WO2017168137A1

WO2017168137A1 - Pyrimidobenzimidazoles for use in the treatment and prevention of neurodegenerative disorders

Info

Publication number: WO2017168137A1
Application number: PCT/GB2017/050866
Authority: WO
Inventors: Pavel Pavlov; Bengt Winblad
Original assignee: Great Matter Pharma AB
Current assignee: Great Matter Pharma AB
Priority date: 2016-03-29
Filing date: 2017-03-28
Publication date: 2017-10-05
Anticipated expiration: 2018-09-29
Also published as: GB201605217D0; GB2548839B; GB2548839A

Abstract

There is provided herein a compound of formula I (I) or a tautomer and/or pharmaceutically acceptable salt thereof, for use in the treatment or prevention of a neurodegenerative disorder, wherein X, Y, Z, R¹, R² and n have meanings as provided in the description.

Description

PYRIM I DOBENZI IMIDAZOLES FOR USE IN THE TREATMENT AND PREVENTION OF NEURODEGENERATIVE DISORDERS

Field of the Invention

The present invention relates to the treatment and prevention of neurodegenerative disorders. In particular, it relates to the use of pyrimido[1 ,2-a]benzimidazoles, and analogues thereof, in the treatment of disorders such as Alzheimer's disease and other neurodegenerative disorders.

Background of the Invention

The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Neurodegeneration is a general term referring to conditions characterised by the progressive loss of structure or function of neurons, which may also be characterised by neuron death. Many diseases are characterised by neurodegeneration, including well- known conditions such as Alzheimer's disease and Parkinson's disease. At present, such diseases are thought to be incurable, with the progressive worsening of neuron damage eventually leading to death of the patient.

Neurodegenerative diseases (NDDs) are characterized by an enormous unmet medical need and, unfortunately, no effective treatments. The limited success in therapeutic development is linked to complex and poorly understood pathogenesis, limited effectiveness of single target treatment approaches, and general challenges with drug development for central nervous system (CNS) disorders. These challenges require innovation at several levels of translational neuroscience and CNS drug discovery, including identifying novel targeting mechanisms and therapeutic concepts.

More recently, it has been noted that, particularly on a sub-cellular level, NDDs share many common characteristics. Targeting these similarities provides the potential for the development of treatments that could ameliorate many diseases simultaneously. For example, there are many parallels between different neurodegenerative disorders including atypical protein assemblies as well as induced cell death. Nonetheless, due to the complexity of the pathogenesis of NDDs, the identification of suitable therapeutic targets has provided troublesome and several aspects of the disease pathology have been investigated, such as the following. Mitochondrial dysfunction in NDD

The neuronal function is critically dependent on the energy supply provided by mitochondrial oxidative phosphorylation. The mitochondrial dysfunction and oxidative stress are one of the earliest events that occur in brain as well as in peripheral tissues of NDD patients. Proteins implicated in various NDDs as causative factors were found to be physically associated with mitochondria resulting in impairment of mitochondrial function (see, for example, Anandatheerthavarada, H. K, et. a/., J. Cell Biol., 161 , 41-54 (2003), Pavlov, P.F. et. ai , FASEB J., 25, 78-88 (201 1), Devi, L. et al. , J Biol Chem., 283, 9089- 1000 (2008), Yano, H. et. ai , Nat Neurosci., 17, 822-831 (2014) and Liu, J. et al., Neuron, 43, 5-17 (2004)).

Role of cvtosolic molecular chaperones in protein import into mitochondria

Nuclear-encoded proteins destined for mitochondria enter the organelle via the translocase of the outer membrane (TOM) complex consisting of the protein-conducting channel formed by the central β-barrel protein Tom40, two primary receptors, Tom20 and Tom70, receptor Tom22 and several adaptor subunits of small molecular mass. Molecular chaperones Hsp70 and Hsp90, as well as specific factors in cytosol, participate in targeting of newly synthesised proteins to mitochondrial TOM complex. The specificity of Hsp70 and Hsp90 action is mediated by their co-chaperones and adaptor proteins. Components of mitochondrial translocase machinery, Tom34 and Tom70, interact with molecular chaperones Hsp70 and Hsp90 via tetratricopeptide (TPR) domain mediating mitochondrial import of subset of proteins (see, for example, Young, J.C. et ai, Cell, 112, 41-50 (2003), Faou P & Hoogenraad, N. J., Biochim Biophys Acta., 1823, 348-357 (2012)). In humans, around 20 different proteins containing tetratricopeptide motif (TPR), including Tom34 and Tom70, interact with Hsp70 and Hsp90 via a unique mechanism. Hsp70/Hsp90 localized in cytosol contain C-terminal sequences -E-E-V-D that are necessary and sufficient for their interaction with the TPR domain of co-chaperones.

Role of molecular chaperones in neurodegeneration

Most of NDD can be classified as proteinopathies or protein misfolding disorders with intra- or extracellular aggregation of certain proteins or peptides observed in affected brain areas. Molecular chaperones are primarily responsible for the maintenance of correct conformation of other protein molecules. Furthermore molecular chaperones are responsible for the intracellular protein transport, degradation of damaged or misfolded proteins. An increasing body of evidence suggests an important role for Hsp70/Hsp90 chaperones in various neurodegenerative disorders, particularly in buffering the transition state between soluble and aggregated state of disease related proteins. This may explain the neuroprotective effect of molecular chaperone inhibitors in different models of neurodegeneration. However, it might be expected that long-term therapy for neurodegenerative diseases through the general inhibition or activation of molecular chaperone function could be detrimental. Several TPR co-chaperones have been implicated in the development of Alzheimer's disease and tauopathies. For example, it has been suggested that strategies aimed at attenuating FKBP51 protein levels or its interaction with Hsp90 have the potential to be therapeutically relevant for AD and other tauopathies (see, for example, Blair, L.J. et. al., J Clin Invest, 123, 4158-4169 (2013)).

Another approach to regulate tau phosphorylation is activation of protein phosphatase 5 (PP5). PP5 can dephosphorylate tau and its activity is decreased in AD patients (Liu F, et al., J Biol Chem., 280, 1790-1796 (2005)). PP5 resides in cytoplasm in an inactive form and is activated upon binding to Hsp90 (Yang J, et al., EMBO J., 12, 1-10 (2005)).

Molecules preventing interaction of PP5 with Hsp90 increase phosphatase activity (see, for example, Cher C et al., Appl Biochem Biotechnol., 160, 1450-1459 (2010)). Small glutamine-rich TPR protein (SGTA) is a TPR co-chaperone implicated into Αβ metabolism and it has been found that inactivation of SGTA homologue in C. elegans protected transgenic nematode against Αβ toxicity (see, for example, Fonte, V. et al., Proc Natl Acad Sci U S A., 99, 9439-9444 (2002)).

Role of transition metals dvs-regulation in pathogenesis of NDDs

Compelling evidence suggests a critical role of copper and zinc in both precipitating in and potentiating NDDs (see Adlard, P.A. and Bush, A. I., Front. Psychiatry, 3, 15 (2012)).

Altered metal homeostasis contributes to the loss of neurons from a complex interplay of factors including oxidative injury, excitotoxic stimulation, dysfunction of critical proteins and mitochondrial failure. Attempts to modulate metal homeostasis in NDDs are an emerging therapeutic strategy. Series of 8-hydroxyquinoline analogues have shown the greatest potential for the treatment of several NDDs, including Alzheimer's disease and Parkinson's disease. Two of these, clioquinol and PBT2, have shown promising results in several phase 2 clinical trials for NDDs (see Adlard, P. A. et ai, Neuron., 59, 43-55 (2008)).

However, 8-hydroxyquinoline analogues are able to bind virtually all transition metals with high potency, providing a mechanism for potential undesirable side effects associated with depletion of essential trace metals. For example, the mechanism of toxicity of clioquinol was attributed to the depletion of vitamin B12 (cobalamin) (see Yassin, M.S. et al., J Neurol Sci., 173, 40-44 (2000)). Therefore chronic, potentially life-long treatment of NDDs would require more specific modulation of metal levels in the brain.

Despite the recognition of various potential therapeutic targets, there remains a need for new and effective treatments for NDDs, such as Alzheimer's disease. Ideally, these targets should allow for treatments that target a wide range of NDDs, safely and with low levels of side effects.

Description of the Invention

We have now surprisingly found that certain pyrimido[1 ,2-a]benzimidazoles, and analogues thereof, may possess a range of activities useful in the treatment or prevention of neurodegenerative disorders, such as Alzheimer's disease and amyotrophic lateral sclerosis.

Compounds for medical use In a first aspect of the invention, there is provided a compound of formula I

or a tautomer and/or pharmaceutically acceptable salt thereof, for use in the treatment or prevention of a neurodegenerative disorder, wherein: either X represents NR³ and the dashed bond by which it is bound represents a single bond, and Y represents N and the dashed bond by which it is bound represents a double bond, or X represents N and the dashed bond by which it is bound represents a double bond, and Y represents NR⁴ and the dashed bond by which it is bound represents a single bond; R¹ represents H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -N(R^a3)R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a11 , Ci-e alkyl optionally substituted with one or more R^a12, aryl optionally substituted with one or more G¹ or heteroaryl optionally substituted with one or more G², R² represents H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -N(R^a3)R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a11 , Ci-e alkyl optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G\ or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, aryl optionally substituted by one or more G³, heteroaryl substituted by one or more G⁴, or a 5- to 6-membered alkyl ring, which ring optionally contains one or two heteroatoms and which ring is optionally substituted by one or more

E¹ ; where present, R³ represents H, halo, -CN, -N0₂, -OR^b1 , -S(0)_PR^b2, -N(R^b3)R^b4, -S(0)_qN(R^b5)R^b6, -C(0)N(R^b7)R^b8, -OC(0)N(R^b9)R^b1°, -C(0)OR^b11 , Ci-e alkyl optionally substituted with one or more R^b12, aryl optionally substituted with one or more G⁵ or heteroaryl optionally substituted with one or more G⁶; where present, R⁴ represents H, halo, -CN, -N0₂, -OR^c1 , -S(0)_PR^c2, -NCR^R⁰⁴, -S(0)_qN(R^c5)R^c6, -C(0)N(R^c7)R^c8, -OC(0)N(R^c9)R^c1°, -C(0)OR^c11 , Ci-₆ alkyl optionally substituted with one or more R^c12, aryl optionally substituted with one or more G⁷ or heteroaryl optionally substituted with one or more G⁸; each Z independently represents halo, -CN, -N0₂, -OR^d1 , -S(0)_PR^d2, -N(R^d3)R^d4, -S(0)_qN(R^d5)R^d6, -C(0)N(R^d7)R^d8, -OC(0)N(R^d9)R^d1°, -C(0)OR^d11 , Ci-e alkyl optionally substituted with one or more R^d12, aryl optionally substituted with one or more G⁹ or heteroaryl optionally substituted with one or more G¹⁰; each R^a1 to R^a1\ R^b1 to R^b1\ R^c1 to R^c11 and R^d1 to R^d11 independently represent H, Ci-₆ alkyl optionally substituted with one or more E², aryl optionally substituted with one or more G¹¹ or heteroaryl optionally substituted with one or more G¹²; or alternatively each of R^a3 and R^a4, R^a5 and R^a6, R^a7 and R^a8, R^a9 and R^a1°, R^b3 and R^b4,

g_{nd R}<* g_nd

R^d3 and R^d4, R^d5 and R^d6, R^d7 and R^d8, and R^d9 and R^d1° may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E³; each R^a12, R^b12, R^c12 and R^d12 independently represents oxy, halo, -CN, -N0₂, -OR^e1 , -SR^e2, -N(R^e2)R^e3, -C(0)OR^e5, aryl optionally substituted with one or more G¹³ or heteroaryl optionally substituted with one or more G¹⁴; each R^e1 to R^e5 independently represent Ci-e alkyl optionally substituted with one or more E⁴, aryl optionally substituted with one or more G¹⁵ or heteroaryl optionally substituted with one or more G¹⁶; or alternatively R^e3 and R^e4 may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E⁵; each G¹ to G¹⁶ independently represents oxy, halo, -CN, -N0₂, -OR^f1 , -SR^f2, -N(R^f3)R^M, -C(0)OR^f5, Ci-e alkyl optionally substituted with one or more E⁶; each R^f1 to R^f5 independently represent H or Ci-e alkyl optionally substituted with one or more E⁷, or alternatively R^f3 and R^M may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E⁸; each E¹ to E⁸ independently represents oxy, halo, -CN, -N0₂, -OR⁹¹ , -SR⁹², -N(R⁹²)R⁹³ or -C(0)OR⁹⁵; each R⁹¹ to R⁹⁵ independently represents H or C1-3 alkyl optionally substituted with one or more fluoro; n represents 0 to 4; and p represents 0, 1 or 2, which compounds (including tautomers and pharmaceutically acceptable salts) may be referred to herein as the "compounds of the invention".

In an alternative first aspect of the invention, there is provided the use of a compound of formula I (as described herein), or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for use in the treatment or prevention of a neurodegenerative disorder.

In a further alternative first aspect of the invention, there is provided a method of treating or preventing a neurodegenerative disorder comprising administering to a patient in need thereof a therapeutically effective amount of a compound of formula I (as described herein), or a pharmaceutically acceptable salt thereof.

For the avoidance of doubt, the skilled person will understand that references herein to compounds of particular aspects of the invention (such as the first aspect of the invention, e.g. compounds of formula I) will include references to all embodiments and particular features thereof, which embodiments and particular features may be taken in combination to form further embodiments.

Unless indicated otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

Pharmaceutically acceptable salts include acid addition salts and base addition salts. Such salts may be formed by conventional means, for example by reaction of a free acid or a free base form of a compound of the invention with one or more equivalents of an appropriate acid or base, optionally in a solvent, or in a medium in which the salt is insoluble, followed by removal of said solvent, or said medium, using standard techniques (e.g. in vacuo, by freeze-drying or by filtration). Salts may also be prepared by exchanging a counter-ion of a compound of the invention in the form of a salt with another counter-ion, for example using a suitable ion exchange resin.

Particular acid addition salts that may be mentioned include carboxylate salts (e.g. formate, acetate, trifluoroacetate, propionate, isobutyrate, heptanoate, decanoate, caprate, caprylate, stearate, acrylate, caproate, propiolate, ascorbate, citrate, glucuronate, glutamate, glycolate, a-hydroxybutyrate, lactate, tartrate, phenylacetate, mandelate, phenylpropionate, phenylbutyrate, benzoate, chlorobenzoate, methylbenzoate, hydroxybenzoate, methoxybenzoate, dinitrobenzoate, o-acetoxybenzoate, salicylate, nicotinate, isonicotinate, cinnamate, oxalate, malonate, succinate, suberate, sebacate, fumarate, malate, maleate, hydroxymaleate, hippurate, phthalate or terephthalate salts), halide salts (e.g. chloride, bromide or iodide salts), sulphonate salts (e.g. benzenesulphonate, methyl-, bromo- or chloro-benzenesulphonate, xylenesulphonate, methanesulphonate, ethanesulphonate, propanesulphonate, hydroxyethanesulphonate, 1- or 2- naphthalene-sulphonate or 1 ,5-naphthalenedisulphonate salts) or sulphate, pyrosulphate, bisulphate, sulphite, bisulphite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate or nitrate salts, and the like.

Particular base addition salts that may be mentioned include salts formed with alkali metals (such as Na and K salts), alkaline earth metals (such as Mg and Ca salts), organic bases (such as ethanolamine, diethanolamine, triethanolamine, tromethamine and lysine) and inorganic bases (such as ammonia and aluminium hydroxide). More particularly, base addition salts that may be mentioned include Mg, Ca and, most particularly, K and Na salts.

For the avoidance of doubt, compounds of the first aspect of the invention may exist as solids, and thus the scope of the invention includes all amorphous, crystalline and part crystalline forms thereof, and may also exist as oils. Where compounds of the first aspect of the invention exist in crystalline and part crystalline forms, such forms may include solvates, which are included in the scope of the invention. Compounds of the first aspect of the invention may also exist in solution.

Compounds of the first aspect of the invention may contain double bonds and may thus exist as E (entgegen) and Z (zusammen) geometric isomers about each individual double bond. All such isomers and mixtures thereof are included within the scope of the invention.

Compounds of the first aspect of the invention may also exhibit tautomerism. All tautomeric forms and mixtures thereof are included within the scope of the invention. For example, compounds of formula I wherein X represents NR³ and R³ represents H may also exist in the tautomeric form depicted below:

Similarly, compounds of formula I wherein R² represents OH may also exist in the tautomeric form depicted below:

Compounds of the first aspect of the invention may also contain one or more asymmetric carbon atoms and may therefore exhibit optical and/or diastereoisomerism. Diastereoisomers may be separated using conventional techniques, e.g. chromatography or fractional crystallisation. The various stereoisomers (i.e. enantiomers) may be isolated by separation of a racemic or other mixture of the compounds using conventional, e.g. fractional crystallisation or HPLC, techniques. Alternatively the desired optical isomers may be obtained from appropriate optically active starting materials under conditions which will not cause racemisation or epimerisation (i.e. a 'chiral pool' method), by reaction of the appropriate starting material with a 'chiral auxiliary' which can subsequently be removed at a suitable stage, by derivatisation (i.e. a resolution, including a dynamic resolution); for example, with a homochiral acid followed by separation of the diastereomeric derivatives by conventional means such as chromatography, or by reaction with an appropriate chiral reagent or chiral catalyst all under conditions known to the skilled person. All stereoisomers and mixtures thereof are included within the scope of the invention.

As used herein, references to halo and/or halogen groups will each independently refer to fluoro, chloro, bromo and iodo (for example, fluoro (F) and chloro (CI)), such as flouro.

As used herein, the term oxy will be understood to refer to a =0 (i.e. carbonyl) group. The skilled person will understand that, where present as a substituent on alkyl groups, such oxy groups may be present as substituents on any suitable carbon atom (i.e. a carbon atom able to form a double bond with the required oxygen atom).

Unless otherwise specified, Ci_-Z alkyl groups (where z is the upper limit of the range) defined herein may be straight-chain or, when there is a sufficient number (i.e. a minimum of three) of carbon atoms, be branched-chain, and/or cyclic (so forming a C3-_z-cycloalkyl group). When there is a sufficient number (i.e. a minimum of four) of carbon atoms, such groups may also be part cyclic. For example, part cyclic alkyl groups may include cyclopropylmethyl and the like. When there is a sufficient number of carbon atoms, such groups may also be multicyclic (e.g. bicyclic or tricyclic) or spirocyclic. Such alkyl groups may also be saturated or, when there is a sufficient number (i.e. a minimum of two) of carbon atoms, be unsaturated (forming, for example, a C2 alkenyl or a C2 alkynyl group).

For the avoidance of doubt, references to polycyclic (e.g. bicyclic or tricyclic) groups (e.g. when employed in the context of cycloalkyi groups) will refer to ring systems wherein at least two scissions would be required to convert such rings into a straight chain, with the minimum number of such scissions corresponding to the number of rings defined (e.g. the term bicyclic may indicate that a minimum of two scissions would be required to convert the rings into a straight chain). For the avoidance of doubt, the term bicyclic (e.g. when employed in the context of alkyl groups) may refer to groups in which the second ring of a two-ring system is formed between two adjacent atoms of the first ring, and may also refer to groups in which two non-adjacent atoms are linked by an alkylene group, which later groups may be referred to as bridged. As used herein, the term aryl includes references to Ce-14 (e.g. Ce-io) aromatic groups. Such groups may be monocyclic or bicyclic and, when bicyclic, be either wholly or partly aromatic. Ce-io aryl groups that may be mentioned include phenyl, naphthyl, 1 ,2,3,4- tetrahydronaphthyl, indanyl, and the like (e.g. phenyl, naphthyl and the like, such as phenyl). At each occurrence, particular aryl groups that may be mentioned include phenyl. For the avoidance of doubt, the point of attachment of substituents on aryl groups may be via any carbon atom of the ring system.

As used herein, the term heteroaryl (or heteroaromatic) includes references to 5- to 14- (e.g. 5- to 10-) membered heteroaromatic groups containing one or more heteroatoms selected from oxygen, nitrogen and/or sulphur. Such heteroaryl groups may comprise one, two, or three rings, of which at least one is aromatic. Substituents on heteroaryl/heteroaromatic groups may, where appropriate, be located on any atom in the ring system including a heteroatom. The point of attachment of heteroaryl/heteroaromatic groups may be via any atom in the ring system including (where appropriate) a heteroatom. Bicyclic heteroaryl/heteroaromatic groups may comprise a benzene ring fused to one or more further aromatic or non-aromatic heterocyclic rings, in which instances, the point of attachment of the polycyclic heteroaryl/heteroaromatic group may be via any ring including the benzene ring or the heteroaryl/heteroaromatic or heterocycloalkyl ring. Examples of heteroaryl/heteroaromatic groups that may be mentioned include pyridinyl, pyrrolyl, furanyl, thiophenyl, oxadiazolyl, thiadiazolyl, thiazolyl, oxazolyl, pyrazolyl, triazolyl, tetrazolyl, isoxazolyl, isothiazolyl, imidazolyl, imidazopyrimidinyl, imidazothiazolyl, thienothiophenyl, pyrimidinyl, furopyridinyl, indolyl, azaindolyl, pyrazinyl, pyrazolopyrimidinyl, indazolyl, pyrimidinyl, quinolinyl, isoquinolinyl, quinazolinyl, benzofuranyl, benzothiophenyl, benzoimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl and purinyl. The oxides of heteroaryl/ heteroaromatic groups are also embraced within the scope of the invention (e.g. the /V-oxide). As stated above, heteroaryl includes polycyclic (e.g. bicyclic) groups in which one ring is aromatic (and the other may or may not be aromatic). Hence, other heteroaryl groups that may be mentioned include e.g. benzo[1 ,3]dioxolyl, benzo[1 ,4]dioxinyl, dihydrobenzo[d]isothiazole, 3,4-dihydrobenz[1 ,4]oxazinyl, dihydrobenzothiophenyl, indolinyl, 5/-/,6/-/, 7/-/-pyrrolo[1 ,2- /5]pyrimidinyl, 1 ,2,3,4-tetrahydroquinolinyl, thiochromanyl and the like.

Particular heteroaryl groups that may be mentioned include pyridinyl (e.g. pyridine-2-yl), thiadiazolyl (e.g. 1 ,3,4-thiadiazolyl, such as 1 ,3,4-thiadiazol-2-yl) and benzothiazolyl (e.g. 1 ,3-benzothiazolyl, such as 1 ,3-benzothiazol-2-yl). As indicated herein, certain substituents may be joined, together with the atoms to which they are attached, to form rings alkyl rings having a particular number of ring members, which rings may necessary or optionally comprise one or more heteroatoms. In such cases, the skilled person will understand that references to such rings as alkyl rings will indicate the components of the ring other than the relevant heteroatom(s) are alkyl. For the avoidance of doubt, all atoms linked so as to form the ring, whether carbon atoms or heteroatoms, may be counted as a ring member.

For the avoidance of doubt, as used herein, references to heteroatoms will take their normal meaning as understood by one skilled in the art. Particular heteroatoms that may be mentioned include phosphorus, selenium, tellurium, silicon, boron, oxygen, nitrogen and sulphur (e.g. oxygen, nitrogen and sulphur, such as oxygen and nitrogen).

The present invention also embraces isotopically-labelled compounds of the present invention which are identical to those recited herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature (or the most abundant one found in nature). All isotopes of any particular atom or element as specified herein are contemplated within the scope of the compounds of the invention. Hence, the compounds of the invention also include deuterated compounds, i.e. in which one or more hydrogen atoms are replaced by the hydrogen isotope deuterium. For the avoidance of doubt, in cases in which the identity of two or more substituents in a compound of the invention may be the same, the actual identities of the respective substituents are not in any way interdependent. For example, in the situation in which two or more Z groups are present, those Z groups may be the same or different. Similarly, where two or more X groups are present and each represent halo, the halo groups in question may be the same or different. Likewise, when more than one -OR^a1 is present and each R^a1 represents a Ci-e alkyl group, those Ci-e alkyl groups, including any substituents thereon, may be the same or different.

The skilled person will appreciate that compounds of the invention that are the subject of this invention include those that are stable. That is, compounds of the invention include those that are sufficiently robust to survive isolation, e.g. from a reaction mixture, to a useful degree of purity.

Also described herein (e.g. for reference purposes), in relation to each disclosure of a compound of formula I as provided herein (e.g. in the first aspect of the invention, including all embodiments thereof) there is also provided a corresponding disclosure but wherein:

R¹ and R² each independently represent H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -N(R^a3)R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a11 , Ci-e alkyl optionally substituted with one or more R^a12, aryl optionally substituted with one or more G¹ or heteroaryl optionally substituted with one or more G², or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, aryl optionally substituted by one or more G³, heteroaryl substituted by one or more G⁴, or a 5- to 6-membered alkyl ring, which ring optionally contains one or two heteroatoms and which ring is optionally substituted by one or more E¹.

In particular embodiments of the first aspect of the invention: R¹ and R² each independently represent H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -N(R^a3)R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a11 , Ci-e alkyl optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G¹ , or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, aryl optionally substituted by one or more G³, heteroaryl substituted by one or more G⁴, or a 5- to 6-membered alkyl ring, which ring optionally contains one or two heteroatoms and which ring is optionally substituted by one or more E¹.

In more particular embodiments of the first aspect of the invention:

R¹ and R² each independently represent H, halo (e.g. fluoro), -OR^a1 , -C(0)OR^a1\ Ci_-6 alkyl optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G\ or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl (i.e. a phenyl ring) optionally substituted by one or more G³.

In yet more particular embodiments:

R¹ and R² each independently represent H, halo (e.g. fluoro), -OR^a1 , -C(0)OR^a11 , Ci-e alkyl (e.g. Ci-5 alkyl) optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G¹, or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl (i.e. a phenyl ring). In certain embodiments:

R^a12 represents oxy, halo (e.g. fluoro), -CN, -OR^e1 , -SR^e2, -C(0)OR^e5 or aryl optionally substituted with one or more G¹³. Thus, in particular embodiments: R¹ and R² each independently represent H, -OH, -C(0)OCi-₃ alkyl (e.g. -C(0)OCi-₂ alkyl), C1-6 alkyl (e.g. C1-5 alkyl) optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G¹ , or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl (i.e. a phenyl ring);

R^a12 represents oxy, halo (e.g. fluoro), -CN, -OR⁹¹ , -SR^e2, -C(0)OR^e5 or phenyl optionally substituted with one or more G¹³;

R^e1 represents C1-3 alkyl optionally substituted with one or more fluoro (e.g. methyl);

R^e2 represents phenyl optionally substituted with one or more halo (e.g. chloro) or C1-3 alkyl (e.g. methyl) group, or heteroaryl optionally substituted with one or more halo (e.g. chloro) or C1-3 alkyl (e.g. methyl) group;

R^e5 represents H or C1-3 alkyl (e.g. C1-2 alkyl, such as ethyl); and/or (e.g. and)

G¹³ represents a halo (e.g. fluoro or chloro) or -OC1-3 alkyl (e.g. -OCH3) group.

In more particular embodiments:

R¹ and R² each independently represent H or C1-6 alkyl (e.g. C1-3 alkyl, such as Ci alkyl) optionally substituted with one or more R^a12;

R^a12 represents halo (e.g. fluoro) or -OR^e1 ; and

R^e1 represents C1-3 alkyl optionally substituted with one or more fluoro (e.g. methyl). Particular R¹ groups that may be mentioned include H.

Particular R² groups that may be mentioned include H, methyl and -CH2OCH3. More particular R² groups that may be mentioned include -CH2OCH3. Particular compounds of formula I that may be mentioned include those in which X represents NR³ and the dashed bond by which it is bound represents a single bond, and Y represents N and the dashed bond by which it is bound represents a double bond. Thus, in particular embodiments, the compound of formula I is represented by a compound of formula la

wherein R¹ to R³, Z and n are as defined herein.

In particular embodiments, R³ represents H or Ci-e alkyl optionally substituted with one or more R^b12. In particular embodiments:

R³ represents H or Ci-e alkyl (e.g. C1-3 alkyl) optionally substituted with one or more R^b12; and R^b12 represents oxy, halo (e.g. fluoro), -CN or phenyl optionally substituted by one or more halo (e.g fluoro).

In more particular embodiments: R³ represents H or C1-3 alkyl optionally substituted with one or more R^b12; and

R^b12 represents oxy, -CN or phenyl.

Particular R³ groups that may be mentioned include H.

Particular compounds of formula I that may be mentioned include those in which X represents N and the dashed bond by which it is bound represents a double bond, and Y represents NR⁴ and the dashed bond by which it is bound represents a single bond. Thus, in particular embodiments, the compound of formula I is represented by a compound of formula lb

wherein R¹ , R², R⁴, Z and n are as defined herein.

In particular embodiments, R⁴ represents Ci-e alkyi (e.g. C1-5 alkyi) optionally substituted with one or more R^c12.

In more particular embodiments:

R⁴ represents C1-6 alkyi (e.g. C1-5 alkyi) optionally substituted with one or more R^c12; and R^c12 represents phenyl optionally substituted with one or more halo (e.g. fluoro) or C1-3 alkyi (Ci alkyi) optionally substituted with one or more halo (e.g. fluoro).

In more particular embodiments: Z represents halo (e.g. fluoro) or C1-3 alkyi (e.g. methyl) optionally substituted with one or more halo (e.g. fluoro); and/or n represents 0 or 1. In more particular embodiments:

Z represents fluoro; and/or n represents 0 or 1.

In yet more particular embodiments, n represents 0. In particular embodiments, p represents 0. As described herein, all embodiments of the invention and particular features mentioned herein may be taken in isolation or in combination with any other embodiments and/or particular features mentioned herein (hence describing more particular embodiments and particular features as disclosed herein) without departing from the disclosure of the invention.

Thus, in particular embodiments that may be mentioned:

R¹ and R² each independently represent H, -OH, -C(0)OCi-₃ alkyl (e.g. -C(0)OCi-₂ alkyl), Ci-6 alkyl (e.g. C1-5 alkyl) optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G\ or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl (i.e. a phenyl ring);

R^e2 represents phenyl optionally substituted with one or more halo (e.g. chloro) or C1-3 alkyl (e.g. methyl) group, or heteroaryl optionally substituted with one or more halo (e.g. chloro) or C1-3 alkyl (e.g. methyl) group; R^e5 represents H or C1-3 alkyl (e.g. C1-2 alkyl, such as ethyl);

G¹³ represents a halo (e.g. fluoro or chloro) or -OC1-3 alkyl (e.g. -OCH3) group;

R³ represents H or C1-6 alkyl (e.g. C1-3 alkyl) optionally substituted with one or more R^b12;

R^b12 represents oxy, halo (e.g. fluoro), -CN or phenyl optionally substituted by one or more halo (e.g fluoro);

R⁴ represents C1-6 alkyl (e.g. C1-5 alkyl) optionally substituted with one or more R^c12;

R^c12 represents phenyl optionally substituted with one or more halo (e.g. fluoro) or C1-3 alkyl (Ci alkyl) optionally substituted with one or more halo (e.g. fluoro); Z represents halo (e.g. fluoro); and/or (e.g. and) n represents 0 or 1.

In more particular embodiments that may be mentioned:

R¹ and R² each independently represent H or Ci-e alkyi (e.g. C1-3 alkyi, such as Ci alkyi) optionally substituted with one or more R^a12;

R^a12 represents halo (e.g. fluoro) or -OR^e1 ;

R^e1 represents C1-3 alkyi optionally substituted with one or more fluoro (e.g. methyl); R³ represents H or C1-3 alkyi optionally substituted with one or more R^b6; R^b12 represents oxy, -CN or phenyl;

R⁴ represents C1-6 alkyi (e.g. C1-5 alkyi) optionally substituted with one or more R^c12;

R^c12 represents phenyl optionally substituted with one or more halo (e.g. fluoro) or C1-3 alkyi (Ci alkyi) optionally substituted with one or more halo (e.g. fluoro); and/or (e.g. and) n represents 0.

In yet more particular embodiments that may be mentioned:

X represents NR³ and the dashed bond by which it is bound represents a single bond, and Y represents N and the dashed bond by which it is bound represents a double bond (i.e. the compound of formula I is a compound formula la);

R¹ and R² each independently represent H or C1-6 alkyi (e.g. C1-3 alkyi, such as Ci alkyi) optionally substituted with one or more R^a12; R^a12 represents halo (e.g. fluoro) or -OR^e1 ; and

R^e1 represents C1-3 alkyi optionally substituted with one or more fluoro (e.g. methyl); R³ represents H; and n represents 0.

Particular compounds of formula I that may be mentioned include the compounds of the examples as provided herein below.

More particular compounds of formula I that may be mentioned include the compounds described in Example 1 as provided herein below (such as Compounds 1 to 4, e.g. Compound 4).

The skilled person will understand that references to the treatment of a particular medical condition (or, similarly, to treating that condition) take their normal meanings in the field of medicine. In particular, the term may refer to achieving a reduction in the severity of one or more clinical symptom associated with the relevant condition.

For example, in relation to the treatment of Alzheimer's disease, references to treating the condition may refer to achieving a reduction in cognitive decline, which may be measured using cognitive tests as known to those skilled in the art. Moreover, such treatment may also be measured through analysis of relevant biomarkers as known to those skilled in the art, such as through analysis of brain oxygen consumption using routine techniques (e.g. PET scanning). The skilled person will be aware of various ways in which Alzheimer's disease and an effect in the treatment thereof may be identified (see, for example, Winblad, B. et ai, Lancet Neurol., 15, 455-532 (2016)).

The skilled person will understand that references to the prevention of a particular condition (or, similarly, to preventing that condition) take their normal meanings in the field of medicine. In particular, the term may refer to achieving a reduction in the likelihood of a subject developing the condition (which may be observed as the development of one or more clinical symptom associated with the relevant condition), such as a reduction of at least 10% (e.g. at least 30%, such as at least 50%).

As used herein, references to prevention (e.g. of a particular medical condition) may also be referred to as prophylaxis. At each occurrence herein, references to the treatment or prevention of a particular condition will refer in particular to the treatment of the condition. Similarly, references to treating or preventing a particular condition will refer in particular to treating the condition. As used herein, references to patients will refer to a living subject in which the relevant treatment or prevention (e.g. treatment) occurs, including mammalian (e.g. human) patients. Thus, in particular embodiments the treatment or prevention (e.g. the treatment) as described herein is in a human. As used herein, the term therapeutically effective amount will refer to an amount of a compound that confers a therapeutic effect on the treated patient. The effect may be objective (i.e. measurable by some test or marker) or subjective (i.e. the subject gives an indication of and/or feels an effect). Although compounds of the invention may possess pharmacological activity as such, certain pharmaceutically-acceptable (e.g. "protected") derivatives of compounds of the invention may exist or be prepared which may not possess such activity, but may be administered (e.g. parenterally or orally) and thereafter be metabolised in the body to form compounds of the invention. Such compounds (which may possess some pharmacological activity, provided that such activity is appreciably lower than that of the active compounds to which they are metabolised) may therefore be described as "prodrugs" of compounds of the invention.

As used herein, references to prodrugs will include compounds that form a compound of the invention, in an experimentally-detectable amount, within a predetermined time, following enteral or parenteral administration (e.g. oral or parenteral administration). All prodrugs of the compounds of the first aspect of the invention are included within the scope of the invention. For the avoidance of doubt, compounds of the invention are useful because they possess pharmacological activity, and/or are metabolised in the body following oral or parenteral administration to form compounds that possess pharmacological activity. In particular, as described herein, compounds of the first aspect of the invention are useful in the treatment or prevention of neurodegenerative disorders, which term will be readily understood by one of skill in the art. In particular, the skilled person will understand that the term neurodegenertive disorder may refer to disorders (which may also be referred to as diseases, medical conditions, conditions, or the like) characterised by the progressive loss of structure or function of neurons, which may also be characterised by neuron death.

Neurodegenerative disorders that may be mentioned include Alzheimer's Disease and other dementias (such as fronto-temporal dementia and dementia with Lewy bodies), vascular dementia, traumatic brain injury, brain cancers, degenerative nerve diseases, encephalitis, epilepsy, genetic brain disorders, head and brain malformations, hydrocephalus, stroke, Parkinson's Disease, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS or Lou Gehrig's Disease), Huntington's Disease and prion diseases (such as Creutzfeld-Jacob disease (CJD)).

Particular neurodegenerative disorders that may be mentioned include Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis.

In a particular embodiment, the neurodegenerative disorder is Alzheimer's disease.

Novel compounds and medical uses

Certain compounds of the invention as disclosed herein may be novel and/or not previously disclosed for use in medicine.

Thus, in a second aspect of the invention, there is provided a compound as described in the first aspect of the invention (such as in any embodiment or combination of embodiments thereof).

Further, in a third aspect of the invention, there is provided a compound as described in the first aspect of the invention (such as in any embodiment or combination of embodiments thereof) for use in medicine (or as a pharmaceutical).

Pharmaceutical compositions

The skilled person will understand that compounds of the first aspect of the invention may be administered alone or may be administered by way of known pharmaceutical compositions/formulations. Moreover, the skilled person will understand that references herein to compounds of the invention being for particular uses (and, similarly, to uses and methods of use relating to compounds of the invention) may also apply to pharmaceutical compositions comprising compounds of the invention as described herein.

In a fourth aspect of the invention, there is provided a pharmaceutical composition comprising a compound as defined in first aspect of the invention, and optionally one or more pharmaceutically acceptable adjuvant, diluent and/or carrier, for use in the treatment or prevention of a neurodegenerative disorder (as described herein).

In an alternative fourth aspect of the invention, there is provided a method of treating or preventing a neurodegenerative disorder (as described herein) comprising administering to a patient in need thereof a therapeutically effective amount of a pharmaceutical composition comprising a compound as defined in first aspect of the invention, and optionally one or more pharmaceutically acceptable adjuvant, diluent and/or carrier.

The skilled person will understand that compounds of the invention may act systemically and/or locally (i.e. at a particular site). In particular, compounds of the invention may act systemically.

The skilled person will understand that compounds and compositions as described herein will normally be administered orally, intravenously, subcutaneously, buccally, rectally, dermally, nasally, tracheally, bronchially, sublingually, intranasally, topically, by any other parenteral route or via inhalation, in a pharmaceutically acceptable dosage form. Pharmaceutical compositions as described herein will include compositions in the form of tablets, capsules or elixirs for oral administration, suppositories for rectal administration, sterile solutions or suspensions for parenteral or intramuscular administration, and the like.

In particular embodiments, the pharmaceutical formulation is provided in a pharmaceutically acceptable dosage form, including tablets or capsules, liquid forms to be taken orally or by injection, suppositories, creams, gels, foams, inhalants (e.g. to be applied intranasally), or forms suitable for topical administration. For the avoidance of doubt, in such embodiments, compounds of the invention may be present as a solid (e.g. a solid dispersion), liquid (e.g. in solution) or in other forms, such as in the form of micelles.

For example, in the preparation of pharmaceutical formulations for oral administration, the compound may be mixed with solid, powdered ingredients such as lactose, saccharose, sorbitol, mannitol, starch, amylopectin, cellulose derivatives, gelatin, or another suitable ingredient, as well as with disintegrating agents and lubricating agents such as magnesium stearate, calcium stearate, sodium stearyl fumarate and polyethylene glycol waxes. The mixture may then be processed into granules or compressed into tablets.

Soft gelatin capsules may be prepared with capsules containing one or more active compounds (e.g. compounds of the first and, therefore, second and third aspects of the invention, and optionally additional therapeutic agents), together with, for example, vegetable oil, fat, or other suitable vehicle for soft gelatin capsules. Similarly, hard gelatine capsules may contain such compound(s) in combination with solid powdered ingredients such as lactose, saccharose, sorbitol, mannitol, potato starch, corn starch, amylopectin, cellulose derivatives or gelatin.

Dosage units for rectal administration may be prepared (i) in the form of suppositories which contain the compound(s) mixed with a neutral fat base; (ii) in the form of a gelatin rectal capsule which contains the active substance in a mixture with a vegetable oil, paraffin oil, or other suitable vehicle for gelatin rectal capsules; (iii) in the form of a ready- made micro enema; or (iv) in the form of a dry micro enema formulation to be reconstituted in a suitable solvent just prior to administration.

Liquid preparations for oral administration may be prepared in the form of syrups or suspensions, e.g. solutions or suspensions, containing the compound(s) and the remainder of the formulation consisting of sugar or sugar alcohols, and a mixture of ethanol, water, glycerol, propylene glycol and polyethylene glycol. If desired, such liquid preparations may contain colouring agents, flavouring agents, saccharine and carboxymethyl cellulose or other thickening agent. Liquid preparations for oral administration may also be prepared in the form of a dry powder to be reconstituted with a suitable solvent prior to use. Solutions for parenteral administration may be prepared as a solution of the compound(s) in a pharmaceutically acceptable solvent. These solutions may also contain stabilizing ingredients and/or buffering ingredients and are dispensed into unit doses in the form of ampoules or vials. Solutions for parenteral administration may also be prepared as a dry preparation to be reconstituted with a suitable solvent extemporaneously before use.

The skilled person will understand that compounds of the invention may be administered (for example, as compositions as described in the fourth aspect of the invention) at varying doses, with suitable doses being readily determined by one of skill in the art. Oral, pulmonary and topical dosages (and subcutaneous dosages, although these dosages may be relatively lower) may range from between about 0.01 mg/kg of body weight per day (mg/kg/day) to about 200 mg/kg/day, preferably about 0.01 to about 10 mg/kg/day, and more preferably about 0.1 to about 5.0 mg/kg/day. For example, when administered orally, treatment with such compounds and compositions may comprise administration of a compositions typically containing between about 0.01 mg to about 2000 mg, for example between about 0.1 mg to about 500 mg, or between 1 mg to about 100 mg, of the active ingredient. When admixture intravenously, the most preferred doses will range from about 0.001 to about 10 mg/kg/hour during constant rate infusion. Advantageously, treatment may comprise administration of such compounds and compositions in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily (with reference to the doses described herein). In any event, the skilled person (e.g. the physician) will be able to determine the actual dosage which will be most suitable for an individual patient, which is likely to vary with the route of administration, the type and severity of the condition that is to be treated, as well as the species, age, weight, sex, renal function, hepatic function and response of the particular patient to be treated. The above-mentioned dosages are exemplary of the average case; there can, of course, be individual instances where higher or lower dosage ranges are merited, and such are within the scope of this invention.

As described herein above, the skilled person will understand that treatment with compounds of the invention may further comprise (i.e. be combined with) further (i.e. additional/other) treatment(s) for the same condition. In particular, treatment with compounds of the invention may be combined with other means for the treatment or prevention of neurodegenerative disorders (as defined herein).

Thus, in a particular embodiment of the first aspect of the invention, the treatment may also comprise treatment with one or more additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder (as defined herein).

In such instances, the skilled person will understand that such other treatments (e.g. other compounds) are administered as part of the same treatment (i.e. within the same treatment program) and may be administered separately (e.g. sequentially) or concomitantly (e.g. as part of the same medical intervention, such as in a single dosage form). Further, in particular embodiments of the fourth aspect of the invention, the pharmaceutical composition may further comprise one or more additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder (as defined herein). As described herein, pharmaceutical compositions comprising compounds of the invention and one or more additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder may be novel.

Thus, in a fifth aspect of the invention, there is provided a pharmaceutical composition comprising a compound as defined in first aspect of the invention, and optionally one or more pharmaceutically acceptable adjuvant, diluent and/or carrier, and an additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder (as defined herein). The skilled person will understand that combinations of therapeutic agents may also described as a combination product and/or provided as a kit-of-parts.

In a sixth aspect of the invention, there is provided a combination product comprising: (A) a compound as defined in the first aspect of the invention; and

(B) one or more additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder (as defined herein),

wherein each of components (A) and (B) is formulated in admixture, optionally with one or more a pharmaceutically-acceptable adjuvant, diluent or carrier. In a seventh aspect of the invention, there is provided a kit-of-parts comprising:

(a) a compound as defined in the first aspect of the invention, or a pharmaceutical composition as defined in the fourth aspect of the invention; and

(b) one or more other therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder (as defined herein), optionally in admixture with one or more pharmaceutically-acceptable adjuvant, diluent or carrier,

which components (a) and (b) are each provided in a form that is suitable for administration in conjunction with the other.

The skilled person will understand that, particularly in relation to the first and fourth aspects of the invention, references to an additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder will refer to a therapeutic agent that is suitable for the treatment or prevention of the neurodegenerative disorder for which the compound or composition is for use in treating or preventing (or the neurodegenerative disorder for which the compound or formulation is to be used in a method of treating or preventing).

For example, the additional therapeutic agent may be a therapeutic agent that is suitable for treating or preventing (e.g. treating) Alzheimer's disease, as known to those skilled in the art, such as acetylcholinesterase inhibitors (e.g. tacrine, rivastigmine, galantamine and donepezil) and NMDA receptor antagonists (e.g. memantine).

Preparation of compounds/compositions

Pharmaceutical compositions/formulations, combination products and kits as described herein may be prepared in accordance with standard and/or accepted pharmaceutical practice. Thus, in further aspects of the invention there is provided a process for the preparation of a pharmaceutical composition/formulation, as hereinbefore defined, which process comprises bringing into association a compound of the invention, as hereinbefore defined, with one or more pharmaceutically-acceptable adjuvant, diluent or carrier. In further aspects of the invention, there is provided a process for the preparation of a combination product or kit-of-parts as hereinbefore defined, which process comprises bringing into association a compound of the invention, as hereinbefore defined, or a pharmaceutically acceptable salt thereof with the other therapeutic agent that is useful in the treatment or prevention of a neurodegenerative disorder (as defined herein), and at least one pharmaceutically-acceptable adjuvant, diluent or carrier.

As used herein, references to bringing into association will mean that the two components are rendered suitable for administration in conjunction with each other. Thus, in relation to the process for the preparation of a kit of parts as hereinbefore defined, by bringing the two components "into association with" each other, it is included that the two components of the kit of parts may be:

(i) provided as separate formulations (i.e. independently of one another), which are subsequently brought together for use in conjunction with each other in combination therapy; or

(ii) packaged and presented together as separate components of a "combination pack" for use in conjunction with each other in combination therapy. Compounds as defined in the first aspect of the invention may be commercially available and/or may be prepared in accordance with techniques that are well known to those skilled in the art.

For example, compounds of the invention may be prepared in accordance with, or by analogy to, the techniques described in US 4,072,679 (the contents of which are incorporated herein by reference) and/or by conventional synthetic procedures, in accordance with standard techniques, from available starting materials using appropriate reagents and reaction conditions. In this respect, the skilled person may refer to inter alia the general synthetic techniques described in: "Comprehensive Organic Synthesis" by B. M. Trost and I. Fleming, Pergamon Press, 1991 ; "Comprehensive Organic Functional Group Transformations" by A. R. Katritzky, O. Meth-Cohn and C. W. Rees, Pergamon Press, 1995; and/or "Comprehensive Organic Transformations" by R. C. Larock, Wiley- VCH, 1999.

The skilled person will understand that compounds of the invention may be isolated from their reaction mixtures and, if necessary, purified using conventional techniques as known to those skilled in the art. The skilled person will also understand that, where compounds of the invention are provided in the form of a pharmaceutically acceptable salt, the required pharmaceutically acceptable salt may be obtained by using routine techniques, such as by reaction of the non-salt form of the compound with an appropriate acid or base.

As described herein, compounds of the invention are thought to be particularly useful in the treatment or prevention of neurodegenerative disorders, and so may be useful in the preparation of pharmaceutical formulations for treating or preventing such disorders. In doing so, compounds of the invention may be more effective and/or deliver low levels of side effects than compounds of the prior art known for the same use. Without wishing to be bound by theory, compounds of the invention as described herein are thought to be useful in the treatment or prevention of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis (AMS), as they may inhibit interactions between recombinant human Tom34 and the C- terminal amino acid residues of human Hsp90 protein, which may in turn act to reduce accumulation of amyloid precursor protein (APP) inside mitochondria, or other proteins shown to be mis-targeted to mitochondria (for example, alpha-synuclein or superoxide dismutase (SOD1)). Further, compounds of the invention may act to bind transition metals, particularly Cu²⁺ and Zn²⁺, which in turn may restore Cu²⁺ inhibited Αβ₄2 fibrillization. Figures

Figure 1A represents a dot-blot assay as described in Example 2.

Figure 1 B represents a concentration-dependent inhibition of Tom34-C90-HRP interactions as described Example 3.

Figure 2A represents results of co-immunoprecipitation assay of SH-SY5Y cell lysate as described in Example 4. Figure 2B represents immunostaining results of fractionated SH-SY5Y cells with 22c1 1 antibodies as described in Example 5.

Figure 3A schematically presents copper/zinc binding site on pyrimido[1 ,2-a]benzimidazol- 4(1 H)-one (Compound 4, also referred to herein as GMP-1), as described below, as described in Example 6

Figure 3B represents absorbance scan of Compound 4, also referred to herein as GMP- 1 , as described in Example 6. Figure 3C represents pH-dependent binding of Compound 4, also referred to herein as GMP-1 , as described in Example 6.

Figure 4A represents SDS-PAGE results of β-casein cleavage as described in Example 7. Figure 4B presents cytochrome oxidase activity measurement in isolated mouse brain mitochondria as described in Example 8.

Figure 4C represents time course of thioflavin T fluorescence measurement of Αβ₄2 as described in Example 9.

Figure 5 provides the results of MTT viability assay of SH-SY5Y cells as described in Example 10. Figure 6A represents results of mobility assay of transgenic drosophila flies as described in Example 11. Figure 6B represents results of a viability assay using flies expressing in the neurons dimer Αβ₄2 peptide connected via linker of 12 amino acids, as described in Example 12.

Figure 7 A represents results of open field test with transgenic AD model (5xFAD) mice as described in Example 13.

Figure 7B represents results of a contextual fear conditioning test as described in Example 14.

Figure 8A represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed to Αβ₄2 (6E10), as described in Example 15.

Figure 8B represents results of western blot analysis of total brain extract or purified mitochondria with 6E10 antibody, as described in Example 16. Figure 9A represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed GFAP protein, as described in Example 17.

Figure 9B represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed CD1 1 b protein, as described in Example 18.

Figure 10 represents analysis of cytochrome oxidase activity in purified mouse brain mitochondria, as described in Example 19.

Figure 1 1 represents survival analysis of transgenic drosophila flies expressing the mutant form of human FUS protein, as described in Example 20.

Abbreviations

Abbreviations as used herein will be known to those skilled in the art. In particular, the following abbreviations may be used herein:

DMEM Dulbecco's modified Eagle's medium DMSO Dimethyl sulfoxide

EDTA Ethylenediaminetetraacetic acid

EST Expressed sequence tag

FBS Fetal bovine serum

GFAP Glial fibrillary acidic protein

IPTG Isopropyl β-D-l-thiogalactopyranoside

MOPS 3-(/V-morpholino)propanesulfonic acid

MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide

PCR Polymerase chain reaction

SDS Sodium dodecyl sulphate

SDS-PAGE Sodium dodecyl sulfate polyacrylamide gel electrophoresis

TBS-T Tris-buffered saline with 0.1 % Tween-20

Tris Tris(hydroxymethyl)aminomethane Examples

The present invention is illustrated by way of the following examples. General Procedures

Unless stated otherwise, basic chemicals were obtained from Sigma-Aldrich, USA.

Pyrimido[1 ,2-a]benzimidazol-4(1 H)-one (Compound 4, also referred to herein as GMP-1), as described below, was synthesized at AKos GmbH, Steinen, Germany. Further example compounds were obtained from Vitas-M Laboratory, Apeldoom, The Netherlands.

Αβ₄2 peptide was purchased from Bachem AG, Switzerland. Peptide corresponding to the 10 utmost C-terminal amino acids of human Hsp90 was obtained from GL Biochem Ltd, Shanghai, China. EZ-link Plus activated peroxidase kit was obtained from Pierce Thermo Scientific Inc. Peptide coupling to activated horse-radish peroxidase (C90-HRP) was performed according to manufacturer^'s protocol. EST clones encoding human Tom34 and Tom70 proteins were obtained from I.M.A.G.E. consortium distributors Source Bioscience, Cambridge, UK. Open reading frame of the Tom34 and Tom70 was PCR amplified and sub-cloned into pGEX-6 plasmid (GE Healthcare, Uppsala, Sweden).

Plasmid was further transformed into BL21 E.coli strain and protein expression was induced by addition of 1 mM IPTG for 2 h. Proteins were purified using Gluthatione Sepharose, GE Healthcare, Uppsala, Sweden. For dot-blot experiments (e.g. in Example 2 below), 1 μg of protein was applied on nitrocellulose membrane (Whatman, Madestone, UK), followed by incubation of membrane in TBS-T buffer supplemented with 5 % milk powder for 30 min, 25 °C. Indicated amounts of Pyrimido[1 ,2-a]benzimidazol-4(1 H)-one (GMP-1) or its derivatives were added from DMSO stock solution and incubation continued for another 30 min. C90-HRP 1 :200 times dilution was added to the membrane for 1 h 25 °C. The membrane was subsequently washed 3 times with TBS-T for 10 min, 25 °C and signals were detected using SuperSignal West Pico enhanced chemiluminescence system (ThermoScientific, Rockford IL, USA). Analysis and quantification was performed using a digital imaging camera (Bio-Rad) with QuantityOne software.

SH-SY5Y human neuroblastoma cells were obtained from the American Tissue Culture Collection, ATCC and maintained in DMEM supplemented with 10% FBS and 1 % penicillin-streptomycin (Gibco/lnvitrogen, Carlsbad, CA, USA). Cells were cultured in 5% CO2 -95% air at 37 °C. Sub-cellular fractionation was performed as described in (Pavlov PF et al, 201 1). For viability assays (e.g. in Example 5 below), cellular toxicity was assessed with MTT Cell Proliferation Kit I, Roche Applied Science, Indianapolis, IN, USA according the manufacturer^'s protocol. Indicated amounts of GMP-1 or its derivatives were added from DMSO stock solution directly to the culture media and incubated for 12 h.

Brain mitochondria were isolated (e.g. for use in western blot analysis, such as in Example 16 below) using differential centrifugation according previously published protocol (Devi, L, Prabhu, B.M., Galati, D. F., Avadhani, N. G. and Anandatheerthavarada, H. K., J Neurosci., 26, 9057-9068 (2006)). Antibodies used in the studies were: 22c11 (MAB348) from Millipore, Temecula, CA, USA, Tom40 (Sc-1 1414) from Santa Cruz Biotechnology (Santa Cruz, CA, USA), anti-APP and amyloid beta (6E10) from Covance, USA, CD11 b (ab75476) and GFAP (ab7260) were from Abeam. Immunoprecipitation was performed from SH-SY5Y cells (0.2 mg of protein) treated with DMSO or 50 μΜ of GMP-1 for 12 h. Cells were scraped from the surface in the presence of TBS with 0.2 % Triton X-100 and protease inhibitor cocktail Roche Applied Science, Indianapolis, IN, USA. After centrifugation at 20,000 x g, 4 °C, supernatant was incubated with 0.05 mg/ml of anti-Tom40 antibodies for 3 h 4°C followed by addition of protein A sepharose (GE Healthcare, Uppsala, Sweden) and incubation for 1 h at 4 °C. After incubation sepharose was pelleted by brief centrifugation and washed three times with TBS buffer. To elute proteins SDS loading buffer was applied for the beads and boiled for 5 min. For co-immunoprecipitation assays immunostaining (e.g. in Examples 4 and 5 below), proteins were resolved by SDS-PAGE, transferred to the nitrocellulose membrane and stained with respective antibodies. For metal binding analysis (e.g. in Example 6 below), compound absorbance spectra were measured with NanoDrop ND-100 spectrophotometer (Saveen). Typically, compound 4, also referred to herein as GMP-1 , was used (0.5 mM in 0.1 M MOPS-KOH pH 7.2).

For determination of compound pH-dependent Cu²7Zn²⁺ binding 0.1 M MOPS-KOH buffers of various pH from 5.0 to 8.0 were used. For metal binding experiments following salts were mixed with Compound 4, also referred to herein as GMP-1 , at equimolar amounts in 0.1 M MOPS-KOH pH 7.5: CuCI₂, ZnS0₄, AlC , NiS0₄, MnCI₂, CoCI₂, FeCI₂, FeC , Pb(N03)₂, CaCI₂, MgCI₂ and absorbance spectra without and with salts were compared.

For β-casein cleavage assays (e.g. in Example 7 below), proteolysis of β-casein with collagenase was performed as following: 0.02 mg/ml of collagenase was incubated with 0.1 % DMSO or with 50 μΜ of EDTA, 50 μΜ compound or 50 μΜ of clioquinol for 30 min, 4 °C. β-casein was added from stock solution of 10 mg/ml to final concentration of 1 mg/ml and incubated for 10 min, 4°C. 2 x SDS sample buffer was added and immediately boiled for 5 min and loaded on SDS-PAGE. Gels were subsequently stained with Coumassie Brilliant Blue R-250 and photographed.

Cytochrome oxidase activity was measured (e.g. in Example 8 and 19 below) by decrease in absorbance of ferrocytochrome c at 550 nm. Isolated mouse brain mitochondria (0.5 mg/ml) in the buffer containing 10 mM Tris-HCI, pH 7.0, 0.5 M sucrose, 0,05 % Triton X- 100 were incubated with 0.1 % DMSO alone, 50 μΜ of clioquinol or 50 μΜ of GMP-1 for 2 h, 4°C. After addition of ferrocytochrome c ratios of decrease in 550 nm absorbance were immediately measured. Experiments were performed in triplicate.

Αβ₄₂ fibril formation kinetics was studied (e.g. in Example 9 below) using thioflavin T (ThT) fluorescence measurement (A_ex = 440 nm, A_em = 490 nm) in a plate reader (FLUOStar Galaxy from BMG Labtech, Offenberg, Germany). The fluorescence was recorded using bottom optics in half-area 96-well polyethylene glycol-coated black polystyrene plates with clear bottom (Corning Glass, 3881). Αβ₄₂ monomer was isolated by size exclusion chromatography over a Superdex 75 column (GE Healthcare) in 20 mM sodium phosphate, 200 μΜ EDTA, 0.02% NaN₃ at pH 8 or 20 mM Tris-HCI pH 7.5 and kept on ice. Every sample was supplemented with 10 μΜ ThT from a 1 mM stock solution. 5 μΜ of Αβ₄2 was incubated with 5 μΜ of CuCI₂ for 4 h at 25°C followed by addition of 0.01 % of DMSO alone, 5 μΜ of clioquinol alone or 5 μΜ of compound. Fluorescence was measured every 5 min during 16 h. Standard deviation of four measurements shown.

The fly lines containing single and double copies of a signal-peptide-Αβ^ transgene were generated as described (Crowther, D. C. et al., Neuroscience, 132, 123-135 (2005)). The fly line expressing in the neurons dimer Αβ₄2 peptide connected via a linker of 12 amino acids was generated as described (Speretta, E. et al., 287, 20748-20754 (2012)).

For fly assays (e.g. in Examples 1 1 and 12 below), flies were maintained on the standard food containing 1 % Agar, 8 % Brewer^'s yeast, 8 % fructose, 5 % potato dry powder, 0.05 % Nipagin, 0.1 % ascorbate. Indicated amounts of compound were added directly to the food during solidification. The fly mobility assay represents the percentage of flies that able to cross the line at 8 cm from the bottom of test tube in 10 seconds. The survival assay in flies expressing dimer Αβ₄2 in the neurons was calculated as percentage of adult flies carrying the transgene, plain wings phenotype, to the total number of hatched flies with plain + curly wings phenotype. Transgenic flies expressing the mutant form of human FUS protein were generated as described by (Lanson, N. A. Jr., et ai, Hum Mol Genet, 20, 2510-2523 (201 1)). Survival analysis of transgenic drosophila flies expressing the mutant form of human FUS protein (e.g. in Example 20 below) was performed in the presence of various amounts of Compound 4, also referred to herein as GMP-1.

Experiments with 5xFAD transgenic mice were performed at QPS CRO facility in Graz, Austria. Four groups of 15 animals were used: tg mice having 0.5 % DMSO in their drinking water ad libitum as placebo; tg mice that received 16.7 mg/kg of compound in the drinking water from 3 weeks of age until the end of experiment at 6 months of age; tg mice that received 16.7 mg/kg of compound in the drinking water at the age of 5.5 weeks during 2 weeks; non-tg littermates receiving 0.5 % DMSO in the drinking water. For the Open Field test (e.g. in Example 13 below), a Plexiglas Open Field (48x48 cm; TSE-System®) was used. The infrared photo beams were placed in a 1.4 cm distance around the box. Each test session lasted for 5 minutes to check the mouse's behaviour in the new surroundings. Testing was performed under standard room lighting conditions during the light phase of the circadian cycle. The Contextual Fear Conditioning test (e.g. in Example 14 below) was conducted in an automated box provided by TSE-Systems, Germany. Mice were trained and tested on 2 consecutive days. On the training day, mice received a foot shock (0.5 mA, 2 s) 5 seconds after being placed into the conditioning chamber. 30 seconds afterwards they were returned to their home cage again. 24 hours after training, mice were tested by being returned to the conditioning chamber for 5 minutes without any shock, and freezing behaviour was recorded by the automated system and evaluated separately every minute. Freezing is defined as lack of movement except that required for respiration and is expressed as freezing time in percent of the testing time.

Histological examination was performed with sagittal cryosections (10 μηι thickness) which have been prepared from fixed frozen hemibrains. The right hemisphere of each mouse was systematically and uniformly sectioned at 12 mediolateral levels (collecting 10 sections per level and discarding the next 20 sections) on a Leica CM 3050S cryotome. Collection of sections started with a random section at approximately 0.2 mm lateral from midline and extended to approximately 3.6 mm lateral (based on the Mouse Brain Atlas). Sections were stored at -20 °C until used in histological stainings. In order to analyze different features of histopathology the following targets were chosen for immunofluorescent labeling and quantitative analysis (e.g. in Examples 15, 17 and 18 below): astroglia (GFAP), activated microglia (CD1 1 b), β-amyloid (6E10). All measurements except region size are threshold based, thus objects above certain intensity and above a certain size are automatically detected by ImageProPlus software (v6.2). The measurements are done within an area of interest (AOI), which is manually delineated for each slice and each brain region. Using this AOI, the size of the specific brain area is determined. Values of five slices per animal deriving from five different medio-sagittal levels were averaged to an individual mean; group values were calculated using the individual means. Data were tested for normality using a Kolmogorov Smirnov test; differences between groups were calculated by one-way ANOVA followed by a Newman Keuls post hoc test, the alpha-error set to 0.05.

Example 1

Compounds as described in the table below were tested using the general experimental procedures described herein above in order to determine:

(i) inhibition of Tom34/C90-HRP interactions;

(ii) toxicity towards SH-SY5Ycells (at 100 μΜ);

(iii) fly toxicity (at 50 μΜ); and

(iv) binding of Cu²7Zn²⁺,

the results of which are presented in Table 1 below. In the event of a discrepancy between the structure shown and the compound name provided, it is intended that the structure should prevail (unless the structure is unclear or clearly incorrect in the context of the invention as described herein). For the avoidance of doubt, example compounds described herein may be named and/or represented as tautomeric forms of compounds of formula I (which compounds may be renamed and/or redrawn in the corresponding tautomeric form as required for compounds of formula I).

Table 1 : Structure and analysis of Compounds 1 to 45

2-(2-methoxyphenyl) 80 μΜ + + pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

2-[(pyridin-2-ylsulfanyl) 80 μΜ +

methyl]pyrimido[1 ,2-a]

benzimidazol-4-ol

2- 75 μΜ +

(trifluoromethyl)pyr

imido[1 ,2- a]benzimidazol- 4(1 H)-one

3-(2-methyl-4-oxopyrimido 85 μΜ +

[1 ,2-a]benzimidazol- 1 (4H)- yl)propanenitrile

1 -benzyl-2,3- 80 μΜ

dimethylpyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

ethyl-4-hydroxypyrimido 90 μΜ +

[1 ,2-a]benzimidazole-3- carboxylate

2-{[(5-methyl-1 ,3,4- >100 μΜ + thiadiazol-2-yl)sulfanyl]

methyl}pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one 2-[(1 ,3-benzothiazol-2- >100 μΜ + + ylthio)methyl]pyrimido[1 ,2- a]benzimidazol-4(1 H)-one

C¾K^3

3-butyl-2-hydroxypyrimido >100 μΜ

[1 ,2-a]benzimidazol-4(1 H)- one

(4-hydroxypyrimido[1 ,2-a] 65 μΜ + benzimidazol-2-yl)acetic

acid

2-[(2-pyridinylthio)methyl] 95 μΜ

pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

2-phenyl-3-propylpyrimido >100 μΜ +

[1 ,2-a]benzimidazol- 4(1 H)- one

1 - ethyl-2- 85 μΜ + methylpyrimido[1 ,

2- a]benzimidazol- 4(1 H)-one

2-methyl-1 -(2-oxopropyl) 80 μΜ + pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

2-(3,4-dimethoxyphenyl) >100 μΜ + + + pyrimido[1 ,2-a]

benzimidazol-4-ol 10-(3-methylbutyl)-2- 90 μΜ

⁵ V_CK. phenylpyrimido[1 ,2-a]

benzimidazol-4(10H)-one

10-butyl-2- 100 μΜ + propylpyrimido[1 ,2-a]

benzimidazol-4(10H)-one

3-benzyl-2- >100 μΜ + methylpyrimido

[1 ,2-a]benzimidazol-4-ol

10-butyl-2-(4- >100 μΜ + chlorophenyl)

pyrimido[1 ,2-a]

benzimidazol-4(10H)-one

2-methyl-3-(3-methylbutyl) 90 μΜ + pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

3-(4-chlorobenzyl)-2- >100 μΜ methylpyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

10-benzyl-2-tert- >100 μΜ butylpyrimido[1 ,2-a]

benzimidazol-4(10H)-one

28 2-(trifluoromethyl)-10- >100 μΜ

(2,4,6-trimethylbenzyl)

pyrimido[1 ,2-a]

benzimidazol-4 (10H)-one

29 2-phenyl-10-(2,4,6- >100 μΜ

trimethylbenzyl)pyrimido[1

2-a]benzimidazol-4(10H)- one

30 2-tert-butyl-10-[3- >100 μΜ

(trifluoromethyl) benzyl]

pyrimido[1 ,2-a]

benzimidazol-4(10 H)-one

31 10-(2,5-dimethylbenzyl)-2- >100 μΜ +

methylpyrimido[1 ,2-a]

benzimidazol-4(10H)-one

32 2-(4-fluorophenyl) 85 μΜ

pyrimido

[1 ,2-a]benzimidazol-4-ol

33 3-(4-oxo-2-phenyl-1 ,4- >100 μΜ

dihydropyrimido[1 ,2-a]

benzimidazol-3-yl)

propanenitrile

34 2-tert-butylpyrimido[1 ,2-a] 75 μΜ + + +

benzimidazol-4-ol

42 3-(3-chlorobenzyl)-2- >100 μΜ +

methylpyrimido[1 ,2-a]

benzimidazol-4-ol

43 10-(4-methylbenzyl)-2- >100 μΜ + +

phenylpyrimido[1 ,2-a]

benzimidazol-4(1 OH)-one

44 et h y I (4- hyd roxy pyri m id o 85 μΜ +

[1 ,2-a]benzimidazol-2-yl)

acetate

45 2-methyl-3-(2-phenylethyl) >100 μΜ

pyrimido[1 ,2-a]

benzimidazol-4(1 H)-one

H

Example 2

A dot-blot assay of interaction between purified human Tom34 protein and 10 amino acid synthetic peptide corresponding to the utmost C-terminus of the human Hsp90 protein coupled to the horse-radish peroxidase (C90-HRP) in accordance with the general experimental procedures described above. The assay was performed in the presence of vehicle (1 % DMSO) or Compound 4, also referred to herein as GMP-1 (100 μΜ). The results are presented in Figure 1A.

Example 3

The concentration-dependent inhibition of Tom34-C90-HRP interactions by Compound 4, also referred to herein as GMP-1 , was measured in accordance with the general experimental procedures described above. The results are presented in Figure 1 B, wherein values are results of 3 independent experiments.

Example 4

A co-immunoprecipitation assay of SH-SY5Y cell lysate treated with DMSO only or with 50 μΜ of Compound 4, also referred to herein as GMP-1 , was performed in accordance with the general experimental procedures described herein above. Capture antibodies were either against human Tom40 protein or pre-immune serum. Developing antibodies (22c11) were against amyloid precursor protein (APP) and against Tom40. The results are shown in Figure 2A, wherein signal quantification from 3 independent experiments is also presented.

Example 5

Figure 2B shows immunostaining results of fractionated SH-SY5Y cells with 22c1 1 antibodies, as performed in accordance with the general experimental procedures described above. Signal quantification in the mitochondrial and light membrane fractions treated either with DMSO only or with Compound 4, also referred to herein as GMP-1 , from three independent experiments is presented.

Example 6

Figure 3A schematically presents the putative copper/zinc binding site on a compound of formula I as described herein.

Figure 3B represents an absorbance scan (λ=220-350 nm) of Compound 4, also referred to herein as GMP-1 , upon addition of increasing amounts of copper (left chart) and zinc (right chart). It was noted that both maximum peaks of absorbance (230 nm and 330 nm) are decreased upon metal addition.

Figure 3C represents pH-dependent binding of Cu²7Zn²⁺ to Compound 4, also referred to herein as GMP-1 , calculated as percentage of light absorbance at 330 nm. It was noted that binding is sharply decreased at pH < 6.5 with 50 % binding at pH 6.3.

Example 7 An SDS-PAGE analysis of β-casein cleavage with collagenase in the absence or presence of various metal chelators was performed in accordance with the general experimental procedures described herein, as follows:

Lane 1 : β-casein alone, lanes 2-5 β-casein cleavage with collagenase;

Lane 2: no chelator addition, lane 3: collagenase preincubated with 50 μΜ EDTA for 10 min, lane 4: collagenase preincubated with 50 μΜ of Compound 4, also referred to herein as GMP-1 , for 10 min, lane 5: collagenase preincubated with 50 μΜ clioquinol for 10 min.

The results are presented in Figure 4A.

Example 8

In accordance with the general experimental proceedures described herein above, cytochrome oxidase activity was measured in isolated mouse brain mitochondria incubated with DMSO only or with 50 μΜ clioquinol and 50 μΜ of Compound 4, also referred to herein as GMP-1.

The results are presented in Figure 4B. Example 9

Figure 4C represents time course of thioflavin T fluorescence measurement of Αβ₄2 (3 μΜ) fibrillization in the presence of Cu2+ alone (5 μΜ) or together with clioquinol (5 μΜ) or Compound 4, also referred to herein as GMP-1 (5 μΜ), as analysed in accordance with the general experimental procedures described herein above.

Example 10

An MTT viability assay of SH-SY5Y cells treated with DMSO only lane 1 , or with Αβ₄₂ (5 μΜ) in the absence (lane 2) or presence of increasing amounts of Compound 4, also referred to herein as GMP-1 , as follows: lane 3: 10 μΜ, lane 4: 30 μΜ, lane 5: 100 μΜ.

Αβ₄2 and Compound 4, also referred to herein as GMP-1 , were added to the culture medium of differentiated SH-SY5Y cells and toxicity was monitored after an incubation period of 48 h using an MTT assay.

The results are presented in Figure 5. Example 1 1

A mobility assay of transgenic drosophila flies expressing Αβ₄2 in nervous cells in the absence or presence of Compound 4, also referred to herein as GMP-1 (100 μΜ, in the food media), was performed in accordance with the general experimental procedures described herein above. The mobility was calculated as percentage of flies that able to cross the line at 8 cm from the bottom of test tube in 10 seconds. Three independent measurements were performed at each point.

The results are presented in Figure 6A. Example 12 Figure 6B represents results of a viability assay using flies expressing in the neurons dimer Αβ₄2 peptide connected via linker of 12 amino acids (see Speretta, E. et al., J Biol Chem., 287, 20748-20754 (2012)), which is more toxic variant of Αβ₄2, in accordance with the general experimental procedures described herein above. These flies exhibit temperature-dependent survival deficit.

The assay was performed in the tubes with DMSO only added to the fly food media or in the tubes with increasing amounts of GMP-1. Results of 4 independent experiments are presented, with P < 0.01 as compared to control tubes at 25 °C. Example 13

An open field test with 6 months old transgenic AD model (5xFAD) mice expressing APP in CNS treated for 5 months with DMSO only or with 16.7 mg/kg of Compound 4, also referred to herein as GMP-1 , in the drinking water, in accordance with the general experimental procedures described herein above. Non-transgenic mice of the same genetic background were used as controls. 15 animals in each group were used in the study.

The results are presented in Figure 7A. Example 14 Figure 7B represents the results of contextual fear conditioning test using 6 months old transgenic mice and control non-transgenic mice, following the general experimental procedures described herein above. Transgenic mice were treated with DMSO only or with 16.7 mg/kg of Compound 4, also referred to herein as GMP-1 , in the drinking water for 5 months or for 2 weeks prior the test. 15 animals in each group were used in the study.

Example 15 Figure 8A represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed to Αβ₄2 (6E10), in accordance with the general experimental procedures described herein above, as follows:

Graph A represents the Αβ plaque area of tg animals treated with Compound 4, also referred to herein as GMP-1 , for 2 weeks prior the test;

Graph B represents the Αβ plaque area of tg animals treated with DMSO only;

Graph C represents the Αβ plaque area of tg animals treated with Compound 4, also referred to herein as GMP-1 , for 5 month prior the test;

Graph D represents the Αβ plaque area of non-tg animals. Four animals in each group were analysed.

Example 16

Figure 8B provides the results of a western blot analysis of total brain extract or purified mitochondria with 6E10 antibody, in accordance with the general experimental procedures described herein. Tg mice were treated either with DMSO only or with Compound 4, also referred to herein as GMP-1 , for 5 months prior to analysis. Six animals in each group were used. Example 17

Figure 9A represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed GFAP protein, a marker for astrocytosis, in accordance with the general experimental procedures described herein above, as follows: Graph A represents the Αβ plaque area of tg animals treated with Compound 4, also referred to herein as GMP-1 , for 2 weeks prior the test;

Graph B represents the Αβ plaque area of tg animals treated with DMSO only; Graph C represents the Αβ plaque area of tg animals treated with Compound 4, also referred to herein as GMP-1 , for 5 months prior the test;

Example 18

Figure 9B represents immunohistochemical results of brain cortex and hippocampus sections stained with antibodies directed CD11 b protein, a marker for microglia activation, in accordance with the general experimental procedures described herein, as follows:

Graph B represents the Αβ plaque area of tg animals treated with DMSO only;

Graph C represents the Αβ plaque area of tg animals treated with Compound 4, also referred to herein as GMP-1 , for 5 months prior to the test;

Graph D represents the Αβ plaque area of non-tg animals.

Four animals in each group were analysed.

Example 19

In accordance with the general experimental procedures described herein, an analysis of cytochrome oxidase activity in purified brain mitochondria from non-tg mice and 5XFAD mice was performed: 5xFAD mice treated with DMSO only or 5xFAD mice treated with 16.7 mg/kg of Compound 4, also referred to herein as GMP-1 , in the drinking water for 5 months. Six animals in each group were analysed.

The results are presented in Figure 10.

Example 20

In accordance with the general experimental procedures described herein, the survival of transgenic drosophila flies expressing the mutant form of human FUS protein (see Lanson, N. A. Jr, et ai, Hum Mol Genet, 20, 2510-2523 (201 1)), was analysed in relation to varying concentrations of Compound 4, also referred to herein as GMP-1. The results are presented in Figure 11.

Claims

1. A compound of formula I

or a tautomer and/or pharmaceutically acceptable salt thereof, for use in the treatment or prevention of a neurodegenerative disorder, wherein: either X represents NR³ and the dashed bond by which it is bound represents a single bond, and Y represents N and the dashed bond by which it is bound represents a double bond, or X represents N and the dashed bond by which it is bound represents a double bond, and Y represents NR⁴ and the dashed bond by which it is bound represents a single bond;

R¹ represents H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -NR^a3R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a1\ Ci-e alkyl optionally substituted with one or more R^a12, aryl optionally substituted with one or more G¹ or heteroaryl optionally substituted with one or more G²,

R² represents H, halo, -CN, -N0₂, -OR^a1 , -S(0)_PR^a2, -NR^a3R^a4, -S(0)_qN(R^a5)R^a6, -C(0)N(R^a7)R^a8, -OC(0)N(R^a9)R^a1°, -C(0)OR^a11 , Ci-e alkyl optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G¹ , or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, aryl optionally substituted by one or more G³, heteroaryl substituted by one or more G⁴, or a 5- to 6-membered alkyl ring, which ring optionally contains one or two heteroatoms and which ring is optionally substituted by one or more E¹ ; where present, R³ represents H, halo, -CN, -N0₂, -OR^b1 , -S(0)_PR^b2, -NR^b3R^b4, -S(0)_qN(R^b5)R^b6, -C(0)N(R^b7)R^b8, -OC(0)N(R^b9)R^b1°, -C(0)OR^b1\ Ci-e alkyl optionally substituted with one or more R^b12, aryl optionally substituted with one or more G⁵ or heteroaryl optionally substituted with one or more G⁶; where present, R⁴ represents H, halo, -CN, -N0₂, -OR^c1 , -S(0)_PR^c2, -NR^R⁰⁴, -S(0)_qN(R^c5)R^c6, -C(0)N(R^c7)R^c8, -OC(0)N(R^c9)R^c1°, -C(0)OR^c11 , Ci-₆ alkyl optionally substituted with one or more R^c12, aryl optionally substituted with one or more G⁷ or heteroaryl optionally substituted with one or more G⁸; each Z independently represents halo, -CN, -N0₂, -OR^d1 , -S(0)_PR^d2, -NR^d3R^d4, -S(0)_qN(R^d5)R^d6, -C(0)N(R^d7)R^d8, -OC(0)N(R^d9)R^d1°, -C(0)OR^d11 , Ci-e alkyl optionally substituted with one or more R^d12, aryl optionally substituted with one or more G⁹ or heteroaryl optionally substituted with one or more G¹⁰; each R^a1 to R^a1\ R^b1 to R^b1\ R^c1 to R^c11 and R^d1 to R^d11 independently represent H, Ci-₆ alkyl optionally substituted with one or more E², aryl optionally substituted with one or more G¹¹ or heteroaryl optionally substituted with one or more G¹²; or alternatively each of R^a3 and R^a4, R^a5 and R^a6, R^a7 and R^a8, R^a9 and R^a1°, R^b3 and R^b4, R^b5 and R^b6, R^b7 and R^b8, R^b9 and R^b1°, R and R⁰⁴, R^c5 and R^c6, R^c7 and R^c8, R^c9 and R^c1°, R^d3 and R^d4, R^d5 and R^d6, R^d7 and R^d8, and R^d9 and R^d1° may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E³; each R^a12, R^b12, R^c12 and R^d12 independently represents oxy, halo, -CN, -N0₂, -OR^e1 , -SR^e2, -NR^e2R^e3, -C(0)OR^e5, aryl optionally substituted with one or more G¹³ or heteroaryl optionally substituted with one or more G¹⁴; each R^e1 to R^e5 independently represent Ci-e alkyl optionally substituted with one or more E⁴, aryl optionally substituted with one or more G¹⁵ or heteroaryl optionally substituted with one or more G¹⁶; or alternatively R^e3 and R^e4 may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E⁵; each G¹ to G¹⁶ independently represents oxy, halo, -CN, -N0₂, -OR^f1 , -SR^f2, -NR^f3R^M, -C(0)OR^f5, C1-6 alkyl optionally substituted with one or more E⁶; each R^f1 to R^f5 independently represent H or Ci-e alkyl optionally substituted with one or more E⁷, or alternatively R^f3 and R^M may be linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered alkyl ring, which ring optionally contains one further heteroatom and which ring is optionally substituted by one or more E⁸; each E¹ to E⁸ independently represents oxy, halo, -CN, -N0₂, -OR⁹¹ , -SR⁹², -NR⁹²R⁹³ or -C(0)OR⁹⁵; each R⁹¹ to R⁹⁵ independently represents H or C1-3 alkyl optionally substituted with one or more fluoro; n represents 0 to 4; and p represents 0, 1 or 2.

2. The compound for use of Claim 1 , wherein:

R¹ and R² each independently represent H, halo, -OR^a1 , -C(0)OR^a11 , C1-6 alkyl optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G¹ , or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl (i.e. a phenyl ring) optionally substituted by one or more G³.

3. The compound for use of Claim 1 or Claim 2, wherein:

R¹ and R² each independently represent H, halo, -OR^a1 , -C(0)OR^a1\ C1-6 alkyl (e.g. C1.5 alkyl) optionally substituted with one or more R^a12 or aryl optionally substituted with one or more G\ or alternatively R¹ and R² may be linked together to form, together with the carbon atoms to which they are attached, a 6-membered aryl.

4. The compound for use of any one of Claims 1 to 3, wherein R^a12 represents oxy, halo, -CN, -OR^e1 , -SR^e2, -C(0)OR^e5 or aryl optionally substituted with one or more G¹³.

5. The compound for use of any one of Claims 1 to 4, wherein:

R^a12 represents oxy, halo, -CN, -OR^e1 , -SR^e2, -C(0)OR^e11 or phenyl optionally substituted with one or more G¹³; R^e1 represents C1-3 alkyl optionally substituted with one or more fluoro;

R^e2 represents phenyl optionally substituted with one or more halo or C1-3 alkyl (e.g. methyl) group, or heteroaryl optionally substituted with one or more halo or C1-3 alkyl group; R^e5 represents H or C1-3 alkyl; and/or

G¹³ represents a halo or -OCi-3 alkyl group.

6. The compound for use of any one of Claims 1 to 5, wherein:

R¹ and R² each independently represent H or C1-6 alkyl optionally substituted with one or more R^a12;

R^a12 represents halo or -OR^e1 ; and

R^e1 represents C1-3 alkyl optionally substituted with one or more fluoro.

7. The compound for use of any one of Claims 1 to 6, wherein: R¹ represents H; and/or

R² represents H, methyl or -CH2OCH3.

8. The compound for use of any one of Claims 1 to 7, wherein R² represents

9. The compound for use of any one of Claims 1 to 8, wherein the compound of formula I is represented by a compound of formula la

(la) wherein R¹ to R³, Z and n are as claimed in any one of Claims 1 to 9.

10. The compound for use of Claim 9, wherein R³ represents H or Ci-e alkyl optionally substituted with one or more R^b12.

1 1. The compound for use of Claim 9 or Claim 10, wherein:

R³ represents H or Ci-e alkyl optionally substituted with one or more R^b12; and R^b12 represents oxy, halo (e.g. fluoro), -CN or phenyl optionally substituted by one or more halo (e.g fluoro).

12. The compound for use of any one of Claims 9 to 11 , wherein: R³ represents H or C1-3 alkyl optionally substituted with one or more R^b12; and R^b12 represents oxy, -CN or phenyl.

13. The compound for use of any one of Claims 9 to 12, wherein R³ represents H.

14. The compound for use of any one of Claims 1 to 8, wherein the compound of formula I is represented by a compound of formula lb

wherein R¹ , R², R⁴, Z and n are as claimed in any one of Claims 1 to 8.

15. The compound for use of Claim 15, wherein R⁴ represents Ci-e alkyl optionally substituted with one or more R^c12.

16. The compound for use of any one of Claims 14 and 15, wherein:

R⁴ represents Ci-e alkyl optionally substituted with one or more R^c12; and

R^c12 represents phenyl optionally substituted with one or more halo or C1-3 alkyl optionally substituted with one or more halo.

17. The compound for use of any one of Claims 1 to 16, wherein:

Z represents halo (e.g. fluoro) or C1-3 alkyl (e.g. methyl) optionally substituted with one or more halo (e.g. fluoro); and/or n represents 0 or 1.

18. The compound for use of any one of Claims 1 to 17, wherein:

Z represents fluoro; and/or n represents 0 or 1.

19. The compound for use of any one of Claims 1 to 18, wherein n represents 0.

20. The compound for use of any preceding claim, wherein the treatment is in a human.

21. The compound for use of any preceding claim, wherein the neurodegenerative disorder is Alzheimer's disease, Parkinson's disease or amyotrophic lateral sclerosis.

22. The compound for use of any preceding claim, wherein the neurodegenerative disorder is Alzheimer's disease.

23. A pharmaceutical composition comprising a compound as defined in any one of Claim 1 to 19, and optionally one or more pharmaceutically acceptable adjuvant, diluent and/or carrier, for use in the treatment or prevention of a neurodegenerative disorder as defined in any one of Claims 1 to 22.

24. A pharmaceutical composition comprising a compound as defined in any one of Claim 1 to 19, and optionally one or more pharmaceutically acceptable adjuvant, diluent and/or carrier, and an additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder as defined in any one of Claims 1 to 22.

25. A combination product comprising:

(A) a compound as defined in any one of Claims 1 to 19; and

(B) one or more additional therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder as defined in any one of Claims 1 to 22,

wherein each of components (A) and (B) is formulated in admixture, optionally with one or more a pharmaceutically-acceptable adjuvant, diluent or carrier.

26. A kit-of-parts comprising:

(a) a compound as defined in any one of Claims 1 to 19, or a pharmaceutical composition as defined in Claim 23; and

(b) one or more other therapeutic agent suitable for the treatment or prevention of a neurodegenerative disorder as defined in any one of Claims 1 to 22, optionally in admixture with one or more pharmaceutically-acceptable adjuvant, diluent or carrier,

27. A compound, compound for use, use, method, formulation, formulation for use, product or kit substantially as described herein, with reference to the examples.