- Email: [email protected]
Pharmacokinetic and pharmacodynamic evaluation of orally available hydroxyethylamine-derived beta-secretase inhibitors in Sprague Dawley rats
Poster Presentations: P1 mg avagacestat. In the second study, 8 mg galantamine was administered daily for 7 days, then 16 mg daily for 7 days, followed by a co-administration period of 10 days with 125 mg avagacestat. Results: 32 and 34 subjects were randomized in the donepezil and galantamine study, respectively. Coadministration of avagacestat and donepezil or galantamine was associated with an increase in the geometric mean Cmax (14-21%) and AUC(TAU) (24-26%) of donepezil and/or galantamine; an increase not likely to be clinically relevant. One serious adverse event (SAE) was reported in healthy subjects co-administered avagacestat and galantamine for 10 days. On Day 25, a subject was found to have elevated lipase (5x ULN) and amylase (2x ULN) and was diagnosed with pancreatitis. The subject, who also had multiple gall stones, was admitted to the hospital, was treated, and recovered fully. Co-administration of avagacestat with either donepezil or galantamine in healthy subjects for short periods of time was associated with a higher frequency of AEs than administration of donepezil or galantamine alone. The most common AEs in either study included headache, nausea, and epistaxis. Most AEs were mild in nature and all, except nasal congestion, resolved prior to study discharge. Conclusions: Co-administration of multiple 125 mg doses of avagacestat (the highest dose tested in phase IIb studies) and either donepezil or galantamine at steady-state appeared to be generally well tolerated in healthy subjects. Co-administration of avagacestat was not associated with clinically relevant increases in Cmax or AUC for either donepezil or galantamine.
P1-241
IN VIVO REDUCTION OF BETA-AMYLOID PEPTIDES IN THE BRAIN OF TG2576 MICE AFTER ORAL ADMINISTRATION OF A NOVEL BACE1 INHIBITOR
Susanna Eketj€ all1, Juliette Jansson1, Kristina Eliason1, Paulina Appelkvist1, Ann-Cathrin Rades€ater1, Fredrik Jeppsson1, Susanne Gustavsson1, Sofia Karlstr€om1, Karin Kolmodin1, Samuel Svensson2, Johanna F€alting1, 1Innovative Medicines CNSP, S€ odert€ alje, Sweden; 2iMED Neuroscience AstraZeneca R&D, S€odert€alje, Sweden. Background: The transmembrane aspartic acid protease BACE1 cleaves amyloid precursor protein (APP) to generate Ab, inhibition of BACE1 is therefore a favorable approach for therapeutic intervention in Alzheimer’s disease (AD). Small molecule BACE1 inhibitors are expected to decrease Aß-peptide generation and thereby reduce amyloid plaque formation in the brain, a hallmark neuropathological lesion in AD. Tg2576, a mouse model overexpressing human APP with the Swedish mutation, is a widely used animal model to study amyloidosis. Aim: In the present study, the pharmacokinetic and pharmacodynamic (PK/PD) properties of a novel small molecule BACE1 inhibitor (AZ-17) was evaluated in vivo using C57BL/6 and Tg2576 mice. Methods: The in vitro potency for AZ-17 was first evaluated using primary cortical neuron from C57BL/6 or Tg2576 mice. C57BL/6 mice were then used to study the dose- and time-dependent reduction of Ab after a single oral dose of AZ-17. The effect of AZ-17 on amyloid deposition was studied in 11 month old female Tg2567 mice, which received AZ-17 once daily for 28 days. Results: AZ-17 displayed a potency difference in vitro between C57BL/6 and Tg2576 primary cortical neurons. In C57BL/6 mice AZ-17 demonstrated a dose- and time-depended reduction of brain Ab. The insoluble pool of Ab was reduced in Tg2576 after 28 days treatment with AZ-17. Conclusions: These results demonstrate that an oral small molecule BACE1 inhibitor reduces the levels of both soluble and insoluble Aß in the brain, thereby supporting BACE1 inhibition as a feasible approach for disease modification in AD.
P1-242
REACTIVITY OF HUMAN NATURAL ANTIBODIES TO VARIOUS Ab PEPTIDES
Seungwoo Kim, Young-Youl Kim, Division of Brain Disease, KNIH, Chungbuk, South Korea.
P191
Background: Accumulation of the Ab peptide plays a crucial role in the pathogenesis of Alzheimer’s disease (AD). Many treatments for AD, delay the accumulation of Ab, but evidence for reduced pre-existing plaques is unknown. Immunotherapy for AD, using human natural Ab antibodies are currently in development. Anti-Ab antibodies occur naturally in human blood and CSF in free or complex form with Ab. Antibody reactivity was known prominent against oligomeric assemblies of Ab and pyroglutamte or oxidized residues. But their diversity, abundance, and function remain largely unknown and large-scale analysis of Ab antibody changes has not been described. Methods: Here, we demonstrated changes of natural Ab antibody reactivity in human serum sample with peptide microarrays between healthy control (n ¼ 100) and mild cognitive impairment (MCI, n ¼ 100) and AD patients (n ¼ 100), against various Ab peptide. Results: Some of Ab peptides show increasing reactivity in AD patients serum compared with healthy control. Interestingly, N-terminal truncated pyroglutamte Ab peptide, Ab 22(pE)-42 immunoreactivity significantly (p < 0.001) increased in MCI and AD patients serum compared healthy control. Ab 22(pE)-42 reduced cell viability in human neuroblastoma cell and aggregated in vitro. After active immunization with mice, antibody titration to Ab 22(pE)-42 were increased but T-cell activation were not changed. Conclusions: These results suggest that Ab22(pE)-42 may be helpful in better immunotherapy target of AD.
P1-243
PHARMACOKINETIC AND PHARMACODYNAMIC EVALUATION OF ORALLY AVAILABLE HYDROXYETHYLAMINE-DERIVED BETA-SECRETASE INHIBITORS IN SPRAGUE DAWLEY RATS
Stephen Wood1, Paul Wen1, Patricia Amarante1, Paul Acton1, Jodi Bradley1, Safura Babu-Khan1, Kui Chen1, Jan Zhang1, Li Zhu1, Yuan Cheng1, Tom Dineen2, Joel Esmay1, Russell Graceffa2, Daniel Horne1, Hongbing Huang2, Ted Judd1, Mathew Kaller1, Patricia Lopez1, Yi Luo1, Steven Louie1, Robert Wahl1, Matt Weiss2, Bryant Yang1, Wenge Zhong1, Dean Hickman1, Toni Williamson1, 1Amgen, Thousand Oaks, California, United States; 2Amgen, Cambridge, Massachusetts, United States. Background: Alzheimer’s Disease (AD), a progressive neurodegenerative disorder, is the most common form of dementia affecting 4-8% of the elderly population worldwide. Aggregation of the core constituent of amyloid plaques, Aß is believed to play a critical role in the pathology of AD. The aspartyl protease, beta-site amyloid precursor protein cleaving enzyme (BACE1), catalyses the rate-limiting step in the production of Ab and is therefore considered to be an important target for drug development in AD. Methods: In vitro potency: Enzyme IC 50s were measured using recombinant BACE1 and a FRET-labeled peptide substrate. Cellbased IC 50s were generated using HEK293 cells stably transfected with APPSw. In vitro pharmacokinetics: Passive permeability and P-gp-dependent efflux ratios were evaluated using LLC-PK1 cell monolayers. Microsomal stability was assessed by HPLC following incubation of compounds with rat liver microsomes. In vivo PK/PD: BACE1 inhibitors were administered in a single oral dose to male Sprague-Dawley rats. At various time points, plasma, CSF, and brain were sampled for Ab and compound measurement. Results: Using a rational drug design approach we have designed and developed a new series of hydroxyethylamine (HEA)based inhibitors of BACE1. Dose dependent lowering of Aß levels in the brain and cerebrospinal fluid (CSF) of rats following oral administration was demonstrated. Global assessment of 104 compounds in this series revealed strong inverse relationships between P-gp efflux and CSF and brain Ab40 inhibition and between passive permeability and Aß inhibition. A positive correlation was observed between microsomal stability and central Aß inhibition. Conclusions: Here we describe a new series of hydroxyethylamine (HEA)-based inhibitors of BACE1 capable of lowering Aß levels in brain and CSF of rats following oral administration. Further, we describe
P192
Poster Presentations: P1
the relationship between P-gp efflux, microsomal stability and passive permeability and in vivo pharmacodynamics in a large set of compounds with comparable in vitro potency.
P1-244
ANTISENSE TARGETING Aß PRECURSOR PROTEIN IMPROVES LEARNING AND MEMORY IN APPSWE MICE
Susan Farr1, Michelle Erickson2, William Banks3, John Morley4, 1St. Louis University/VA Medical Center St. Louis, St Louis, Missouri, United States; 2 St. Louis University, St. Louis, Missouri, United States; 3University of Washington/VA Pudget Sound, Seattle, Washington, United States; 4St. Louis University Medical Center, St. Louis, Missouri, United States. Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder of the central nervous system (CNS). Learning and memory deficits are the hallmark of Alzheimer’s disease. Studies have revealed that beta-amyloid (Ab) plays a key role in these deficits. Elevated brain levels of Ab lead oxidative damage in the brain resulting in learning and memory deficits. We have previously shown that an amyloid precursor protein (APP) antisense oligonucleotide reverses age-related changes in the SAMP8 mouse, which has a natural mutation that produces an age-related impairment in learning and memory that is driven by an age-related increase in brain levels of Ab. Methods: Here, we tested OL-1 in APPswe mice model of Alzheimer’s disease using both peripheral and central injections. APPswe mice were tested in object recognition with a 24 hour delay after tail vein injection. We also tested our OL-1 in the APPswe that overexpress the human APP gene and have an age-related impairment in learning and memory, elevated brain levels of Ab, and increased oxidative damage in the hippocampus. We administered mOL-1, intracerebroventricularly (ICV) or tail vein (TV) to 13 month old APPswe mice. We tested the mince in T-maze foot shock avoidance. Results: The APPswe mice treated centrally with OL-1 took 9.00 6 0.72 trials to make an avoidance whereas the APPswe mice treated with random antisense took 14.50 6 1.73. The age-matched wild type controls took 10.09 6 0.66. On the one week retention test the OL-1 treated APPswe mice took 8.73 6 0.63 to reach criterion of 5 avoidances in 6 consecutive trials, the APPswe mice that received random antisense took 16.20 6 2.58 and the wild type controls took 9.00 6 0.58 trials to reach criterion. APPswe mice treated peripherally with OL-1 showed improved learning and memory in T-maze foot shock avoidance and object recognition. APP expression was decreased by 20% in the APPswe mice treated with OL-1. HNE was decreased in the brain tissue. Conclusions: The current findings indicate that antisense oligonucleotide administered both centrally and peripherally can reverse learning and memory impairment produced by Ab the APPswe transgenic mice, which overexpress human beta-amyloid.
P1-245
INTRAVENOUS IMMUNOGLOBULIN CONTAINS POLYCLONAL Aß-SPECIFIC ANTIBODIES THAT MODIFY Aß AGGREGATION, NEUROTOXICITY AND PHAGOCYTOSIS IN VITRO
Susann Cattepoel1, Alexander Schaub1, Annette Gaida1, Ursula Guggisberg1, Marc W. Nolte2, Reinhard Bolli1, Louis Fabri3, Sylvia Miescher1, 1CSL Behring AG, Bern, Switzerland; 2CSL Behring GmbH, Marburg, Germany; 3CSL Ltd., Parkville, Australia. Background: Intravenous Immunoglobulin (IVIG) has been proposed as a potential therapeutic for Alzheimer’s disease (AD) and its efficacy is currently being tested in mild-to-moderate AD. Earlier studies reported reduced levels of serum anti-Ab antibodies in AD patients and the presence of these antibodies in IVIG. These observations led to clinical studies investigating the potential role of IVIG as a therapeutic agent in AD. In this study we wanted to investigate the potential of polyclonal Ab -specific antibodies (pAbs-Ab) present in IVIG preparations to modulate Ab aggregation, Ab-
mediated neurotoxicity and phagocytosis of fibrillar A b by BV-2 microglia in vitro. Methods: The pAbs-A b were purified from PrivigenÒ by Affinity Chromatography and their potential to inhibit Ab aggregation in a Thioflavin T fluorescence assay has been evaluated. Furthermore, the effect of pAbsAb on Ab-induced toxicity to SH-SY5Y cells and primary rat cortical neurons, as well as phagocytosis of fibrillar Ab by BV-2 mouse microglia was investigated. Results: In this study we show that approximately 0.1% pAbsAb are present in PrivigenÒ. These antibodies specifically bound to A b, inhibited its aggregation in Thioflavin T assay and appeared to prevent Ab-binding to neurons as visualized by confocal microscopy. Interestingly, not pAbs-Ab, but only the full IVIG preparation increased microglial phagocytosis of fibrillar Ab. Conclusions: Our results suggest that the b specific antibodies in PrivigenÒ may have an impact on Ab -driven processes in the pathogenesis of AD. In addition to the effects mediated by those antibodies, the established anti-inflammatory and immune-modulating properties of IVIG might further add to the beneficial effects observed in clinical studies.
P1-246
N-HETEROARYL-PIPERIDINYL-4-AMINES AS SELECTIVE GAMMA SECRETASE MODULATORS FOR THE POTENTIAL TREATMENT OF ALZHEIMER’S DISEASE
Thomas Luebbers, Anja Limberg, Synese Jolidon, Erwin Goetschi, Helmut Jacobsen, Luke Green, Alexander Flohr, Andrew Thomas, Henner Knust, Pascale David-Pierson, Karlheinz Baumann, F. Hoffmann-La Roche Ltd, Basel, Switzerland. Background: Alzheimer’s disease (AD) is the most common dementia in elderly. It is characterized by progressive memory loss accompanied by declining activities of daily living and neuropsychiatric symptoms and behavioral changes. In the brains of AD patients extracellular senile plaques composed of Aß peptides, intracellular neurofibrillary tangles consisting mainly of hyperphosphorylated tau and prominent neuronal loss are observed. Inhibition of g -secretase, the Aß-producing enzyme, is therapeutically unfavorable since it leads to Notch-related (another substrate of g -sercetase) toxicity in the thymus, gut and spleen. g -secretase modulators do not inhibit the enzyme but shift the formation of the toxic Aß42 peptide mainly to the formation of non-toxic Aß38 peptide without interfering with the processing of Notch. Methods: In the course of the optimization of the g -secretase modulators we tested the compounds in vitro in H4 cells overexpressing Aß42 and in vivo in an APP-transgenic mouse model as well as in nontransgenic rats for specific reduction of A b 42 in brain or CSF. Results: Starting from a previously reported g -secretase modulator 1 with an aminopyrimidine core we exchanged the central core by an aminotriazolopyridine core leading to highly potent compound 2 in vitro (IC 50 ¼ 92 nM). Replacement of the typical aromatic headgroup by a novel saturated aminopiperidine headgroup led to compound 3 with improved physicochemical properties and excellent brain activity in the transgenic mouse model as well as significant reduction of Aß42 in CSF of non-transgenic rats. Conclusions: A novel headgroup for g -secretase modulators was designed which provided compounds with excellent in vivo activity. We will describe detailed SAR and molecular properties for key compounds in this novel class.
P1-247
BETA-AMYLOID AGGREGATION HUMAN SYSTEMS PHARMACOLOGY MODELING: DEVELOPMENT AND APPLICATION TO PHARMACOLOGICAL TARGETS IN ALZHEIMER’S DISEASE
Timothy Nicholas1, Hugh Barton1, Yasong Lu1, Sridhar Duvvuri1, Tatiana Karelina2, Oleg Demin2, Kirill Zhudenkov2, Sergey Belykh2, Oleg Demin, Jr,2, 1Pfizer, Groton, Connecticut, United States; 2Institute for Systems Biology SPb, Moscow, Russia.
P1-241
IN VIVO REDUCTION OF BETA-AMYLOID PEPTIDES IN THE BRAIN OF TG2576 MICE AFTER ORAL ADMINISTRATION OF A NOVEL BACE1 INHIBITOR
Susanna Eketj€ all1, Juliette Jansson1, Kristina Eliason1, Paulina Appelkvist1, Ann-Cathrin Rades€ater1, Fredrik Jeppsson1, Susanne Gustavsson1, Sofia Karlstr€om1, Karin Kolmodin1, Samuel Svensson2, Johanna F€alting1, 1Innovative Medicines CNSP, S€ odert€ alje, Sweden; 2iMED Neuroscience AstraZeneca R&D, S€odert€alje, Sweden. Background: The transmembrane aspartic acid protease BACE1 cleaves amyloid precursor protein (APP) to generate Ab, inhibition of BACE1 is therefore a favorable approach for therapeutic intervention in Alzheimer’s disease (AD). Small molecule BACE1 inhibitors are expected to decrease Aß-peptide generation and thereby reduce amyloid plaque formation in the brain, a hallmark neuropathological lesion in AD. Tg2576, a mouse model overexpressing human APP with the Swedish mutation, is a widely used animal model to study amyloidosis. Aim: In the present study, the pharmacokinetic and pharmacodynamic (PK/PD) properties of a novel small molecule BACE1 inhibitor (AZ-17) was evaluated in vivo using C57BL/6 and Tg2576 mice. Methods: The in vitro potency for AZ-17 was first evaluated using primary cortical neuron from C57BL/6 or Tg2576 mice. C57BL/6 mice were then used to study the dose- and time-dependent reduction of Ab after a single oral dose of AZ-17. The effect of AZ-17 on amyloid deposition was studied in 11 month old female Tg2567 mice, which received AZ-17 once daily for 28 days. Results: AZ-17 displayed a potency difference in vitro between C57BL/6 and Tg2576 primary cortical neurons. In C57BL/6 mice AZ-17 demonstrated a dose- and time-depended reduction of brain Ab. The insoluble pool of Ab was reduced in Tg2576 after 28 days treatment with AZ-17. Conclusions: These results demonstrate that an oral small molecule BACE1 inhibitor reduces the levels of both soluble and insoluble Aß in the brain, thereby supporting BACE1 inhibition as a feasible approach for disease modification in AD.
P1-242
REACTIVITY OF HUMAN NATURAL ANTIBODIES TO VARIOUS Ab PEPTIDES
Seungwoo Kim, Young-Youl Kim, Division of Brain Disease, KNIH, Chungbuk, South Korea.
P191
Background: Accumulation of the Ab peptide plays a crucial role in the pathogenesis of Alzheimer’s disease (AD). Many treatments for AD, delay the accumulation of Ab, but evidence for reduced pre-existing plaques is unknown. Immunotherapy for AD, using human natural Ab antibodies are currently in development. Anti-Ab antibodies occur naturally in human blood and CSF in free or complex form with Ab. Antibody reactivity was known prominent against oligomeric assemblies of Ab and pyroglutamte or oxidized residues. But their diversity, abundance, and function remain largely unknown and large-scale analysis of Ab antibody changes has not been described. Methods: Here, we demonstrated changes of natural Ab antibody reactivity in human serum sample with peptide microarrays between healthy control (n ¼ 100) and mild cognitive impairment (MCI, n ¼ 100) and AD patients (n ¼ 100), against various Ab peptide. Results: Some of Ab peptides show increasing reactivity in AD patients serum compared with healthy control. Interestingly, N-terminal truncated pyroglutamte Ab peptide, Ab 22(pE)-42 immunoreactivity significantly (p < 0.001) increased in MCI and AD patients serum compared healthy control. Ab 22(pE)-42 reduced cell viability in human neuroblastoma cell and aggregated in vitro. After active immunization with mice, antibody titration to Ab 22(pE)-42 were increased but T-cell activation were not changed. Conclusions: These results suggest that Ab22(pE)-42 may be helpful in better immunotherapy target of AD.
P1-243
PHARMACOKINETIC AND PHARMACODYNAMIC EVALUATION OF ORALLY AVAILABLE HYDROXYETHYLAMINE-DERIVED BETA-SECRETASE INHIBITORS IN SPRAGUE DAWLEY RATS
Stephen Wood1, Paul Wen1, Patricia Amarante1, Paul Acton1, Jodi Bradley1, Safura Babu-Khan1, Kui Chen1, Jan Zhang1, Li Zhu1, Yuan Cheng1, Tom Dineen2, Joel Esmay1, Russell Graceffa2, Daniel Horne1, Hongbing Huang2, Ted Judd1, Mathew Kaller1, Patricia Lopez1, Yi Luo1, Steven Louie1, Robert Wahl1, Matt Weiss2, Bryant Yang1, Wenge Zhong1, Dean Hickman1, Toni Williamson1, 1Amgen, Thousand Oaks, California, United States; 2Amgen, Cambridge, Massachusetts, United States. Background: Alzheimer’s Disease (AD), a progressive neurodegenerative disorder, is the most common form of dementia affecting 4-8% of the elderly population worldwide. Aggregation of the core constituent of amyloid plaques, Aß is believed to play a critical role in the pathology of AD. The aspartyl protease, beta-site amyloid precursor protein cleaving enzyme (BACE1), catalyses the rate-limiting step in the production of Ab and is therefore considered to be an important target for drug development in AD. Methods: In vitro potency: Enzyme IC 50s were measured using recombinant BACE1 and a FRET-labeled peptide substrate. Cellbased IC 50s were generated using HEK293 cells stably transfected with APPSw. In vitro pharmacokinetics: Passive permeability and P-gp-dependent efflux ratios were evaluated using LLC-PK1 cell monolayers. Microsomal stability was assessed by HPLC following incubation of compounds with rat liver microsomes. In vivo PK/PD: BACE1 inhibitors were administered in a single oral dose to male Sprague-Dawley rats. At various time points, plasma, CSF, and brain were sampled for Ab and compound measurement. Results: Using a rational drug design approach we have designed and developed a new series of hydroxyethylamine (HEA)based inhibitors of BACE1. Dose dependent lowering of Aß levels in the brain and cerebrospinal fluid (CSF) of rats following oral administration was demonstrated. Global assessment of 104 compounds in this series revealed strong inverse relationships between P-gp efflux and CSF and brain Ab40 inhibition and between passive permeability and Aß inhibition. A positive correlation was observed between microsomal stability and central Aß inhibition. Conclusions: Here we describe a new series of hydroxyethylamine (HEA)-based inhibitors of BACE1 capable of lowering Aß levels in brain and CSF of rats following oral administration. Further, we describe
P192
Poster Presentations: P1
the relationship between P-gp efflux, microsomal stability and passive permeability and in vivo pharmacodynamics in a large set of compounds with comparable in vitro potency.
P1-244
ANTISENSE TARGETING Aß PRECURSOR PROTEIN IMPROVES LEARNING AND MEMORY IN APPSWE MICE
Susan Farr1, Michelle Erickson2, William Banks3, John Morley4, 1St. Louis University/VA Medical Center St. Louis, St Louis, Missouri, United States; 2 St. Louis University, St. Louis, Missouri, United States; 3University of Washington/VA Pudget Sound, Seattle, Washington, United States; 4St. Louis University Medical Center, St. Louis, Missouri, United States. Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder of the central nervous system (CNS). Learning and memory deficits are the hallmark of Alzheimer’s disease. Studies have revealed that beta-amyloid (Ab) plays a key role in these deficits. Elevated brain levels of Ab lead oxidative damage in the brain resulting in learning and memory deficits. We have previously shown that an amyloid precursor protein (APP) antisense oligonucleotide reverses age-related changes in the SAMP8 mouse, which has a natural mutation that produces an age-related impairment in learning and memory that is driven by an age-related increase in brain levels of Ab. Methods: Here, we tested OL-1 in APPswe mice model of Alzheimer’s disease using both peripheral and central injections. APPswe mice were tested in object recognition with a 24 hour delay after tail vein injection. We also tested our OL-1 in the APPswe that overexpress the human APP gene and have an age-related impairment in learning and memory, elevated brain levels of Ab, and increased oxidative damage in the hippocampus. We administered mOL-1, intracerebroventricularly (ICV) or tail vein (TV) to 13 month old APPswe mice. We tested the mince in T-maze foot shock avoidance. Results: The APPswe mice treated centrally with OL-1 took 9.00 6 0.72 trials to make an avoidance whereas the APPswe mice treated with random antisense took 14.50 6 1.73. The age-matched wild type controls took 10.09 6 0.66. On the one week retention test the OL-1 treated APPswe mice took 8.73 6 0.63 to reach criterion of 5 avoidances in 6 consecutive trials, the APPswe mice that received random antisense took 16.20 6 2.58 and the wild type controls took 9.00 6 0.58 trials to reach criterion. APPswe mice treated peripherally with OL-1 showed improved learning and memory in T-maze foot shock avoidance and object recognition. APP expression was decreased by 20% in the APPswe mice treated with OL-1. HNE was decreased in the brain tissue. Conclusions: The current findings indicate that antisense oligonucleotide administered both centrally and peripherally can reverse learning and memory impairment produced by Ab the APPswe transgenic mice, which overexpress human beta-amyloid.
P1-245
INTRAVENOUS IMMUNOGLOBULIN CONTAINS POLYCLONAL Aß-SPECIFIC ANTIBODIES THAT MODIFY Aß AGGREGATION, NEUROTOXICITY AND PHAGOCYTOSIS IN VITRO
Susann Cattepoel1, Alexander Schaub1, Annette Gaida1, Ursula Guggisberg1, Marc W. Nolte2, Reinhard Bolli1, Louis Fabri3, Sylvia Miescher1, 1CSL Behring AG, Bern, Switzerland; 2CSL Behring GmbH, Marburg, Germany; 3CSL Ltd., Parkville, Australia. Background: Intravenous Immunoglobulin (IVIG) has been proposed as a potential therapeutic for Alzheimer’s disease (AD) and its efficacy is currently being tested in mild-to-moderate AD. Earlier studies reported reduced levels of serum anti-Ab antibodies in AD patients and the presence of these antibodies in IVIG. These observations led to clinical studies investigating the potential role of IVIG as a therapeutic agent in AD. In this study we wanted to investigate the potential of polyclonal Ab -specific antibodies (pAbs-Ab) present in IVIG preparations to modulate Ab aggregation, Ab-
mediated neurotoxicity and phagocytosis of fibrillar A b by BV-2 microglia in vitro. Methods: The pAbs-A b were purified from PrivigenÒ by Affinity Chromatography and their potential to inhibit Ab aggregation in a Thioflavin T fluorescence assay has been evaluated. Furthermore, the effect of pAbsAb on Ab-induced toxicity to SH-SY5Y cells and primary rat cortical neurons, as well as phagocytosis of fibrillar Ab by BV-2 mouse microglia was investigated. Results: In this study we show that approximately 0.1% pAbsAb are present in PrivigenÒ. These antibodies specifically bound to A b, inhibited its aggregation in Thioflavin T assay and appeared to prevent Ab-binding to neurons as visualized by confocal microscopy. Interestingly, not pAbs-Ab, but only the full IVIG preparation increased microglial phagocytosis of fibrillar Ab. Conclusions: Our results suggest that the b specific antibodies in PrivigenÒ may have an impact on Ab -driven processes in the pathogenesis of AD. In addition to the effects mediated by those antibodies, the established anti-inflammatory and immune-modulating properties of IVIG might further add to the beneficial effects observed in clinical studies.
P1-246
N-HETEROARYL-PIPERIDINYL-4-AMINES AS SELECTIVE GAMMA SECRETASE MODULATORS FOR THE POTENTIAL TREATMENT OF ALZHEIMER’S DISEASE
Thomas Luebbers, Anja Limberg, Synese Jolidon, Erwin Goetschi, Helmut Jacobsen, Luke Green, Alexander Flohr, Andrew Thomas, Henner Knust, Pascale David-Pierson, Karlheinz Baumann, F. Hoffmann-La Roche Ltd, Basel, Switzerland. Background: Alzheimer’s disease (AD) is the most common dementia in elderly. It is characterized by progressive memory loss accompanied by declining activities of daily living and neuropsychiatric symptoms and behavioral changes. In the brains of AD patients extracellular senile plaques composed of Aß peptides, intracellular neurofibrillary tangles consisting mainly of hyperphosphorylated tau and prominent neuronal loss are observed. Inhibition of g -secretase, the Aß-producing enzyme, is therapeutically unfavorable since it leads to Notch-related (another substrate of g -sercetase) toxicity in the thymus, gut and spleen. g -secretase modulators do not inhibit the enzyme but shift the formation of the toxic Aß42 peptide mainly to the formation of non-toxic Aß38 peptide without interfering with the processing of Notch. Methods: In the course of the optimization of the g -secretase modulators we tested the compounds in vitro in H4 cells overexpressing Aß42 and in vivo in an APP-transgenic mouse model as well as in nontransgenic rats for specific reduction of A b 42 in brain or CSF. Results: Starting from a previously reported g -secretase modulator 1 with an aminopyrimidine core we exchanged the central core by an aminotriazolopyridine core leading to highly potent compound 2 in vitro (IC 50 ¼ 92 nM). Replacement of the typical aromatic headgroup by a novel saturated aminopiperidine headgroup led to compound 3 with improved physicochemical properties and excellent brain activity in the transgenic mouse model as well as significant reduction of Aß42 in CSF of non-transgenic rats. Conclusions: A novel headgroup for g -secretase modulators was designed which provided compounds with excellent in vivo activity. We will describe detailed SAR and molecular properties for key compounds in this novel class.
P1-247
BETA-AMYLOID AGGREGATION HUMAN SYSTEMS PHARMACOLOGY MODELING: DEVELOPMENT AND APPLICATION TO PHARMACOLOGICAL TARGETS IN ALZHEIMER’S DISEASE
Timothy Nicholas1, Hugh Barton1, Yasong Lu1, Sridhar Duvvuri1, Tatiana Karelina2, Oleg Demin2, Kirill Zhudenkov2, Sergey Belykh2, Oleg Demin, Jr,2, 1Pfizer, Groton, Connecticut, United States; 2Institute for Systems Biology SPb, Moscow, Russia.