Patent Publication Number: US-2023144901-A1

Title: Sortilin antagonists for use in the treatment of diabetic retinopathy

Description:
FIELD OF THE INVENTION 
     The present invention relates to the use of sortilin antagonists, in particular compounds of Formula (I) and preferably Formula (II), in the treatment or prevention of diabetic retinopathy. 
     BACKGROUND 
     Diabetic retinopathy is a complication of diabetes mellitus (DM) that can cause vision loss and blindness as a result of damage to the retina of the eye. The pathogenesis of diabetic retinopathy is thought to involve capillary occlusion and ischaemia in the retinal periphery and hyperperfusion and hyperpermeability in the macular area. 1  Current treatments of diabetic retinopathy include blocking vascular endothelial growth factor (VEGF) signalling, which is an important mediator for these changes, laser photocoagulation (focal or panretinal) or vitrectomy. However, these treatments only treat symptoms and not the underlying disease. 2    
     Sortilin (encoded by SORT1) is a type 1 membrane receptor in the vacuolar protein sorting 10 protein (VPS10P) family of sorting receptors, and is most abundantly expressed in the central nervous system. Sortilin has an amino acid sequence according to SEQ ID NO: 1 and comprises a signal peptide, a propeptide, the Vps10p domain, a 10 cc domain (10CCa+10CCb), a transmembrane domain and a large cytoplasmic tail. The luminal domain of sortilin has 6 potential N-linked glycosylation sites, whilst the cytoplasmic tail enables for the recruitment of various adapter proteins. 
     Sortilin binds to a vast number of ligands and membrane receptors and as a result engages in functions known to be important in cellular signalling and sorting. For example, sortilin is involved in signalling by proneurotrophins: the proforms of nerve growth factor (proNGF), brain derived neurotrophic factor (proBDNF), and neurotrophin-3 (proNT3), respectively. In complex with the protein p75NTR, sortilin has been reported to form the receptor for pro-neurotrophin-mediated apoptotic effects leading to degeneration and cell death in cellular and animal models 3,4,5 . However, sortilin has not been implicated in disease processes of the retina induced by diabetes. 
     There is an unmet need for new substances useful in the treatment, e.g. by means of delaying progression of symptoms, and prevention of diabetic retinopathy, which address the underlying causes of the disease and not just the symptoms. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG.  1    depicts the reduction in the “a wave” component of the fERG response 8 weeks after induction of diabetes compared to the baseline, in a diabetic mouse model study using a polyclonal anti-sortilin antibody. 
         FIG.  2    depicts the reduction in the “b wave” component of the fERG response 8 weeks after induction of diabetes compared to the baseline, in a diabetic mouse model study using a polyclonal anti-sortilin antibody. 
         FIG.  3    depicts the reduction in the “a wave” component of the fERG response 8 weeks after induction of diabetes compared to the baseline, in a diabetic mouse model study using Example 8 of the application. 
         FIG.  4    depicts the reduction in the “b wave” component of the fERG response 8 weeks after induction of diabetes compared to the baseline, in a diabetic mouse model study using Example 8 of the application. 
     
    
    
     DISCLOSURE OF THE INVENTION 
     The present invention is based on the surprising discovery that sortilin is implicated in diabetic retinopathy. Without wishing to be bound by theory, it is thought that the protein sortilin is upregulated in the eye in diabetic patients, in particular in the Müller cells. Sortilin can form a trimeric complex with the low-affinity nerve growth factor receptor (p75NTR) and a pro-neurotrophin, such as proNGF, proBDNF or proNT3, resulting in cell death of retinal and ganglion cells while at the same time preventing the conversion of the proform into its mature and trophic form. The present invention provides substances which interfere with the binding of sortilin to pro-neurotrophins, which: 1) prevents the trimeric apoptotic complex of sortilin, p75NTR and the pro-neurotrophin from forming, and 2) prevents sortilin mediated clearance of the pro-neurotrophins, providing a pool of substrate to be converted into the mature and trophic neurotrophin. Thus, sortilin-proneurotrophin interference can be used in protecting the eye from damage resulting from the aforementioned cell death. 
     It has surprisingly been found that sortilin antagonists, in particular compounds of Formula (I) and (II), may be useful in the treatment or prevention of diabetic retinopathy. 
     According to a first aspect of the invention, there is provided a sortilin antagonist for use in the prevention or treatment of diabetic retinopathy, wherein the sortilin antagonist is a compound of Formula (I): 
     
       
         
         
             
             
         
       
     
     or a pharmaceutically acceptable salt, solvate, hydrate, geometrical isomer, tautomer, optical isomer, N-oxide, and/or prodrug thereof, wherein
 
Y is selected from the group consisting of —O—, —NR 5 —, and —S—;
 
Z is selected from the group consisting of optionally substituted C 1 -C 6  alkyl, optionally substituted C 5 -C 10  aryl, and optionally substituted C 1 -C 9  heteroaryl, wherein C 6 -C 10  aryl and C 1 -C 9  heteroaryl are optionally substituted with one or more substituents independently selected from the group consisting of —OR 15 , halo, and C 1 -C 4  alkyl, wherein R 15  is H, C 1 -C 3  alkyl, or C 4  alkyl,
         and/or wherein an alkylene group is attached to two adjacent atoms of the C 6 -C 10  aryl or C 1 -C 9  heteroaryl group to form a 5- or 6-membered partially saturated or saturated ring, optionally wherein the alkylene group is substituted with one or more halo atoms;
 
A, B, C and D are each independently selected from the group consisting of H, optionally substituted C 1 -C 6  alkyl, halo, NO 2 , optionally substituted C 6 -C 10  aryl, optionally substituted C 1 -C 9  heteroaryl, —OR 6 , NR 7 R 8 , —SR 9 , —C(O)OR 10 , —C(O)NR 11 R 12 , —C(O)SR 13 , C(O 2 )SR 14 ;
 
R 1 , R 4 , R 5 , R 6 , R 9 , R 10 , R 13 , and R 14  are each independently selected from the group consisting of H and C 1 -C 6  alkyl group, wherein the C 1 -C 6  alkyl is optionally substituted with one or more halo atoms; and
 
R 2 , R 3 , R 7 , R 8 , R 11 , and R 12  are each independently selected from the group consisting of H and C 1 -C 6  alkyl, wherein the C 1 -C 6  alkyl is optionally substituted with one or more halo atoms, or R 2  and R 3 , R 7  and R 8 , and/or R 11  and R 12  can be taken together with the nitrogen atom to which they are attached to from a 5- or 6-membered heterocycle, optionally substituted with one or more halo atoms.
       

     According to another aspect of the invention, there is provided a use of a sortilin antagonist in the manufacture of a medicament for the prevention or treatment of diabetic retinopathy, wherein the sortilin antagonist is a compound of Formula (I) as defined above. 
     According to another aspect of the invention, there is provided a method of preventing or treating diabetic retinopathy by administering a therapeutically effective amount of a sortilin antagonist to a subject in need thereof, wherein the sortilin antagonist is a compound of Formula (I) as defined above. 
     The invention also provides a pharmaceutical formulation comprising the sortilin antagonist of the invention, in particular ophthalmic pharmaceutical formulations. 
     As used herein, the term “sortilin” may refer to full length sortilin (also referred to as immature sortilin), comprising a signal peptide, a propeptide, a Vps10p domain, a 1000 domain, a transmembrane domain and a large cytoplasmic tail, having an amino acid sequence according to SEQ ID NO: 1 or SEQ ID NO: 2, or it may refer to mature sortilin, comprising a Vps10p domain, a 1000 domain, a transmembrane domain and a large cytoplasmic tail, having an amino acid sequence according to SEQ ID NO: 3, or a naturally occurring fragment, homologue or variant thereof. The term “sortilin” or “sortilin molecule” (used interchangeably herein) as used herein may also include any protein that is functionally related to sortilin, i.e a sortilin-related molecule, for example, SorCS2. Therefore, for the avoidance of doubt, any reference to the term “sortilin” in a use, method or composition of the invention, may not only refer to sortilin as defined above but may also be taken to optionally alternatively refer to a functionally related protein, such as SorCS2. It is understood that the sortilin is capable of interacting with a pro-neurotrophin molecule to form a sortilin/pro-neurotrophin complex. This sortilin/pro-neurotrophin complex may or may not be capable of interacting with a p75NTR molecule to form a trimeric complex comprising sortilin, pro-neurotrophin and p75NTR. It is understood that this trimeric complex may be responsible for adverse biological responses, such as stimulating apoptosis in retinal and ganglion cells. 
     As used herein, the term “pro-neurotrophin” refers to the larger precursors of neurotrophins, which undergo proteolytic cleavage to yield the mature form of the neurotrophin. Neurotrophins are a family of proteins that induce the survival, development and function of neurons, and are commonly referred to as growth factors. Pro-neurotrophins are biologically active and have distinct roles compared to their neurotrophin counterparts, such as induction of apoptosis. Examples of pro-neurotrophins include proNGF, proBDNF, proNT3, proNT4, preferably the pro-neurotrophin is proNGF, proBDNF or proNT3, even more preferably the pro-neurotrophin is proNGF. 
     As used herein, the term “sortilin antagonist” refers to a substance (such as an antibody, protein, or other molecule) that interferes with, blocks, or otherwise attenuates the effect of, a sortilin protein binding to a pro-neurotrophin (e.g proNGF, proNT3, proBDNF) and preventing the formation of the trimeric complex between sortilin, p75NTR and the pro-neurotrophin. The term “sortilin antagonist” also includes a substance or agent that interferes with the formation of a high affinity trimeric complex. In the latter scenario, it is recognised that a trimeric complex may be formed in that sortilin can bind to p75NTR (but not proNGF) and p75NTR can simultaneously bind the NGF domain of proNGF. However, the resulting trimeric complex may be of lower affinity for its receptor and as a result have significantly reduced capacity to stimulate apoptosis via the mechanism describe above. The term “sortilin antagonist” also includes a substance or agent that interferes with, blocks, or otherwise attenuates the effect of, a sortilin protein interacting with p75NTR. This interaction may be completely prevented, in which case the trimeric complex is prevented from forming, or only partially prevented, in which case the trimeric complex may be formed but may have reduced biological potency. 
     Thus, in an embodiment, the sortilin antagonist for use according to the invention may disrupt interaction between a sortilin molecule and a pro-neurotrophin molecule, or disrupt the interaction between a sortilin molecule and a p75NTR molecule. 
     Preferably, the sortilin antagonist is a sortilin inhibitor. As used herein, the term “sortilin inhibitor” refers to a substance that binds to a sortilin protein, thereby preventing it from binding to a pro-neurotrophin and preventing the formation of the aforementioned trimeric complex, or resulting in the formation of a trimeric complex that is less active or inactive. The term “sortilin inhibitor” may also refer to a soluble fragment of sortilin, or sortilin-related molecule, which can bind competitively to biologically available pro-neurotrophins but prevent formation of an effective trimeric complex. As a result, the sortilin inhibitor results in an inhibition of receptor activation, which would otherwise occur as a result of ligand binding and/or allows for a shift in unbound/biologically available pro-neurotrophin, which in turn can act through a secondary route/receptor either in its pro- or mature form, specifically, but not limited to Trk family receptors. 
     Preferably, the sortilin antagonist of the present invention prevents the protein-protein interaction between a sortilin protein and a pro-neurotrophin, further preventing the formation of the apoptotic trimeric complex usually formed between sortilin, pro-neurotrophin and the p75NTR receptor, or resulting in the formation of a low affinity trimeric complex, which is biologically less active or inactive or has minimal activity. 
     It is highly preferred that the sortilin antagonist is a “small molecule”. In which case, the sortilin antagonist has a molecular weight of &lt;2000 Da, preferably the sortilin antagonist has a molecular weight of &lt;1000 Da. 
     Compounds of Formula (I) act as sortilin antagonists by binding to sortilin. They are therefore useful in the treatment or prevention of diabetic retinopathy. 
     It is highly preferred that Y is —NR 5 —, more preferably Y is —NH—. In a particularly preferred aspect of the invention, the compound of Formula (I) is a compound of Formula (II): 
     
       
         
         
             
             
         
       
     
     Preferred compounds of Formula (I) and (II), as detailed below, may exhibit increased binding affinity to sortilin and therefore increased efficacy in the treatment or prevention of diabetic retinopathy. 
     In a preferred aspect of the invention, A and D are H. 
     In another preferred aspect of the invention, B and C are independently selected from the group consisting of H, halo, CF 3 , NO 2 , C 1 -C 3  alkyl, and C 4  alkyl. 
     It is more preferred that C is H. 
     It is also more preferred that B is selected from the group consisting of halo and CF 3 , more preferably B is Br or CF 3 . 
     In another preferred aspect of the invention, Z is an optionally substituted C 5 -C 10  aryl or an optionally substituted C 1 -C 9  heteroaryl. 
     It is preferred that the optionally substituted C 6 -C 10  aryl is an optionally substituted phenyl. 
     Particularly preferred optionally substituted C 1 -C 9  heteroaryl groups are optionally substituted 5- or 6-membered heteroaryl groups in which 1 to 5 of the ring atoms are carbon and one or more of the ring atoms are a heteroatom, more preferably optionally substituted 6-membered heteroaryl groups in which 1 to 5 of the ring atoms are carbon and one or more of the ring atoms are a heteroatom. 
     It is preferred that the ring atoms of the optionally substituted 6-membered heteroaryl groups are selected from the group consisting of carbon and nitrogen. 
     In which case, particularly preferred examples of optionally substituted C 1 -C 9  heteroaryl groups are optionally substituted pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, and triazinyl. More preferred optionally substituted C 1 -C 9  heteroaryl groups are optionally substituted pyridyl and pyrimidinyl. 
     Therefore, in a particularly preferred aspect of the invention, Z is an optionally substituted phenyl, an optionally substituted pyridyl, or an optionally substituted pyrimidinyl. 
     Preferably, C 5 -C 10  aryl and C 1 -C 9  heteroaryl of group Z are optionally substituted with one or more substituents selected from the group consisting of Cl, —OMe, and Me. 
     In addition to the above-mentioned preferred optional substituents, an alkylene group may be attached to two adjacent atoms of the C 6 -C 10  aryl or C 1 -C 9  heteroaryl group to form a 5- or 6-membered partially saturated or saturated ring, optionally wherein the alkylene group is substituted with one or more halo atoms. Examples of such fused bicyclic ring systems are shown below in the following two examples of group Z: 
     
       
         
         
             
             
         
       
     
     Particular combinations of Z and its substituents may be particularly preferred, as detailed below. 
     In a particularly preferred aspect of the invention, Z is C 6 -C 10  aryl or C 1 -C 9  heteroaryl. Each of C 5 -C 10  aryl and C 1 -C 9  heteroaryl are independently substituted with one or more substituents independently selected from the group consisting of —OR 15 , halo, and C 1 -C 4  alkyl, wherein R 15  is H or C 1 -C 3  alkyl, preferably one or more substituents independently selected from the group consisting of Cl, —OMe, and Me, and/or an alkylene group is attached to two adjacent atoms of group Z to form a 5- or 6-membered partially saturated or saturated ring, optionally wherein the alkylene group is substituted with one or more halo atoms. 
     In an even more preferred aspect of the invention, Z is phenyl, pyridyl, or pyrimidinyl. Each of phenyl, pyridyl, and pyrimidinyl are independently substituted with one or more substituents independently selected from the group consisting of —OR 15 , halo, and C 1 -C 4  alkyl, wherein R 15  is H or C 1 -C 3  alkyl, preferably one or more substituents independently selected from the group consisting of Cl, —OMe, and Me; and/or an alkylene group is attached to two adjacent atoms of group Z to form a 5- or 6-membered partially saturated or saturated ring, optionally wherein the alkylene group is substituted with one or more halo atoms. 
     Particular compounds for use according to the invention are:
         2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-methyl-6-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(propan-2-yl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-nitrobenzoic acid;   4-[(6-methylpyridin-2-yl)carbamoyl]-[1,1′-biphenyl]-3-carboxylic acid;   4-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-4-(trifluoromethyl)benzoic acid;   4,5-dichloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4,5-dimethyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   3-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(butan-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(propan-2-yl)carbamoyl]benzoic acid;   5-bromo-2-(phenylcarbamoyl)benzoic acid;   5-bromo-2-[(3-methylphenyl)carbamoyl]benzoic acid;   5-bromo-2-[(pyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-chloropyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(4-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(3-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-methylpyridin-3-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyridin-4-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyrimidin-4-yl)carbamoyl]benzoic acid;   2-[(6-methoxypyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6-dimethylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6,7,8-tetrahydroquinolin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid,
 
or a pharmaceutically acceptable salt, solvate, hydrate, tautomer, optical isomer, N-oxide, and/or prodrug thereof.
       

     Particularly preferred compounds for use according to the invention are:
         5-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(propan-2-yl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-nitrobenzoic acid;   4-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-4-(trifluoromethyl)benzoic acid;   4,5-dichloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4,5-dimethyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(3-methylphenyl)carbamoyl]benzoic acid;   5-bromo-2-[(pyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-chloropyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(4-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyridin-4-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyrimidin-4-yl)carbamoyl]benzoic acid;   2-[(6-methoxypyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6-dimethylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6,7,8-tetrahydroquinolin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;
 
or a pharmaceutically acceptable salt, solvate, hydrate, tautomer, optical isomer, N-oxide, and/or prodrug thereof.
       

     According to another aspect of the invention, there is provided a pharmaceutical formulation comprising a sortilin antagonist according to the invention and one or more pharmaceutically acceptable carriers or excipients, for use in the treatment or prevention of diabetic retinopathy. 
     In a preferred aspect of the invention, the pharmaceutical formulation is an ophthalmic formulation. 
     The compounds for use according to the invention may include isotopically-labelled and/or isotopically-enriched forms of the compounds. The compounds for use according to the invention herein may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. Examples of isotopes that can be incorporated into the disclosed compounds include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, chlorine, such as  2 H,  3 H,  11 C,  13 C,  14 C,  13 N,  15 O,  17 O,  32 P,  35 S,  18 F,  36 Cl. 
     The compounds for use according to the invention may be used as such or, where appropriate, as pharmacologically acceptable salts (acid or base addition salts) thereof. The pharmacologically acceptable addition salts mentioned below are meant to comprise the therapeutically active non-toxic acid and base addition salt forms that the compounds are able to form. Compounds that have basic properties can be converted to their pharmaceutically acceptable acid addition salts by treating the base form with an appropriate acid. Exemplary acids include inorganic acids, such as hydrogen chloride, hydrogen bromide, hydrogen iodide, sulphuric acid, phosphoric acid; and organic acids such as formic acid, acetic acid, propanoic acid, hydroxyacetic acid, lactic acid, pyruvic acid, glycolic acid, maleic acid, malonic acid, oxalic acid, benzenesulphonic acid, toluenesulphonic acid, methanesulphonic acid, trifluoroacetic acid, fumaric acid, succinic acid, malic acid, tartaric acid, citric acid, salicylic acid, p-aminosalicylic acid, pamoic acid, benzoic acid, ascorbic acid and the like. Exemplary base addition salt forms are the sodium, potassium, calcium salts, and salts with pharmaceutically acceptable amines such as, for example, ammonia, alkylamines, benzathine, and amino acids, such as, e.g. arginine and lysine. The term addition salt as used herein also comprises solvates which the compounds and salts thereof are able to form, such as, for example, hydrates, alcoholates and the like. 
     Throughout the present disclosure, a given chemical formula or name shall also encompass all pharmaceutically acceptable salts, solvates, hydrates, geometrical isomers, tautomers, optical isomers, N-oxides, and/or prodrug forms thereof. It is to be understood that the compounds for use according to the invention include any and all hydrates and/or solvates of the compound formulas. It is appreciated that certain functional groups, such as the hydroxy, amino, and like groups form complexes and/or coordination compounds with water and/or various solvents, in the various physical forms of the compounds. Accordingly, the above formulas are to be understood to include and represent those various hydrates and/or solvates. 
     Compounds for use according to the invention also include tautomeric forms. Tautomeric forms result from the swapping of a single bond with an adjacent double bond together with the concomitant migration of a proton. Tautomeric forms include prototropic tautomers which are isomeric protonation states having the same empirical formula and total charge. Example prototropic tautomers include ketone-enol pairs, amide-imidic acid pairs, lactam-lactim pairs, amide-imidic acid pairs, enamine-imine pairs, and annular forms where a proton can occupy two or more positions of a heterocyclic system, for example, 1H- and 3H-imidazole, 1H, 2H- and 4H-1,2,4-triazole, 1H- and 2H-isoindole, and 1H- and 2H-pyrazole. Tautomeric forms can be in equilibrium or sterically locked into one form by appropriate substitution. 
     The compounds described herein can be asymmetric (e.g. having one or more stereocenters). All stereoisomers, such as enantiomers and diastereomers, are intended unless otherwise indicated. Compounds for use according to the present invention that contain asymmetrically substituted carbon atoms can be isolated in optically active or racemic forms. Methods on how to prepare optically active forms from optically active starting materials are known in the art, such as by resolution of racemic mixtures or by stereoselective synthesis. Many geometric isomers of olefins, C═N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. Cis- and trans-geometric isomers of the compounds for use according to the present invention are described and may be isolated as a mixture of isomers or as separated isomeric forms. 
     In the case of the compounds, which contain an asymmetric carbon atom, the invention relates to the D form, the L form, and D, L mixtures and also, where more than one asymmetric carbon atom is present, to the diastereomeric forms. Those compounds for use according to the invention which contain asymmetric carbon atoms, and which as a rule accrue as racemates, can be separated into the optically active isomers in a known manner, for example using an optically active acid. However, it is also possible to use an optically active starting substance from the outset, with a corresponding optically active or diastereomeric compound then being obtained as the end product. 
     The term “prodrugs” refers to compounds that may be converted under physiological conditions or by solvolysis to a biologically active compound for use according to the invention. A prodrug may be inactive when administered to a subject in need thereof, but is converted in vivo to an active compound of the invention. Prodrugs are typically rapidly transformed in vivo to yield the parent compound of the invention, e.g. by hydrolysis in the blood. The prodrug compound usually offers advantages of solubility, tissue compatibility or delayed release in a mammalian organism (see Silverman, R. B., The Organic Chemistry of Drug Design and Drug Action, 2nd Ed., Elsevier Academic Press (2004), page 498 to 549). Prodrugs of a compound for use according to the invention may be prepared by modifying functional groups, such as a hydroxy, amino or mercapto groups, present in a compound for use according to the invention in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound for use according to the invention. Examples of prodrugs include, but are not limited to, acetate, formate and succinate derivatives of hydroxy functional groups or phenyl carbamate derivatives of amino functional groups. 
     The term “treatment” as used herein may include prophylaxis of the named disorder or condition, or amelioration or elimination of the disorder once it has been established. The term “prevention” refers to prophylaxis of the named disorder or condition. 
     Methods delineated herein include those wherein the subject is identified as in need of a particular stated treatment. Identifying a subject in need of such treatment can be in the judgment of a subject or a health care professional and can be subjective (e.g. opinion) or objective (e.g. measurable by a test or diagnostic method). 
     In other aspects, the methods herein include those further comprising monitoring subject response to the treatment administrations. Such monitoring may include periodic imaging or sampling of subject tissue, fluids, specimens, cells, proteins, chemical markers, genetic materials, etc. as markers or indicators of the treatment regimen. In other methods, the subject is pre-screened or identified as in need of such treatment by assessment for a relevant marker or indicator of suitability for such treatment. 
     The invention provides a method of monitoring treatment progress. The method includes the step of determining a level of diagnostic marker (Marker) (e.g. any target or cell type delineated herein modulated by a compound herein) or diagnostic measurement (e.g., screen, assay) in a subject suffering from or susceptible to a disorder or symptoms thereof delineated herein, in which the subject has been administered a therapeutic amount of a compound herein sufficient to treat the disease or symptoms thereof. The level of Marker determined in the method can be compared to known levels of Marker in either healthy normal controls or in other afflicted patients to establish the subject&#39;s disease status. In preferred embodiments, a second level of Marker in the subject is determined at a time point later than the determination of the first level, and the two levels are compared to monitor the course of disease or the efficacy of the therapy. In certain preferred embodiments, a pre-treatment level of Marker in the subject is determined prior to beginning treatment according to this invention; this pre-treatment level of Marker can then be compared to the level of Marker in the subject after the treatment commences, to determine the efficacy of the treatment. 
     A level of Marker or Marker activity in a subject may be determined at least once. Comparison of Marker levels, e.g., to another measurement of Marker level obtained previously or subsequently from the same patient, another patient, or a normal subject, may be useful in determining whether therapy according to the invention is having the desired effect, and thereby permitting adjustment of dosage levels as appropriate. Determination of Marker levels may be performed using any suitable sampling/expression assay method known in the art or described herein. Preferably, a tissue or fluid sample is first removed from a subject. Examples of suitable samples include blood, urine, tissue, mouth or cheek cells, and hair samples containing roots. Other suitable samples would be known to the person skilled in the art. Determination of protein levels and/or mRNA levels (e.g., Marker levels) in the sample can be performed using any suitable technique known in the art, including, but not limited to, enzyme immunoassay, is ELISA, radiolabelling/assay techniques, blotting/chemiluminescence methods, real-time PCR, and the like. 
     For clinical use, the compounds disclosed herein are formulated into pharmaceutical compositions (or formulations) for various modes of administration. It will be appreciated that compounds for use according to the invention may be administered together with a physiologically acceptable carrier, excipient, and/or diluent (i.e. one, two, or all three of these). The pharmaceutical compositions disclosed herein may be administered by any suitable route, preferably by oral, ocular (including intravitreal), rectal, nasal, topical (including buccal and sublingual), sublingual, transdermal, intrathecal, transtympanic transmucosal or parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. Preferably, the pharmaceutical compositions are administered ocularly. Other formulations may conveniently be presented in unit dosage form, e.g., tablets and sustained release capsules, and in liposomes, and may be prepared by any methods well known in the art of pharmacy. Pharmaceutical formulations are usually prepared by mixing the active substance, or a pharmaceutically acceptable salt thereof, with conventional pharmaceutically acceptable carriers, diluents or excipients. Examples of excipients are water, gelatin, gum arabicum, lactose, microcrystalline cellulose, starch, sodium starch glycolate, calcium hydrogen phosphate, magnesium stearate, talcum, colloidal silicon dioxide, and the like. Such formulations may also contain other pharmacologically active agents, and conventional additives, such as stabilizers, wetting agents, emulsifiers, flavouring agents, buffers, and the like. Usually, the amount of active compounds is between 0.1-95% by weight of the preparation, preferably between 0.2-20% by weight in preparations for parenteral use and more preferably between 1-50% by weight in preparations for oral administration. The formulations can be further prepared by known methods such as granulation, compression, microencapsulation, spray coating, etc. The formulations may be prepared by conventional methods in the dosage form of tablets, eye drops, creams, capsules, granules, powders, syrups, suspensions, suppositories or injections. Liquid formulations may be prepared by dissolving or suspending the active substance in water or other suitable vehicles. Tablets and granules may be coated in a conventional manner. To maintain therapeutically effective plasma concentrations for extended periods of time, compounds disclosed herein may be incorporated into slow release formulations. 
     The dose level and frequency of dosage of the specific compound will vary depending on a variety of factors including the potency of the specific compound employed, the metabolic stability and length of action of that compound, the patient&#39;s age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the condition to be treated, and the patient undergoing therapy. The daily dosage may, for example, range from about 0.001 mg to about 100 mg per kilo of body weight, administered singly or multiply in doses, e.g. from about 0.01 mg to about 25 mg each. Normally, such a dosage is given orally but parenteral administration may also be chosen. 
     Definitions 
     “Optional” or “optionally” means that the subsequently described event or circumstance may, but need not, occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. 
     The term “C 1 -C 6  alkyl” denotes a straight, branched or cyclic or partially cyclic alkyl group having from 1 to 6 carbon atoms, i.e. 1, 2, 3, 4, 5 or 6 carbon atoms. For the “C 1 -C 6  alkyl” group to comprise a cyclic portion it should be formed of 3 to 6 carbon atoms. For parts of the range “C 1 -C 6  alkyl” all subgroups thereof are contemplated, such as C 1 -C 5  alkyl, C 1 -C 4  alkyl, C 1 -C 3  alkyl, C 1 -C 2  alkyl, C 1  alkyl, C 2 -C 6  alkyl, C 2 -C 5  alkyl, C 2 -C 4  alkyl, C 2 -C 3  alkyl, C 2  alkyl, C 3 -C 6  alkyl, C 3 -C 5  alkyl, C 3 -C 4  alkyl, C 3  alkyl, C 4 -C 6  alkyl, C 4 -C 5  alkyl, C 4  alkyl, C 5 -C 6  alkyl, C 5  alkyl, and C 6  alkyl. Examples of “C 1 -C 6  alkyl” include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, cyclobutyl, cyclopropylmethyl, and straight, branched or cyclic or partially cyclic pentyl and hexyl etc. 
     When a term denotes a range, for instance “1 to 6 carbon atoms” in the definition of C 1 -C 6  alkyl, each integer is considered to be disclosed, i.e. 1, 2, 3, 4, 5 and 6. 
     The term “halo atom” means a halogen atom, and is preferably F, Cl, Br or I. 
     The term “C 5 -C 10  aryl” denotes an aromatic monocyclic or fused bicyclic hydrocarbon ring system comprising 6 to 10 ring atoms. Examples of “C 5 -C 10  aryl” groups include phenyl, indenyl, naphthyl, and naphthalene. 
     The term “C 1 -C 9  heteroaryl” denotes an aromatic monocyclic or fused bicyclic heteroaromatic ring system having 5 to 10 ring atoms in which 1 to 9 of the ring atoms are carbon and one or more of the ring atoms are selected from nitrogen, sulphur, and oxygen. Examples of “C 1 -C 9  heteroaryl” include furyl, pyrrolyl, thienyl, oxazolyl, isoxazolyl, imidazolyl, thiazolyl, isothiazolyl, pyridinyl, pyrimidinyl, tetrazolyl, quinazolinyl, indolyl, indolinyl, isoindolyl, isoindolinyl, pyrazolyl, pyridazinyl, pyrazinyl, quinolinyl, quinoxalinyl, thiadiazolyl, benzofuranyl, 2,3-dihydrobenzofuranyl, 1,3-benzodioxolyl, 1,4-benzodioxinyl, 2,3-dihydro-1,4-benzodioxinyl, benzothiazolyl, benzimidazolyl, benzothiadiazolyl, benzotriazolyl and chromanyl. 
     “An effective amount” refers to an amount of a compound for use according to the invention that confers a therapeutic effect on the treated subject. The therapeutic effect may be objective (i.e. measurable by some test or marker) or subjective (i.e. subject gives an indication of or feels an effect). 
     As used herein, the terms “administration” or “administering” mean a route of administration for a compound disclosed herein. Exemplary routes of administration include, but are not limited to, oral, ocular (such as intravitreal), topical, intravenous, intraperitoneal, intraarterial, and intramuscular. The preferred route of administration can vary depending on various factors, e.g. the components of the pharmaceutical composition comprising a compound disclosed herein, site of the potential or actual disease and severity of disease. 
     The terms “subject” and “patient” are used herein interchangeably. They refer to a human or another mammal (e.g., mouse, rat, rabbit, dog, cat, cattle, swine, sheep, horse or primate) that can be afflicted with or is susceptible to a disease or disorder but may or may not have the disease or disorder. It is preferred that the subject is human. 
     Compounds for use according to the invention may be disclosed by the name or chemical structure. If a discrepancy exists between the name of a compound and its associated chemical structure, then the chemical structure prevails. 
     Preparation of Compounds of the Invention 
     The compounds of Formulae (I) and (II) disclosed herein may be prepared by, or in analogy with, conventional methods. Appropriate reaction conditions for the individual reaction steps are known to a person skilled in the art. The necessary starting materials for preparing the compounds of Formulae (I) and (II) are either commercially available, or may be prepared by methods known in the art. 
     The compounds of Formulae (I) and (II) may possess one or more chiral carbon atoms, and they may therefore be obtained in the form of optical isomers, e.g., as a pure enantiomer, or as a mixture of enantiomers or as a mixture containing diastereomers. The separation of mixtures of optical isomers to obtain pure enantiomers is well known in the art and may, for example, be achieved by fractional crystallization of salts with optically active (chiral) acids or by chromatographic separation on chiral columns. 
     Particular experimental procedures for examples of the invention are described below. The processes may be carried out to give a compound of the invention in the form of a free base or as an acid addition salt. A pharmaceutically acceptable acid addition salt may be obtained by dissolving the free base in a suitable organic solvent and treating the solution with an acid, in accordance with conventional procedures for preparing acid addition salts from base compounds. Examples of addition salt forming acids are mentioned above. The chemicals used in the synthetic routes delineated herein may include, for example, solvents, reagents, catalysts, and protecting group and deprotecting group reagents. Examples of protecting groups are t-butoxycarbonyl (Boc), benzyl and trityl(triphenylmethyl). The methods described below may also additionally include steps, either before or after the steps described specifically herein, to add or remove suitable protecting groups in order to ultimately allow synthesis of the compounds. In addition, various synthetic steps may be performed in an alternate sequence or order to give the desired compounds. 
     Synthetic chemistry transformations and protecting group methodologies (protection and deprotection) useful in synthesizing applicable compounds are known in the art and include, for example, those described in R. Larock,  Comprehensive Organic Transformations , VCH Publishers (1989); T. W. Greene and P. G. M. Wuts,  Protective Groups in Organic Synthesis,  3rd Ed., John Wiley and Sons (1999); L. Fieser and M. Fieser,  Fieser and Fieser&#39;s Reagents for Organic Synthesis , John Wiley and Sons (1994); and L. Paquette, ed.,  Encyclopedia of Reagents for Organic Synthesis , John Wiley and Sons (1995) and subsequent editions thereof. 
     The invention will now be further illustrated by the following non-limiting examples. The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. All references and publications cited herein are hereby incorporated by reference in their entirety. 
     
       
         
         
             
             
         
       
     
     In general synthetic procedure 1, phthalic anhydride 1 undergoes condensation-cyclo-dehydration to produce phthalimide 2 followed by hydrolysis to form phthalamic acid 3. The regioisomers of phthalamic acid 3 are then separated via preparative HPLC. 6   
     
       
         
         
             
             
         
       
     
     In general, synthetic procedure 2, phthalic anhydride 4 is reacted with tert-butanol followed by separation of the regioisomeric mono esters by supercritical fluid chromatography (SFC) to produce phthalate mono-t-butyl ester 5. Phthalate mono-t-butyl ester 5 subsequently undergoes coupling deprotection resulting in phthalamic acid 6. 6    
     Palladium-catalysed coupling could be used to replace the bromine of phthalate mono-t-butyl ester 5 or phthalamic acid 6 with alternative substituents. 6    
     EXAMPLES 
     Examples 1 and 2 
     
       
         
         
             
             
         
       
     
     Phthalamide 6 was degraded under assay conditions (see description of Neurotensin (NTS) scintillation proximity assay (SPA) below) to afford the two corresponding phthalimide hydrolysis products, 5-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid (Example 1) and 4-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid (Example 2). 6    
     Alternatively, Examples 1 and 2 may be prepared in accordance with general synthetic procedures 1 and/or 2. 
     Examples 3 to 30 
     Examples 3 to 30 can be prepared in accordance with general synthetic procedures 1 and/or 2. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Ex. 
                 Compound Name 
                 Structure 
               
               
                   
               
             
            
               
                  3 
                 2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  4 
                 2-methyl-6-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  5 
                 5-chloro-2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  6 
                 5-methyl-2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  7 
                 2-[(6-methylpyridin-2- yl)carbamoyl]-5-(propan-2- yl)benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  8 
                 2-[(6-methylpyridin-2- yl)carbamoyl]-5- (trifluoromethyl)benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                  9 
                 2-[(6-methylpyridin-2- yl)carbamoyl]-5-nitrobenzoic acid  
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 10 
                 4-[(6-methylpyridin-2- yl)carbamoyl]-[1,1&#39;-bi phenyl]-3- carboxylic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 11 
                 4-chloro-2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 12 
                 4-methyl-2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 13 
                 2-[(6-methylpyridin-2- yl)carbamoyl]-4- (trifluoromethyl)benzoic acid  
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 14 
                 4,5-dichloro-2-[(6-methylpyridin- 2-yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 15 
                 4,5-dimethyl-2-[(6-methylpyridin- 2-yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 16 
                 3-methyl-2-[(6-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 17 
                 5-bromo-2-[(butan-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 18 
                 5-bromo-2-[(propan-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 19 
                 5-bromo-2- (phenylcarbamoyl)benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 20 
                 5-bromo-2-[(3- methylphenyl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 21 
                 5-bromo-2-[(pyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 22 
                 5-bromo-2-[(6-chloropyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 23 
                 5-bromo-2-[(4-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 24 
                 5-bromo-2-[(3-methylpyridin-2- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 25 
                 5-bromo-2-[(6-methylpyridin-3- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 26 
                 5-bromo-2-[(2-methylpyridin-4- yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 27 
                 5-bromo-2-[(2-methylpyrimidin- 4-yl)carbamoyl]benzoic acid 
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 28 
                 2-[(6-methoxypyridin-2- yl)carbamoyl]-5- (trifluoromethyl)benzoic acid  
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 29 
                 2-[(5,6-dimethylpyridin-2- yl)carbamoyl]-5- (trifluoromethyl)benzoic acid    
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 30 
                 2-[(5,6,7,8-tetrahydroquinolin-2- yl)carbamoyl]-5- (trifluoromethyl)benzoic acid  
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
            
           
         
       
     
     Biological Data 
     Neurotensin Scintillation Proximity Assay 
     The exemplified compounds of the invention were tested in a Neurotensin (NTS) scintillation proximity assay (SPA) and the IC 50  data is shown in the table below. NTS, which is a 13 amino acid neuropeptide, is a sortilin ligand. The IC 50  is a measure of the amount of the compound required to inhibit the binding of NTS to sortilin by 50%. The skilled person will recognise that the lower the IC 50  value, the less of the compound needed to achieve the desired effect, and as a result, the chances of undesirable off-target effects are reduced. 
     Compound affinity was determined by measuring the displacement of 3H-neurotensin binding to hSortilin in SPA format. Total volume of 40 μl in 50 mM HEPES pH 7.4 assay buffer containing 100 mM NaCl, 2.0 mM CaCl 2 , 0.1% BSA and 0.1% Tween-20. Compound pre-incubation for 30 min at RT with 150 nM of 6his-Sortilin before 5 nM [3H]-Neurotensin and Ni chelate imaging beads (Perkin Elmer) were added, after 6 h plate was read on a ViewLux with 360 s exposure time. Dose-response evaluation of compounds was performed with 10 concentrations of drugs (covering 3 decades). IC 50  values were calculated by nonlinear regression using the sigmoid concentration-response (variable slope) using Xlfit 4 (IDBS, UK). All values reported are average of at least 4 determinations. 6    
     The data in the table below shows that the compounds disclosed herein are sortilin inhibitors. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Example 
                 NTS IC 50  (nM) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 1 
                  710 
               
               
                   
                 2 
                 12000  
               
               
                   
                 3 
                 15%* 
               
               
                   
                 4 
                  5%* 
               
               
                   
                 5 
                 1400 
               
               
                   
                 6 
                 6400 
               
               
                   
                 7 
                 1100 
               
               
                   
                 8 
                  330 
               
               
                   
                 9 
                 1700 
               
               
                   
                 10 
                  2%* 
               
               
                   
                 11 
                 69%* 
               
               
                   
                 12 
                 57%* 
               
               
                   
                 13 
                 9100 
               
               
                   
                 14 
                  830 
               
               
                   
                 15 
                 3400 
               
               
                   
                 16 
                 43%* 
               
               
                   
                 17 
                 30%* 
               
               
                   
                 18 
                 35%* 
               
               
                   
                 19 
                 69%* 
               
               
                   
                 20 
                 5200 
               
               
                   
                 21 
                 3600 
               
               
                   
                 22 
                 1600 
               
               
                   
                 23 
                 2400 
               
               
                   
                 24 
                 64%* 
               
               
                   
                 25 
                 70%* 
               
               
                   
                 26 
                 1800 
               
               
                   
                 27 
                  490 
               
               
                   
                 28 
                 1300 
               
               
                   
                 29 
                  170 
               
               
                   
                 30 
                  100 
               
               
                   
                   
               
               
                   
                 *% inhibition at 50 μM. 
               
            
           
         
       
     
     Diabetic Mouse Model 
     Flash electroretinography (fERG) was used to measure the electrical response of the light sensitive cells of the retina in mice both prior to streptozocin (STZ) induction of diabetes (baseline) and 8 weeks after induction. Mice were exposed to increasing intensities of light flashes and the resulting electrical responses, measured in amplitude, were recorded. The skilled person will recognise that a cell with a higher measured amplitude is indicative of a healthy cell whilst cells with lower amplitudes is indicative of a damaged cell which is no longer functioning optimally. In the experimental group, the mice were administered with a polyclonal anti-sortilin antibody (2 ul of a 1 μg/μl solution in Dulbecco&#39;s Phosphate buffered saline) by intravitrial administration whereas in the control group the mice were administered with the vehicle only (Dulbecco&#39;s Phosphate buffered saline). All other variables, such as food intake, diet, exercise levels and exposure to environmental enrichment were kept the same between the two groups. 
       FIGS.  1  and  2    show the reduction in the fERG response 8 weeks after induction compared to the baseline for both the experimental group and the control group. As can be seen from the data, the reduction in fERG response was smaller for the experimental group compared to the control group. This shows that administration of the polyclonal anti-sortilin antibody was able to better protect the retinal cells of the mice from damage compared to the vehicle control group, and therefore suggestive of reducing disease progression. Without wishing to be bound by theory, it is thought that the polyclonal antibody competes with sortilin to bind to p75NTR thereby preventing activation of said receptor by sortilin. 
       FIG.  1    shows the “a wave” component of the fERG response.  FIG.  2    shows the “b wave” component of the fERG response. This data demonstrates that interference with the p75NTR/sortilin/pro-neurotrophin and/or sortilin/pro-neurotrophin complex is effective across a range of photosensitive cell-types. The fact that the effect is not limited to a single cell-type is advantageous in that multiple cell-types can be targeted simultaneously and produce a more efficacious therapy to address diabetic retinopathy as a result. 
     The results of this study demonstrate that sortilin antagonists are useful in the prevention or treatment of diabetic retinopathy. 
     The study was repeated but modified such that the mice in the control group were administered twice with Example 8 of the application (a sortilin inhibitor) by intravitreal administration (2 μl of a 1 μg/μl solution in Dulbecco&#39;s Phosphate buffered saline), rather than with the polyclonal anti-sortilin antibody. 
     As can be seen from the data in  FIGS.  3  and  4   , the reduction in the fERG response 8 weeks after induction compared to the baseline was smaller for the experimental group compared to the control group. This shows that administration of the sortilin inhibitor was able to better protect the retinal cells of the mice from damage compared to the vehicle control group, and therefore suggestive of reducing disease progression. Surprisingly, the protective effect of the small molecule sortilin inhibitor (Example 8) was greater than that of the polyclonal antibody demonstrated in the first study. 
     The results of this study demonstrate that the compounds of Formula (I) and (II) disclosed herein are useful in the prevention or treatment of diabetic retinopathy. 
     Numbered Embodiments 
     Numbered embodiment 1. A sortilin antagonist for use in the prevention or treatment of diabetic retinopathy.
 
Numbered embodiment 2. The sortilin antagonist for use according to numbered embodiment 1, wherein
         (i) the sortilin antagonist disrupts an interaction between a sortilin or sortilin-related molecule and a pro-neurotrophin molecule; and/or   (ii) the sortilin antagonist disrupts an interaction between a sortilin or sortilin-related molecule and a p75NTR molecule.
 
Numbered embodiment 3. The sortilin antagonist for use according to numbered embodiment 2, wherein the sortilin is mature sortilin or wherein the sortilin-related molecule is SorCS2.
 
Numbered embodiment 4. The sortilin antagonist for use according to numbered embodiment 1 to 3, wherein the sortilin antagonist is a sortilin inhibitor.
 
Numbered embodiment 5. The sortilin antagonist for use according to any one of numbered embodiments 1 to 4, wherein the sortilin antagonist has a molecular weight of &lt;2000 Da, preferably wherein the sortilin antagonist has a molecular weight of &lt;1000 Da.
 
Numbered embodiment 6. The sortilin antagonist for use according to any one of numbered embodiments 1 to 5, wherein the sortilin antagonist is a compound of Formula (I):
       

     
       
         
         
             
             
         
       
     
     or a pharmaceutically acceptable salt, solvate, hydrate, geometrical isomer, tautomer, optical isomer, N-oxide, and/or prodrug thereof, wherein
 
Y is selected from the group consisting of —O—, —NR 5 —, and —S—;
 
Z is selected from the group consisting of optionally substituted C 1 -C 6  alkyl, optionally substituted C 6 -C 10  aryl, and optionally substituted C 1 -C 9  heteroaryl;
 
A, B, C and D are each independently selected from the group consisting of H, optionally substituted C 1 -C 6  alkyl, halo, NO 2 , optionally substituted C 6 -C 10  aryl, optionally substituted C 1 -C 9  heteroaryl, —OR 6 , NR 7 R 8 , —SR 9 , —C(O)OR 10 , —C(O)NR 11 R 12 , —C(O)SR 13 , C(O 2 )SR 14 ;
 
R 1 , R 4 , R 5 , R 6 , R 9 , R 10 , R 13 , and R 14  are each independently selected from the group consisting of H and C 1 -C 6  alkyl group, wherein the C 1 -C 6  alkyl is optionally substituted with one or more halo atoms; and
 
R 2 , R 3 , R 7 , R 8 , R 11 , and R 12  are each independently selected from the group consisting of H and C 1 -C 6  alkyl, wherein the C 1 -C 6  alkyl is optionally substituted with one or more halo atoms, or R 2  and R 3 , R 7  and R 8 , and/or R 11  and R 12  can be taken together with the nitrogen atom to which they are attached to from a 5- or 6-membered heterocycle, optionally substituted with one or more halo atoms;
 
Numbered embodiment 7. The sortilin antagonist for use according to numbered embodiment 6, wherein Y is —NR 5 —, preferably Y is —NH—.
 
Numbered embodiment 8. The sortilin antagonist for use according to numbered embodiment 6 or 7, wherein A and D are H.
 
Numbered embodiment 9. The sortilin antagonist for use according to any one of numbered embodiments 6 to 8, wherein B and C are independently selected from the group consisting of H, halo, CF 3 , NO 2 , and C 1 -C 3  alkyl.
 
Numbered embodiment 10. The sortilin antagonist for use according to any one of numbered embodiments 6 to 9, wherein C is H.
 
Numbered embodiment 11. The sortilin antagonist for use according to any one of numbered embodiments 6 to 10, wherein B is selected from the group consisting of halo and CF 3 , preferably wherein B is Br or CF 3 .
 
Numbered embodiment 12. The sortilin antagonist for use according to any one of numbered embodiments 6 to 11, wherein Z is an optionally substituted C 6 -C 10  aryl or an optionally substituted C 1 -C 9  heteroaryl, more preferably Z is an optionally substituted phenyl, an optionally substituted pyridyl, or an optionally substituted pyrimidinyl.
 
Numbered embodiment 13. The sortilin antagonist for use according to numbered embodiment 12, wherein Z is substituted with one or more substituents independently selected from the group consisting of —OR 15 , halo, and C 1 -C 4  alkyl, wherein R 15  is H, halo, and C 1 -C 3  alkyl, preferably wherein Z is substituted with one or more substituents selected from the group consisting of Cl, —OMe, and Me;
         and/or wherein an alkylene group is attached to two adjacent atoms of group Z to form a 5- or 6-membered partially saturated or saturated ring, optionally wherein the alkylene group is substituted with one or more halo atoms.
 
Numbered embodiment 14. The sortilin antagonist for use according to any preceding claim, wherein the sortilin antagonist is
   2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-methyl-6-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(propan-2-yl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-nitrobenzoic acid;   4-[(6-methylpyridin-2-yl)carbamoyl]-[1,1′-biphenyl]-3-carboxylic acid;   4-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-4-(trifluoromethyl)benzoic acid;   4,5-dichloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4,5-dimethyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   3-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(butan-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(propan-2-yl)carbamoyl]benzoic acid;   5-bromo-2-(phenylcarbamoyl)benzoic acid;   5-bromo-2-[(3-methylphenyl)carbamoyl]benzoic acid;   5-bromo-2-[(pyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-chloropyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(4-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(3-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-methylpyridin-3-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyridin-4-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyrimidin-4-yl)carbamoyl]benzoic acid;   2-[(6-methoxypyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6-dimethylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6,7,8-tetrahydroquinolin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid,
 
or a pharmaceutically acceptable salt, solvate, hydrate, tautomer, optical isomer, N-oxide, and/or prodrug thereof, preferably the sortilin antagonist is
   5-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-chloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-methyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(propan-2-yl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-5-nitrobenzoic acid;   4-bromo-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   2-[(6-methylpyridin-2-yl)carbamoyl]-4-(trifluoromethyl)benzoic acid;   4,5-dichloro-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   4,5-dimethyl-2-[(6-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(3-methylphenyl)carbamoyl]benzoic acid;   5-bromo-2-[(pyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(6-chloropyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(4-methylpyridin-2-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyridin-4-yl)carbamoyl]benzoic acid;   5-bromo-2-[(2-methylpyrimidin-4-yl)carbamoyl]benzoic acid;   2-[(6-methoxypyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6-dimethylpyridin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;   2-[(5,6,7,8-tetrahydroquinolin-2-yl)carbamoyl]-5-(trifluoromethyl)benzoic acid;
 
or a pharmaceutically acceptable salt, solvate, hydrate, tautomer, optical isomer, N-oxide, and/or prodrug thereof.
       

     Numbered embodiment 15. A pharmaceutical formulation comprising a sortilin antagonist as defined in any of numbered embodiments 1 to 14 and one or more pharmaceutically acceptable carriers or excipients, for use in the treatment or prevention of diabetic retinopathy, preferably wherein the formulation is an ophthalmic formulation. 
     REFERENCES 
     
         
         1. Wong, T. Y., et al., Diabetic retinopathy. Nat Rev Dis Primers, 2016. 2: p. 16012. NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in diabetes since 1980: a pooled analysis of 751 population-based studies with 4.4 million participants (vol 387, pg 1513, 2016). Lancet, 2017. 389(10068): p. E2-E2. 
         2. Antonetti, D. A., R. Klein, and T. W. Gardner, Diabetic retinopathy. N Engl J Med, 2012. 366(13): p. 1227-39. 
         3. Jansen, P., et al., Roles for the pro-neurotrophin receptor sortilin in neuronal development, aging and brain injury.  Nature Neuroscience  (2007), 10(11), pp. 1449-1457. 
         4. Tenk, H. K., et al., ProBDNF induces neuronal apoptosis via activation of a receptor complex of p75NTR and sortilin.  J Neuroscience  (2005), 10(11), pp. 1449-1457. 
         5. Nykjaer, A., et al., Sortilin is essential for proNGF-induced neuronal cell death.  Nature  (2004), 427(6977), pp. 843-848. 
         6. T. J. Schroder et al. The identification of AF38469: An orally bioavailable inhibitor of the VPS10P family sorting receptor Sortilin, Bioorganic &amp; Medicinal Chemistry Letters 24 (2014) 177-180. 
       
    
     Sequences Referenced Throughout the Specification and Forming Part of the Description. 
       
     
       
         
           
               
            
               
                 SEQ ID NO: 1 
               
               
                 (full length sortilin- isoform 1) 
               
            
           
           
               
               
            
               
                 1 
                 MERPWGAADG LSRWPHGLGL LLLLQLLPPS TLSQDRLDAP 
               
               
                   
               
               
                   
                 PPPAAPLPRW 
               
               
                   
               
               
                 51 
                 SGPIGVSWGL RAAAAGGAFP RGGRWRRSAP GEDEECGRVR 
               
               
                   
               
               
                   
                 DFVAKLANNT 
               
               
                   
               
               
                 101 
                 HQHVFDDLRG SVSLSWVGDS TGVILVLTTF HVPLVIMTFG 
               
               
                   
               
               
                   
                 QSKLYRSEDY 
               
               
                   
               
               
                 151 
                 GKNFKDITDL INNTFIRTEF GMAIGPENSG KVVLTAEVSG 
               
               
                   
               
               
                   
                 GSRGGRIFRS 
               
               
                   
               
               
                 201 
                 SDFAKNFVQT DLPFHPLTQM MYSPQNSDYL LALSTENGLW 
               
               
                   
               
               
                   
                 VSKNFGGKWE 
               
               
                   
               
               
                 251 
                 EIHKAVCLAK WGSDNTIFFT TYANGSCKAD LGALELWRTS 
               
               
                   
               
               
                   
                 DLGKSFKTIG 
               
               
                   
               
               
                 301 
                 VKIYSFGLGG RFLFASVMAD KDTTRRIHVS TDQGDTWSMA 
               
               
                   
               
               
                   
                 QLPSVGQEQF 
               
               
                   
               
               
                 351 
                 YSILAANDDM VFMHVDEPGD TGFGTIFTSD DRGIVYSKSL 
               
               
                   
               
               
                   
                 DRHLYTTTGG 
               
               
                   
               
               
                 401 
                 ETDFTNVTSL RGVYITSVLS EDNSIQTMIT FDQGGRWTHL 
               
               
                   
               
               
                   
                 RKPENSECDA 
               
               
                   
               
               
                 451 
                 TAKNKNECSL HIHASYSISQ KLNVPMAPLS EPNAVGIVIA 
               
               
                   
               
               
                   
                 HGSVGDAISV 
               
               
                   
               
               
                 501 
                 MVPDVYISDD GGYSWTKMLE GPHYYTILDS GGIIVAIEHS 
               
               
                   
               
               
                   
                 SRPINVIKFS 
               
               
                   
               
               
                 551 
                 TDEGQCWQTY TFTRDPIYFT GLASEPGARS MNISIWGFTE 
               
               
                   
               
               
                   
                 SFLTSQWVSY 
               
               
                   
               
               
                 601 
                 TIDFKDILER NCEEKDYTIW LAHSTDPEDY EDGCILGYKE 
               
               
                   
               
               
                   
                 QFLRLRKSSM 
               
               
                   
               
               
                 651 
                 CQNGRDYVVT KQPSICLCSL EDFLCDFGYY RPENDSKCVE 
               
               
                   
               
               
                   
                 QPELKGHDLE 
               
               
                   
               
               
                 701 
                 FCLYGREEHL TTNGYRKIPG DKCQGGVNPV REVKDLKKKC 
               
               
                   
               
               
                   
                 TSNFLSPEKQ 
               
               
                   
               
               
                 751 
                 NSKSNSVPII LAIVGLMLVT VVAGVLIVKK YVCGGRFLVH 
               
               
                   
               
               
                   
                 RYSVLQQHAE 
               
               
                   
               
               
                 801 
                 ANGVDGVDAL DTASHTNKSG YHDDSDEDLL E 
               
               
                   
               
            
           
           
               
            
               
                 SEQ ID NO: 2 
               
               
                 (full length sortilin- isoform 2) 
               
            
           
           
               
               
            
               
                 1 
                 MERPWGAADG LSRWPHGLGL LLLLQLLPPS TLSQDRLDAP 
               
               
                   
               
               
                   
                 PPPAAPLPRW 
               
               
                   
               
               
                 51 
                 SGPIGVSWGL RAAAAGGAFP RGGRWRRSAP GEDEECGRVR 
               
               
                   
               
               
                   
                 DFVAKLANNT 
               
               
                   
               
               
                 101 
                 HQHVFDDLRG SVSLSWVGDS TGVILVLTTF HVPLVIMTFG 
               
               
                   
               
               
                   
                 QSKLYRSEDY 
               
               
                   
               
               
                 151 
                 GKNFKDITDL INNTFIRTEF GMAIGPENSG KVVLTAEVSG 
               
               
                   
               
               
                   
                 GSRGGRIFRS 
               
               
                   
               
               
                 201 
                 SDFAKNFVQT DLPFHPLTQM MYSPQNSDYL LALSTENGLW 
               
               
                   
               
               
                   
                 VSKNFGGKWE 
               
               
                   
               
               
                 251 
                 EIHKAVCLAK WGSDNTIFFT TYANGSCTDL GALELWRTSD 
               
               
                   
               
               
                   
                 LGKSFKTIGV 
               
               
                   
               
               
                 301 
                 KIYSFGLGGR FLFASVMADK DTTRRIHVST DQGDTWSMAQ 
               
               
                   
               
               
                   
                 LPSVGQEQFY 
               
               
                   
               
               
                 351 
                 SILAANDDMV FMHVDEPGDT GFGTIFTSDD RGIVYSKSLD 
               
               
                   
               
               
                   
                 RHLYTTTGGE 
               
               
                   
               
               
                 401 
                 TDFTNVTSLR GVYITSVLSE DNSIQTMITF DQGGRWTHLR 
               
               
                   
               
               
                   
                 KPENSECDAT 
               
               
                   
               
               
                 451 
                 AKNKNECSLH IHASYSISQK LNVPMAPLSE PNAVGIVIAH 
               
               
                   
               
               
                   
                 GSVGDAISVM 
               
               
                   
               
               
                 501 
                 VPDVYISDDG GYSWTKMLEG PHYYTILDSG GIIVAIEHSS 
               
               
                   
               
               
                   
                 RPINVIKFST 
               
               
                   
               
               
                 551 
                 DEGQCWQTYT FTRDPIYFTG LASEPGARSM NISIWGFTES 
               
               
                   
               
               
                   
                 FLTSQWVSYT 
               
               
                   
               
               
                 601 
                 IDFKDILERN CEEKDYTIWL AHSTDPEDYE DGCILGYKEQ 
               
               
                   
               
               
                   
                 FLRLRKSSVC 
               
               
                   
               
               
                 651 
                 QNGRDYVVTK QPSICLCSLE DFLCDFGYYR PENDSKCVEQ 
               
               
                   
               
               
                   
                 PELKGHDLEF 
               
               
                   
               
               
                 701 
                 CLYGREEHLT TNGYRKIPGD KCQGGVNPVR EVKDLKKKCT 
               
               
                   
               
               
                   
                 SNFLSPEKQN 
               
               
                   
               
               
                 751 
                 SKSNSVPIIL AIVGLMLVTV VAGVLIVKKY VCGGRFLVHR 
               
               
                   
               
               
                   
                 YSVLQQHAEA 
               
               
                   
               
               
                 801 
                 NGVDGVDALD TASHTNKSGY HDDSDEDLLE 
               
               
                   
               
            
           
           
               
            
               
                 SEQ ID NO: 3 
               
               
                 (mature sortilin) 
               
            
           
           
               
               
            
               
                 1 
                 MTFGQSKLYR SEDYGKNFKD ITDLINNTFI RTEFGMAIGP 
               
               
                   
               
               
                   
                 ENSGKVVLTA 
               
               
                   
               
               
                 51 
                 EVSGGSRGGR IFRSSDFAKN FVQTDLPFHP LTQMMYSPQN 
               
               
                   
               
               
                   
                 SDYLLALSTE 
               
               
                   
               
               
                 101 
                 NGLWVSKNFG GKWEEIHKAV CLAKWGSDNT IFFTTYANGS 
               
               
                   
               
               
                   
                 CTDLGALELW 
               
               
                   
               
               
                 151 
                 RTSDLGKSFK TIGVKIYSFG LGGRFLFASV MADKDTTRRI 
               
               
                   
               
               
                   
                 HVSTDQGDTW 
               
               
                   
               
               
                 201 
                 SMAQLPSVGQ EQFYSILAAN DDMVFMHVDE PGDTGFGTIF 
               
               
                   
               
               
                   
                 TSDDRGIVYS 
               
               
                   
               
               
                 251 
                 KSLDRHLYTT TGGETDFTNV TSLRGVYITS VLSEDNSIQT 
               
               
                   
               
               
                   
                 MITFDQGGRW 
               
               
                   
               
               
                 301 
                 THLRKPENSE CDATAKNKNE CSLHIHASYS ISQKLNVPMA 
               
               
                   
               
               
                   
                 PLSEPNAVGI 
               
               
                   
               
               
                 361 
                 VIAHGSVGDA ISVMVPDVYI SDDGGYSWTK MLEGPHYYTI 
               
               
                   
               
               
                   
                 LDSGGIIVAI 
               
               
                   
               
               
                 401 
                 EHSSRPINVI KFSTDEGQCW QTYTFTRDPI YFTGLASEPG 
               
               
                   
               
               
                   
                 ARSMNISIWG 
               
               
                   
               
               
                 451 
                 FTESFLTSQW VSYTIDFKDI LERNCEEKDY TIWLAHSTDP 
               
               
                   
               
               
                   
                 EDYEDGCILG 
               
               
                   
               
               
                 501 
                 YKEQFLRLRK SSVCQNGRDY VVTKQPSICL CSLEDFLCDF 
               
               
                   
               
               
                   
                 GYYRPENDSK 
               
               
                   
               
               
                 551 
                 CVEQPELKGH DLEFCLYGRE EHLTTNGYRK IPGDKCQGGV 
               
               
                   
               
               
                   
                 NPVREVKDLK 
               
               
                   
               
               
                 601 
                 KKCTSNFLSP EKQNSKSNSV PIILAIVGLM LVTVVAGVLI 
               
               
                   
               
               
                   
                 VKKYVCGGRF 
               
               
                   
               
               
                 651 
                 LVHRYSVLQQ HAEANGVDGV DALDTASHTN KSGYHDDSDE 
               
               
                   
               
               
                   
                 DLLE