WO2009063459A2 - Synthetic peptide copolymers for treatment of neurodevelopmental disorders - Google Patents

Abstract

Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1-related polypeptide, or a pharmaceutically acceptable salt thereof, are useful for treatment of neurodevelopmental disorders, particularly Rett syndrome.

Description

SYNTHETIC PEPTIDE COPOLYMERS FOR TREATMENT OF NEURODEVELOPMENTAL DISORDERS

FIELD OF THE INVENTION The present invention relates to compositions and methods for treatment of neurodevelopmental disorders such as Rett syndrome and, in particular, to Copolymer 1 and related peptides and polypeptides for use in such compositions and methods.

BACKGROUND OF THE INVENTION Neurodevelopmental disorders are a group of difficulties wherein there are gaps, delays or variations in the way a child's brain develops without pathological and neuroimaging evidence for brain destruction or degeneration. It can be caused by genetic, environmental, or unspecified reasons, many of which are not yet known. However, it is known that these dysfunctions often interfere with learning, behavior and adaptability across environments. The disorders are further defined as including Rett syndrome, autism and autism spectrum disorders, various syndromes which result in mental retardation such as Down's syndrome and Fragile X syndrome, and/or other types of mental deficiencies

Rett syndrome (RTT) is an X-linked dominant postnatal neurodevelopmental disorder that affects 1 in 10000 females and rarely occurs in males. Predominant features include deceleration of head growth at 2-4 months of age, followed by developmental regression mainly in speech and hand usage, hand stereotypes, seizures, autonomic dysfunction and abnormal muscle tone. RTT is the second most common cause for genetic mental retardation in females. 99% of RTT cases are sporadic, i.e., without any familial history.

The RTT disorder is almost impossible to identify at birth and its evolution usually follows four stages; however, the transition from stage to stage is not always clearly defined (Hagberg, 1992). In the first years after Rett syndrome was described by Andreas Rett (1966) followed by Hagberg (1983), it was thought to be a neurodegenerative disease. This classification was based mainly on the clinical course of the disease (nothing was known then about the gene responsible and there was very poor knowledge on neuroimaging and pathophysiology). The fact that the girls were apparently normal at birth with normal head circumference and then, after a relatively normal first year, went through a regressive course with loss of communication and motor skills, deceleration of head growth, relatively late development of epilepsy and aggravation with time of motor disability and dysfunction and occasionally early death (caused by complications of epilepsy, autonomic dysfunction or complications of motor disability) led to the assumption that the pathological process is neurodegeneration.

But with time the pathophysiology became clearer:

1. MRI of brain is normal through all these years of clinical regression with no evidence of volume loss, white matter changes, or tissue destruction (Reiss et al.,

1993). Only very late in the disease (second to third decade) there is mild cortical atrophy that can be related to secondary changes like severe epilepsy and mp abnormal ongoing secretion of neurotransmitters and neurotrophic factors.

2. Pathologically the main features are decreased neuronal cell volume and increased "packing", which is more prominent in specific brain areas, but no decrease in number of neurons (Kaufmann et al, 2000). The increased "packing" of neurons is related to a less developed dendritic tree with decreased arborization (Armstrong et al., 1995). There is no evidence for increased cell death (Armstrong et al., 1995), neuronal degeneration, atrophy inflammation or gliosis (Jellinger et al.. 1988). On the contrary (in the mouse model) newly generated hyppocampal neurons exhibit pronounced deficits in neuronal maturation, including altered expression of presynaptic proteins and reduced dendritic spine density ( Zaho et al., 2003)- all these findings are consistent with postnatal abnormal neurodevelopment and not a neurodegenerative process . 3. The explanation for the clinical regression despite the non existent progressive pathological changes is related to the fact that the expression of MECP2 (the gene responsible for the disease) is age-related. Its degree of expression in different brain areas increases with age (post-natally), making its role as transcription repressor and activator of other genes in different areas gradually more prominent through development and brain maturation.(Shahbazian et al, 2002a) The evolution of symptoms is thought to be related to the ongoing different brain systems level of expression of the gene and actually to these areas post natal dysmaturation and not degeneration (Smrt et al., 2007). 4. A relatively recent but strong evidence in favor of dysmaturation and definitely no degeneration at the basis of Rett syndrome is the promising findings by Prof A. Bird (Guy et al, 2007) (reproduced by other laboratories) of reversibility of most clinical symptoms in already symptomatic Rett null mice model (bird mice) by post-natal genetic manipulation causing re-expression of the normal gene .Their results show that neurons can develop in the complete absence of Mecp2 and acquire defects in structure and function , yet can recover almost completely if the protein is restored at a late stage . This suggests that there is no lasting defect due to development in the absence of MeCP2 that cannot be repaired simply by putting the protein back. Reversibility of clinical symptoms in the "sick" animal and not just arrest in their progression can occur only if there is no neurodegeneration but only a dysmaturation as the underlying process and as better defined "progressive neurodevelopmental disorder"

RTT is primarily caused by mutations in the X-linked methyl CpG-binding protein 2 (MECP2, also referred to as MeCP2) gene (Amir et al., 1999). While over 200 pathogenic mutations have been identified, there are eight OT transition mutations (T158M, R168X, R255X, R270X, R306C, R294X, R133C and R106W) accounting for 69% of mutation positive cases (Robertson et al., 2006).

MECP2 protein may act as either a transcriptional repressor or activator depending on the target gene with which it associates (Fuks et al., 2003; Chahrour et al., 2008). The severity of the RTT phenotype varies considerably depending on the MECP2 mutation type and location (Huppke et al., 2002; Colvin et al., 2004; Schanen et al., 2004; Bebbibgton et al., 2008; Neul et al., 2008). The degree of X chromosome inactivation skewing has also been shown to affect phenotypic variability in Mecp2-nu\l mice (Young and Zoghbi, 2004), and in RTT females (Archer et al., 2006). However, these two mechanisms only partially explain this variability.

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor that plays a major role in neuronal survival, neurogenesis and neuronal plasticity (Chahrour and Zoghbi, 2007; Egan et al., 2003; Lo, 1995; Thoenen, 2000). It has been identified as a MeCP2 target through a candidate gene approach (Martinowich et al., 2003; Chen et al., 2003), and abnormalities in BDNF homeostasis contribute to the neurological phenotype in Mecp2-nu\\ mice (Chahrour et al., 2008; Chang et al., 2006). Despite the putative role of MECP2 as a transcriptional repressor, it was found that MECP2-null mice, which develop a RTT-like phenotype, exhibit progressive deficits in BDNF expression starting at the symptomatic stage (Chang et al., 2006) Conditional deletion of BDNF in post mitotic neurons of mice mimics some of the phenotypes observed in MECP2-null mice including hind limb clasping, reduced brain weight, and reduced neuronal size in several brain sites. While specific deletion of BDNF in MECP2-null mice resulted in earlier onset of locomotor dysfunction and reduced life span, its over-expression in the same regions improved both characteristics (Chang et al., 2006).

Ampakines, a new class of compounds, are small molecules that trigger short-term increases in the duration of AMPA-mediated inward currents, and enhance alertness. They are currently being investigated as potential treatment for a range of conditions involving mental disability such as Alzheimer's disease, Parkinson's disease, schizophrenia or neurological disorders as Attention Deficit Hyperactivity Disorder (ADHD). Ogier et al.( 2007) showed that injecting ampakines (CX546) to Mecp2-mύ\ mice caused both increase in BDNF mRNA and protein levels (elevation of BDNF protein by 42%) and positive effect on breathing irregularities of the null mice, indicating that BDNF expression is plastic in MECP2-null mice.

A relatively common single nucleotide polymorphism in the BDNF gene is a substitution of valine (VaI) with methionine (Met) at codon 6 (p.V66M). This substitution is believed to disrupt folding, dimerization and intracellular trafficking of the protein (Egan et al., 2003; Chen et al, 2004), decreased grey matter volume (Huang et al., 2004), and decreased dendritic arborization with neuronal loss (Xu et al, 2000).

In the US population, the frequency of the valine/valine, valine/methionine and methionine/methionine genotypes is 70, 25 and 5%, respectively (Egan et al., 2003). Various studies have shown a relationship between the polymorphism type and the severity of clinical and imaging features in healthy subjects and in different neuropsychiatric and neurological disorders (Egan et al, 2003; Chao et al, 2007; Ho et al, 2007; Mclntosh et al, 2007; Muller et al, 2006; Borroni et al, 2008; Enoch et al, 2007; Hemmings et al, 2007; Mai et al, 2006).

Furthermore, although certain aspects of the related mechanisms which produce the RTT phenotype have been elucidated, treatment for RTT syndrome has been limited to only symptomatic treatment, such as for example treating seizures, spasticity, constipation and sleep disorders. Clearly a treatment which could improve neuronal functioning would be highly beneficial, yet to date no such treatment has been proposed, let alone proven to be effective.

Copolymer 1, also called Cop 1, is a random non-pathogenic synthetic copolymer, a heterogeneous mix of polypeptides containing the four amino acids L- glutamic acid (E), L-alanine (A), L-tyrosine (Y) and L-lysine (K) in an approximate ratio of 1.5:4.8: 1:3.6, but with no uniform sequence. Although its mode of action remains controversial, Copolymer 1 clearly helps retard the progression of human multiple sclerosis (MS) and of the related autoimmune condition studied in mice, experimental autoimmune encephalomyelitis (EAE). One form of Copolymer 1, known as glatiramer acetate, has been approved in several countries for the treatment of multiple sclerosis under the trademark Copaxone® (Teva Pharmaceutical Industries Ltd., Petach Tikva, Israel).

Recently it was found that in animal models Copolymer 1 provides a beneficial effect for several additional disorders. Thus, Copolymer 1 suppresses the immune rejection manifested in graft- versus-host disease (GVHD) in case of bone marrow transplantation (US 5,858,964), as well as in graft rejection in case of solid organ transplantation (WO 00/27417). Copolymer 1 and related copolymers and peptides have also been disclosed for treatment of autoimmune diseases (WO 00/05250), inflammatory bowel diseases (WO 2004/064717), prion-related diseases (WO 01/97785), for induction and/or enhancement of endogenous neurogenesis and/or oligodendrogenesis and for stem cell therapy in injuries, diseases, disorders or conditions, in particular those associated with the central nervous system (CNS) and peripheral nervous system (PNS) (WO 2006/057003). WO 01/52878, WO 01/93893 and US 6,844,314 disclose that Copolymer 1, Copolymer 1 -related peptides and polypeptides and T cells activated therewith protect can be used to protect CNS cells from glutamate toxicity and prevent or inhibit neuronal degeneration or promote nerve regeneration in the CNS or PNS after injury or disease. The neuroprotective effect of Copolymer 1 vaccination was demonstrated in animal models of acute and chronic neurological disorders such as spinal cord injury, optic nerve injury, head trauma, glaucoma (US 7,407,936), amyotrophic lateral sclerosis (US 7,351,686), neurodegenerative diseases such as Huntington's disease, Alzheimer's disease or Parkinson's disease (WO 2005/046719), and psychiatric disorders (WO 2005/056574).

Copolymer 1 exerts a marked suppressive effect on EAE induced by various encephalitogens, in several species. It is a very well tolerated agent with only minor adverse reactions and high safety profile. Treatment with Cop 1 by ingestion or inhalation is disclosed in US 6,214,791.

The immunomodulatory effect of glatiramer acetate (GA) was attributed to its ability to induce Th2/3 cells that secrete high levels of anti-inflammatory cytokines. These cells cross the blood brain barrier (BBB), accumulate in the CNS, and express in situ IL-IO, TGF-β and BDNF. Furthermore, the GA-specific cells induce bystander effect on neighboring CNS cells to express these beneficial factors and reduce IFN- γ expression. A key issue in the capability of GA to counteract the pathological process is its effect on the neuronal system, which is the actual target of the pathological process.

The background art does not teach or suggest a treatment for neurodevelopmental disorders in general, and for RTT syndrome in particular, other than symptomatic treatments. The background art also does not teach or suggest a treatment for RTT syndrome for improving neuronal function. None of the above- mentioned references discloses or suggests use of glatiramer acetate (GA) for treatment of Rett syndrome or any other neurodevelopmental disorder.

SUMMARY OF THE INVENTION

The present invention overcomes at least some of the deficiencies of the background art.

In one aspect, the present invention provides an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for use in the treatment ^"of a neurodevelopmental disorder. In another aspect, the present invention is directed to the use of an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related- peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for the treatment of a neurodevelopmental disorder. In a further aspect, the invention provides a pharmaceutical composition for treatment of a neurodevelopmental disorder, comprising an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 related polypeptide, or a pharmaceutically acceptable salt thereof, and a pharmaceutically active carrier or excipient. In an additional aspect, the invention provides a method for treatment of a neurodevelopmental disorder, comprising administering to an individual in need a therapeutically active amount of an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 related polypeptide, or a pharmaceutically acceptable salt thereof.

The neurodevelopmental disorders that can be treated according to the invention include Rett (RTT) syndrome and also autism and autism spectrum disorders, various syndromes which result in mental retardation such as Down's syndrome and Fragile X syndrome, and/or other types of mental deficiencies. In one preferred embodiment, the disorder is RTT syndrome.

The active agent for use in the invention is preferably Copolymer 1 of average molecular weight from 2,00 to 40,000 Da, most preferably in the form of its acetate salt known under the generic name glatiramer acetate, having an average molecular weight between 4,700 and 11,000 Da.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a graph showing severity of RTT symptoms according to age group.

Fig. 2 is a graph showing change in Percy Score for the BDNF polymorphism compared with wild-type (Val/Val) BDNF. Fig. 3 depicts a Kaplan-Meier curve for age at onset of seizures for cases with p.R168X (with censor points marked as small grey lines)

Figs. 4A-4B are photographs showing BDNF immunohistochemical staining.

BDNF expressing cells (yellow) in representative brain sections of Mecp2 mice after 14 subcutaneous daily injections with GA. 4 A. sham treatment with PBS; 4B. GA treatment (2 mg/mouse). GA treatment resulted in significant elevation of

BDNF expressing cells in the cortex (x4 magnification).

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method for treating a neurodevelopmental disorder, comprising administering to a subject in need a therapeutically effective amount of an active agent selected from the group consisting of Copolymer I₅ a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof

In another aspect, the present invention provides an active agent selected from Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for use in the treatment of a neurodevelopmental disorder.

In a further aspect, the present invention provides the use of an active agent selected from Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1- related polypeptide, or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for the treatment of a neurodevelopmental disorder.

In still another aspect, the present invention provides a pharmaceutical composition comprising an active agent selected from Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for treatment of a neurodevelopmental disorder.

As used herein, the terms "Copolymer 1" and "Glatiramer acetate" may be used interchangeably. For the purpose of the present invention, " Copolymer 1 or a Copolymer 1 -related peptide or polypeptide" is intended to include any peptide or polypeptide, including a random heterocopolymer, that cross-reacts functionally with myelin basic protein (MBP) and is able to compete with MBP on the MHC class II in the antigen presentation.

The active agent of the invention may comprise a random copolymer comprising a suitable quantity of a positively charged amino acid such as lysine or arginine, in combination with a negatively charged amino acid (preferably in a lesser quantity) such as glutamic acid or aspartic acid, optionally in combination with a non-charged neutral amino acid such as alanine, glycine, or valine serving as a filler, and optionally with an amino acid adapted to confer on the copolymer immunogenic properties, such as an aromatic amino acid like tyrosine, phenylalanine or tryptophan. Such compositions may include any of those copolymers disclosed in WO 00/05250, the entire contents of which being herewith incorporated herein by reference.

More specifically, the active agent for use in the present invention comprises at least one copolymer selected from the group consisting of random copolymers comprising one amino acid selected from each of at least three of the following groups: (a) lysine and arginine; (b) glutamic acid and aspartic acid; (c) alanine, glycine and valine; and (d) tyrosine, phenylalanine and tryptophan.

The copolymers for use in the present invention can be composed of L- or D- amino acids or mixtures thereof. As is known by those of skill in the art, L-amino acids occur in most natural proteins. However, D-amino acids are commercially available and can be substituted for some or all of the amino acids used to make the terpolymers and other copolymers used in the present invention. The present invention contemplates the use of copolymers containing both D- and L-amino acids (DL), as well as copolymers consisting essentially of either L- or D-amino acids. All D-copolymer 1 and DL-copolymer 1 were disclosed in US 5,858,964 and shown to be useful as the all L-copolymer 1 in prevention and treatment of GVHD in cases of organ transplantation that develop GVHD, particularly bone marrow transplantation.

In one more preferred embodiment of the invention, the copolymer contains four different amino acids, each from a different one of the groups (a) to (d). A preferred copolymer according to this embodiment comprises in combination alanine, glutamic acid, lysine, and tyrosine, of net overall positive electrical charge and of a molecular weight of about 2 - 40 kDa, preferably of about 2 -13 IdDa, and is more preferably Copolymer 1 of average molecular weight of about 4,7 - 13 kDa, more preferably about 5 - 9 IdDa or, alternatively, more preferably of about 13 - 18 IdDa.. Preferred molecular weight ranges and processes for making a preferred form of Cop 1 are described in U.S. Patent No. 5,800,808, the entire contents of which being hereby incorporated in the entirety.

According to a further embodiment, the copolymer comprises alanine, glutamic acid, lysine, and tyrosine in the molar ratios of: glutamic acid about 0.14, alanine about 0.43, tyrosine about 0.10 and lysine about 0.33. According to a preferred embodiment, the molar ratios of the amino acid residues include the following relative molar ratios: 0.17 glutamic acid to 0.38 lysine to 0.49 alanine to 0.1 tyrosine. According to another preferred embodiment, said relative molar ratios are 0.19 glutamic acid to 0.4 lysine to 0.6 alanine to 0.1 tyrosine.

The definition of "Copolymer 1 related-polypeptide" according to the invention is meant to encompass other synthetic amino acid copolymers containing the amino acids phenylalanine, glutamic acid, alanine and lysine (poly FEAK), or tyrosine, phenylalanine, alanine and lysine (poly YFAK), and any other similar copolymer to be discovered that can be considered a universal antigen similar to Copolymer 1.

It is clear that this is given by way of example only, and that the active agent can be varied both with respect to the constituents and relative proportions of the constituents if the above general criteria are adhered to. Thus, the copolymer may be a polypeptide from about 15 to about 100, preferably from about 40 to about 80, amino acids in length, and is preferably the copolymer having the generic name glatiramer acetate.

In another embodiment, the copolymer contains three different amino acids each from a different one of three groups of the groups (a) to (d). These copolymers are herein referred to as terpolymers.

In one embodiment, the terpolymers for use in the present invention contain tyrosine, alanine, and lysine, hereinafter designated YAK. The average molar fraction of the amino acids in these terpolymers can vary. For example, tyrosine can be present in a mole fraction of about 0.005-0.250; alanine can be present in a mole fraction of about 0.3 - 0.6; and lysine can be present in a mole fraction of about 0.1-0.5. The average molecular weight is between 2,000 - 40,000 Da, and preferably between about 3,000 - 35,000 Da. In a more preferred embodiment, the average molecular weight is about 5,000 - 25,000 Da. It is possible to substitute arginine for lysine, glycine for alanine, and/or tryptophan for tyrosine. In another embodiment, the terpolymers for use in the present invention contain tyrosine, glutamic acid, and lysine, hereinafter designated YEK. The average molar fraction of the amino acids in these terpolymers can vary: glutamic acid can be present in a mole fraction of about 0.005 - 0.300, tyrosine can be present in a mole fraction of about 0.005 - 0.250, and lysine can be present in a mole fraction of about 0.3 - 0.7. The average molecular weight is between 2,000 - 40,000 Da, and preferably between about 3,000 - 35,000 Da. In a more preferred embodiment, the average molecular weight is about 5,000 - 25,000 Da. It is possible to substitute aspartic acid for glutamic acid, arginine for lysine, and/or tryptophan for tyrosine.

In another embodiment the terpolymers for use in the present invention contain lysine, glutamic acid, and alanine, hereinafter designated KEA. The average molar fraction of the amino acids in these polypeptides can also vary. For example, glutamic acid can be present in a mole fraction of about 0.005 - 0.300, alanine can be present in a mole fraction of about 0.005 - 0.600, lysine can be present in a mole fraction of about 0.2 - 0.7. The average molecular weight is between 2,000 - 40,000 Da, and preferably between about 3,000 - 35,000 Da. In a more preferred embodiment, the average molecular weight is about 5,000 - 25,000 Da. It is possible to substitute aspartic acid for glutamic acid, glycine for alanine, and/or arginine for lysine.

In another embodiment, the terpolymers for use in the present invention contain tyrosine, glutamic acid, and alanine, hereinafter designated YEA. The average molar fraction of the amino acids in these polypeptides can vary. For example, tyrosine can be present in a mole fraction of about 0.005 - 0.250, glutamic acid can be present in a mole fraction of about 0.005 - 0.300, and alanine can be present in a mole fraction of about 0.005 - 0.800. The average molecular weight is between 2,000 - 40,000 Da, and preferably between about 3,000 - 35,000 Da. In a more preferred embodiment, the average molecular weight is about 5,000 - 25,000 Da. It is possible to substitute tryptophan for tyrosine, aspartic acid for glutamic acid, and/or glycine for alanine. In a more preferred embodiment, the mole fraction of amino acids of the terpolymers is about what is preferred for Copolymer 1. The mole fraction of amino acids in Copolymer 1 is glutamic acid about 0.14, alanine about 0.43, tyrosine about 0.10, and lysine about 0.34. The most preferred average molecular weight for Copolymer 1 is between about 5,000 - 9,000 Da. The activity of Copolymer 1 for the composition disclosed herein is expected to remain if one or more of the following substitutions is made: aspartic acid for glutamic acid, glycine for alanine, arginine for lysine, and tryptophan for tyrosine.

The molar ratios of the monomers of the more preferred terpolymer of glutamic acid, alanine, and tyrosine, or YEA, is about 0.21 to about 0.65 to about 0.14. The molar ratios of the monomers of the more preferred terpolymer of glutamic acid, alanine and lysine, or KEA, is about 0.15 to about 0.48 to about 0.36. The molar ratios of the monomers of the more preferred terpolymer of glutamic acid, tyrosine, and lysine, or YEK, is about 0.26 to about 0.16 to about 0.58. The molar ratios of the monomers of the more preferred terpolymer of tyrosine, alanine and lysine, or YAK, is about 0.10 to about 0.54 to about 0.35.

The terpolymers used in the invention can be made by any procedure available to one of skill in the art. For example, the terpolymers can be made under condensation conditions using the desired molar ratio of amino acids in solution, or by solid phase synthetic procedures. Condensation conditions include the proper temperature, pH, and solvent conditions for condensing the carboxyl group of one amino acid with the amino group of another amino acid to form a peptide bond. Condensing agents, for example dicyclohexyl-carbodiimide, can be used to facilitate the formation of the peptide bond. Blocking groups can be used to protect functional groups, such as the side chain moieties and some of the amino or carboxyl groups against undesired side reactions.

For example, the process disclosed in U.S. Patent 3,849,650, can be used wherein the N-carboxyanhydrides of tyrosine, alanine, γ-benzyl glutamate and N ε- trifluoroacetyl-lysine are polymerized at ambient temperatures in anhydrous dioxane with diethylamine as an initiator. The γ-carboxyl group of the glutamic acid can be deblocked by hydrogen bromide in glacial acetic acid. The trifluoroacetyl groups are removed from lysine by 1 molar piperidine. One of skill in the art readily understands that the process can be adjusted to make peptides and polypeptides containing the desired amino acids, that is, three of the four amino acids in Copolymer 1, by selectively eliminating the reactions that relate to any one of glutamic acid, alanine, tyrosine, or lysine. For purposes of this application, the terms "ambient temperature" and "room temperature" mean a temperature ranging from about 20 to about 26°C.

The molecular weight of the terpolymers can be adjusted during polypeptide synthesis or after the terpolymers have been made. To adjust the molecular weight during polypeptide synthesis, the synthetic conditions or the amounts of amino acids are adjusted so that synthesis stops when the polypeptide reaches the approximate length which is desired. After synthesis, polypeptides with the desired molecular weight can be obtained by any available size selection procedure, such as chromatography of the polypeptides on a molecular weight sizing column or gel, and collection of the molecular weight ranges desired. The present polypeptides can also be partially hydrolyzed to remove high molecular weight species, for example, by acid or enzymatic hydrolysis, and then purified to remove the acid or enzymes. In one embodiment, the terpolymers with a desired molecular weight may be prepared by a process which includes reacting a protected polypeptide with hydrobromic acid to form a trifluoroacetyl-polypeptide having the desired molecular weight profile. The reaction is performed for a time and at a temperature which is predetermined by one or more test reactions. During the test reaction, the time and temperature are varied and the molecular weight range of a given batch of test polypeptides is determined. The test conditions which provide the optimal molecular weight range for that batch of polypeptides are used for the batch. Thus, a trifluoroacetyl-polypeptide having the desired molecular weight profile can be produced by a process which includes reacting the protected polypeptide with hydrobromic acid for a time and at a temperature predetermined by test reaction. The trifluoroacetyl-polypeptide with the desired molecular weight profile is then further treated with an aqueous piperidine solution to form a low toxicity polypeptide having the desired molecular weight.

In a preferred embodiment, a test sample of protected polypeptide from a given batch is reacted with hydrobromic acid for about 10-50 hours at a temperature of about 20-28⁰C. The best conditions for that batch are determined by running several test reactions. For example, in one embodiment, the protected polypeptide is reacted with hydrobromic acid for about 17 hours at a temperature of about 26°C. In one embodiment, the Copolymer 1 related peptide is selected from the thirty-two peptides of SEQ ID NO: 1-32 below.

According to various embodiments of the present invention, the Copolymer 1 -related polypeptide or peptide may be a random polypeptide from about 15 to about 100 amino acids, for example from about 40 to about 80 amino acids in length. According to various alternative embodiments, the copolymer is an ordered synthetic peptide of from 6 to 25 amino acids, for example an ordered synthetic peptide of 10 to 20 amino acids, preferably the 15-mer peptides of SEQ ID NO: 1-32 below:

Peptide Sequence

SEQ ID NO.

1 AAAYAAAAAAKAAAA

2 AEKYAAAAAAKAAAA

3 AKEYAAAAAAKAAAA

4 AKKYAAAAAAKAAAA

5 AEAYAAAAAAKAAAA

6 KEAYAAAAAAKAAAA

7 AEEYAAAAAAKAAAA

8 AAEYAAAAAAKAAAA

9 EKAYAAAAAAKAAAA

10 AAKYEAAAAAKAAAA

11 AAKYAEAAAAKAAAA

12 EAAYAAAAAAKAAAA

13 EKKYAAAAAAKAAAA

14 EAKYAAAAAAKAAAA

15 AEKYAAAAAAAAAAA

16 AKEYAAAAAAAAAAA Peptide Sequence

SEQ ID NO.

17 AKKYEAAAAAAAAAA

18 AKKYAEAAAAAAAAA

19 AEAYKAAAAAAAAAA

20 KEAYAAAAAAAAAAA

21 AEEYKAAAAAAAAAA

22 AAEYKAAAAAAAAAA

23 EKAYAAAAAAAAAAA

24 AAKYEAAAAAAAAAA

25 AAKYAEAAAAAAAAA

26 EKKYAAAAAAAAAAA

27 EAKYAAAAAAAAAAA

28 AEYAKAAAAAAAAAA

29 AEKAYAAAAAAAAAA

30 EKYAAAAAAAAAAAA

31 AYKAEAAAAAAAAAA

32 AKYAEAAAAAAAAAA

According to the present invention, the preferred copolymer for use in the composition of the invention is Copolymer 1, most preferably in the form of its acetate salt known under the generic name glatiramer acetate (GA). As mentioned before, glatiramer acetate has been approved in several countries for the treatment of multiple sclerosis (MS) and was shown to be well tolerated with only minor side reactions which were mostly mild reactions at the injection site (Johnson et al, 1995).

Examples of neurodevelopmental disorders that can be treated with an agent according to the present invention include, but are not limited to, RTT syndrome, autism and autism spectrum disorders, and various syndromes which result in mental retardation such as Down's syndrome, Fragile X syndrome and/or other types of mental deficiencies. In one preferred embodiment, the disorder is RTT syndrome. In the method of the present invention, the term "therapeutically effective amount" refers to an amount of active agent that is effective to treat a subject afflicted with a neurodevelopmental disorder such as Rett disorder and prevent, cure, reverse, attenuate, alleviate, minimize, suppress or halt at least some of the symptoms/deleterious effects caused by or associated with the disorder.

Glatiramer acetate, when administered either subcutaneously or intraperitoneally to EAE (Experimental Autoimmune Encephalomyelitis) mice, a known animal model for MS, was found to increase and maintain higher levels of serum and brain BDNF. GA was also found to increase BDNF serum levels in multiple sclerosis patients, adding a potentially neuroprotective aspect to its positive effect in this autoimmune disease. In accordance with the present invention, Copolymer 1 was tested in Mecp2-mή\ mice, a mouse model of Rett syndrome, and shown to elevate the brain BDNF level in said mice.

GA has not been taught or suggested as a treatment for neurodevelopmental disorders. It is believed that GA may, for example, improve cognitive functions in subjects with neurodevelopmental disorders.

Down's Syndrome is a common neurodevelopmental genetic disease. Previously, a correlation has been shown between BDNF forebrain levels and working memory in an animal model of Down's syndrome (Ts65Dn mice) (Bimonte-Nelson et al., 2003). It is believed that administration of GA to such patients would improve their cognitive functions, possibly (alternatively or additionally) preventing or delaying Alzheimer- like dementia that is characteristic of these patients in early adulthood.

Fragile X syndrome is another common neurodevelopmental genetic disease, which features an expansion of CGG-repeats in the gene [fragile X mental retardation 1 (Fmrl)] that encodes fragile X mental retardation protein (FMRP). Once the number of such repeats is greater than about 200, expression of the gene is blocked, and symptoms of the disease become manifest. Recently, BDNF was found to increase long term potentiation of neurons in brain slices from a mouse animal model of Fragile X syndrome (Fmrl mice; Lauterborn et al.. 2007). It is believed that administration of GA to such patients would improve their cognitive functions. The active agent according to the invention can be administered to the patient per se or as an active ingredient as part of a pharmaceutical composition along with a pharmaceutically acceptable carrier.

As used herein, the phrases "physiologically acceptable carrier" and "pharmaceutically acceptable carrier" which may be interchangeably used refer to a carrier or a diluent that does not cause significant irritation to an organism and does not abrogate the biological activity and properties of the administered compound.

An adjuvant is included under these phrases.

Herein the term "excipient" refers to an inert substance added to a pharmaceutical composition to further facilitate administration of an active ingredient. Examples, without limitation, of excipients include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils and polyethylene glycols.

Copolymer 1 has been demonstrated to be active when injected subcutaneously, intraperitoneally, intravenously or intramuscularly. Copolymer- 1 therapy is presently limited to its daily subcutaneous administration, which slow progression of disability and reduce the relapse rate in exacerbating-remitting multiple sclerosis.

U.S. Patent No. 6,214,791 discloses methods for treating multiple sclerosis by oral administration of copolymer 1 through ingestion or inhalation. When copolymer 1 is introduced orally, it may be mixed with other food forms and consumed in solid, semisolid, suspension, or emulsion form; and it may be mixed with pharmaceutically acceptable carriers, including water, suspending agents, emulsifying agents, flavor enhancers, and the like. In one embodiment, the oral composition is enterically- coated. Copolymer 1 may also be administered nasally in certain of the above-mentioned forms by inhalation or nose drops. Furthermore, oral inhalation may be employed to deliver copolymer- 1 to the mucosal linings of the trachea and bronchial passages. Copolymer 1 can also be administered as eye drops as disclosed in WO For oral administration, the dosage of Copolymer 1 is from 0.1 to 1000 mg per day, which may be administered as a single dose or in multiple dosages. In one embodiment, the oral composition is enterically-coated.As understood by one skilled in the art, the therapeutically effective dosage is generally a function of a patient's age, sex, and physical condition, as well as a function of other concurrent treatments being administered. The determination of the optimum, therapeutically effective dosage is well within the scope of one skilled in the art.

The pharmaceutical compositions of the present invention are prepared by conventional methods known in the art. Techniques for formulation and administration of drugs may be found in "Remington's Pharmaceutical Sciences," Mack Publishing Co., Easton, PA, latest edition, which is incorporated herein by reference. Preferably, the composition is lyophilized and formed into an aqueous solution suitable for subcutaneous, intramuscular or intravenous injection.. According to various embodiments of the present invention, the therapeutically effective amount of the copolymer ranges from about 1.0 mg to about 500.0 mg/day, preferably from 10 or 20 to 100 mg/day of L-glatiramer acetate. Alternatively, such therapeutically effective amounts of the at least one copolymer are from about 20.0 mg to about 100.0 mg/day. The all D- and DL- copolymers may be used in lower doses. The composition of the invention may comprise copolymer 1 molecules of different molecular weights, for example, a mixture of polypeptides having an average molecular weight of about 2 to 20 kDa, preferably about 4 to about 8.6 KDa or about 6.25 to about 8.4 KDa or 7.7 IdDa, as disclosed in US 6,939,539..

Pharmaceutical compositions for use in accordance with the present invention may be formulated in conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries, which facilitate processing of the active ingredients into preparations which, can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. For injection, the active ingredients of the invention may be formulated in aqueous solutions, preferably in physiologically compatible buffers such as Hank's solution, Ringer's solution, or physiological salt buffer. For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

For oral administration, the compounds can be formulated readily by combining the active compounds with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions, and the like, for oral ingestion by a patient. Pharmacological preparations for oral use can be made using a solid excipient, optionally grinding the resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl- cellulose, sodium carbomethylcellulose; and/or physiologically acceptable polymers such as polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate.

For administration by nasal inhalation, the active ingredients for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation from a pressurized pack or a nebulizer with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichloro- tetrafluoroethane or carbon dioxide. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, e.g., gelatin for use in a dispenser may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

The use of GA may also be modified from dosages which are known in the art, including changing the amount and/or frequency of administration according to the particular neurodevelopmental disorder being treated (and also optionally according to the stage of such a disorder). The method of administration, in addition to those described above, may also optionally include T-cell vaccination and the like. Treatment of the above-described diseases according to the present invention may be combined with other treatment methods known in the art drugs which are symptom-related, for example, with anticonvulsant drugs, anti-gastroesophageal reflux drugs, muscle relaxants, anxiolytics, and the like..

Reference is now made to the following examples which, together with the above description, illustrate the invention in a non limiting fashion.

EXAMPLES

Example 1: Relationship between BDNF polymorphism and disease severity in Rett Syndrome

1.1 Materials and methods

Data for this study, based on RTT subjects with a confirmed MECP 2 mutation, were ascertained from two sources: 1) cases in the Australian Rett Syndrome Database (ARSD) on whom DNA samples had been stored in the Westmead laboratory and are available for analyses of BDNF polymorphisms; and 2) cases observed at the Sheba Medical Center, Israel. The cases from the ARSD (n=131) represent 42.8% of all cases known to the ARSD at December 2006.

The ARSD is a population-based database of RTT subjects born since 1976 (Colvin et al., 2003) so that ages ranged from 2.9 to 28.9 years at 2004 follow-up. Israeli cases were identified from those cases seen at Sheba Medical Center, with ages ranging from 3.5 to 42 years.

Clinical severity was assessed using what we have coined the "Percy" scale

(Colvin et al., 2003; Schanen et al., 2004), which takes into account early developmental characteristics as well as current clinical features and has been shown to be an appropriate measure. Severity scales provide quantitative estimates of clinical severity. Each scale is a summation of individual items related to RTT characteristics which are graded on a discrete scale based on their specific severity or degree of abnormality, with the highest level corresponding to the most severe or abnormal presentation. The Percy scale, that has 15 items with maximum possible score of 45, was chosen for this study because of its reasonable balance between current functioning and developmental characteristics (Colvin et al, 2003). Data used to determine the scores were derived from information for ARSD cases that were provided to the ARSD in the 2004 follow-up questionnaire and coded for previous analyses (Young et al., 2007). Information for Israeli cases was extracted from case records and coded in the same way as the Australian cases. Age at onset of seizures (if present, or age at data collection if seizures were not present) was recorded for cases in both cohorts.

The BDNF polymorphism (p.V66M) was genotyped using TaqMan® SNP Genotyping Assays (assay ID c_11592758_10, Applied Biosystems) according to manufacturer's protocol.

Statistical analysis was performed on the combined cohort and relevant subsets using Stata version 9. Comparison of groups was done using ANOVA or the Kruskal-Wallis test where normality assumptions did not hold. Regression models were linear with dummy variables for categorical factors (including BDNF polymorphism and cohort). The effect of BDNF polymorphism on "clinical severity using the Percy score" was assessed for all cases with and without adjusting for age as a continuous variable. Age at onset of seizures was analyzed using Cox regression with censoring at time of seizure onset or age at data collection (if not epileptic) and results are presented as hazard ratios (HR) and 'survival' curves were plotted using Kaplan-Meier estimates. The Mann- Whitney test was used to compare median times of seizure onset for the BDNF polymorphisms. Analyses were repeated separately for each of the two MECP2 mutation groups, ρ.T158M and P.R168X. 1.2 Results There were a total of 182 cases in the study with 72.0% (131) from ARSD and 28.0% (51) from Israel. The mean age at data collection for the Australian cases (15.9) was higher than for the Israeli cases (13.8) (p=^:0.02). Eight common mutations were found in 30/46 Israeli cases and 97/131 Australian cases, with the commonest mutations being ρ.T158M (15.8%) and p.R168X (11.9%) (Table 1). Severity scores were available for 118/131 ARSD cases and 45/51 Israeli cases. The mean severity scores for Australian cases (25.3) and Israeli cases (27.2) were similar (p=0.11). The overall mean Percy score was 25.8 and ranged from 8 to 43. There was a slight increase in severity by age group from 24.6 to 26.3, although severity was greatest in those aged 16-21 years (Fig. 1). Of the 178 cases with known seizure status, 136 (76.4%) had commenced seizures. The median age at onset for the entire cohort was 5 years (95% CI 4.5 - 6 years). Seizures were present in 82.8% of Australian cases compared with only 60% of Israeli cases (p=0.04). However, in those cases with seizures, the median ages at diagnosis in Israeli (3 years) and Australian (4 years) cases were similar (p=0.63).

For BDNF, 57.2% were homozygous for the wildtype (WT; Val/Val) allele, 37.6% heterozygous (Val/Met) and 5.2% were homozygous for the mutated (Met/Met) allele, demonstrating Hardy- Weinberg equilibrium (p=0.84). Since only a small number of cases were homozygous for the Met/Met allele (4 from the Israeli cohort and 5 from the ARSD cohort), they were excluded from the severity and seizure comparisons. Overall those heterozygous for the BDNF polymorphism were slightly more severe than those who were homozygous for the wild type (increased severity 2.1, p=0.09). When severity was examined for those with the p.R168X mutation ^=19 with scores), severity was associated with a 6 point increase in the severity score among heterozygotes for the BDNF polymorphism, both unadjusted (p=0.02) and adjusted for age (p=0.03). No such difference was seen with the p.T158M mutation (n=23 with scores) (Table 2, Fig. 2). Risk of seizure onset, after accounting for cohort effects, was not significantly affected by BDNF polymorphism (HR when heterozygous for the BDNF polymorphism 1.2, p-value = 0.24, 95% CI 0.9 - 1.8). The median age at onset of seizures, in cases with seizures, was similar for heterozygous (4.2 years) and wild-type (3.5 years) cases (p=0.53). However, for cases with the p.R168X mutation, heterozygous cases had a significantly increased risk of seizure onset (HR 5.3, p-value 0.006, 95% CI 1.6 - 17.7), and had an earlier age at seizure onset (median = 2 years), than those who were homozygous for the WT BDNF allele (median = 7 years) (Fig. 3) Of the 9 cases homozygous for the mutant BDNF allele who were not included in this analysis, 6 had commenced seizures (median age at onset 5 years) and 3 had not.

Table 1 Distribution of MECP2 mutations by case source

Table 2. Severity and BDNF Polymorphism

* Change in Percy Score for heterozygotes compared with wild type (Val/Val)

# Israel=0, ARSD=I

1.3 Discussion

Overall, those who were heterozygous for the p.V66M variant were slightly more severe than those homozygous for the wildtype (Val/Val) BDNF allele.

Moreover, patients with the p.R168X mutation had a 6 point increase in the Percy severity score, as well as a 5-fold increase in risk of seizures, in individuals heterozygous for the BDNF allele after adjusting for age. Neither of these effects however were seen in patients with p.T158M mutation. The distribution of the

BDNF polymorphism variant was found to be similar to what has been previously reported in the literature in Caucasian populations (Egan et al., 2003) including a cohort of Rett syndrome patients (Nectoux et al., 2008).

Both the type of mutation and degree of skewing of X-chromosome inactivation have an effect on severity in RTT. The data on the X-inactivation skewing were not available for a significant proportion of our cohort, making it impossible to be used as a variable in this analysis. This missing information could affect our results in both directions, especially as the contribution of X-inactivation to the variability of phenotype in these specific mutations has been previously demonstrated (Archer et al., 2006). Despite this shortcoming, the fact that a relationship was found between the p.V66M polymorphism and severity is actually consistent with previous studies in normal individuals, and other neuropsychiatric and neurological diseases. This would suggest a role for BDNF activity in the pathogenesis of RTT. This role may be non-specific, as suggested in the other diseases, and may relate to the general role of BDNF in neuronal survival, and plasticity. It could also be explained by an as yet untested possibility that the two proteins (MECP2 and BDNF) have certain overlapping effects. In addition, it could be that MECP2 dysfunction reduces overall neuronal activity, thereby indirectly resulting in decreased BDNF (Dani et al., 2005), further accentuating possible adverse effects of a "less efficient" BDNF protein variant. On the other hand, it could also suggest a direct role of MECP2 protein in BDNF gene expression, and as a consequence a significant role of Bdnf/BDNF protein activity in the pathogenesis of RTT in both the mouse model and the human.

In a recent publication by Nectoux et al. (2008), the effect of the common BDNF functional polymorphism was investigated in a cohort of 81 girls with various mutations looking at both a general score using the Kerr scoring system (Kerr et al., 2001) and also on 14 different clinical features separately (combining all mutations together). Although the authors did not find a significant relationship with the overall severity score they, did find that the BDNF genotype distribution tended to be different in the areas of hand skills and age of seizure onset (defined simply as a categorical variable, with early onset described as before 2 years of age). They suggested that the polymorphism might even be protective against seizures. In contrast to their findings, and consistent with the present hypothesis regarding the relative dysfunction of the p.V66M polymorphism, the present inventors found that age of onset of seizures was earlier in those heterozygous for the BDNF polymorphism, particularly for people with the p.R168X mutation. We did not categorize age at seizure onset but instead we retained the actual ages at onset or ages at data collection in people without seizures and used survival analysis to take account of censoring. It was also found that overall severity was greater in those who were heterozygous for the p.V66M allele compared with those with the wild-type BDNF sequence, particularly in those individuals with the p.R168X MECP2 mutation. It may be that both the earlier age of seizure onset and the additional severity we find with the Val/Met variant in subjects with the p.R168X mutation are manifestations relating to the general role of BDNF expression in RTT pathogenesis. Thus, in addition to mutation type and degree of X-chromosome skewing, the common BDNF polymorphism appears to be another genetic modifier of RTT severity, indicating that BDNF function may play a significant role in the pathogenesis of RTT.

Example 2. Effect of glatiramer acetate on BDNF levels of MECP2 null mice

The genetic cause for most of Rett syndrome cases are mutations in the X- linked MECP2 gene. Mecp2 is a transcription regulator of several genes: one of the main affected genes is BDNF, with progressive decreased level of BDNF protein

(up to 69% of the wild type) in Mecp2-mutated and deficient (null) mice, which are the Rett syndrome animal model.

Mecp2-deficient (null) mice or with truncation mutation develop at 4 to 6 weeks neurological symptoms which highly resemble human Rett syndrome including motor impairment, seizures, hypoactivity, scoliosis, and repetitive stereotyped forepaw clasping. The various Mec/?2-deficient mice strains show progressive decrease in BDNF level in symptomatic mice (6-8 weeks of age) but not in pre-symptomatic mice (2 weeks), exceeding up to 69% decrease in whole brain protein extract compared to that of wild type mice (Chang et al., 2006). It was also shown that injection of the ampakine CX546 to Mecp2-mx\l mice caused elevation of BDNF protein and mRNA levels, indicating that BDNF expression are plastic in these mice. This resulted also in positive effect on breathing irregularities of the Mecp2-mx\\ mice (Ogier et al., 2007). The aim of this study was to investigate the effect of glatiramer acetate (GA) on BDNF levels of Mecp2-mxl\ mice and its effect on their brain neurogenesis. GA was administered daily by injection at both the pre-symptomatic and the symptomatic stages and the brain BDNF levels was assessed using immuno- histochemical analysis for BDNF staining, followed by advanced mathematical quantification of the positively labeled areas. In addition, the mice were inspected for various Rett manifestations to find out whether the BDNF elevation results in a positive functional therapeutic effect.

2.1 Experimental The experiment was performed in 3 transgenic mice and 2 control mice. The effect of GA treatment on BDNF expression was analyzed by immunostaining of brain sections from Mecp2-null mice (B6.129S-Mecp2^tmlHzo/J, purchased from Jackson Laboratories) which are considered one of the most appropriate animal models for Rett syndrome, versus C57BL/6 normal healthy mice with a similar genetic background to the Mecp2 strain. Male mice (16-week old) were daily injected subcutaneously with GA (2 mg/mouse; batch 24902007, obtained from Teva Pharmaceutical Industries, Israel) or sham treatment with phosphate-buffered saline (PBS). The experiment included also one Mecp2 mouse which was not treated at all. One day after the last injection mice were anesthetized and perfused transcardially. Determination of BDNF expression was performed by immuno- histochemical staining. Free-floating brain sections (16 μm thick) were pre- incubated with 20% horse serum and 0.05% saponin and incubated overnight with primary antibody: chicken anti-human BDNF (10 μg/ml; Promega, Madison, WI, catalog No. gl64A). The second step staining was performed by labeling with highly cross-absorbed donkey anti-chicken cy3-conjugated species-specific antibody at 1:200 dilution (Catalog No. 703-165-155; Jackson ImmunoResearch Laboratories, West Grove, PA), for 20-40 min. Quantitative analysis of BDNF expressing cells was performed by counting positively stained cells in areas of 0.54 μm² in the cortex (layers 2-3 and 5-6, in both the anterior and the posterior motor cortex) and in the hypothalamus midline region. Results were averaged from at least 20 sections for each brain structure for each mouse. Significance compared to sham treatment control was assayed by Student's t test, (p <0.05). * Significant effect over sham control.

2.2 Results The results are shown in Table 3 and Figs. 4A-4B. A drastic decrease in the number of BDNF expressing cells was observed in the cortex of Mecp2 mice (Fig.

4A) in comparison to C57BL/6 mice (both in layers 2-3 and 5-6). GA treatment resulted in significant elevation of BDNF expression in the cortex (Fig. 4B) reaching a level similar to that observed in the healthy C57BL/6 mice. GA treatment did not affect the normal BDNF expression in the cortex of C57BL/6 mice. In the hypothalamus no reduction in the BDNF level in the Mecp2 transgenic mice was observed. GA had no effect on the BDNF levels in C57BL/6 normal mice.

Thus, GA has an effect of repair on BDNF expression. This effect was observed only in regions manifesting BDNF deficiency in the Rett model.

Table 3. Effect of GA on the number of BDNF expressing cells in Rett model mice

^Significant effect over sham control by Student's t test (p <0.05). The results obtained in this experiment demonstrate that GA treatment of Mecp2-mx\\ mice leads to elevation of BDNP protein/mRNA expression in their brains and indicate that GA might affect the mice brain ultrastructure (neurogenesis), change in size of neurons, and dendritic arborization. Based on previous studies that showed that BDNF elevation by both genetic over-expression and by pharmacological intervention affects Mecp2-mύl mice breathing pattern, locomotor behavior and longevity, the elevation of BDNF by treatment with GA, combined with our finding of correlation between "less effective" BDNF polymorphism, disease severity and seizure onset, further indicates that GA may affect positively also other symptoms such as seizures, development of scoliosis, learning- and anxiety -related behaviors and social interaction in Rett patients.

For measurement of neurobehavioral and other aspects including locomotor behavior, cognitive behavior, and social interaction behavior, body weight, breathing pattern, seizure activity, and longevity, methods well-known in the art can be used. Specific tests may include, without limitation, the dark cycle running wheel activity assay (as described by Chang et al., 2006), in which running wheel activity of mice is recorded in the dark, as mice are nocturnal. Mice with symptoms of RTT show decreased running wheel activity and administration of GA is expected to comparatively increase such activity, possibly to a normal or near normal level as typically seen in mice without RTT symptoms.

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Claims

1. An active agent selected from Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for use in the treatment of a neurodevelopmental disorder.

2. The active agent according to claim 1, wherein said Copolymer 1 or Copolymer 1 -related peptide or polypeptide is a random copolymer that cross-reacts functionally with myelin basic protein (MBP) and is capable of competing with MBP on the MHC class II molecule in antigen presentation.

3. The active agent according to claim 2, wherein said random copolymer comprises one amino acid residue selected from each of at least three of the following groups: (a) lysine and arginine; (b) glutamic acid and aspartic acid; (c) alanine, valine and glycine; and (d) tyrosine, phenylalanine and tryptophan.

4. The active agent according to claim 3, wherein said random copolymer consists of four different amino acid residues, each from a different one of the groups (a) to (d).

5. The active agent according to claim 4, wherein said four different amino acid residues are alanine, glutamic acid, lysine and tyrosine.

6. The active agent according to claim 5, wherein said copolymer has a net overall positive electrical charge and a molecular weight of about 2,000 to about

40,000 daltons.

7. The active agent according to claim 6, wherein said copolymer consists of the four different amino acid residues alanine, glutamic acid, lysine and tyrosine in the molar ratios of about 0.14 glutamic acid, about 0.43 alanine, about 0.10 tyrosine and about 0.33 lysine.

8. The active agent according to claim 1, wherein said copolymer is glatiramer acetate.

9. The active agent according to claim 3, wherein said random copolymer is a terpolymer consisting of three different amino acid residues, each from a different one of three groups (a) to (d).

10. The active agent according to claim 9, wherein said three different amino acid residues are tyrosine, alanine, and lysine; tyrosine, glutamic acid and lysine; .lysine, glutamic acid, and alanine; or tyrosine, glutamic acid, and alanine.

11. The active agent according to any of claims 1 to 10, wherein the amino acids are selected from the group consisting of: L- amino acids, D- amino acids and a mixture of L- and D-amino acids.

12. The active agent according to claim 1, wherein said Copolymer 1-related peptide is selected from SEQ ID NOS: 1-32.

13. The active agent according to any of claims 1 to 12, wherein said neurodevelopmental disorder is Rett (RTT) syndrome, autism and autism spectrum disorders, various syndromes which result in mental retardation such as Down's syndrome and Fragile X syndrome, and/or other types of mental deficiencies.

14. The active agent according to claim 13, wherein said neurodevelopmental disorder is Rett (RTT) syndrome.

15. Use of an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 -related polypeptide, or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for the treatment of a neurodevelopmental disorder.

16. A pharmaceutical composition for treatment of a neurodevelopmental disorder, comprising an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related-peptide and a Copolymer 1 related polypeptide, or a pharmaceutically acceptable salt thereof, and a pharmaceutically active carrier or excipient.

17. A method for treatment of a neurodevelopmental disorder, comprising administering to an individual in need a therapeutically active amount of an active agent selected from the group consisting of Copolymer 1, a Copolymer 1 related- peptide and a Copolymer 1 related polypeptide, or a pharmaceutically acceptable salt thereof.

18. The method according to claim 17, for treatment of a Rett syndrome patient for preventing, reversing, attenuating, alleviating, minimizing, suppressing or halting at least some of the symptoms/deleterious effects caused by or associated with the disorder.