Field of the invention

5 The present invention provides novel cell-permeable fumarate acyl

mercaptoethylamines (FAMs). These compounds have similarities to fumaric acid

esters (FAEs), but with significant improvements in a number of clinically relevant

properties. The invention also relates to the use of the FAMs in medicine notably in the treatment of multiple sclerosis, psoriasis and non-alcoholic steatohepatitis.

10

Background of the invention

Dimethyl fumarate (DMF), the best known FAE, is approved as part of a mixture for the treatment of psoriasis (as part of Fumaderm), and is approved for the treatment of

multiple sclerosis (Tecfedira). Fumaderm is a tablet containing a mixture of monoethyl

15 fumarate and dimethyl fumarate salts which is approved for the treatment of psoriasis.

Tecfedira is an oral formulation of DMF, which is prescribed for treatment of relapsing remitting multiple sclerosis. Both treatments lead to side effects. Recent data

suggested that patients were 1 .4 times more likely to discontinue Tecfedira treatment after six months than those treated with interferons and almost twice as frequently as

20 patients treated with fingolimod, mostly due to Gl side effects. Typical side effects of

FAE therapy include gastrointestinal upset including nausea, vomiting, and diarrhoea;

and transient flushing of the skin. Significant flushing incidences have also been

reported in patients with psoriasis after administration of dimethyl fumarate (Artuc et al., Br J Dermatology Preprint, 2006, 154, 21 ). Longer term treatment can also lead to

25 leucopoenia (reduced lymphocyte counts) and there are also concerns that chronic

treatment with Tecfedira can lead to progressive multifocal leukoencephalopathy (PML) in a small number of cases. Dimethyl fumarate is also rapidly converted in vivo to

monomethyl fumarate upon administration to patients, meaning that the majority of the activity likely comes from this compound. Oral bioavailability of dimethyl fumarate is

30 also low. (Dibbert et al., 2013 Arch. Dermatol. Res. 2013; 305: 447-451 ). As

mentioned in WO2014100728 a patent application describing DMF analogues from

Biogen, who market Tecfedira, there is a need for DMF analogs having an improved pharmacokinetic profile. This improved pharmacokinetic profile could come from a

number of sources, including improved cell permeability, reduced efflux, increased oral

35 bioavailability and longer half-life. Other fumaric acid derivatives have also been described (Joshi and Strebel, WO 2002/055063, US 2006/0205659, and US 7,157,423 (amide compounds and protein- fumarate conjugates); Joshi et al, WO 2002/055066 and Joshi and Strebel, US

6,355,676 (mono and dialkyl esters); Joshi and Strebel, WO 2003/087174 (carbocyclic and oxacarbocylic compounds); Joshi et al., WO 2006/122652 (thiosuccinates); Joshi et al., US 2008/0233185 (dialkyl and diaryl esters); Nielsen and Bundgaard, J Pharm Sci 1988, 77(4), 285-298 (glycolamide ester prodrugs); and Nilsson et al., US

2008/0004344 (salts)) have been developed in an effort to overcome the deficiencies of current FAE therapy. Controlled release pharmaceutical compositions comprising fumaric acid esters have also been disclosed by Nilsson and Mijller, WO 2007/042034; by Nilsson and Rupp, US 2012/0034274 and US 2012/0034303. However, none of these derivatives have yet been approved clinically.

DMF and MMF probably exert their in vivo activities via at least four mechanisms. First, they stimulate cytoprotective and anti-inflammatory responses via activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-dependent anti-oxidant response pathway (Gold et al., 2012 Clin. Immunol. 2012; 142: 44-48). Second, they inhibit nuclear factor kappa-light-chain-enhancer of activated B cells (NF-KB)-driven processes (Gerdes et al., 2007 Br. J. Dermatol. 2007; 156: 838-842), resulting in downstream reduction in inflammatory cytokine production, altered maturation and function of antigen-presenting cells, and immune deviation of T helper cells (Th) from the Th1 and Th17 profile to a Th2 phenotype (Ghoreschi et al., 201 1 J. Exp. Med. 201 1 ; 208: 2291-2303). Third, they can bind thiol groups and modulate glutathione availability and production, which impacts cellular responses to oxidative stress (Dibbert et al., 2013 Arch. Dermatol. Res. 2013; 305: 447-451 ). Fourth, agonism of G- protein coupled receptor 109A (GPR109A, also known as the hydroxycarboxylic acid receptor 2 (HCA2)) by DMF and MMF reduces neutrophil adhesion, migration, and recruitment to the CNS during EAE (Chen et al., 2014 J. Clin. Invest. 2014; 124: 2188- 2192). However, the potency of some of these interactions is low, with EC50s in the micromolar range.

DMF has shown clinical utility in treatment of multiple sclerosis, but the combination of low oral bioavailability, rapid conversion to the less active MMF and relatively low potency probably lead to a requirement for bidaily or tridaily dosing and many patients do not respond effectively to treatment (26-27% of patients still had a relapse within the DEFINE trial, as opposed to 46% of patients on placebo (N Engl J Med 2012;

367:1098-1 107)). Accordingly, there is a need of providing fumarate drugs with improved properties to obtain efficient treatment of diseases or disorders requiring or treatable with fumarate. Description of the invention

The present invention describes a new class of fumaric acid derivatives, with improved properties. These fumarate acyl mercaptoethylamines (FAMs) show improved cell permeability (as shown by caco-2 permeability) and improved potency in multiple different assays when compared to dimethyl fumarate and monomethyl fumarate.

One advantage of the compounds of the invention is therefore their improved cell permeability.

Another advantage of the compounds of the invention is their reduced efflux.

Another advantage of the compounds of the invention is their improved potency.

Other potential advantages of the compounds of the invention include improved oral bioavailability, improved tolerability and reduced side effects.

Other potential advantages of the compounds include longer half-life, as shown by increased plasma, hepatocyte or microsome half-life, increased solubility and improved formulatability.

The present invention provides a FAM of Formula (I)

Formula (I)

Wherein:

X ₂ is S or NH,

Ri is H or C0 ₂ R ₅ or C(=0)NR ₅ R ₆ ,

R ₂ is H or CO2R5 or C(=0)NR ₅ R ₆ ,

R ₃ is Me, Et, iPr, nPr, nBu, sBu, iBu or tBu,

R ₄ is Me, Et, iPr, nPr, nBu, sBu, iBu or tBu,

R ₅ is H, Me, Et, iPr, nPr, nBu, sBu, or iBu,

R ₆ is H, Me, Et, iPr, nPr, nBu, sBu, or iBu, or a pharmaceutically acceptable salt thereof.

Compounds according to the present invention can be used to in medicine to treat disease or disorders or they can be used in medicine or medical research. The compounds can be used in the prevention or treatment of disorders or diseases having a component which responds to activation of Nrf2 or inhibition of the N FKB pathway or where FAEs have shown potential.

If some of the compounds disclosed herein are already known they are hereby disclaimed; thus the invention relates to the compounds as such provided that they are novel. The invention relates to the compounds disclosed herein for use in medicine, notably in the treatment of multiple sclerosis, non-alcoholic steatohepatitis or psoriasis. Other uses of the compounds appear from the description herein.

The present invention therefore relates to novel compounds as such and to the compounds for use in medicine, notably in the treatment of inflammatory diseases or disorders, such as multiple sclerosis (Joshi and Strebel, WO 1998/52549 and U.S. Pat. No. 6,436,992; Went and Lieberburg, US 2008/0089896; Schimrigk et al., Eur J Neurology 2006, 13, 604-610; and Schilling et al., Clin Experimental Immunology 2006, 145, 101 -107), psoriasis (Joshi and Strebel, WO 1999/49858 and U.S. Pat. No.

6,277,882; Mrowietz and Asadullah, Trends Mol Med 2005, 1 1 1 (1 ), 43-48; and Yazdi and Mrowietz, Clinics Dermatology 2008, 26, 522-526); asthma and chronic obstructive pulmonary diseases (Joshi et al., WO 2005/023241 and US 2007/0027076); cardiac insufficiency including left ventricular insufficiency, myocardial infarction and angina pectoris (Joshi et al., WO 2005/023241 ; Joshi et al., US 2007/0027076); mitochondrial and neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, retinopathia pigmentosa and mitochondrial encephalomyopathy (Joshi and Strebel, WO 2002/055063, US 2006/0205659, U.S. Pat. No. 6,509,376, U.S. Pat. No. 6,858,750, and U.S. Pat. No. 7,157,423); transplantation (Joshi and Strebel, WO 2002/055063, US 2006/0205659, U.S. Pat. No. 6,359,003, U.S. Pat. No. 6,509,376, and U.S. Pat. No. 7,157,423; and Lehmann et al., Arch Dermatol Res 2002, 294, 399-404); autoimmune diseases (Joshi and Strebel, WO 2002/055063, U.S. Pat. No. 6,509,376, U.S. Pat. No. 7,157,423, and US 2006/0205659); ischemia and reperfusion injury (Joshi et al., US 2007/0027076); AGE-induced genome damage (Heidland, WO 2005/027899); inflammatory bowel diseases such as Crohn's disease and ulcerative colitis; arthritis; and others (Nilsson et al., WO 2006/037342 and Nilsson and Muller, WO 2007/042034). The compounds of the invention may after administration liberate monomethylfumarate (MMF), MMFcoenzyme A, fumaric acid, fumaryl coenzyme A, N-acylated cysteamine, S-acylated cysteamine, N-acylated cysteine (if R ₂ is C0 ₂ R ₅ or C(=0)NR ₅ R ₆ ), S- acylated cysteine (if R ₂ is CO2R5 or C(=0)NR ₅ R ₆ ), cysteamine (if R-i and R ₂ are both H), cysteine or canonical forms of the same ((if R ₂ is C0 ₂ R ₅ or C(=0)NR ₅ R ₆ )). They may do so as follows.

When a thiol group is released, this is regarded as especially advantageous as the thiol group has reductive properties. Many diseases have an unwanted oxidative stress component, which may lead to damage to cell structure and cell function. Accordingly, release of a component, which can act as an anti-oxidant and scavenge free radicals or reduce oxygen-reactive species is expected to give extra benefit in medical or cosmetic use.

A compound of the invention may be a thioester. For such compounds is S, X ₂ is NH, R-i is H and R ₂ is H or C0 ₂ R ₅ or C(=0)NR ₅ R ₆ .

A compound of the invention may be an amide. For such compounds X-i is NH, X ₂ is S, R-i is H or C0 ₂ R ₅ or C(=0)NR ₅ R ₆ and R ₂ is H. As seen from the experiments reported in the experimental section both amides and thioesters according to the invention have improved properties compared with the known dimethyl fumarate and monomethylfumarate.

In some compounds of the invention, at least one of R-i and R ₂ is H.

In some compounds of interest R ₄ is methyl or ethyl.

R ₄ may be methyl, ethyl or propyl. R ₅ and R ₆ may be the same or different and in some compounds of interest they may be methyl or ethyl.

As seen from the examples herein the invention specifically provides a compound selected from

(compound 1 )

(compound 2) (compound 3)

(compound 5)

The present invention also provides methods for preparing compounds of the invention. The compounds have improved properties for use in medicine. The compounds of the invention are also useful as research tools for mitochondrial in vitro investigations using intact cells or for in vivo animal use.

Indications for which the disclosed compounds of the invention may be therapeutically effective include multiple sclerosis, non-alcoholic steatohepatitis (NASH), inflammatory bowel disease, asthma, chronic obstructive pulmonary disease, and arthritis. Notably, the compounds of the invention are useful in the prevention or treatment of multiple sclerosis or psoriasis

Methods of treating a disease in a patient provided by the present disclosure comprise administering to a patient in need of such treatment a suitable dose of one or more compounds of the invention. An appropriate dose of a compound of the invention may be determined based on several factors, including, for example, the body weight and/or condition of the patient being treated, the severity of the disease being treated, the incidence and/or severity of side effects, the manner of administration, and the judgment of the prescribing physician. Appropriate dose ranges may be determined by methods known to those skilled in the art.

The compounds of the invention disclosed herein may be used to treat diseases, disorders, conditions, and symptoms of any of the foregoing for which FAEs, such as dimethyl fumarate or monomethyl fumarate are known to provide or is later found to provide therapeutic benefit. FAEs are effective in treating psoriasis, multiple sclerosis, inflammatory bowel disease, asthma, chronic obstructive pulmonary disease, and arthritis. Hence, the compounds of the invention disclosed herein may be used to treat any of the foregoing diseases and disorders. Thus, a therapeutically effective amount of compounds of the invention may be administered as a preventative measure to a patient having a predisposition for and/or history of immunological, autoimmune, and/or inflammatory diseases including multiple sclerosis, psoriasis, non-alcoholic

steatohepatitis, non-alcoholic fatty liver disease, asthma and chronic obstructive pulmonary diseases, neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, inflammatory bowel diseases such as Crohn's disease and ulcerative colitis and cancer.

In addition, compared with dimethylfumarate or monomethylfumarate the compounds are contemplated to show improved properties for treatment of these and related diseases, including better cell permeability, longer plasma half-life, reduced toxicity, increased potency, and improved formulation (due to improved properties including increased solubility). In some cases, the compounds are also more orally bioavailable.

Thus the advantageous properties of the compound of the invention may include one or more of the following:

-Increased cell permeability

-Reduced efflux

-Longer half-life in plasma

-Reduced toxicity

-Improved formulation

-Increased solubility -Increased oral bioavailability

-Increased potency

In the following is given an overview of diseases of particular interest regarding the present invention.

Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system thought to be caused by autoimmune attack of axonal myelin sheets of the central nervous system. Demyelination leads to a reduction in conduction and disease with destruction of axons and irreversible neuronal cell death. The symptoms of MS are varied with each patient exhibiting a pattern of motor and sensory disturbances. MS is typified pathologically by multiple inflammatory foci, plaques of demyelination, gliosis, and axonal pathology within the brain and spinal cord, all of which contribute to the clinical manifestations of neurological disability (see e.g., Wingerchuk, Lab Invest 2001 , 81 , 263-281 ; and Virley, NeuroRx 2005, 2(4), 638-649).

Although the events that precipitate MS are not fully understood, evidence suggests an autoimmune aetiology with environmental and genetic factors. Functional impairment is expressed as paralysis and sensory disturbances, spasticity, tremor, loss of

coordination, and visual impairment. The clinical course of MS can vary between individuals, but can be categorized in three forms: relapsing-remitting, secondary progressive, and primary progressive. Assessment of MS treatment efficacy in clinical trials can be accomplished using tools such as the Expanded Disability Status Scale and the MS Functional as well as magnetic resonance imaging lesion load, biomarkers, and self-reported quality of life. Animal models of MS shown to be useful to identify and validate potential therapeutics include experimental autoimmune/allergic encephalomyelitis (EAE) rodent models that simulate the clinical and pathological manifestations of MS and nonhuman primate EAE models.

Non-alcoholic Steatohepatitis (NASH) Non-alcoholic fatty liver disease (NAFLD) is the most common cause of referral to liver clinics, and its progressive form, non-alcoholic steatohepatitis (NASH), can lead to cirrhosis and end-stage liver disease. Nrf2 activation has been proposed as a target for treatment of NASH (Bataille et al. Clin Pharmacol Ther. 2012 Sep; 92(3): 340-348.; Chambel et al., Biomed Res Int. 2015; 2015: 597134., Musso et al., Nature Reviews Drug Discovery 15, 249-274 (2016)) . In addition, growing evidence indicates that NF- KB activation contributes to the pathogenesis of NASH, suggesting N FKB inhibition as a target (Locatelli et al., Clinical Science Feb 01 , 2013, 124 (4) 279-287). Psoriasis

Psoriasis is characterized by hyperkeratosis and thickening of the epidermis as well as increased vascularity and infiltration of inflammatory cells in the dermis. Psoriasis vulgaris manifests as silvery, scaly, erythematous plaques on typically the scalp, elbows, knees, and buttocks. Guttate psoriasis occurs as tear-drop size lesions.

Fumaric acid esters are used clinically in the treatment of psoriasis (Mrowietz and

Asadullah, Trends Mol Med 2005, 1 1 (1 ), 43-48; and Mrowietz et al., Br J Dermatology 1999, 141 , 424- 429). Efficacy of compounds of the invention for treating psoriasis can be determined using animal models and in clinical trials. Inflammatory Arthritis

Inflammatory arthritis includes diseases such as rheumatoid arthritis, juvenile rheumatoid arthritis (juvenile idiopathic arthritis), psoriatic arthritis, and ankylosing spondylitis, each of which produce joint inflammation. The pathogenesis of immune- mediated inflammatory diseases including inflammatory arthritis is believed to involve N K-KB signalling pathways (Tracey et al., Pharmacology & Therapeutics 2008, 1 17, 244-279). DMF has been shown potential to treat inflammatory diseases including inflammatory arthritis, which are believed to involve N K-KB signalling and therefore may be useful in treating inflammatory arthritis (Lowe et al., J Immunology 2002, 168, 4781- 4787). The efficacy of compounds of the invention for treating inflammatory arthritis can be determined using animal models and in clinical trials.

Inflammatory Bowel Disease Inflammatory bowel disease (IBD) describes a group of inflammatory conditions including Crohn's disease and ulcerative colitis. Crohn's disease, which is

characterized by regions of inflammation affecting any part of the gastrointestinal tract. Symptoms include abdominal pain, diarrhoea, constipation, vomiting and weight loss or gain. Crohn's disease can also cause skin rashes, arthritis, and eye inflammation.

Ulcerative colitis is characterized by ulcers or open sores in the large intestine or colon. Other types of intestinal bowel disease include collagenous colitis, lymphocytic colitis, ischaemic colitis, diversion colitis, Behcet's colitis or disease and indeterminate colitis. FAEs are inhibitors of NF-κΒ activation and therefore may be useful in treating inflammatory diseases such as Crohn's disease and ulcerative colitis (Atreya et al., J Intern Med 2008, 263(6), 59106).

The efficacy of compounds of the invention for treating inflammatory bowel disease can be evaluated using animal models and in clinical trials. Useful animal models of inflammatory bowel disease are known.

Asthma

Asthma is a reversible airway obstruction in which the airway occasionally constricts, becomes inflamed, and is lined with an excessive amount of mucus. Symptoms of asthma include dyspnoea, wheezing, chest tightness, and cough. Asthma episodes may be induced by airborne allergens, food allergies, medications, inhaled irritants, physical exercise, respiratory infection, psychological stress, hormonal changes, cold weather, or other factors.

As an inhibitor of NF-κΒ activation and as seen in animal studies (Joshi et al., US 2007/0027076) FAEs and compounds of similar mechanism, such as FAMs may be useful in treating pulmonary diseases such as asthma and chronic obstructive pulmonary disorder.

The efficacy of compounds of the invention for treating asthma can be assessed using animal models and in clinical trials.

Cancer DMF inhibited the proliferation of A375 and M24met cell lines and reduced melanoma growth and metastasis in experimental melanoma mouse models (Cancer Res (2006) 66:1 1888-96). DMF also arrested the cell cycle at the G2-M boundary and was pro- apoptotic, inhibiting tumour cell growth (Cell Mol Immunol (2016) 13:57-64). DMF was also seen to inhibit the N FKB pathway in breast cancer cells (Kastrati et al., J Biol

Chem. 2016 Feb 12;291 (7):3639-47). The cancer types against which DMF has shown efficacy include: breast cancer, cervical cancer (Han et al., In Vitro Cell Dev Biol Anim. 2016 Aug 5), t-cell lymphoma (Blood. 2016 Aug 1 1 ;128(6):805-15), brain cancer including glioblastoma, ovarian cancer (Tavallai et al., Oncotarget. 2016 Apr

5;7(14):17290-300), colon cancer (Xie et al., Br J Pharmacol. 2015 Aug;172(15):3929- 43), and melanoma (Yamazoe et al., Cell Biol Int. 2009 Oct;33(10):1087-94.) The efficacy of compounds of the invention for treating cancer can be assessed using in vitro cancer cell line panels, animal models such as xenograft models and in clinical trials.

Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by limitation of airflow in the airway that is not fully reversible, and includes conditions such as chronic bronchitis, emphysema, as well as other lung disorders such as asbestosis, pneumoconiosis, and pulmonary neoplasms (Barnes, Pharmacological Reviews 2004, 56(4), 515-548). The airflow limitation is often progressive and linked with an abnormal inflammatory response of the lungs to noxious particles and gases. COPD is characterized by a shortness of breath and a persistent cough with sputum production. COPD is often caused by tobacco smoking, although other causative agents include coal dust, asbestos, urban pollution or solvents. COPD encompasses chronic obstructive bronchiolitis with fibrosis and obstruction of small airways, and emphysema with enlargement of airspaces and destruction of lung parenchyma, loss of lung elasticity, and closure of small airways. The efficacy of compounds of the invention for treating chronic obstructive pulmonary disease may be assessed using animal models of chronic obstructive pulmonary disease and in clinical studies.

Parkinson's Disease Neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease and amyoptrophic lateral sclerosis are characterized by progressive dysfunction and neuronal death. NF-κΒ inhibition has been proposed as a therapeutic target for neurodegenerative diseases (Camandola and Mattson, Expert Opin Ther Targets 2007, 1 1 (2), 123-32).

Parkinson's disease is a progressive degenerative disorder of the nervous system characterized by resting tremor, slowness of voluntary movements, and increased muscle tone (rigidity). In Parkinson's disease, nerve cells in the basal ganglia degenerate, and thereby reduce the production of dopamine and the number of connections between nerve cells in the basal ganglia. The basal ganglia are then unable to properly control smooth muscle movements and coordinate changes in posture as normal, leading to tremor, incoordination, and slowed, reduced movement (Blandini, et al., Mol. Neurobiol. 1996, 12, 73-94). The efficacy of compounds of the invention for treating Parkinson's disease may be assessed using animal and human models of Parkinson's disease and in clinical studies.

Alzheimer's Disease

Alzheimer's disease is a progressive loss of mental function characterized by degeneration of brain tissue, loss of nerve cells and the development of senile plaques and neurofibrillary tangles. Parts of the brain degenerate, destroying nerve cells and reducing the responsiveness of neurons to neurotransmitters. Abnormalities in brain tissue consist of senile or neuritic plaques, containing amyloid and neurofibrillary tangles.

The efficacy of compounds of the invention for treating Alzheimer's disease may be assessed using animal and human models of Alzheimer's disease and in clinical studies.

Huntington's Disease Huntington's disease is an autosomal dominant neurodegenerative disorder in which cell death occurs in the neostriatum and cortex (Martin, N Engl J Med 1999, 340, 1970- 80). Onset usually occurs during the fourth or fifth decade of life in the 40s or 50s, with a mean survival at age of onset of 14 to 20 years. Huntington's disease is universally fatal, and there is no effective treatment. Symptoms include a characteristic movement disorder (Huntington's chorea), cognitive dysfunction, and psychiatric symptoms. The disease is caused by a mutation encoding an abnormal expansion of CAG-encoded polyglutamine repeats in the protein, huntingtin. The efficacy of compounds of the invention for treating Huntington's disease may be assessed using animal and human models of Huntington's disease and in clinical studies.

Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the progressive and specific loss of motor neurons in the brain, brain stem, and spinal cord (Rowland and Schneider, N Engl J Med 2001 , 344, 1688-1700). ALS begins with weakness, often in the hands and less frequently in the feet that generally progresses up an arm or leg. Over time, weakness increases and spasticity develops characterized by muscle twitching and tightening, followed by muscle spasms and possibly tremors. The average age of onset is 55 years, and the average life expectancy after the clinical onset is 4 years.

The efficacy of compounds of the invention for treating ALS may be assessed using animal and human models of ALS and in clinical studies.

Friedreich's Ataxia

Friedreich's Ataxia is an ultimately lethal inherited neurodegenerative disease. DMF has shown potential to treat Friedreich's ataxia (Hayashi et al., PLoS One. 2016 Apr 14;1 1 (4):e0153574).

The efficacy of compounds of the invention for treating Friedreich's Ataxia may be assessed using in vitro and in vivo models of Friedreich's Ataxia and in clinical studies.

Other Diseases Other diseases, disorders and conditions for which compounds of the invention may be useful in treating include: acute haemorrhagic leucoencephalomyelitis, Hurst's disease, encephalomyelitis (e.g., acute disseminated encephalomyelitis), optic neuritis, spinal cord lesions, acute necrotizing myelitis, transverse myelitis, chronic progressive myelopathy, progressive multifocal leukoenceplialopathy (PML), radiation myelopathy, HTLV-1 associated myelopathy, monophasic isolated demyelination, central pontine myelinolysis, leueodystrophy (e.g., adrenoleucodystrophy, metachromatic

leueodystrophy, Krabbe's disease, Canavan's disease, Alexander's disease,

Pelizaeus-Merbacher disease, vanishing white matter disease, oculodentodigital syndrome), inflammatory demyelinising polyneuropathy (e.g., chronic inflammatory demyelinating polyneuritis (CIDP), and acute inflammatory demyelinating

polyneuropathy (AIDP)), Guillain-Barre syndrome (GBS), polyneuritis, myasthenia gravis (MG), Eaton Lambert Syndrome (ELS), and encephalomyelitis, Idiopathic Pulmonary Fibrosis (IPF), Scleroderma lung disease, Acute Lung Injury (ALI)/Acute respiratory Distress (ARDS), Chronic Asthma, Radiation-Induced Fibrosis Sarcoidosis, Pulmonary Hypertension, Bronchopulmonary Dysplasia (BPD), Lung Transplant Rejection, Pulmonary GVHD Complications, Interstitial pneumonia Syndrome (IPS) in transplant recipients, COPD, Silicosis, Asbestosis, Sarcoidosis (lung), Primary sclerosing cholangitis (PSC), Alcohol-induced hepatic fibrosis, autoimmune haemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, autoimmune carditis, Chronic viral hepatitis (HepB/C), Primary biliary cirrhosis (PBC), Liver transplant rejection, Hepatic complications of GVHD, Veno-occlusive disease in transplant recipients, Focal Segmental Glomerular Sclerosis (FSGS), Diabetic nephropathy, IgA nephropathy, Scleroderma, Renal complications of GVHD (AKI delayed graft function), Acute renal failure post CABG (AKI post CABG), Lupus nephritis, Hypertension- induced Renal Fibrosis, HIV-associated nephropathy, Peritoneal dialysis-induced peritoneal fibrosis, Retroperitoneal fibrosis, Idiopathic Glomerulosclerosis, Kidney transplant rejection, Alport syndrome, Restenosis, Subarachnoid haemorrhage (SAH), Heart transplant rejection, Stroke, Cosmetic surgery, Chronic wounds, Burns, Surgical adhesions, Keloids, Donor graft re-epithelialization, Myelofibrosis, Corneal transplant, LASIX, Trabeculectomy, Systemic sclerosis, Radiation induced fibrosis, Peripatellar Fibrosis, and Dupuytren's Contractures, inflammatory bowel disease, Crohn's disease, lupus (e.g., Neuropsychiatric lupus), systemic Lupus erythematodes (SLE), asthma, Leber's disease, Devic's disease (NMO), Friedrich's Ataxia, mitochondrial Central Nervous System diseases, scleroderma, uveitis, anti-phospholipid antibody syndrome, polyarthritis (e.g., rheumatoid arthritis), polyarticular juvenile idiopathic arthritis, sickle cell disease, ankylosing spondylitis, myositis, atherosclerosis, diabetic peripheral neuropathy, head injury, stroke, HIV-dementia, myocardial infarction, angina pectoris, cardiac insufficiency, psoriasis, psoriatic arthritis, Sjogren's syndrome, diabetes (e.g., type 1 diabetes, diabetes meilitus type II, juvenile-onset diabetes), blistering skin diseases, sarcoidosis, osteoarthritis, ulcerative colitis, vasculitis, lung fibrosis, idiopathic pulmonary fibrosis (IPF), liver fibrosis, kidney fibrosis, acute kidney injury, chronic kidney disease - diabetic nephrophathy, graft- versus-host reactions,

Hashimoto's thyroiditis, Hashimoto's disease, Grave's disease, pernicious anaemia, acute hepatitis, toxic hepatitis, alcohol-induced hepatitis, viral hepatitis, jaundice, liver insufficiency, and cy tome gal oviral hepatitis), neurodermatitis, retinopathia

pigmentosa, forms of mitochondrial encephalomyopathy, osteochondritis syphilitica (Wegener's disease), cutis marmorata (livedo reticularis), Behcet disease, panarteritis, osteoarthritis, gout, artenosclerosis, Reiter's disease, pulmonary granulomatosis, types of encephalitis, endotoxic shock (septic-toxic shock), sepsis, pneumonia, anorexia nervosa, Rennert T-iymphomatosis, mesangial nephritis, post-angioplastic restenosis, reperfusion syndrome, cytomegaloviral retinopathy, adenoviral diseases (e.g., adenoviral colds, adenoviral pharyngoconjunctlval fever and adenoviral ophthalmia), AIDS, post-herpetic or post-zoster neuralgia, mononeuropathia multiplex,

mucoviscidosis, Bechterew's disease, Barett oesophagus, Epstein- Barr virus (EVB) infection, cardiac remodeling, interstitial cystitis, human tumour radiosensitisation, multi -resistance of malignant cells to chemotherapeutic agents (multidrug resistance in chemotherapy), granuloma annulare and cancers (including breast, colon, ovarian, cervical, brain cancers, melanoma and t-cell lymphoma), chronic obstructive pulmonary diseases, PDGF induced thymidine uptake of bronchial smooth muscle cells, bronchial smooth muscle cell proliferation, Adrenal Leukodystrophy (ALD), Alcoholism, Alper's disease, Ataxia telangiectasia, Batten disease (also known as Spielmeyer-Vogt- Sjogren-Batten disease), Bovine spongiform encephalopathy (BSE), Cerebral palsy, Cockayne syndrome, Corticobasal degeneration, Creutzfeldt- Jakob disease, Chagas disease, Charcott-Marie-Tooth Disease, Familial Fatal Insomnia, Frontotemporal lobar degeneration, Kennedy's disease, Lewy body dementia, Neurohorreliosis,

Goodpasture's syndrome, Machado- Joseph disease (Spinocerebellar ataxia type 3), Multiple System Atrophy, Narcolepsy, Niemann Pick disease, Pick's disease, Primary lateral sclerosis, Prion diseases, Progressive Supranuclear Palsy, Refsum's disease, Sandhoff disease, Schilder's disease, Subacute combined degeneration of spinal cord secondary to Pernicious Anaemia, Spinocerebellar ataxia, Spinal muscular atrophy, Steele-Richardson-Olszewski disease, Tabes dorsalis, Toxic encephalopathy, mitochondrial Central Nervous System diseases, MELAS (Mitochondrial

Encephalomyopathy; Lactic Acidosis; Stroke), MERRF (Myoclonic Epilepsy; Ragged Red Fibers), PEO (Progressive External Opthalmoplegia), Leigh's Syndrome, MNGIE (Myopathy and external ophthalmoplegia; Neuropathy; Gastro-lntestinal;

Encephalopathy), Kearns-Sayre Syndrome (KSS), NARP, Hereditary Spastic

Paraparesis, Mitochondrial myopathy, optic neuritis, progressive multifocal

leucoencephalopathy (PML), Pyoderma Gangrenosum, Erosive Pustular Dermatosis of the Scalp, Sweet's Syndrome, Bowel-associated Dermatosis- arthritis Syndrome, Pustular Psoriasis, Acute Generalized Exanthematous Pustulosis, Keratoderma Blenorrhagicum, Sneddon- Wilkinson Disease, Amicrobial Pustulosis of the Folds, Infantile Acropustulosis, Transient Neonatal Pustulosis, Neutrophilic Eccrine

Hidradenitis, Rheumatoid Neutrophilic Dermatitis, Neutrophilic Urticaria, Still's Disease, Erythema Marginatum, Unclassified Periodic Fever Syndromes/Autoinflammatory Syndromes, Bullous Systemic Lupus Erythematosus, Neutrophilic Dermatosis of the Dorsal Hands (Pustular Vasculitis), anaphylaxis, allergic rhinitis, allergic asthma, severe asphyxic episodes of asthma, acute lung injury, Acute Respiratory Distress Syndrome, ischemia reperfusion injury, Krabbe Disease, Zellweger's syndrome, eczema, Wegener's granulomatosis, septicemia with multiorgan failure, inderteminate colitis, sickle cell crisis, Addison's disease or acute chest syndrome.

General Chemistry Methods

The skilled person will recognise that the compounds of the invention may be prepared, in known manner, in a variety of ways. The routes below are merely illustrative of some methods that can be employed for the synthesis of compounds of formula (I).

Compounds of the invention may be made by starting with a suitable carboxylic acid- based metabolite such as fumaric acid.

Compounds of the invention may be synthesised by the formation of a thioester or amide bond. The substrate for the bond formation is fumarate, optionally with one of the carboxylic acids already derivatised as desired for the target compound or protected with a protecting group. Protecting groups include but are not limited to benzyl and tert-butyl. Other protecting groups for carbonyls and their removal are detailed in 'Greene's Protective Groups in Organic Synthesis' (Wuts and Greene, Wiley, 2006). Protecting groups may be removed by methods known to one skilled in the art including hydrogenation in the presence of a heterogenous catalyst for benzyl esters and treatment with organic or mineral acids, preferably trifluoroacetic acid or dilute HCI, for tert-butyl esters.

To make the thioester or amide bond one of the carboxylic acid groups on fumarate may require activation. Activating groups includes but is not limited to mixed anhydrides and acyl chlorides. Acid chlorides may be made by reaction of the carboxylic acid with a compound such as oxalyl chloride or thionyl chloride, though it will be obvious to one skilled in the art that other reagents may be used for this transformation. Where mixtures are formed then the compounds of the invention may need to be separated. One method for separating the compounds is column chromatography.

Pharmaceutical compositions comprising a compound of the invention

The present invention also provides a pharmaceutical composition comprising the compound of the invention together with one or more pharmaceutically acceptable diluents or carriers.

The compound of the invention or a formulation thereof may be administered by any conventional method for example but without limitation it may be administered parenterally, orally, topically (including buccal, sublingual or transdermal), via a medical device (e.g. a stent), by inhalation or via injection (subcutaneous or intramuscular). The treatment may consist of a single dose or a plurality of doses over a period of time.

The treatment may be by administration once daily, twice daily, three times daily, four times daily etc. The treatment may also be by continuous administration such as e.g. administration intravenous by drop. Whilst it is possible for the compound of the invention to be administered alone, it is preferable to present it as a pharmaceutical formulation, together with one or more acceptable carriers. The carrier(s) must be "acceptable" in the sense of being compatible with the compound of the invention and not deleterious to the recipients thereof. Examples of suitable carriers are described in more detail below.

The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Such methods include the step of bringing into association the active ingredient (compound of the invention) with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product. The compound of the invention will normally be administered orally, intravenously or by any parenteral route, in the form of a pharmaceutical formulation comprising the active ingredient, optionally in the form of a non-toxic organic, or inorganic, acid, or base, addition salt, in a pharmaceutically acceptable dosage form. Depending upon the disorder and patient to be treated, as well as the route of administration, the

compositions may be administered at varying doses.

The pharmaceutical compositions must be stable under the conditions of manufacture and storage; thus, preferably should be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), vegetable oils, and suitable mixtures thereof, or it may be a solid material eg for manufacturing of solid dosage forms.

For example, the compound of the invention can also be administered orally, buccally or sublingually in the form of tablets, capsules, ovules, elixirs, solutions or suspensions, which may contain flavouring or colouring agents, for immediate-, delayed- or controlled-release applications.

Formulations in accordance with the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets, each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil- in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste. Solutions, emulsions or suspensions of the compound of the invention suitable for oral administration may also contain excipients e.g. Ν,Ν-dimethylacetamide, dispersants e.g. polysorbate 80, surfactants, and solubilisers, e.g. polyethylene glycol, Phosal 50 PG (which consists of phosphatidylcholine, soya-fatty acids, ethanol,

mono/diglycerides, propylene glycol and ascorbyl palmitate). The formulations according to present invention may also be in the form of emulsions, wherein a compound according to Formula (I) may be present in an aqueous oil emulsion. The oil may be any oil-like substance such as e.g. soy bean oil or safflower oil, medium chain triglycieride (MCT-oil) such as e.g. coconut oil, palm oil etc or combinations thereof. Tablets may contain excipients such as microcrystalline cellulose, lactose (e.g. lactose monohydrate or lactose anyhydrous), sodium citrate, calcium carbonate, dibasic calcium phosphate and glycine, butylated hydroxytoluene (E321 ), crospovidone, hypromellose, disintegrants such as starch (preferably corn, potato or tapioca starch), sodium starch glycollate, croscarmellose sodium, and certain complex silicates, and granulation binders such as polyvinylpyrrolidone, hydroxypropylmethylcellulose

(HPMC), hydroxy-propylcellulose (HPC), macrogol 8000, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, stearic acid, glyceryl behenate and talc may be included. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g. povidone, gelatin, hydroxypropylmethyl cellulose), lubricant, inert diluent, preservative, disintegrant (e.g. sodium starch glycolate, cross-linked povidone, cross-linked sodium carboxymethyl cellulose), surface-active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethylcellulose in varying proportions to provide desired release profile. Solid compositions of a similar type may also be employed as fillers in gelatin capsules. Preferred excipients in this regard include lactose, starch, a cellulose, milk sugar or high molecular weight polyethylene glycols. For aqueous suspensions and/or elixirs, the compounds of the invention may be combined with various sweetening or flavouring agents, colouring matter or dyes, with emulsifying and/or suspending agents and with diluents such as water, ethanol, propylene glycol and glycerin, and

combinations thereof.

Formulations suitable for administration in the mouth include lozenges comprising the active ingredient in a flavoured basis, usually sucrose and acacia or tragacanth;

pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouth-washes comprising the active ingredient in a suitable liquid carrier. Pharmaceutical compositions adapted for topical administration may be formulated as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, impregnated dressings, sprays, aerosols or oils, transdermal devices, dusting powders, and the like. These compositions may be prepared via conventional methods containing the active agent. Thus, they may also comprise compatible conventional carriers and additives, such as preservatives, solvents to assist drug penetration, emollient in creams or ointments and ethanol or oleyl alcohol for lotions. Such carriers may be present as from about 1 % up to about 98% of the composition. More usually they will form up to about 80% of the composition. As an illustration only, a cream or ointment is prepared by mixing sufficient quantities of hydrophilic material and water, containing from about 5- 10% by weight of the compound, in sufficient quantities to produce a cream or ointment having the desired consistency.

Pharmaceutical compositions adapted for transdermal administration may be presented as discrete patches intended to remain in intimate contact with the epidermis of the recipient for a prolonged period of time. For example, the active agent may be delivered from the patch by iontophoresis.

For applications to external tissues, for example the mouth and skin, the compositions are preferably applied as a topical ointment or cream. When formulated in an ointment, the active agent may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active agent may be formulated in a cream with an oil-in-water cream base or a water-in-oil base. For parenteral administration, fluid unit dosage forms are prepared utilizing the active ingredient and a sterile vehicle, for example but without limitation water, alcohols, polyols, glycerine and vegetable oils, water being preferred. The active ingredient, depending on the vehicle and concentration used, can be either colloidal, suspended or dissolved in the vehicle. In preparing solutions the active ingredient can be dissolved in water for injection and filter sterilised before filling into a suitable vial or ampoule and sealing.

Advantageously, agents such as local anaesthetics, preservatives and buffering agents can be dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. The dry lyophilized powder is then sealed in the vial and an accompanying vial of water for injection may be supplied to reconstitute the liquid prior to use.

Pharmaceutical compositions of the present invention suitable for injectable use include sterile aqueous solutions or dispersions. Furthermore, the compositions can be in the form of sterile powders for the extemporaneous preparation of such sterile injectable solutions or dispersions. In all cases, the final injectable form must be sterile and must be effectively fluid for easy syringability. Parenteral suspensions are prepared in substantially the same manner as solutions, except that the active ingredient is suspended in the vehicle instead of being dissolved and sterilization cannot be accomplished by filtration. The active ingredient can be sterilised by exposure to ethylene oxide before suspending in the sterile vehicle.

Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the active ingredient.

It should be understood that, in addition to the ingredients particularly mentioned above the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavouring agents. A person skilled in the art will know how to choose a suitable formulation and how to prepare it (see eg Remington's Pharmaceutical Sciences 18 Ed. or later). A person skilled in the art will also know how to choose a suitable administration route and dosage.

It will be recognized by one of skill in the art that the optimal quantity and spacing of individual dosages of a compound of the invention will be determined by the nature and extent of the condition being treated, the form, route and site of administration, and the age and condition of the particular subject being treated, and that a physician will ultimately determine appropriate dosages to be used. This dosage may be repeated as often as appropriate. If side effects develop the amount and/or frequency of the dosage can be altered or reduced, in accordance with normal clinical practice.

All % values mentioned herein are % w/w unless the context requires otherwise.

Compounds of the invention all may be transformed in a biological matrix to liberate monomethylfumarate (MMF), MMFcoenzyme A, fumaric acid, fumaryl coenzyme A, N- acylated cysteamine, S-acylated cysteamine, N-acylated cysteine, S-acylated cysteine, cysteamine, cysteine or canonical forms of the same. They may do so as follows.

When a thiol group is released, this is regarded as especially advantageous as the thiol group has reductive properties. Many diseases have an unwanted oxidative stress component, which may lead to damage to cell structure and cell function. Accordingly, release of a component which can act as an anti-oxidant and scavenge free radicals or reduce oxygen-reactive species is expected to give extra benefit in medical or cosmetic use.

Other aspects of the invention

The present invention also provides a combination (for example for the treatment of mitochondrial dysfunction) of a compound of formula (I) or formula (IA) or a

pharmaceutically acceptable form thereof as hereinbefore defined and one or more agents independently selected from:

• Quinone derivatives, e.g. Ubiquinone, Idebenone, MitoQ

• Vitamins e.g. Tocopherols, Tocotrienols and Trolox (Vitamin E), Ascorbate (C), Thiamine (B1 ), Riboflavin (B2), Nicotinamide (B3), Menadione (K3),

• Antioxidants in addition to vitamins e.g. TPP-compounds (MitoQ), Sk- compounds, Epicatechin, Catechin, Lipoic acid, Uric acid, Melatonin

• Dichloroacetate • Methylene blue

• l-arginine

• Szeto-Schiller peptides

• Creatine

• Benzodiazepines

• Modulators of PGC-1 a

• Ketogenic diet

Combination of drugs and compounds of the invention

It should be noted that compounds of the invention may be combined with other drugs to improve the efficacy of the therapeutic treatment. In particular, compounds of the invention may be combined with standard of care treatments or treatments in development for the diseases described in this application. Definitions

The articles "a" and "an" are used herein to refer to one or to more than one (i.e. at least one) of the grammatical objects of the article. By way of example "an analogue" means one analogue or more than one analogue. As used herein the terms "permeable fumarate acyl mercaptoethylamines", "FAMs", "cell permeable carboxylic acid-based metabolites", "compound(s) of the invention", "cell-permeable metabolite derivatives" and "cell permeable precursors of metabolites" are used interchangeably and refer to compounds of formula (I). As used herein, the term "bioavailability" refers to the degree to which or rate at which a drug or other substance is absorbed or becomes available at the site of biological activity after administration. This property is dependent upon a number of factors including the solubility of the compound, rate of absorption in the gut, the extent of protein binding and metabolism etc. Various tests for bioavailability that would be familiar to a person of skill in the art are described herein (see also Trepanier et al, 1998, Gallant-Haidner ef al, 2000). The pharmaceutically acceptable salts of the compound of the invention include conventional salts formed from pharmaceutically acceptable inorganic or organic acids or bases as well as quaternary ammonium acid addition salts. More specific examples of suitable acid salts include hydrochloric, hydrobromic, sulfuric, phosphoric, nitric, perchloric, fumaric, acetic, propionic, succinic, glycolic, formic, lactic, maleic, tartaric, citric, palmoic, malonic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, fumaric, toluenesulfonic, methanesulfonic, naphthalene-2-sulfonic, benzenesulfonic hydroxynaphthoic, hydroiodic, malic, steroic, tannic and the like. Other acids such as oxalic, while not in themselves pharmaceutically acceptable, may be useful in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable salts. More specific examples of suitable basic salts include sodium, lithium, potassium, magnesium, aluminium, calcium, zinc, Ν,Ν'- dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, N- methylglucamine and procaine salts.

As used herein the term "alkyl" refers to any straight or branched chain composed of only sp3 carbon atoms, fully saturated with hydrogen atoms such as e.g. -C _n H _2n +i for straight chain alkyls, wherein n can be in the range of 1 and 10 such as e.g. methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, isopentyl, hexyl, isohexyl, heptyl, octyl, nonyl or decyl. The alkyl as used herein may be further substituted.

As used herein the term "cycloalkyl" refers to a cyclic/ring structured carbon chains having the general formula of -C _n H _2n -i where n is between 3-10, such as e.g.

cyclopropyl, cyclobytyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl,

bicycle[3.2.1]octyl, spiro[4,5]decyl, norpinyl, norbonyl, norcapryl, adamantly and the like.

As used herein, the term "alkene" refers to a straight or branched chain composed of carbon and hydrogen atoms wherein at least two carbon atoms are connected by a double bond such as e.g. C _2- io alkenyl unsaturated hydrocarbon chain having from two to ten carbon atoms and at least one double bond. C _2- 6 alkenyl groups include, but are not limited to, vinyl, 1-propenyl, allyl, iso-propenyl, n-butenyl, n-pentenyl, n-hexenyl and the like. The term "Ο _1Ί0 alkoxy" in the present context designates a group -0-C-^ ₆ alkyl used alone or in combination, wherein C _r w alkyl is as defined above. Examples of linear alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy and hexoxy. Examples of branched alkoxy are iso-propoxy, sec-butoxy, tert-butoxy, iso-pentoxy and iso-hexoxy. Examples of cyclic alkoxy are cyclopropyloxy, cyclobutyloxy, cyclopentyloxy and cyclohexyloxy.

The term "C ₃ - ₇ heterocycloalkyl" as used herein denotes a radical of a totally saturated heterocycle like a cyclic hydrocarbon containing one or more heteroatoms selected from nitrogen, oxygen and sulphur independently in the cycle. Examples of

heterocycles include, but are not limited to, pyrrolidine (1 -pyrrolidine, 2-pyrrolidine, 3- pyrrolidine, 4-pyrrolidine, 5-pyrrolidine), pyrazolidine (1-pyrazolidine, 2-pyrazolidine, 3- pyrazolidine, 4-pyrazolidine, 5-pyrazolidine), imidazolidine (1 -imidazolidine, 2- imidazolidine, 3-imidazolidine, 4-imidazolidine, 5-imidazolidine), thiazolidine (2- thiazolidine, 3-thiazolidine, 4-thiazolidine, 5-thiazolidine), piperidine (1-piperidine, 2- piperidine, 3-piperidine, 4-piperidine, 5-piperidine, 6-piperidine), piperazine (1 - piperazine, 2-piperazine, 3-piperazine, 4-piperazine, 5-piperazine, 6-piperazine), morpholine (2-morpholine, 3-morpholine, 4-morpholine, 5-morpholine, 6-morpholine), thiomorpholine (2-thiomorpholine, 3-thiomorpholine, 4-thiomorpholine, 5- thiomorpholine, 6- thiomorpholine), 1 ,2-oxathiolane (3-(1 ,2-oxathiolane), 4-(1 ,2- oxathiolane), 5-(1 ,2-oxathiolane)), 1 ,3-dioxolane (2-(1 ,3-dioxolane), 3-(1 ,3- dioxolane), 4-(1 ,3-dioxolane)), tetrahydropyrane (2- tetrahydropyrane, 3- tetrahydropyrane, 4- tetrahydropyrane, 5-tetrahydropyrane, 6- tetrahydropyrane), hexahydropyradizine, (1 -(hexahydropyradizine), 2-(hexahydropyradizine), 3- (hexahydropyradizine), 4-(hexahydropyradizine), 5-(hexahydropyradizine), 6- (hexahydropyradizine)).

The term "C-i.-ioalkyl-Cs.-iocycloalkyl" as used herein refers to a cycloalkyl group as defined above attached through an alkyl group as defined above having the indicated number of carbon atoms.

The term "C _1-10 alkyl-C _3-7 heterocycloalkyl" as used herein refers to a heterocycloalkyl group as defined above attached through an alkyl group as defined above having the indicated number of carbon atoms. The term "aryl" as used herein is intended to include carbocyclic aromatic ring systems. Aryl is also intended to include the partially hydrogenated derivatives of the carbocyclic systems enumerated below. The term "heteroaryl" as used herein includes heterocyclic unsaturated ring systems containing one or more heteroatoms selected among nitrogen, oxygen and sulphur, such as furyl, thienyl, pyrrolyl, and is also intended to include the partially hydrogenated derivatives of the heterocyclic systems enumerated below. The terms "aryl" and "heteroaryl" as used herein refers to an aryl, which can be optionally unsubstituted or mono-, di- or tri substituted, or a heteroaryl, which can be optionally unsubstituted or mono-, di- or tri substituted. Examples of "aryl" and

"heteroaryl" include, but are not limited to, phenyl, biphenyl, indenyl, naphthyl (1- naphthyl, 2-naphthyl), N-hydroxytetrazolyl, N-hydroxytriazolyl, N-hydroxyimidazolyl, anthracenyl (1 -anthracenyl, 2-anthracenyl, 3-anthracenyl), phenanthrenyl, fluorenyl, pentalenyl, azulenyl, biphenylenyl, thiophenyl (1-thienyl, 2-thienyl), furyl (1 -furyl, 2- furyl), furanyl, thiophenyl, isoxazolyl, isothiazolyl, 1 ,2,3-triazolyl, 1 ,2,4-triazolyl, pyranyl, pyridazinyl, pyrazinyl, 1 ,2,3-triazinyl, 1 ,2,4-triazinyl, 1 ,3,5-triazinyl, 1 ,2,3- oxadiazolyl, 1 ,2,4-oxadiazolyl, 1 ,2,5-oxadiazolyl, 1 ,3,4-oxadiazolyl, 1 ,2,3-thiadiazolyl, 1 ,2,4-thiadiazolyl, 1 ,2,5-thiadiazolyl, 1 ,3,4-thiadiazolyl, tetrazolyl, thiadiazinyl, indolyl, isoindolyl, benzofuranyl, benzothiophenyl (thianaphthenyl), indolyl, oxadiazolyl, isoxazolyl, quinazolinyl, fluorenyl, xanthenyl, isoindanyl, benzhydryl, acridinyl, benzisoxazolyl, purinyl, quinazolinyl, quinolizinyl, quinolinyl, isoquinolinyl, quinoxalinyl, naphthyridinyl, phteridinyl, azepinyl, diazepinyl, pyrrolyl (2-pyrrolyl), pyrazolyl (3- pyrazolyl), 5-thiophene-2-yl-2H-pyrazol-3-yl, imidazolyl (1-imidazolyl, 2-imidazolyl, 4- imidazolyl, 5-imidazolyl), triazolyl (1 ,2,3-triazol-1-yl, 1 ,2,3-triazol-2-yl, 1 ,2,3-triazol-4- yl, 1 ,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxazolyl, 5-oxazolyl), thiazolyl (2-thiazolyl, 4-thiazolyl, 5-thiazolyl), pyridyl (2-pyridyl, 3-pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl), pyrazinyl, pyridazinyl (3-pyridazinyl, 4- pyridazinyl, 5-pyridazinyl), isoquinolyl (1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5- isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl), quinolyl (2-quinolyl, 3-quinolyl, 4- quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl), benzo[b]furanyl (2- benzo[b]furanyl, 3-benzo[b]furanyl, 4-benzo[b]furanyl, 5-benzo[b]furanyl, 6- benzo[b]furanyl, 7-benzo[b]furanyl), 2,3-dihydro-benzo[b]furanyl (2-(2,3-dihydro- benzo[b]furanyl), 3-(2,3-dihydro-benzo[b]furanyl), 4-(2,3-dihydro-benzo[b]furanyl), 5- (2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro-benzo[b]furanyl), 7-(2,3-dihydro- benzo[b]furanyl)), benzo[b]thiophenyl (2-benzo[b]thiophenyl, 3-benzo[b]thiophenyl, 4- benzo[b]thiophenyl, 5-benzo[b]thiophenyl, 6-benzo[b]thiophenyl, 7-benzo[b]thiophenyl), 2,3-dihydro-benzo[b]thiophenyl (2-(2,3-dihydro-benzo[b]thiophenyl), 3-(2,3-dihydro- benzo[b]thiophenyl), 4-(2,3-dihydro-benzo[b]thiophenyl), 5-(2,3-dihydro- benzo[b]thiophenyl), 6-(2,3-dihydro-benzo[b]thiophenyl), 7-(2,3-dihydro- benzo[b]thiophenyl)), indolyl (1 -indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6- indolyl, 7-indolyl), indazolyl (1-indazolyl, 2-indazolyl, 3-indazolyl, 4-indazolyl, 5- indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl, (1 -benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 8- benzimidazolyl), benzoxazolyl (1-benzoxazolyl, 2-benzoxazolyl), benzothiazolyl (1- benzothiazolyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl (1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl). Non-limiting examples of partially hydrogenated derivatives are 1 ,2,3,4- tetrahydronaphthyl, 1 ,4-dihydronaphthyl, pyrrolinyl, pyrazolinyl, indolinyl, oxazolidinyl, oxazolinyl, oxazepinyl and the like.

As used herein the term "acyl" refers to a carbonyl group -C(=0) R wherein the R group is any of the above defined groups. Specific examples are formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, benzoyl and the likes.

Optionally substituted" as applied to any group means that the said group may, if desired, be substituted with one or more substituents, which may be the same or different. Optionally substituted alkyl' includes both 'alkyl' and 'substituted alkyl'.

Examples of suitable substituents for "substituted" and "optionally substituted" moieties include halo (fluoro, chloro, bromo or iodo), C _1-6 alkyl, C _3-6 cycloalkyl, hydroxy, C _1-6 alkoxy, cyano, amino, nitro, C _1-6 alkylamino, C _2- 6 alkenylamino, di-C _1-6 alkylamino, C _1-6 acylamino, di-C _1-6 acylamino, C _1-6 aryl, C _1-6 arylamino, C _1-6 aroylamino, benzylamino, C _1-6 arylamido, carboxy, C _1-6 alkoxycarbonyl or (C _1-6 aryl)(C _1-10 alkoxy)carbonyl, carbamoyl, mono-C _1-6 carbamoyl, di-C _1-6 carbamoyl or any of the above in which a hydrocarbyl moiety is itself substituted by halo, cyano, hydroxy, C _1-2 alkoxy, amino, nitro, carbamoyl, carboxy or C _1-2 alkoxycarbonyl. In groups containing an oxygen atom such as hydroxy and alkoxy, the oxygen atom can be replaced with sulphur to make groups such as thio (SH) and thio-alkyl (S-alkyl). Optional substituents therefore include groups such as S-methyl. In thio-alkyl groups, the sulphur atom may be further oxidised to make a sulfoxide or sulfone, and thus optional substituents therefore includes groups such as S(0)-alkyl and S(0) ₂ -alkyl.

Substitution may take the form of double bonds, and may include heteroatoms. Thus an alkyl group with a carbonyl (C=0) instead of a CH ₂ can be considered a substituted alkyl group.

Substituted groups thus include for example CFH ₂ , CF ₂ H, CF ₃ , CH ₂ NH ₂ , CH ₂ OH, CH ₂ CN, CH ₂ SCH ₃ , CH ₂ OCH ₃ , OMe, OEt, Me, Et, -OCH ₂ 0-, C0 ₂ Me, C(0)Me, /-Pr, SCF ₃ , S0 ₂ Me, NMe ₂ , CONH ₂ , CONMe ₂ etc. In the case of aryl groups, the substitutions may be in the form of rings from adjacent carbon atoms in the aryl ring, for example cyclic acetals such as 0-CH ₂ -0.

Experimental

General Biology Methods

A person of skill in the art will be able to determine the pharmacokinetics and bioavailability of the compound of the invention using in vivo and in vitro methods known to a person of skill in the art, including but not limited to those described below and in Gallant-Haidner et al, 2000 and Trepanier et al, 1998 and references therein. The bioavailability of a compound is determined by a number of factors, (e.g. water solubility, cell membrane permeability, the extent of protein binding and metabolism and stability) each of which may be determined by in vitro tests as described in the examples herein, it will be appreciated by a person of skill in the art that an

improvement in one or more of these factors will lead to an improvement in the bioavailability of a compound. Alternatively, the bioavailability of the compound of the invention may be measured using in vivo methods as described in more detail below, or in the examples herein.

In order to measure bioavailability in vivo, a compound may be administered to a test animal (e.g. mouse or rat) both intraperitoneally (i.p.) or intravenously (i.v.) and orally (p.o.) and blood samples are taken at regular intervals to examine how the plasma concentration of the drug varies over time. The time course of plasma concentration over time can be used to calculate the absolute bioavailability of the compound as a percentage using standard models. An example of a typical protocol is described below. For example, mice or rats are dosed with 1 or 3 mg/kg of the compound of the invention i.v. or 1 , 5 or 10 mg/kg of the compound of the invention p.o.. Blood samples are taken at 5 min, 15 min, 1 h, 4 h and 24 h intervals, and the concentration of the compound of the invention in the sample is determined via LCMS-MS. The time- course of plasma or whole blood concentrations can then be used to derive key parameters such as the area under the plasma or blood concentration-time curve (AUC - which is directly proportional to the total amount of unchanged drug that reaches the systemic circulation), the maximum (peak) plasma or blood drug concentration, the time at which maximum plasma or blood drug concentration occurs (peak time), additional factors which are used in the accurate determination of bioavailability include: the compound's terminal half-life, total body clearance, steady-state volume of distribution and F%. These parameters are then analysed by non-compartmental or compartmental methods to give a calculated percentage bioavailability, for an example of this type of method see Gallant-Haidner et al, 2000 and Trepanier et al, 1998, and references therein.

The efficacy of the compound of the invention may be tested using one or more of the methods described below: 1. Assays for evaluating stability, solubility and metabolism

Microsome stability assay

Rate of metabolism in microsomes may be tested as follows:

Mouse or human liver microsomes were diluted with buffer C (0.1 M Potassium

Phosphate buffer, 1 .0 mM EDTA, pH 7.4) to a concentration of 2.5 mg/mL. Microsomal stability samples were then prepared by adding 50 μΙ_ of 5 μΜ compound spiking solution (0.5 μΙ_ 10 mM DMSO stock solution in 9.5 μΙ_ ACN, added to 990 μΙ_ Buffer C) to 50 μΙ_ of microsomal solution (2.5 mg/mL), 1 10 μΙ_ Buffer C and mixed well. All samples were pre-incubated for approximately 15 minutes at 37°C. Following this, the reaction was initiated by adding 40 μΙ_ of the NADPH solution (12.5 mM) with gentle mixing. Aliquots (40 μΙ_) were removed at 0, 15, 30, 45 and 60 minutes and quenched with ACN containing internal standard (120 μΙ_). Protein was removed by centrifugation (4000 rpm, 15 min) and the sample plate analysed for compound concentration by LC- MS/MS. Half-lives were then calculated by standard methods, comparing the concentration of analyte with the amount originally present.

Hepatocyte stability assay Cryopreserved hepatocytes, previously stored in liquid nitrogen are placed in a 37 ± 1 °C shaking water bath for 2 min ± 15 sec. The hepatocytes are then added to 10X volume of pre-warmed Krebs-Henseleit bicarbonate (KHB) buffer (2000mg/L glucose, without calcium carbonate and sodium bicarbonate, Sigma), mixed gently and centrifuged at 500 rpm for 3 minutes. After centrifugation, the supernatant is carefully removed and a 10X volume of pre-warmed KHB buffer added to resuspend the cell pellet. This is mixed gently and centrifuged at 500 rpm for 3 minutes. The supernatant is then removed and discarded. The cell viability and yield are then determined by cell counts, and these values used to generate human hepatocyte suspensions to the appropriate seeding density (viable cell density = 2 ^χ 106 cells/ml_).A 2X dosing solution is prepared in pre-warmed KHB (1 % DMSO) (200 μΜ spiking solution: 20 μΙ_ of substrate stock solution (10 mM) in 980 μΙ_ of DMSO, 2X dosing solution: 10 μΙ_ of 200 μΜ spiking solution in 990 μΙ_ of KHB (2μΜ after dilution). 50 μΙ_ of pre-warmed 2X dosing solution is added to the wells and 50 μΙ_ of pre-warmed hepatocyte solution (2 ^χ 106 cells/mL) added and timing started. The plate is then incubated at 37°C100 μΙ_ of acetonitrile containing internal standard is added to each the wells after completion of incubation time (0, 15, 30, 60 and 120 minutes) mixed gently, and 50 μΙ_ of pre-warmed hepatocyte solution added (2 106 cells/mL). At the end of the incubation, cell viability is determined. Samples are centrifuged at 4000 rpm for 15 minutes at 4°C, supernatants diluted 2-fold with ultrapure water and compound levels analysed by LC-MS/MS.

Test compounds are prepared as stock solutions in DMSO at 10mM concentration. The stock solutions are diluted in duplicate into PBS, pH7.4 in 1.5ml_ Eppendorf tubes to a target concentration of 100μΜ with a final DMSO concentration of 1 % (e.g. 4μΙ_ of 10mM DMSO stock solution into 396μΙ_ 100mM phosphate buffer). Sample tubes are then gently shaken for 4 hours at room temperature. Samples are centrifuged (10min, 15000rpm) to precipitate undissolved particles. Supernatants are transferred into new tubes and diluted (the dilution factor for the individual test article is confirmed by the signal level of the compound on the applied analytical instrument) with PBS. Diluted samples are then mixed with the same volume (1 :1 ) of MeOH. Samples are finally mixed with the same volume (1 :1 ) of ACN containing internal standard for LC-MS/MS analysis.

Water solubility assay Water solubility may be tested as follows: A 10 mM stock solution of the sanglifehrin analogue is prepared in 100% DMSO at room temperature. Triplicate 0.01 mL aliquots are made up to 0.5 mL with either 0.1 M PBS, pH 7.3 solution or 100% DMSO in amber vials. The resulting 0.2 mM solutions are shaken, at room temperature on an IKA® vibrax VXR shaker for 6 h, followed by transfer of the resulting solutions or

suspensions into 2 mL Eppendorf tubes and centrifugation for 30 min at 13200 rpm. Aliquots of the supernatant fluid are then analysed by the LCMS method as described above.

Alternatively, solubility in PBS at pH7.4 may be tested as follows: A calibration curve is generated by diluting the test compounds and control compounds to 40μΜ, 16μΜ, 4μΜ, 1 .6μΜ, 0.4μΜ, 0.16μΜ, 0.04μΜ and 0.002μΜ, with 50% MeOH in Η20. The standard points are then further diluted 1 :20 in MeOH:PBS 1 :1. The final

concentrations after 1 :20 dilution are 2000nM, 800nM, 200nM, 80nM, 20nM, 8nM, 2nM and 1 nM. Standards are then mixed with the same volume (1 :1 ) of ACN containing internal standard (hydroxymacrocycle, 6). The samples are centrifuged (5min,

12000rpm), then analysed by LC/MS.

2. Assays for evaluating cell permeability

Caco-2 permeability assay

Cell permeability may be tested as follows: The test compound is dissolved to 10mM in DMSO and then diluted further in buffer to produce a final 10μΜ dosing concentration. The fluorescence marker lucifer yellow is also included to monitor membrane integrity. Test compound is then applied to the apical surface of Caco-2 cell monolayers and compound permeation into the basolateral compartment is measured. This is performed in the reverse direction (basolateral to apical) to investigate active transport (efflux). LC-MS/MS is used to quantify levels of both the test and standard control compounds (such as Propanolol and Acebutolol). 3. Assays for evaluating potency

Nrf2 induction assay and NFKB inhibition assay

Potency can be assessed using cell signalling pathway specific cell lines with beta- lactamase (bla) reporter activity (SelectScreen, ThermoFisher). When a pathway is activated or inhibited beta-lactamase reporter activity is modulated and can be measured quantitatively and selectively. In antagonist (inhibitor) mode, as is used in the N FKB assay, a serial dilution of test compound or the known inhibitor Withaferin A is added to wells containing cells and medium. The plate is pre-incubated and then the known activator TNF-alpha is added at the pre-determined EC80 concentration. The plate is incubated and then analyzed. In agonist (activator) mode, as is used in the Nrf2 assay, cells in medium are pre- incubated and then a serial dilution of control activator (tBHQ) or test compound is added to the wells. Plates are incubated and then analyzed.

Dose response curves are generated, based on the data from which the relative EC50/IC50 values for each compound are calculated. More potent compounds are those with lower EC50/IC50 values.

Materials

Unless otherwise indicated, all reagents used in the examples below are obtained from commercial sources.

Examples

Compounds of the invention were characterised by a combination of NMR

spectroscopy and mass spectrometry.

Example 1 - Compound 1 o

NH ₂ .HCI

H

iercaptoethylamino)-1-propanone

methyl (E)-3-[2(-propionylaminoethylthio)carbonyl]acrylate (1)

Propionic anhydride (1 1 .7 g, 89.7 mmol) and aqueous KOH (8 M, to maintain pH 8) were added dropwise to a stirred solution of 2-aminoethanethiol (3.40 g, 30.0 mmol) in water (24 mL). The mixture was neutralized by adding 2M HCI and stirred for 1 hour at room temperature. The solution was cooled with an ice bath and solid KOH (6.00 g, 105 mmol) was added slowly. The mixture was stirred for 50 minutes at room temperature then saturated with NaCI and neutralized with 6M HCI. The mixture was extracted with CH ₂ CI ₂ (4 30 mL) and the combined CH ₂ CI ₂ extracts were dried (Na ₂ S0 ₄ ) and then the solvent removed in vacuo to give 1-(2-mercaptoethylamino)-1- propanone.

Oxalyl dichloride (97.6 g, 769 mmol) was added to a suspension of monomethyl fumarate (50 g, 384 mmol) in DCM (500 mL). DMF (0.2 mL) was added and the reaction was stirred at room temperature for 2 hours. The reaction solution was concentrated in vacuo to remove DCM and excess oxalyl dichloride and the residue dissolved in Et ₂ 0 (1000 mL). A solution of 1-(2-mercaptoethylamino)-1-propanone (30.7 g, 230 mmol) in Et ₂ 0 (100 mL) was added and the mixture stirred at room temperature for 2 hours. The solvent was removed in vacuo and the residue was dissolved in water and EtOAc. The mixture was basified to pH 7-8 by aqueous Na ₂ C0 ₃ and extracted twice with EtOAc. The combined organic layers were dried over sodium sulfate then the solvent removed in vacuo and methyl (£)-3-[(2- propionylaminoethylthio)carbonyl]acrylate (1 ) isolated by column chromatography.

Example 2 - Compound 2

N- Acetyl-cysteine (100.0 g, 613 mmol) was dissolved in DMF (600 mL) and

triphenylmethyl chloride (179.4 g, 643 mmol) was added and the reaction mixture was stirred at room temperature overnight. The mixture was diluted with water and extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate and filtered. The solvent was removed in vacuo to give compound 2-1. lodoethane (144.3 g, 925 mmol) was added to a suspension of 2-1 (250.0 g, 617 mmol) and K ₂ C0 ₃ (170.4 g, 1233 mmol) in DMF (1250 ml). The reaction mixture was stirred at room temperature overnight then diluted with ice-water and extracted twice with ethyl acetate. The combined organic layers were washed with water, brine, dry over sodium sulfate and filtered. The solvent was removed from the filtrate in vacuo to give compound 2-2. TFA (480 mL) was added to a solution of 2-2 (240 g, 554 mmol) and triethylsilane (128.7 g, 1 107 mmol) in dichloromethane (2.4 L) at 0 °C and the reaction mixture allowed to stir at room temperature overnight. The solvent was removed in vacuo and compound 2-3 isolated by column chromatography. To a suspension of monomethyl fumarate (60 g, 461 mmol) in DCM (600 mL) was added oxalyl dichloride (1 17.1 g, 922 mmol). DMF (5 drops) was added and the reaction was stirred at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure to remove DCM and excess oxalyl dichloride. The residue was dissolved in Et ₂ 0 (600 mL). Then a solution of 2-3 (44.1 g, 231 mmol) in Et ₂ 0 (100 mL) was added. The mixture was stirred at room temperature overnight. The suspension was filtered and washed with Et ₂ 0 (200 mL). The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give methyl (£)-3-[(2/?)-2- acetylamino-2-ethoxycarbonylethylthio)carbonyl]acrylate (compound 2) asslight yellow solid.

N- Acetyl-cysteine (100.0 g, 613 mmol) was dissolved in DMF (600 ml.) and triphenylmethyl chloride (179.4 g, 643 mmol) was added in portions and the reaction mixture was stirred at room temperature overnight. The mixture was diluted with water and extracted twice with ethyl acetate. The combined organic layers were washed with brine, dry over sodium sulfate and filtered. The solvent was removed in vacuo to give compound 2-1. 2-1 (3.3 g, 8.1 mmol) and diethylamine (3.0 g, 40.7 mmol) were dissolved in DMF (20 ml) and cooled in an ice-water bath. HATU (6.2 g, 16.3 mmol) was added and the reaction was stirred at room temperature overnight. The reaction mixture was diluted with water and extracted twice with ethyl acetate. The combined organic layers were washed with water, brine, dried over sodium sulfate. The solvent was evaporated in vacuo and compound 3-2 isolated by column chromatography. TFA (5.8 ml.) was added to a solution of 3-2 (2.9 g, 6.3 mmol) and triethylsilane (1.46 g, 12.6 mmol) in dichloromethane (60 ml.) at 0 °C. The reaction mixture was stirred at room temperature overnight then the solvent was evaporated in vacuo and compound 3-3 isolated by column chromatography. Oxalyl dichloride (975 mg, 7.7 mmol) was added to a suspension of monomethyl fumarate (1 .0 g, 7.7 mmol) in DCM (15 ml.) then DMF (1 drop) was added and the reaction was stirred at room temperature for 4 hours. The reaction solution was cooled to -78 °C and a solution of 3-3 (838 mg, 3.8 mmol) in DCM (2 ml.) was added. The mixture was stirred at room temperature overnight then the suspension was filtered and washed with DCM (10 ml_). The solvent was removed in vacuo and methyl (£)-3-[(2/?)-2-acetylamino-3-(diethylamino)-3- oxopropylthio)carbonyl]acrylate (compound 3) was isolated by column chromatography.

Example 4 - compound 4

(2-1) (2-2) (2-3)

methyl (E)-4{(1 R)-1-ethoxycarbonyl-2- [(methylthio]car onyl]ethylamino)-4-oxo-2-butenoate (4) To a suspension of monomethyl fumarate (40.0 g, 307 mmol) in DCM (400 ml.) was added oxalyl dichloride (43.0 g, 338 mmol). DMF (5 drops) was added and the reaction was stirred at room temperature for 3 hours. The reaction mixture was cooled to -78 °C before a solution of compound 2-3 (from example 2, 35.3 g, 184 mmol) in DCM (100 ml.) was added dropwise under nitrogen. After addition, the mixture was warmed to room temperature and stirred overnight. The reaction mixture was quenched with water (700 ml.) and extracted with DCM twice. The combined organic layers were dried over sodium sulfate, concentrated and purified by silica gel column chromatography to give methyl (£)-4-{(1 /?)-1-ethoxycarbonyl-2-[(methylthio)carbonyl]ethylamino}-4-o xo-2- butenoate (compound 4) as white solid.

Example 5 - compound 5

(5)

To a suspension of monomethyl fumarate (4.5 g, 35 mmol) in DCM (50 ml.) was added oxalyl dichloride (8.8 g, 69 mmol). Then DMF (3 drops) was added and the reaction was stirred at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure to remove DCM and excess oxalyl dichloride. The residue was dissolved in Et ₂ 0 (70 ml_). Then a solution of compound 3-3 (from example 3, 6.0 g, 28 mmol) in Et ₂ 0 (30 ml.) was added. The mixture was stirred at room temperature for 2 hours before concentrated under reduced pressure. The residue was treated with water and extracted with EtOAc twice. The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give methyl (£)-4-[(1 /?)-2-(ethylamino)-1-

{[(methylthio)carbonyl]methyl}-2-oxoethylamino]-4-oxo-2-b utenoate (compound 5) as off-white solid. Example 6 - Analysis of caco-2 permeability

A selection of compounds of the invention were tested for their caco-2 permeability using the caco-2 bidirectional permeability assay, as described in the general methods.

As can be seen 1 , 2, 3 and 5 have a higher A to B permeability than Monomethyl fumarate, suggesting they are more cell permeable. The Efflux ratio of 1 , 2, 3, 4 and 5 are all lower than MMF, suggesting they are all less susceptible to efflux.

N/A ^* : DMF analysis led to very low counts in all compartment in the caco-2 assay following dosing with DMF, possibly due to instability in the caco-2 assay system, because of rapid metabolism or degradation.

Example 7 - Analysis of Nrf2 activation

A selection of compounds of the invention were tested in an Nrf2 induction assay as described in the general methods.

Compound Nrf2 activation EC50 (nM)

Dimethyl fumarate 14000

Monomethyl fumarate 40800

1 7980

3 3670

4 1 1 100 As can be seen from the data, 1 3 and 4 are more potent than both dimethyl fumarate and monomethyl fumarate at activating the Nrf2 pathway in this assay.

Example 8 - Analysis of ΝίκΒ pathway inhibition

A selection of compounds of the invention were tested in an ΝίκΒ inhibition assay as described in the general methods.

As can be seen from the data, 1 , 2, 3, 4 and 5 are all more potent than dimethyl fumarate and monomethyl fumarate at inhibiting the N FKB pathway in this assay.

All references referred to in this application, including patent and patent applications, are incorporated herein by reference to the fullest extent possible.

Throughout the specification and the claims which follow, unless the context requires otherwise, the word 'comprise', and variations such as 'comprises' and 'comprising', will be understood to imply the inclusion of a stated integer, step, group of integers or group of steps but not to the exclusion of any other integer, step, group of integers or group of steps.

The application of which this description and claims forms part may be used as a basis for priority in respect of any subsequent application. The claims of such subsequent application may be directed to any feature or combination of features described herein. They may take the form of product, composition, process, or use claims and may include, by way of example and without limitation, the following claims: All references referred to in this application, including patent and patent applications, are incorporated herein by reference to the fullest extent possible.

Throughout the specification and the claims which follow, unless the context requires otherwise, the word 'comprise', and variations such as 'comprises' and 'comprising', will be understood to imply the inclusion of a stated integer, step, group of integers or group of steps but not to the exclusion of any other integer, step, group of integers or group of steps. The word "comprise" includes "contain" and "consist of.