AU2006202899A1 - Prevention and treatment of amyloidogenic disease - Google Patents

Description

S&F Ref: 544876D2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Neuralab Limited, of 102 St. James Court Flatts, Smiths, FL04, Bermuda Dale B Schenk Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Prevention and treatment of amyloidogenic disease The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c PREVENTION AND TREATMENT OF O AMYLOIDOGENIC DISEASE 00

IN

TECHNICAL FIELD The invention resides in the technical fields of immunology and medicine.

BACKGROUND

Alzheimer's disease (AD) is a progressive disease resulting in senile dementia. See generally Selkoe, TINS 16, 403-409 (1993); Hardy et al., WO 92/13069; Selkoe, J. Neuropathol.

Exp. Neurol. 53, 438-447 (1994); Duff et al., Nature 373, 476- 477 (1995); Games et al., Nature 373, 523 (1995). Broadly speaking the disease falls into two categories: late onset, which occurs in old age (65 years) and early onset, which develops well before the senile period, i.e, between 35 and years. In both types of disease, the pathology is the same but the abnormalities tend to be more severe and widespread in cases beginning at an earlier age. The disease is characterized by two types of lesions in the brain, senile plaques and neurofibrillary tangles. Senile plaques are areas of disorganized neuropil up to 150 im across with extracellular amyloid deposits at the center visible by microscopic analysis of sections of brain tissue.

Neurofibrillary tangles are intracellular deposits of tau protein consisting of two filaments twisted about each other in pairs.

0 The principal constituent of the plaques is a peptide termed A3 or 0-amyloid peptide. A3 peptide is an internal fragment of 39-43 amino acids of a precursor protein termed ND amyloid precursor protein (APP). Several mutations within the APP protein have been correlated with the presence of Alzheimer's disease. See, Goate et al., Nature 349, C0 704) (1991) (valine 717 to isoleucine); Chartier Harlan et al.

00 C\ Nature 353, 844 (1991)) (valine 71 7 to glycine); Murrell et al., Science 254, 97 (1991) (valine 71 7 to phenylalanine); S) Mullan et al., Nature Genet. 1, 345 (1992) (a double mutation 0 changing lysines 9 5 -methionine 5 9 6 to asparagines 95 -leucine 5 9 6 Such mutations are thought to cause Alzheimer's disease by increased or altered processing of APP to A,3, particularly processing of APP to increased amounts of the long form of Afl Aol-42 and A01-43). Mutations in other genes, such as the presenilin genes, PS1 and PS2, are thought indirectly to affect processing of APP to generate increased amounts of long form A3 (see Hardy, TINS 20, 154 (1997)). These observations indicate that A0, and particularly its long form, is a 3 causative element in Alzheimer's disease.

McMichael, EP 526,511, proposes administration of homeopathic dosages (less than or equal to 10 2 mg/day) of A,3 to patients with preestablished AD. In a typical human with about 5 liters of plasma, even the upper limit of this dosage would be expected to generate a concentration of no more than 2 pg/ml. The normal concentration of A,3 in human plasma is typically in the range of 50-200 pg/ml (Seubert et al., Nature 359, 325-327 (1992)). Because EP 526,511's proposed dosage would barely alter the level of endogenous circulating A3 and because EP 526,511 does not recommend use of an adjuvant, it seems implausible that any therapeutic benefit would result.

By contrast, the present invention is directed inter alia to treatment of Alzheimer's and other amyloidogenic diseases by administration of A3 or other immunogen to a patient under conditions that generate a beneficial immune response in the patient. The invention thus fulfills a longstanding need for therapeutic regimes for preventing or ameliorating the neuropathology of Alzheimer's disease.

SUMMARY OF THE CLAIMED INVENTION in one aspect, the invention provides methods of preventing., or treating a disease characterized by amyloid deposition in a patient. Such methods entail inducing an immune response against a peptide component of an amyloid deposit in the patient. Such induction can be active by administration of an irnmunogen or passive by administration of an antibody or an 00 ciactive fragment or derivative of the antibody. In some ci patients, the amyloid deposit is aggregated A03 peptide and ID the disease is Alzheimer's disease. In some methods, the patient is asymuptomatic. In some methods, the patient is under 50 years of age. In some methods, the patient has inherited risk factors indicating susceptibility to Alzheimer's disease. Such risk factors include variant alleles in presenilin gene PS1 or PS2 and variant forms of APP. In other methods, the patient has no known risk factors for Alzheimer's disease.

For treatment of patients suffering from Alzheimer's disease, one treatment regime entails administering a dose of A,8 peptide to the patient to induce the immune response. In some methods, the Af3 peptide is administered with an adjuvant that enhances the immune response to the A0 peptide. In some methods, the adjuvant is alum. In some methods, the adjuvant is MPL. The dose of A03 peptide administered to the patient is typically at least 1 or 10 Mg, if administered with adjuvant, and at least 50 Mg if administered without adjuvant. In some methods, the dose is at least 100 Mg.

In some methods, the AO3 peptide is A431-42. In some methods, the M4 peptide is administered in aggregated form.

In other methods, the A,8 peptide is administered in dissociated form. In some methods, the therapeutic agent is an effective dose of a nucleic acid encoding A,3 or an active fragment or derivative thereof. The nucleic acid encoding A03 or fragment thereof is expressed in the patient to produce A43 or the active fragment thereof, which induces the immune response. In some such methods, the nucleic acid is administered through the skin, optionally via a patch. In some methods, a therapeutic agent is identified by screening a S library of compounds to identify a compound reactive with antibodies to A3, and administering the compound to the patient to induce the immune response.

In some methods, the immune response is directed to aggregated A3 peptide without being directed to dissociated A3 CA peptide. For example, the immune response can comprise >h antibodies that bind to aggregated A/ peptide without binding 00 C<I to dissociated A3 peptide. In some methods, the immune response comprises T-cells that bind to A3 complexed with MCH1 or MHCII on CD8 or CD4 cells. In other methods, the immune response is induced by administering an antibody to A3 to the patient. In some'methods, the immune response is induced by removing T-cells from the patient, contacting the T-cells with A0 peptide under conditions in which the T-cells are primed, and replacing the T-cells in the patient.

The therapeutic agent is typically administered orally, intranasally, intradermally, subcutaneously, intramuscularly, topically or intravenously. In some methods, the patient is monitored followed administration to assess the immune response. If the monitoring indicates a reduction of the immune response over time, the patient can be given one or more further doses of the agent.

In another aspect, the invention provides pharmaceutical compositions comprising A0 and an excipient suitable for oral and other routes of administration. The invention also provides pharmaceutical compositions comprising an agent effective to induce an immunogenic response against A3 in a patient, and a pharmaceutically acceptable adjuvant. In some such compositions, the agent is A3 or an active fragment thereof. In some compositions, the adjuvant comprises alum.

In some compositions, the adjuvant comprises an oil-in-water emulsion. In some compositions, the A3 or active fragment is a component of a polylactide polyglycolide copolymer (PLPG) or other particle. The invention further provides compositions comprising A3 or an active fragment linked to a conjugate molecule that promotes delivery of A3 to the bloodstream of a patient and/or promotes an immune response against A6. For example, the conjugate can serve to promote an immune response ID 0 against A/3. In some compositions, the conjugate is cholera toxin. In some compositions, the conjugate is an immunoglobulin. In some compositions, the conjugate is ND attenuated diphtheria toxin CRM 197 (Gupta, Vaccine 15, 1341-3 (1997).

The invention also provides pharmaceutical compositions C0 comprising an agent effect to induce an immunogenic response 00 against A3 in a patient with the proviso that the composition is free of Complete Freund's adjuvant. The invention also IND provides compositions comprising a viral vector encoding A3 or S a an active fragment thereof effective to induce an immune response against A3. Suitable viral vectors include herpes, adenovirus, adenoassociated virus, a retrovirus, sindbis, semiliki forest virus, vaccinia or avian pox.

The invention further provides methods of preventing or treating Alzheimer's disease. In such methods, an effective dose of A43 pepti.de is administered to a patient. The invention further provides for the use of A43, or an antibody thereto, in the manufacture of a medicament for prevention or treatment of Alzheimer's disease.

In another aspect, the invention provides methods of assessing efficacy of an Alzheimer's treatment method in a patient. In these methods, a baseline amount of antibody specific for A43 peptide is determined in a tissue sample from the patient before treatment with an agent. An amount of antibody specific for A43 peptide in the tissue sample from the patient after treatment with the agent is compared to the baseline amount of A4 peptide-specific antibody. An amount of A3 peptide-specific antibody measured after the treatment that is significantly greater than the baseline amount of Af3 peptide-specific antibody indicates a positive treatment outcome.

In others methods of assessing efficacy of an Alzheimer's treatment method in a patient, a baseline amount of antibody specific for Aa peptide in a tissue sample from a patient before treatment with an agent is determined. An amount of antibody specific for A3 peptide in the tissue sample from the subject after treatment with the agent is compared to the 0 baseline amount of A0 peptide-specific antibody. A reduction or lack of significant difference between the amount of A/6 h- peptide-specific antibody measured after the treatment IND compared to the baseline amount of Af/ peptide-specific antibody indicates a negative treatment outcome.

In other methods of assessing efficacy of an Alzheimer's \h disease treatment method in a patient a control amount of 00 C antibody specific for A0 peptide is determined in tissue c- samples from a control population. An amount of antibody Sspecific for A4 peptide in a tissue sample from the patient S after administering an agent is compared to the control amount of A0 peptide-specific antibody. An amount of A3 peptide-specific antibody measured after the treatment that is significantly greater than the control amount of A3 peptide-specific antibody indicates a positive treatment outcome.

In other methods of assessing efficacy of an Alzheimer's treatment method in a patient, a control amount of antibody specific for A3 peptide in tissues samples from a control population is determined. An amount of antibody specific for A3 peptide in a tissue sample from the patient after administering an agent is compared to the control amount of A3 peptide-specific antibody. A lack of significant difference between the amount of A0 peptide-specific antibody measured after beginning said treatment compared to the control amount of.A3 peptide-specific antibody indicates a negative treatment outcome.

Other methods of monitoring Alzheimer's disease or susceptibility thereto in a patient, comprise detecting an immune response against A peptide in a sample from the patient. In some such methods, the patient is being administered an agent effective to treat or prevent Alzheimer's disease, and the level of the response determines the future treatment regime of the patient.

In other methods of assessing efficacy of an Alzheimer's treatment method in a patient a value for an amount of antibody specific for A0 peptide in tissue sample from a patient who has been treated with an agent is determined. The Svalue is compared with a control value determined from a population of patient experiencing amelioriation of, or freedom from, symptoms of Alzheimer's disease due to treatment with the agent. A value in the patient at least equal to the control value indicates a positive response to treatment.

The invention further provides diagnostic kits for C0 performing the above methods. Such kits typically include a 00 reagent that specifically binds to antibodies to A or which stimulates proliferation of T-cells reactive with AO.

0 0 BRIEF DESCRIPTION OF THE FIGURES Fig. 1: Antibody titer after injection of transgenic mice with A,1-42.

Fig. 2: Amyloid burden in the hippocampus. The percentage of the area of the hippocampal region occupied by amyloid plaques, defined by reactivity with the A$-specific mA3 3D6, was determined by computer-assisted quantitative image analysis of immunoreacted brain sections. The values for individual mice are shown sorted by treatment group. The horizontal line for each grouping indicates the median value 0 of the distribution.

Fig 3: Neuritic dystrophy in the hippocampus. The percentage of the area of the hippocampal region occupied by dystrophic neurites, defined by their reactivity with the human APP-specific mA3 8E5, was determined by quantitative computer-assisted image analysis of immunoreacted brain sections. The values for individual mice are shown for the AN1792-treated group and the PBS-treated control group. The horizontal line for each grouping indicates the median value of the distribution.

Fig. 4: Astrocytosis in the retrosplenial cortex. The percentage of the area of the cortical region occupied by glial fibrillary acidic protein (GFAP)-positive astrocytes was determined by quantitative computer-assisted image analysis of immunoreacted brain sections. The values for individual mice are shown sorted by treatment group and median group values are indicated by horizontal lines.

J

SFig. 5: Geometric mean antibody titers to A81-42 following immunization with a range of eight doses of AN1792 containing Z 0.14, 0.4, 1.2, 3.7, 11, 33, 100, or 300 pg.

IND Fig. 6: Kinetics of antibody response to AN1792 immunization. Titers are expressed as geometric means or values for the 6 animals in each group.

Ch Fig. 7: Quantitative image analysis of the cortical 00 amyloid burden in PBS- and AN1792-treated mice.

Fig. 8: Quantitative image analysis of the neuritic plaque burden in PBS- and AN1792-treated mice.

0 Fig. 9: Quantitative image analysis of the percent of the retrosplenial cortex occupied by astrocytosis in PBS- and AN1792-treated mice.

Fig. 10: Lymphocyte Proliferation Assay on spleen cells from AN1792-treated (upper panel) or PBS-treated (lower panel).

Fig. 11: Total A3 levels in the cortex. A scatterplot of individual A profiles in mice immunized with A0 or APP derivatives combined with Freund's adjuvant.

Fig. 12: Amyloid burden in the cortex was determined by quantitative image analysis of immunoreacted brain sections for mice immunized with the A0 peptide conjugates A81-5, A31- 12, and A313-28; the full length A0 aggregates AN1792 (A01-42) and AN1528 (A01-40) and the PBS-treated control group.

Fig. 13: Geometric mean titers of Al-specific antibody for groups of mice immunized with A, or APP derivatives combined with Freund's adjuvant.

Fig. 14: Geometric mean titers of A43-specific antibody for groups of guinea pigs immunized with AN1792, or a palmitoylated derivative thereof, combined with various adjuvants.

Fig: 15: A43 levels in the cortex of 12-month old PDAPP mice treated with AN1792 or AN1528 with different adjuvants.

DEFINITIONS

The term "substantial identity" means that two peptide sequences, when optimally aligned, such as by the programs GAP or BESTFIT using default gap weights, share at least percent sequence identity, preferably at least 80 or percent sequence identity, more preferably at least 95 percent sequence identity or more 99 percent sequence identity ID or higher) Preferably, residue positions which are not identical differ by conservative amino acid substitutions.

For sequence comparison, typically one sequence acts as a reference sequence, to which test sequences are compared.

00 ci When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates ID are designated, if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters.

Optimal alignment of sequences for comparison can be conducted, by the local homology algorithm of Smith Waterman, Adv. Appi. M4ath. 2:482 (1981), by the homology alignment algorithm of Needleman Wunsch, J. Mol. Biol.

48:443 (1970) by the search for similarity method of Pearson Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, WI) or by visual inspection (see generally Ausubel et al., supra). one example of algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mod. Biol. 215:403-410 (1990) Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/). Typically, default program parameters can be used to perform the sequence comparison, although customized parameters can also be used. For amino acid sequences, the BLASTP program uses as defaults a wordlength of 3, an expectation of 10, and the BLOSUM62 scoring matrix (see Henikoff Henikoff, Proc. Natl.

Acad. Sci. USA 89, 10915 (1989)) For purposes of classifying amino acids substitutions as conservative or nonconservative, amino acids are grouped as Z follows: Group I (hydrophobic sidechains): norleucine, met, IND ala, val, leu, ile; Group II (neutral hydrophilic side chains): cys, ser, thr; Group III (acidic side chains): asp, glu; Group IV (basic side chains): asn, gln, his, lys, arg; Ch Group V (residues influencing chain orientation): gly, pro; OO and Group VI (aromatic side chains): trp, tyr, phe.

S Conservative substitutions involve substitutions between amino ID acids in the same class. Non-conservative substitutions S constitute exchanging a member of one of these classes for a member of another.

Therapeutic agents of the invention are typically substantially pure. This means that an agent is typically at least about 50% w/w (weight/weight) purity, as well as being substantially free from interfering proteins and contaminants.

Sometimes the agents are at least about 80% w/w and, more preferably at least 90 or about 95% w/w purity. However, .using conventional protein purification techniques, homogeneous peptides of at least 99% w/w can be obtained.

Specific binding between two entities means an affinity of at least 106, 10 7 108, 10 9

M-

1 or 101 0

M-

1 Affinities greater than 108 M- 1 are preferred.

The term "antibody" is used to include intact antibodies and binding fragments thereof. Typically, fragments compete with the intact antibody from which they were derived for specific binding to an antigen. Optionally, antibodies or binding fragments thereof, can be chemically conjugated to, or expressed as, fusion proteins with other proteins.

APP

6 9 5

APP

7 51 and APP 770 refer, respectively, to the 695, 751, and 770 amino acid residue long polypeptides encoded by the human APP gene. See Kang et al., Nature 325, 773 (1987); Ponte et al., Nature 331, 525 (1988); and Kitaguchi et al., Nature 331, 530 (1988). Amino acids within the human amyloid precursor protein (APP) are assigned numbers according to the sequence of the APP770 isoform. Terms such as A039, A4340, A341, A342 and A043 refer to an A43 peptide containing amino acid residues 1-39, 1-40, 1-41, 1-42 and 1-43.

0 The term "epitope" or "antigenic determinant" refers to a site on an antigen to which B and/or T cells respond. B-cell epitopes can be formed both from contiguous amino acids or ID noncontiguous amino acids juxtaposed by tertiary folding of a protein. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents whereas >h epitopes formed by tertiary folding are typically lost on 00 Ci treatment with denaturing solvents. An epitope typically ^c includes at least 3, and more usually, at least 5 or 8-10 amino acids in a unique spatial conformation. Methods of determining spatial conformation of epitopes include, for example, x-ray crystallography and 2-dimensional nuclear magnetic resonance. See, Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66, Glenn E. Morris, Ed.

(1996). Antibodies that recognize the same epitope can be identified in a simple immunoassay showing the ability of one antibody to block the binding of another antibody to a target antigen. T-cells recognize continuous epitopes of about nine amino acids for CD8 cells or about 13-15 amino acids for CD4 cells. T cells that recognize the epitope can be identified by in vitro assays that measure antigen-dependent proliferation, as determined by 3H-thymidine incorporation by primed T cells in response to an epitope (Burke et al., J.

Inf. Dis. 170, 1110-19 (1994)), by antigen-dependent killing (cytotoxic T lymphocyte assay, Tigges et al., J. Immunol. 156, 3901-3910) or by cytokine secretion.

The term "immunological" or "immune" response is the development of a beneficial humoral (antibody mediated) and/or a cellular (mediated by antigen-specific T cells or their secretion products) response directed against an amyloid peptide in a recipient patient. Such a response can be an active response induced by administration of immunogen or a passive response induced by administration of antibody or primed T-cells. A cellular immune response is elicited by the presentation of polypeptide epitopes in association with Class I or Class II MHC molecules to activate antigen-specific CD4' T helper cells and/or CD8 cytotoxic T cells. The response may also involve activation of monocytes, macrophages, NK cells, basophils, dendritic cells, astrocytes, microglia cells, eosinophils or other components of innate immunity.

The presence of a cell-mediated immunological response can be QD determined by proliferation assays (CD4 T cells) or CTL 0- (cytotoxic T lymphocyte) assays (see Burke, supra; Tigges, supra). The relative contributions of humoral and cellular CA responses to the protective or therapeutic effect of an 00 immunogen can be distinguished by separately isolating IgG and S T-cells from an immunized syngeneic animal and measuring D protective or therapeutic effect in a second subject.

SAn "immunogenic agent" or "immunogen" is capable of inducing an immunological response against itself on administration to a patient, optionally in conjunction with an adjuvant.

The term "naked polynucleotide" refers to a polynucleocide not complexed with colloidal materials. Naked polynucleotides are sometimes cloned in a plasmid vector.

The term "adjuvant" refers to a compound that when administered in conjunction with an antigen augments the immune response to the antigen, but when administered alone does not generate an immune response to the antigen.

Adjuvants can augment an immune response by several mechanisms including lymphocyte recruitment, stimulation of B and/or T cells, and stimulation of macrophages.

The term "patient" includes human and other mammalian subjects that receive either prophylactic or therapeutic treatment.

Disaggregated or monomeric Aj3 means soluble, monomeric peptide units of A3. One method to prepare monomeric A0 is to dissolve lyophilized peptide in neat DMSO with sonication.

The resulting solution is centrifuged to remove any nonsoluble particulates. Aggregated AO is a mixture of oligomers in which the monomeric units are held together by noncovalent bonds.

Compositions or methods "comprising" one or more recited elements may include other elements not specifically recited.

For example, a composition that comprises AO peptide encompasses both an isolated AO peptide and A0 peptide as a component of a larger polypeptide sequence.

DETAILED DESCRIPTION I. General The invention provides pharmaceutical compositions and C0 methods for prophylactic and therapeutic treatment of diseases OO characterized by accumulation of amyloid deposits. Amyloid Sdeposits comprise a peptide aggregated to an insoluble mass.

k)D The nature of the peptide varies in different diseases but in 0 3 most cases, the aggregate has a -pleated sheet structure and stains with Congo Red dye. Diseases characterized by amyloid deposits include Alzheimer's disease both late and early onset. In both diseases, the amyloid deposit comprises a peptide termed A, which accumulates in the brain of affected individuals. Examples of some other diseases characterized by amyloid deposits are SAA amyloidosis, hereditary Icelandic syndrome, multiple myeloma, and spongiform encephalopathies, including mad cow disease, Creutzfeldt Jakob disease, sheep scrapie, and mink spongiform encephalopathy (see Weissmann et 0 al., Curr. Opin. Neurobiol. 7, 695-700 (1997); Smits et al., Veterinary Quarterly 19, 101-105 (1997); Nathanson et al., Am.

J. Epidemiol. 145, 959-969 (1997)). The peptides forming the aggregates in these diseases are serum amyloid A, cystantin C, IgG kappa light chain respectively for the first three, and prion protein for the others.

II. Therapeutic Agents 1. Alzheimer's Disease Therapeutic agents for use in the present invention induce an immune response against A/ peptide. These agents include A3 peptide itself and variants thereof, analogs and mimetics of A3 peptide that induce and/or crossreact with antibodies to A3 peptide, and antibodies or T-cells reactive with A3 peptide. Induction of an immune response can be active as when an immunogen is administered to induce antibodies or Tcells reactive with A8 in a patient, or passive, as when an antibody is administered that itself binds to A,3 in patient.

SA?, also known as 3-amyloid peptide, or A4 peptide (see US CIl 4,666,829; Glenner Wong, Biochem. Biophys. Res. Comnmun. 120, 1131 (1984)), is a peptide of 39-43 amino acids, which is the principal component of characteristic plaques of Alzheimer's S 5 disease. AO is generated by processing of a larger protein APP by two enzymes, termed 0 and 7 secretases (see Hardy, TINS 0 20, 154 (1997)). Known mutations in APP associated with O Alzheimer's disease occur proximate to the site of 3 or 7 00 secretase, or within A0. For example, position 717 is C- 10 proximate to the site of y-secretase cleavage of APP in its k0 I processing to AO, and positions 670/671 are proximate to the site of 3-secretase cleavage. It is believed that the mutations cause AD disease by interacting with the cleavage reactions by which A? is formed so as to increase the amount of the 42/43 amino acid form of A6 generated.

AO has the unusual property that it can fix and activate both classical and alternate complement cascades. In particular, it binds to Clq and ultimately to C3bi. This association facilitates binding to macrophages leading to activation of B cells. In addition, C3bi breaks down further and then binds to CR2 on B cells in a T cell dependent manner leading to a 10,000 increase in activation of these cells.

This mechanism causes AO to generate an immune response in excess of that of other antigens.

The therapeutic agent used in the claimed methods can be any of the naturally occurring forms of A,6 peptide, and particularly the human forms A339, A040, A641, A642 or A/343). The sequences of these peptides and their relationship to the APP precursor are illustrated by Fig. 1 of Hardy et al., TINS 20, 155-158 (1997). For example, A,342 has the sequence: H2N-Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His- Gln-Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-Gly- Ala-Ile-Ile-Gly-Leu-Met-Val-Gly-Gly-Val-Val-IIe-Ala-OH.

A341, A840 and A339 differ from A042 by the omission of Ala, Ala-lie, and Ala-Ile-Val respectively from the C-terminal end.

A043 differs from A,842 by the presence of a threonine residue at the C-terminus. The therapeutic agent can also be an active fragment or analog of a natural A3 peptide that Scontains an epitope that induces a similar protective or therapeutic immune response on administration to a human.

Immunogenic fragments typically have a sequence of at least 3, 6, 10 or 20 contiguous amino acids from a natural peptide.

Immunogenic fragments include A,1-5, 1-6, 1-12, 13-28, 17-28, 00 25-25, 35-40 and 35-42. Fragments from the N-terminal half of A3 are preferred in some methods. Analogs include allelic, species and induced variants. Analogs typically differ from Snaturally occurring peptides at one or a few positions, often ci by virtue of conservative substitutions. Analogs typically exhibit at least 80 or 90% sequence identity with natural pepoides. Some analogs also include unnatural amino acids or modifications of N or C terminal amino acids. Examples of unnatural amino acids are a,a-disubstituted amino acids, Nalkyl amino acids, lactic acid, 4-hydroxyproline, 7carboxyglutamate, e-N,N,N-trimethyllysine, e-N-acetyllysine, O-phosphoserine, N-acetylserine, N-formylmethionine, 3methylhistidine, 5-hydroxylysine, w-N-methylarginine.

Fragments and analogs can be screened for prophylactic or therapeutic efficacy in transgenic animal models as described below.

AO, its fragments, analogs and other amyloidogenic peptides can be synthesized by solid phase peptide synthesis or recombinant expression, or can be obtained from natural sources. Automatic peptide synthesizers are commercially available from numerous suppliers, such as Applied Biosystems, Foster City, California. Recombinant expression can be in bacteria, such as E. coli, yeast, insect cells or mammalian cells. Procedures for recombinant expression are described by Sambrook et al., Molecular Cloning: A Laboratory Manual Press, NY 2d ed., 1989). Some forms of A43 peptide are also available commercially American Peptides Company, Inc., Sunnyvale, CA and California Peptide Research, Inc. Napa, CA).

Therapeutic agents also include longer polypeptides that include, for example, an A peptide, active fragment or analog together with other amino acids. For example, Afl peptide can C be present as intact APP protein or a segment thereof, such as the C-100 fragment that begins at the N-terminus of A0 and continues to the end of APP. Such polypeptides can be screened for prophylactic or therapeutic efficacy in animal models as described below. The A3 peptide, analog, active C0 fragment or other polypeptide can be administered in 00 associated form as an amyloid peptide) or in dissociated form. Therapeutic agents also include multimers 0C 10 of monomeric immunogenic agents.

SIn a further variation, an immunogenic peptide, such as A0, C) can be presented as a viral or bacterial vaccine. A nucleic acid encoding the immunogenic peptide is incorporated into a genome or episome of the virus or bacteria. Optionally, the nucleic acid is incorporated in such a manner that the immunogenic peptide is expressed as a secreted protein or as a fusion protein with an outersurface protein of a virus or a transmembrane protein of a bacteria so that the peptide is displayed. Viruses or bacteria used in such methods should be nonpathogenic or attenuated. Suitable viruses include adenovirus, HSV, vaccinia and fowl pox. Fusion of an immunogenic peptide to HBsAg of HBV is particularly suitable.

Therapeutic agents also include peptides and other compounds that do not necessarily have a significant amino acid sequence similarity with A0 but nevertheless serve as mimetics of A,3 and induce a similar immune response. For example, any peptides and proteins forming 0-pleated sheets can be screened for suitability. Anti-idiotypic antibodies against monoclonal antibodies to A or other amyloidogenic peptides can also be used. Such anti-Id antibodies mimic the antigen and generate an immune response to it (see Essential Immunology (Roit ed., Blackwell Scientific Publications, Palo Alto, 6th p.

181).

Random libraries of peptides or other compounds can also be screened for suitability. Combinatorial libraries can be produced for many types of compounds that can be synthesized in a step-by-step fashion. Such compounds include polypeptides, beta-turn mimetics, polysaccharides, phospholipids, hormones, prostaglandins, steroids, aromatic CI compounds, heterocyclic compounds, benzodiazepines, oligomeric SN-substituted glycines and oligocarbamates. Large combinatorial libraries of the compounds can be constructed by 0 5 the encoded synthetic libraries (ESL) method described in Affymax, WO 95/12608, Affymax, WO 93/06121, Columbia C0 University, WO 94/08051, Pharmacopeia, WO 95/35503 and 0 Scripps, WO 95/30642 (each of which is incorporated by reference for all purposes). Peptide libraries can also be C 10 generated by phage display methods. See, Devlin, WO S91/18980.

C) Combinatorial libraries and other compounds are initially screened for suitability by determining their capacity to bind to antibodies or lymphocytes (B or T) known to be specific for A3 or other amyloidogenic peptides. For example, initial screens can be performed with any polyclonal sera or monoclonal antibody to A,3 or other amyloidogenic peptide.

Compounds identified by such screens are then further analyzed for capacity to induce antibodies or reactive lymphocytes to A3 or other amyloidogenic peptide. For example, multiple dilutions of sera can be tested on microtiter plates that have been precoated with A3 peptide and a standard ELISA can be performed to test for reactive antibodies to A3. Compounds can then be tested for prophylactic and therapeutic efficacy in transgenic animals predisposed to an amyloidogenic disease, as. described in the Examples. Such animals include, for example, mice bearing a 717 mutation of APP described by Games et al., supra, and mice bearing a Swedish mutation of APP such as described by McConlogue et al., US 5,612,486 and Hsiao et al., Science 274, 99 (1996); Staufenbiel et al., Proc. Natl.

Acad. Sci. USA 94, 13287-13292 (1997); Sturchler-Pierrat et al., Proc. Natl. Acad. Sci. USA 94, 13287-13292 (1997); Borchelt et al., Neuron 19, 939-945 (1997)). The same screening approach can be used on other potential agents such as fragments of A0, analogs of A3 and longer peptides including A3, described above.

Therapeutic agents of the invention also include antibodies that specifically bind to A3. Such antibodies can be monoclonal or polyclonal. Some such antibodies bind Cl specifically to the aggregated form of A3 without binding to the dissociated form. Some bind specifically to the dissociated form without binding to the aggregated form. Some 0 5 bind to both aggregated and dissociated forms. The production of non-human monoclonal antibodies, murine or rat, can Ch be accomplished by, for example, immunizing the animal with 00 A3. See Harlow Lane, Antibodies, A Laboratory Manual (CSHP SNY, 1988) (incorporated by reference for all purposes). Such CI 10 an immunogen can be obtained from a natural source, by Speptides synthesis or by recombinant expression.

eg Humanized forms of mouse antibodies can be generated by linking the CDR regions of non-human antibodies to human constant regions by recombinant DNA techniques. See Queen et al., Proc. Natl. Acad. Sci. USA 86, 10029-10033 (1989) and WO 90/07861 (incorporated by reference for all purposes).

Human antibodies can be obtained using phage-display methods. See, Dower et al., WO 91/17271; McCafferty et al., WO 92/01047. In these methods, libraries of phage are produced in which members display different antibodies on their outersurfaces. Antibodies are usually displayed as Fv or Fab fragments. Phage displaying antibodies with a desired specificity are selected by affinity enrichment to AO, or fragments thereof. Human antibodies against A3 can also be produced from non-human transgenic mammals having transgenes encoding at least a segment of the human immunoglobulin locus and an inactivated endogenous immunoglobulin locus. See, Lonberg et al., W093/12227 (1993); Kucherlapati, WO 91/10741 (1991) (each of which is incorporated by reference in its entirety for all purposes). Human antibodies can be selected by competitive binding experiments, or otherwise, to have the same epitope specificity as a particular mouse antibody. Such antibodies are particularly likely to share the useful functional properties of the mouse antibodies.

Human polyclonal antibodies can also be provided in the form of serum from humans immunized with an immunogenic agent.

Optionally, such polyclonal antibodies can be concentrated by 0 affinity purification using A3 or other amyloid peptide as an 4C affinity reagent.

Human or humanized antibodies can be designed to have IgG, IgD, IgA and IgE constant region, and any isotype, including IgGi, IgG2, IgG3 and IgG4. Antibodies can be expressed as tetramers containing two light and two heavy chains, as separate heavy chains, light chains, as Fab, Fab' F(ab') 2 and Fv, or as single chain antibodies in which heavy and light 00 CI chain variable domains are linked through a spacer.

C'q 10 Therapeutic agents for use in the present methods also I include T-cells that bind to Af peptide. For example, T-cells can be activated against A/ peptide by expressing a human MHC class I gene and a human f-2-microglobulin gene from an insect cell line, whereby an empty complex is formed on the surface of the cells and can bind to A3 peptide. T-cells contacted with the cell line become specifically activated against the peptide. See Peterson et al., US 5,314,813. Insect cell lines expressing an MHC class II antigen can similarly be used to activate CD4 T cells.

2. Other Diseases The same or analogous principles determine production of therapeutic agents for treatment of other amyloidogenic diseases. In general, the agents noted above for use in treatment of Alzheimer's disease can also be used for treatment early onset Alzheimer's disease associated with Down's syndrome. In mad cow disease, prion peptide, active fragments, and analogs, and antibodies to prion peptide are used in place of A,3 peptide, active fragments, analogs and antibodies to A3 peptide in treatment of Alzheimer's disease.

In treatment of multiple myeloma, IgG light chain and analogs and antibodies thereto are used, and so forth in other diseases.

3. Carrier Proteins Some agents for inducing an immune response contain the appropriate epitope for inducing an immune response against amyloid deposits but are too small to be immunogenic. In this Ssituation, a peptide immunogen can be linked to a suitable CI carrier to help elicit an immune response. Suitable carriers Sinclude serum albumins, keyhole limpet hemocyanin, immunoglobulin molecules, thyroglobulin, ovalbumin, tetanus 0 5 toxoid, or a toxoid from other pathogenic bacteria, such as diphtheria, E. coli, cholera, or H. pylori, or an attenuated Stoxin derivative. Other carriers for stimulating or enhancing O an immune response include cytokines such as IL-1, IL-1 c and c 3 peptides, IL-2, yINF, IL-10, GM-CSF, and chemokines, such as Cl 10 MlPla and and RANTES. Immunogenic agents can also be linked Sto peptides that enhance transport across tissues, as described in O'Mahony, WO 97/17613 and WO 97/17614.

Immunogenic agents can be linked to carriers by chemical crosslinking. Techniques for linking an immunogen to a carrier include the formation of disulfide linkages using Nsuccinimidyl-3-(2-pyridyl-thio) propionate (SPDP) and succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) (if the peptide lacks a sulfhydryl group, this can be provided by addition of a cysteine residue). These reagents create a disulfide linkage between themselves and peptide cysteine resides on one protein and an amide linkage through the e-amino on a lysine, or other free amino group in other amino acids. A variety of such disulfide/amide-forming agents are described by Immun. Rev. 62, 185 (1982). Other bifunctional coupling agents form a thioether rather than a dipulfide linkage. Many of these thio-ether-forming agents are commercially available and include reactive esters of 6maleimidocaproic acid, 2-bromoacetic acid, and 2-iodoacetic acid, 4-(N-maleimido-methyl)cyclohexane-1-carboxylic acid.

The carboxyl groups can be activated by combining them with succinimide or l-hydroxyl-2-nitro-4-sulfonic acid, sodium salt.

Immunogenic peptides can also be expressed as fusion proteins with carriers. The immunogenic peptide can be linked at the amino terminus, the carboxyl terminus, or internally to the carrier. Optionally, multiple repeats of the immunogenic peptide can be present in the fusion protein.

0 4. Nucleic Acid Encoding Immunoqens c- Immune responses against amyloid deposits can also be induced by administration of nucleic acids encoding A3 peptide or other peptide immunogens. Such nucleic acids can be DNA or RNA. A nucleic acid segment encoding the immunogen is typically linked to regulatory elements, such as a promoter and enhancer, that allow expression of the DNA segment in the intended target cells of a patient. For expression in blood 00 Cl cells, as is desirable for induction of an immune response, c- 10 promoter and enhancer elements from light or heavy chain CN immunoglobulin genes or the CMV major intermediate early Spromoter and enhancer are suitable to direct expression. The linked regulatory elements and coding sequences are often cloned into a vector.

A number of viral vector systems are available including retroviral systems (see, Lawrie and Tumin, Cur. Opin.

Genet. Develop. 3, 102-109 (1993)); adenoviral vectors (see, Bett et al., J. Virol. 67, 5911 (1993)); adenoassociated virus vectors (see, Zhou et al., J. Exp. Med.

179, 1867 (1994)), viral vectors from the pox family including vaccinia virus and the avian pox viruses, viral vectors from the alpha virus genus such as those derived from Sindbis and Semliki Forest Viruses (see, Dubensky et al., J. Virol.

508-519 (1996)), and papillomaviruses (Ohe et al., Human Gene Therapy 6, 325-333 (1995); Woo et al., WO 94/12629 and Xiao Brandsma, Nucleic Acids. Res. 24, 2630-2622 (1996)).

DNA encoding an immunogen, or a vector containing the same, can be packaged into liposomes. Suitable lipids and related analogs are described by US 5,208,036, 5,264,618, 5,279,833 and 5,283,185. Vectors and DNA encoding an immunogen can also be adsorbed to or associated with particulate carriers, examples of which include polymethyl methacrylate polymers and polylactides and poly(lactide-co-glycolides), see, McGee et al., J. Micro Encap. (1996).

Gene therapy vectors or naked DNA can be delivered in vivo by administration to an individual patient, typically by systemic administration intravenous, intraperitoneal, nasal, gastric, intradermal, intramuscular, subdermal, or 0 intracranial infusion) or topical application (see e.g., Cq US 5,399,346). DNA can also be administered using a gene Sgun. See Xiao Brandsma, supra. The DNA encoding an immunogen is precipitated onto the surface of microscopic

NO

metal beads. The microprojectiles are accelerated with a shock wave or expanding helium gas, and penetrate tissues to a 0^ depth of several cell layers. For example, The AccelTh Gene Delivery Device manufactured by Agacetus, Inc. Middleton WI is 00 0C suitable. Alternatively, naked DNA can pass through skin into C 10 the blood stream simply by spotting the DNA onto skin with N chemical or mechanical irritation (see WO 95/05853).

SIn a further variation, vectors encoding immunogens can be

CN

delivered to cells ex vivo, such as cells explanted from an individual patient lymphocytes, bone marrow aspirates, tissue biopsy) or universal donor hematopoietic stem cells, followed by reimplantation of the cells into a patient, usually after selection for cells which have incorporated the vector.

III. Patients Amenable to Treatment Patients amenable to treatment include individuals at risk of disease but not showing symptoms, as well as patients presently showing symptoms. In the case of Alzheimer's disease, virtually anyone is at risk of suffering from Alzheimer's disease if he or she lives long enough.

Therefore, the present methods can be administered prophylactically to the general population without any assessment of the risk of the subject patient. The present methods are especially useful for individuals who do have a known genetic risk of Alzheimer's disease. Such individuals include those having relatives who have experienced this disease, and those whose risk is determined by analysis of genetic or biochemical markers. Genetic markers of risk toward Alzheimer's disease include mutations in the APP gene, particularly mutations at position 717 and positions 670 and 671 referred to as the Hardy and Swedish mutations respectively (see Hardy, TINS, supra). Other markers of risk are mutations in the presenilin genes, PS1 and PS2, and ApoE4, Sfamily history of AD, hypercholesterolemia or atherosclerosis.

ci Individuals presently suffering from Alzheimer's disease can Sbe recognized from characteristic dementia, as well as the presence of risk factors described above. In addition, a

INO

S 5 number of diagnostic tests are available for identifying individuals who have AD. These include measurement of CSF tau 0e and A342 levels. Elevated tau and decreased A42 levels 0O signify the presence of AD. Individuals suffering from 00 C Alzheimer's disease can also be diagnosed by MMSE or ADRDA Ci 10 criteria as discussed in the Examples section.

In asymptomatic patients, treatment can begin at any age 10, 20, 30). Usually, however, it is not necessary to begin treatment until a patient reaches 40, 50, 60 or Treatment typically entails multiple dosages over a period of time. Treatment can be monitored by assaying antibody, or activated T-cell or B-cell responses to the therapeutic agent Ag peptide) over time. If the response falls, a booster dosage is indicated. In the case of potential Down's syndrome patients, treatment can begin antenatally by administering therapeutic agent to the mother or shortly after birth.

IV. Treatment Regimes In prophylactic applications, pharmaceutical compositions or medicants are administered to a patient susceptible to, or otherwise at risk of, a particular disease in an amount sufficient to eliminate or reduce the risk or delay the outset of the disease. In therapeutic applications, compositions or medicants are administered to a patient suspected of, or already suffering from such a disease in an amount sufficient to cure, or at least partially arrest, the symptoms of the disease and its complications. An amount adequate to accomplish this is defined as a therapeutically- or pharmaceutically-effective dose. In both prophylactic and therapeutic regimes, agents are usually administered in several dosages until a sufficient immune response has been achieved. Typically, the immune response is monitored and Srepeated dosages are given if the immune response starts to fade.

IEffective doses of the compositions of the present IN invention, for the treatment of the above described conditions S 5 vary depending upon many different factors, including means of administration, target site, physiological state of the C patient, whether the patient is human or an animal, other 00 medications administered, and whether treatment is prophylactic or therapeutic. Usually, the patient is a human, but in some diseases, such as mad cow disease, the patient can Sbe a nonhuman mammal, such as a bovine. Treatment dosages need to be titrated to optimize safety and efficacy. The amount of immunogen depends on whether adjuvant is also administered, with higher dosages being required in the absence of adjuvant. The amount of an immunogen for administration sometimes varies from 1 pg-500 pg per patient and more usually from 5-500 pg per injection for human administration. Occasionally, a higher dose of 1-2 mg per injection is used. Typically about 10, 20, 50 or 100 pg is used for each human injection. The timing of injections can vary significantly from once a day, to once a year, to once a decade. On any given day that a dosage of immunogen is given, the dosage is greater than 1 pg/patient and usually greater than 10 pg/ patient if adjuvant is also administered, and greater than 10 pg/patient and usually greater than 100 Pg/patient in the absence of adjuvant. A typical regimen consists of an immunization followed by booster injections at 6 weekly intervals. Another regimen consists of an immunization followed by booster injections 1, 2 and 12 months later. Another regimen entails an injection every two months for life. Alternatively, booster injections can be on an irregular basis as indicated by monitoring of immune response.

For passive immunization with an antibody, the dosage ranges from about 0.0001 to 100 mg/kg, and more usually 0.01 to mg/kg of the host body weight. Doses for nucleic acids encoding immunogens range from about 10 ng to 1 g, 100 ng to 100 mg, 1 jg to 10 mg, or 30-300 pg DNA per patient. Doses for infectious viral vectors vary from 10-109, or more, virions per dose.

:Z Agents for inducing an immune response can be administered kQ by parenteral, topical, intravenous, oral, subcutaneous, intraperitoneal, intranasal or intramuscular means for prophylactic and/or therapeutic treatment. The most typical Ch route of administration is subcutaneous although others can be 00 equally effective. The next most common is intramuscular Sinjection. This type of injection is most typically performed in the arm or leg muscles. Intravenous injections as well as Sintraperitoneal injections, intraarterial, intracranial, or intradermal injections are also effective in generating an immune response. In some methods, agents are injected directly into a particular tissue where deposits have accumulated.

Agents of the invention can optionally be administered in combination with other agents that are at least partly effective in treatment of amyloidogenic disease. In the case of Alzheimer's and Down's syndrome, in which amyloid deposits occur in the brain, agents of the invention can also be administered in conjunction with other agents that increase passage of the agents of the invention across the blood-brain barrier.

Immunogenic agents of the invention, such as peptides, are sometimes administered in combination with an adjuvant. A variety of adjuvants can be used in combination with a peptide, such as A,3, to elicit an immune response. Preferred adjuvants augment the intrinsic response to an immunogen without causing conformational changes in the immunogen that affect the qualitative form of the response. Preferred adjuvants include alum, 3 De-O-acylated monophosphoryl lipid A (MPL) (see GB 2220211). QS21 is a triterpene glycoside or saponin isolated from the bark of the Quillaja Saponaria Molina tree found in South America (see Kensil et al., in Vaccine Design: The Subunit and Ajuvant Approach (eds. Powell Newman, Plenum Press, NY, 1995); US Patent No. 5,057,540).

Other adjuvants are oil in water emulsions (such as squalene or peanut oil), optionally in combination with immune stimulants, such as monophosphoryl lipid A (see Stoute et al., C-I N. Engl. J. Med. 336, 86-91 (1997)). Another adjuvant is CpG (Bioworld Today, Nov. 15, 1998). Alternatively, A/ can be coupled to an adjuvant. For example, a lipopeptide version of 0 5 A3 can be prepared by coupling palmitic acid or other lipids directly to the N-terminus of AP as described for hepatitis B C0 antigen vaccination (Livingston, J. Immunol. 159, 1383-1392 00 (1997)). However, such coupling should not substantially c-I change the conformation of A3 so as to affect the nature of CI 10 the immune response thereto. Adjuvants can be administered as Sa component of a therapeutic composition with an active agent or can be administered separately, before, concurrently with, or after administration of the therapeutic agent.

A preferred class of adjuvants is aluminum salts (alum), such as aluminum hydroxide, aluminum phosphate, aluminum sulfate. Such adjuvants can be used with or without other specific immunostimulating agents such as MPL or 3-DMP, QS21, polymeric or monomeric amino acids such as polyglutamic acid or polylysine. Another class of adjuvants is oil-in-water emulsion formulations. Such adjuvants can be used with or without other specific immunostimulating agents such as muramyl peptides N-acetylmuramyl-L-threonyl-Disoglutamine (thr-MDP), N-acetyl-normuramyl-L-alanyl-Disoglutamine (nor-MDP), N-acetylmuramyl-L-alanyl-Disoglutaminyl-L-alanine-2-(1'-2'dipalmitoyl-sn-glycero-3hydroxyphosphoryloxy)-ethylamine (MTP-PE), Nacetylglucsaminyl-N-acetylmuramyl-L-Al-D-isoglu-L-Aladipalmitoxy propylamide (DTP-DPP) theramideTM), or other bacterial cell wall components. Oil-in-water emulsions include MF59 (WO 90/14837), containing 5% Squalene, Tween 80, and 0.5% Span 85 (optionally containing various amounts of MTP-PE) formulated into submicron particles using a microfluidizer such as Model 110Y microfluidizer (Microfluidics, Newton MA), SAF, containing 10% Squalane, 0.4% Tween 80, 5% pluronic-blocked polymer L121, and thr-MDP, either microfluidized into a submicron emulsion or vortexed to generate a larger particle size emulsion, and Ribi

T

adjuvant system (RAS), (Ribi Immunochem, Hamilton, MT) Scontaining 2% squalene, 0.2% Tween 80, and one or more CI bacterial cell wall components from the group consisting of monophosphorylipid A (MPL), trehalose dimycolate (TDM), and cell wall skeleton (CWS), preferably MPL CWS (Detox

T

ID

5 Another class of preferred adjuvants is saponin adjuvants, such as Stimulon T (QS21, Aquila, Worcester, MA) or particles Ch generated therefrom such as ISCOMs (immunostimulating OO complexes) and ISCOMATRIX. Other adjuvants include Complete c- Freund's Adjuvant (CFA) and Incomplete Freund's Adjuvant Cl 10 (IFA). Other adjuvants include cytokines, such as interleukins (IL-1,IL-2, and IL-12), macrophage colony stimulating factor (M-CSF), tumor necrosis factor (TNF).

An adjuvant can be administered with an immunogen as a single composition, or can be administered before, concurrent with or after administration of the immunogen. Immunogen and adjuvant can be packaged and supplied in the same vial or can be packaged in separate vials and mixed before use. Immunogen and adjuvant are typically packaged with a label indicating the intended therapeutic application. If immunogen and adjuvant are packaged separately, the packaging typically includes instructions for mixing before use. The choice of an adjuvant and/or carrier depends on the stability of the vaccine containing the adjuvant, the route of administration, the dosing schedule, the efficacy of the adjuvant for the species being vaccinated, and, in humans, a pharmaceutically acceptable adjuvant is one that has been approved or is approvable for human administration by pertinent regulatory bodies. For example, Complete Freund's adjuvant is not suitable for human administration. Alum, MPL and QS21 are preferred. Optionally, two or more different adjuvants can be used simultaneously. Preferred combinations include alum with MPL, alum with QS21, MPL with QS21, and alum, QS21 and MPL together. Also, Incomplete Freund's ajuvant can be used (Chang et al., Advanced Drug Delivery Reviews 32, 173-186 (1998)), optionally in combination with any of alum, QS21, and MPL and all combinations thereof.

Agents of the invention are often administered as pharmaceutical compositions comprising an active therapeutic

ID

agent, and a variety of other pharmaceutically CI acceptable components. See Remington's Pharmaceutical Science ed., Mack Publishing Company, Easton, Pennsylvania, 1980). The preferred form depends on the intended mode of 0 5 administration and therapeutic application. The compositions can also include, depending on the formulation desired, CA pharmaceutically-acceptable, non-toxic carriers or diluents, OO which are defined as vehicles commonly used to formulate c- pharmaceutical compositions for animal or human CI 10 administration. The diluent is selected so as not to affect Sthe biological activity of the combination. Examples of such diluents are distilled water, physiological phosphate-buffered saline, Ringer's solutions, dextrose solution, and Hank's solution. In addition, the pharmaceutical composition or formulation may also include other carriers, adjuvants, or nontoxic, nontherapeutic, nonimmunogenic stabilizers and the like. However, some reagents suitable for administration to animals, such as Complete Freund's adjuvant are not typically included in compositions for human use.

Pharmaceutical compositions can also include large, slowly metabolized macromolecules such as proteins, polysaccharides, polylactic acids, polyglycolic acids and copolymers (such as latex functionalized sepharose, agarose, cellulose, and the like), polymeric amino acids, amino acid copolymers, and lipid aggregates (such as oil droplets or liposomes). Additionally, these carriers can function as immunostimulating agents adjuvants).

For parenteral administration, agents of the invention can be administered as injectable dosages of a solution or suspension of the substance in a physiologically acceptable diluent with a pharmaceutical carrier which can be a sterile liquid such as water oils, saline, glycerol, or ethanol.

Additionally, auxiliary substances, such as wetting or emulsifying agents, surfactants, pH buffering substances and the like can be present in compositions. Other components of pharmaceutical compositions are those of petroleum, animal, vegetable, or synthetic origin, for example, peanut oil, soybean oil, and mineral oil. In general, glycols such as propylene glycol or polyethylene glycol are preferred liquid OC carriers, particularly for injectable solutions.

STypically, compositions are prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for 0 5 solution in, or suspension in, liquid vehicles prior to injection can also be prepared. The preparation also can be C0 emulsified or encapsulated in liposomes or micro particles 00 such as polylactide, polyglycolide, or copolymer for enhanced 'q adjuvant effect, as discussed above (see Langer, Science 249, OC 10 1527 (1990) and Hanes, Advanced Drug Delivery Reviews 28, 97- S119 (1997). The agents of this invention can be administered in the form of a depot injection or implant preparation which can be formulated in such a manner as to permit a sustained or pulsatile release of the active ingredient.

Additional formulations suitable for other modes of administration include oral, intranasal, and pulmonary formulations, suppositories, and transdermal applications.

For suppositories, binders and carriers include, for example, polyalkylene glycols or triglycerides; such suppositories can be formed from mixtures containing the active ingredient in the range of 0.5% to 10%, preferably 1%- Oral formulations include excipients, such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, and magnesium carbonate. These compositions take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations or powders and contain 10%-95% of active ingredient, preferably 25%-70%.

Topical application can result in transdermal or intradermal delivery. Topical administration can be facilitated by co-administration of the agent with cholera toxin or detoxified derivatives or subunits thereof or other similar bacterial toxins (See Glenn et al., Nature 391, 851 (1998)). Co-administration can be achieved by using the components as a mixture or as linked molecules obtained by chemical crosslinking or expression as a fusion protein.

Alternatively, transdermal delivery can be achieved using a skin path or using transferosomes (Paul et al., Eur. J.

0 Immunol. 25, 3521-24 (1995); Cevc et al., Biochem. Biophys.

Acta 1368, 201-15 (1998)).

V. Methods of Diagnosis The invention provides methods of detecting an immune response against AO peptide in a patient suffering from or susceptible to Alzheimer's disease. The methods are OO particularly useful for monitoring a course of treatment being Sadministered to a patient. The methods can be used to monitor both therapeutic treatment on symptomatic patients and prophylactic treatment on asymptomatic patients.

iq Some methods entail determining a baseline value of an immune response in a patient before administering a dosage of agent, and comparing this with a value for the immune response after treatment. A significant increase greater than the typical margin of experimental error in repeat measurements of the same sample, expressed as one standard deviation from the mean of such measurments) in value of the immune response signals a positive treatment outcome that administration of the agent has achieved or augmented an immune response). If the value for immune response does not change significantly, or decreases, a negative treatment outcome is indicated. In general, patients undergoing an initial course of treatment with an agent are expected to show an increase in immune response with successive dosages, which eventually reaches a plateau. Administration of agent is generally continued while the immune response is increasing.

Attainment of the plateau is an indicator that the administered of treatment can be discontinued or reduced in dosage or frequency.

In other methods, a control value a mean and standard deviation) of immune response is determined for a control population. Typically the individuals in the control ponulation have not received prior treatment. Measured values of immune response in a patient after administering a therapeutic agent are then compared with the control value. A significant increase relative to the control value greater than one standard deviation from the mean) signals a positive treatment outcome. A lack of significant increase or I a decrease signals a negative treatment outcome.

Administration of agent is generally continued while the immune response is increasing relative to the control value.

As before, attainment of a plateau relative to control values in an indicator that the administration of treatment can be C discontinued or reduced in dosage or frequency.

OO In other methods, a control value of immune response c-I a mean and standard deviation) is determined from a control Ci 10 population of individuals who have undergone treatment with a Ctherapeutic agent and whose immune responses have plateaued in response to treatment. Measured values of immune response in a patient are compared with the control value. If the measured level in a patient is not significantly different more than one standard deviation) from the control value, treatment can be discontinued. If the level in a patient is significantly below the control value, continued administration of agent is warranted. If the level in the patient persists below the control value, then a change in treatment regime, for example, use of a different adjuvant may be indicated.

In other methods, a patient who is not presently receiving treatment but has undergone a previous course of treatment is monitored for immune response to determine whether a resumption of treatment is required. The measured value of immune response in the patient can be compared with a value of immune response previously achieved in the patient after a previous course of treatment. A significant decrease relative to the previous measurement greater than a typical margin of error in repeat measurements of the same sample) is an indication that treatment can be resumed. Alternatively, the value measured in patient can be compared with a control value (mean plus standard deviation) determined in population of patients after undergoing a course of treatment.

Alternatively, the measured value in a patient can be compared with a control value in populations of prophylactically treated patients who remain free of symptoms of disease, or populations of therapeutically treated patients who show amelioration of disease characteristics. In all of these CI cases, a significant decrease relative to the control level more than a standard deviation) is an indicator that treatment should be resumed in a patient.

0 5 The tissue sample for analysis is typically blood, plasma, serum, mucus or cerebral spinal fluid from the patient. The C0 sample is analyzed for indicia of an immune response to any OO form of Af peptide, typically A342. The immune response can cq- be determined from the presence of, antibodies or T- CI 10 cells that specifically bind to Af3 peptide. ELISA methods of Sdetecting antibodies specific to A3 are described in the Examples section. Methods of detecting reactive T-cells have been described above (see Definitions).

The invention further provides diagnostic kits for performing the diagnostic methods described above. Typically, such kits contain an agent that specifically binds to antibodies to A,3 or reacts with T-cells specific for A43. The kit can also include a label. For detection of antibodies to Aj3, the label is typically in the form of labelled antiidiotypic antibodies. For detection of antibodies, the agent can be supplied prebound to a solid phase, such as to the wells of a microtiter dish. For detection of reactive Tcells, the label can be supplied as 3 H-thymidine to measure a proliferative response. Kits also typically contain labelling providing directions for use of the kit. The labelling may also include a chart or other correspondence regime correlating levels of measured label with levels of antibodies to A8 or T-cells reactive with A3. The term labelling refers to any written or recorded material that is attached to, or otherwise accompanies a kit at any time during its manufacture, transport, sale or use. For example, the term labelling encompasses advertising leaflets and brochures, packaging materials, instructions, audio or video cassettes, computer discs, as well as writing imprinted directly on kits.

EXAMPLES

I. Prophylactic Efficacy of AQ Against AD 33 These examples describe administration of A042 peptide to transgenic mice overexpressing APP with a mutation at position 717 (APP717Vy-F) that predisposes them to develop Alzheimer's- IN like neuropathology. Production and characteristics of these mice (PDAPP mice) is described in Games et al., Nature, supra.

These animals, in their heterozygote form, begin to deposit A? C0 at six months of age forward. By fifteen months of age they 00 exhibit levels of A/ deposition equivalent to that seen in Alzheimer's disease. PDAPP mice were injected with aggregated

AS

42 (aggregated A/ 42 or phosphate buffered saline.

0 Aggregated A0 42 was chosen because of its ability to induce c-i antibodies to multiple epitopes of A0.

A. Methods 1. Source of Mice SThirty PDAPP heterogenic female mice were randomly divided into the following groups: 10 mice to be injected with 0 5 aggregated A0 42 (one died in transit), 5 mice to be injected with PBS/adjuvant or PBS, and 10 uninjected controls. Five Ch mice were injected with serum amyloid protein (SAP).

00 2. Preparation of Immunocens 0 Preparation of aggregated A6 42 two milligrams of A6 42

(US

0 10 Peptides Inc, lot K-42-12) was dissolved in 0.9 ml water and Smade up to 1 ml by adding 0.1 ml 10 x PBS. This was vortexed and allowed to incubate overnight 370 C, under which conditions the p.eptide aggregated. Any unused A0 was stored as a dry lyophilized powder at -200 C until the next injection.

3. Preparation of Injections 100 Mg of aggregated A1 4 2 in PBS per mouse was emulsified 1:1 with Complete Freund's adjuvant (CFA) in a final volume of 400 pl emulsion for the first immunization, followed by a boost of the same amount of immunogen in Incomplete Freund's adjuvant (IFA) at 2 weeks. Two additional doses in IFA were given at monthly intervals. The subsequent immunizations were done at monthly intervals in 500 Al of PBS. Injections were delivered intraperitoneally PBS injections followed the same schedule and mice were injected with a 1:1 mix of PBS/ Adjuvant at 400 il per mouse, or 500 Al of PBS per mouse. SAP injections likewise followed the same schedule using a dose of 100 Ag per injection.

4. Titration of Mouse Bleeds, Tissue Preparation and Immunohistochemistry The above methods are described infra in General Materials and Methods.

B. Results PDAPP mice were injected with either aggregated A8 42 (aggregated A0 42 SAP peptides, or phosphate buffered saline.

SA group of PDAPP mice were also left as uninjected, positive Cq controls. The titers of the mice to aggregated A4 4 2 were monitored every other month from the fourth boost until the mice were one year of age. Mice were sacrificed at 13 months.

At all time points examined, eight of the nine aggregated A6 42 mice developed a high antibody titer, which remained high throughout the series of injections (titers greater than 1/10000). The ninth mouse had a low, but measurable titer of 00 C<I approximately 1/1000 (Figure 1, Table SAPP-injected mice 10 had titers of 1:1,000 to 1:30,000 for this immunogen with only Sa single mice exceeding 1:10,0000.

SThe PBS-treated mice were titered against aggregated Af 42 at six, ten and twelve months. At a 1/100 dilution the PBS mice when titered against aggregated A0 42 only exceeded 4 times background at one data point, otherwise, they were less than 4 times background at all time points (Table The SAP-specific response was negligible at these time points with all titers less than 300.

Seven out of the nine mice in the aggregated Af1-42 group had no detectable amyloid in their brains. In contrast, brain tissue from mice in the SAP and PBS groups contained numerous 3D6-positive amyloid deposits in the hippocampus, as well as in the frontal and cingulate cortices. The pattern of deposition was similar to that of untreated controls, with characteristic involvement of vulnerable subregions, such as the outer molecular layer of the hippocampal dentate gyrus.

One mouse from the A,3 1-42-injected group had a greatly reduced amyloid burden, confined to the hippocampus. An isolated plaque was identified in another A3 1-42-treated mouse.

Quantitative image analyses of the amyloid burden in the hippocampus verified the dramatic reduction achieved in the AN1792-treated animals (Fig. The median values of the amyloid burden for the PBS group and for the untreated control group were significantly greater than for those immunized with AN1792 p=0.0005). In contrast, the median value for the group immunized with SAP peptides (SAPP) was 5.74%. Brain tissue from the untreated, control mice contained numerous AO amyloid deposits visualized CI with the Af-specific monoclonal antibody (mAb) 3D6 in the hippocampus, as well as in the retrosplenial cortex. A similar pattern of amyloid deposition was also seen in mice 0 5 immunized with SAPP or PBS (Fig. In addition, in these latter three groups there was a characteristic involvement of CA vulnerable subregions of the brain classically seen in AD, OO such as the outer molecular layer of the hippocampal dentate c- gyrus, in all three of these groups.

CI 10 The brains that contained no AO deposits were also devoid Sof neuritic plaques that are typically visualized in PDAPP mice with the human APP antibody 8E5. All of brains from the remaining groups (SAP-injected, PBS and uninjected mice) had numerous neuritic plaques typical of untreated PDAPP mice. A small number of neuritic plaques were present in one mouse treated with AN1792, and a single cluster of dystrophic neurites was found in a second mouse treated with AN1792.

Image analyses of the hippocampus, and shown in Fig. 3, demonstrated the virtual elimination of dystrophic neurites in AN1792-treated mice (median 0.00%) compared to the PBS recipients (median 0.28%, p 0.0005).

Astrocytosis characteristic of plaque-associated inflammation was also absent in the brains of the A01-42 injected group. The brains from the mice in the other groups contained abundant and clustered GFAP-positive astrocytes typical of AO plaque-associated gliosis. A subset of the GFAP-reacted slides were counter-stained with Thioflavin S to localize the A,6 deposits. The GFAP-positive astrocytes were associated with Aj plaques in the SAP, PBS and untreated controls. No such association was found in the plaque-negative A1-42 treated mice, while minimal plaque-associated gliosis was identified in one mouse treated with AN1792.

Image analyses, shown in Fig. 4 for the retrosplenial cortex, verified that the reduction in astrocytosis was significant with a median value of 1.56% for those treated with AN1792 versus median values greater than 6% for groups immunized with SAP peptides, PBS or untreated (p=0.0017) Evidence from a subset of the A 1-42- and PBS-injected mice indicated plaque-associated MHC II immunoreactivity was absent in the A01-42 injected mice, consistent with lack of an IND A3-related inflammatory response.

0 5 Sections of the mouse brains were also reacted with a mA3 specific for MAC-1, a cell surface protein. MAC-1 (CD11b) is Ch an integrin family member and exists as a heterodimer with 00 CD18. The CD11b/CD18 complex is present on monocytes, macrophages, neutrophils and natural killer cells (Mak and c 10 Simard). The resident MAC-1-reactive cell type in the brain Sis likely to be microglia based on similar phenotypic rC morphology in MAC-1 immunoreacted sections. Plaque-associated MAC-1 labeling was lower in the brains of mice treated with AN1792 compared to the PBS control group, a finding consistent with the lack of an AO-induced inflammatory response.

C. Conclusion The lack of A3 plaques and reactive neuronal and gliotic changes in the brains of the A3l-42-injected mice indicate that no or extremely little amyloid was deposited in their brains, and pathological consequences, such as gliosis and neuritic pathology, were absent. PDAPP mice treated with A41-42 show essentially the same lack of pathology as control nontransgenic mice. Therefore, A41-42 injections are highly effective in the prevention of deposition or clearance of human A3 from brain tissue, and elimination of subsequent neuronal and inflammatory degenerative changes. Thus, administration of A3 peptide has therapeutic benefit in prevention of AD.

II. Dose Response Study Groups of five-week old, female Swiss Webster mice (N=6 per group) were immunized with 300, 100, 33, 11, 3.7, 1.2, 0.4, or 0.13 ug of A, formulated in CFA/IFA administered intraperitoneally. Three doses were given at biweekly intervals followed by a fourth dose one month later. The first dose was emulsified with CFA and the remaining doses were emulsified with IFA. Animals were bled 4-7 days

I

C following each immunization starting after the second dose c-i for measurement of antibody titers. Animals in a subset of three groups, those immunized with 11, 33, or 300 pg of antigen, were additionally bled at approximately monthly intervals for four months following the fourth immunization to monitor the decay of the antibody response across a range of vaccine doses. These animals received a final fifth immunization at seven months after study initiation. They o00 A were sacrificed one week later to measure antibody responses c- 10 to AN1792 and to perform toxicological analyses.

ND A declining dose response was observed from 300 to 3.7 pg Swith no response at the two lowest doses. Mean antibody titers are about 1:1000 after 3 doses and about 1:10,000 after 4 doses of 11-300 pg of antigen (see Fig. Antibody titers rose dramatically for all but the lowest dose group following the third immunization with increases in GMTs ranging from 5- to 25-fold. Low antibody responses were then detectable for even the 0.4 pg recipients. The 1.2 and 3.7 pg groups had comparable titers with GMTs of about 1000 and the highest four doses clustered together with GMTs of about 25,'000, with the exception of the 33 pg dose group with a lower GMT of 3000. Following the fourth immunization, the titer increase was more modest for most groups. There was a clear dose response across the lower antigen dose groups from 0.14 pg to 11 pg ranging from no detectable antibody for recipients of 0.14 pg to a GMT of 36,000 for recipients of 11 jg. Again, titers for the four highest dose groups of 11 to 300 pg clustered together. Thus following two immunizations, the antibody titer was dependent on the antigen dose across the broad range from 0.4 to 300 pg. By the third immunization, titers of the highest four doses were all comparable and they remained at a plateau after an additional immunization.

One month following the fourth immunization, titers were 2to 3-fold higher in the 300 pg group than those measured from blood drawn five days following the immunization (Fig. 6).

This observation suggests that the peak anamnestic antibody response occurred later than 5 days post-immunization. A more modest increase was seen at this time in the 33 jig group. In the 300 gg dose group at two months following the last dose, GMTs declined steeply by about 70%. After another IN month, the decline was less steep at 45% (100 Ag) and about 0 5 14% for the 33 and 11 ig doses. Thus, the rate of decline in circulating antibody titers following cessation of O immunization appears to be biphasic with a steep decline the 00 first month following peak response followed by a more modest Srate of decrease thereafter.

The antibody titers and the kinetics of the response of Sthese Swiss Webster mice are similar to those of young c- heterozygous PDAPP transgenic mice immunized in a parallel manner. Dosages effective to induce an immune response in humans are typically similar to dosages effective in mice.

III. Screen For Therapeutic Efficacy Against Established AD This assay is designed to test immunogenic agents for activity in arresting or reversing neuropathological characteristics of AD in aged animals. Immunizations with 42 amino acid long A8 (AN1792) were begun at a timepoint when amyloid plaques are already present in the brains of the PDAPP mice.

Over the timecourse used in this study, untreated PDAPP mice develop a number of neurodegenerative changes that resemble those found in AD (Games et al., supra and Johnson- Wood et al., Proc. Natl. Acad. Sci. USA 94, 1550-1555 (1997)).

The deposition of Af3 into amyloid plaques is associated with a degenerative neuronal response consisting of aberrant axonal and dendritic elements, called dystrophic neurites. Amyloid deposits that are surrounded by and contain dystrophic neurites called neuritic plaques. In both AD and the PDAPP mouse, dystrophic neurites have a distinctive globular structure, are immunoreactive with a panel of antibodies recognizing APP and cytoskeletal components, and display complex subcellular degenerative changes at the ultrastructural level. These characteristics allow for disease-relevant, selective and reproducible measurements of neuritic plaque formation in the PDAPP brains. The dystrophic 0 neuronal component of PDAPP neuritic plaques is easily CI visualized with an antibody specific for human APP (mAf3 Sand is readily measurable by computer-assisted image analysis.

-n s Therefore, in addition to measuring the effects of AN1792 on 5 amyloid plaque formation, we monitored the effects of this treatment on the development of neuritic dystrophy.

Ch Astrocytes and microglia are non-neuronal cells that OO respond to and reflect the degree of neuronal injury. GFAPc positive astrocytes and MHC II-positive microglia are commonly Cl 10 observed in AD, and their activation increases with the Sseverity of the disease. Therefore, we also monitored the development of reactive astrocytosis and microgliosis in the AN1792-treated mice.

A. Materials and Methods Forty-eight, heterozygous female PDAPP mice, 11 to 11.5 months of age, obtained from Charles River, were randomly divided into two groups: 24 mice to be immunized with 100 pg of AN1792 and 24 mice to be immunized with PBS, each combined with Freund's adjuvant. The AN1792 and PBS groups were again divided when they reached -15 months of age. At 15 months of age approximately half of each group of the AN1792- and PBStreated animals were euthanized (n=10 and 9, respectively), the remainder continued to receive immunizations until termination at -18 months (n=9 and 12, respectively). A total of.8 animals (5 AN1792, 3 PBS) died during the study. In addition to the immunized animals, one-year old month old (n=10) and 18-month old (n=10) untreated PDAPP mice were included for comparison in the ELISAs to measure a3 and APP levels in the brain; the one-year old animals were also included in the immunohistochemical analyses.

Methodology was as in Example 1 unless otherwise indicated.

US Peptides lot 12 and California Peptides lot ME0339 of AN1792 were used to prepare the antigen for the six immunizations administered prior to the 15-mont.h timepoint.

California Peptides lots ME0339 and ME0439 were used for the three additional immunizations administered between 15 and 18 months.

For immunizations, 100 pg of AN1792 in 200 pl PBS or PBS C1 alone was emulsified 1:1 (vol:vol) with Complete Freund's adjuvant (CFA) or Incomplete Freund's adjuvant (IFA) or PBS in a final volume of 400 pl. The first immunization was 0 5 delivered with CFA as adjuvant, the next four doses were given with IFA and the final four doses with PBS alone without added C0 adjuvant. A total of nine immunizations were given over the 00 seven-month period on a two-week schedule for the first three c q) doses followed by a four-week interval for the remaining CI 10 injections. The four-month treatment group, euthanized at Smonths of age, received only the first 6 immunizations.

B. Results 1. Effects of AN1792 Treatment on Amyloid Burden The results of AN1792 treatment on cortical amyloid burden determined by quantitative image analysis are shown in Fig. 7.

The median value of cortical amyloid burden was 0.28% in a group of untreated 12-month old PDAPP mice, a value representative of the plaque load in mice at the study's initiation. At 18 months, the amyloid burden increased over 17-fold to 4.87% in PBS-treated mice, while AN1792-treated mice had a greatly reduced amyloid burden of only 0.01%, notably less than the 12-month untreated and both the 15- and 18-month PBS-treated groups. The amyloid burden was significantly reduced in the AN1792 recipients at both 15 (96% reduction; p=0.003) and 18 reduction; p=0.0002) months.

Typically, cortical amyloid deposition in PDAPP mice initiates in the frontal and retrosplenial cortices (RSC) and progresses in a ventral-lateral direction to involve the temporal and entorhinal cortices Little or no amyloid was found in the EC of 12 month-old mice, the approximate age at which AN1792 was first administered. After 4 months of AN1792 treatment, amyloid deposition was greatly diminished in the RSC, and the progressive involvement of the EC was entirely eliminated by AN1792 treatment. The latter observation showed that AN1792 completely halted the progression of amyloid that would normally invade the temporal 0 and ventral cortices, as well as arrested or possibly reversed c-q deposition in the RSC.

The profound effects of AN1792 treatment on developing cortical amyloid burden in the PDAPP mice are further demonstrated by the 18-month group, which had been treated for seven months. A near complete absence of cortical amyloid was found in the AN1792-treated mouse, with a total lack of diffuse plaques, as well as a reduction in compacted deposits.

00 2. AN1792 Treatment-associated Cellular and Morphological D 10 Changes A population of AO-positive cells was found in brain C regions that typically contain amyloid deposits. Remarkably, in several brains from AN1792 recipients, very few or no extracellular cortical amyloid plaques were found. Most of the A3 immunoreactivity appeared to be contained within cells with large lobular or clumped soma. Phenotypically, these cells resembled activated microglia or monocytes. They were immunoreactive with antibodies recognizing ligands expressed by activated monocytes and microglia (MHC II and CD11b) and were occasionally associated with the wall or lumen of blood vessels. Comparison of near-adjacent sections labeled with A/ and MHC II-specific antibodies revealed that similar patterns of these cells were recognized by both classes of antibodies.

Detailed examination of the AN1792-treated brains revealed that the MHC II-positive cells were restricted to the vicinity of the limited amyloid remaining in these animals. Under the fixation conditions employed, the cells were not immunoreactive with antibodies that recognize T cell (CD3, CD3e) or B cell (CD45RA, CD45RB) ligands or leukocyte common antigen (CD45), but were reactive with an antibody recognizing leukosialin (CD43) which cross-reacts with monocytes. No such cells were found in any of the PBS-treated mice.

PDAPP mice invariably develop heavy amyloid deposition in the outer molecular layer of the hippocampal dentate gyrus.

The deposition forms a distinct streak within the perforant pathway, a subregion that classically contains amyloid plaques in AD. The characteristic appearance of these deposits in PBS-treated mice resembled that previously characterized in Suntreated PDAPP mice. The amyloid deposition consisted of C< both diffuse and compacted plaques in a continuous band. In contrast, in a number of brains from AN1792-treated mice this pattern was drastically altered. The hippocampal amyloid C 5 deposition no longer contained diffuse amyloid, and the banded pattern was completely disrupted. Instead, a number of unusual punctate structures were present that are reactive ~Q with anti-A3 antibodies, several of which appeared to be 00 CI amyloid-containing cells.

10 MHC II-positive cells were frequently observed in the Svicinity of extracellular amyloid in AN1792-treated animals.

The pattern of association of A/-positive cells with amyloid was very similar in several brains from AN1792-treated mice.

The distribution of these monocytic cells was restricted to the proximity of the deposited amyloid and was entirely absent from other brain regions devoid of A3 plaques.

Quantitative image analysis of MHC II and MAC I-labeled sections revealed a trend towards increased immunoreactivity in the RSC and hippocampus of AN1792-treated mice compared to the PBS group.which reached significance with the measure of MAC 1 reactivity in hippocampus.

These results are indicative of active, cell-mediated removal of amyloid in plaque-bearing brain regions.

3. AN1792 Effects on AR Levels: ELISA Determinations Cortical Levels In untreated PDAPP mice, the median level of total Af3 in the cortex at 12 months was 1,600 ng/g, which increased to 8,700 ng/g by 15 months (Table At 18 months the value was 22,000 ng/g, an increase of over 10-fold during the time course of the experiment. PBS-treated animals had 8,600 ng/g total A at 15 months which increased to 19,000 ng/g at 18 months. In contrast, AN1792-treated animals had 81% less total A3 at 15 months (1,600 ng/g) than the PBS-immunized group. Significantly less (p=0.0001) total Af3 (5,200 ng/g) was found at 18 months when the AN1792 and PBS groups were compared (Table representing a 72% reduction in the A,3 that would otherwise be present. Similar results were obtained when cortical levels of A042 were compared, namely that the AN1792-treated group contained much less A342, but in this case the differences between the AN1792 and PBS groups were significant at both 15 months (p=0.04) and 18 months (p=0.0001, Table 2).

Table 2: Median Af Levels (ng/g) in Cortex UNTREATED PBS AN1792 O C° 0 1 o z

O

(N4 ,0 Age Total A# A/42 Total Af A042 Total A$42 (n) 12 1,600 1,300 15 8,700 8,300 (10) 8,600 7,200 1,600 1.300' 18 22,200 18,500 (10) 19,000 15.900 (12) 5,200" 4,000"" (9) *p 0.0412 p 0.0001 Hippocamoal Levels In untreated PDAPP mice, median hippocampal levels of total A3 at twelve months of age were 15,000 ng/g which increased to 51,000 ng/g at 15 months and further to 81,000 ng/g at 18 months (Table Similarly, PBS immunized mice showed values of 40,000 ng/g and 65,000 ng/g at 15 months and 18 months, respectively. AN1792 immunized animals exhibited less total A3, specifically 25,000 ng/g and 51,000 ng/g at the respective 15-month and 18-month timepoints. The 18-month AN1792-treated group value was significantly lower than that of the PBS treated group 0.0105; Table Measurement of A042 gave the same pattern of results, namely that levels in the AN1792-treated group were significantly lower than in the PBS group (39,000 ng/g vs. 57,000 ng/g, respectively; p=0.00 22 at the 18-month evaluation (Table 3).

Table 3: Median Al Levels (ng/g) in Hippocampus UNTREATED PBS AN1792 Age Total A0 A042 Total A3 A342 Total A342 (n) 12 15,500 11,100 15 51,500 44,400 (10) 40,100 35,700 24,500 22,100 18 80,800 64,200 (10) 65,400 57,100 (12) 50,900' 38,900"' (9) 0

NO

MD

0 5 p 0.0105 p 0.0022 Cerebellar Levels In 12-month untreated PDAPP mice, the median cerebellar level of total A/ was 15 ng/g (Table At 15 months, this median increased to 28 ng/g and by 18 months had risen to ng/g. PBS-treated animals displayed median total A3 values of 21 ng/g at 15 months and 43 ng/g at 18 months. AN1792-treated animals were found to have 22 ng/g total A8 at 15 months and significantly less (p=0.

0 0 2 total A3 at 18 months (25 ng/g) than the corresponding PBS group (Table 4).

Table 4: Median Al Levels (ng/g) in Cerebellum UNTREATED PBS AN1792 Age (months) Total A# Total A$ Total A# (n) 12 15.6 27.7 (10) 20.8 21.7 18 35.0 (10) 43.1 (12) 24.8' (9) *p 0.0018 4. Effects of AN1792 Treatment on APP Levels APP-a and the full-length APP molecule both contain all or part of the A3 sequence and thus could be potentially impacted by the generation of an AN1792-directed immune response. In studies to date, a slight increase in APP levels has been noted as neuropathology increases in the PDAPP mouse. In the cortex, levels of either APP-a/FL (full length) or APP-a were essentially unchanged by treatment with the exception that APP-a was reduced by 19% at the 18-month timepoint in the AN1792-treated vs. the PBS-treated group. The 18-month AN1792-treated APP values were not significantly different from values of the 12-month and 15-month untreated and OC month PBS groups. In all cases the APP values remained within the ranges that are normally found in PDAPP mice.

0 5. Effects of AN1792 Treatment on Neurodegenerative and Gliotic Patholory Neuritic plaque burden was significantly reduced in the C0 frontal cortex of AN1792-treated mice compared to the PBS 00 CO group at both 15 p=0.03) and 18 p=0.01) months of age (Fig. The median value of the neuritic plaque burden increased from 0.32% to 0.49% in the PBS group between 15 and S18 months of age. This contrasted with the greatly reduced development of neuritic plaques in the AN1792 group, with median neuritic plaque burden values of 0.05% and 0.22%, in the 15 and 18 month groups, respectively.

Immunizations with AN1792 seemed well tolerated and reactive astrocytosis was also significantly reduced in the RSC of AN1792-treated mice when compared to the PBS group at both 15 p=0.011) and 18 p=0.028) months of age (Fig. Median values of the percent of astrocytosis in the PBS group increased between 15 and 18 months from 4.26% to 5.21%. AN1792-treatment suppressed the development of astrocytosis at both time points to 1.89% and 3.2%, respectively. This suggests the neuropil was not being damaged by the clearance process.

6. Antibody Responses As described above, eleven-month old, heterozygous PDAPP mice (N=24) received a series of 5 immunizations of 100 ig of AN1792 emulsified with Freund's adjuvant and administered intraperitoneally at weeks 0, 2, 4, 8, and 12, and a sixth immunization with PBS alone (no Freund's adjuvant) at week 16.

As a negative control, a parallel set of 24 age-matched transgenic mice received immunizations of PBS emulsified with the same adjuvants and delivered on the same schedule.

Animals were bled within three to seven days following each immunization starting after the second dose. Antibody responses to AN1792 were measured by ELISA. Geometric mean titers (GMT) for the animals that were immunized with AN1792 were approximately 1,900, 7,600, and 45,000 following the C< second, third and last (sixth) doses respectively. No A43- 'specific antibody was measured in control animals following the sixth immunization.

0 5 Approximately one-half of the animals were treated for an additional three months, receiving immunizations at about C0 24 and 27 weeks. Each of these doses was delivered in PBS 0O vehicle alone without Freund's adjuvant. Mean antibody titers 09 remained unchanged over this time period. In fact, antibody CI 10 titers appeared to remain stable from the fourth to the eighth Sbleed corresponding to a period covering the fifth to the pi ninth injections.

To determine if the Ao-specific antibodies elicited by immunization that were detected in the sera of AN1792-treated mice were also associated with deposited brain amyloid, a subset of sections from the AN1792- and PBS-treated mice were reacted with an antibody specific for mouse IgG. In contrast to the PBS group, A3 plaques in AN1792-treated brains were coated with endogenous IgG. This difference between the two groups was seen in both 15-and 18-month groups. Particularly striking was the lack of labeling in the PBS group, despite the presence of a heavy amyloid burden in these mice. These results show that immunization with a synthetic A protein generates antibodies that recognize and bind in vivo to the A43 in amyloid plaques.

7. Cellular-Mediated Immune Responses Spleens were removed from nine AN1792-immunized and 12 PBS-immunized 18-month old PDAPP mice 7 days after the ninth immunization. Splenocytes were isolated and cultured for 72 h in the presence of A,640, A,642, or A340-1 (reverse order protein). The mitogen Con A served as a positive control.

Optimum responses were obtained with >1.7 pM protein. Cells from all nine AN1792-treated animals proliferated in response.

to either A,31-40 or A13-42 protein, with equal levels of incorporation for both proteins (Fig. 10, Upper Panel) There was no response to the A040-1 reverse protein. Cells from v control animals did not respond to any of the A3 proteins CI (Fig. 10, Lower Panel).

C. Conclusion SThe results of this study show that AN1792 immunization of PDAPP mice possessing existing amyloid deposits slows and 0\ prevents progressive amyloid deposition and retard OO consequential neuropathological changes in the aged PDAPP 0c mouse brain. Immunizations with AN1792 essentially halted C' amyloid developing in structures that would normally succumb to amyloidosis. Thus, administration of A3 peptide has Stherapeutic benefit in the treatment of AD.

IV. Screen of A3 Fragments 100 PDAPP mice age 9-11 months are immunized with 9 different regions of APP and A3 to determine which epitopes convey the response. The 9 different immunogens and one control are injected i.p. as described above. The immunogens include four human A3 peptide conjugates 1-12, 13-28, 32-42, all coupled to sheep anti-mouse IgG via a cystine link; an APP polypeptide aa 592-695, aggregated human A 1-40, and aggregated human A 25-35, and aggregated rodent A842.

Aggregated A042 and PBS are used as controls. Ten mice are used per treatment group. Titers are monitored as above and mice are euthanized at the end of 4 months of injections.

Histochemistry, A3 levels, and toxicology are determined post mortem.

A. Materials and Methods 1. Preparation of Immunogens Preparation of coupled A3 peptides: four human A0 peptide conjugates (amino acid residues 1-5, 1-12, 13-28, and 33-42, each conjugated to sheep anti-mouse IgG) were prepared by coupling through an artificial cysteine added to the A3 peptide using the crosslinking reagent sulfo-EMCS. The A peptide derivatives were synthesized with the following final amino acid sequences. In each case, the location of the inserted cysteine residue is indicated by underlining. The

ID

SA613-28 peptide derivative also had two glycine residues added CI prior to the carboxyl terminal cysteine as indicated.

SA31-12 peptide NH 2 -DAEFRHDSGYEVC COOH A01-5 peptide NH 2 -DAEFRC COOH A033-42 peptide NH 2 -C-amino-heotanoic acid-GLMVGGVVIA COOH a A013-28 peptide Ac-NH-HHQKLVFFAEDVGSNKGGC-COOH 00 0c To prepare for the coupling reaction, ten mg of sheep CI anti-mouse IgG (Jackson ImmunoResearch Laboratories) was Sdialyzed overnight against 10 mM sodium borate buffer, pH The dialyzed antibody was then concentrated to a volume of 2 mL using an Amicon Centriprep tube. Ten mg sulfo-EMCS (N (e-maleimidocuproyloxy) succinimide] (Molecular Sciences Co.) was dissolved in one mL deionized water. A 40-fold molar excess of sulfo-EMCS was added dropwise with stirring to the sheep anti-mouse IgG and then the solution was stirred for an additional ten min. The activated sheep anti-mouse IgG was purified and buffer exchanged by passage over a 10 mL gel filtration column (Pierce Presto Column, obtained from Pierce Chemicals) equilibrated with 0.1 M NaPO 4 0 5 mM EDTA, pH Antibody containing fractions, identified by absorbance at 280 nm, were pooled and diluted to a concentration of approximately 1 mg/mL, using 1.4 mg per OD as the extinction coefficient. A 40-fold molar excess of A$3 peptide was dissolved in 20 mL of 10 mM NaP0 4 pH 8.0, with the exception of the A333-42 peptide for which 10 mg was first dissolved in mL of DMSO and then diluted to 20 mL with the 10 mM NaPO 4 buffer. The peptide solutions were each added to 10 mL of activated sheep anti-mouse IgG and rocked at room temperature for 4 hr. The resulting conjugates were concentrated to a final volume of less than 10 mL using an Amicon Centriprep tube and then dialyzed against PBS to buffer exchange the buffer and remove free peptide. The conjugates were passed through 0.22 x-pore size filters for sterilization and then aliquoted into fractions of 1 mg and stored frozen at -20 0

C.

The concentrations of the conjugates were determined using the BCA protein assay (Pierce Chemicals) with horse IgG for the 0 standard curve. Conjugation was documented by the molecular c- weight increase of the conjugated peptides relative to that of the activated sheep anti-mouse IgG. The A, 1-5 sheep antimouse conjugate was a pool of two conjugations, the rest were from a single preparation.

2. Preparation of aggregated A6 peptides Human 1-40 (AN1528; California Peptides Inc., Lot ME0541), 00 C< human 1-42 (AN1792; California Peptides Inc., Lots ME0339 and eCq ME0439), human 25-35, and rodent 1-42 (California Peptides Inc., Lot ME0218) peptides were freshly solubilized for the Spreparation of each set of injections from lyophilized powders that had been stored desiccated at -20 0 For this purpose, two mg of peptide were added to 0.9 ml of deionized water and the mixture was vortexed to generate a relatively uniform solution or suspension. Of the four, AN1528 was the only peptide soluble at this step. A 100 pl aliquot of 10X PBS (IX PBS: 0.15 M NaCl, 0.01 M sodium phosphate, pH 7.5) was then added at which point AN1528 began to precipitate. The suspension was vortexed again and incubated overnight at 37*C for use the next day.

Preparation of the pBx6 protein: An expression plasmid encoding pBx6, a fusion protein consisting of the 100-amino acid bacteriophage MS-2 polymerase N-terminal leader sequence followed by amino acids 592-695 of APP (APP) was constructed as described by Oltersdorf et al., J. Biol. Chem. 265, 4492- 4497 (1990). The plasmid was transfected into E. coli and the protein was expressed after induction of the promoter. The bacteria were lysed in 8M urea and pBx6 was partially purified by preparative SDS PAGE. Fractions containing pBx6 were identified by Western blot using a rabbit anti-pBx6 polyclonal antibody, pooled, concentrated using an Amicon Centriprep tube and dialysed against PBS. The purity of the preparation, estimated by Coomassie Blue stained SDS PAGE, was approximately 5 to B. Results and Discussion C- 1. Study Design One hundred male and female, nine- to eleven-month old heterozygous PDAPP transgenic mice were obtained from Charles 0 5 River Laboratory and Taconic Laboratory. The mice were sorted into ten groups to be immunized with different regions of A,8 C0 or APP combined with Freund's adjuvant. Animals were O distributed to match the gender, age, parentage and source of c the animals within the groups as closely as possible. The Ci 10 immunogens included four A3 peptides derived from the human Ssequence, 1-5, 1-12, 13-28, and 33-42, each conjugated to sheep anti-mouse IgG; four aggregated A43 peptides, human 1-40 (AN1528), human 1-42 (AN1792), human 25-35, and rodent 1-42; and a fusion polypeptide, designated as pBx6, containing APP amino acid residues 592-695. A tenth group was immunized with PBS combined with adjuvant as a control.

For each immunization, 100 gg of each A46 peptide in 200 pl PBS or 200 Ag of the APP derivative pBx6 in the same volume of PBS or PBS alone was emulsified 1:1 (vol:vol) with Complete Freund's adjuvant (CFA) in a final volume of 400 pl for the first immunization, followed by a boost of the same amount of immunogen in Incomplete Freund's adjuvant (IFA) for the subsequent four doses and with PBS for the final dose.

Immunizations were delivered intraperitoneally on a biweekly schedule for the first three doses, then on a monthly schedule thereafter. Animals were bled four to seven days following each immunization starting after the second dose for the measurement of antibody titers. Animals were euthanized approximately one week after the final dose.

2. A0 and APP Levels in the Brain Following about four months of immunization with the various A0 peptides or the APP derivative, brains were removed from saline-perfused animals. One hemisphere was prepared for immunohistochemical analysis and the second was used for the quantitation of A0 and APP levels. To measure the concentrations of various forms of beta amyloid peptide and amyloid precursor protein, the hemisphere was dissected and 0 homogenates of the hippocampal, cortical, and cerebellar regions were prepared in 5 M guanidine. -These were diluted and the level of amyloid or APP was quantitated by comparison to a series of dilutions of standards of A3 peptide or APP of known concentrations in an ELISA format.

The median concentration of total A3 for the control group immunized with PBS was 5.8-fold higher in the hippocampus than Cin the cortex (median of 24,318 ng/g hippocampal tissue 00 compared to 4,221 ng/g for the cortex). The median level in the cerebellum of the control group (23.4 ng/g tissue) was IND about 1,000-fold lower than in the hippocampus. These levels Sare similar to those that we have previously reported for heterozygous PDAPP transgenic mice of this age (Johnson-Woods et al., 1997, supra).

For the cortex, a subset of treatment groups had median total A0 and A31-42 levels which differed significantly from those of the control group (p 0.05), those animals receiving AN1792, rodent A81-42 or the A$31-5 peptide conjugate as shown in Fig. 11. The median levels of total A3 were reduced by 75%, 79% and 61%, respectively, compared to the control for these treatment groups. There were no discernable correlations between A13-specific antibody titers and A3 levels in the cortical region of the brain for any of the groups.

In the hippocampus, the median reduction of total A0 associated with AN1792 treatment p 0.0543) was not as great as that observed in the cortex p 0.0021).

However, the magnitude of the reduction was far greater in the hippocampus than in the cortex, a net reduction of 11,186 ng/g tissue in the hippocampus versus 3,171 ng/g tissue in the cortex. For groups of animals receiving rodent Al1-42 or the median total A,3 levels were reduced by 36% and 26%, respectively. However, given the small group sizes and the high variability of the amyloid peptide levels from animal to animal within both groups, these reductions were not significant. When the levels of A,1-42 were measured in the hippocampus, none of the treatment-induced reductions reached significance. Thus, due to the smaller A3 burden in the cortex, changes in this region are a more sensitive indicator 0 of treatment effects. The changes in A3 levels measured by c- ELISA in the cortex are similar, but not identical, to the results from the immunohistochemical analysis (see below) Total A was also measured in the cerebellum, a region D 5 typically unaffected in the AD pathology. None of the median AO concentrations of any of the groups immunized with the Ch various AO peptides or the APP derivative differed from that CA of the control group in this region of the brain. This result C<i suggests that non-pathological levels of AO are unaffected by 10 treatment.

ND APP concentration was also determined by ELISA in the Scortex and cerebellum from treated and control mice. Two different APP assays were utilized. The first, designated APP-a/FL, recognizes both APP-alpha the secreted form of APP which has been cleaved within the A sequence), and fulllength forms (FL) of APP, while the second recognizes only APP-a. In contrast to the treatment-associated diminution of A,3 in a subset of treatment groups, the levels of APP were unchanged in all of the treated compared to the control animals. These results indicate that the immunizations with A43 peptides are not depleting APP; rather the treatment effect is specific to A3.

In summary, total A3 and A,1-42 levels were significantly reduced in the cortex by treatment with AN1792, rodent A$,1-42 or A13l-5 conjugate. In the hippocampus, total A3 was significantly reduced only by AN1792 treatment. No other treatment-associated changes in A3 or APP levels in the hippocampal, cortical or cerebellar regions were significant.

2. Histochemical Analyses Brains from a subset of six groups were prepared for immunohistochemical analysis, three groups immunized with the A3 peptide conjugates Al1-5, Al1-12, and A313-28; two groups immunized with the full length AO aggregates AN1792 and AN1528 and the PBS-treated control group. The results of image analyses of the amyloid burden in brain sections from these groups are shown in Fig. 12. There were significant reductions of amyloid burden in the cortical regions of three of the treatment groups versus control animals. The greatest reduction of amyloid burden was observed in the group receiving AN1792 where the mean value was reduced by 97% (p 0.001). Significant reductions were also observed for those C 5 animals treated with AN1528 p 0.005) and the peptide conjugate p 0.02).

The results obtained by quantitation of total Af3 or A,1-42 C0 by ELISA and amyloid burden by image analysis differ to some 0, extent. Treatment with AN1528 had a significant impact on the level of cortical amyloid burden when measured by quantitative IN image analysis but not on the concentration of total Af3 in the same region when measured by ELISA. The difference between these two results is likely to be due to the specificities of the assays. Image analysis measures only insoluble A,6 aggregated into plaques. In contrast, the ELISA measures all forms of A3, both soluble and insoluble, monomeric and aggregated. Since the disease pathology is thought to be associated with the insoluble plaque-associated form of Af, the image analysis technique may have more sensitivity to reveal treatment effects. However since the ELISA is a more rapid and easier assay, it is very useful for screening purposes. Moreover it may reveal that the treatmentassociated reduction of Af3 is greater for plaque-associated than total A8.

To determine if the A13-specific antibodies elicited by immunization in the treated animals reacted with deposited brain amyloid, a subset of the sections from the treated animals and the control mice were reacted with an antibody specific for mouse IgG. In contrast to the PBS group, A8containing plaques were coated with endogenous IgG for animals immunized with the A43 peptide conjugates A01l-5, A1-12, and A13-28; and the full length A aggregates AN1792 and AN1528.

Brains from animals immunized with the other A0 peptides or the APP peptide pBx6 were not analyzed by this assay.

3. Measurement of Antibody Titers Mice were bled four to seven days following each immunization starting after the second immunization, for a Stotal of five bleeds. Antibody titers were measured as A31- 42-binding antibody using a sandwich ELISA with plastic multiwell plates coated with A01-42. As shown in Fig. 13, peak -s antibody titers were elicited following the fourth dose for N 5 those four vaccines which elicited the highest titers of AN1792-specific antibodies: AN1792 (peak GMT: 94,647), AN1528 (peak GMT: 88,231), A01-12 conjugate (peak GMT: 47,216)and Ch rodent A3I-42 (peak GMT: 10,766). Titers for these groups 00 -q declined somewhat following the fifth and sixth doses. For C, 10 the remaining five immunogens, peak titers were reached IND following the fifth or the sixth dose and these were of much Slower magnitude than those of the four highest titer groups: A01-5 conjugate (peak GMT: 2,356), pBx6 (peak GMT: 1,986), A013-28 conjugate (peak GMT: 1,183), A033-42 conjugate (peak GMT: 658), A325-35 (peak GMT: 125). Antibody titers were also measured against the homologous peptides using the same ELISA sandwich format for a subset of the immunogens, those groups immunized with Al1-5, A013-28, A025-35, Af33-42 or rodent A4l-42. These titers were about the same as those measured against A61-42 except for the rodent A61-42 immunogen in which case antibody titers against the homologous immunogen were about two-fold higher. The magnitude of the AN1792-specific antibody titer of individual animals or the mean values of treatment groups did not correlate with efficacy measured as the reduction of A,3 in the cortex.

4. Lymphoproliferative Responses AO-dependent lymphoproliferation was measured using spleen cells harvested approximately one week following the final, sixth, immunization. Freshly harvested cells, 10 5 per well, were cultured for 5 days in the presence of A41-40 at a concentration of 5 AM for stimulation. Cells from a subset of seven of the ten groups were also cultured in the presence of the reverse peptide, A40-1. As a positive control, additional cells were cultured with the T cell mitogen, PHA, and, as a negative control, cells were cultured without added peptide.

SLymphocytes from a majority of the animals proliferated in response to PHA. There were no significant responses to the A/40-1 reverse peptide. Cells from animals immunized with the larger aggregated A0 peptides, AN1792, rodent A31-42 and AN1528 proliferated robustly when stimulated with A31-40 with the highest cpm in the recipients of AN1792. One animal in each of the groups immunized with A,1-12 conjugate, Af13-28 Sconjugate and A/25-35 proliferated in response to A01-40. The 00 C remaining groups receiving A31-5 conjugate, A33-42 conjugate pBx6 or PBS had no animals with an A-stimulated response.

These results are summarized in Table 5 below.

Table Immunogen Conjugate AO Amino Acids Responders A431-5 yes 5-mer 0/7 A31-12 yes 12-mer 1/8 A13-28 yes 16-mer 1/9 A025-35 11-mer 1/9 A333-42 yes 10-mer 0/10 A1-40 40-mer 5/8 A31-42 42-mer 9/9 r A,81-42 42-mer 8/8 pBx6 0/8 PBS 0-mer 0/8 These results show that AN1792 and AN1528 stimulate strong T cell responses, most likely of the CD4' phenotype. The absence of an A-specific T cell response in animals immunized with A$1-5 is not surprising since peptide epitopes recognized by CD4 T cells are usually about 15 amino acids in length, although shorter peptides can sometimes function with less efficiency. Thus the majority of helper T cell epitopes for the four conjugate peptides are likely to reside in the IgG conjugate partner, not in the A43 region. This hypothesis is supported by the very low incidence of proliferative responses for animals in each of these treatment groups. Since the A431- 5 conjugate was effective at significantly reducing the level 0 of AO in the brain, in the apparent absence of A-specific T cells, the key effector immune response induced by immunization with this peptide appears to be antibody.

Lack of T-cell and low antibody response from fusion peptide pBx6, encompassing APP amino acids 592-695 including all of the A0 residues may be due to the poor immunogenicity of this particular preparation. The poor immunogenicity of the A325- 00 C< 35 aggregate is likely due to the peptide being too small to C- be likely to contain a good T cell epitope to help the 10 induction of an antibody response. If this peptide were Sconjugated to a carrier protein, it would probably be more immunogenic.

V. Preparation of Polyclonal Antibodies for Passive Protection 20 non-transgenic mice are immunized with A43 or other immunogen, optionally plus adjuvant, and are euthanized at months. Blood is collected from immunized mice. Optionally, IgG is separated from other blood components. Antibody specific for the immunogen may be partially purified by affinity chromatography. An average of about 0.5-1 mg of immunogen-specific antibody is obtained per mouse, giving a total of 5-10 mg.

VI. Passive Immunization with Antibodies to A6 Groups of 7-9 month old PDAPP mice each are injected with 0.5 mg in PBS of polyclonal anti-A43 or specific anti-Ap monoclonals as shown below. All antibody preparations are purified to have low endotoxin levels. Monoclonals can be prepared against a fragment by injecting the fragment or longer form of AO into a mouse, preparing hybridomas and screening the hybridomas for an antibody that specifically binds to a desired fragment of A3 without binding to other nonoverlapping fragments of A3.

Table 6 Antibody Epitope 2H3 Af3 1-12 10D5 Af3 1-12 266 A$ 13-28 21F12 AO 33-42 Mouse polyclonal Anti-Aggregated A342 anti-human A/42 Mice are injected ip as needed over a 4 month period to maintain a circulating antibody concentration measured by ELISA titer of greater than 1/1000 defined by ELISA to A042 or other immunogen. Titers are monitored as above and mice are euthanized at the end of 4 months of injections.

Histochemistry, A0 levels and toxicology are performed post mortem. Ten mice are used per group.

VII. Comparison of Different Adiuvants This examples compares CFA, alum, an oil-in water emulsion and MPL for capacity to stimulate an immune response.

A. Materials and Methods 1. Study Desicn One hundred female Hartley strain six-week old guinea pigs, obtained from Elm Hill, were sorted into ten groups to be immunized with AN1792 or a palmitoylated derivative thereof combined with various adjuvants. Seven groups received injections of AN1792 (33yg unless otherwise specified) combined with a) PBS, b) Freund's adjuvant, c) MPL, d) squalene, e) MPL/squalene f) low dose alum, or g) high dose alum (300,ig AN1792). Two groups received injections of a palmitoylated derivative of AN1792 (33 pg) combined with a) PBS or b) squalene. A final, tenth group received PBS alone without antigen or additional adjuvant. For the group receiving Freund's adjuvant, the first dose was emulsified with CFA and the remaining four doses with IFA. Antigen was administered at a dose of 33 jg for all groups except the high dose alum group, which received 300 Ag of AN1792. Injections were administered intraperitoneally for CFA/IFA and intramuscularly in the hind limb quadriceps alternately on the right and left side for all other groups. The first three doses were given on a biweekly schedule followed by two doses at a monthly interval). Blood was drawn six to seven days following each immunization, starting after the second dose, for measurement of antibody titers.

2. Prenaration of Immunoqens Two mg A042 (California Peptide, Lot ME0339) was added to 0.9 ml of deionized water and the mixture was vortexed to generate a relatively uniform suspension. A 100 Al aliquot of PBS (IX PBS, 0.15 M NaCI, 0.01 M sodium phosphate, pH was added. The suspension was vortexed again and incubated overnight at 37 0 C for use the next day. Unused A,1-42 was stored with desiccant as a lyophilized powder at -20 0

C.

0 A palmitoylated derivative of AN1792 was prepared by coupling palmitic anhydride, dissolved in dimethyl formamide, to the amino terminal residue of AN1792 prior to removal of the nascent peptide from the resin by treatment with hydrofluoric acid.

To prepare vaccine doses with Complete Freund's adjuvant (CFA) (group 33 pg of AN1792 in 200 il PBS was emulsified C' 1:1 (vol:vol) with CFA in a final volume of 400 pl for the first immunization. For subsequent immunizations, the antigen

C

u 10 was similarly emulsified with Incomplete Freund's adjuvant 0 D(IFA).

To prepare vaccine doses with MPL for groups 5 and 8, lyophilized powder (Ribi ImmunoChem Research, Inc., Hamilton, MT) was added to 0.2% aqueous triethylamine to a final concentration of 1 mg/ml and vortexed. The mixture was heated to 65 to 70 0 C for 30 sec to create a slightly opaque uniform suspension of micelles. The solution was freshly prepared for each set of injections. For each injection in group 5, 33 jg of AN1792 in 16.5 Al PBS, 50 ig of MPL (50 jl) and 162 il of PBS were mixed in a borosilicate tube immediately before use.

To prepare vaccine doses with the low oil-in-water emulsion, AN1792 in PBS was added to 5% squalene, 0.5% Tween 0.5% Span 85 in PBS to reach a final single dose concentration of 33 pg AN1792 in 250 pl (group The mixture was emulsified by passing through a two-chambered hand-held device 15 to 20 times until the emulsion droplets appeared to be about equal in diameter to a 1.0 Am diameter standard latex bead when viewed under a microscope. The resulting suspension was opalescent, milky white. The emulsions were freshly prepared for each series of injections. For group 8, MPL in 0.2% triethylamine was added at a concentration of 50 jg per dose to the squalene and detergent mixture for emulsification as noted above. For the palmitoyl derivative (group 33 jg per dose of palmitoyl-NH-A1-42 was added to squalene and vortexed. Tween 80 and Span 85 were then added with vortexing. This mixture was added to PBS to reach final concentrations of 5% squalene, 0.5% Tween 80, 0.5% Span 85 and the mixture was emulsified as noted above.

To prepare vaccine doses with alum (groups 9 and AN1792 in PBS was added to Alhydrogel (aluminum hydroxide gel, Accurate, Westbury, NY) to reach concentrations of 33 Ag (low C dose, group 9) or 300 Ag (high dose, group 10) AN1792 per 5 mg 00 of alum in a final dose volume of 250 Al. The suspension was Sgently mixed for 4 hr at RT.

ND

3. Measurement of Antibody Titers Guinea pigs were bled six to seven days following immunization starting after the second immunization for a total of four bleeds. Antibody titers against A342 were measured by ELISA as described in General Materials and Methods.

4. Tissue Preoaration After about 14 weeks, all guinea pigs were administered

CO

2 Cerebrospinal fluid was collected and the brains were removed and three brain regions (hippocampus, cortex and cerebellum) were dissected and used to measure the concentration of total A protein using ELISA.

B. Results 1. Antibody Responses There was a wide range in the potency of the various adjuvants when measured as the antibody response to AN1792 following immunization. As shown in Fig. 14, when AN1792 was C administered in PBS, no antibody was detected following two or 00 three immunizations and negligible responses were detected following the fourth and fifth doses with geometric mean OD titers (GMTs) of only about 45. The o/w emulsion induced modest titers following the third dose (GMT 255) that were maintained following the fourth dose (GMT 301) and fell with the final dose (GMT 54). There was a clear antigen dose response for AN1792 bound to alum with 300 pg being more immunogenic at all time points than 33 pg. At the peak of the antibody response, following the fourth immunization, the difference between the two doses was 43% with GMTs of about 1940 (33 pg) and 3400 (300 Ag). The antibody response to 33 pg AN1792 plus MPL was very similar to that generated with almost a ten-fold higher dose of antigen (300 pg) bound to alum. The addition of MPL to an o/w emulsion decreased the potency of the vaccine relative to that with MPL as the sole adjuvant by as much as 75%. A palmitoylated derivative of AN1792 was completely non-immunogenic when administered in PBS and gave modest titers when presented in an o/w emulsion with GMTs of 340 and 105 for the third and fourth bleeds. The highest antibody titers were generated with Freund's adjuvant with a peak GMT of about 87,000, a value almost greater than the GMTs of the next two most potent vaccines, MPL and high dose AN1792/alum.

The most promising adjuvants identified in this study are MPL and alum. Of these two, MPL appears preferable because a lower antigen dose was required to generate the same antibody response as obtained with alum. The response can be increased by increasing the dose of antigen and /or adjuvant and by optimizing the immunization schedule. The o/w emulsion 0 was a very weak adjuvant for AN1792 and adding an o/w emulsion c-i to MPL adjuvant diminished the intrinsic adjuvant activity of MPL alone.

2. A Levels In The Brain 00 Ci 5 At about 14 weeks the guinea pigs were deeply -q anesthetized, the cerebrospinal fluid (CSF) was drawn and

C

u brains were excised from animals in a subset of the groups, Sthose immunized with Freund's adjuvant (group MPL (group alum with a high dose, 300 jg, of AN1792 (group 10) and the PBS immunized control group (group To measure the level of AO peptide, one hemisphere was dissected and homogenates of the hippocampal, cortical, and cerebellar regions were prepared in 5 M guanidine. These were diluted and quantitated by comparison to a series of dilutions of A43 standard protein of known concentrations in an ELISA format.

The levels of A0 protein in the hippocampus, the cortex and the cerebellum were very similar for all four groups despite the wide range of antibody responses to A0 elicited by these vaccines. Mean A3 levels of about 25 ng/g tissue were measured in the hippocampus, 21 ng/g in the cortex, and 12 ng/g in the cerebellum. Thus, the presence of a high circulating antibody titer to Af for almost three months in some of these animals did not alter the total A levels in their brains. The levels of AO in the CSF were also quite similar between the groups. The lack of large effect of AN1792 immunization on endogenous A3 indicates that the immune response is focused on pathological formations of A43.

VIII. Immune Response to Different Adjuvants in Mice Six-week old female Swiss Webster mice were used for this study with 10-13 animals per group. Immunizations were given 64 on days 0, 14, 28, 60, 90 and 20 administered subcutaneously Cl in a dose volume of 200 pl. PBS was used as the buffer for all formulations. Animals were bleed seven days following each immunization starting after the second dose for analysis 0 5 of antibody titers by ELISA. The treatment regime of each group is summarized in Table 7.

00 Table 7 Experimental Design of Betabloc Study 010 Group N a Adjuvant bDose Antigen Dose N1923 1 10 MPL 25 tig AN1792 33 3 10 MPL 50 jig AN1792 33 3 10 MPL 15 jig AN1792 33 4 13 MPL 15 jig AN1792 330 6 13 MPL 50 jig AN1528 33 7 10 PBS AN1792 33 8 10 PBS none 9 10 Squalene 5% AN1792 33 emulsified 10 Squalene 5% AN1792 33 admixed________ 1 1 10 Alum 2 mg AN1792 33 12 13 MPL Alum 50 tig/2 mg AN1792 33 13 10 QS21 5 jig AN1792 33 14 10 QS21 10 jig AN1792 33 10 QS21 25 jig AN1792 33 16 13 QS21 25 jig AN1792 150 17 13 QS21 25 jig AN1528 33 18 13 QS21 MPL 25 jig/5O tig AN1792 33 19 13 QS21 Alum 25 lig/2 mg AN1792 33 Footnotes: a Number of mice in each group at the initiation of the experiment.

The adjuvants are noted. The buffer for all these formulations was PBS. For group 8, there was no adjuvant and no antigen.

The ELISA titers of antibodies against Afl42 in each group are shown in Table 8 below.

Table 8.

a' 5 00 .0 CN .0 Geometric Mean Antibody Titers Week of Bleed Treatment Group 2.9 5.0 8.7 12.9 16.7 1 248 1797 2577 6180 4177 2 598 3114 3984 5287 6878 3 1372 5000 7159 12333 12781 4 1278 20791 14368 20097 25631 5 3288 26242 13229 9315 23742 6 61 2536 2301 1442 4504 7 37 395 484 972 2149 8 25 25 25 25 9 25 183 744 952 1823 10 25 89 311 513 817 11 29 708 2618 2165 3666 12 198 1458 1079 612 797 13 38 433 566 1080 626 14 104 541 3247 1609 838 212 2630 2472 1224 1496 16 183 2616 6680 2085 1631 17 28 201 375 222 1540 18 31699 15544 23095 6412 9059 19 63 243 554 299 441 The table shows that the highest titers were obtained for groups 4, 5 and 18, in which the adjuvants were 125 ug MPL, 50 jg MPL and QS21 plus MPL.

IX. Therapeutic Efficacy of Different Adjuvants A therapeutic efficacy study was conducted in PDAPP transgenic mice with a set of adjuvants suitable for use in humans to determine their ability to potentiate immune responses to A, and to induce the immune-mediated clearance of amyloid deposits in the brain.

One hundred eighty male and female, 7.5- to 8.5-month old OC heterozygous PDAPP transgenic mice were obtained from Charles River Laboratories. The mice were sorted into nine groups containing 15 to 23 animals per group to be immunized with O 5 AN1792 or AN1528 combined with various adjuvants. Animals were distributed to match the gender, age, and parentage of the animals within the groups as closely as possible. The adjuvants included alum, MPL, and QS21, each combined with 00 C< both antigens, and Freund's adjuvant (FA) combined with only S 10 AN1792. An additional group was immunized with AN1792 ND formulated in PBS buffer plus the preservative thimerosal Swithout adjuvant. A ninth group was immunized with PBS alone as a negative control.

Preparation of aggregated A0 peptides: human A31-40 (AN1528; California Peptides Inc., Napa, CA; Lot ME0541) and human A01-42 (AN1792; California Peptides Inc., Lot ME0439) peptides were freshly solubilized for the preparation of each set of injections from lyophilized powders that had been stored desiccated at -20 0 C. For this purpose, two mg of peptide were added to 0.9 ml of deionized water and the mixture was vortexed to generate a relatively uniform solution or suspension. AN1528 was soluble at this step, in contrast to AN1792. A 100 Al aliquot of 10X PBS (IX PBS: 0.15 M NaCI, 0.01 M sodium phosphate, pH 7.5) was then added at which point AN1528 began to precipitate. The suspensions were vortexed again and incubated overnight at 37 0 C for use the next day.

To prepare vaccine doses with alum (Groups 1 and A3 peptide in PBS was added to Alhydrogel (two percent aqueous aluminum hydroxide gel, Sargeant, Inc., Clifton, NJ) to reach concentrations of 100 Mg A, peptide per 1 mg of alum. 10X PBS was added to a final dose volume of 200 Al in IX PBS. The suspension was then gently mixed for approximately 4 hr at RT prior to injection.

To prepare vaccine doses for with MPL (Groups 2 and 6), lyophilized powder (Ribi ImmunoChem Research, Inc., Hamilton, 0 MT; Lot 67039-E0896B) was added to 0.2% aqueous triethylamine c- to a final concentration of 1 mg/ml and vortexed. The mixture was heated to 65 to 700°C for 30 sec to create a slightly opaque uniform suspension of micelles. The solution was stored at 4°C. For each set of injections, 100 gg of peptide per dose in 50 pl PBS, 50 ig of MPL per dose (50 il) and 100 gl of PBS per dose were mixed in a borosilicate tube immediately before use.

00 c- To prepare vaccine doses with QS21 (Groups 3 and 7), lyophilized powder (Aquila, Framingham, MA; Lot A7018R) was Sadded to PBS, pH 6.6-6.7 to a final concentration of 1 mg/ml and vortexed. The solution was stored at -20°C. For each set of injections, 100 pg of peptide per dose in 50 pl PBS, 25 Ig of QS21 per dose in 25 pl PBS and 125 Al of PBS per dose were mixed in a borosilicate tube immediately before use.

To prepare vaccine doses with Freund's Adjuvant (Group 4), 100 Mg of AN1792 in 200 Al PBS was emulsified 1:1 (vol:vol) with Complete Freund's Adjuvant (CFA) in a final volume of 400 Al for the first immunization. For subsequent immunizations, the antigen was similarly emulsified with Incomplete Freund's Adjuvant (IFA). For the vaccines containing the adjuvants alum, MPL or QS21, 100 Ag per dose of AN1792 or AN1528 was combined with alum (1 mg per dose) or MPL (50 Mg per dose) or QS21 (25 Mg per dose) in a final volume of 200 Al PBS and delivered by subcutaneous inoculation on the back between the shoulder blades. For the group receiving FA, 100 Mg of AN1792 was emulsified 1:1 (vol:vol) with Complete Freund's adjuvant (CFA) in a final volume of 400 Ml and delivered intraperitoneally for the first immunization, followed by a boost of the same amount of immunogen in Incomplete Freund's adjuvant (IFA) for the subsequent five doses. For the group receiving AN1792 without adjuvant, 10 Mg AN1792 was combined with 5 Mg thimerosal in a final volume of 50 Ml PBS and delivered subcutaneously. The ninth, control group received only 200 il PBS delivered subcutaneously. Immunizations were given on a biweekly schedule for the first three doses, then on a monthly schedule thereafter on days 0, 16, 28, 56, 85 and c-i 112. Animals were bled six to seven days following each immunization starting after the second dose for the _n measurement of antibody titers. Animals were euthanized approximately one week after the final dose. Outcomes were measured by ELISA assay of A0 and APP levels in brain and by immunohistochemical evaluation of the presence of amyloid plaques in brain sections. In addition, Afl-specific antibody 00 c-i titers, and Af3-dependent proliferative and cytokine responses were determined.

Table 9 shows that the highest antibody titers to A,61-42 were elicited with FA and AN1792, titers which peaked following the fourth immunization (peak GMT: 75,386) and then declined by 59% after the final, sixth immunization. The peak mean titer elicited by MPL with AN1792 was 62k lower than that generated with FA (peak GMT: 28,867) and was also reached early in the immunization scheme, after 3 doses, followed by a decline to 28% of the peak value after the sixth immunization.

The peak mean titer generated with QS21 combined with AN1792 (GMT: 1,511) was about 5-fold lower than obtained with MPL.

In addition, the kinetics of the response were slower, since an additional immunization was required to reach the peak response. Titers generated by alum-bound AN1792 were marginally greater than those obtained with QS21 and the response kinetics were more rapid. For AN1792 delivered in PB3S with thimerosal the frequency and size of titers were barely greater than that for PBS alone. The peak titers generated with MPL and AN1528 (peak GMT 3099) were about 9f old lower than those with AN1792. Alum-bound AN1528 was very poorly immunogenic with low titers generated in only some of the animals. No antibody responses were observed in the control animals immunized with PBS alone.

Table 9 Geometric Mean Antibody Titers' Week of Bleed Treatment 3. 5.0 9. 13. 17.0 Alum/ 102 1,081 2,366 1,083 572 AN1792 (12/2 (17/20) (21/21) (19/21) (18/21) MPL/ 6241 28,867 1,1242 5,65 AN1792 (21/21) (21/21) (21/21) (20/20) (20/20) QS21I 30 227 327 1,511 1,188 AN 1792 (1/20) (10/19) (10/19) (17/18) (14/18) CFA/ 007 61,27 7386 4162 M3 AN1792 (15/15) (15/15) (15/15) (15/15) (15/15) Alum/ 25 33 39 37 31 AN1528 (0/21) (1/21) (3/20) (1/20) (2/20) MPL/ 1W4 1,65T3T 1,156 AN1528 (15/21) (20/21) (21/21) (20/20) (20/20) QS21I 29 221 51 826 2,994 AN1528 (1/22) (13/22) (4/22) (20/22) (21/22) PBS plus 25 3~ 33 39 _T 47 Thimerosal (0/16) (2/16) (4/16) (3/16) (4/16) PBS 25 25 25 25 (0/16) (0/15) (0/12) (0/16) Footnotes: Geometric mean antibody titers measured against AO 1-42 bNumber of responders per group The results of AN1792 or AN1592 treatment with various adjuvants, or thimerosal on cortical amyloid burden in 12month old mice determined by ELISA are shown in Fig. 15. In PES control PDAPP mice, the median level of total A,6 in the cortex at 12 months was 1,817 ng/g. Notably reduced levels of c-i A3 were observed in mice treated with AN1792 plus CFA/IFA, AN1792 plus alum, AN1792 plus MPL and QS21 plus AN1792. The reduction reached statistical significance (p<0.05) only for AN1792 plus CFA/IFA. However, as shown in Examples I and III, the effects of immunization in reducing A,8 levels become substantially greater in 15 month and 18 month old mice.

Thus, it is expected that at least the AN1792 plus alum, 00 CIq AN1792 plus MPL and AN1792 plus QS21 compositions will achieve -1 0 statistical significance in treatment of older mice. By Icontrast, the AN1792 plus the preservative thimerosal showed a median level of A43 about the same as that in the PBS treated c-i mice. Similar results were obtained when cortical levels of A042 were compared. The median level of A342 in PBS controls was 1624 ng/g. Notably reduced median levels of 403, 1149, 620 and 714 were observed in the mice treated with AN1792 plus CFA/IFA, AN1792 plus alum, AN1792 plus MPL and AN1792 plus QS21 respectively, with the reduction achieving statistical significance (p=0.05) for the AN1792 CFA/IFA treatment group.

The median level in the AN1792 thimerosal treated mice was 1619 ng/g A042.

X. Toxicity Analysis Tissues were collected for histopathologic examination at the termination of studies described in Examples 2, 3 and 7.

In addition, hematology and clinical chemistry were performed on terminal blood samples from Examples 3 and 7. Most of the major organs were evaluated, including brain, pulmonary, lymphoid, gastrointestinal, liver, kidney, adrenal and gonads.

Although sporadic lesions were observed in the study animals, there were no obvious differences, either in tissues affected or lesion severity, between AN1792 treated and untreated animals. There were no unique histopathological lesions noted in AN-1782-immunized animals compared to PBS-treated or untreated animals. There were also no differences in the clinical chemistry profile between adjuvant groups and the PBS treated animals in Example 7. Although there were significant increases in several of the hematology parameters between animals treated with AN1792 and Freund's adjuvant in Example 7 C 5 relative to PBS treated animals, these type of effects are expected from Freund's adjuvant treatment and the accompanying peritonitis and do not indicate any adverse effects from C AN1792 treatment. Although not part of the toxicological 00 00 evaluation, PDAPP mouse brain pathology was extensively examined as part of the efficacy endpoints. No sign of ND treatment related adverse effect on brain morphology was noted Sin any of the studies. These results indicate that AN1792 treatment is well tolerated and at least substantially free of side effects.

XI. Prevention and Treatment of Subjects A single-dose phase I trial is performed to determine safety. A therapeutic agent is administered in increasing dosages to different patients starting from about 0.01 the level of presumed efficacy, and increasing by a factor of three until a level of about 10 times the effective mouse dosage is reached.

A phase II trial is performed to determine therapeutic efficacy. Patients with early to mid Alzheimer's Disease defined using Alzheimer's disease and Related Disorders Association (ADRDA) criteria for probable AD are selected.

Suitable patients score in the 12-26 range on the Mini-Mental State Exam (MMSE). Other selection criteria are that patients are likely to survive the duration of the study and lack complicating issues such as use of concomitant medications that may interfere. Baseline evaluations of patient function are made using classic psychometric measures, such as the MMSE, and the ADAS, which is a comprehensive scale for evaluating patients with Alzheimer's Disease status and function. These psychometric scales provide a measure of progression of the Alzheimer's condition. Suitable qualitative life scales can also be used to monitor treatment.

Disease progression can also be monitored by MRI. Blood profiles of patients can also be monitored including assays of immunogen-specific antibodies and T-cells responses.

C Following baseline measures, patients begin receiving o00 c- treatment. They are randomized and treated with either Stherapeutic agent or placebo in a blinded fashion. Patients .O 10 are monitored at least every six months. Efficacy is Sdetermined by a significant reduction in progression of a treatment group relative to a placebo group.

A second phase II trial is performed to evaluate conversion of patients from non-Alzheimer's Disease early memory loss, sometimes referred to as age-associated memory impairment (AAMI), to probable Alzheimer's disease as defined as by ADRDA criteria. Patients with high risk for conversion to Alzheimer's Disease are selected from a non-clinical population by screening reference populations for early signs of memory loss or other difficulties associated with pre- Alzheimer's symptomatology, a family history of Alzheimer's Disease, genetic risk factors, age, sex, and other features found to predict high-risk for Alzheimer's Disease. Baseline scores on suitable metrics including the MMSE and the ADAS together with other metrics designed to evaluate a more normal population are collected. These patient populations are divided into suitable groups with placebo comparison against dosing alternatives with the agent. These patient populations are followed at intervals of about six months, and the endpoint for each patient is whether or not he or she converts to probable Alzheimer's Disease as defined by ADRDA criteria at the end of the observation.

0 XII. General Materials and Methods 1. Measurement of Antibody Titers Mice were bled by making a small nick in the tail vein and collecting about 200 pl of blood into a microfuge tube.

Guinea pigs were bled by first shaving the back hock area and 0C then using an 18 gauge needle to nick the metatarsal vein and 00 collecting the blood into microfuge tubes. Blood was allowed to clot for one hr at room temperature vortexed, then NO centrifuged at 14,000 x g for 10 min to separate the clot from 0 10 the serum. Serum was then transferred to a clean microfuge tube and stored at 40 C until titered.

Antibody titers were measured by ELISA. 96-well microtiter plates (Costar EIA plates) were coated with 100 Al of a solution containing either 10 Ag/ml either A4342 or SAPP or other antigens as noted in each of the individual reports in Well Coating Buffer (0.1 M sodium phosphate, pH 8.5, 0.1% sodium azide) and held overnight at RT. The wells were aspirated and sera were added to the wells starting at a 1/100 dilution in Specimen Diluent (0.014 M sodium phosphate, pH 7.4, 0.15 M NaCI, 0.6% bovine serum albumin, 0.05% thimerosal). Seven serial dilutions of the samples were made directly in the plates in three-fold steps to reach a final dilution of 1/218,700. The dilutions were incubated in the coated-plate wells for one hr at RT. The plates were then washed four times with PBS containing 0.05% Tween 20. The second antibody, a goat anti-mouse Ig conjugated to horseradish peroxidase (obtained from Boehringer Mannheim), was added to the wells as 100 Al of a 1/3000 dilution in Specimen Diluent and incubated for one hr at RT. Plates were again washed four times in PBS, Tween 20. To develop the chromogen, 100 Al of Slow TMB (3,3',5,5'-tetramethyl benzidine obtained from Pierce Chemicals) was added to each well and incubated for 15 min at RT. The reaction was stopped by the addition of 25 Al of 2 M H 2

SO

4 The color intensity was then read on a Molecular Devices Vmax at (450 nm 650 nm).

0 Titers were defined as the reciprocal of the dilution of serum giving one half the maximum OD. Maximal OD was generally taken from an initial 1/100 dilution, except in -i cases with very high titers, in which case a higher initial dilution was necessary to establish the maximal OD. If the point fell between two dilutions, a linear extrapolation was made to calculate the final titer. To calculate geometric Smean antibody titers, titers less than 100 were arbitrarily 00 assigned a titer value of 2. Lymphocyvte proliferation assay Mice were anesthetized with isoflurane. Spleens were removed and rinsed twice with 5 ml PBS containing 10% heatinactivated fetal bovine serum (PBS-FBS) and then homogenized in a 50 p Centricon unit (Dako A/S, Denmark) in 1.5 ml PBS-FBS for 10 sec at 100 rpm in a Medimachine (Dako) followed by filtration through a 100 A pore size nylon mesh. Splenocytes were washed once with 15 ml PBS-FBS, then pelleted by centrifugation at 200 x g for 5 min. Red blood cells were lysed by resuspending the pellet in 5 mL buffer containing 0.15 M NH 4 Cl, 1 M KHCO 3 0.1 M NaEDTA, pH 7.4 for five min at RT. Leukocytes were then washed as above. Freshly isolated spleen cells (105 cells per well) were cultured in triplicate sets in 96-well U-bottomed tissue culture-treated microtiter plates (Corning, Cambridge, MA) in RPMI 1640 medium (JRH Biosciences, Lenexa, KS) supplemented with 2.05 mM L glutamine, 1% Penicillin/Streptomycin, and 10% heatinactivated FBS, for 96 hr at 37 0 C. Various AO peptides, A431- 16, Af3l-40, A31-42 or A,340-1 reverse sequence protein were also added at doses ranging from 5 AM to 0.18 AM in four steps. Cells in control wells were cultured with Concanavalin A (Con A) (Sigma, cat. C-5275, at 1 Ag/ml) without added protein. Cells were pulsed for the final 24 hr with 3

H-

thymidine (1 ACi/well obtained from Amersham Corp., Arlington Heights IL). Cells were then harvested onto UniFilter plates and counted in a Top Count Microplate Scintillation Counter (Packard Instruments, Downers Grove, IL). Results are expressed as counts per minute (cpm) of radioactivity incorporated into insoluble macromolecules.

4. Brain Tissue Preparation 00 SAfter euthanasia, the brains were removed and one s0D hemisphere was prepared for immunohistochemical analysis, Swhile three brain regions (hippocampus, cortex and cerebellum) were dissected from the other hemisphere and used to measure the concentration of various A/3 proteins and APP forms using specific ELISAs (Johnson-Wood et al., supra).

Tissues destined for ELISAs were homogenized in 10 volumes of ice-cold guanidine buffer (5.0 M guanidine-HC1, 50 mM Tris- HC1, pH The homogenates were mixed by gentle agitation using an Adams Nutator (Fisher) for three to four hr at RT, then stored at -20°C prior to quantitation of AO and APP.

Previous experiments had shown that the analytes were stable under this storage condition, and that synthetic AO protein (Bachem) could be quantitatively recovered when spiked into homogenates of control brain tissue from mouse littermates (Johnson-Wood et al., supra).

Measurement of A8 Levels The brain homogenates were diluted 1:10 with ice cold Casein Diluent (0.25% casein, PBS, 0.05% sodium azide, Ag/ml aprotinin, 5 mM EDTA pH 8.0, 10 pg/ml leupeptin) and then centrifuged at 16,000 x g for 20 min at 40 C. The synthetic A$3 protein standards (1-42 amino acids) and the APP standards were prepared to include 0.5 M guanidine and 0.1% bovine serum albumin (BSA) in the final composition. The 0 "total" A3 sandwich ELISA utilizes monoclonal antibody (mA3) 266, specific for amino acids 13-28 of A3 (Seubert, et al.), as the capture antibody, and biotinylated mA3 3D6, specific for amino acids 1-5 of Af (Johnson-Wood, et al), as the reporter antibody. The 3D6 mA3 does not recognize secreted APP or full-length APP, but detects only A3 species with an amino-terminal aspartic acid. This assay has a lower limit of 0 sensitivity of ~50 pg/ml (11 pM) and shows no cross-reactivity 00 (1q to the endogenous murine AO protein at concentrations up to 1 C 10 ng/ml (Johnson-Wood et al., supra).

0 The A81-42 specific sandwich ELISA employs mA3 21F12, specific for amino acids 33-42 of AO (Johnson-Wood, et al.), as the capture antibody. Biotinylated mA3 3D6 is also the reporter antibody in this assay which has a lower limit of sensitivity of about 125 pg/ml (28 pM, Johnson-Wood et al.).

For the A,3 ELISAs, 100 p1 of either mA43 266 (at 10 pg/ml) or mA3 21F12 at (5 pg/ml) was coated into the wells of 96-well immunoassay plates (Costar) by overnight incubation at RT.

The solution was removed by aspiration and the wells were blocked by the addition of 200 p1 of 0.25% human serum albumin in PBS buffer for at least 1 hr at RT. Blocking solution was removed and the plates were stored desiccated at 4 0 °C until used. The plates were rehydrated with Wash Buffer [Trisbuffered saline (0.15 M NaCl, 0.01 M Tris-HCl, pH plus 0.05% Tween 201 prior to use. The samples and standards were added in triplicate aliquots of 100 pl per well and then incubated overnight at 40 C. The plates were washed at least three times with Wash Buffer between each step of the assay.

The biotinylated mA 3D6, diluted to 0.5 pg/ml in Casein Assay Buffer (0.25% casein, PBS, 0.05% Tween 20, pH was added and incubated in the wells for 1 hr at RT. An avidinhorseradish peroxidase conjugate, (Avidin-HRP obtained from Vector, Burlingame, CA), diluted 1:4000 in Casein Assay Buffer, was added to the wells for 1 hr at RT. The colorimetric substrate, Slow TMB-ELISA (Pierce), was added and allowed to react for 15 minutes at RT, after which the enzymatic reaction was stopped by the addition of 25 pl 2 N

SH

2

SO

4 The reaction product was quantified using a Molecular Devices Vmax measuring the difference in absorbance at 450 nm and 650 nm.

6. Measurement of APP Levels 00 q 5 Two different APP assays were utilized. The first, designated APP-a/FL, recognizes both APP-alpha and full- ND length (FL) forms of APP. The second assay is specific for SAPP-a. The APP-a/FL assay recognizes secreted APP including the first 12 amino acids of Aj3. Since the reporter antibody (2H3) is not specific to the a-clip-site, occurring between amino acids 612-613 of APP695 (Esch et al., Science 248, 1122- 1124 (1990)); this assay also recognizes full length APP (APP- FL). Preliminary experiments using immobilized APP antibodies to the cytoplasmic tail of APP-FL to deplete brain homogenates of APP-FL suggest that approximately 30-40% of the APP-a/FL APP is FL (data not shown). The capture antibody for both the APP-a/FL and APP-a assays is mA3 8E5, raised against amino acids 444 to 592 of the APP695 form (Games et al., supra).

The reporter mA$ for the APP-a/FL assay is mAO 2H3, specific for amino acids 597-608 of APP695 (Johnson-Wood et al., supra) and the reporter antibody for the APP-a assay is a bio.tinylated derivative of mA0 16H9, raised to amino acids 605 to 611 of APP. The lower limit of sensitivity of the APP-a/FL assay is about 11 ng/ml (150 pM) (Johnson-Wood et al.) and that of the APP-a specific assay is 22 ng/ml (0.3 nM). For both APP assays, mA3 8E5 was coated onto the wells of 96-well EIA plates as described above for mA 266. Purified, recombinant secreted APP-a was used as the reference standard for the APP-a assay and the APP-a/FL assay (Esch et al., supra). The brain homogenate samples in 5 M guanidine were diluted 1:10 in ELISA Specimen Diluent (0.014 M phosphate buffer, pH 7.4, 0.6% bovine serum albumin, 0.05% thimerosal, M NaCl, 0.1% NP40). They were then diluted 1:4 in Specimen Diluent containing 0.5 M guanidine. Diluted homogenates were then centrifuged at 16,000 x g for 15 seconds at RT. The APP standards and samples were added to the plate in duplicate aliquots and incubated for 1.5 hr at RT. The -n biotinylated reporter antibody 2H3 or 16H9 was incubated with 5 samples for 1 hr at RT. Streptavidin-alkaline phosphatase (Boehringer Mannheim), diluted 1:1000 in specimen diluent, was incubated in the wells for 1 hr at RT. The fluorescent

C

OC substrate 4-methyl-umbellipheryl-phosphate was added for a 00 min RT incubation and the plates were read on a Cytofluor tm 0 10 2350 fluorimeter (Millipore) at 365 nm excitation and 450 nm k0D emission.

7. Immunohistochemistry Brains were fixed for three days at 4 0 C in 4% paraformaldehyde in PBS and then stored from one to seven days at 4 0 C in 1% paraformaldehyde, PBS until sectioned. Fortymicron-thick coronal sections were cut on a vibratome at RT and stored in cryoprotectant (30% glycerol, 30% ethylene glycol in phosphate buffer) at -20 0 °C prior to immunohistochemical processing. For each brain, six sections at the level of the dorsal hippocampus, each separated by consecutive 240 km intervals, were incubated overnight with one. of the following antibodies: a biotinylated anti-A3 (mA, 3D6, specific for human Af3) diluted to a concentration of 2 Ag/ml in PBS and 1% horse serum; or a biotinylated mAj3 specific for human APP, 8E5, diluted to a concentration of 3 Ag/ml in PBS and 1.0% horse serum; or a mA specific for glial fibrillary acidic protein (GFAP; Sigma Chemical Co.) diluted 1:500 with 0.25% Triton X-100 and 1% horse serum, in Tris-buffered saline, pH 7.4 (TBS); or a mA specific for CD11b, MAC-1 antigen, (Chemicon International) diluted 1:100 with 0.25% Triton X-100 and 1% rabbit serum in TBS; or a mA3 specific for MHC II antigen, (Pharmingen) diluted 1:100 with 0.25% Triton X-100 and 1% rabbit serum in TBS; or a rat mAO specific for CD 43 (Pharmingen) diluted 1:100 with 1% rabbit serum in PBS or a rat mA3 specific for CD 0 (Pharmingen) diluted 1:100 with 1% rabbit serum in PBS; or (8) a rat monoclonal AO specific for CD 45RB (Pharmingen) diluted 1:100 with 1% rabbit serum in PBS; or a rat monoclonal AR 5 specific for CD 45 (Pharmingen) diluted 1:100 with 1% rabbit serum in PBS; or (10) a biotinylated polyclonal hamster A3 specific for CD3e (Pharmingen) diluted 1:100 with 1% rabbit serum in PBS or (11) a rat mA3 specific for.CD3 (Serotec) 0 0 diluted 1:200 with 1% rabbit serum in PBS; or with (12) a 0 10 solution of PBS lacking a primary antibody containing 1% y0 normal horse serum.

CA Sections reacted with antibody solutions listed in 1,2 and 6-12 above were pretreated with 1.0% Triton X-100, 0.4% hydrogen peroxide in PBS for 20 min at RT to block endogenous peroxidase. They were next incubated overnight at 4°C with primary antibody. Sections reacted with 3D6 or 8E5 or CD3e mA3s were then reacted for one hr at RT with a horseradish peroxidase-avidin-biotin-complex with kit components and diluted 1:75 in PBS (Vector Elite Standard Kit, Vector Labs, Burlingame, Sections reacted with antibodies specific for CD 45RA, CD 45RB, CD 45, CD3 and the PBS solution devoid of primary antibody were incubated for 1 hour at RT with biotinylated anti-rat IgG (Vector) diluted 1:75 in PBS or biotinylated anti-mouse IgG (Vector) diluted 1:75 in PBS, respectively. Sections were then reacted for one hr at RT with a horseradish peroxidase-avidin-biotin-complex with kit components and diluted 1:75 in PBS (Vector Elite Standard Kit, Vector Labs, Burlingame, CA.).

Sections were developed in 0.01% hydrogen peroxide, 0.05% 3,3'-diaminobenzidine (DAB) at RT. Sections destined for incubation with the GFAP-, MAC-1- AND MHC II-specific antibodies were pretreated with 0.6% hydrogen peroxide at RT to block endogenous peroxidase then incubated overnight with the primary antibody at 4 0 C. Sections reacted with the GFAP antibody were incubated for 1 hr at RT with biotinylated antimouse IgG made in horse (Vector Laboratories; Vectastain Elite Nu ABC Kit) diluted 1:200 with TBS. The sections were next 0 reacted for one hr with an avidin-biotin-peroxidase complex (Vector Laboratories; Vectastain Elite ABC Kit) diluted 1:1000 with TBS. Sections incubated with the MAC-1-or MHC II- .D 5 specific mA,3 as the primary antibody were subsequently reacted for 1 hr at RT with biotinylated anti-rat IgG made in rabbit diluted 1:200 with TBS, followed by incubation for one hr with C avidin-biotin-peroxidase complex diluted 1:1000 with TBS.

00 Sections incubated with GFAP-, MAC-1- and MHC II-specific antibodies were then visualized by treatment at RT with 0.05% 0D DAB, 0.01% hydrogen peroxide, 0.04% nickel chloride, TBS for 4 and 11 min, respectively.

Immunolabeled sections were mounted on glass slides (VWR, Superfrost slides), air dried overnight, dipped in Propar (Anatech) and overlaid with coverslips using Permount (Fisher) as the mounting medium.

To counterstain A0 plaques, a subset of the GFAP-positive sections were mounted on Superfrost slides and incubated in aqueous 1% Thioflavin S (Sigma) for 7 min following immunohistochemical processing. Sections were then dehydrated and cleared in Propar, then overlaid with coverslips mounted with Permount.

8. Image Analysis A Videometric 150 Image Analysis System (Oncor, Inc., Gaithersburg, MD) linked to a Nikon Microphot-FX microscope through a CCD video camera and a Sony Trinitron monitor was used for quantification of the immunoreactive slides. The image of the section was stored in a video buffer and a colorand saturation-based threshold was determined to select and calculate the total pixel area occupied by the immunolabeled structures. For each section, the hippocampus was manually outlined and the total pixel area occupied by the hippocampus was calculated. The percent amyloid burden was measured as: 0 (the fraction of the hippocampal area containing A,6 deposits immunoreactive with mA3 3D6) x 100. Similarly, the percent -n neuritic burden was measured as: (the fraction of the k0 5 hippocampal area containing dystrophic neurites reactive with mA3 8E5) x100. The C-Imaging System (Compix, Inc., Cranberry Township, PA) operating the Simple 32 Software Application 0\ program was linked to a Nikon Microphot-FX microscope through 0 0 an Optronics camera and used to quantitate the percentage of the retrospenial cortex occupied by GFAP-positive astrocytes and MAC-1-and MHC II-positive microglia. The image of the immunoreacted section was stored in a video buffer and a monochrome-based threshold was determined to select and calculate the total pixel area occupied by immunolabeled cells. For each section, the retrosplenial cortex (RSC) was manually outlined and the total pixel area occupied by the RSC was calculated. The percent astrocytosis was defined as: (the fraction of RSC occupied by GFAP-reactive astrocytes) X 100.

Similarly, percent microgliosis was defined as: (the fraction of the RSC occupied by MAC-1- or MHC II-reactive microglia) X 100. For all image analyses, six sections at the level of the dorsal hippocampus, each separated by consecutive 240 Am intervals, were quantitated for each animal. In all cases, the treatment status of the animals was unknown to the observer.

Although the foregoing invention has been described in detail for purposes of clarity of understanding, it will be obvious that certain modifications may be practiced within the scope of the appended claims. All publications and patent documents cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each were so individually denoted.

2006202899 06 Jul 2006 TABLE 1 TITER AT 50% MAXIMAL _________Aggroated AR Injected mIce Age of PDAPP mouse 100 mouse 101 mouse 102 mouse 103 mouse 104 mouse 105 mouse 106 mouse 107 mouse 108 4 70000 150000 15000 120000 1000 15000 50000 80000 100000 6 15000 65000 30000 55000 300 15000 15000 50000 60000 8 20000 55000 50000 50000 400 15000 18000 50000 60000 40000 20000 60000 50000 900 15000 50000 20000 40000 12 25000 30000 60000 40000 2700 20000 70000 25000 20000 PBS Injected mice on both Immunogen at 1,100 AgofPDAPP mouse 113 mouse 114 mousellS mousell6 -mousell7 i4xibkg 4x bkg <4bg 4x bkg :S 'l xb 4x bkg 4x bkg 4x bkg 4x bkg <4x bkQA <4xbkg" 4x bkq <4x bkq <4x bkq

Claims (45)

1. A pharmaceutical composition comprising an agent effective to induce an immunogenic response against AO in a patient, and a pharmaceutically acceptable adjuvant. S 2. The pharmaceutical composition of claim 1, wherein the agent is AO or an active fragment thereof.

3. The pharmaceutical composition of claim 1 or 2, wherein the adjuvant comprises alum.

4. The pharmaceutical composition of claim 1 or 2, wherein 1i the adjuvant comprises monophosphoryl lipid (MPL). The pharmaceutical composition of claim 1 or 2, wherein the adjuvant comprises QS21.

6. The pharmaceutical composition of any of the preceding claims, wherein the A43 or fragment is a component of a particle.

7. The pharmaceutical composition of claim 6, wherein the particle is a polylactide polyglycolide copolymer (PLPG) particle.

8. A method of preventing or treating a disease characterized by amyloid deposit in a patient, comprising: administering an agent effective to induce an immune response against a peptide component of an amyloid deposit in the patient.

9. The method of claim 8, wherein the amyloid deposit comprises aggregated A3 peptide. The method of claim 8 or 9,.wherein the patient is a human.

11. The method of any of the preceding claims, wherein the disease is Alzheimer's disease.

12. The method of any of the preceding claims, wherein the patient is asymptomatic.

13. The method of any of the preceding claims, wherein .S the patient is under

14. The method of any of the preceding claims, wherein the patient has inherited risk factors indicating susceptibility to Alzheimer's disease. The method of any of claims 8-13, wherein the patient has no known risk factors for Alzheimer's disease.

16. The method of any of the preceding claims, wherein the agent comprises A/ peptide or an active fragment thereof. S 17. The method of any of the preceding claims, wherein the agent is A0 peptide or an active fragment thereof.

18. The method of claim 17, wherein the dose of A6 peptide administered to the patient at least 50 pg.

19. The method of claim 17, wherein the dose of A3 peptide administered to the patient is at least 100 pg. The method of any of the preceding claims, wherein the A3 peptide is A042.

21. The method of claim 20, wherein the AO peptide is administered in aggregated form. N 22. The method of claim any of the preceding claims, wherein the immune response comprises antibodies that bind to Cl the A,6 peptide.

23. The method of any of the preceding claims, wherein the 0C 5 immune response comprises T-cells that bind to the A0 peptide OO as a component of an MHC I or MHC II complex. ND

24. The method of any one of claims 8, or 10-15 wherein agent is an antibody to A0 which induces an immune response by binding to Aj in the patient.

25. The method of claims 8 or 10-15, wherein T-cells are removed from the patient, contacted with A,3 peptide under conditions in which the T-cells are primed, and the primed T- cells are administered to the patient.

26. The method of any of the preceding claims, wherein the agent is administered orally, subcutaneously, intramuscularly, topically or intravenously.

27. The method of any of the preceding claims, wherein the agent is administered intramuscularly or subcutaneously.

28. The method of any of the preceding claims, further comprising screening a library of compounds to identify a compound reactive with antibodies to AS, and administering the compound to the patient to induce the immune response.

29. The method of any one of claims 8, 10-15, 26 or 27, wherein the agent is an effective dose of a nucleic acid encoding A3 or an active fragment thereof, .whereby the nucleic acid is expressed in the patient to produce A3 or the active fragment thereof, which induces the immune response.

30. The method of claim 29, wherein the nucleic acid is administered through the skin.

31. The method of claim 30, wherein the nucleic acid is applied to the skin by a patch. .32. The method of any of the preceding claims, further IF-, comprising monitoring the patient for the immune response.

33. The method of any of the preceding claims, further comprising administering an adjuvant that enhances the immune response to the A peptide.

34. The method of claim 33, wherein the adjuvant and the agent are administered together as a composition. The method of claim 33, wherein the-adjuvant is administered before the agent.

36. The method of claim 33, wherein the adjuvant is administered after the agent.

37. The method of any one of claims 33-36, wherein the adjuvant is alum.

38. The method of any one of claims 33-36, wherein the adjuvant is MPL.

39. The method of any one of claims 33-36, wherein the adjuvant is QS21. The method of anyone of claims 33-36, wherein the dose of A6 peptide is greater than 10 pg.

41. A method of preventing or treating Alzheimer's disease comprising administering an effective dose of A,8 peptide to a patient.

42. Use of A, peptide, or an antibody thereto, in the manufacture of a medicament for prevention or treatment of Alzheimer's disease.

43. The use of claim 42, wherein the A3 peptide is combined with a pharmaceutically acceptable adjuvant in the manufacture of the medicament.

44. A composition comprising A/8 or a fragment linked to a conjugate molecule that promotes delivery of A,3 to the bloodstream of a patient and/or promotes an immune response against A3. The composition of claim 44, wherein the conjugates promotes an immune response against A,3.

46. The composition of claim 44 or 45, wherein the conjugate is cholera toxin.

47. The composition of claim 44 or 45, wherein the conjugate is an immunoglobulin.

48. The composition of claim 44 or 45, wherein the conjugate is attenuated diphtheria toxin CRM 197. ND 49. A pharmaceutical composition comprising an agent effect to induce an immunogenic response against A3 in a patient with the proviso that the composition is free of SComplete Freund's adjuvant. C0 5 50. A composition comprising a viral vector encoding A43 or 00 a fragment thereof effective to induce an immune response against A3. IN

51. A composition of claim 50, wherein the viral vector is herpes, adenovirus, adenoassociated virus, a retrovirus, sindbis, semiliki forest virus, vaccinia or avian pox.

52. A method of assessing efficacy of an Alzheimer's treatment method in a patient, comprising determining a baseline amount of antibody specific for A0 peptide in tissue sample from the patient before treatment IS with an agent, comparing an amount of antibody specific for A6 peptide in the tissue sample from the patient after treatment with the agent to the baseline amount of A3 peptide-specific antibody, wherein an amount of AO peptide-specific antibody .measured after the treatment that is significantly greater than the baseline amount of A3 peptide-specific antibody indicates a positive treatment outcome. IND 53. The method of claim 52, wherein the amounts of antibody are measured as antibody titers. (N S54. The method of claim 53, wherein the amounts of antibody are measured by an ELISA assay. 00 (N 55. A method of assessing efficacy of an Alzheimer's Streatment method in a patient, comprising determining a baseline amount of antibody specific for Al peptide in tissue sample from a patient before treatment with an agent; comparing an amount of antibody specific for AfS peptide in the tissue sample from the subject after treatment with the agent to the baseline amount of A,3 peptide-specific antibody, wherein a reduction or lack of significant difference between the amount of A peptide-specific antibody measured IS after the treatment compared to the baseline amount of Al peptide-specific antibody indicates a negative treatment outcome.

56. A method of assessing efficacy of an Alzheimer's treatment method in a patient, comprising C determining a control amount of antibody specific for A4 peptide in tissue samples from a control population, comparing an amount of antibody specific for A,3 peptide in a tissue sample from the patient after administering an agent to the control amount of A peptide-specific antibody, IND wherein an amount of A3 peptide-specific antibody measured O after the treatment that is significantly greater than the C<I control amount of AO peptide-specific antibody indicates a Spositive treatment outcome. h 57. A method of assessing efficacy of an Alzheimer's 00 treatment method in a patient, comprising determining a control amount of antibody specific for AP Speptide in tissues samples from a control population, comparing an amount of antibody specific for AS peptide in a tissue sample from the patient after administering an agent to said control amount of AO peptide-specific antibody, wherein a lack of significant difference between the amount of A/ peptide-specific antibody measured after beginning said treatment compared to the control amount of A4 peptide-specific antibody indicates a negative treatment outcome. .58. A method of monitoring Alzheimer's disease or susceptibility thereto in a patient, comprising: detecting an immune response against AO peptide in a sample -o from the patient.

59. The method of claim 58, wherein the patient is being administered an agent effective to treat or prevent Alzheimer's disease, and the level of the response determines the future treatment regime of the patient. CN 60. The method of claim 59, wherein the agent is AO peptide. C0 61. The method of any one of claims 57-60, wherein the 00 detecting comprises detecting an antibody that specifically binds to AO peptide. IN

62. The method of any one of claims 57-60, wherein the detecting comprises detecting T-cells specifically reactive with AO peptide.

63. A method of assessing efficacy of an Alzheimer's I0 treatment method in a patient, comprising determining a value for an amount of antibody specific for A,6 peptide in tissue sample from a patient who has been treated with an agent; comparing the value with a control value determined from a population of patient experiencing amelioriation of, or freedom from, symptoms of Alzheimer's disease due to treatment with the agent; wherein a value in the patient at least equal to the control value indicates a positive response to treatment. a> a> oo (N O CD <D 0q

64. Use of AO peptide in monitoring treatment of Alzheimer's disease in a patient. A diagnostic kit for monitoring treatment of Alzheimer's disease, comprising: -5 an agent that binds to antibodies specific for A3 peptide.

66. The diagnostic kit of claim 65, further comprising labelling indicating how the kit is used for moAitoring treatment of Alzheimer's disease. Dated 6 July, 2006 Neuralab Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON