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- Gobom, Johan, et al.
(författare)
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Validation of the LUMIPULSE automated immunoassay for the measurement of core AD biomarkers in cerebrospinal fluid.
- 2022
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Ingår i: Clinical chemistry and laboratory medicine. - : Walter de Gruyter GmbH. - 1437-4331 .- 1434-6621. ; 60:2, s. 207-219
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Tidskriftsartikel (refereegranskat)abstract
- The core cerebrospinal fluid (CSF) biomarkers; total tau (tTau), phospho-tau (pTau), amyloid β1-42(Aβ 1-42), and the Aβ 1-42/Aβ 1-40 ratio have transformed Alzheimer's disease (AD) research and are today increasingly used in clinical routine laboratories as diagnostic tools. Fully automated immunoassay instruments with ready-to-use assay kits and calibrators has simplified their analysis and improved reproducibility of measurements. We evaluated the analytical performance of the fully automated immunoassay instrument LUMIPULSE G (Fujirebio) for measurement of the four core AD CSF biomarkers and determined cutpoints for AD diagnosis.Comparison of the LUMIPULSE G assays was performed with the established INNOTEST ELISAs (Fujirebio) for hTau Ag, pTau 181, β-amyloid 1-42, and with V-PLEX Plus Aβ Peptide Panel 1 (6E10) (Meso Scale Discovery) for Aβ 1-42/Aβ 1-40, as well as with a LC-MS reference method for Aβ 1-42. Intra- and inter-laboratory reproducibility was evaluated for all assays. Clinical cutpoints for Aβ 1-42, tTau, and pTau was determined by analysis of three cohorts of clinically diagnosed patients, comprising 651 CSF samples. For the Aβ 1-42/Aβ 1-40 ratio, the cutpoint was determined by mixture model analysis of 2,782 CSF samples.The LUMIPULSE G assays showed strong correlation to all other immunoassays (r>0.93 for all assays). The repeatability (intra-laboratory) CVs ranged between 2.0 and 5.6%, with the highest variation observed for β-amyloid 1-40. The reproducibility (inter-laboratory) CVs ranged between 2.1 and 6.5%, with the highest variation observed for β-amyloid 1-42. The clinical cutpoints for AD were determined to be 409ng/L for total tau, 50.2ng/L for pTau 181, 526ng/L for β-amyloid 1-42, and 0.072 for the Aβ 1-42/Aβ 1-40 ratio.Our results suggest that the LUMIPULSE G assays for the CSF AD biomarkers are fit for purpose in clinical laboratory practice. Further, they corroborate earlier presented reference limits for the biomarkers.
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| 2. |
- Hey, John A., et al.
(författare)
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Effects of Oral ALZ-801/Valiltramiprosate on Plasma Biomarkers, Brain Hippocampal Volume, and Cognition: Results of 2-Year Single-Arm, Open-Label, Phase 2 Trial in APOE4 Carriers with Early Alzheimer's Disease
- 2024
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Ingår i: DRUGS. - 0012-6667 .- 1179-1950. ; 84, s. 811-823
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Tidskriftsartikel (refereegranskat)abstract
- Introduction ALZ-801/valiltramiprosate is a small-molecule oral inhibitor of beta amyloid (A beta) aggregation and oligomer formation being studied in a phase 2 trial in APOE4 carriers with early Alzheimer's disease (AD) to evaluate treatment effects on fluid and imaging biomarkers and cognitive assessments.Methods The single-arm, open-label phase 2 trial was designed to evaluate the effects of the ALZ-801 265 mg tablet taken twice daily (after 2 weeks once daily) on plasma fluid AD biomarkers, hippocampal volume (HV), and cognition over 104 weeks in APOE4 carriers. The study enrolled subjects aged 50-80 years, with early AD [Mini-Mental State Examination (MMSE) >= 22, Clinical Dementia Rating-Global (CDR-G) 0.5 or 1], apolipoprotein E4 (APOE4) genotypes including APOE4/4 and APOE3/4 genotypes, and positive cerebrospinal fluid (CSF) AD biomarkers or prior amyloid scans. The primary outcome was plasma p-tau181, HV evaluated by magnetic resonance imaging (MRI) was the key secondary outcome, and plasma A beta 42 and A beta 40 were the secondary biomarker outcomes. The cognitive outcomes were the Rey Auditory Verbal Learning Test and the Digit Symbol Substitution Test. Safety and tolerability evaluations included treatment-emergent adverse events and amyloid-related imaging abnormalities (ARIA). The study was designed and powered to detect 15% reduction from baseline in plasma p-tau181 at the 104-week endpoint. A sample size of 80 subjects provided adequate power to detect this difference at a significance level of 0.05 using a two-sided paired t-test.Results The enrolled population of 84 subjects (31 homozygotes and 53 heterozygotes) was 52% females, mean age 69 years, MMSE 25.7 [70% mild cognitive impairment (MCI), 30% mild AD] with 55% on cholinesterase inhibitors. Plasma p-tau181 reduction from baseline was significant (31%, p = 0.045) at 104 weeks and all prior visits; HV atrophy was significantly reduced (p = 0.0014) compared with matched external controls from an observational Early AD study. Memory scores showed minimal decline from baseline over 104 weeks and correlated significantly with decreased HV atrophy (Spearman's 0.44, p = 0.002). Common adverse events were COVID infection and mild nausea, and no drug-related serious adverse events were reported. Of 14 early terminations, 6 were due to nonserious treatment-emergent adverse events and 1 death due to COVID. There was no vasogenic brain edema observed on MRI over 104 weeks.Conclusions The effect of ALZ-801 on reducing plasma p-tau181 over 2 years demonstrates target engagement and supports its anti-A beta oligomer action that leads to a robust decrease in amyloid-induced brain neurodegeneration. The significant correlation between reduced HV atrophy and cognitive stability over 2 years suggests a disease-modifying effect of ALZ-801 treatment in patients with early AD. Together with the favorable safety profile with no events of vasogenic brain edema, these results support further evaluation of ALZ-801 in a broader population of APOE4 carriers, who represent two-thirds of patients with AD.Trial Registration https://clinicaltrials.gov/study/NCT04693520.
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