151
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Lu Y, Riddell D, Hajos-Korcsok E, Bales K, Wood KM, Nolan CE, Robshaw AE, Zhang L, Leung L, Becker SL, Tseng E, Barricklow J, Miller EH, Osgood S, O'Neill BT, Brodney MA, Johnson DS, Pettersson M. Cerebrospinal fluid amyloid-β (Aβ) as an effect biomarker for brain Aβ lowering verified by quantitative preclinical analyses. J Pharmacol Exp Ther 2012; 342:366-75. [PMID: 22562771 PMCID: PMC11047765 DOI: 10.1124/jpet.112.192625] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/27/2012] [Indexed: 01/01/2023] Open
Abstract
Reducing the generation of amyloid-β (Aβ) in the brain via inhibition of β-secretase or inhibition/modulation of γ-secretase has been pursued as a potential disease-modifying treatment for Alzheimer's disease. For the discovery and development of β-secretase inhibitors (BACEi), γ-secretase inhibitors (GSI), and γ-secretase modulators (GSM), Aβ in cerebrospinal fluid (CSF) has been presumed to be an effect biomarker for Aβ lowering in the brain. However, this presumption is challenged by the lack of quantitative understanding of the relationship between brain and CSF Aβ lowering. In this study, we strived to elucidate how the intrinsic pharmacokinetic (PK)/pharmacodynamic (PD) relationship for CSF Aβ lowering is related to that for brain Aβ through quantitative modeling of preclinical data for numerous BACEi, GSI, and GSM across multiple species. Our results indicate that the intrinsic PK/PD relationship in CSF is predictive of that in brain, at least in the postulated pharmacologically relevant range, with excellent consistency across mechanisms and species. As such, the validity of CSF Aβ as an effect biomarker for brain Aβ lowering is confirmed preclinically. Meanwhile, we have been able to reproduce the dose-dependent separation between brain and CSF effect profiles using simulations. We further discuss the implications of our findings to drug discovery and development with regard to preclinical PK/PD characterization and clinical prediction of Aβ lowering in the brain.
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Affiliation(s)
- Yasong Lu
- MS#220-4546, Department of Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Eastern Point Road, Groton, CT 06340, USA.
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152
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Abstract
Dementia due to Alzheimer's disease (AD) is estimated to reach epidemic proportions by the year 2030. Given the limited accuracy of current AD clinical diagnosis, biomarkers of AD pathologies are currently being sought. Reductions in cerebrospinal fluid levels of β-amyloid 42 (a marker of amyloid plaques) and elevations in tau species (markers of neurofibrillary tangles and/or neurodegeneration) are well-established as biomarkers useful for AD diagnosis and prognosis. However, novel markers for other features of AD pathophysiology (e.g., β-amyloid processing, neuroinflammation and neuronal stress/dysfunction) and for other non-AD dementias are required to improve the accuracy of AD disease diagnosis, prognosis, staging and therapeutic monitoring (theragnosis). This article discusses the potential of several promising novel cerebrospinal fluid analytes, highlights the next steps critical for advancement in the field, and provides a prediction on how the field may evolve in 5-10 years.
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Affiliation(s)
- Anne M Fagan
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Ave., St Louis, MO 63110, USA.
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153
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Sperling RA, Jack CR, Aisen PS. Testing the right target and right drug at the right stage. Sci Transl Med 2012; 3:111cm33. [PMID: 22133718 DOI: 10.1126/scitranslmed.3002609] [Citation(s) in RCA: 392] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Alzheimer's disease (AD) is the only leading cause of death for which no disease-modifying therapy is currently available. Recent disappointing trial results at the dementia stage of AD have raised multiple questions about our current approaches to the development of disease-modifying agents. Converging evidence suggests that the pathophysiological process of AD begins many years before the onset of dementia. So why do we keep testing drugs aimed at the initial stages of the disease process in patients at the end-stage of the illness?
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Affiliation(s)
- Reisa A Sperling
- Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02446, USA.
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154
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Rosenberg GA. Neurological diseases in relation to the blood-brain barrier. J Cereb Blood Flow Metab 2012; 32:1139-51. [PMID: 22252235 PMCID: PMC3390801 DOI: 10.1038/jcbfm.2011.197] [Citation(s) in RCA: 306] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/01/2011] [Accepted: 12/02/2011] [Indexed: 11/09/2022]
Abstract
Disruption of the blood-brain barrier (BBB) has an important part in cellular damage in neurological diseases, including acute and chronic cerebral ischemia, brain trauma, multiple sclerosis, brain tumors, and brain infections. The neurovascular unit (NVU) forms the interface between the blood and brain tissues. During an injury, the cascade of molecular events ends in the final common pathway for BBB disruption by free radicals and proteases, which attack membranes and degrade the tight junction proteins in endothelial cells. Free radicals of oxygen and nitrogen and the proteases, matrix metalloproteinases and cyclooxgyenases, are important in the early and delayed BBB disruption as the neuroinflammatory response progresses. Opening of the BBB occurs in neurodegenerative diseases and contributes to the cognitive changes. In addition to the importance of the NVU in acute injury, angiogenesis contributes to the recovery process. The challenges to treatment of the brain diseases involve not only facilitating drug entry into the brain, but also understanding the timing of the molecular cascades to block the early NVU injury without interfering with recovery. This review will describe the molecular and cellular events associated with NVU disruption and potential strategies directed toward restoring its integrity.
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Affiliation(s)
- Gary A Rosenberg
- Departments of Neurology, Neurosciences, Cell Biology and Physiology and Mathematics and Statistics, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
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155
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Panza F, Frisardi V, Imbimbo BP, Logroscino G, Seripa D, Pilotto A, Solfrizzi V. Amyloid-related imaging abnormalities associated with immunotherapy in Alzheimer’s disease patients. FUTURE NEUROLOGY 2012. [DOI: 10.2217/fnl.12.42] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Evaluation of: Sperling R, Salloway S, Brooks DJ et al. Amyloid-related imaging abnormalities in patients with Alzheimer’s disease treated with bapineuzumab: a retrospective analysis. Lancet Neurol. 11(3), 241–249 (2012). Amyloid-related imaging abnormalities (ARIAs) have been reported in patients with Alzheimer’s disease treated with bapineuzumab, a monoclonal antibody targeting β-amyloid (Aβ). The spectrum of ARIA includes signal hyperintensities on fluid attenuation inversion recovery sequences thought to represent ‘vasogenic edema’ and/or sulcal effusion (ARIA-E), as well as signal hypointensities on gradient echo/T2* thought to represent hemosiderin deposits. This study was a retrospective analysis in which two neuroradiologists independently reviewed 2572 fluid attenuation inversion recovery MRI scans from 262 participants in two Phase II studies of bapineuzumab and an open-label extension study. In this analysis, several ARIA-E cases were identified that were initially missed in the reported studies of bapineuzumab (42%). Associated clinical symptoms were observed in only 22% of patients with ARIA-E. Occurrence of ARIA-E increased with bapineuzumab dose and presence of apolipoprotein E (APOE) ε4 alleles. The increased risk of ARIA-E in APOE ε4 carriers and the knowledge that vasogenic edema and microhemorrhages may spontaneously occur in cerebral amyloid angiopathy suggest a potential relationship with vascular Aβ burden. The increased risk of ARIA with a high bapineuzumab dose and the findings from a case with PET amyloid imaging also suggest a possible relationship between ARIA-E with Aβ clearance after passive immunotherapy with monoclonal antibodies.
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Affiliation(s)
- Francesco Panza
- Geriatric Unit & Gerontology-Geriatric Research Laboratory, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013, San Giovanni Rotondo, Foggia, Italy
| | - Vincenza Frisardi
- Geriatric Unit & Gerontology-Geriatric Research Laboratory, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013, San Giovanni Rotondo, Foggia, Italy
- Department of Neurological & Psychiatric Sciences, University of Bari, Bari, Italy
| | - Bruno P Imbimbo
- Research & Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Giancarlo Logroscino
- Department of Neurological & Psychiatric Sciences, University of Bari, Bari, Italy
| | - Davide Seripa
- Geriatric Unit & Gerontology-Geriatric Research Laboratory, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013, San Giovanni Rotondo, Foggia, Italy
| | - Alberto Pilotto
- Geriatric Unit & Gerontology-Geriatric Research Laboratory, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013, San Giovanni Rotondo, Foggia, Italy
- Geriatrics Unit, Azienda ULSS 16 Padova, S Antonio Hospital, Padova, Italy
| | - Vincenzo Solfrizzi
- Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Bari, Italy
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156
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Alzheimer's disease. Transl Neurosci 2012. [DOI: 10.1017/cbo9780511980053.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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157
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Salomone S, Caraci F, Leggio GM, Fedotova J, Drago F. New pharmacological strategies for treatment of Alzheimer's disease: focus on disease modifying drugs. Br J Clin Pharmacol 2012; 73:504-17. [PMID: 22035455 DOI: 10.1111/j.1365-2125.2011.04134.x] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Current approved drug treatments for Alzheimer disease (AD) include cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and the NMDA receptor antagonist memantine. These drugs provide symptomatic relief but poorly affect the progression of the disease. Drug discovery has been directed, in the last 10 years, to develop 'disease modifying drugs' hopefully able to counteract the progression of AD. Because in a chronic, slow progressing pathological process, such as AD, an early start of treatment enhances the chance of success, it is crucial to have biomarkers for early detection of AD-related brain dysfunction, usable before clinical onset. Reliable early biomarkers need therefore to be prospectively tested for predictive accuracy, with specific cut off values validated in clinical practice. Disease modifying drugs developed so far include drugs to reduce β amyloid (Aβ) production, drugs to prevent Aβ aggregation, drugs to promote Aβ clearance, drugs targeting tau phosphorylation and assembly and other approaches. Unfortunately none of these drugs has demonstrated efficacy in phase 3 studies. The failure of clinical trials with disease modifying drugs raises a number of questions, spanning from methodological flaws to fundamental understanding of AD pathophysiology and biology. Recently, new diagnostic criteria applicable to presymptomatic stages of AD have been published. These new criteria may impact on drug development, such that future trials on disease modifying drugs will include populations susceptible to AD, before clinical onset. Specific problems with completed trials and hopes with ongoing trials are discussed in this review.
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Affiliation(s)
- Salvatore Salomone
- Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry Department of Formative Processes, University of Catania, Viale Andrea Doria 6, Catania, Italy
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158
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Panza F, Frisardi V, Solfrizzi V, Imbimbo BP, Logroscino G, Santamato A, Greco A, Seripa D, Pilotto A. Immunotherapy for Alzheimer's disease: from anti-β-amyloid to tau-based immunization strategies. Immunotherapy 2012; 4:213-38. [PMID: 22339463 DOI: 10.2217/imt.11.170] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The exact mechanisms leading to Alzheimer's disease (AD) are largely unknown, limiting the identification of effective disease-modifying therapies. The two principal neuropathological hallmarks of AD are extracellular β-amyloid (Aβ), peptide deposition (senile plaques) and intracellular neurofibrillary tangles containing hyperphosphorylated tau protein. During the last decade, most of the efforts of the pharmaceutical industry were directed against the production and accumulation of Aβ. The most innovative of the pharmacological approaches was the stimulation of Aβ clearance from the brain of AD patients via the administration of Aβ antigens (active vaccination) or anti-Aβ antibodies (passive vaccination). Several active and passive anti-Aβ vaccines are under clinical investigation. Unfortunately, the first active vaccine (AN1792, consisting of preaggregate Aβ and an immune adjuvant, QS-21) was abandoned because it caused meningoencephalitis in approximately 6% of treated patients. Anti-Aβ monoclonal antibodies (bapineuzumab and solanezumab) are now being developed. The clinical results of the initial studies with bapineuzumab were equivocal in terms of cognitive benefit. The occurrence of vasogenic edema after bapineuzumab, and more rarely brain microhemorrhages (especially in Apo E ε4 carriers), has raised concerns on the safety of these antibodies directed against the N-terminus of the Aβ peptide. Solanezumab, a humanized anti-Aβ monoclonal antibody directed against the midregion of the Aβ peptide, was shown to neutralize soluble Aβ species. Phase II studies showed a good safety profile of solanezumab, while studies on cerebrospinal and plasma biomarkers documented good signals of pharmacodynamic activity. Although some studies suggested that active immunization may be effective against tau in animal models of AD, very few studies regarding passive immunization against tau protein are currently available. The results of the large, ongoing Phase III trials with bapineuzumab and solanezumab will tell us if monoclonal anti-Aβ antibodies may slow down the rate of deterioration of AD. Based on the new diagnostic criteria of AD and on recent major failures of anti-Aβ drugs in mild-to-moderate AD patients, one could argue that clinical trials on potential disease-modifying drugs, including immunological approaches, should be performed in the early stages of AD.
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Affiliation(s)
- Francesco Panza
- Geriatric Unit & Gerontology-Geriatric Research Laboratory, IRCCS Casa Sollievo della Sofferenza, Foggia, Italy.
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159
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Imbimbo BP, Ottonello S, Frisardi V, Solfrizzi V, Greco A, Seripa D, Pilotto A, Panza F. Solanezumab for the treatment of mild-to-moderate Alzheimer's disease. Expert Rev Clin Immunol 2012; 8:135-49. [PMID: 22288451 DOI: 10.1586/eci.11.93] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Solanezumab (LY2062430) is a humanized monoclonal antibody that binds to the central region of β-amyloid, a peptide believed to play a key role in the pathogenesis of Alzheimer's disease (AD). Eli Lilly & Co is developing an intravenous formulation of solanezumab for the treatment of mild-to-moderate AD. Acute and subchronic treatment with solanezumab of transgenic mice attenuated or reversed memory deficits with no effects on incidence or severity of cerebral amyloid angiopathy-associated microhemorrhages, a severe side effect associated with bapineuzumab, another monoclonal antibody. Phase II studies in AD patients have shown a good safety profile with encouraging indications on cerebrospinal and plasma biomarkers. The drug is currently being investigated in Phase III trials. While there is a strong hope that solanezumab may represent the first effective passive vaccine for AD treatment, skepticism still exists on the ability of the drug to slow the rate of deterioration in patients with fully established disease.
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Affiliation(s)
- Bruno P Imbimbo
- Research and Development Department, Chiesi Farmaceutici, Parma, Italy.
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160
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Basak JM, Kim J, Pyatkivskyy Y, Wildsmith KR, Jiang H, Parsadanian M, Patterson BW, Bateman RJ, Holtzman DM. Measurement of apolipoprotein E and amyloid β clearance rates in the mouse brain using bolus stable isotope labeling. Mol Neurodegener 2012; 7:14. [PMID: 22512932 PMCID: PMC3405485 DOI: 10.1186/1750-1326-7-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Accepted: 04/18/2012] [Indexed: 11/13/2022] Open
Abstract
Background Abnormal proteostasis due to alterations in protein turnover has been postulated to play a central role in several neurodegenerative diseases. Therefore, the development of techniques to quantify protein turnover in the brain is critical for understanding the pathogenic mechanisms of these diseases. We have developed a bolus stable isotope-labeling kinetics (SILK) technique coupled with multiple reaction monitoring mass spectrometry to measure the clearance of proteins in the mouse brain. Results Cohorts of mice were pulse labeled with 13 C6-leucine and the brains were isolated after pre-determined time points. The extent of label incorporation was measured over time using mass spectrometry to measure the ratio of labeled to unlabeled apolipoprotein E (apoE) and amyloid β (Aβ). The fractional clearance rate (FCR) was then calculated by analyzing the time course of disappearance for the labeled protein species. To validate the technique, apoE clearance was measured in mice that overexpress the low-density lipoprotein receptor (LDLR). The FCR in these mice was 2.7-fold faster than wild-type mice. To demonstrate the potential of this technique for understanding the pathogenesis of neurodegenerative disease, we applied our SILK technique to determine the effect of ATP binding cassette A1 (ABCA1) on both apoE and Aβ clearance. ABCA1 had previously been shown to regulate both the amount of apoE in the brain, along with the extent of Aβ deposition, and represents a potential molecular target for lowering brain amyloid levels in Alzheimer's disease patients. The FCR of apoE was increased by 1.9- and 1.5-fold in mice that either lacked or overexpressed ABCA1, respectively. However, ABCA1 had no effect on the FCR of Aβ, suggesting that ABCA1 does not regulate Aβ metabolism in the brain. Conclusions Our SILK strategy represents a straightforward, cost-effective, and efficient method to measure the clearance of proteins in the mouse brain. We expect that this technique will be applicable to the study of protein dynamics in the pathogenesis of several neurodegenerative diseases, and could aid in the evaluation of novel therapeutic agents.
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Affiliation(s)
- Jacob M Basak
- Department of Neurology, Saint Louis, Missouri 63110, USA
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161
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Tai LM, Jacobsen H, Ozmen L, Flohr A, Jakob-Roetne R, Caruso A, Grimm HP. The dynamics of Aβ distribution after γ-secretase inhibitor treatment, as determined by experimental and modelling approaches in a wild type rat. J Pharmacokinet Pharmacodyn 2012; 39:227-37. [PMID: 22481485 DOI: 10.1007/s10928-012-9246-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 03/01/2012] [Indexed: 12/28/2022]
Abstract
Inhibition of the enzyme(s) that produce the Amyloid beta (Aβ) peptide, namely BACE and γ-secretase, is considered an attractive target for Alzheimer's disease therapy. However, the optimal pharmacokinetic-pharmacodynamic modelling method to describe the changes in Aβ levels after drug treatment is unclear. In this study, turnover models were employed to describe Aβ levels following treatment with the γ-secretase inhibitor RO5036450, in the wild type rat. Initially, Aβ level changes in the brain, cerebral spinal fluid (CSF) and plasma were modeled as separate biological compartments, which allowed the estimation of a compound IC₅₀ and Aβ turnover. While the data were well described, the model did not take into consideration that the CSF pool of Aβ most likely originates from the brain via the CSF drainage pathway. Therefore, a separate model was carried out, with the assumption that CSF Aβ levels originated from the brain. The optimal model that described the data involved two brain Aβ 40 sub-compartments, one with a rapid turnover, from which CSF Aβ 40 is derived, and a second quasi-static pool of ~20%. Importantly, the estimated in vivo brain IC₅₀ was in a good range of the in vitro IC₅₀ (ratio, 1.4). In conclusion, the PK/PD models presented here are well suited for describing the temporal changes in Aβ levels that occur after treatment with an Aβ lowering drug, and identifying physiological parameters.
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Affiliation(s)
- Leon M Tai
- Preclinical Modeling and Simulation and Preclinical CNS Research Departments, F. Hoffmann-La Roche Ltd, Basel, Switzerland
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162
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Slats D, Claassen JA, Spies PE, Borm G, Besse KT, van Aalst W, Tseng J, Sjögren MJ, Olde Rikkert MG, Verbeek MM. Hourly variability of cerebrospinal fluid biomarkers in Alzheimer's disease subjects and healthy older volunteers. Neurobiol Aging 2012; 33:831.e1-9. [DOI: 10.1016/j.neurobiolaging.2011.07.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 06/17/2011] [Accepted: 07/12/2011] [Indexed: 11/16/2022]
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163
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Hampel H, Prvulovic D. Are biomarkers harmful to recruitment and retention in Alzheimer's disease clinical trials? An international perspective. J Nutr Health Aging 2012; 16:346-8. [PMID: 22499455 DOI: 10.1007/s12603-012-0021-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Clinical trials in Alzheimer's disease (AD) do not only generate high costs but have also been of little success within recent years. The failure of several large phase III clinical trials on highly promising disease modifying compounds calls for a critical reflection on potential reasons and counter-measures. The recent introduction of new diagnostic criteria of AD and the development and validation of diagnostic and predictive AD biomarkers allows enriching study populations, reducing variance, and improving statistical power of trials while even opening the possibility to reduce total study costs. While CSF or extensive imaging biomarkers might adversely affect retention in clinical trials, their careful application will unlikely reduce adherence. Regulatory authorities are generally supportive of biomarker use in clinical trials but potential consequences of biomarker based patient selection on the generalizability of trial results need careful evaluation.
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Affiliation(s)
- H Hampel
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University of Frankfurt, Frankfurt, Germany.
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164
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Tayeb HO, Yang HD, Price BH, Tarazi FI. Pharmacotherapies for Alzheimer's disease: Beyond cholinesterase inhibitors. Pharmacol Ther 2012; 134:8-25. [DOI: 10.1016/j.pharmthera.2011.12.002] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 12/31/2022]
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165
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Yao J, Brinton RD. Targeting mitochondrial bioenergetics for Alzheimer's prevention and treatment. Curr Pharm Des 2012; 17:3474-9. [PMID: 21902662 DOI: 10.2174/138161211798072517] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 08/17/2011] [Indexed: 01/31/2023]
Abstract
Alzheimer's is a neurodegenerative disease with a complex and progressive pathological phenotype characterized first by hypometabolism and impaired mitochondrial bioenergetics followed by pathological burden. The progressive and multifaceted degenerative phenotype of Alzheimer's suggests that successful treatment strategies necessarily will be equally multi-faceted and disease stage specific. Traditional therapeutic strategies based on the pathological aspect of the disease have achieved success in preclinical models which has not translated into clinical therapeutic efficacy. Meanwhile, increasing evidence indicates an antecedent and potentially causal role of mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress in AD pathogenesis. The essential role of mitochondrial bioenergetics and the unique trajectory of alterations in brain metabolic capacity enable a bioenergetic- centric strategy that targets disease-stage specific pattern of brain metabolism for disease prevention and treatment. A combination of nutraceutical and pharmaceutical intervention that enhances glucose-driven metabolic activity and potentiates mitochondrial bioenergetic function could prevent the antecedent decline in brain glucose metabolism, promote healthy aging and prevent AD. Alternatively, during the prodromal incipient phase of AD, sustained activation of ketogenic metabolic pathways coupled with supplement of the alternative fuel source, ketone bodies, could sustain mitochondrial bioenergetic function to prevent or delay further progression of the disease.
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Affiliation(s)
- Jia Yao
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, 90033, USA
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166
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Li T, Huang Y, Jin S, Ye L, Rong N, Yang X, Ding Y, Cheng Z, Zhang J, Wan Z, Harrison DC, Hussain I, Hall A, Lee DHS, Lau LF, Matsuoka Y. Γ-secretase modulators do not induce Aβ-rebound and accumulation of β-C-terminal fragment. J Neurochem 2012; 121:277-86. [PMID: 22035227 DOI: 10.1111/j.1471-4159.2011.07560.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
γ-secretase inhibitors (GSIs) have been developed to reduce amyloid-β (Aβ) production for the treatment of Alzheimer's disease by inhibiting the cleavage of amyloid precursor protein (APP). However, cross-inhibitory activity on the processing of Notch can cause adverse reactions. To avoid these undesirable effects, γ-secretase modulators (GSMs) are being developed to selectively reduce toxic Aβ production without perturbing Notch signaling. As it is also known that GSIs can cause a paradoxical increase of plasma Aβ over the baseline after a transient reduction (known as Aβ-rebound), we asked if GSMs would cause a similar rebound and what the potential mechanism might be. Our studies were performed with one GSI (LY-450139) and two chemically distinct GSMs. Although LY-450139 caused Aβ-rebound as expected in rat plasma, the two GSMs did not. Inhibition of APP processing by LY-450139 induced an accumulation of γ-secretase substrates, α- and β-C-terminal fragments of APP, but neither GSM caused such an accumulation. In conclusion, we discover that GSMs, unlike GSIs, do not cause Aβ-rebound, possibly because of the lack of accumulation of β-C-terminal fragments. GSMs may be superior to GSIs in the treatment of Alzheimer's disease not only by sparing Notch signaling but also by avoiding Aβ-rebound.
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Affiliation(s)
- Ting Li
- Neurodegeneration Research, R&D China, GlaxoSmithKline, Shanghai, China
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167
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Shoji M. Molecular approaches to the treatment, prophylaxis, and diagnosis of Alzheimer's disease: clinical molecular and genetic studies on Alzheimer's disease. J Pharmacol Sci 2012; 118:345-9. [PMID: 22382661 DOI: 10.1254/jphs.11r13fm] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Recent advances in clinical molecular and genetic studies on Alzheimer's disease (AD) are summarized here. Cerebrospinal fluid (CSF) Aβ42 and tau are the most sensitive biomarkers for the diagnosis of AD and prediction of its onset following mild cognitive impairment (MCI). Based on this progress, new diagnostic criteria for AD dementia, MCI due to AD, and preclinical AD were proposed by the National Institute of Aging (NIA) and Alzheimer's Association (AA) in April 2011. In these new criteria, progress in CSF biomarker and amyloid imaging studies over the past 10 years has added to critical information. The marked contributions of basic and clinical studies have established clinical evidence supporting these markers. Based on this progress, essential curative therapy for AD is urgently expected.
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Affiliation(s)
- Mikio Shoji
- Department of Neurology, Hirosaki University Graduate School of Medicine, 5 Zaifucho, Hirosaki, Aomori 036-8216, Japan.
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168
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Multicenter, Randomized, Double-Blind, Placebo-Controlled, Single-Ascending Dose Study of the Oral γ-Secretase Inhibitor BMS-708163 (Avagacestat): Tolerability Profile, Pharmacokinetic Parameters, and Pharmacodynamic Markers. Clin Ther 2012; 34:654-67. [DOI: 10.1016/j.clinthera.2012.01.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/11/2012] [Accepted: 01/26/2012] [Indexed: 01/26/2023]
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169
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Cisterna magna cannulated repeated CSF sampling rat model – effects of a gamma-secretase inhibitor on Aβ levels. J Neurosci Methods 2012; 205:36-44. [DOI: 10.1016/j.jneumeth.2011.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 11/17/2022]
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170
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Andreasson U, Portelius E, Pannee J, Zetterberg H, Blennow K. Multiplexing and multivariate analysis in neurodegeneration. Methods 2012; 56:464-70. [PMID: 22391487 DOI: 10.1016/j.ymeth.2012.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 10/28/2022] Open
Abstract
Limited sample volume is often an obstacle in clinical research and one way to circumvent this is to use multiplex techniques where several different analytes are simultaneously measured. There is a multitude of different platforms that can be used for multiplexing and their uniqueness and similarities will be described. Multivariate analysis is a powerful tool for extracting information from multiplex data. An introduction to one such algorithm is presented followed by examples from the literature, in the field of neurodegeneration, where multiplex and multivariate methods have been used.
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Affiliation(s)
- Ulf Andreasson
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.
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171
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Mattsson N, Portelius E, Blennow K, Zetterberg H. Cerebrospinal fluid biomarkers to monitor treatment effects in Alzheimer’s disease and related conditions. Neurodegener Dis Manag 2012. [DOI: 10.2217/nmt.11.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
SUMMARY Neurodegenerative and neuroinflammatory conditions are major causes of morbidity and mortality worldwide. To support the development of effective treatments, and to increase the understanding of disease mechanisms, much focus has been directed towards identifying biomarkers of treatment effects in these conditions. Cerebrospinal fluid has been extensively utilized for this purpose. For example, researchers now have candidate cerebrospinal fluid biomarkers to identify pharmacodynamic effects on β-amyloid metabolism in Alzheimer’s disease, and downstream effects on axonal loss in several neurological diseases. Here we describe candidate markers that potentially may be implemented as pharmacodynamic markers in clinical trials and routine clinical settings.
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Affiliation(s)
- Niklas Mattsson
- Clinical Neurochemistry Laboratory, Institute of Neuroscience & Physiology, Department of Psychiatry & Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Erik Portelius
- Clinical Neurochemistry Laboratory, Institute of Neuroscience & Physiology, Department of Psychiatry & Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Institute of Neuroscience & Physiology, Department of Psychiatry & Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Institute of Neuroscience & Physiology, Department of Psychiatry & Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
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172
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Savonenko AV, Melnikova T, Hiatt A, Li T, Worley PF, Troncoso JC, Wong PC, Price DL. Alzheimer's therapeutics: translation of preclinical science to clinical drug development. Neuropsychopharmacology 2012; 37:261-77. [PMID: 21937983 PMCID: PMC3238084 DOI: 10.1038/npp.2011.211] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 08/16/2011] [Accepted: 08/16/2011] [Indexed: 12/15/2022]
Abstract
Over the past three decades, significant progress has been made in understanding the neurobiology of Alzheimer's disease. In recent years, the first attempts to implement novel mechanism-based treatments brought rather disappointing results, with low, if any, drug efficacy and significant side effects. A discrepancy between our expectations based on preclinical models and the results of clinical trials calls for a revision of our theoretical views and questions every stage of translation-from how we model the disease to how we run clinical trials. In the following sections, we will use some specific examples of the therapeutics from acetylcholinesterase inhibitors to recent anti-Aβ immunization and γ-secretase inhibition to discuss whether preclinical studies could predict the limitations in efficacy and side effects that we were so disappointed to observe in recent clinical trials. We discuss ways to improve both the predictive validity of mouse models and the translation of knowledge between preclinical and clinical stages of drug development.
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Affiliation(s)
- Alena V Savonenko
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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173
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Watanabe KI, Ishikawa C, Kuwahara H, Sato K, Komuro S, Nakagawa T, Nomura N, Watanabe S, Yabuki M. A new methodology for simultaneous quantification of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 by column-switching LC/MS/MS. Anal Bioanal Chem 2011; 402:2033-42. [PMID: 22200927 DOI: 10.1007/s00216-011-5648-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/07/2011] [Accepted: 12/07/2011] [Indexed: 10/14/2022]
Abstract
This article details the development of a novel method that overcomes the drawbacks of sandwich ELISA (sELISA) and allows reliable evaluation of simultaneous quantification of the amyloid (Aβ)-peptides, total-Aβ, Aβx-38, Aβx-40, and Aβx-42, in rat brain by optimized sample purification and column-switching liquid chromatographic-tandem mass spectrometry (LC/MS/MS). This method provides accurate analyses of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 with a linear calibration range between 0.05 and 45 ng/mL. Verification for accuracy and precision of biological samples were determined by a standard addition and recovery test, spiked with synthetic Aβ1-38, Aβ1-40, and Aβ1-42 into the rat brain homogenate. This method showed <20% relative error and relative standard deviation, indicating high reproducibility and reliability. The brain concentrations of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 after oral administration of flurbiprofen in rats were measured by this method. Aβx-42 concentrations (4.57 ± 0.69 ng/g) in rats administered flurbiprofen were lower than those in untreated rats (6.48 ± 0.93 ng/g). This was consistent with several reports demonstrating that NSAIDs reduced the generation of Aβ. We report here a method that allows not only the quantification of specific molecular species of Aβ but also simultaneous quantification of total-Aβ, Aβx-38, Aβx-40, and Aβx-42, thus overcoming the drawbacks of sELISA.
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Affiliation(s)
- Ken-ichi Watanabe
- Pharmacokinetics Research Laboratory, Dainippon Sumitomo Pharmaceutical Co., Ltd., Suita-shi, Osaka, Japan.
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174
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D'Onofrio G, Panza F, Frisardi V, Solfrizzi V, Imbimbo BP, Paroni G, Cascavilla L, Seripa D, Pilotto A. Advances in the identification of γ-secretase inhibitors for the treatment of Alzheimer's disease. Expert Opin Drug Discov 2011; 7:19-37. [DOI: 10.1517/17460441.2012.645534] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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175
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Sun ZY, Asberom T, Bara T, Bennett C, Burnett D, Chu I, Clader J, Cohen-Williams M, Cole D, Czarniecki M, Durkin J, Gallo G, Greenlee W, Josien H, Huang X, Hyde L, Jones N, Kazakevich I, Li H, Liu X, Lee J, MacCoss M, Mandal MB, McCracken T, Nomeir A, Mazzola R, Palani A, Parker EM, Pissarnitski DA, Qin J, Song L, Terracina G, Vicarel M, Voigt J, Xu R, Zhang L, Zhang Q, Zhao Z, Zhu X, Zhu Z. Cyclic Hydroxyamidines as Amide Isosteres: Discovery of Oxadiazolines and Oxadiazines as Potent and Highly Efficacious γ-Secretase Modulators in Vivo. J Med Chem 2011; 55:489-502. [DOI: 10.1021/jm201407j] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhong-Yue Sun
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Theodros Asberom
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Thomas Bara
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Chad Bennett
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Duane Burnett
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Inhou Chu
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - John Clader
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Mary Cohen-Williams
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - David Cole
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Michael Czarniecki
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - James Durkin
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Gioconda Gallo
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - William Greenlee
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Hubert Josien
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Xianhai Huang
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Lynn Hyde
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Nicholas Jones
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Irina Kazakevich
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Hongmei Li
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Xiaoxiang Liu
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Julie Lee
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Malcolm MacCoss
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Mihir B. Mandal
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Troy McCracken
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Amin Nomeir
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Robert Mazzola
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Anandan Palani
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Eric M. Parker
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Dmitri A. Pissarnitski
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Jun Qin
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Lixin Song
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Giuseppe Terracina
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Monica Vicarel
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Johannes Voigt
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Ruo Xu
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Lili Zhang
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Qi Zhang
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Zhiqiang Zhao
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Xiaohong Zhu
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
| | - Zhaoning Zhu
- Department
of Medicinal Chemistry, §Department of Neuroscience, ∥Department of Structural Chemistry, ⊥Department of Pharmaceutical
Sciences, and #Department of Drug Metabolism and Pharmacokinetics, Schering Plough Research Institute, 2015 Galloping
Hill Road, Kenilworth, New Jersey 07033, United States
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176
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Hampel H, Wilcock G, Andrieu S, Aisen P, Blennow K, Broich K, Carrillo M, Fox NC, Frisoni GB, Isaac M, Lovestone S, Nordberg A, Prvulovic D, Sampaio C, Scheltens P, Weiner M, Winblad B, Coley N, Vellas B. Biomarkers for Alzheimer's disease therapeutic trials. Prog Neurobiol 2011; 95:579-93. [PMID: 21130138 DOI: 10.1016/j.pneurobio.2010.11.005] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/10/2010] [Accepted: 11/22/2010] [Indexed: 11/26/2022]
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177
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Garcia-Alloza M, Gregory J, Kuchibhotla KV, Fine S, Wei Y, Ayata C, Frosch MP, Greenberg SM, Bacskai BJ. Cerebrovascular lesions induce transient β-amyloid deposition. Brain 2011; 134:3697-707. [PMID: 22120142 DOI: 10.1093/brain/awr300] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previous clinical studies have documented a close relationship between cerebrovascular disease and risk of Alzheimer's disease. We examined possible mechanistic interactions through use of experimental stroke models in a transgenic mouse model of β-amyloid deposition (APPswe/PS1dE9). Following middle cerebral artery occlusion, we observed a rapid increase in amyloid plaque burden in the region surrounding the infarction. In human tissue samples, however, we were unable to detect a localized increase in amyloid burden adjacent to cerebral infarcts. To resolve this discrepancy, we generated cerebral microstrokes in amyloid precursor protein mouse models with the photosensitive dye Rose bengal, and monitored plaque formation in real time using multiphoton microscopy. We observed a striking increase in the number of new plaques and amyloid angiopathy in the area immediately surrounding the infarcted area; however, the effect was transient, potentially resolving the discord between mouse and human tissue. We did not detect changes in candidate proteins related to β-amyloid generation or degradation such as β-amyloid-converting enzyme, amyloid precursor protein, presenilin 1, neprylisin or insulin-degrading enzyme. Together, these results demonstrate that strokes can trigger accelerated amyloid deposition, most likely through interference with amyloid clearance pathways. Additionally, this study indicates that focal ischaemia provides an experimental paradigm in which to study the mechanisms of plaque seeding and growth.
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Affiliation(s)
- Monica Garcia-Alloza
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114 16th Street, Charlestown, MA 02129, USA
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178
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May PC, Dean RA, Lowe SL, Martenyi F, Sheehan SM, Boggs LN, Monk SA, Mathes BM, Mergott DJ, Watson BM, Stout SL, Timm DE, Smith LaBell E, Gonzales CR, Nakano M, Jhee SS, Yen M, Ereshefsky L, Lindstrom TD, Calligaro DO, Cocke PJ, Greg Hall D, Friedrich S, Citron M, Audia JE. Robust central reduction of amyloid-β in humans with an orally available, non-peptidic β-secretase inhibitor. J Neurosci 2011; 31:16507-16. [PMID: 22090477 PMCID: PMC6633289 DOI: 10.1523/jneurosci.3647-11.2011] [Citation(s) in RCA: 288] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Revised: 09/01/2011] [Accepted: 09/09/2011] [Indexed: 01/02/2023] Open
Abstract
According to the amyloid cascade hypothesis, cerebral deposition of amyloid-β peptide (Aβ) is critical for Alzheimer's disease (AD) pathogenesis. Aβ generation is initiated when β-secretase (BACE1) cleaves the amyloid precursor protein. For more than a decade, BACE1 has been a prime target for designing drugs to prevent or treat AD. However, development of such agents has turned out to be extremely challenging, with major hurdles in cell penetration, oral bioavailability/metabolic clearance, and brain access. Using a fragment-based chemistry strategy, we have generated LY2811376 [(S)-4-(2,4-difluoro-5-pyrimidin-5-yl-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]thiazin-2-ylamine], the first orally available non-peptidic BACE1 inhibitor that produces profound Aβ-lowering effects in animals. The biomarker changes obtained in preclinical animal models translate into man at doses of LY2811376 that were safe and well tolerated in healthy volunteers. Prominent and long-lasting Aβ reductions in lumbar CSF were measured after oral dosing of 30 or 90 mg of LY2811376. This represents the first translation of BACE1-driven biomarker changes in CNS from preclinical animal models to man. Because of toxicology findings identified in longer-term preclinical studies, this compound is no longer progressing in clinical development. However, BACE1 remains a viable target because the adverse effects reported here were recapitulated in LY2811376-treated BACE1 KO mice and thus are unrelated to BACE1 inhibition. The magnitude and duration of central Aβ reduction obtainable with BACE1 inhibition positions this protease as a tractable small-molecule target through which to test the amyloid hypothesis in man.
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Affiliation(s)
- Patrick C. May
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Robert A. Dean
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Stephen L. Lowe
- Lilly–National University of Singapore Centre for Clinical Pharmacology, Singapore 117597, Singapore
| | - Ferenc Martenyi
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Scott M. Sheehan
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Leonard N. Boggs
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Scott A. Monk
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Brian M. Mathes
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Dustin J. Mergott
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Brian M. Watson
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Stephanie L. Stout
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - David E. Timm
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | | | | | | | - Stanford S. Jhee
- PAREXEL International Early Phase Los Angeles, Glendale, California 91206
| | - Mark Yen
- PAREXEL International Early Phase Los Angeles, Glendale, California 91206
- California Clinical Trials Medical Group, Glendale, California 91206, and
| | - Larry Ereshefsky
- PAREXEL International Early Phase Los Angeles, Glendale, California 91206
- University of Texas Health Science Center, San Antonio, Texas 98284
| | - Terry D. Lindstrom
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - David O. Calligaro
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Patrick J. Cocke
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - D. Greg Hall
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Stuart Friedrich
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - Martin Citron
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
| | - James E. Audia
- Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, Indiana 46285
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179
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Standardization of preanalytical aspects of cerebrospinal fluid biomarker testing for Alzheimer's disease diagnosis: a consensus paper from the Alzheimer's Biomarkers Standardization Initiative. Alzheimers Dement 2011; 8:65-73. [PMID: 22047631 DOI: 10.1016/j.jalz.2011.07.004] [Citation(s) in RCA: 240] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 07/28/2011] [Indexed: 11/21/2022]
Abstract
BACKGROUND Numerous studies show that the cerebrospinal fluid biomarkers total tau (T-tau), tau phosphorylated at threonine 181 (P-tau(181P)), and amyloid-β (1-42) (Aβ(1-42)) have high diagnostic accuracy for Alzheimer's disease. Variability in concentrations for Aβ(1-42), T-tau, and P-tau(181P) drives the need for standardization. METHODS Key issues were identified and discussed before the first meeting of the members of the Alzheimer's Biomarkers Standardization Initiative (ABSI). Subsequent ABSI consensus meetings focused on preanalytical issues. RESULTS Consensus was reached on preanalytical issues such as the effects of fasting, different tube types, centrifugation, time and temperature before storage, storage temperature, repeated freeze/thaw cycles, and length of storage on concentrations of Aβ(1-42), T-tau, and P-tau(181P) in cerebrospinal fluid. CONCLUSIONS The consensus reached on preanalytical issues and the recommendations put forward during the ABSI consensus meetings are presented in this paper.
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Jämsä A, Belda O, Edlund M, Lindström E. BACE-1 inhibition prevents the γ-secretase inhibitor evoked Aβ rise in human neuroblastoma SH-SY5Y cells. J Biomed Sci 2011; 18:76. [PMID: 22018341 PMCID: PMC3217850 DOI: 10.1186/1423-0127-18-76] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 10/21/2011] [Indexed: 01/05/2023] Open
Abstract
Background Accumulation of amyloid β-peptide (Aβ) in the plaques is one of the major pathological features in Alzheimer's disease (AD). Sequential cleavage of amyloid precursor protein (APP) by β-site APP cleaving enzyme 1 (BACE-1) and γ-secretase results in the formation of Aβ peptides. Preventing Aβ formation is believed to attenuate AD progression and BACE-1 and γ-secretase are thus attractive targets for AD drug development. Methods Combining BACE-1 and γ-secretase inhibition on Aβ secretion from human neuroblastoma SH-SY5Y cells was evaluated in this study. Secreted Aβ40 and Aβ42 levels were measured from SH-SY5Y cells stably transfected with APPwt or APPswe genes. A selective BACE inhibitor and the γ-secretase inhibitor LY450139 (semagacestat) were used to inhibit respective secretase. Results LY450139 increased Aβ40 and Aβ42 secretion from SH-SY5Y APPwt cells at low concentrations (by 60% at 3 nM) followed by subsequent inhibition at higher concentrations (IC50 90 nM). Washout studies showed that the Aβ increase evoked by 3 nM LY450139 was not due to enhanced cleavage following substrate accumulation but rather to activation of Aβ formation. By contrast, LY450139 inhibited Aβ formation from SH-SY5Y APPswe in a monophasic manner (IC50 18 nM). The BACE inhibitor per se inhibited Aβ secretion from both SH-SY5Y APPwt and SH-SY5Y APPswe cells with IC50s ranging between 7 - 18 nM and also prevented the increased Aβ secretion evoked by 3 nM LY450139. Combining the BACE inhibitor with higher inhibitory concentrations of LY450139 failed to demonstrate any clear additive or synergistic effects. Conclusion BACE-1 inhibition attenuates the Aβ increase evoked by LY450139 while not providing any obvious synergistic effects on LY450139-mediated inhibition.
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Fractional synthesis and clearance rates for amyloid β. Nat Med 2011; 17:1178-9; author reply 1179-80. [PMID: 21988985 DOI: 10.1038/nm.2495] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
In recent years, advances in Alzheimer's disease (AD) biomarker research have provided powerful tools to improve trial design. In particular, biomarkers provide powerful methods for the selection of individuals with Alzheimer's disease prior to the onset of dementia. Data suggest that neuroimaging biomarkers will be useful as endpoints for trials in very early, even asymptomatic disease, though further work is necessary to establish validity for regulatory purposes.
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Herrmann N, Chau SA, Kircanski I, Lanctôt KL. Current and Emerging Drug Treatment Options for Alzheimerʼs Disease. Drugs 2011; 71:2031-65. [DOI: 10.2165/11595870-000000000-00000] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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185
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Shineman DW, Basi GS, Bizon JL, Colton CA, Greenberg BD, Hollister BA, Lincecum J, Leblanc GG, Lee L(BH, Luo F, Morgan D, Morse I, Refolo LM, Riddell DR, Scearce-Levie K, Sweeney P, Yrjänheikki J, Fillit HM. Accelerating drug discovery for Alzheimer's disease: best practices for preclinical animal studies. Alzheimers Res Ther 2011; 3:28. [PMID: 21943025 PMCID: PMC3218805 DOI: 10.1186/alzrt90] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Animal models have contributed significantly to our understanding of the underlying biological mechanisms of Alzheimer's disease (AD). As a result, over 300 interventions have been investigated and reported to mitigate pathological phenotypes or improve behavior in AD animal models or both. To date, however, very few of these findings have resulted in target validation in humans or successful translation to disease-modifying therapies. Challenges in translating preclinical studies to clinical trials include the inability of animal models to recapitulate the human disease, variations in breeding and colony maintenance, lack of standards in design, conduct and analysis of animal trials, and publication bias due to under-reporting of negative results in the scientific literature. The quality of animal model research on novel therapeutics can be improved by bringing the rigor of human clinical trials to animal studies. Research communities in several disease areas have developed recommendations for the conduct and reporting of preclinical studies in order to increase their validity, reproducibility, and predictive value. To address these issues in the AD community, the Alzheimer's Drug Discovery Foundation partnered with Charles River Discovery Services (Morrisville, NC, USA) and Cerebricon Ltd. (Kuopio, Finland) to convene an expert advisory panel of academic, industry, and government scientists to make recommendations on best practices for animal studies testing investigational AD therapies. The panel produced recommendations regarding the measurement, analysis, and reporting of relevant AD targets, th choice of animal model, quality control measures for breeding and colony maintenance, and preclinical animal study design. Major considerations to incorporate into preclinical study design include a priori hypotheses, pharmacokinetics-pharmacodynamics studies prior to proof-of-concept testing, biomarker measurements, sample size determination, and power analysis. The panel also recommended distinguishing between pilot 'exploratory' animal studies and more extensive 'therapeutic' studies to guide interpretation. Finally, the panel proposed infrastructure and resource development, such as the establishment of a public data repository in which both positive animal studies and negative ones could be reported. By promoting best practices, these recommendations can improve the methodological quality and predictive value of AD animal studies and make the translation to human clinical trials more efficient and reliable.
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Affiliation(s)
- Diana W Shineman
- Alzheimer's Drug Discovery Foundation, 57 West 57 Street, Suite 904, New York, NY 10019, USA
| | - Guriqbal S Basi
- Elan Pharmaceuticals, 1000 Gateway Boulevard, South San Francisco, CA 94080, USA
| | - Jennifer L Bizon
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, 100 S. Newell Drive, Gainesville, FL 32610-0244, USA
| | - Carol A Colton
- Duke University Medical Center, 201H Bryan Research Building, Research Drive, Durham, NC 27710, USA
| | - Barry D Greenberg
- University Health Network, Toronto Western Research Institute, 399 Bathurst Street, MP 14-328, Toronto, ON, M5T 2S8, Canada
| | - Beth A Hollister
- Charles River Discovery Services, 3300 Gateway Centre Boulevard, Morrisville, NC 27560, USA
| | - John Lincecum
- ALS Therapy Development Institute, 215 First Street, Cambridge, MA 02142, USA
| | | | - Linda (Bobbi) H Lee
- Alzheimer's Drug Discovery Foundation, 57 West 57 Street, Suite 904, New York, NY 10019, USA
- Columbia University, 630 West 168th Street, Building PS 12-510, New York, NY 10032, USA
| | - Feng Luo
- Abbott Neuroscience, AP4-2, 100 Abbott Park Road, Abbott Park, IL 60064-6076, USA
| | - Dave Morgan
- USF Health Byrd Alzheimer Institute, University of South Florida, 4001 E. Fletcher Avenue, MDC Box 36, Tampa FL 33613, USA
| | - Iva Morse
- Genetically Engineered Models and Services/Charles River Laboratories, Inc., 251 Ballardvale Street, Wilmington, MA 01887, USA
| | - Lorenzo M Refolo
- National Institute on Aging, 7201 Wisconsin Avenue, Gateway Building, Suite 350, Bethesda, MD 20892, USA
| | - David R Riddell
- Pfizer Neuroscience Research Unit, MS 8220-3414, Eastern Point Road, Groton, CT 06340, USA
| | | | - Patrick Sweeney
- Cerebricon Ltd./Charles River Discovery Services, Microkatu 1, Kuopio, Finland 70210
| | - Juha Yrjänheikki
- Cerebricon Ltd./Charles River Discovery Services, Microkatu 1, Kuopio, Finland 70210
| | - Howard M Fillit
- Alzheimer's Drug Discovery Foundation, 57 West 57 Street, Suite 904, New York, NY 10019, USA
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Lu Y, Zhang L, Nolan CE, Becker SL, Atchison K, Robshaw AE, Pustilnik LR, Osgood SM, Miller EH, Stepan AF, Subramanyam C, Efremov I, Hallgren AJ, Riddell D. Quantitative pharmacokinetic/pharmacodynamic analyses suggest that the 129/SVE mouse is a suitable preclinical pharmacology model for identifying small-molecule γ-secretase inhibitors. J Pharmacol Exp Ther 2011; 339:922-34. [PMID: 21930801 DOI: 10.1124/jpet.111.186791] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) poses a serious public health threat to the United States. Disease-modifying drugs slowing AD progression are in urgent need, but they are still unavailable. According to the amyloid cascade hypothesis, inhibition of β- or γ-secretase, key enzymes for the production of amyloid β (Aβ), may be viable mechanisms for the treatment of AD. For the discovery of γ-secretase inhibitors (GSIs), the APP-overexpressing Tg2576 mouse has been the preclinical model of choice, in part because of the ease of detection of Aβ species in its brain, plasma, and cerebrospinal fluid (CSF). Some biological observations and practical considerations, however, argue against the use of the Tg2576 mouse. We reasoned that an animal model would be suitable for GSI discovery if the pharmacokinetic (PK)/pharmacodynamic (PD) relationship of a compound for Aβ lowering in this model is predictive of that in human. In this study, we assessed whether the background 129/SVE strain is a suitable preclinical pharmacology model for identifying new GSIs by evaluating the translatability of the intrinsic PK/PD relationships for brain and CSF Aβ across the Tg2576 and 129/SVE mouse and human. Using semimechanistically based PK/PD modeling, our analyses indicated that the intrinsic PK/PD relationship for brain Aβx-42 and CSF Aβx-40 in the 129/SVE mouse is indicative of that for human CSF Aβ. This result, in conjunction with practical considerations, strongly suggests that the 129/SVE mouse is a suitable model for GSI discovery. Concurrently, the necessity and utilities of PK/PD modeling for rational interpretation of Aβ data are established.
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Affiliation(s)
- Yasong Lu
- Department of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Worldwide Research and Development, Eastern Point Road, Groton, CT 06340, USA
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Huang Y, Potter R, Sigurdson W, Santacruz A, Shih S, Ju YE, Kasten T, Morris JC, Mintun M, Duntley S, Bateman RJ. Effects of age and amyloid deposition on Aβ dynamics in the human central nervous system. ACTA ACUST UNITED AC 2011; 69:51-8. [PMID: 21911660 DOI: 10.1001/archneurol.2011.235] [Citation(s) in RCA: 194] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The amyloid hypothesis predicts that increased production or decreased clearance of β-amyloid (Aβ) leads to amyloidosis, which ultimately culminates in Alzheimer disease (AD). OBJECTIVE To investigate whether dynamic changes in Aβ levels in the human central nervous system may be altered by aging or by the pathology of AD and thus contribute to the risk of AD. DESIGN Repeated-measures case-control study. SETTING Washington University School of Medicine in St Louis, Missouri. PARTICIPANTS Participants with amyloid deposition, participants without amyloid deposition, and younger normal control participants. MAIN OUTCOME MEASURES In this study, hourly cerebrospinal fluid (CSF) Aβ concentrations were compared with age, status of amyloid deposition, electroencephalography, and video recording data. RESULTS Linear increases were observed over time in the Aβ levels in CSF samples obtained from the younger normal control participants and the older participants without amyloid deposition, but not from the older participants with amyloid deposition. Significant circadian patterns were observed in the Aβ levels in CSF samples obtained from the younger control participants; however, circadian amplitudes decreased in both older participants without amyloid deposition and older participants with amyloid deposition. Aβ diurnal concentrations were correlated with the amount of sleep but not with the various activities that the participants participated in while awake. CONCLUSIONS A reduction in the linear increase in the Aβ levels in CSF samples that is associated with amyloid deposition and a decreased CSF Aβ diurnal pattern associated with increasing age disrupt the normal physiology of Aβ dynamics and may contribute to AD.
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Affiliation(s)
- Yafei Huang
- Department of Neurology, Washington University School of Medicine, 660 S Euclid, PO Box 8111, St Louis, MO 63110, USA
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Gorelick PB, Scuteri A, Black SE, Decarli C, Greenberg SM, Iadecola C, Launer LJ, Laurent S, Lopez OL, Nyenhuis D, Petersen RC, Schneider JA, Tzourio C, Arnett DK, Bennett DA, Chui HC, Higashida RT, Lindquist R, Nilsson PM, Roman GC, Sellke FW, Seshadri S. Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association. Stroke 2011. [PMID: 21778438 DOI: 10.1161/str.0b013e3182299496.vascular] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
BACKGROUND AND PURPOSE This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment. METHODS Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee. RESULTS The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people. CONCLUSIONS Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.
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Gorelick PB, Scuteri A, Black SE, Decarli C, Greenberg SM, Iadecola C, Launer LJ, Laurent S, Lopez OL, Nyenhuis D, Petersen RC, Schneider JA, Tzourio C, Arnett DK, Bennett DA, Chui HC, Higashida RT, Lindquist R, Nilsson PM, Roman GC, Sellke FW, Seshadri S. Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association. Stroke 2011; 42:2672-713. [PMID: 21778438 PMCID: PMC3778669 DOI: 10.1161/str.0b013e3182299496] [Citation(s) in RCA: 2525] [Impact Index Per Article: 194.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment. METHODS Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee. RESULTS The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people. CONCLUSIONS Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.
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191
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The amyloid cascade hypothesis for Alzheimer's disease: an appraisal for the development of therapeutics. Nat Rev Drug Discov 2011; 10:698-712. [DOI: 10.1038/nrd3505] [Citation(s) in RCA: 1485] [Impact Index Per Article: 114.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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192
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Traumatic brain injury and amyloid-β pathology: a link to Alzheimer's disease? Nat Rev Neurosci 2011; 11:361-70. [PMID: 20216546 DOI: 10.1038/nrn2808] [Citation(s) in RCA: 415] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Traumatic brain injury (TBI) has devastating acute effects and in many cases seems to initiate long-term neurodegeneration. Indeed, an epidemiological association between TBI and the development of Alzheimer's disease (AD) later in life has been demonstrated, and it has been shown that amyloid-β (Aβ) plaques — one of the hallmarks of AD — may be found in patients within hours following TBI. Here, we explore the mechanistic underpinnings of the link between TBI and AD, focusing on the hypothesis that rapid Aβ plaque formation may result from the accumulation of amyloid precursor protein in damaged axons and a disturbed balance between Aβ genesis and catabolism following TBI.
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γ-secretase inhibitors for treating Alzheimer’s disease: rationale and clinical data. ACTA ACUST UNITED AC 2011. [DOI: 10.4155/cli.11.86] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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194
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Willis BA, Zhang W, Ayan-Oshodi M, Lowe SL, Annes WF, Sirois PJ, Friedrich S, de la Peña A. Semagacestat pharmacokinetics are not significantly affected by formulation, food, or time of dosing in healthy participants. J Clin Pharmacol 2011; 52:904-13. [PMID: 21724950 DOI: 10.1177/0091270011407195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Semagacestat, a γ-secretase inhibitor, reduces formation of amyloid beta peptide. Two single-dose (140 mg), open-label, randomized, 3-period, crossover studies evaluated the effect of formulation, food, and time of dosing on the pharmacokinetics and pharmacodynamics of semagacestat in healthy participants. The first study (n = 14) compared tablet to capsules. For all formulations, the median time to maximum plasma concentration (t(max)) was generally 1.0 hour. Plasma elimination was rapid, with a half-life of approximately 2.5 hours. Tablet form II bioavailability (F) relative to capsule was approximately 100% (F = 1.03 [90% confidence interval (CI), 0.96-1.10]). In the second study, participants (n = 27) received semagacestat either fed or fasting in the morning or fasting in the evening. No significant change in exposure (AUC(0-∞) [area under the concentration-time curve from 0 to infinity] ratio = 1.02, [90% CI, 0.990-1.05]) occurred with food, whereas maximum plasma concentration (C(max)) declined approximately 15%, and median t(max) was delayed to 1.5 hours. Time of dosing made no significant difference in AUC(0-∞), C(max), or t(max) (AUC(0-∞) ratio 1.01, [90% CI, 0.975-1.04]). No clinically significant safety concerns occurred in either study. Accordingly, semagacestat may be dosed without regard to formulation, food, or time of administration.
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Affiliation(s)
- Brian A Willis
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA.
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195
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Shoji M. Biomarkers of the dementia. Int J Alzheimers Dis 2011; 2011:564321. [PMID: 21660205 PMCID: PMC3109743 DOI: 10.4061/2011/564321] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/30/2011] [Indexed: 12/12/2022] Open
Abstract
Recent advances in biomarker studies on dementia are summarized here. CSF Aβ40, Aβ42, total tau, and phosphorylated tau are the most sensitive biomarkers for diagnosis of Alzheimer's disease (AD) and prediction of onset of AD from mild cognitive impairment (MCI). Based on this progress, new diagnostic criteria for AD, MCI, and preclinical AD were proposed by National Institute of Aging (NIA) and Alzheimer's Association in August 2010. In these new criteria, progress in biomarker identification and amyloid imaging studies in the past 10 years have added critical information. Huge contributions of basic and clinical studies have established clinical evidence supporting these markers. Based on this progress, essential therapy for cure of AD is urgently expected.
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Affiliation(s)
- Mikio Shoji
- Department of Neurology, Hirosaki University Graduate School of Medicine, 5 Zaifucho, Hirosaki, Aomori 036-8216, Japan
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196
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Cummings JL. Biomarkers in Alzheimer's disease drug development. Alzheimers Dement 2011; 7:e13-44. [PMID: 21550318 DOI: 10.1016/j.jalz.2010.06.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 06/01/2010] [Accepted: 06/03/2010] [Indexed: 12/27/2022]
Abstract
Developing new therapies for Alzheimer's disease (AD) is critically important to avoid the impending public health disaster imposed by this common disorder. Means must be found to prevent, delay the onset, or slow the progression of AD. These goals will be achieved by identifying disease-modifying therapies and testing them in clinical trials. Biomarkers play an increasingly important role in AD drug development. In preclinical testing, they assist in decisions to develop an agent. Biomarkers in phase I provide insights into toxic responses and drug metabolism and in Phase II proof-of-concept trials they facilitate go/no-go decisions and dose finding. Biomarkers can play a role in identifying presymptomatic patients or specific patient subgroups. They can provide evidence of target engagement before clinical changes can be expected. Brain imaging can serve as a primary outcome in Phase II trials and as a key secondary outcome in Phase III trials. Magnetic resonance imaging is currently best positioned for use in large multicenter clinical trials. Cerebrospinal fluid (CSF) measures of amyloid beta protein (Aβ), tau protein, and hyperphosphorylated tau (p-tau) protein are sensitive and specific to the diagnosis of AD and may serve as inclusion criteria and possibly as outcomes in clinical trials targeting relevant pathways. Plasma measures of Aβ are of limited diagnostic value but may provide important information as a measure of treatment response. A wide variety of measures of detectable products of cellular processes are being developed as possible biomarkers accessible in the cerebrospinal fluid and plasma or serum. Surrogate markers that can function as outcomes in pivotal trials and reliably predict clinical outcomes are needed to facilitate primary prevention trials of asymptomatic persons where clinical measures may be of limited value. Fit-for-purpose biomarkers are increasingly available to guide AD drug development decisions.
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Affiliation(s)
- Jeffrey L Cummings
- Cleveland Clinic Lou Ruvo Center for Brain Health, Cleveland Clinic Neurological Institute, Las Vegas, NV, USA.
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197
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Aisen PS. Commentary on “Biomarkers in Alzheimer's disease drug development.” Can't live without 'em. Alzheimers Dement 2011; 7:e48-50. [DOI: 10.1016/j.jalz.2010.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 06/24/2010] [Indexed: 11/24/2022]
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Abstract
Alzheimer's disease (AD) was first described a little more than 100 years ago. It is the most common cause of dementia with an estimated prevalence of 30 million people worldwide, a number that is expected to quadruple in 40 years. There currently is no effective treatment that delays the onset or slows the progression of AD. However, major scientific advances in the areas of genetics, biochemistry, cell biology, and neuroscience over the past 25 years have changed the way we think about AD. This review discusses some of the challenges to translating these basic molecular and cellular discoveries into clinical therapies. Current information suggests that if the disease is detected before the onset of overt symptoms, it is possible that treatments based on knowledge of underlying pathogenesis can and will be effective.
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Affiliation(s)
- David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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199
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Suppression of osteosarcoma cell invasion by chemotherapy is mediated by urokinase plasminogen activator activity via up-regulation of EGR1. PLoS One 2011; 6:e16234. [PMID: 21283769 PMCID: PMC3024416 DOI: 10.1371/journal.pone.0016234] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Accepted: 12/17/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The cellular and molecular mechanisms of tumour response following chemotherapy are largely unknown. We found that low dose anti-tumour agents up-regulate early growth response 1 (EGR1) expression. EGR1 is a member of the immediate-early gene group of transcription factors which modulate transcription of multiple genes involved in cell proliferation, differentiation, and development. It has been reported that EGR1 act as either tumour promoting factor or suppressor. We therefore examined the expression and function of EGR1 in osteosarcoma. METHODS We investigated the expression of EGR1 in human osteosarcoma cell lines and biopsy specimens. We next examined the expression of EGR1 following anti-tumour agents treatment. To examine the function of EGR1 in osteosarcoma, we assessed the tumour growth and invasion in vitro and in vivo. RESULTS Real-time PCR revealed that EGR1 was down-regulated both in osteosarcoma cell lines and osteosarcoma patients' biopsy specimens. In addition, EGR1 was up-regulated both in osteosarcoma patient' specimens and osteosarcoma cell lines following anti-tumour agent treatment. Although forced expression of EGR1 did not prevent osteosarcoma growth, forced expression of EGR1 prevented osteosarcoma cell invasion in vitro. In addition, forced expression of EGR1 promoted down-regulation of urokinase plasminogen activator, urokinase receptor, and urokinase plasminogen activity. Xenograft mice models showed that forced expression of EGR1 prevents osteosarcoma cell migration into blood vessels. CONCLUSIONS These findings suggest that although chemotherapy could not prevent osteosarcoma growth in chemotherapy-resistant patients, it did prevent osteosarcoma cell invasion by down-regulation of urokinase plasminogen activity via up-regulation of EGR1 during chemotherapy periods.
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Pettersson M, Kauffman GW, am Ende CW, Patel NC, Stiff C, Tran TP, Johnson DS. Novel γ-secretase modulators: a review of patents from 2008 to 2010. Expert Opin Ther Pat 2011; 21:205-26. [PMID: 21231889 DOI: 10.1517/13543776.2011.547479] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The amyloid precursor protein is first cleaved by β-secretase to generate a 99-residue membrane-bound CTF (C99 or β-CTF), which is subsequently cleaved by γ-secretase to generate amyloid β (Aβ) peptides and the APP intracellular domain. The amyloidogenic Aβ42 has attracted considerable attention because it is thought to be the most pathogenic species associated with Alzheimer's disease progression. New classes of compounds, called γ-secretase modulators (GSMs), have been shown to selectively lower Aβ42 production without shutting down key γ-secretase-dependent signaling pathways. This has become an important therapeutic strategy aimed at modulating Aβ production. AREAS COVERED The progress on the clinical development of γ-secretase inhibitors is briefly covered in this review, followed by a discussion of the potential differentiating attributes of GSMs. Then, the patent literature covering novel GSMs is reviewed, focusing on patents from 2008 to 2010. EXPERT OPINION Much progress has been made in the past 2 years on developing GSMs with improved potency for lowering the production of Aβ42. However, many of these chemotypes are in a challenging chemical space and generally possess higher lipophilicity than most CNS drugs. It will be important to gain a better understanding of the specific target(s) that these GSMs interact with in order to facilitate future drug design efforts.
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Affiliation(s)
- Martin Pettersson
- Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry, Eastern Point Road, Groton, CT 06340, USA
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