associated with preintracerebral hemorrhage cognitive impairment and was elevated in those with preintracerebral hemorrhage cognitive impairment compared with those without (12.4ϫ10 Ϫ4 versus 11.7ϫ10 Ϫ4 mm 2 /s; Pϭ0.03). Mean ADC positively correlated with age but not white matter hyperintensities or number of microbleeds. In logistic regression controlling for age and visible cerebral atrophy, mean ADC was independently associated with preintracerebral hemorrhage cognitive impairment (OR per 1ϫ10 Ϫ4 mm 2 /s increaseϭ2.45, 95% CI 1.11 to 5.40, Pϭ0.04). Conclusions-Mean ADC is independently associated with preintracerebral hemorrhage cognitive impairment in CAA.The lack of correlation with other MRI markers of CAA suggests that mean ADC may be sensitive to distinct aspects of CAA pathology and its tissue consequences. These results suggest that global MRI diffusion changes are sensitive to clinically relevant microstructural alterations and may be useful markers of CAA-related tissue damage. Key Words: cerebral amyloid angiopathy Ⅲ cerebral microhemorrhage Ⅲ cognitive impairment Ⅲ dementia Ⅲ diffusion Ⅲ microbleeds Ⅲ white matter disease C erebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage (ICH) and cognitive impairment in the elderly and is associated with a high prevalence of markers of small vessel disease, including white matter hyperintensities (WMH) and cerebral microbleeds (MB). [1][2][3][4] ICH in sporadic CAA is likely caused by vessel fragility and rupture due to the deposition of amyloid within the media and adventitia of small-to medium-sized cerebral arteries. 5 The presence of WMH visualized on conventional MRI sequences 4 suggests that vascular amyloid deposition may alter white matter perfusion by causing stenosis or vascular dysfunction. 6 This hypothesis is supported by the observations of extensive white matter damage ...
Background and Purpose-White matter hyperintensities (WMH) on MRI are a quantitative marker for sporadic cerebral small vessel disease and are highly heritable. To date, large-scale genetic studies have identified only a single locus influencing WMH burden. This might in part relate to biological heterogeneity of sporadic WMH. The current study searched for genetic modifiers of WMH volume in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a monogenic small vessel disease. Methods-We performed a genome-wide association study to identify quantitative trait loci for WMH volume by combining data from 517 CADASIL patients collected through 7 centers across Europe. WMH volumes were centrally analyzed and quantified on fluid attenuated inversion recovery images. Genotyping was performed using the Affymetrix 6.0 platform. Individuals were assigned to 2 distinct genetic clusters (cluster 1 and cluster 2) based on their genetic background. Results-Four hundred sixty-six patients entered the final genome-wide association study analysis. The phenotypic variance of WMH burden in CADASIL explained by all single nucleotide polymorphisms in cluster 1 was 0.85 (SE=0.21), suggesting a substantial genetic contribution. Using cluster 1 as derivation and cluster 2 as a validation sample, a polygenic score was significantly associated with WMH burden (P=0.001) after correction for age, sex, and vascular risk factors. No single nucleotide polymorphism reached genome-wide significance. Conclusions-We found a polygenic score to be associated with WMH volume in CADASIL subjects. Our findings suggest that multiple variants with small effects influence WMH burden in CADASIL. The identification of these variants and the biological pathways involved will provide insights into the pathophysiology of white matter disease in CADASIL and possibly small vessel disease in general. (Stroke. 2014;45:968-972.)
Background: Although hydromethylthionine is a potent tau aggregation inhibitor, no difference was found in either of two Phase III trials in mild to moderate Alzheimer's disease (AD) comparing doses in the range 150-250 mg/day with 8 mg/day intended as a control. Objective: To determine how drug exposure is related to treatment response. Methods: A sensitive plasma assay for the drug was used in a population pharmacokinetic analysis of samples from 1,162 of the 1,686 patients who participated in either of the Phase III trials with available samples and efficacy outcome data. Results: There are steep concentration-response relationships for steady state plasma levels in the range 0.3-0.8 ng/ml at the 8 mg/day dose. Using a threshold based on the lower limit of quantitation of the assay on Day 1, there are highly significant differences in cognitive decline and brain atrophy in patients with above threshold plasma levels, both for monotherapy and add-on therapy, but with effect sizes reduced by half as add-on. Plasma concentrations in the range 4-21 ng/ml produced by the high doses are not associated with any additional benefit.
Introduction Solanezumab is a humanized monoclonal antibody that preferentially binds to soluble amyloid β and promotes its clearance from the brain in preclinical studies. The objective of this study was to assess the effect of solanezumab in slowing global and anatomically localized brain atrophy as measured by volumetric magnetic resonance imaging (MRI). Methods In the EXPEDITION3 phase 3 trial, participants with mild Alzheimer's disease were randomized to receive intravenous infusions of either 400 mg of solanezumab or placebo every 4 weeks for 76 weeks. Volumetric MRI scans were acquired at baseline and at 80 weeks from 275 MRI facilities using a standardized imaging protocol. A subset of 1462 patients who completed both MRI and 14-item Alzheimer's Disease Assessment Scale–Cognitive Subscale assessments at both time points were selected for analysis. Longitudinal MRI volume changes were analyzed centrally by tensor-based morphometry with a standard FreeSurfer brain parcellation. Prespecified volumetric measures, including whole brain and ventricles, along with anatomically localized regions in the temporal, parietal, and frontal lobes were evaluated in those participants. Results Group-mean differences in brain atrophy rates were directionally consistent across a number of brain regions but small in magnitude (1.3–6.9% slowing) and not statistically significant when corrected for multiple comparisons. The annualized rates of change of the volumetric measures and the correlation of these changes with cognitive changes in placebo-treated subjects were similar to those reported previously. Discussion In the EXPEDITION3 trial, solanezumab did not significantly slow down rates of global or anatomically localized brain atrophy. Brain volume changes and their relationship to cognition were consistent with previous reports.
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