|
|
Title:
Methods of inhibiting amyloid toxicity
United States Patent: 7,517,525
Issued: April 14, 2009
Inventors: Prenner; Irene
Griswald (Brisbane, CA), Wright; Sarah (San Francisco, CA), Yednock;
Theodore (Forest Knolls, CA), Rydel; Russell (Belmont, CA)
Assignee: Elan
Pharmaceuticals, Inc. (San Francisco, CA)
Appl. No.: 10/190,548
Filed: July 9, 2002
|
|
|
Web Seminars -- Pharm/Biotech/etc.
|
Abstract
The present invention features methods
and compositions for inhibiting amyloidogenic protein toxicity, inhibiting
formation of an amyloidogenic protein deposit and/or treating
amyloidogenic diseases by administering a pharmaceutically effective
amount of one or more agents that bind an integrin or an integrin subunit.
Description of the
Invention
A. General
The invention provides methods of inhibiting or preventing formation of
extracellular meshworks of amyloid proteins, such as amylin and A.beta.
peptide, methods for mediating the toxic effects of such proteins, and
agents for use in the methods. The methods can be used to treat or prevent
Alzheimer's disease, type II diabetes, Parkinson's disease, systemic and
hereditary amyloidoses, as well as diseases caused all or in part by prion
infection. Agents effective for use in these methods include antibodies and
other agents that bind to an integrin subunit such as .beta.1, .alpha.2,
.alpha.6, or .alpha.v. These subunits associate as heterodimeric receptors
to form integrins, e.g., .alpha.2.beta.1, .alpha.6.beta.1, and
.alpha.v.beta.1. The above agents can be used individually or in
combinations to inhibit interaction between integrins and the A.beta.
peptide. Use of an agent or agents that inhibit interactions between both
.alpha.v.beta.1 and .alpha.2.beta.1 integrins and A.beta. is preferred.
Fibronectin, a ligand of integrin, .alpha.v.beta.1, can also be used as an
agent, as can antibodies to laminin, a ligand of .alpha.v.beta.1 in the
above methods.
The invention is premised, in part, on the observation that antibodies to
.alpha.2, .alpha.v, .alpha.6 and .beta.1 integrin subunits inhibit formation
of extracellular meshworks of amyloid proteins, such as amylin and A.beta.
peptide. Thereby, such antibodies inhibit the toxicity of amyloid proteins.
The .alpha.v.beta.1 ligand, fibronectin, also inhibits meshwork formation.
The .alpha.2.beta.1 ligand, laminin, does not inhibit meshwork formation but
antibodies to laminin do inhibit meshwork formation and toxicity.
B. Integrins
Integrins are a superfamily of cell surface adhesion heterodimeric
transmembrane receptors, which control the attachment of cells both to the
extracellular matrix and to other cells. Adhesion provides anchorages and
signals for growth, migration, and differentiation. Integrins are formed by
the association of one of about fifteen known alpha chains with one of about
eight known beta chains. All human cells but erythrocytes express one or
more integrins.
Integrin subunits .alpha.2, .alpha.v, .alpha.6 and .beta.1 are all well
known. Exemplary human sequences are retrievable from GenBank accession
numbers AF062039, M14648, X59512 and X07979, respectively. Unless otherwise
indicated, reference to .alpha.2, .alpha.v, .alpha.6, .beta.1 includes these
exemplary sequences, allelic variants thereof, and cognate variants from
other species. Induced variants of these sequences, having sufficient
sequence identity to the natural sequence to compete with the natural
sequence for specific binding to a ligand of the natural sequence, can also
be used in some methods. Integrins containing .alpha.v and one of the .beta.
subunits .beta.1, .beta.3, .beta.5, .beta.6 or .beta.8 recognize ligands
bearing an RGD motif, but the binding specificity varies depending on which
.beta. subunit is present. .alpha.v.beta.1 is known to recognize vitronectin
(GenBank accession number X03168), fibronectin (GenBank accession number
M26179) and osteopontin (GenBank accession number J04765). Fibronectin is a
large multidomain glycoprotein found in connective tissue, on cell surfaces,
and in plasma and other body fluids. Fibronectin acts with a variety of
macromolecules, including components of the cytoskeleton and the
extracellular matrix, circulating components involved in the blood clotting
response, fibrinolytic, acute phase and complement systems, and with
cell-surface receptors on a variety of cells including fibroblasts, neurons,
phagocytes, and bacteria.
Integrins containing .alpha.2 and .beta.1 subunits are known as VLA-2 (very
late activation antigen 2), GPIa-IIa (glycoprotein Ia-IIa on platelets), and
ECMRII (extracellular matrix receptor II). The .alpha.2.beta.1 integrins
bind collagen-I to VI, laminin and possibly fibronectin. The receptor is
expressed on B and T lymphocytes, platelets, fibroblasts, endothelial cells,
and melanoma cells, and specifically recognizes collagen and laminins as
ligands. Laminins are large, multi domain proteins with a common structural
organization. Laminin molecules have alpha, beta, and gamma chain subunits
joined together though a coiled coil domain. At least five alpha chains, two
beta chains, and three gamma chains are known, and at least twelve laminins
having different combinations of these chains have been reported (WO
00/66730). Laminin is found in extracellular matrices including plaques in
Alzheimer's disease (Murtomaki, et al., J. Neuro. Res., 32:261-73 (1992);
Bronfinan, et al., Int. J. Exp. Clin. Invest., 5:16-23 (1997); and Castillo,
et al., J. Neuro. Res., 62:451-62 (2000)). Collagen is the most abundant
protein in mammals and is the main fibrous component of skin, bone, tendon,
cartilage, and teeth. There are more than 23 known collagen genes (Adams et
al., Am. J. Respir. Cell. Molec. Biol., 1: 161-168 (1989)).
The .alpha.6.beta.1 integrin is expressed on platelets, lymphocytes,
monocytes, thymocytes, and epithelial cells, on which it functions as a
laminin receptor for laminin-1, laminin-2, and laminin-4 in vivo. It is also
a receptor for laminin-5, but not in vivo. For laminin-1, the binding site
has been localized in the E8 domain of this extracellular matrix molecule.
This receptor is also known as very late activation antigen 6 (VLA-6) and
glycoprotein Ic-IIa (GPIc-IIa on platelets).
Integrins are an example of a larger class of proteins known as adhesion
proteins that also includes selectins and immunoglobulin (Ig) superfamily
members (see Springer, Nature, 346:425 (1990); Osborn, Cell, 62:3 (1990);
Hynes, Cell, 69:11 (1992), which are incorporated by reference in their
entirety for all purposes). Antibodies and other agents that bind to
adhesion proteins or their ligands, and/or block interaction between the
two, can be screened for activity in preventing or inhibiting the
accumulation of A.beta. deposits in the methods of screening described
below. Examples of other selectins and their ligands suitable for screening
by the methods described below include integrins .alpha.2.beta.5,
.alpha.v.beta.5, .alpha.6.beta.5, .alpha.2.beta.6, .alpha.v.beta.6, and
.alpha.6.beta.6. Other ligands besides .alpha.2.beta.1 that bind to collagen
may also be screened.
C. Agents
Therapeutic agents of the invention include antibodies that specifically
bind to .alpha.2, .alpha.v, .alpha.6, and .beta.1 integrin subunits. Binding
can be assessed either with isolated integrin subunits or fragments thereof,
optionally immobilized to a solid phase, or with integrin subunits expressed
on the surface of cells. Often, binding is analyzed using cells expressing a
heterodimeric integrin. For example, if an agent binds to cells expressing
.alpha.2.beta.1 as the only integrin, then it can be concluded that the
agent binds to .alpha.2 or .beta.1 or to .alpha.2.beta.1 without binding to
either subunit alone. These possibilities can be distinguished by testing
binding of the same agent to cells bearing a different heterodimeric
integrin. For example, if the same agent specifically binds to cells bearing
.alpha.v.beta.1 as the only integrin present, then it is likely that the
agent is binding to the .beta.1 subunit. A variety of antibodies to integrin
and integrin subunits are commercially available, some of which are
described in the Examples.
Monoclonal or polyclonal antibodies can be used in the methods of the
invention. Preferred antibodies block interaction of these integrin subunits
with one or more of their natural ligands. That is, blocking antibodies to
.alpha.v.beta.1 block interaction of this integrin with fibronectin,
osteopontin and/or vitronectin. For example, the 14D9.F8 antibody described
by WO 99/37683 blocks binding of .alpha.v to fibronectin. Blocking
antibodies to .alpha.2.beta.1 block interaction of this integrin with
collagen or laminin. The capacity of an antibody or other agent to block can
be recognized by a simple assay in which cells expressing an integrin are
tested for adhesion to a plate coated with ligand in the presence or absence
of antibody (or other agent). A reduction of at least about 30%, 40%, 50%,
60%, 70%, 80%, 90%, or 100% of the amount of cells binding to the plate
identifies a blocking antibody (or other agent) when the antibody is present
in molar excess relative to the integrin. Further analyses of the blocking
capacity of the agent to other combinations of integrin subunits can
pinpoint which subunit of a heterodimeric integrin is being blocked. Binding
specificity of an antibody or other agent can also be determined by a
competition assay in which a test antibody competes with a reference
antibody known to have the desired epitope specificity for binding to an
integrin subunit or cells bearing the same. If the test and reference
antibodies compete, then they bind to the same epitope or epitopes
sufficiently proximal that binding of one antibody interferes with binding
of the other. In some embodiments, transfected cells express a single type
of integrin.
Some antibodies for use in the invention bind to only one type of integrin
subunit. Some antibodies specifically bind to two or more integrin subunits.
Some antibodies bind only when the subunits of an integrin are associated as
a heterodimeric integrin. For example, some antibodies bind to
.alpha.2.beta.1 without binding to either .alpha.2 or .beta.1 alone. Some
antibodies bind to .alpha.v.beta.1 without binding to either .alpha.v or
.beta.1 alone. Some antibodies bind to subunits both in free form and when
the subunit is a component of a heterodimeric integrin. Peptides and small
molecules that have the same binding specificity of the above antibodies can
also be used.
Other therapeutic agents for use in the invention include fibrinogen,
osteopontin, vitronectin, fragments thereof, and other natural or synthetic
peptides containing an RGD peptide motif that competes with fibrinogen or
vitronectin for binding to .alpha.v.beta.1. Small molecule mimetics that
compete with fibrinogen, vitronectin, or osteopontin for binding to
.alpha.v.beta.1 can also be used. Other therapeutic agents include
antibodies to laminin, and peptides and small molecules with the same
binding specificity.
Candidate therapeutic agents can be evaluated by performing one or more of
the following screens. Typically, agents are first evaluated for specific
binding to an integrin subunit, .alpha.2, .alpha.v, .alpha.6, or .beta.1,
and/or a heterodimeric integrin .alpha.2.beta.1, .alpha.v.beta.1
.alpha.6.beta.1, or laminin. Suitable agents typically bind with specific
affinities of at least 10.sup.7, 10.sup.8, 10.sup.9 or 10.sup.10 M.sup.-1.
Thereafter, candidates are optionally evaluated for a particular epitope
specificity. This can be determined by a competition assay with a reference
agent, by a functional plate blocking assay as described above, or by an
epitope mapping experiment in which an antibody or other agent is evaluated
by Western blotting or ELISA for its capacity to bind a series of deletion
mutants of an antigen. The smallest fragment to show specific binding to the
antibody or other agent defines the epitope of the antibody or other agent.
Alternatively, or additionally, candidate agents are evaluated for the
capacity to inhibit formation of extracellular meshworks of amyloid
peptides. Suitable agents typically reduce toxicity resulting from treatment
with amyloid peptides, such as amylin or A.beta., in the presence of an
agent relative to a control by at least about 10%, 20%, 30%, 40%, 50%, 60%,
70%, 80%, 90%, or 100% or more.
Candidate compounds can also be tested for prophylactic and therapeutic
efficacy in transgenic animals predisposed to an amyloidogenic disease. Such
animals include, for example, mice bearing a 717 mutation of APP described
by Games et al., supra, and mice bearing a 670/671 Swedish mutation of APP
such as described by McConlogue et al., U.S. Pat. No. 5,612,486; Hsiao et
al., Science, 274:99 (1996); Sturchler-Plerrat et al., Proc. Natl. Acad. Sci.
U.S.A., 94:13287-92 (1997); and Borchelt et al., Neuron, 19:939-45 (1997).
Agents showing activity in transgenic mice can then be evaluated in human
clinical trials. Exemplary formats for conducting human clinical trials in
Alzheimer's patients are described in WO 98/24678, which is incorporated
herein by reference.
A. Antibodies
1. General Characteristics of Immunoglobulins
The basic antibody structural unit is known to comprise a tetramer of
subunits. Each tetramer is composed of two identical pairs of polypeptide
chains, each pair having one "light" (about 25 kDa) and one "heavy" chain
(about 50-70 kDa). The amino-terminal portion of each chain includes a
variable region of about 100 to 110 or more amino acids primarily
responsible for antigen recognition. The carboxy-terminal portion of each
chain defines a constant region primarily responsible for effector function.
Light chains are classified as either kappa or lambda. Heavy chains are
classified as gamma, mu, alpha, delta, or epsilon, and define the antibody's
isotype as IgG, IgM, IgA, IgD, and IgE, respectively. Within light and heavy
chains, the variable and constant regions are joined by a "J" region of
about 12 or more amino acids, with the heavy chain also including a "D"
region of about 10 more amino acids. (See generally, Fundamental Immunology
(Paul, W., Ed., 2nd ed. Raven Press, N.Y., 1989), Ch. 7 (incorporated by
reference in its entirety for all purposes).
The variable regions of each light/heavy chain pair form the antibody
binding site. Thus, an intact antibody has two binding sites. Except in
bifunctional or bispecific antibodies, the two binding sites are the same.
The chains all exhibit the same general structure of relatively conserved
framework regions (FR) joined by three hypervariable regions, also called
complementarity determining regions or CDRs. The CDRs from the two chains of
each pair are aligned by the framework regions, enabling binding to a
specific epitope. From N-terminal to C-terminal, both light and heavy chains
comprise the domains FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. The
assignment of amino acids to each domain is in accordance with the
definitions of Kabat, Sequences of Proteins of Immunological Interest
(National Institutes of Health, Bethesda, Md., 1987 and 1991), or Chothia &
Lesk, J. Mol. Biol., 196:901-17 (1987); Chothia et al., Nature, 342:878-83
(1989).
2. Production of Nonhuman Antibodies
The production of nonhuman monoclonal antibodies, e.g., murine, guinea pig,
primate, rabbit, or rat, can be accomplished by, for example, immunizing the
animal with an integrin, subunits thereof, or fragments thereof, or with
cells bearing the integrin or a subunit thereof. Laminin can also be used as
an immunogen for generating antibodies to laminin. See Harlow & Lane,
Antibodies, A Laboratory Manual (Cold Spring Harbor Press, NY, 1988,
incorporated herein by reference for all purposes). Such an immunogen can be
obtained from a natural source, by peptide synthesis, or by recombinant
expression. Optionally, the immunogen can be administered fused or otherwise
complexed with a carrier protein, as described below. Optionally, the
immunogen can be administered with an adjuvant. Several types of adjuvant
can be used as described below. Complete Freund's adjuvant followed by
incomplete adjuvant is preferred for immunization of laboratory animals.
Rabbits, goats, sheep, or guinea pigs are typically used for making
polyclonal antibodies. Mice are typically used for making monoclonal
antibodies. Antibodies are screened for specific binding to the intended
integrin or subunit thereof, or other antigen such as laminin. Antibodies
can also be screened for the capacity to block binding of an integrin to its
ligand as described above. Other screening procedures described above can
also be conducted.
3. Chimeric and Humanized antibodies
Chimeric and humanized antibodies may have the same or similar binding
specificity and affinity as a mouse or other nonhuman antibody that provides
the starting material for construction of a chimeric or humanized antibody.
Some chimeric or humanized antibodies have affinities within a factor of
2-fold, 5-fold or 10-fold that of a mouse. Chimeric antibodies are
antibodies whose light and heavy chain genes have been constructed,
typically by genetic engineering, from immunoglobulin gene segments
belonging to different species. For example, the variable (V) segments of
the genes from a mouse monoclonal antibody may be joined to human constant
(C) segments, such as IgG1, IgG2, IgG3, or IgG4. A typical chimeric antibody
is thus a hybrid protein consisting of the V or antigen-binding domain from
a mouse antibody and the C or effector domain from a human antibody.
Humanized antibodies have variable region framework residues substantially
from a human antibody (termed an acceptor antibody) and complementarity
determining regions substantially from a nonhuman antibody such as a
mouse-antibody, (referred to as the donor immunoglobulin). See Queen et al.,
Proc. Nat. Acad. Sci. U.S.A., 86:10029-33 (1989) and WO 90/07861, U.S. Pat.
No. 5,693,762, U.S. Pat. No. 5,693,761, U.S. Pat. No. 5,585,089, U.S. Pat.
No. 5,530,101, and Winter, U.S. Pat. No. 5,225,539 (each of which are
incorporated herein by reference in their entirety for all purposes). The
constant region, if present, is also substantially or entirely from a human
immunoglobulin. The human variable domains are usually chosen from human
antibodies whose framework sequences exhibit a high degree of sequence
identity with the murine variable region domains from which the CDRs were
derived. The heavy and light chain variable region framework residues can be
derived from the same or different human antibody sequences. The human
antibody sequences can be the sequences of naturally occurring human
antibodies or can be consensus sequences of several human antibodies. See
Carter et al., WO 92/22653. Certain amino acids from the human variable
region framework residues are selected for substitution based on their
possible influence on CDR conformation and/or binding to antigen.
Investigation of such possible influences is by modeling, examination of the
characteristics of the amino acids at particular locations, or empirical
observation of the effects of substitution or mutagenesis of particular
amino acids.
For example, when an amino acid differs between a murine variable region
framework residue and a selected human variable region framework residue,
the human framework amino acid should usually be substituted by the
equivalent framework amino acid from the mouse antibody when it is
reasonably expected that the amino acid:
(1) noncovalently binds antigen directly,
(2) is adjacent to a CDR region,
(3) otherwise interacts with a CDR region (e.g., is within about 6 angstroms
of a CDR region), or
(4) participates in the VL-VH interface.
Other candidates for substitution are acceptor human framework amino acids
that are unusual for a human immunoglobulin at that position. These amino
acids can be substituted with amino acids from the equivalent position of
the donor antibody or from the equivalent positions of more typical human
immunoglobulins. The variable region frameworks of humanized immunoglobulins
usually show at least 85% sequence identity to a human variable region
framework sequence or consensus of such sequences.
4. Human Antibodies
Human antibodies against the above integrins or laminin are provided by a
variety of techniques described below. Some human antibodies are selected by
competitive binding experiments, or otherwise, to have the same epitope
specificity as a particular mouse antibody, such as one of the mouse
monoclonals described in the Examples. Human antibodies can also be screened
for a particular epitope specificity by using only a fragment of an integrin
or laminin as the immunogen, and/or by screening antibodies against a
collection of deletion mutants of the integrin.
a. Trioma Methodology
The basic approach and an exemplary cell fusion partner, SPAZ-4, for use in
this approach have been described by Oestberg et al., Hybridoma, 2:361-67
(1983); Oestberg, U.S. Pat. No. 4,634,664; and Engleman et al., U.S. Pat.
No. 4,634,666 (each of which is incorporated herein by reference in its
entirety for all purposes). The antibody-producing cell lines obtained by
this method are called triomas, because they are descended from three
cells--two human and one mouse. Initially, a mouse myeloma line is fused
with a human B-lymphocyte to obtain a nonantibody-producing xenogeneic
hybrid cell, such as the SPAZ-4 cell line described by Oestberg, supra. The
xenogeneic cell is then fused with an immunized human B-lymphocyte to obtain
an antibody-producing trioma cell line. Triomas have been found to produce
antibody more stably than ordinary hybridomas made from human cells.
The immunized B-lymphocytes are obtained from the blood, spleen, lymph
nodes, or bone marrow of a human donor. If antibodies against a specific
antigen or epitope are desired, it is preferable to use that antigen or an
epitope thereof for immunization. Immunization can be either in vivo or in
vitro. For in vivo immunization, B cells are typically isolated from a human
immunized with A.beta., a fragment thereof, larger polypeptide containing
A.beta. or fragment, or an anti-idiotypic antibody to an antibody to A. In
some methods, B cells are isolated from the same patient who is ultimately
to be administered antibody therapy. For in vitro immunization,
B-lymphocytes are typically exposed to antigen for a period of 7-14 days in
a medium such as RPMI-1640 (see Engleman, supra) supplemented with 10% human
plasma.
The immunized B-lymphocytes are fused to a xenogeneic hybrid cell such as
SPAZ-4 by well known methods. For example, the cells are treated with 40-50%
polyethylene glycol of MW 1000-4000, at about 37.degree. C., for about 5-10
min. Cells are separated from the fusion mixture and propagated in medium
selective for the desired hybrids (e.g., containing
Hypoxanthine+Amethopterin+Thymidine (HAT Media) or Amethopterin+Hypoxanthine
(AH Media)). Clones secreting antibodies having the required binding
specificity are identified by assaying the trioma culture medium for the
ability to bind to A.beta. or a fragment thereof. Triomas producing human
antibodies having the desired specificity are subcloned by the limiting
dilution technique and grown in vitro in culture medium. The trioma cell
lines obtained are then tested for the ability to bind A.beta. or a fragment
thereof.
Although triomas are genetically stable they do not produce antibodies at
very high levels. Expression levels can be increased by cloning antibody
genes from the trioma into one or more expression vectors, and transforming
the vector into standard mammalian, bacterial, or yeast cell lines.
b. Transgenic Non-Human Mammals
Human antibodies against integrins or laminin can also be produced from
non-human transgenic mammals having transgenes encoding at least a segment
of the human immunoglobulin locus. Usually, the endogenous immunoglobulin
locus of such transgenic mammals is functionally inactivated. Preferably,
the segment of the human immunoglobulin locus includes non-rearranged
sequences of heavy and light chain components. Both the inactivation of
endogenous immunoglobulin genes and the introduction of exogenous
immunoglobulin genes can be achieved by the targeted homologous
recombination, or by introduction of yeast artificial chromosomes (YACs).
The transgenic mammals resulting from this process are capable of
functionally rearranging the immunoglobulin component sequences, and
expressing a repertoire of antibodies of various isotypes encoded by human
immunoglobulin genes, without expressing endogenous immunoglobulin genes.
The production and properties of mammals having these properties are
described in detail by, e.g., Lonberg et al., WO93/12227 (1993); U.S. Pat.
No. 5,877,397, U.S. Pat. No. 5,874,299, U.S. Pat. No. 5,814,318, U.S. Pat.
No. 5,789,650, U.S. Pat. No. 5,770,429, U.S. Pat. No. 5,661,016, U.S. Pat.
No. 5,633,425, U.S. Pat. No. 5,625,126, U.S. Pat. No. 5,569,825, U.S. Pat.
No. 5,545,806, Nature 148, 1547-53 (1994), Fishwild et al., Nature
Biotechnology, 14, 845-51 (1996), Kucherlapati, WO 91/10741 (1991) (each of
which is incorporated by reference in its entirety for all purposes).
Transgenic mice are particularly suitable. Anti-integrin or anti-laminin
antibodies are obtained by immunizing a transgenic nonhuman mammal, such as
described by Lonberg or Kucherlapati, supra, with an integrin or subunit or
a fragment thereof. Monoclonal antibodies are prepared by, e.g., fusing
B-cells from such mammals to suitable myeloma cell lines using conventional
Kohler-Milstein technology. 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 affinity
purification using an integrin or laminin as an affinity reagent.
c. Phage Display Methods
A further approach for obtaining human anti-integrin or anti-laminin
antibodies is to screen a DNA library from human B cells according to the
general protocol outlined by Huse et al., Science, 246:1275-81 (1989). As
described for trioma methodology, such B cells can be obtained from a human
immunized with an integrin, subunits, or fragments thereof, or laminin and
fragments thereof. Optionally, such B cells are obtained from a patient who
is ultimately to receive antibody treatment. Antibodies binding to an
antigen of interest or a fragment thereof are selected. Sequences encoding
such antibodies (or binding fragments) are then cloned and amplified. The
protocol described by Huse is rendered more efficient in combination with
phage-display technology. See, e.g., Dower et al., WO 91/17271 and
McCafferty et al., WO 92/01047, U.S. Pat. No. 5,877,218, U.S. Pat. No.
5,871,907, U.S. Pat. No. 5,858,657, U.S. Pat. No. 5,837,242, U.S. Pat. No.
5,733,743, U.S. Pat. No. 5,565,332, U.S. Pat. No. 5,969,108, U.S. Pat. No.
6,172,197 (each of which is incorporated herein by reference in its entirety
for all purposes). Additional methods for selecting and labeling antibodies,
or other proteins, that bind to a particular ligand are described by U.S.
Pat. No. 5,994,519 and U.S. Pat. No. 6,180,336.
In phage display methods, libraries of phage are produced in which members
display different antibodies on their outer surfaces. Antibodies are usually
displayed as Fv or Fab fragments. Phage displaying antibodies with a desired
specificity are selected by affinity enrichment to an integrin, subunit, or
fragment thereof.
In a variation of the phage display method, human antibodies having the
binding specificity of a selected murine antibody can be produced. See
Winter, WO 92/20791. In this method, either the heavy or light chain
variable region of the selected murine antibody is used as a starting
material. If, for example, a light chain variable region is selected as the
starting material, a phage library is constructed in which members display
the same light chain variable region (i.e., the murine starting material)
and a different heavy chain variable region. The heavy chain variable
regions are obtained from a library of rearranged human heavy chain variable
regions. A phage showing strong specific binding for A.beta. (e.g., at least
about 10.sup.8 or at least about 10.sup.9 M.sup.-1) is selected. The human
heavy chain variable region from this phage then serves as the starting
material for constructing a further phage library. In this library, each
phage displays the same heavy chain variable region (i.e., the region
identified from the first display library) and a different light chain
variable region. The light chain variable regions are obtained from a
library of rearranged human variable light chain regions. Again, phage
showing strong specific binding for a desired integrin are selected. These
phage display the variable regions of completely human anti-integrin
antibodies. These antibodies usually have the same or similar epitope
specificity as the murine starting material.
5. Selection of Constant Region
The heavy and light chain variable regions of chimeric, humanized, or human
antibodies can be linked to at least a portion of a human constant region.
The choice of constant region depends, in part, on whether
antibody-dependent complement and/or cellular mediated toxicity is desired.
For example, isotypes IgG1 and IgG3 have complement activity and isotypes
IgG2 and IgG4 do not. Choice of isotype can also affect passage of the
antibody into the brain. Light chain constant regions can be lambda or
kappa. Antibodies can be expressed as tetramers containing two light and two
heavy chains, as separate heavy chains, light chains, as Fab, Fab', F(ab').sub.2,
and Fv, or as single chain antibodies in which heavy and light chain
variable domains are linked through a spacer.
6. Expression of Recombinant Antibodies
Chimeric, humanized, and human antibodies are typically produced by
recombinant expression. Recombinant polynucleotide constructs typically
include an expression control sequence operably linked to the coding
sequences of the antibody chains, including naturally-associated or
heterologous promoter regions. Preferably, the expression control sequences
are eukaryotic promoter systems in vectors capable of transforming or
transfecting eukaryotic host cells. Once the vector has been incorporated
into the appropriate host, the host is maintained under conditions suitable
for high level expression of the nucleotide sequences and for the collection
and purification of the crossreacting antibodies.
These expression vectors typically replicate in the host organisms either as
episomes or as an integral part of the host chromosomal DNA. Commonly,
expression vectors contain selection markers, e.g., ampicillin-resistance or
hygromycin-resistance, to permit detection of those cells transformed with
the desired DNA sequences.
Escherichia coli is one prokaryotic host particularly useful for cloning the
DNA sequences of the present invention. Microbes, such as yeast are also
useful for expression. Saccharomyces is a preferred yeast host, with
suitable vectors having expression control sequences, an origin of
replication, termination sequences and the like as desired. Typical
promoters include the 3-phosphoglycerate kinase promoter and promoters from
other glycolytic enzymes. Inducible yeast promoters include, among others,
the promoters from alcohol dehydrogenase, isocytochrome C, and the enzymes
responsible for maltose and galactose utilization.
Mammalian cells are a preferred host for expressing nucleotide segments
encoding immunoglobulins, or fragments thereof. See Winnacker, From Genes to
Clones, (VCH Publishers, NY, 1987). A number of suitable host cell lines
capable of secreting intact heterologous proteins have been developed in the
art, and include CHO cell lines, various COS cell lines, HeLa cells, L
cells, and myeloma cell lines. Preferably, the cells are nonhuman.
Expression vectors for these cells can include expression control sequences,
such as an origin of replication, a promoter, an enhancer (Queen et al.,
Immunol. Rev., 89:49-68 (1986)), and necessary processing information sites,
such as ribosome binding sites, RNA splice sites, polyadenylation sites, and
transcriptional terminator sequences. Preferred expression control sequences
are promoters derived from endogenous genes, cytomegalovirus, SV40,
adenovirus, bovine papillomavirus, and the like. See Co et al., J. Immunol.,
148:1149-54 (1992).
Alternatively, antibody coding sequences can be incorporated in transgenes
for introduction into the genome of a transgenic animal and subsequent
expression in the milk of the transgenic animal (see, e.g., U.S. Pat. No.
5,741,957, U.S. Pat. No. 5,304,489, U.S. Pat. No. 5,849,992). Suitable
transgenes include coding sequences for light and/or heavy chains in
operable linkage with a promoter and enhancer from a mammary gland specific
gene, such as casein or beta lactoglobulin.
The vectors containing the DNA segments of interest can be transferred into
the host cell by well-known methods, depending on the type of cellular host.
For example, calcium chloride transfection is commonly utilized for
prokaryotic cells, whereas calcium phosphate treatment, electroporation,
lipofection, biolistics, or viral-based transfection can be used for other
cellular hosts. Other methods used to transform mammalian cells include the
use of polybrene, protoplast fusion, liposomes, and microinjection. For
production of transgenic animals, transgenes can be microinjected into
fertilized oocytes, or can be incorporated into the genome of embryonic stem
cells, and the nuclei of such cells transferred into enucleated oocytes.
Once expressed, antibodies can be purified according to standard procedures
known in the art, including HPLC purification, column chromatography, gel
electrophoresis, and the like (see generally, Scopes, Protein Purification
(Springer-Verlag, NY, 1982)).
B. Other Agents
Agents can be naturally occurring or synthetic molecules. Agents to be
screened can also be obtained from natural sources, such as, e.g., marine
microorganisms, algae, plants, and fungi. For example, U.S. Pat. No.
6,096,707, provides peptides derived from jararhagin, a metalloproteinase
from the pit viper Bothrops jararaca. These peptides contain the amino acid
motif Arg-Lys-Lys (RKK), and decrease the interaction of the human
.alpha.2.beta.1 integrin with collagen. Alternatively, agents to be screened
can be from combinatorial libraries of agents, including peptides or small
molecules, or from existing repertories of chemical compounds synthesized in
industry, e.g., by the chemical, pharmaceutical, environmental,
agricultural, marine, cosmeceutical, drug, and biotechnological industries.
Agents can include, e.g., pharmaceuticals, therapeutics, environmental,
agricultural, or industrial agents, pollutants, cosmeceuticals, drugs,
organic compounds, lipids, glucocorticoids, antibiotics, peptides, proteins,
sugars, carbohydrates, and chimeric molecules.
A variety of methods are available for producing peptide libraries (see,
e.g., Lam et al., Nature, 354:92, 1991 and WO 92/00091; Geysen et al., J.
Immunol. Meth., 102:259 (1987); Houghten et al., Nature, 354:84 (1991); WO
92/09300; and Lebl et al., Int. J. Pept. Prot. Res., 41:201 (1993)). Peptide
libraries can also be generated by phage display methods. See, e.g., Devlin,
WO 91/18980.
Combinatorial libraries can be produced for many types of compounds that can
be synthesized in a step-by-step fashion (see e.g., Ellman & Bunin, J. Amer.
Chem. Soc., 114:10997, 1992 (benzodiazepine template), WO 95/32184 (oxazolone
and aminidine template), WO 95/30642 (dihydrobenzopyran template), and WO
95/35278 (pyrrolidine template)). Libraries of compounds are usually
synthesized by solid phase chemistry. However, solution-phase library
synthesis can also be useful. Strategies for combinatorial synthesis are
described by Dolle & Nelson, J. Combinatorial Chemistry, 1:235-282 (1999)
(incorporated herein by reference in its entirety for all purposes).
Synthesis is typically performed in a cyclic fashion with a different
monomer or other component being added in each round of synthesis. Some
methods are performed by successively fractionating an initial pool. For
example, a first round of synthesis is performed on all supports. The
supports are then divided into two pools and separate synthesis reactions
are performed on each pool. The two pools are then further divided, each
into a further two pools and so forth. Other methods employ both splitting
and repooling. For example, after an initial round of synthesis, a pool of
compounds is split into two for separate syntheses in a second round.
Thereafter, aliquots from the separate pools are recombined for a third
round of synthesis. Split and pool methods result in a pool of mixed
compounds. These methods are particularly amenable for tagging as described
in more detail below. The size of libraries generated by such methods can
vary from 2 different compounds to 10.sup.6, or 10.sup.10, or any range
there between.
Preparation of encoded libraries is described in a variety of publications
including Needels, et al., Proc. Natl. Acad. Sci. U.S.A., 90:10700 (1993);
Ni, et al., J. Med. Chem., 39:1601 (1996), WO 95/12608, WO 93/06121, WO
94/08051, WO 95/35503, and WO 95/30642 (each of which is incorporated herein
by reference in its entirety for all purposes). Methods for synthesizing
encoded libraries typically involve a random combinatorial approach and the
chemical and/or enzymatic assembly of monomer units. For example, the method
typically includes steps of: (a) apportioning a plurality of solid supports
among a plurality of reaction vessels; (b) coupling to the supports in each
reaction vessel a first monomer and a first tag using different first
monomer and tag combinations in each different reaction vessel; (c) pooling
the supports; (d) apportioning the supports among a plurality of reaction
vessels; (e) coupling to the first monomer a second monomer and coupling to
either the solid support or to the first tag a second tag using different
second monomer and second tag combinations in each different reaction
vessel; and optionally repeating the coupling and apportioning steps with
different tags and different monomers one to twenty or more times. The
monomer set can be expanded or contracted from step to step; or the monomer
set could be changed completely for the next step (e.g., amino acids in one
step, nucleosides in another step, carbohydrates in another step). A monomer
unit for peptide synthesis, for example, can include single amino acids or
larger peptide units, or both.
Compounds synthesizable by such methods include polypeptides, beta-turn
mimetics, polysaccharides, phospholipids, hormones, prostaglandins,
steroids, aromatic compounds, heterocyclic compounds, benzodiazepines,
oligomeric N-substituted glycines, and oligocarbamates. Prepared
combinatorial libraries are also available from commercial sources (e.g.,
ChemRx, South San Francisco, Calif.).
Combinatorial libraries and other compounds are initially screened for
suitability by determining their capacity to bind to .alpha.2.beta.1,
.alpha.6.beta.1, or .alpha.v.beta.1 integrins, or to laminin. The additional
screening procedures described above can also be used.
C. Gene Suppression Agents
Agents that suppress gene expression can be used to suppress the expression
of genes encoding integrin subunits .beta.1, .alpha.2, .alpha.6 or .alpha.v.
Antisense agents can also be used to suppress expression of certain ligands
thereto, such as laminin. Suppression of laminin expression can achieve
similar effects to treatment with antibodies against laminin. Administration
of the antisense reagents of the invention to a target cell or patient
results in reduced activity of one of the above integrin genes or its ligand.
For general methods relating to antisense polynucleotides, see, e.g.,
Antisense RNA and DNA, (1988), D. A. Melton, Ed., Cold Spring Harbor
Laboratory, Cold Spring Harbor, N.Y.); Dagle et al., Nucleic Acids Research,
19:1805 (1991); Uhlmann et al., Chem. Reviews, 90:543-584 (1990). Ribozymes
are another antisense agent that can suppress gene expression.
Antisense oligonucleotides can cause suppression by binding to, and
interfering with the translation of sense mRNA, rendering mRNA susceptible
to nuclease digestion, interfering with transcription, interfering with the
processing or localization of RNA precursors, repressing the transcription
of mRNA, or acting through some other mechanism. The particular mechanism by
which the antisense molecule reduces expression is not critical.
Typically antisense polynucleotides comprise an antisense sequence of at
least 7 to 10 to typically 20 or more nucleotides that specifically
hybridize to a sequence from an mRNA of a gene. Some antisense
polynucleotides are from about 10 to about 50 nucleotides in length or from
about 14 to about 35 nucleotides in length. Some antisense polynucleotides
are polynucleotides of less than about 100 nucleotides or less than about
200 nucleotides. In general, the antisense polynucleotide should be long
enough to form a stable duplex, but short enough, depending on the mode of
delivery, to administer in vivo, if desired. The minimum length of a
polynucleotide required for specific hybridization to a target sequence
depends on several factors, such as the G/C content, the positioning of
mismatched bases (if any), the overall differences of the sequence relative
to the population of target polynucleotides, and the chemical nature of the
polynucleotide (e.g., methylphosphonate backbone, peptide nucleic acid,
phosphorothioate), among other factors.
Suitable conditions for hybridizing complementary nucleic acid molecules are
well known to those of skill in the art. For example, hybridization under
typical high stringency conditions may be performed in a mixture containing
5.times.SSPE, 5.times. Denhart solution, 0.5% SDS (w/v), and 100 .mu.g/ml
salmon sperm DNA. The DNA is allowed to hybridize for a specified period of
time at about 68.degree. C. The hybridized DNA, which is typically bound to
a membrane or filter, is then washed 2 times for 10 minutes, in
2.times.SSPE, 0.1% SDS (w/v) at room temperature. The membrane (or filter)
is then immersed in a solution of 1.times.SSPE, 0.1% SDS (w/v) for 15
minutes at 68.degree. C., and finally in a solution of 1.times.SSPE, 0.1%
SDS (w/v) for 15 minutes at 68.degree. C.
To ensure specific hybridization, the antisense sequence is at least
substantially complementary to the target mRNA or gene encoding the same.
Some antisense sequences are exactly complementary to their intended target
sequence. The antisense polynucleotides can also include, however,
nucleotide substitutions, additions, deletions, transitions, transpositions,
or modifications, or other nucleic acid sequences or non-nucleic acid
moieties so long as specific binding to the relevant target sequence
corresponding to the RNA or its gene is retained as a functional property of
the polynucleotide.
Some antisense sequences are complementary to relatively accessible
sequences of mRNA (e.g., relatively devoid of secondary structure). This can
be determined by analyzing predicted RNA secondary structures using, for
example, the MFOLD program (Genetics Computer Group, Madison Wis.) and
testing in vitro or in vivo as is known in the art. Another useful method
for identifying effective antisense compositions uses combinatorial arrays
of oligonucleotides (see, e.g., Milner et al., Nature Biotechnology, 15:537
(1997).
One technique to inhibit gene expression involves the introduction of
double-stranded RNA, also referred to as inhibitory RNA (RNAi), into a cell.
The RNAi comprises two complementary strands of RNA (a sense strand and an
antisense strand) annealed to each other to form a double stranded RNA
molecule. The RNAi is typically derived from an exon or coding sequence of
the gene that is being targeted for inhibition. The RNAi results in the
destruction of mRNA complementary to the sequence of the RNAi molecule.
Examples of RNAi and their use in living organisms are described, for
example, by Fire et al., Nature, 391:806-811 (1998); Nykanen et al., Cell,
107:309-321 (2001); and in WO 01/29058, WO 01/75164, and WO 99/32619. In
some methods the RNAi is between about 100 bp and 1000 bp, for example,
about 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, or more base pairs.
In some methods the RNAi is derived from an exon. In other methods, the RNAi
is derived from an intron or signaling sequence.
In some methods, antisense polynucleotides have sequences in addition to the
antisense sequence, including promoters and other regulatory sequences that
result in expression of an antisense sequence. Provided that the promoter
and, preferably termination and polyadenylation signals, are properly
positioned, the strand of the inserted sequence corresponding to the
noncoding strand is transcribed and acts as an antisense oligonucleotide. In
some methods, the polynucleotide consists essentially of, or is, the
antisense sequence. The antisense nucleic acids (DNA, RNA, modified,
analogues, and the like) can be made using any suitable method for producing
a nucleic acid, such as the chemical synthesis and recombinant methods
disclosed herein. For example, antisense RNA molecules can be prepared by de
novo chemical synthesis or by cloning.
Zinc finger proteins can be used as an alternative or in addition to
antisense polynucleotides to suppress the expression of the genes encoding
the .beta.1, .alpha.2, .alpha.6 or .alpha.v integrin subunits. Zinc finger
proteins can also be used to suppress the expression of certain ligands of
these integrin subunits, such as laminin. Zinc finger proteins can also be
used to activate or enhance the expression of other ligands, such as
fibronectin, that can themselves be used as agents in the present methods.
Zinc finger proteins can be engineered or selected to bind to any desired
target site within a target gene. In some methods, the target site is within
a promoter or enhancer. In other methods, the target site is within the
structural gene. In some methods, the zinc finger protein is linked to a
transcriptional repressor, such as the KRAB repression domain from the human
KOX-1 protein (Thiesen et al., New Biologist, 2, 363-374 (1990); Margolin et
al., Proc. Natl. Acad. Sci. U.S.A., 91, 4509-4513 (1994)); Pengue et al.,
Nucl. Acids Res., 22:2908-2914 (1994); Witzgall et al., Proc. Natl. Acad.
Sci. U.S.A., 91, 4514-4518 (1994). Preferred domains for achieving
activation include the HSV VP16 activation domain (see, e.g., Hagmann et
al., J. Virol., 71:5952-5962 (1997)) nuclear hormone receptors (see, e.g.,
Torchia et al., Curr. Opin. Cell. Biol., 10:373-383 (1998)); the p65 subunit
of nuclear factor kappa B (Bitko & Barik, J. Virol., 72:5610-5618 (1998) and
Doyle & Hunt, Neuroreport, 8:2937-2942 (1997)); Liu et al., Cancer Gene Ther.,
5:3-28 (1998)), or artificial chimeric functional domains such as VP64 (Seifpal
et al., EMBO J., 11:4961-4968 (1992)). Methods for selecting target sites
suitable for targeting by zinc finger proteins, and methods for designing
zinc finger proteins to bind to selected target sites are described in WO
00/00388. Methods for selecting zinc finger proteins to bind to a target
using phage display are described by EP 95908614A. Methods for using zinc
finger proteins to regulate endogenous genes are described in WO 00/00409.
Zinc finger proteins can be administered either as proteins or in the form
of nucleic acids encoding zinc fingers and having appropriate regulatory
sequences.
D. Nucleic Acids Encoding Therapeutic Agents
Antibody or other peptide reagents can be administered in the form of
nucleic acids encoding antibody chains or peptides. Such nucleic acids are
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. Promoter and enhancer elements from light or heavy chain
immunoglobulin genes or the cytomegalovirus (CMV) major intermediate early
promoter and enhancer are suitable to direct expression. In some methods
promoters that cause expression in the brain are used. Promoters such as
platlet-derived growth factor (PDGF), prion, or the neural enolase promoter
are suitable.
The linked regulatory elements and coding sequences are often cloned into a
vector. For administration of double-chain antibodies, the two chains can be
cloned in the same or separate vectors.
A number of viral vector systems are available including retroviral systems
(see, e.g., Lawrie and Tumin, Curr. Opin. Genet. Develop., 2:102-109
(1993)); adenoviral vectors (see, e.g., Bett et al., J. Virol., 67:5911
(1993)); adeno-associated virus vectors (see, e.g., Zhou et al., J. Exp.
Med., 179:1867-75 (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,
e.g., Dubensky et al., J. Virol., 70:508-19 (1996)), Venezuelan equine
encephalitis virus (see U.S. Pat. No. 5,643,576), rhabdoviruses, such as
vesicular stomatitis virus (see WO 96/34625), and papillomaviruses (Ohe et
al., Human Gene Therapy, 6:325-33 (1995); Woo et al., WO 94/12629; and Xiao
& Brandsma, Nucleic Acids. Res., 24:2630-22 (1996)).
DNA can be packaged into liposomes. Suitable lipids and related analogs are
described by U.S. Pat. No. 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, polylactides, and poly(lactide-co-glycolides).
Gene therapy vectors or naked DNA can be delivered in vivo by administration
to an individual patient, typically by systemic administration (e.g.,
intravenous, intraperitoneal, nasal, gastric, intradermal, intramuscular,
intrathecal, subdermal, or intracranial infusion) or topical application
(see, e.g., U.S. Pat. No. 5,399,346). Such vectors can further include
facilitating agents such as bupivacine (U.S. Pat. No. 5,593,970). DNA can
also be administered using a gene gun. See Xiao & Brandsma, supra. The DNA
is precipitated onto the surface of microscopic metal beads. The
microprojectiles are accelerated with a shock wave or expanding helium gas,
and penetrate tissues to a depth of several cell layers. For example, the
Accel.TM. Gene Delivery Device manufactured by Agacetus, Inc., Middleton,
Wis. is suitable. Alternatively, naked DNA can pass through skin into the
blood stream simply by spotting the DNA onto skin with chemical or
mechanical irritation (see WO 95/05853).
In a further variation, nucleic acids can be delivered to cells ex vivo,
such as cells explanted from an individual patient (e.g., 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 that have incorporated the vector.
IV. Patients Amenable To Treatment
The present methods are useful for prophylactic or therapeutic treatment of
several amyloidogenic diseases and conditions that are characterized by the
presence of deposits of amyloid proteins, such as amylin or A.beta. peptide.
Such diseases include Alzheimer's disease, Down's syndrome and cognitive
impairment, type II diabetes, Parkinson's disease, amyloidoses such as
hereditary or systemic amyloidoses, and diseases caused all or in part by
prion infection.
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. The present methods are
especially useful for individuals who 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, for example 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, family
history of AD, hypercholesterolemia, or arteriosclerosis. Individuals
presently suffering from Alzheimer's disease can be recognized from
characteristic dementia, as well as the presence of the risk factors
described above. In addition, a number of diagnostic tests are available for
identifying individuals who have AD. These include measurement of
cerebrospinal fluid (CSF) tau and A.beta.42 levels. Elevated tau and
decreased A.beta.42 levels signify the presence of AD. Individuals suffering
from Alzheimer's disease can also be diagnosed by ADRDA criteria. In
asymptomatic patients, treatment can begin at any age (e.g., about 10, about
20, about 30). Usually, however, it is not necessary to begin treatment
until a patient reaches about 40, about 50, about 60, about 70, about 80 or
about 90. Treatment typically entails multiple dosages over a period of
time. In the case of Down's syndrome patients, treatment can begin
prenatally by administering therapeutic agents to the mother; or treatment
may begin shortly after birth.
V. Treatment Regimes
In prophylactic applications, pharmaceutical compositions or medicaments are
administered to a patient susceptible to, or otherwise at risk of developing
an amyloidogenic disease, in an amount sufficient to eliminate or reduce the
risk, lessen the severity, or delay the onset of the disease, including
biochemical, histological and/or behavioral symptoms of the disease, its
complications and intermediate pathological phenotypes presenting during
development of the disease.
In therapeutic applications, compositions or medicaments 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 (biochemical, histological, and/or behavioral), including its
complications and intermediate pathological symptoms. An amount adequate to
accomplish therapeutic or prophylactic treatment is defined as a
therapeutically- or prophylactically-effective dose. In therapeutic regimes,
the agent is usually administered at intervals until symptoms of the disease
disappear or significantly decrease. Optionally administration can be
continued to prevent recurrence. In prophylactic regimes, agents are also
usually administered at intervals, in some instances for the rest of a
patient's life. Treatment can be monitored by assaying levels of
administered agent, or by monitoring the response of the patient. The
response can be monitored by ADRDA criteria and imaging of plaques in the
brain of the patient (see WO 00/14810).
Effective doses of the compositions of the present invention, for the
treatment of the above-described conditions vary depending upon many
different factors, including means of administration, target site,
physiological state of the patient, whether the patient is human or an
animal, other medications administered, and whether treatment is
prophylactic or therapeutic. Usually, the patient is a human; nonhuman
mammals, including transgenic mammals, can also be treated. Treatment
dosages are typically titrated to optimize safety and efficacy.
Dosages of antibodies, peptides, and small molecules range from about 0.0001
to about 100 mg/kg, and more usually about 0.01 to about 20 mg/kg, of the
host body weight. For example, dosages can be about 1 mg/kg body weight or
about 20 mg/kg body weight or within the range of about 1 to about 10 mg/kg.
An exemplary treatment regime entails administration once per every two
weeks or once a month or once every 3 to 6 months. In some methods, two,
three, four or more monoclonal antibodies with different binding
specificities are administered simultaneously, in which case the dosage of
each antibody administered falls within the ranges indicated. For example,
in some methods antibodies to two or all three of .beta.1 integrin, .alpha.2
integrin, and .alpha.v integrin subunits are administered simultaneously. In
some methods, antibodies to the .alpha.6 integrin subunit are also
administered. Antibody is usually administered on multiple occasions.
Intervals between single dosages can be weekly, monthly or yearly. Intervals
can also be irregular as indicated by measuring blood levels of antibody to
integrins in the patient. In some methods, dosage of antibody is adjusted to
achieve a plasma antibody concentration of about 1 to about 1000 .mu.g/ml,
and in some methods about 25 to about 300 .mu.g/ml. Alternatively, antibody
can be administered as a sustained release formulation, in which case less
frequent administration is required. Dosage and frequency vary depending on
the half-life of the antibody in the patient. In general, human antibodies
show the longest half life, followed by humanized antibodies, chimeric
antibodies, and nonhuman antibodies. The dosage and frequency of
administration can vary depending on whether the treatment is prophylactic
or therapeutic. In prophylactic applications, a relatively low dosage is
administered at relatively infrequent intervals over a long period of time.
Some patients continue to receive treatment for the rest of their lives. In
therapeutic applications, a relatively high dosage at relatively short
intervals is sometimes required until the progression of the disease is
reduced or terminated, and preferably until the patient shows partial or
complete amelioration of the symptoms of the disease. Thereafter, the
patient can be administered a prophylactic regime.
Doses for nucleic acid encoding agents range from about 10 ng to 1 g, about
100 ng to about 100 mg, about 1 .mu.g to about 10 mg, or about 30 to about
300 .mu.g DNA per patient. Doses for infectious viral vectors may vary from
about 10 to about 100, or about 10.sup.3, about 10.sup.4, about 10.sup.5,
about 10.sup.6, about 10.sup.7, about 10.sup.8, about 10.sup.9, about
10.sup.10, or more virions per dose.
Agents of the invention can be administered by parenteral, topical,
intravenous, oral, subcutaneous, intrathecal, intraarterial, intracranial,
intraperitoneal, intranasal, or intramuscular means for prophylactic and/or
therapeutic treatment. In some methods, agents are injected directly into a
particular tissue where deposits have accumulated, for example, intracranial
injection. In some methods, intramuscular injection or intravenous infusion
are employed for the administration of antibody. In some methods, particular
therapeutic antibodies are injected directly into the cranium. In some
methods, antibodies are administered as a sustained release composition or
device, such as a Medipad.TM. device.
Agents of the invention can optionally be administered in combination with
other agents that are at least partly effective in the treatment of
amyloidogenic disease. In the case of Alzheimer's disease 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.
Agents of the invention are often administered as compositions comprising an
active therapeutic agent and a variety of other pharmaceutically acceptable
components. See Remington's Pharmaceutical Science (15th ed., Mack
Publishing Company, Easton, Pa., 1980). The particular formulation employed
depends on the intended mode of administration and the therapeutic
application. The compositions can also include, depending on the formulation
desired, pharmaceutically-acceptable, non-toxic carriers or diluents, which
are defined as vehicles commonly used to formulate pharmaceutical
compositions for animal or human administration. The diluent is selected so
as not to negatively impact the biological activity of the combination.
Examples of such diluents include, but are not limited to, distilled water,
physiological phosphate-buffered saline, Ringer's solution, 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.
Pharmaceutical compositions can also include large, slowly metabolized
macromolecules such as proteins, polysaccharides such as chitosan,
polylactic acids, polyglycolic acids, copolymers (such as latex
functionalized Sepharose.TM. beads, agarose, cellulose, and the like),
polymeric amino acids, amino acid copolymers, and lipid aggregates (such as
oil droplets or liposomes).
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 that can be
a sterile liquid such as water, oils, saline, glycerol, or ethanol.
Parenteral compositions for human administration are sterile, substantially
isotonic, and made under GMP conditions. 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 carriers, particularly for injectable solutions. Antibodies
can be administered in the form of a depot injection or implant preparation
that can be formulated in such a manner as to permit a sustained release of
the active ingredient. An exemplary composition comprises monoclonal
antibody at 5 mg/mL, formulated in aqueous buffer containing 50 mM L-histidine
(optional), 150 mM NaCl, adjusted to a suitable pH with HCl.
Typically, compositions are prepared as injectables, either as liquid
solutions or suspensions; solid forms suitable for solution in, or
suspension in, liquid vehicles prior to injection can also be prepared. The
preparation also can be emulsified or encapsulated in liposomes or
microparticles such as polylactide, polyglycolide, or copolymer for enhanced
adjuvant effect, as discussed above (see Langer, Science, 249:1527-33 (1990)
and Hanes et al., Advanced Drug Delivery Reviews, 28:97-119 (1997). The
agents of this invention can be administered in the form of a depot
injection or implant preparation that 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 about 0.5% to
about 10%, or about 1% to about 2%. Oral formulations include, but are not
limited to, excipients such as pharmaceutical grades of mannitol, lactose,
starch, magnesium stearate, sodium saccharine, cellulose, and magnesium
carbonate. These compositions typically take the form of solutions,
suspensions, tablets, pills, capsules, sustained release formulations or
powders and contain about 10% to about 95% of active ingredient, or about
25% to about 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)).
Coadministration 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
patch or using transferosomes (Paul et al., Eur. J. Immunol., 25:3521-24
(1995); Cevc et al., Biochem. Biophys. Acta, 1368:201-15 (1998)).
Claim 1 of 23 Claims
1. A method of inhibiting amyloid
toxicity in a human patient, comprising administering to the human patient
an effective dosage of one or more agents under conditions such that the
one or more agents inhibits amyloid toxicity; wherein the one or more
agents are selected from an antibody and a molecule that comprises an
antibody fragment; wherein the antibody or the antibody fragment binds to
an .alpha.v subunit when it is a component of an .alpha.v.beta.1 integrin;
and wherein the human patient is suffering from an amyloidogenic disease. ____________________________________________
If you want to learn more
about this patent, please go directly to the U.S.
Patent and Trademark Office Web site to access the full
patent.
|