WO2012056229A1

WO2012056229A1 - Inflammatory disease

Info

Publication number: WO2012056229A1
Application number: PCT/GB2011/052073
Authority: WO
Inventors: Robin Mark Bannister; John Brew
Original assignee: Biocopea Limited
Priority date: 2010-10-29
Filing date: 2011-10-25
Publication date: 2012-05-03
Also published as: GB201018302D0; GB2484977A

Abstract

The invention relates to the treatment of inflammatory diseases, and especially Th-1 mediated inflammatory diseases. In particular, the invention relates to the treatment of Th- 1 mediated inflammatory diseases using a range of related 1-phenyl-2-amino ethanol, ethanal and ethane derivatives, and to the use of these compounds in methods of treatment.

Description

INFLAMMATORY DISEASE

The present invention relates to the treatment of inflammatory diseases, and especially Th- 1 mediated inflammatory diseases. In particular, the invention relates to the treatment of Th-1 mediated inflammatory diseases using a range of related 1 -phenyl-2-amino ethanol, e hanal and ethane derivatives, and to the use of these compounds in methods of treatment.

The defence against disease is critical for the survival of all animals, and the mechanism employed for this purpose is the animal immune system. The immune system is complex, and involves two main divisions, (i) innate immunity, and (h) adaptive immunity. The innate immune system includes the cells and mechanisms that defend the host from infection by invading organisms, in a non-specific manner. Leukocytes, which are involved with the innate system, include inter alia phagocytic cells, such as macrophages, neutrophils and dendritic cells. The innate system is fully functional before a pathogen enters the host.

In contrast, the adaptive system is only initiated after the pathogen has entered the host, at which point it develops a defence specific to that pathogen. The cells of the adaptive immune system are called lymphocytes, the two main categories of which are B cells and T Cells. B cells are involved in the creation of neutralising antibodies that circulate in blood plasma and lymph and form part of the humoral immune response. T cells play a role in both the humoral immune response and in cell-mediated immunity. There are several subsets of activator or effector T cells, including cytotoxic T cells (CD8+) and "helper" T cells (CD4+), of which there are two main types known as Type 1 helper T cells (Thl) and Type 2 helper T cell (Th2).

Thl cells promote a cell-mediated adaptive immune response, which involves the activation of macrophages and stimulates the release of various cytokines, such as IFNy, TNF- and IL- 2, in response to an antigen. These cytokines influence the function of other cells in the adaptive and innate immune responses, and result in the destruction of micro- organisms. Generally, Thl responses are more effective against intracellular pathogens, such as viruses and bacteria present inside host cells. A Th2 response, however, is characterised by the release of IL-4, which results in the activation of B cells to make neutralising antibodies, which lead the humoral immunity. Th2 responses are more effective against extracellular pathogens, such as parasites and toxins located outside host cells. Accordingly, the humoral and cell-mediated responses provide quite different mechanisms against an invading pathogen.

Interleukin-10 (IL-10), also known as human cytokine synthesis inhibitory factor (CSIF), is an anti-inflammatory cytokine. It is produced primarily by monocytes and, to a lesser extent, by lymphocytes, and has pleiotropic effects in immunoregulation and inflammation. IL-10 down-regulates the expression of Thl cytokines (such as IFNy, TNF-oc and IL-12), MHC class II antigens, and co-stimulatory molecules on macrophages. It also enhances B cell survival, proliferation, and antibody production. Furthermore, IL-10 can block NF-κΒ activity, and is involved in the regulation of the JAK-STAT signaling pathway. Knockout studies in mice have suggested the function of IL-10 as an essential immunoregulator in the intestinal tract, and patients with Crohn's disease react favorably towards treatment with bacteria producing recombinant IL-10, showing the importance of this cytokine for counteracting excessive immunity in the human body.

IL-10 is a validated target in inflammatory disease, and has been shown to be essential for immunotolerance and the control of Thl immunity (O'Garra et al., 2008, Immunol. Rev., 223:114-31). Systemic adnoinistration of exogenous IL-10 in early clinical trials showed some initial promise in the treatment of various diseases, including rheumatoid arthritis, Crohn's disease, psoriasis and cystic fibrosis. However, problems associated with these early trials were that systemically administered exogenous IL-10 did not dampen exaggerated Thl responses as predicted, possibly because tissue levels of IL-10 were too low (the half-life of IL-10 is short), or because IL-10 was not presented in the correct manner. Hence, concentrations of IFNy, TNF-ot and IL-12 actually increased to deleterious levels. Furthermore, a significant side effect of administering too much exogenous IL-10 is that it actually suppresses the immune system, rather than positively modulating it, and so results in serious immune-related problems.

In view of these problems, there is, therefore, clearly a need in the art for improved medicaments for use in the treatment of Thl -mediated diseases, and especially Thl - mediated inflammatory disorders, which do not suffer the immune-related problems observed in previous IL-10 trials. The inventors have determined that certain related 1- phenyl-2-amino ethane derivatives have the properties required to be useful in treating such diseases.

Hence, in a first aspect, there is provided a compound which is capable of increasing interleukin-10 (IL-10) production, for use in treating a Thl-mediated disease, wherein the IL-10 is endogenously produced by Th2 cells, dendritic cells and/or macrophages.

In a second aspect of the invention, there is provided a method of preventing, treating and/or ameliorating a Thl-mediated disease, the method comprising administering, to a subject in need of such treatment, a therapeutically effective amount of a compound which is capable of increasing interleukin-10 (IL-10) production, wherein the IL-10 is

endogenously produced by Th2 cells, dendritic cells and/ or macrophages.

In a third aspect, there is provided use of a compound, which is capable of inducing endogenous production of interleukin-10 (IL-10) by Th2 cells, dendritic cells and/or macrophages, for treating a Th-1 mediated disease.

The inventors carried out investigations on a number of different compounds that can induce IL-10 production, as they were aware that IL-10 production is a characteristic that indicates a switch from a Thl to a Th2 response. They have demonstrated that inducing the switch from a Thl to a Th2 response by up-regulating IL-10 production can be used to help treat Thl-mediated hyper-inflammation. Advantageously, by stimulating a Th2 response, by inducing the endogenous release of IL-10, B cells are activated, which produce neutralising antibodies, which lead the humoral immunity. It will be appreciated that Th2 responses are much more effective against extracellular pathogens, such as parasites and toxins located outside host cells, than Thl responses.

By way of example, Thl-mediated hyper-inflammation occurs during viral infections, and so the inventors believe that endogenously producing IL-10 by the Th2 cells upon adrninistration of the compound to the subject could be used to treat a respiratory collapse caused by a viral infection. It is known that some viruses, such as Herpes Simplex Virus (HSV), maintain their presence in the body by stimulating Thl immunity, and that therefore, triggering a switch to Th2 immunity would help treat herpes infections by allowing the body to attack the virus through natural killer cell immunity.

The inventors are of the view that IL-10 is a paracrine cytokine, and that, therefore, the compound used in the first, second and third aspects of the invention can be effectively used to increase endogenous IL-10 production in a paracrine manner. It will be appreciated that paracrine signalling can be a form of cell signalling in which the target cell is near or local to the signal-releasing cell. Thus, IL-10 can control the immune response at sites of inflammation in tandem with cell-cell interactions.

It is preferred that the compound which is capable of increasing endogenous IL-10 production is recognised by Th2 cells, dendritic cells and/ or macrophages. Thus, Th2 cells, dendritic cells and/or macrophages may phagocytise the compound, react with pathways in each of these cell types, and thereby endogenously produce IL-10. Preferably, therefore, the IL-10 is produced by Th2 cells, dendritic cells and/or macrophages, which are immunocompetent. Advantageously, in contrast to producing IL-10 by non-immune cells, which causes an imbalance in the immune system leading to infections and, in some cases cancer, endogenous production of IL-10 by immuno-competent Th2 cells, dendritic cells and/or macrophages, ensures that the immune system remains balanced, thereby avoiding infection.

Hence, the immune system is capable of regulating itself naturally, thereby reducing the risk of infections and cancer. The levels of IL-10 generated due to the regulator₎' process and feedback loops may modulate (e.g. decrease) Thl cytokine concentration, such as IFNy, T F-a and IL-12, but not suppress their production completely. This may be important because these Thl cytokines are needed to protect the body from infection. Thus, by stimulating production of IL-10 endogenously, it is possible to overcome the significant immune-related problems that are observed when the cytokine is added exogenously, resulting in over-production of IFNy, TNF-a and IL-12.

The inventors have determined that certain related 1 -phenyl-2-amino ethane derivatives have the properties required to be useful in treating Thl -mediated diseases. Thus, the compound, which is capable of increasing endogenous IL-10 production, may comprise a compound of formula I:-

wherein:- X is CO, CHOH or CH₂;

R¹ is H, or combined with R²;

R² is H, OH, a halogen, a substituted or unsubstituted amino group, a C_j.5 alkyl or alkoxyl group, optionally substituted with one or more O, OH, amino and/ or optionally C,_₃ alkyl substituted phenyl group, or combined with R¹;

R³ and R⁴ are each independendy H, OH, a halogen, a substituted or unsubstituted amino group, or a C,^ alkyl or alkoxyl group, optionally substituted with one or more O, OH, amino and/ or optionally C,_.3 alkyl substituted phenyl group;

R⁵ is H;

R⁶ is H, a C,_s alkyl group, or combined with R⁸;

R⁷ is H, or combined with R⁸;

R⁸ is combined with R⁶ or R⁷, or is a straight chain, branched or cyclo- C,-C₉ alkyl group, optionally including one or more hetero atom in its carbon skeleton and optionally substituted with one or more OH, and/or C₅_₆ aryl group, optionally substituted with one or more OH or C, ₅ alkoxyl or alkyl group;

when combined, R' and R², together with the associated ring carbon atoms, form an optionally O substituted cycloalkyl, cycloalkenyl, cycloheteroalkyl or cycloheteroalkenyl group of 5 or 6 carbon atoms, or 4 or 5 carbon atoms and a hetero atom;

when combined, R⁶ and R⁸, together with the nitrogen atom carrying R⁸ and the carbon atom carrying R⁶, form a 5 or 6 membered cycloheteroalkyl group; and,

when combined, R⁷ and R⁸, together with the nitrogen atom carrying them, form an optionally benzyl substituted 5 or 6 membered cycloheteroalkyl group;

or a pharmaceutically acceptable salt or solvate thereof. R² can be a hydroxyalkyl group, or include a carbonyloxy group and is, preferably, H, OH, HOCH₂-, 0=CHNH-, CH₃PhCOO-, NH₂COO-, or a halogen, preferably chlorine. R² is more preferably H, OH or CI. R₃ is preferably H, NH₂, OH or CH₃PhCOO-. R³ is more preferably H, NH, or OH. R⁴ is preferably H, OH, NH₂COO-, or a halogen, preferably, chlorine. R⁴ is more preferably H or CI. R⁶ is preferably methyl, ethyl, or H, more preferably, methyl or ethyl and most preferably methyl. R⁷ is preferably H. R⁸ is preferably straight chain or branched C₂-C₆ alkyl group, optionally substituted with OH, phenyl, PhOH or PhOCH₃. R⁸ is more preferably tert. butyl, isopropyl, -C(CH₃)₂OH, - CH₂PhOCH₃,-(CH₂)₂PhOH, -CH(CH₃)CH₂CH₂Ph, or -CH(CH₃)CH₂CH₂PhOH and, most preferably, tert. butyl, -C(CH₃)₂OH, -(CH,)₂PhOH, -CH(CH₃)CH₂CH₂Ph, or - CH(CH₃)CH₂CH₂PhOH. R⁸ can also be:-

When combined, R¹ and R² preferably form the group:-

When R⁶ and R⁸ are combined it is preferred that, together with the nitrogen atom carrying R⁸ and the carbon atom carrying R⁶, they form a cycloheteroalkyl group of 5 carbon atoms and 1 nitrogen atom. When R' and R⁸ are combined it is preferred that they form the group:-

In the foregoing, Ph means phenyl and it is preferred that, when bi-substituted, any such phenyl group is 1, 4-substituted.

In preferred embodiments, the present invention involves a compound of formula I wherein:- X is CO, CHOH or CH₂; R' is H;

R² is H, OH, or a halogen;

R³ is H, OH or NH₂;

R⁴ is H, or a halogen;

R⁵ is H;

R^> is H, methyl or ethyl, or combined with R⁸;

R⁷ is H, or combined with R⁸;

R⁸ is combined with R⁶ or R⁷, or is tert. butyl, -C(CH₃)₂OH, -(CH^PhOH, - CH(CH₃)CH₂CH₂Ph, or -CH(CH₃)CH₂CH₂PhOH;

when combined, R⁶ and R⁸, together with the nitrogen atom carrying R⁸ and the carbon atom carrying R⁶, form a cycloheteroalkyl group of 5 carbon atoms and 1 nitrogen atom; and,

when R⁷ and R⁸ are

or a pharmaceutically acceptable salt or solvate thereof.

In all embodiments of the invention where R^s is not combined with R⁸, it is preferred for R^s to be a methyl or an ethyl gtoup, preferably a methyl group. In such preferred embodiments, it is also preferred that R¹, R⁴, R⁵ and R⁷ are H, R² is H or OH, and R³ is OH. In such preferred embodiments R⁸ can be -(CH^PhOH or - CH(CH₃)CH₂CH₂PhOH.

As described in the Examples, the inventors studied the effects of erytbro 2-(l,l- dimethylemyl)aniino-l-(3-chlorophenyr)propan-l-ol (denoted herein as BC1053, shown in Figure 1) and demonstrated in in vim and ex vivo models that (i) this compound surprisingly induces endogenous production of IL-10 by Th2 cells, dendritic cells and/or macrophages and (ii) the concentrations of the Thl cytokines, TNF-CC and IL- 2, were potently inhibited. Thus, the invention is based on the induction of Th2 immune cells to trigger the switch from a Thl to a Th2 immune response, and to thereby treat Thl -mediated hyper- inflammation, which is driven by these Thl cytokines. The inventors therefore believe that they are the first to demonstrate that, in addition to sharing other properties, the defined 1 -phenyl-2-amino ethanol, ethanal and ethane derivatives represented by Formula I can be used to stimulate endogenous production of IL-10, and reduce Thl cytokine production, and to thereby induce the switch from a Thl to a Th2 response, in such a way so as to be useful in the treatment of Thl -mediated inflammatory disease. In particular, these compounds may be used to combat respiratory disorders that are caused by acute viral infections, and which, in some cases (e.g. influenza infections), can cause death. Various metabolites of compound (I) (i.e. any compound of formula (I)) may also be used for stimulating endogenous production of IL-10 from Th2 cells, dendritic cells and/or macrophages. Compound (I), for use, in the invention, may be chiral. Hence, the compound (I) may include any diastereomer and enantiomer of the formula represented by (I). Diastereomers or enantiomers of (I) are believed to display potent cytokine modulatory activity, and such activities may be determined by use of appropriate in vitro and in vivo assays, which will be known to the skilled technician. It will also be appreciated that compounds for use in the invention may also include pharmaceutically active salts, e.g. the hydrochloride. In another embodiment, the compound represented by formula (I) may be the drug that is known and available under the trade name, bupropion. Bupropion is known to be metabolised in vivo into a number of different metabolites also of formula (I), an embodiment of which is shown in Figure 1. Therefore, buproprion or any of these metabolites may also be used for treating acute viral infections in accordance with the invention. Bupropion is metabolised non-stereoselectively to a number of enantiomers, but these compounds represent a relatively small proportion of the total metabolism of the parent drug. Compounds defined by formula (I) can therefore include these metabolites as racemates or as pairs of diastereoisomers or individual enantiomers, including the tbreo- and erytbrv-pah of diastereoisomers and the individual tbreo and erythro enantiomers. It is preferred that the compound defined by formula (I) includes the erythro enantiomer or enantiomers. - Si -

Exemplary bupropion metabolites include 2-(l,l-dime ylemyl)amino-l-(3- chlorophenyl)propan-l -ol, 2-(l ,1 -dimemyl-2-hydroxyethyl)amino-l -(3- chlorophenyl)propan-l -one, (1 S,2R)-erythto-2-(l ,1 -dimemylemyl)amino~l-(3- chlorophenyl)propan-l -ol, (1 R,2S)-erythro-2-(l ,1 -d½iethylemyl)arnino-l -(3- chlorophenyl)propan-l-ol, (lS,2S)-tJiieo-2-(l,l-dimemylemyl)arnino-l-(3- chlorophenyl)propan-l -ol and (1 R,2R)-threo-2-(l,l -dimemylemyl)amino-l -(3- chlorophenyl)propan- 1 -ol.

In anodier embodiment, compound (I) may be hydrobupropion (i.e. 2-(l,l- dimemylemyl)amino-l-(3-chlorophenyl)propan-l-ol). One isomer of hydrobupropion may be (+)-^reo-hydrobupropion, i.e. (R, R-hydrobupropion), and another isomer may be

It is preferred that the bupropion metabolite employed in any aspect of the invention is an R enantiomer, either at the first and/or second position.

Numerous disease conditions are believed to be associated with low levels of IL-10 (i.e. hypo-IL-10 disorders), or in situations where an increase in IL-10 concentration is either too slow or insufficient, and any of these condition may be treated in accordance with the invention. Preferably, the Thl -mediated disease, which may be treated, may be a Thl- mediated inflammatory disease, preferably systemic inflammatory disease. As described in the examples, the inventors have conducted several experiments in mice models which are known to be representative of human disease, for example septic shock, rheumatoid arthritis (RA), arthritic swelling, inflammatory bowel disease (IBD) and multiple sclerosis (MS).

Hence, the disease to be treated may be selected from a group of Thl -mediated diseases consisting of rheumatoid arthritis (RA); psoriatic arthritis; psoriasis; inflammatory bowel syndrome (IBD); Crohn's disease; ulcerative colitis; multiple sclerosis (MS); flu, including pandemic flu; respiratory disorders, for example those caused by viruses, such as respirator}' syncytial virus (RSV); cystic fibrosis; herpes, including genital herpes; asthma and allergies; sepsis and septic shock; bacterial pneumonia; bacterial meningitis; dengue hemorrhagic fever; diabetes Type I; endometriosis; prostatitis; uveitis; uterine ripening; and age-related macular degeneration.

The Thl -mediated disease may be virally, bacterially or chemically (e.g. environmentally) induced. For example, a virus causing the Thl -mediated disease may cause a chronic or acute infection, which may cause a respiratory disorder. Suitably, the virus causing the Thl- mediated disease may be Influenza.

Preferably, the Thl -mediated disease, which may be treated, is systemic inflammatory disease, for example flarnmatory bowel syndrome (IBD) or rheumatoid arthritis ( A).

It will be appreciated that the active compound may be used to treat a Thl -mediated disease in a monotherapy (i.e. use of the compound capable of stimulating endogenous IL- 10 production alone). Alternatively, the compound may be used as an adjunct to, or in combination with, known therapies used in treating Thl-mediated diseases.

The active compound may be combined in compositions having a number of different forms depending, in particular, on the manner in which the composition is to be used. Thus, for example, the composition may be in the form of a powder, tablet, capsule, liquid, ointment, cream, gel, hydrogel, aerosol, spray, micellar solution, transdermal patch, liposome suspension or any other suitable form that may be administered to a person or animal in need of treatment. It will be appreciated that the vehicle for medicaments according to the invention should be one which is well-tolerated by the subject to whom it is given, and preferably enables delivery of the agents across the blood-brain barrier, or the lungs.

Compositions comprising the active compound may be used in a number of ways. For instance, oral adrninistration may be required in which case the compound may be contained within a composition that may, for example, be ingested orally in the form of a tablet, capsule or liquid. Alternatively, the composition may be administered by injection into the blood stream. Injections may be intravenous (bolus or infusion) or subcutaneous (bolus or infusion). Alternatively, the composition comprising the active compound may be administered by inhalation (e.g. intranasally, or by mouth). Compositions may also be formulated for topical use. For instance, ointments may be applied to the skin. Topical application to the skin is particularly useful for treating infections of the skin or as a means of transdermal delivery to other tissues.

It will be appreciated that the amount of the active compound that is required is determined by its biological activity and bioavailability, which in turn depends on the mode of administration, the physicochemical properties of the compound and whether the compound is being used as a monotherapy, or in a combined therapy. The frequency of administration will also be influenced by the above-mentioned factors and particularly the half-life of the active compound within the subject being treated.

Optimal dosages to be administered may be determined by those skilled in the art, and will vary with the particular active compound in use, the strength of the preparation, the mode of administration, and the advancement of the disease condition. Additional factors depending on the particular subject being treated will result in a need to adjust dosages, including subject age, weight, gender, diet, and time of adrninistration.

It will be appreciated that a skilled person will be able to calculate required doses, and optimal concentrations of the active compound at a target tissue, based upon the pharmacokinetics of the active. Known procedures, such as those conventionally employed by the pharmaceutical industry (eg in vivo experimentation, clinical trials, etc.), may be used to establish specific formulations of the active compound and precise therapeutic regimes (such as daily doses of the compounds and the frequency of administtation).

Generally, a daily dose of between 0.00^g/kg of body weight and 60mg/kg of body weight of the active compound may be used for the prevention and/or treatment of a Thl- mediated disease depending upon which compound is used. Suitably, the daily dose is between 0.01|Ig/kg of body weight and 30mg/kg of body weight, more suitably between 0.01(Ig/kg of body weight and lOmg/kg of body weight or between 0.1(Xg/kg and 5mg/kg body weight, and most suitably between approximately O.lJIg/kg and 3mg/kg body weight. Daily doses of the active compound may be given as a single administration (e.g. a single daily injection or a single inhalation). A suitable daily dose may be between 0.07μg and 700mg (i.e. assuming a body weight of 70kg), or between 0.7C^g and 500mg, or between lOmg nd 450mg.

It is envisaged that medicaments comprising the active compound may be administered more than once to the subject in need of treatment. The compound may require administration twice or more times during a day. As an example, the active compound may be administered as two (or more depending upon the severity of the viral infection being treated) daily doses of between 0.(^g and 700mg (i.e. assuming a body weight of 70kg). A patient receiving treatment may take a first dose upon waking and then a second dose in the evening (if on a two dose regime) or at 3- or 4-hourly intervals thereafter, and so on. It is envisaged that the compound may be administered every day (more than once if necessary) after the trigger for die Thl mediated inflammation.

Alternatively, a slow release device may be used to provide optimal doses of compounds according to the invention to a patient without the need to administer repeated doses.

Based on their findings that the compounds described herein may be used to increase the levels of endogenous production of IL-10 by Th2 cells, dendritic cells and/or

macrophages, and thereby reduce the levels of Thl cytokines, such as T F-OC and IL-12, to trigger the Thl to Th2 switch, the inventors believe that these effects of the compounds may be harnessed and used in the manufacture of clinically useful compositions. Hence, in a fourth aspect, there is provided a pharmaceutical composition comprising a therapeutically effective amount of a compound which is capable of increasing interleukin- 10 (IL-10) production, and a pharmaceutically acceptable vehicle, for use in the treatment of a Thl -mediated disease, wherein the IL-10 is endogenously produced by Th2 cells, dendritic cells and/or macrophages.

The compound is preferably represented by the general formula I. The Thl -mediated disease may be an inflammatory disease. Thus, the composition is preferably an anti-inflammatory pharmaceutical composition.

A "therapeutically effective amount" of the active compound is any amount which, when administered to a subject, results in increased levels of IL-10, and preferably decreased concentrations of TNF-OC and IL-12, and thereby provides treatment of a Thl -mediated disease.

For example, the therapeutically effective amount of the active compound used may be between 0.(^g and 700mg, between 0.7C^g and 500mg, between lOmg and 450mg, or between 50mg and 150mg.

A "subject" may be a vertebrate, mammal, or domestic animal, and is preferably a human being. Hence, medicaments according to the invention may be used to treat any mammal, for example human, livestock, pets, or may be used in other veterinary applications.

A "pharmaceutically acceptable vehicle" as referred to herein is any combination of known compounds known to those skilled in the art to be useful in formulating pharmaceutical compositions.

In one embodiment, the pharmaceutically acceptable vehicle may be a solid, and the composition may be in the form of a powder or tablet. A solid pharmaceutically acceptable vehicle may include one or more substances which may also act as flavouring agents, lubricants, solubilisers, suspending agents, dyes, fillers, glidants, compression aids, inert binders, sweeteners, preservatives, dyes, coatings, or tablet-dis tegrating agents. The vehicle may also be an encapsulating material. In powders, the vehicle is a finely divided solid that is in admixture with the finely divided active agent (i.e. the active compound which increases endogenous IL-10 levels). In tablets, the active agent may be mixed with a vehicle having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active agent. Suitable solid vehicles include, for example calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.

SUBSTITUTE SHEET (RULE 26 In another embodiment, the pharmaceutical vehicle may be a gel and the composition may be in the form of a cream or the like. In yet another embodiment, the pharmaceutical vehicle may be a liquid, and the pharmaceutical composition may be in the form of a solution. Liquid vehicles are used in preparing solutions, suspensions, emulsions, syrups, elixirs and pressurized compositions. The active compound may be dissolved or suspended in a pharmaceutically acceptable liquid vehicle such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid vehicle can contain other suitable pharmaceutical additives such as solubilisers, emulsifiers, buffers, preservatives, sweeteners, flavouring agents, suspending agents, thickening agents, colours, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid vehicles for oral and parenteral administration include water (partially containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the vehicle can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid vehicles are useful in sterile liquid form compositions for parenteral administration. The liquid vehicle for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellant.

Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by, for example, intramuscular, intrathecal, epidural, intraperitoneal, intravenous and particularly subcutaneous injection. The active compound may be prepared as a sterile solid composition that may be dissolved or suspended at the time of administration using sterile water, saline, or other appropriate sterile injectable medium.

The active compound may be administered orally in the form of a sterile solution or suspension containing other solutes or suspending agents (for example, enough saline or glucose to make the solution isotonic), bile salts, acacia, gelatin, sorbitan monoleate, polysorbate 80 (oleate esters of sorbitol and its anhydrides copolymerized with ethylene oxide) and the like. The active compound can also be administered orally either in liquid or solid composition form. Compositions suitable for oral administration include solid forms, such as pills, capsules, granules, tablets, and powders, and liquid forms, such as solutions, syrups, elixirs, and suspensions. Forms useful for parenteral administration include sterile solutions, emulsions, and suspensions.

The inventors also beKeve that compositions of the invention may be immobilised on or in a support substrate or matrix forming a lipid-rich formulation, which may be used as a delivery device to treat Thl -mediated disorders.

Hence, in a fifth aspect of the invention, there is provided a drug delivery device comprising:- (i) a pharmaceutical composition comprising a therapeutically effective amount of a compound which is capable of increasing endogenous i terleukin-10 (IL-10) production by Th2 cells, dendritic cells and/or macrophages; and

(ii) a support matrix. The delivery device may be a pessary or a vaginal ring or the like, which may be worn by a subject requiring treatment of a Th -mediated condition. For example, the device may be used to treat any disease characterised by a drop in IL-10 concentrations. It is known that the concentration of IL-10 decreases in pregnant women, as a result of foetus tolerance, and this initiates labour during child birth. Thus, the delivery device may be used by pregnant women to prevent or delay premature labour.

The support matrix may be made of a substrate material which is suitable for supporting the composition therein or thereon. The pharmaceutical composition in the device may be the composition of the fourth aspect. The composition may be immobilised on the matrix. In one embodiment, the matrix may comprise any material capable of melting at, or around, body temperature, such that, over time, the matrix dissolves thereby releasing the composition, which is absorbed by the subject.

The support matrix may a suitable gel or wax. For example, conventional materials for vaginal administration may be used, such as glycerol, gelatin, glyco-gelatin, macrogols

(polyethylene glycols), natural, synthetic or semi-synthetic hard fats, and fractionated palm kernel oil. All of the features described herein (including any accompanying claims, abstract and drawings), and/ or all of the steps of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Embodiments of the invention will now be further described, by way of example only, with reference to the following Examples, and to the accompanying diagrammatic drawings, in which: -

Figure 1 shows the chemical structure of one embodiment of a compound represented by formula I, for example a bupropion metabolite, which is denoted herein as BC1053.

References to the compound BC1053 herein refer to the compound shown in Figure 1;

Figure 2 shows the effect of the orally-dosed test compound (BC1053) in vivo on IL-10 levels in mice. The compound was administered at 3mg/kg, lOmg/kg and 30mg/kg;

Figure 3 shows the effect of the compound represented by formula I (BC1053) ex vivo on lipopolysaccharide-induced (LPS) blood cytokine levels in mice blood. The compound was administered at lOmg/kg, 30mg/kg and 60mg/kg;

Figure 4 is a table showing in vivo IL-10 and TNFa concentrations induced by LPS;

Figure 5 is a table summarising the effect of BC1053 in various disease models, including inter alia the lipopolysaccharide (LPS) model in mouse which is representative of septic shock, dexttan sulphate (DSS) and tti itrobenzene sulfonic acid (TNBS) induced colitis in mice which are representative of inflammatory bowel disease (IBD), and proteolipid protein (PLP) induced experimental autoimmune encephalitis which is representative of multiple sclerosis (MS). The table shows the effective doses of the test compound I (e.g. BC1053), and its effect;

Figure 6 summarises the results of the dextran sulphate (DSS) induced colitis model in mice, which is representative of IBD. lOmg/kg and 30mg/kg BC1053 were administered to the DSS-induced mice. As a control, the corticosteroid dexamethasone was administered at 0.2mg/kg. The superior efficacy of BC1053 in a recognised model of IBD is seen compared to the high dose of dexamethasone;

Figure 7 shows the DSS-induced colitis histology scores. The Figure shows 5% DSS only as negative control, 0.2mg/kg dexamethasone as positive control, and lOmg/kg and 30mg/kg of the test compound, BC1053; Figure 8 summarises the results of the TNBS-induced colitis model when mice were administered with either 30mg/kg BC1053 or lOmg/kg sulphasalazine (i.e. a sulphonamide antibiotic acting as a positive control). The data show the efficacy of administering BC1053 in a recognised model of IBD compared to the high dose of sulphasalazine;

Figure 9 shows the effect of 30mg/kg BC1053 on TNBS-induced colitis in mice compared to lOmg/kg sulphasalazine, as positive control. The mean composite clinical score refers to the mean scores of weight loss, stool consistency and rectal blood;

Figure 10 shows additional Thl cytokine (i.e. IL-12) effects of BC1053. μΜ and 10 μΜ BC1053 was administered to IL-12 explants. As can be seen, there is a clear reduction in IL-12 in the explant administered with 10 μΜ BC1053;

Figure 11 shows additional Thl cytokine (i.e. TNFa) effects of BC1053. Ι Μ and 10 μΜ BC1053 was administered to TNFa explants. As can be seen there is a clear reduction in IL-12 in the explant administered with 10 μΜ BC1053; and

Figure 12 shows the effect of BC1053 on proteolipid protein (PLP) induced experimental autoimmune encephalomyelitis (EAE) in SJL mice, which is a representative model of multiple sclerosis (MS). The mice were treated with lOmg/kg BC1053, or just the vehicle of 1 % methylcellulose (MC) or were untreated, as controls. The graph shows the effects of inducing immuno-tolerance through endogenous IL-10 elevation. Although there was litde effect in the first relapse, the second relapse was prevented in mice treated with BC1053.

Examples

The inventors carried out a range of in vivo and ex vivo experiments in order to determine the effects of various compounds represented by formula I on the endogenous production of the cytokine, IL10. The inventors have demonstrated that er thro 2-(l,l- dimemylemyl)amino-l-(3-chiorophenyl)propan-l-ol (denoted herein as BC1053, which is a bupropion metabolite, as shown in Figure 1) surprisingly induces endogenous production of IL-10.

Furthermore, they have demonstrated in various well-known and established mouse models that increasing endogenous production of IL-10 can be used to treat various human diseases, including septic shock, inflammatory bowel disease (IBD) and multiple sclerosis (MS). They have also shown that compounds of Formula I are able to reduce, in an in vivo model, the concentrations of both IL-12 and TNFa, which are Thl response cytokines (as is IFNy). Therefore, it is clear from the data described below that compounds, which are capable of increasing endogenous IL-10 production by immuno-competent Th2 cells, macrophages and dendritic cells can be effectively used for treating Thl -mediated diseases. Materials and Methods

In vivo lipopolysaccharide (LPS) induction

Female BALB/c mice (5 to 7 weeks old) were allowed to acclimatise and were provided with food and water ad libitum. Test compound was dosed orally with either vehicle only (1% carboxymethyl cellulose) or test compound at three doses (3, 10 and 30 mg/kg) in the same vehicle. Half an hour later, each mouse was challenged with a 1 mg/kg (5 ml/kg volume) intraperitoneal injection of lipopolysaccaride (LPS). Two hours after the LPS challenge, terminal blood was taken by cardiac puncture blood and collected in heparinised tubes. Samples were put on ice until they were centrifuged (6000xg for 5 minutes at 4°C), and the supernatant plasma was aliquoted, snap frozen in liquid nitrogen and then stored at -20°C. Plasma was analysed by ELISA technique for IL-10 levels. IL-10 concentrations were expressed as pg/ ml.

Ex vivo LPS induction

Female BALB / c mice (5 to 7 weeks old) were allowed to acclimatise and were provided food and water ad libitum. Test compound was dosed orally with either vehicle only (1% carboxymethylcellulose) or test compound at three doses (10, 30 and 60 mg/kg) in the same vehicle. Two and half hours later blood was collected from the treated mice into heparinised tubes and diluted 1 :1 in sterile RPMI. Blood cells were then plated out in triplicate and allowed for 30 minutes. Either LPS (10 g/ml) or phosphate buffered saline were then added and allow to culture for 12 hours after which culture supernatants were collected for IL-10 analysis by Luminex. IL-10 concentrations were then expressed as pg/ml. Dextran sulphate (DSS) induction

5% dextran sulphate (DSS) was given to the drinking water of BDF1 mice. The DSS initiates colonic inflammation through the disturbance of the mucosal barrier, and thereby results in colonic lesions, diarrhoea, weight loss and rectal bleeding. These symptoms are identical to human colitis, such as Crohn's disease and Ulcerative colitis. BC1053 was given orally from day 1 of the DSS insult, and the mice were monitored.

Tririitrobenzene sulfonic acid (TNBS) induction

5% TNBS in 50% ethanol was given rectally to Balb/ c mice. The TNBS initiates colonic inflammation through the disturbance of the mucosal barrier, and thereby results in colonic lesions, diarrhoea, weight loss and rectal bleeding. These symptoms are identical to human colitis, such as Crohn's disease and Ulcerative colitis. BC1053 was given orally from day 1 of the TNBS insult, and the mice were monitored.

TNBS cytokine explant experiments

1 cm piece of distal colon was removed, from animals in the TNBS experiments, faeces were removed and the piece was placed in 2-3 ml of Roswell Park Memorial Institute (RPMI) medium. Colons were washed 3 times using supplemented RPMI by vigorous shaking. The explants was placed in 1 ml of fresh sterile supplemented RPMI and cultured overnight, with and without 1 and ΙΟμΜ of BC1053.

Proteolipid protein (PLP) induced experimental autoimmune encephalomyelitis (EAE) in SJL mice

SJL mice (Harlan laboratories, Israel) on day 0, were injected with a single inoculation with freshly prepared proteolipid protein (PLP) solution in an emulsion of complete Freund's adjuvant (CFA), at a ratio of 125 g PLP/ 300 g CFA in 2 X 100 μΐ subcutaneous injections per mouse. In order to increase the blood brain barrier penetration all animals were subjected to supplemental immuno-stimulation with pertussis toxin (PT) (20 μg/kg ) by intraperitoneal injections on two occasions, once on day 0 of the study and thereafter 48 hours later (day 2). The same animals were also treated with either oral gavage of vehicle (water) or 10 mg/kg of BC1053, once a day, throughout the course of the experiment. Through the entire experiment (42 days), animals were checked daily for clinical signs (general observations of the health of the animal), body weights and EAE clinical scores (0 to 5 scale: 0 being no signs of neurological signs, 1 being distal tail limp and droop, 2 being hind leg weakness and paresis, wobbily walk and/or hind legs unsteady, 3 being hind leg paralysis, when moving animal dragging its hind legs, 4 being quadriplegia, full paralysis, animal unable to move, thin and emaciated and 5 being moribund or dead. Example 1— Stimulation Experiments using the mitogen. LPS

Plasma B cells can enter mitosis when they encounter an antigen matching their immunoglobulin. A mitogen is a chemical substance that triggers signal transduction pathways in which mitogen-activated protein kinase is involved, thereby encouraging a cell to commence cell division, leading to mitosis. Thus, mitogens can be effectively used to stimulate lymphocytes and therefote assess immune function. By stimulating lymphocytes, mitogens can be used to replicate the effects of a Till -mediated disease, such as a viral infection.

The mitogen that the inventors used to stimulate lymphocytes, and therefore assess immune function, was lipopolysaccharide (LPS), which acts on B cells but not T cells. The effects of embodiments of die compound represented by formula I, i.e. erythro 2-(l,l- dimethylethyl)amiiio-l-(3-chloropheiiyl)propan-l-ol (BC1053), on the levels of IL-10 were investigated in LPS stimulated assays. Peripheral Blood Mononuclear Cells (PMBC) were independently administered with LPS, and then treated with BC1053. Control experiments were conducted in which no LPS was added, such that any effect on the levels of IL10 could be directiy attributed to the presence of the test compound, BC1053. (a) Effect of BC1053 on LPS-induced blood IL-10 levels in mice

Referring to Figure 2, there is shown the effects of different concentrations of BC1053 (3mg/kg, lOmg/kg and 30mg/kg) on the endogenous production levels of IL-10 when measured in vivo. In general, the concentration of IL-10 increases with increasing concentration of BC1053. The fact that the lOmg/kg dosage of BCIO was a little lowet than the 3mg/kg dose may be explained by the effect being maximal at 3 mg/kg, a dose response may well have been defined with lower doses.

(b) Effect of orally dosed BC1053 on ex vivo stimulated IL-10 in murine blood

Referring to Figure 3, there is shown the effects of different concentrations of BC1053 (lOmg/kg, 30mg/kg and 60mg/kg) on the production levels of IL-10 after extracted blood is stimulated with LPS (ex vivo). The concentration of ex vivo stimulated IL-10 increases with increasing concentration of BC1053. (c) In vivo cytokine experiments using LPS induction

Referring to Figure 4, the table shows that BC1053 induces large reduction in TNFa concentrations at all three doses tested (i.e. 3mg/kg, lOmg/kg and 30mg/kg), but that, surprisingly, the concentration of IL-10 significantly increases at all three doses. As can be seen, at the lowest dose of only 3mg/kg BC1053, the concentration of IL-10 increases by 44% compared to the control where no BC1053 was added. The concentration of IL- 0 increases by 56% at the highest dose tested, i.e. 30mg/kg BC1053.

Example 2 - Effect of BC1053 on Dextran sulphate DSS)-induced colitis mice

Figure 5 is a table showing that various different mouse and rat models can be used to represent human disease conditions. For example, (i) septic shock in human can be represented by the lipopolysaccharide (LPS) model in mouse, (ii) rheumatoid arthritis can be represented by the complete Freud's adjuvant induced model in rat, (iii) arthritic swelling can be represented by the carrageenan paw oedema in rat, (iv) inflammatory bowel disease (IBD) can be represented by the dextran sulphate (DSS) and trinitrobenzene sulfonic acid (TNBS) induced colitis model in mice, and multiple sclerosis (MS) can be represented by the proteolipid protein (PLP) induced experimental autoimmune encephalitis model in SJL mice. Referring to Figure 6, there is shown the data generated from carrying out the DSS-induced colitis model for IBD. Two doses of BC1053 (lOmg/kg and 30mg/kg) were administered to the mice, and compared against the control of 0.2mg/kg of the corticosteroid, dexamethasone. The inventors were surprised to see that BC 053 was effective at both doses when assessing lesions and diarrhoea. Overall, these data suggest diat BO053 has a more complete anti-ulcerative and chsease-modifying effect than a well-known strong corticosteroid (dexamethasone), which has previously been used in the treatment of IBD.

Figure 7 illustrates the DSS colitis histology scores, and shows that both the lOmg/kg and 30mg/kg doses of BC 1053 were as effective as the positive control, i.e. dexamethasone.

Example 3 - Effect of BC 1053 on TNBS-induced colitis mice

Figure 8 is a table showing the effects of administering 30mg/kg BC1053 on TNBS- induced mice, as compared to the control of lOmg/kg sulphasalazine (an antibiotic/anti- inflammatory compound) that is commonly used in the treatment of IBD. The inventors demonstrated that BC1053 caused an increase in body weight of the treated mice, more effectively than sulphasalazine. Lesion score and composite clinical scores for BC1053 were comparable or slighu better than the sulphasalazine.

Referring to Figure 9, there is shown the effect of BC1053 on the mean composite clinical score over 8 days compared to sulphasalazine. The inventors were surprised to observe that BC1053 successfully reduced the score over the time period tested. These data demonstrate that BC1053, through the raising of IL-10, has the ability to improve modelled IBD.

Example 4 - Effect of BC1053 on T BS cytokine explants

The inventors then decided to investigate the effect of BC 1053 on the concentrations of the Thl response cytokines, IL-12 and TNFa, and were surprised to observe, in an in mm model, that their concentrations dramatically decreased (see Figures 10 and 11). Based on this observation, the inventors hypothesise that BC1053 can be used to effectively increase endogenous levels of IL-10, thereby promoting the switch from a Thl to a Th2 immune response, while simultaneously decreasing the concentration of the Thl cytokines, such as IL-12 and TNFa (and IFNy).

Example 5 - Effect of BC 1053 on PLP-induced EAE in SJL mice

As shown in Figure 12, the inventors used an established model which is representative of multiple sclerosis. They demonstrated that BC1053 effectively prevents a second relapse, whereas the two controls (untreated mice and mice treated with only the vehicle) did not.

Example 6 - Pessary

The inventors have prepared a delivery device made of a support matrix onto which the lipid-rich BC1053 composition is immobilised, and which can be easily used for treating any Thl -mediated disorder. The delivery device is formed in the shape of a pessary, with a waxy support matrix. Conventional materials for vaginal administration that have been used include glycerol/gelatin, gly co-gelatin, macrogols (polyethylene glycols), natural, synthetic or semi-synthetic hard fats, and fractionated palm kernel oil, each having BC1053 immobilised thereon. The support matrix melts at body temperature, so that, over time, the composition is released and absorbed by the subject.

The inventors are aware that premature labour can be caused in pregnant mothers due to a drop in IL-10 concentrations. Therefore, the pessary can be worn by a pregnant woman, such that the BC1053 formulation is released, resulting in an increase in endogenous IL-10 production, thereby preventing premature labour.

Summary

In summary, the inventors were surprised to observe that compound, BC1053 shown in Figure 1, not only stimulated production of endogenous IL-10 by Th2 cells, macrophages and dendritic cells, but also acted as an effective Thl cytokine inhibitor (i.e. IL-12 and TNF-oc). They therefore believe that any compound represented by formula (I) may be used as an IL-10 stimulator and as an IL-12 and TNF-oc inhibitor, which can be used in the treatment of any Thl -mediated diseases. For example, the results described herein concerning the various established disease models show that BC1053 can be used in the treatment of at least septic shock, rheumatoid arthritis, arthritic swelling, IBD and MS. Indeed, BC1053 has clear effects in the two "difficult" colitis models, and its efficacy is better than dexamethasone, budesonide and sulphasalazine in validated preclinical colitis models.

BC1053 also has novel and surprising effects in the murine EAE model, a T cell driven model. It was shown to treat relapse (i.e. the antigen drive phase), and so this will find utility across a wide range of Thl driven disease states.

Claims

1. A compound which is capable of increasing i terleukin-10 (IL-10) production, for use in treating a Thl -mediated disease, wherein the IL-10 is endogenously produced by Th2 cells, dendritic cells and/ or macrophages.

2. A compound according to claim 1, wherein the compound is used to increase endogenous IL-10 production in a paracrine manner.

3. A compound according to any preceding claim, wherein the compound modulates Thl cytokine concentration, such as IFNy, TNF-a and IL-12.

4. A compound according to any preceding claim, wherein the compound has formula I:-

wherein: -

X is CO, CHOH or CH₂;

R¹ is H, or combined with R²;

R² is H, OH, a halogen, a substituted or unsubstituted amino group, a C _s alkyl or alkoxyl group, optionally substituted with one or more O, OH, amino and/or optionally C_1.3 alkyl substituted phenyl group, or combined with R¹;

R³ and R⁴ are each independently H, OH, a halogen, a substituted or unsubstituted amino group, or a Q.5 alkyl or alkoxyl group, optionally substituted with one or more O, OH, amino and/or optionally C_{1 3} alkyl substituted phenyl group;

R⁵ is H;

R⁶ is H, a C _s alkyl group, or combined with R⁸;

R⁷ is H, or combined with R⁸; R⁸ is combined with R^e or R⁷, or is a straight chain, branched or cyclo- C_rC₉ alkyl group, optionally including one or more heteto atom in its carbon skeleton and optionally substituted with one or more OH, and/or C_{5 6} aryl group, optionally substituted with one or more OH or C,__s alkoxyl or alkyl group;

when combined, R¹ and R², together with the associated ring carbon atoms, form an optionally O substituted cycloalkyl, cycloalkenyl, cycloheteroalkyl or cycloheteroalkenyl group of 5 or 6 carbon atoms, or 4 or 5 carbon atoms and a hetero atom;

when combined, R⁶ and R⁸, together widi the nitrogen atom carrying R⁸ and the carbon atom carrying R^r', form a 5 or 6 membered cycloheteroalkyl group; and,

when combined, R⁷ and R⁸, togedier with the nitrogen atom carrying them, form an optionally benzyl substituted 5 or 6 membered cycloheteroalkyl group;

or a pharmaceutically acceptable salt or solvate thereof.

5. A compound according to claim 4, wherein R² is a hydroxyalkyl group, or a carbonyloxy group and is, preferably, H, OH, HOCH₂-, 0=CHNH-, CH₃PhCOO-,

NH₂COO-, or a halogen, optionally wherein R² is H, OH or CI.

6. A compound according to either claim 4 or 5, wherein R₃ is H, NH₂, OH or CH₃PhCOO-

7. A compound according to any one of claims 4-6, wherein R³ is H, NH₂ or OH.

8. A compound according to any one of claims 4-7, wherein R⁴ is H, OH, NH₂COO-, or a halogen, optionally wherein R⁴ is H or CI.

9. A compound according to any one of claims 4-8, wherein R⁶ is methyl, ethyl, or H.

10. A compound according to any one of claims 4-9, wherein R⁷ is H. 11. A compound according to any one of claims 4-10, wherein R⁸ is a straight chain or branched C₂-C₅ alkyl group, optionally substituted with OH, phenyl, PhOH or PhOCH₃, optionally wherein R⁸ is tert. butyl, isopropyl, -C(CH₃)₂OH, -CH₂PhOCH₃,-(CH₂)₂PhOH, - CH(C¾)CH,CH₂Ph, or -CH(CH₃)CH₂CH₂PhOH. compound according to any one of claims 4-10, wherein R¹

13. A compound according to any one of claims 4-12, wherein when combined, R¹ and 2 form the group:-

14. A compound according to any one of claims 4- 3, wherein when R⁶ and R⁸ are combined, together with the nitrogen atom carrying R⁸ and the carbon atom carrying R⁶, they form a cycloheteroalkyl group of 5 carbon atoms and 1 nitrogen atom.

15. A compound according to any one of claims 4-14, wherein when R⁷ and R⁸ are combined they form the group:-

16. A compound according to any one of claims 4-15, wherein the compound (I) includes any diastereomer and enantiomer of the formula represented by (1). 17. A compound according to any preceding claim, wherein the compound is bupropion or a metabolite thereof.

18. A compound according to claim 17, wherein the bupropion metabolite dimemylemyi) amino- l-(3-chlorophenyI)propan- 1 -ol, 2 (1,1 -dimethyl-2- hydroxye Ayl)amino-l -(3-chlorophenyl)propan-l -one, (1 S,2R)-erythro-2-(l ,1 - dimemylemyl)amino- 1 -(3-chlorophenyl)propan- 1 -ol, (lR,2S)-erythro-2-(i , 1 - dimethylemyl)amino-l -(3-chloiophenyl)ptopan-l -ol, 1 S,2S)-threo-2-(l ,1- dimethylethyl) amino- 1 - (3 -chlorophenyl)propan- -ol, or (1 R,2 ) -threo-2- (1 , 1 - dimethylemyl)amino-l-(3-chlorophenyl)propan-l-ol.

19. A compound according to any one of claims 4-18, wherein the compound defined by formula (I) includes the erythro enantiomer or enantiomers.

20. A compound according to any preceding claim, wherein the Thl -mediated disease, which may be treated, is a Thl -mediated inflammatory disease, preferably systemic inflammatory disease.

21. A compound according to claim 20, wherein compound is used to stimulate endogenous production of IL-10, and reduce Thl cytokine production, and to thereby induce the switch from a Thl to a Th2 response, in such a way so as to be useful in the treatment of Th -mediated inflammatory disease.

22. A compound according to any preceding claim, wherein the Thl -mediated disease to be treated is selected from a group of Thl -mediated diseases consisting of rheumatoid arthritis (RA); psoriatic arthritis; psoriasis; inflammatory bowel syndrome (IBD); Crohn's disease; ulcerative colitis; multiple sclerosis (MS); flu, including pandemic flu; respiratory disorders, for example those caused by viruses, such as respiratory syncytial virus (RSV); cystic fibrosis; herpes, including genital herpes; asthma and allergies; sepsis and septic shock; bacterial pneumonia; bacterial meningitis; dengue hemorrhagic fever; diabetes Type I; endometriosis; prostatitis; uveitis; uterine ripening; age-related macular degeneration; and virally, bacterially or chemically induced Thl -mediated diseases.

23. A compound according to claim 22, wherein the Thl -mediated disease to be treated is inflammatory bowel syndrome (IBD) or rheumatoid arthritis (RA).

24. A pharmaceutical composition comprising a therapeutically effective amount of a compound as defined in any one of claims 1-23, and a pharmaceutically acceptable vehicle, for use in the treatment of a Thl -mediated disease, wherein the IL-10 is endogenously produced by Th2 cells, dendritic cells and/ or macrophages.

25. A drug delivery device comprising: -

(i) a pharmaceutical composition comprising a therapeutically effective amount of a compound which is capable of increasing endogenous interleukin-10 (IL-10) production by Th2 cells, dendritic cells and/or macrophages; and (ii) a support matrix.

26. A drug delivery device according to claim 25, wherein the device comprises the pharmaceutical composition defined in claim 24. 27. A drug delivery device according to either claim 25 or claim 26, wherein the device is a pessary or a vaginal ring, or the like.

28. A drug delivery device according to any one of claims 25 to 27, wherein the device is worn by a subject requiring treatment of a Thl -mediated condition.

29. A drug delivery device according to any one of claims 25 to 28, wherein the delivery device is used by pregnant women to prevent or delay premature labour.

30. A drug delivery device according to any one of claims 25 to 29, wherein the support matrix comprises a material capable of melting at, or around, body temperature, such that, over time, the matrix dissolves thereby releasing the composition, which is absorbed by the subject.

31. A drug delivery device according to any one of claims 25 to 30, wherein the support matrix is a gel or wax, for example glycerol/gelatin, glyco-gelatin, macrogol (e.g.

polyethylene glycol), natural, synthetic or semi-synthetic hard fat, or fractionated palm kernel oil.

32. A method of preventing, treating and / or ameliorating a Th -mediated disease, the method comprising administering, to a subject in need of such treatment, a therapeutically effective amount of a compound as defined in any one claims 1-23.

33. Use of a compound as defined in any one of claims 1 -23, for inducing endogenous production of interkukin-10 (IL-10) by Th2 cells, dendritic cells and/or macrophages, for treating a Th-1 mediated disease.