OA12440A

OA12440A - Histamine receptor antagonists.

Info

Publication number: OA12440A
Application number: OA1200300174A
Authority: OA
Inventors: Stephen Jenkinson; Mark Anthony O'reilly; Michael Andrew Trevethick
Original assignee: Pfizer
Priority date: 2001-01-17
Filing date: 2002-01-10
Publication date: 2006-05-22
Also published as: AP2002002401A0; CN1486178A; EE200300335A; DOP2002000325A; NO20033223D0; CR6983A; SK8572003A3; EP1353657A1; CA2435121A1; IS6818A; JP2004517883A; ECSP034692A; PL362793A1; GT200200003A; SV2003000849A; KR20030069216A; BR0206502A; WO2002056871A2; HUP0302767A2; GB0101223D0

Description

012440 , 1

HISTAMINE RECEPTQR ANTAGONISTS

This invention relates to a combination of a histamine H, receptorantagonist and a sélective histamine H4 receptor antagonist for the treatment of 5 a range of diseases that may be treated by antagonism of either or both of theH1 and H4 receptors including allergie diseases and disorders such as allergierhinitis and asthma, to the uses of, and to compositions, products and methodsof treatment including, such a combination. This invention also relates to asélective histamine H4 receptor antagonist. 10 Allergies are widespread and affect a large proportion of the world population. They may be seasonal in nature and can be caused by a variety offactors présent in the environment such as pollen, mites and dust particles.

Symptoms of allergie rhinitis, which may be seasonal or perennial, caninciude rhinorrhea, nasal congestion and irritation, often accompanied by 15 coughing or sneezing. Irritation and soreness of the throat and eyes is alsocommon. The level of severity of each symptom experienced may vary fromrepresenting a minor problem to a person experiencing a severe effect.

The use of a histamine H1 receptor antagonist in the treatment of allergierhinitis is well-documented but when administered alone it does not provide an 20 effective relief for nasal blockage and such agents are therefore often administered concurrentiy with sympathomimetic amine decongestants such asphenylpropanolamine and pseudoephedrine. However, such concommitanttherapy is not suitable for ail patients since central nervous System andcardiovascular side effects are often observed. WO98/06394 discloses the use 25 of a combination of a histamine H1 receptor antagonist and a histamine H3receptor antagonist for the treatment of allergy-induced responses in themammalian airway, including relief from nasal congestion.

There exists a need for additional effective treatments of allergie diseases and disorders such as allergie rhinitis and asthma. There is a 30 particular need for an alternative therapy to provide relief from most, if not ail, the symptoms of allergie rhinitis, including nasal congestion. 012440 ,- pe

The présent invention is based on the teaching of EP 1096009 A1(Européen Patent Application no. 00309364.8) in which, inter alia, apolynucleotide encoding for a polypeptide corresponding to a G-protein coupiedreceptor (GPCR), newly termed by other researchers the histamine H4 receptor,are described and claimed. Although a compound that antagonises orselectively antagonises such a polypeptide is aiso disciosed in general terms,there is no définition or discussion of the meaning of seiectivity. Further, there isno mention that antagoniste of such a polypeptide may be used in combinationwith a histamine H, receptor antagonist. The teaching of this document isincorporated herein by référencé. In the document the histamine H4 receptor is ζdefined as a polypeptide comprising: (a) a polypeptide having the deduced amino acid sequencetranslated from the polynucleotide sequence in SEQID NO: 1 andvariants, fragments, homologues, analogues and dérivativesthereof; (b) a polypeptide of SEQ ID NO: 2 and variants, fragments,homologues, analogues and dérivatives thereof; or (c) a polypeptide encoded by the cDNA of NCIMB 41073 andvariants, fragments, homologues, analogues and dérivativesthereof.

The définitions of the above terms relating to the polypeptide are to beunderstood to be in conformity with the teaching of EP 1096009 A1 (EuropeanPatent Application no. 00309364.8) and, in particular, the terms "variant", "homologue", "fragment", "analogue" or "dérivative" in relation to the amino acidsequence for the polypeptide indude any substitution of, variation of, modificationof, replacement of, délétion of or addition of one (or more) amino acid from or tothe sequence providing the résultant polypeptide has GPCR activity, preferablybeing at least as biologicaliy active as the polypeptide shown in attached SEQ IDNO: 2. in particular, the term "homologue" covers homology with respect to 012440 3 structure and/or fonction. With respect to sequence homology, there is at least70%, preferably at least 75%, more preferably at least 80%, more preferably atleast 85%, more preferably at least 90%, more preferably at least 95% homologyto the sequence shown in SEQ ID NO: 2. Most preferably there is at least 98%homology to the sequence shown in SEQ ID NO: 2.

This polypeptide corresponds to the orphan G-protein-coupled receptorencoded GPRv53, that has been surmised to be a novel histamine H4 receptor,as described in The Journal of Biological Chemistry, 275(47), 36781-36786(November 2000), the teaching of which is incorporated herein by reference.

We hâve surprisingly found that histamine-induced chemotaxis(migration towards a chemoattractant) of human eosinophils appears to bemediated by the histamine H4 receptor and not by the histamine H3 receptorand therefore that histamine H4 receptor antagonists prevent histamine-inducedchemotaxis of human eosinophils. Eosinophils hâve been impiicated in thepathogenesis of inflammatory and allergie diseases such as asthma andallergie rhinitis and high levels of histamine are released in patients with theseconditions. Histamine H4 receptor antagonists may be advantageously used intreating such conditions since (i) they are likely to inhibit eosinophil infiltrationinto the nose and thus relieve nasal congestion by an additional or independentmechanism to antagonism of the histamine H3 receptor, or (ii) by inhibitingeosinophil infiltration into the lung they are likely to reduce the inflammationassociated with asthma and provide an effective alternative treatment for thisdisease. A combination of a sélective histamine H4 receptor antagonist and ahistamine H, receptor antagonist may be advantageously used to treat allergierhinitis since it wouid treat ail the main symptoms of this disease including nasalcongestion. A combination of a sélective histamine H4 receptor antagonist anda histamine H1 receptor antagonist may be advantageously used to treatasthma since it may improve lung fonction in a synergistic manner. 012440 4

The présent invention provides a combination of (a) a histamine H, receptor antagonist and (b) an antagonist that is at ieast 10-fold sélective for the histamine H4 receptor as compared to the histamine H3 receptor.

The présent invention also provides a combination of (a) a histamine H! 5 receptor antagonist and (b) an antagonist that is at ieast 10-fold seiective for the histamine H4 receptor as compared to the histamine H3 receptor, foradministration simultaneously, separately or sequentially, for use as amédicament for the treatment of a disease or disorder that may be treated byantagonism of either or both of the histamine H1 and H4 receptors such as 10 allergie rhinitis or asthma. ζ )

The présent invention further provides the use of a combination of (a) ahistamine H1 receptor antagonist and (b) an antagonist that is at ieast 10-foldseiective for the histamine K4 receptor as compared to the histamine H3receptor, for administration simultaneously, separately or sequentially, for the 15 manufacture of a médicament for the treatment of a disease or disorder thatmay be treated by antagonism of either or both of the histamine Hd and H4receptors such as allergie rhinitis or asthma.

The présent invention further provides a method of treatment of amammal, including a human being, to treat a disease or disorder that may be 20 treated by antagonism of either or both of the histamine H, and H4 receptorssuch as allergie rhinitis or asthma including simultaneous, separate orsequentia! administration to the mammal of a (a) an effective amount of ahistamine H! receptor antagonist and (b) an effective amount of an antagonistthat is at ieast 10-fold seiective for the histamine H4 receptor as compared to 25 the histamine H3 receptor.

The présent invention further provides a pharmaceutical compositionincluding (a) a histamine Hi receptor antagonist and (b) an antagonist that is atieast 10-fold seiective for the histamine H4 receptor as compared to thehistamine H3 receptor, and a pharmaceutically acceptabîe excipient, diluent or 30 carrier. 012440 5

The présent invention further provides a product containing (a) ahistamine H., receptor antagonist and (b) an antagonist that is at least 10-foldsélective for the histamine H4 receptor as compared to the histamine H3receptor as a combined préparation for simultaneous, separate or sequential 5 use in the treatment of a disease or disorder that may be treated by antagonismof either or both of the histamine H1 and H4 receptors such as allergie rhinitis orasthma.

The présent invention further provides an antagonist that is at least 10-fold sélective for the histamine H4 receptor as compared to the histamine H3 10 receptor, the uses of and compositions and methods of treatment including,such an antagonist. Such a sélective antagonist has not been previouslydescribed and thioperamide and clobenpropit, both of which are histamine H3receptor antagonists, do not dispiay this degree of selectîvity.

The définition “an antagonist that is at least 10-fold sélective for the 15 histamine H4 receptor as compared to the histamine H3 receptor” as used herein means an antagonist that is at least 10-fold sélective for the histamine H4receptor as defined in EP 1096009 A1 (Européen Patent Application no.00309364.8) or as the orphan G-protein-coupied receptor encoded GPRv53 asdisclosed in The Journal of Biological Chemistry, 275(47), 36781-36786 20 (November 2000) as described above, as compared to the known histamine H3receptor, by the biological assays described below.

Preferabîy, the antagonist is at least 30-fold sélective for the histamineH4 receptor as compared to the histamine H3 receptor.

Preferabîy, the antagonist is at least 50-fold sélective for the histamine 25 H4 receptor as compared to the histamine H3 receptor.

Preferabîy, the antagonist is at least 100-fold sélective for the histamine H4 receptor as compared to the histamine H3 receptor.

Preferabîy, the antagonist is at least 1000-fold sélective for the histamine H4 receptor as compared to the histamine H3 receptor. 30 The définition “histamine H, receptor antagonist" is well-understood in the art and is in accordance therewith. 012440 S.

The diseases or disorders that may be treated with the présentcombination or antagonist inciude those which may be modulated byantagonism of the H4 receptor such as those which concern aspects of signaltransduction. Useful therapeutic areas inciude, but are not limited to, obesity,diabètes and metabolic disease, neurological disease, psychotherapeutics,urogénital disease, reproduction and sexual medicine, inflammation, cancer,tissue repair, dermatology, skin pigmentation, photoageing, frailty,osteoporosis, cardiovascular disease, gastrointestinal disease, anti-infection,allergy and respiratory disease, sensory organ disorders, sleep disorders andhairioss. / Ί

Preferred diseases or disorders that may be treated are allergiedisorders such as extrinsic asthma, rhinitis (allergie and chronic), onchocercaldermatitis, atopie dermatitis, drug réactions and NERDS (nodules, eosinophiiia,rheumatism, dermatitis and swelling), vasculitic granulomatous diseases suchas temporal vasculitis, Churg-Strauss syndrome, polyarteritis, Wegner’sgranuiomatosis and éosinophilie granulomatous prostatitis, immunologicaldisorders such as autoimmune reactions (e.g. multiple sclerosis), graft rejectionand intrinsic asthma, interstitial and other pulmonary diseases such as chronicobstructive pulmonary disease (COPD), éosinophilie pleurai effusions, transientpulmonary éosinophilie infiltrâtes (Loffler), histiocytosis, chronic éosinophiliepneumonia, hypersensitivity pneumonitis, allergie bronchopulmonaryaspergillosis, sarcoidosis, idiopathic pulmonary fibrosis and topica! eosinophiiia,infectious parasitic diseases such as toxocariasis, filariasis, schistosomiasis,trichinosis, strongyioides, ascariasis and echinococcosis/cysticercosis, otherinfectious diseases such as acute coccidioidomycosis, cat scratch disease,afebrile tuberculosis and chlamydial pneumonia at infancy, neopiastic and myeloproliferative diseases such as bronchogenic carcinoma, hyperéosinophiliesyndrome, T-cell lymphomas and Hodgkin’s disease, inflammatory conditionssuch as inflammatory bowei diseases (e.g. uicerative colitis, Crohn’s disease)and sinusitis, and coeliac disease, obstructive hepatic disease and dermatitisherpetiformis. 012440 ρζ^·τ /’7

Particularly preferred diseases or disorders that may be treated areselected from the group consisting of asthma (both extrinsic and intrinsic), • rhinitis (allergie and chronic), COPD and infiammatory bowel diseases, or that consisting of allergie disorders, vasculitic granulomatous diseases, 5 immunological disorders, interstitial and other pulmonary diseases, infectiousdiseases, infiammatory diseases, and neopiastic and myeloproliferativediseases. Preferably, said allergie disorder is extrinsic asthma or rhinitis(allergie or chronic), said immunological disorder is intrinsic. asthma, saidpulmonary disease is COPD and said infiammatory diseases are infiammatory 10 bowel diseases.

The selectivity of an antagonist for the histamine H3 or H4 receptor canbe determined by the following procedures.

The cDNA for the human histamine H3 and H4 receptor can beexpressed in a suitable cell line such as HEK293 or CHO. In addition 15 membranes can be prepared from tissues or cells which naturaliy expresseither the histamine H3 and/or H4 receptor. Affinity can be assessed at eitherreceptor by assessing the ability of ligands to inhibit the binding of a suitableradioactively labelled ligand to membranes containing either the histamine H3 orH4 receptor. The potency of compounds is compared by calculating their pK, 20 values.

The functional activity of ligands to détermine agonist or antagonistactivity is determined in whole cells expressing either the K3 or H4 receptor.Agonists (fuli or partial) are identified as agents which inhibit forskolinstimulated cyclic AMP production which can be measured directly (as cyclic 25 AMP) or indirectly as changes in beta-lactamase activity in cells co-expressingthe CRE-beta-lactamase reporter System and the appropriate histaminereceptor. Agonist activities may be expressed as IC50 values. Inverse agonists , can also be identified by the inhibition of the basal cAMP activity (i.e. in the absence of forskolin). Agents which hâve no effect on forskolin stimulated 30 cAMP or inhibit basal cAMP may be antagoniste and such activity can be measured in an assay where cells are pre-incubated with the ligand of interest '· ·Λ« 012440 8 and their abiiity to inhibit H3 or H4 agonist-induced réduction of forskolin stimiilated cyclic AMP is measured as described above. The experiments canbe performed in one of two ways. Firstly, by increasing the concentration ofantagonist versus fixed concentration of agonist and calculating the IC50 foreach antagonist. Secondly, by increasing the concentration of antagonistversus increasing the concentration of agonist and expressing the antagonistpotency as a pkb or pA2 value, as appropriate. A further functionai assay for the histamine H4 receptor détermines theabiiity of histamine to induce chemotaxis in eosinophils isolated from humanblood. In this assay cells are primed with interleukin 5 and the abiiity of ry histaminergic ligands to promote migration of eosinophils across a permeablemembrane is studied. The number of cells migrating in a defmed periad is thencounted. Agonist potencies are expressed as EC50 values. Antagoniste canalso be studied by pre-incubating eosinophils with the compound and thenassessing the inhibitory effects on histamine (or other suitable ligand) oneosinophil chemotaxis. The experiments can be performed in one of two ways.

Firstly, by increasing the concentration of antagonist versus fixed concentrationof agonist and calculating the IC5O for each antagonist. Secondly, by increasingthe concentration of antagonist versus increasing the concentration of agonistand expressing the antagonist potency as a pkb or pA2 value, as appropriate. s'y

Using this assay we hâve shown that histamine-induced chemotaxis of human ' eosinophils appears to be mediated by the histamine H4 receptor and not by thehistamine K3 receptor.

The présent combination (or each active element thereof) or antagonistcan be administered alone but will generally be administered in admixture witha suitable pharmaceutical excipient, diluent or carrier selected with regard tothe intended route of administration and standard pharmaceutical practice.

For example, the présent combination or antagonist can be administered orally, buccally or subiinguaily in the form of tablets, capsules, multi- particulates, gels, films, ovules, élixirs, solutions or suspensions, which may contain flavouring or colouring agents, for immédiate-, delayed-, modified-, Q12440 pÇTIIR/>~ 9 sustained-, pulsed- or controlled-release applications. The présent combinationor antagonist may also be administered as fast-dispersing or fast-dissolvingdosage forms or in the form of a high energy dispersion or as coated particles.Suitable formulations of the présent combination or antagonist may be incoated or uncoated form, as desired.

Such solid pharmaceutical compositions, for example, tablets, maycontain excipients such as microcrystalline cellulose, lactose, sodium citrate,calcium carbonate, dibasic calcium phosphate, glycine and starch (preferablycorn, potato or tapioca starch), disintegrants such as sodium starch glycollate,croscarmellose sodium and certain complex silicates, and granulation binderssuch as polyvinylpyrroiidone, hydroxypropylmethylcellulose (HPMC),hydroxypropylcellulose (HPC), sucrose, gelatin and acacia. Additionaily,lubricating agents such as magnésium stéarate, stearic acid, glyceryl behenateand talc may be included.

General Example A formulation of a tablet couîd typically contain from 0.01 mg to 500mg of eachactive element of the combination or of the antagonist whilst tablet fill weightsmay range from 50mg to 1000mg. An example of a formulation for a 10mgtablet is iliustrated below:

Ingrédient %w/w

Pharmaceutically active agent(s) 10.000*

Lactose 64.125

Starch 21.375

Croscarmellose sodium 3.000

Magnésium Stéarate 1.500 * Quantity adjusted in accordance with drug activity. 01 2440 ... 10

The tablets are manufacturée} by a standard process, for example, directcompression or a wet or dry granulation process. The tablet cores may becoated with appropriate overcoats.

Soiid compositions of a similar type may aiso be employed as filière in 5 gelatin or HPMC capsules. Preferred excipients in this regard include lactose,starch, a cellulose, milk sugar or high molecular weight polyethylene glycols.

For aqueous suspensions and/or élixirs, the présent combination or antagonistmay be combined with various sweetening or flavouring agents, colouringmatter or dyes, with emulsifying and/or suspending agents and with diluents 10 such as water, éthanol, propylene glycol and glycerin, and combinations θ thereof.

The présent combination or antagonist can also be administeredparenterally, for exampie, intravenously, intra-arterialiy, intraperitonealiy,intrathecally, intraventricuiarly, intraurethrally, intrastemally, intracranially, 15 intramuscularly or subeutaneousiy, or they may be administered by infusion orneedleless injection techniques. For such parentéral administration they arebest used in the form of a stérile aqueous solution which may contain othersubstances, for examplé, enough salis or glucose to make the solution isotoniewith blood. The aqueous solutions shouid be suitabiy buffered (preferabiy to a 20 pH of from 3 to 9), if necessary. The préparation of suitable parentéralformulations under stérile conditions is readily accomplished by standardpharmaceutical techniques well-known to those skilled in the art.

For oral and parentéral administration to human patients, the daiiydosage ievel of each active element of the présent combination or of the 25 présent antagonist will usually be from 0.01 to 50mg/kg body weight of thesubject to be treated, preferabiy from 0.1 to 20mg/kg (in single or divideddoses), or they may be administered by intravenous infusion at a dose of from0.001 to 10mg/kg/hour.

For oral, parentéral, buccal or sublingual administration to a subject to be 30 treated, the daily dosage Ievel of each active element of the combination or ofthe antagonist may typically be from 10 to 500mg (in single or divided doses). 012440

Thus tablets or capsules of the présent combination or antagonist may containfrom 5 to 100mg of each active element of the combination or of the antagonistfor administration singly or two or more at a time, as appropriate. The physicianin any event will détermine the actual dosage which will be most suitabie for 5 any individual patient and it will vary with the âge, weight and response of theparticular patient. The above dosages are exemplary of the average case.

There can, of course, be individual instances where higher or lower dosageranges are merited and such are within the scope of this invention.

The présent combination or antagonist can also be administeredθ 10 intranasally or by inhalation and are convenientiy deiivered in the form of a dry powder inhaler or an aérosol spray présentation from a pressurised container,pump, spray, atomiser or nebuliser, with or without the use of a suitabiepropellant, e.g. dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, a hydrofluoroalkane such as 1,1,1,2- 15 tetrafluoroethane (HFA 134A [trade mark]) or 1,1,1,2,3,3,3-heptafluoropropane(HFA 227EA [trade mark]), carbon dioxide or other suitabie gas. In the case ofa pressurised aérosol, the dosage unit may be determined by providing a valveto deliver a metered amount. The pressurised container, pump, spray, atomiseror nebuliser may contain a solution or suspension of the active compound(s), 20 e.g. using a mixture of éthanol and the propellant as the solvent, which mayadditionally contain a lubricant, e.g. sorbitan trioleate. Capsules and cartridges(made, for example, from gelatin) for use in an inhaler or insufflator may beformulated to contain a powder mix of the présent combination or antagonistand a suitabie powder base such as lactose or starch. 25 Aérosol or dry powder formulations are preferably arranged so that each metered dose or “puff” contains from 10pg to 1 mg of each active element of theprésent combination or antagonist for deiivery to the patient. The overall daily „ dose with an aérosol will be in the range of from 10pg to 10mg of each active element of the présent combination or antagonist which may be administered in 30 a single dose or, more usually, in divided doses throughout the day. 012440 .

OC 12

Altematively, the présent combination or antagonist can be administeredin the form of a suppository or pessary, or they may be appiied topically in theform of a gel, hydrogel, lotion, solution, cream, ointment or dusting powder.

The présent combination or antagonist may also be dermally or transdermally 5 administered, for example, by the use of a skin patch. They may aiso beadministered by the puimonary or rectal routes.

They may also be administered by the ocular route, particularly fortreating allergie conditions of the eye. For ophthalmic use, the compounds canbe formulated as micronised suspensions in isotonie, pH adjusted, stérile

10 saline, or, preferably, as solutions in isotonie, pH adjusted, stérile saline, O optionally in combination with a preservative such as a benzylalkoniumchloride. Altematively, they may be formulated in an ointment such aspetrolatum.

For application topically to the skin, the présent combination or 15 antagonist can be formulated as a suitable ointment containing the activecompound(s) suspended or dissolved in, for example, a mixture with one ormore of the following: minerai oil, liquid petrolatum, white petrolatum, propyleneglycol, polyoxyethylene polyoxypropylene compound, emulsifying wax andwater. Altematively, they can be formulated as a suitable lotion or cream, 20 suspended or dissolved in, for example, a mixture of one or more of thefollowing: minerai oil, sorbitan monostearate, a polyethylene glycol, liquidparaffin, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol,benzyl alcohol and water.

Each element of the présent combination or the présent antagonist may 25 also be used in combination with a cyclodextrin. Cyciodextrins are known toform inclusion and non-inclusion complexes with drug moiecules. Formation ofa drug-cyclodextrin complex may modifÿ the solubility, dissolution rate,bioavailability and/or stability property of a drug molécule. Drug-cyclodextrincomplexes are generally useful for most dosage forms and administration 30 routes. As an alternative to direct complexation with the drug the cyclodextrinmay be used as an auxiliary additive, e.g. as a carrer, diluent or solubiliser. ο \ 012440 13 ) 1θ

Alpha-, beta- and gamma-cyclodextrins are most commonly used and suitableexamples are described in WO-A-91/11172, WO-A-94/02518 and WO-A-98/55148.

The présent invention embraces any other suitable formulations andadministration routes described in EP 1096009 A1 (European PatentApplication no. 00309364.8).

The présent combination or antagonist can also be administeredtogether with a steroid, a beta-adrenoceptor agonist, a muscarinic antagonist ora mucolytic.

The présent combination, antagonist or composition can be used to treatthe above-mentioned conditions in humans or in other animais.

It is to be appreciated that ali references herein to treatment includecurative, palliative and prophylactic treatment. 012440 14

PHARMACOLOGiCAL DATA a) Seiectivity of antagoniste for the histamine H, and Ha receptors 5 WO98/06394 discloses histamine H3 receptor antagoniste including thioperamide and clobenpropit without mention of any antagonist activity for thehistamine H4 receptor.

Thioperamide, clobenpropit and iodophenpropit were tested for (i) bindingaffinity for the histamine H4 receptor using the method described on page 7 10 using the HEK293 cell line, and (ii) binding affinity for the histamine H3 receptorusing the method described on page 7 using human brain tissue whichnaturaliy expresses the histamine H3 receptor. The results are shown below.

Compound_l-b binding affinity (pKi) 15

Thioperamide 7.26 +/- 0.06 H? binding affinity (pKi) 6.79 +/-0.10

Clobenpropit 8.18+/-0.02 8.63 +/- 0.04 20 Iodophenpropit 7.87 +/- 0.04 7.94+/-0.10 (A différence of 1.0 iog. unit would indicate a 10-foid seiectivity for the receptorfor which the highest pKi value was obtained) 25

These data clearly show that thioperamide, ciobenpropit and iodophenpropit are both histamine H3 and H4 receptor antagonists but hâve littte seiectivity for the histamine H4 receptor over the histamine H3 receptor. They are certainiy not 10-fold sélective. 0124 4,0 15 b) Histamine-induced chemotaxis of human eosinophils

Using the interleukïn 5 priming method of page 8 it was demonstrated thathistamine promoted chemotaxis of human isolated eosinophils over a 5 concentration range of W8 to 10‘5 M. However, agonists individually sélectivefor the Hi (HTMT), H2 (dimaprit) and H3 (imetit) receptors each did not promotechemotaxis of human eosinophils at concentrations of from 10‘8 to 10‘5 M. 10 Using the eosinophil pre-incubation method of page 8 it was demonstrated thatthe non-selective H4/H3 antagonists thioperamide maleate and clobenpropitdihydrobromide inhibited histamine-induced chemotaxis of human eosinophilsin a concentration related mannerwith IC50S of 0.83 and 1.50 micromoiar,respectively. In contrast antagonists individually sélective for the H1 receptor 15 (mepyramine maleate) and the H2 receptor (cimetidine) had little or no effect onhistamine-induced chemotaxis at concentrations of 10 micromoiar.

These data show that histamine-induced chemotaxis of human eosinophils 20 must be mediated by activation of the histamine H4 receptor. As suchhistamine H4 receptor antagonists may be advantageously used in treatingasthma and allergie rhinitis since (i) they are likely to inhibit eosinophilinfiltration into the nose and thus relieve nasal congestion by an additional orindependent mechanism to antagonism of the histamine H3 receptor, or (ii) by 25 inhibiting eosinophil infiltration into the lung they are likely to reduce theinflammation associated with asthma and provide an effective alternativetreatment for this disease. A combination of a sélective histamine H4 receptorantagonist and a histamine H1 receptor antagonist may therefore beadvantageously used to treat allergie rhinitis since it would treat ail the main 30 symptoms of this disease including nasal congestion. A combination of a sélective histamine H4 receptor antagonist and a histamine H1 receptor 012440 antagonist may also be advantageously used to treat asthma since it may improve lung function in a synergistic manner. 16

Claims

012440 17 CLAiMS

1. A combination of (a) a histamine H1 receptor antagonist and (b) anantagonist that is at least 10-fold sélective forthe histamine H4 receptor ascompared to the histamine H3 receptor.
2. A combination of (a) a histamine H., receptor antagonist and (b) anantagonist that is at ieast 10-fold sélective for the histamine H4 receptor ascompared to the histamine Hs receptor, for use as a médicament.
3. A combination of (a) a histamine H, receptor antagonist and (b) anantagonist that is at least 10-fold sélective for the histamine H4 receptor ascompared to the histamine Hs receptor, for administration simultaneously,separately or sequentially, for use as a médicament for the treatment of adisease or disorder that may be treaied by antagonism of either or both ofthe histamine HA and H4 receptors such as allergie rhinitis or asthma.
4. The use of a combination of (a) a histamine H1 receptor antagonist and (b)an antagonist that is at least 10-fold sélective forthe histamine H4 receptoras compared to the histamine H3 receptor, for administration simultaneously,separately or sequentially, for the manufacture of a médicament for thetreatment of a disease or disorder that may be treated by antagonism ofeither or both of the histamine H1 and H4 receptors such as allergie rhinitis orasthma. 012440.·. 18
5. A pharmaceutical composition including (a) a histamine H, reeeptorantagonist and (b) an antagonist that is at least 10-fold sélective for thehistamine H4 reeeptor as compared to the histamine H3 reeeptor, and apharmaceutically acceptable excipient, diluent or carrier.
6. A product containing (a) a histamine H1 reeeptor antagonist and (b) anantagonist that is at least 10-fold sélective for the histamine H4 reeeptor as θcompared to the histamine H3 reeeptor as a combined préparation for simultaneous, separate or sequential use in the treatment of a disease or disorder that may be treated by antagonism of either or both of thehistamine Ηη and H4 receptors sueh as allergie rhinitis or asthma.
7. An antagonist that is at least 10-fold sélective for the histamine H4 reeeptoras compared to the histamine H3 reeeptor.
8. A pharmaceutical composition including an antagonist as claimed in daim 7and a pharmaceutically acceptable excipient, diluent or carrier. CJ)
9. An antagonist as claimed in daim 7 or composition as claimed in claim 8 foruse as a médicament.
10. An antagonist as claimed in daim 7 or composition as claimed in daim 8 foruse as a médicament for the treatment of a disease or disorder that may be ' treated by antagonism of the histamine K4 reeeptor such as allergie rhinitisor asthma.
11. The use of an antagonist as claimed in daim 7 or a composition as claimed in daim 8 for the manufacture of a médicament for the treatment of a disease or disorder that may be treated by antagonism of the histamine H4 reeeptor such as allergie rhinitis or asthma.