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Clinical Trials of Amyloid-Based Therapies for Alzheimer's Disease

Published online by Cambridge University Press:  07 November 2014

Pierre N. Tariot*
Affiliation:
Dr. Tariot is research professor of psychiatry at the, University of ArizonaCollege of Medicine and director of the Memory Disorders Center at Banner Alzheimer's Institute in Phoenix

Abstract

We appear to be on the brink of a new epoch of treatment for Alzheimer's disease. Compelling evidence suggests that Aβ42 secretion is the triggering event in the pathogenesis of Alzheimer's disease, and that tau aggregation may be an important secondary event linked to neurodegeneration. Prophylactic administration of anti-amyloid agents designed to prevent Aβ accumulation in persons with subclinical disease is likely to be more effective than therapeutic interventions in established Alzheimer's disease. Drug development programs in Alzheimer's disease focus primarily on agents with anti-amyloid disease-modifying properties, and many different pharmacologic approaches to reducing amyloid pathology and tauopathy are being studied. Classes of therapeutic modalities currently in advanced-stage clinical trial testing include forms of immunotherapy (activeβ-amyloid immunoconjugate and human intravenous immunoglobulin), a γ-secretase inhibitor, the selective Aβ42-lowering agent R-flurbiprofen, and the anti-aggregation agent tramiprosate. Non-traditional dementia therapies such as the HMG-CoA reductase inhibitors (statins), valproate, and lithium are now being assessed for clinical benefit as anti-amyloid disease-modifying treatments. Positive findings of efficacy and safety from clinical studies are necessary but not sufficient to demonstrate that a drug has disease-modifying properties. Definitive proof of disease-modification requires evidence from validated animal models of Alzheimer's disease; rigorously controlled clinical trials showing a significantly improved, stabilized, or slowed rate of decline in cognitive and global function compared to placebo; and prospectively obtained evidence from surrogate biomarkers that the treatment resulted in measurable biological changes associated with the underlying disease process.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2007

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References

1.Gelinas, DS, DaSilva, K, Fenili, D Stet al.Immunotherapy for Alzheimer's disease. PNAS. 2004;101(suppl 2):1465714662.CrossRefGoogle ScholarPubMed
2.Walker, LC, Ibegbu, CC, Todd, CW, et al.Emerging prospects for the disease-modifying treatment of Alzheimer's disease. Biochem Pharmacol. 2005;69:10011008.CrossRefGoogle ScholarPubMed
3.Schenk, D, Barbour, R, Dunn, W, et al.Immunization with amyloid-β attenuates Alzheimer-disease-like pathology in the PDAPP mouse. Nature. 1999;400:173177.CrossRefGoogle ScholarPubMed
4.Gilman, S, Koller, M, Black, RS, et al for the AN1792(QS-21)-201 Study Team. Clinical effects of Aβ immunization (AN1792) in patients with AD in an interrupted trial. Neurology. 2005;64:15531562.CrossRefGoogle Scholar
5.Nicoll, JA, Wilkinson, D, Holmes, C, et al.Neuropathology of human Alzheimer disease after immunization with amyloid-beta peptide: a case report. Nat Med. 2003;9:448452.CrossRefGoogle ScholarPubMed
6.Orgogoza, JM. Vaccination treatment of AD (abstract S5-04-04). Alzheimer's & Dementia. 2006;2:S94.Google Scholar
7.Fox, NC, Black, RS, Gilman, S, et al for the AN1792 (QS-21)-201 Study Team. Effects of A-beta immunotherapy (AN1792) on MRI measures of cerebral volume in Alzheimer disease. Neurology. 2005;64:15631572.CrossRefGoogle Scholar
8.Bales, KR, Tzavara, ET, Wu, S, et al.Cholinergic dysfunction in a mouse model of Alzheimer disease is reversed by an anti-Aβ antibody. J Clin Invest. 2006;116:825832.CrossRefGoogle Scholar
9.Dodel, RC, Du, Y, Depboylu, C, et al.Intravenous immunoglobulins containing antibodies against β-amyloid for the treatment of Alzheimer's disease. Br Med J. 2004;75:14721474.Google ScholarPubMed
10.Relkin, N, Szabo, P, Adamiak, B, et al.Intravenous immunoglobulin (IVIg) treatment causes dose-dependent alterations in β-Amyloid (Aβ) levels and anti-Aβ antibody titers in plasma and cerebrospinal fluid (csf) of Alzheimer's Disease (AD) patients. Neurology. 2005;64(supplement 1):A144.Google Scholar
11.Pollack, SJ, Lewis, H. Secretase inhibitors for Alzheimer's disease: challenges of a promiscuous protease. Curr Opin Investig Drugs. 2005;6:3547.Google ScholarPubMed
12.Wong, GT, Manfra, D, Poulet, FM, et al.Chronic treatment with the β-secretase inhibitor LY-411,575 inhibits β-amyloid peptide production and alters lymphopoiesis and intestinal cell differentiation. J Biol Chem. 2004;279:1287612882.CrossRefGoogle ScholarPubMed
13.Citron, M. Strategies for disease modification in Alzheimer's disease. Nat Rev Neurosci. 2004;5:677685.CrossRefGoogle ScholarPubMed
14.Rosenberg, RN. Explaining the cause of the amyloid burden in Alzheimer disease. Arch Neurol. 2005;59:13671368.CrossRefGoogle Scholar
15.Siemers, E, Skinner, M, Dean, RA, et al.Safety, tolerability, and changes in amyloid β concentrations after administration of a β-secretase inhibitor in volunteers. Clin Neuropharmacol. 2005;28:126132.CrossRefGoogle ScholarPubMed
16.Siemers, ER, Quinn, JF, Kaye, J, et al.Effects of a gamma-secretase inhibitor in a randomized study of patients with Alzheimer disease. Neurology. 2006;66:602604.CrossRefGoogle Scholar
17.Beher, D, Clarke, EE, Wrigley, JD, et al.Selected non-steroidal anti-inflammatory drugs and their derivatives target β-secretase at a novel site. Evidence for an allosteric mechanism. J Biol Chem. 2004;279:4341943426.CrossRefGoogle Scholar
18.Weggen, S, Eriksen, JL, Sagi, SA, et al.Evidence that nonsteroidal anti-inflammatory drugs decrease amyloid β42 production by direct modulation of b-secretase activity. J Biol Chem. 2003;278:3183131837.CrossRefGoogle Scholar
19.Townsend, KP, Praticò, D. Novel therapeutic opportunities for Alzheimer's disease: focus on nonsteroidal anti-inflammatory drugs. FASEB J. 2005;19:15921601.CrossRefGoogle ScholarPubMed
20.Golde, TE, Eriksen, J, Nicolle, M, et al.Selective Abeta42 modifying agents: effects on Abeta deposition and behavior in Tg2576 mice. Presented at: The 9th International Conference on Alzheimer's Disease and Related Disorders; Philadelphia, PA; July 18, 2004.Google Scholar
21.Galasko, D, Graff-Radford, N, Murphy, MP, et al.Safety, tolerability, pharmacokinetics and Ab levels following short-term administration of R-flurbiprofen in healthy elderly individuals: a Phase I study. Presented at: The 9th International Conference on Alzheimer's Disease and Related Disorders; Philadelphia, PA; July 18, 2004.Google Scholar
22.Wilcock, GK, Black, SE, Haworth, J, et al.Efficacy and safety of MPC-7969 (R-flurbiprofen), a selective Aβ42-lowering agent, in Alzheimer's disease (AD): results of a 12-month phase 2 trial and 1-year follow-on study (abstract 04-03-08). Alzheimer's & Dementia. 2006;2(Suppl 1):S81.CrossRefGoogle Scholar
23.Gervais, F, Chalifour, R, Garceau, D, et al.Glycosaminoglycan mimetics: a therapeutic approach to cerebral amyloid angiopathy. Amyloid. 2001;8(suppl 1):2835Google ScholarPubMed
24.Garceau, D, Gurbindo, C, Laurin, J. Safety, tolerability and pharmacokinetic profile of Alzhemedβ, an anti-amyloid agent for Alzheimer's disease, in healthy subjects. Presented at: The 7th International Geneva/Springfield Symposium on Advances in Alzheimer Therapy; Geneva, Switzerland; April 3-6, 2002.Google Scholar
25.Geerts, H. NC-531 Neurochem. Curr Opin Investig Drugs. 2004;5:95100.Google ScholarPubMed
26.Aisen, P, Mehran, M, Poole, R, et al.Clinical data on Alzhemed after 12 months of treatment in patients with mild to moderate Alzheimer's disease. Presented at the 9th International Conference on Alzheimer's Disease and Related Disorders. Philadelphia, PA; July, 2004.Google Scholar
27.Rosenberg, RN. Metal chelation therapy for Alzheimer disease. Arch Neurol. 2003;60:16781679.CrossRefGoogle ScholarPubMed
28.Treiber, C, Simons, A, Strauss, M, et al.Clioquinol mediates copper uptake and counteracts copper efflux activities of the amyloid precursor protein of Alzheimer's disease. J Biol Chem. 2004;279:5195851964.CrossRefGoogle ScholarPubMed
29.Ritchie, CW, Bush, AI, Mackinnon, A, et al.Metal-protein attenuation with iodochlorhydroxyquin (Clioquinol) targeting Aβ amyloid deposition and toxicity in Alzheimer disease. Arch Neurol. 2003;60:16851691.CrossRefGoogle ScholarPubMed
30.Gibson, GL, Douraghi-Zadeh, D, Parsons, RB, Austen, BM. Properties of ovine colostrinin (O-CLN) on the in vitro aggregation and toxicity of β-amyloid. Neurobiol Aging. 2004;25:592.CrossRefGoogle Scholar
31.Rattray, M. Technology evaluation: Colostrinin, ReGen. Curr Opin Molecular Therap. 2005;7:7884.Google ScholarPubMed
32.Bilikiewicz, A, Gaus, W. Colostrinin (a naturally occurring, proline-rich, polypeptide mixture) in the treatment of Alzheimer's disease. J Alzheimer's Dis. 2004;6:1726.CrossRefGoogle ScholarPubMed
33.Leszek, J, Inglot, AD, Janusz, M, et al.Colostrinin proline-rich polypeptide complex from ovine colostrum-a long-term study of its efficacy in Alzheimer's disease. Med Sci Monit. 2002;8:193196.Google ScholarPubMed
34.Jick, H, Zornberg, GL, Jick, SS, Seshadri, S, Drachman, DA. Statins and the risk of dementia. Lancet. 2000;356:16271631.CrossRefGoogle ScholarPubMed
35.Wolozin, B, Kellman, W, Ruosseau, P, Celesia, GG, Siegel, G. Decreased prevalence of Alzheimer disease associated with 3-hydroxy-3methyglutaryl coenzyme A reductase inhibitors. Arch Neurol. 2000;57:14391443.CrossRefGoogle Scholar
36.Pedrini, S, Carter, TL, Prendergast, G, Petanceska, S, Ehrlich, ME, Gandy, S. Modulation of statin-activated shedding of Alzheimer APP ectodomain by ROCK. PLoS Med. 2005;2:e18. Epub 2005 Jan 11.CrossRefGoogle ScholarPubMed
37.Simons, M, Schwarzler, F, Lutjohann, D, et al.Treatment with simvastatin in normocholesterolemic patients with Alzheimer's disease: a 26-week randomized, placebo-controlled, double-blind trial. Ann Neurol. 2002;52:346350.CrossRefGoogle ScholarPubMed
38.Sparks, DL, Sabbagh, MN, Connor, DJ, et al.Atorvastatin for the treatment of mild to moderate Alzheimer's disease. Arch Neurol. 2005;62:753757.CrossRefGoogle Scholar
39.Atamna, H, Boyle, K. Amyloid-b peptide binds with heme to form a peroxidase: relationship to the cytopathologies of Alzheimer's disease. PNAS. 2006;103:33813386.CrossRefGoogle Scholar
40.Ono, K, Yamada, M. Antioxidant compounds have potent anti-fibrillogenic and fibril-destabilizing effects for alpha-synuclein fibrils in vitro. J Neurochem. 2006;97:105115.CrossRefGoogle ScholarPubMed
41.Tariot, PN, Loy, R, Ryan, JM, Porsteinsson, A, Ismail, S. Mood stabilizers in Alzheimer's disease: symptomatic and neuroprotective rationales. Adv Drug Deliv Rev. 2002;54:15671577.CrossRefGoogle ScholarPubMed
42.Kim, AJ, Shi, Y, Austin, RC, Werstuck, GH. Valproate protects cells from ER stress-induced lipid accumulation and apoptosis by inhibiting glycogen synthase kinase-3. J Cell Sci. 2005;118:8999.CrossRefGoogle ScholarPubMed
43.Su, Y, Ryder, J, Li, B, et al.Lithium, a common drug for bipolar disorder treatment, regulates amyloid-beta precursor protein processing. Biochemistry. 2004;43:68996908.CrossRefGoogle ScholarPubMed
44.Noble, W, Planel, E, Zehr, C, et al.Inhibition of glycogen synthase kinase-3 by lithium correlates with reduced tauopathy and degeneration in vivo. PNAS. 2005;102:69906995.CrossRefGoogle ScholarPubMed
45.Gomez-Ramos, A, Dominguez, J, Zafra, D, et al.Inhibition of GSK3 dependent tau phosphorylation by metals. Curr Alzheimer Res. 2006;3:123127.CrossRefGoogle ScholarPubMed
46.Annas, P. A randomised, single-blind, placebo-controlled, multicentre study to investigate the pharmacodynamic effects of lithium on GSK-3 activity in patients with mild Alzheimer's disease (abstract P2-082). Alzheimer's & Dementia. 2006;2:S257.CrossRefGoogle Scholar