The invention provides compositions and methods for treatment of amyloidogenic diseases. Such methods entail administering an agent that induces a beneficial immune response against an amyloid deposit in the patient. The methods are particularly useful for prophylactic and therapeutic treatment of Alzheimer's disease. In such methods, a suitable agent is Aβ peptide or an antibody thereto.

BACKGROUND OF THE INVENTION

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 60 years. In both types of disease, the pathology is the same but the βnormalities 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 μm 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.

The principal constituent of the plaques is a peptide termed Aβ or β-amyloid peptide. Aβ peptide is an internal fragment of 39-43 amino acids of a precursor protein termed amyloid precursor protein (APP). Several mutations within the APP protein have been correlated with the presence of Alzheimer's disease. See, e.g., Goate et al., Nature 349, 704) (1991) (valine⁷¹⁷ to isoleucine); Chartier Harlan et al. Nature 353, 844 (1991)) (valine⁷¹⁷ to glycine); Murrell et al., Science 254, 97 (1991) (valine⁷¹⁷ to phenylalanine); Mullan et al., Nature Genet. 1, 345 (1992) (a double mutation changing lysine⁵⁹⁵-methionine⁵⁹⁶ to asparagine⁵⁹⁵-leucine⁵⁹⁶). Such mutations are thought to cause Alzheimer's disease by increased or altered processing of APP to Aβ, particularly processing of APP to increased amounts of the long form of Aβ (i.e., Aβ1-42 and Aβ1-43). 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 Aβ (see Hardy, TINS 20, 154 (1997)). These observations indicate that Aβ, and particularly its long form, is a 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 Aβ 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 Aβ 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 Aβ 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 Aβ 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 immunogen or passive by administration of an antibody or an active fragment or derivative of the antibody. In some patients, the amyloid deposit is aggregated Aβ peptide and the disease is Alzheimer's disease. In some methods, the patient is asymptomatic. 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 Aβ peptide to the patient to induce the immune response. In some methods, the Aβ peptide is administered with an adjuvant that enhances the immune response to the Aβ peptide. In some methods, the adjuvant is alum. In some methods, the adjuvant is MPL. The dose of Aβ peptide administered to the patient is typically at least 1 or 10 μg, if administered with adjuvant, and at least 50 μg if administered without adjuvant. In some methods, the dose is at least 100 μg.

In some methods, the Aβ peptide is Aβ1-42. In some methods, the Aβ peptide is administered in aggregated form.

In other methods, the Aβ peptide is administered in dissociated form. In some methods, the therapeutic agent is an effective dose of a nucleic acid encoding Aβ or an active fragment or derivative thereof. The nucleic acid encoding Aβ or fragment thereof is expressed in the patient to produce Aβ 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 library of compounds to identify a compound reactive with antibodies to Aβ, and administering the compound to the patient to induce the immune response.

In some methods, the immune response is directed to aggregated Aβ peptide without being directed to dissociated Aβ peptide. For example, the immune response can comprise antibodies that bind to aggregated Aβ peptide without binding to dissociated Aβ peptide. In some methods, the immune response comprises T-cells that bind to Aβ complexed with MCH1 or MHCII on CD8 or CD4 cells. In other methods, the immune response is induced by administering an antibody to Aβ to the patient. In some methods, the immune response is induced by removing T-cells from the patient, contacting the T-cells with Aβ 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 Aβ 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 Aβ in a patient, and a pharmaceutically acceptable adjuvant. In some such compositions, the agent is Aβ 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 Aβ or active fragment is a component of a polylactide polyglycolide copolymer (PLPG) or other particle. The invention further provides compositions comprising Aβ or an active fragment linked to a conjugate molecule that promotes delivery of Aβ to the bloodstream of a patient and/or promotes an immune response against Aβ. For example, the conjugate can serve to promote an immune response against Aβ. In some compositions, the conjugate is cholera toxin. In some compositions, the conjugate is an immunoglobulin. In some compositions, the conjugate is attenuated diphtheria toxin CRM 197 (Gupta, Vaccine 15, 1341-3 (1997).

The invention also provides pharmaceutical compositions comprising an agent effect to induce an immunogenic response against Aβ in a patient with the proviso that the composition is free of Complete Freund's adjuvant. The invention also provides compositions comprising a viral vector encoding Aβ or a an active fragment thereof effective to induce an immune response against Aβ. 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 Aβ peptide is administered to a patient. The invention further provides for the use of Aβ, 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 Aβ peptide is determined in a tissue sample from the patient before treatment with an agent. An amount of antibody specific for Aβ peptide in the tissue sample from the patient after treatment with the agent is compared to the baseline amount of Aβ peptide-specific antibody. An amount of Aβ peptide-specific antibody measured after the treatment that is significantly greater than the baseline amount of Aβ 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 Aβ peptide in a tissue sample from a patient before treatment with an agent is determined. An amount of antibody specific for Aβ peptide in the tissue sample from the subject after treatment with the agent is compared to the baseline amount of Aβ peptide-specific antibody. A reduction or lack of significant difference between the amount of Aβ peptide-specific antibody measured after the treatment compared to the baseline amount of Aβ peptide-specific antibody indicates a negative treatment outcome.

In other methods of assessing efficacy of an Alzheimer's disease treatment method in a patient a control amount of antibody specific for Aβ peptide is determined in tissue samples from a control population. An amount of antibody specific for Aβ peptide in a tissue sample from the patient after administering an agent is compared to the control amount of Aβ peptide-specific antibody. An amount of Aβ peptide-specific antibody measured after the treatment that is significantly greater than the control amount of Aβ 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 Aβ peptide in tissues samples from a control population is determined. An amount of antibody specific for Aβ peptide in a tissue sample from the patient after administering an agent is compared to the control amount of Aβ peptide-specific antibody. A lack of significant difference between the amount of Aβ peptide-specific antibody measured after beginning said treatment compared to the control amount of Aβ 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 Aβ 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 Aβ peptide in tissue sample from a patient who has been treated with an agent is determined. The value 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.
 

Claim 1 of 63 Claims

1. A method of therapeutically treating a disease characterized by an amyloid deposit of Aβ in a patient, comprising:

administering an immunogenic Aβ fragment in a regime effective to induce an immune response comprising antibodies to the Aβ fragment and thereby therapeutically treat the disease in the patient; and

monitoring the patient for the immune response, wherein the monitoring comprises detecting antibodies having Aβ binding specificity.

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