AU2003242895A1

AU2003242895A1 - Combination of PDE5 inhibitors with angiotensin II receptor antagonists

Info

Publication number: AU2003242895A1
Application number: AU2003242895A
Authority: AU
Inventors: David Nathan Abraham Fox; Bernadette Hughes
Original assignee: Pfizer Inc
Current assignee: Pfizer Inc
Priority date: 2002-06-26
Filing date: 2003-06-16
Publication date: 2004-01-19
Also published as: WO2004002461A2; GT200300124A; JP2005531627A; PE20040868A1; GB0214784D0; KR20050013156A; ZA200409532B; PL375079A1; NO20050400L; EP1524996A2; MXPA04012569A; CN1662257A; CA2491002A1; RU2004136276A; WO2004002461A3; PA8575501A1; UY27863A1; BR0312030A; TW200404546A; AR040337A1

Description

WO 2004/002461 PCT/IB2003/002657 1 Novel Combination The invention relates to a combination of a) an inhibitor of cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5) and b) an 5 angiotensin 11 receptor antagonist and particularly the use of such a combination for treating hypertension. Blood pressure (BP) is defined by a number of haemodynamic parameters taken either in isolation or in combination. Systolic blood pressure (SBP) is the peak 10 arterial pressure attained as the heart contracts. Diastolic blood pressure is the minimum arterial pressure attained as the heart relaxes. The difference between the SBP and the DBP is defined as the pulse pressure (PP). Hypertension, or elevated BP, has been defined as a SBP of at least 140mmHg 15 and/or a DBP of at least 90mmHg. By this definition, the prevalence of hypertension in developed countries is about 20% of the adult population, rising to about 60-70% of those aged 60 or more, although a significant fraction of these hypertensive subjects have normal BP when this is measured in a non-clinical setting. Some 60% of this older hypertensive population have isolated systolic hypertension (ISH), 20 i.e. they have an elevated SBP and a normal DBP. Hypertension is associated with an increased risk of stroke, myocardial infarction, atrial fibrillation, heart failure, peripheral vascular disease and renal impairment (Fagard, RH; Am. J. Geriatric Cardiology 11(1), 23-28, 2002; Brown, MJ and Haycock, S; Drugs 59(Suppl 2), 1-12, 2000). 25 The pathophysiology of hypertension is the subject of continuing debate. While it is generally agreed that hypertension is the result of an imbalance between cardiac output and peripheral vascular resistance, and that most hypertensive subjects have abnormal cardiac output and increased peripheral resistance there is uncertainty 30 which parameter changes first (Beevers, G et aL.; BMJ 322, 912-916, 2001).

WO 2004/002461 PCT/IB2003/002657 2 Despite the large number of drugs available in various pharmacological categories, including diuretics, alpha-adrenergic antagonists, beta-adrenergic antagonists, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor antagonists, the need for an effective treatment of 5 hypertension is still not satisfied. Angiotensin Il receptor antagonists (angiotensin receptor blockers, ARBs), which block the vasoconstrictive action of the renin-angiotensin-aldosterone system, are generally considered to be more selective than angiotensin converting enzyme 10 inhibitors, which work on the same physiological pathway, and to produce fewer side effects. Phosphodiesterase type 5 (PDE5) is a cyclic guanosine monophosphate (cGMP) specific phosphodiesterase. Inhibitors of PDE5 decrease the rate of hydrolysis of 15 cGMP and so potentiate the actions of nitric oxide. They have been suggested as antihypertensive agents but have not yet been adopted as therapeutic agents in this field. They are, however, useful in the treatment of male erectile dysfunction. According to a first aspect, the present invention provides the use of a combination 20 comprising a) a PDE5 inhibitor and b) an angiotensin 11 receptor antagonist in the manufacture of a medicament for treating diseases, particularly cardiovascular and metabolic diseases, more particularly hypertension. As used herein, the terms "treating" and "treatment" include palliative, curative and 25 prophylactic treatment. The term "hypertension" includes all diseases characterised by supranormal blood pressure, such as essential hypertension, pulmonary hypertension, secondary hypertension, isolated systolic hypertension, hypertension associated with diabetes, hypertension associated with atherosclerosis, and renovascular hypertension, and further extends to conditions for which elevated 30 blood pressure is a known risk factor. Accordingly, the term "treatment of hypertension" includes the treatment or prevention of complications arising from - WO 2004/002461 PCT/IB2003/002657 3 hypertension, and other associated co-morbidities, including congestive heart failure, angina, stroke, glaucoma and impaired renal function, including renal failure. Metabolic diseases include in particular metabolic syndrome (also known as syndrome X), diabetes and impaired glucose tolerance, including complications 5 thereof, such as diabetic retinopathy and diabetic neuropathy. Hereinafter combinations of a PDE5 inhibitor and an angiotensin 11 receptor antagonist, including combinations of specific PDE5 inhibitors and specific angiotensin II receptor antagonists, will be referred to as combinations of the 10 invention. The combinations of the invention have the advantage that they are more potent, less toxic or have other more desirable properties than PDE5 inhibitors or angiotensin Il receptor antagonists when used alone for treating hypertension. 15 Hereinafter the term "the PDE5 inhibitor" means a PDE5 inhibitor for use in the invention, including all pharmaceutically acceptable salts, solvates and polymorphs of that PDE5 inhibitor. Similarly, the term the term "the angiotensin II receptor antagonist" means an angiotensin Il receptor antagonist for use in the invention, 20 including all pharmaceutically acceptable salts, solvates and polymorphs of that angiotensin il receptor antagonist. The suitability of the PDE5 inhibitor and the angiotensin Il receptor antagonist can be readily determined by evaluation of their potency and selectivity using literature 25 methods followed by evaluation of their toxicity, pharmacokinetics (absorption, metabolism, distribution and elimination), etc in accordance with standard pharmaceutical practice. Suitable compounds are those that are potent and selective, have no significant toxic effect at the therapeutic dose, and preferably are bioavailable following oral administration. 30 WO 2004/002461 PCT/IB2003/002657 4 Potency can be defined as an IC50 value, being the concentration of compound necessary to inhibit the enzyme activity by 50%. IC50 values for the PDE5 inhibitors may be determined using the PDE5 assay in the Test Methods Section hereinafter. Preferably, the PDE5 inhibitors have an IC50 against the PDE5 enzyme of less than 5 1OOnM, more preferably less than 5OnM. Selectivity ratios may readily be determined by the skilled person, by ratio of corresponding IC5o values for the particular enzymes concerned. ICao values for the PDE3 and PDE4 enzyme may be determined using established literature 10 methodology, see Ballard SA et al.; Journal of Urology 159, 2164-2171, 1998. Preferably the PDE5 inhibitors are selective for the PDE5 enzyme. Preferably they have a selectivity for PDE5 over PDE3 of greater than 100, more preferably greater than 300. More preferably the PDE5 has a selectivity over both PDE3 and PDE4 of 15 greater than 100, more preferably greater than 300. Preferably the PDE5 inhibitors have an IC50 against PDE5 of less than 1 OOnM and a selectivity over PDE3 of greater than 100 fold. 20 Oral bioavailablity refers to the proportion of an orally administered drug that reaches the systemic circulation. The factors that determine oral bioavailability of a drug are dissolution, membrane permeability and hepatic clearance. Typically, a screening cascade of firstly in vitro and then in vivo techniques is used to determine oral bioavailablity. 25 Dissolution, the solubilisation of the drug by the aqueous contents of the gastro intestinal tract (GIT), can be predicted from in vitro solubility experiments conducted at appropriate pH to mimic the GIT. Preferably the PDE5 inhibitors have a minimum solubility of 50 tg/ml. Solubility can be determined by standard procedures known in 30 the art such as described in Lipinski CA et al.; Adv. Drug Deliv. Rev. 23(1-3), 3-25, 1997.

WO 2004/002461 PCT/IB2003/002657 5 Membrane permeability refers to the passage of a compound through the cells of the GIT. Lipophilicity is a key property in predicting this and is determined by in vitro Log D 7

.

4 measurements using organic solvents and buffer. Preferably the PDE5 5 inhibitors have a Log D 7

.

4 of -2 to +4, more preferably -1 to +3. The Log D can be determined by standard procedures known in the art such as described in Stopher, D and McClean, S; J. Pharm. Pharmacol. 42(2), 144,1990. Cell monolayer assays such as Caco2 add substantially to prediction of favourable 10 membrane permeability in the presence of efflux transporters such as P-glycoprotein, so-called Caco2 flux. Preferably, the PDE5 inhibitors have a Caco2 flux of greater than 2x1 0 6 cm.s- 1 , more preferably greater than 5x1 0- 6 cm.s- 1 . The Caco2 flux value can be determined by standard procedures known in the art such as described in Artursson, P and Magnusson, C; J. Pharm. Sci, 79(7), 595-600, 15 1990. Metabolic stability addresses the ability of the GIT to metabolise compounds during the absorption process or the liver to do so immediately post-absorption: the first pass effect. Assay systems such as microsomes, hepatocytes etc are predictive of 20 metabolic lability. Preferably the PDE5 inhibitors show metabolic stability in the assay system that is commensurate with an hepatic extraction of less then 0.5. Examples of assay systems and data manipulation are described in Obach, RS; Curr. Opin. Drug Disc. Devel. 4(1), 36-44, 2001 and Shibata, Y et al.; Drug Met. Disp. 28(12), 1518-1523, 2000. 25 Because of the interplay of the above processes, further support that a drug will be orally bioavailable in humans can be gained by in vivo experiments in animals. Absolute bioavailability is determined in these studies by administering the compound separately or in mixtures by the oral route. For absolute determinations 30 (% orally bioavailable) the intravenous route is also employed. Examples of the assessment of oral bioavailability in animals can be found in Ward, KW et aL.; Drug WO 2004/002461 PCT/IB2003/002657 6 Met. Disp. 29(1), 82-87, 2001; Berman, J et al.; J. Med. Chem. 40(6), 827-829, 1997 and Han KS and Lee, MG; Drug Met. Disp. 27(2), 221-226, 1999. Examples of PDE5 inhibitors for use with the invention are: 5 The pyrazolo[4,3-d]pyrimidin-7-ones disclosed in EP-A-0463756, EP-A-0526004 and published international patent applications WO 93/06104, WO 98/49166, WO 99/54333, WO 00/24745, WO 00/27848, WO 01/27112, WO 01/98304 and WO 01/27113; the pyrazolo[3,4-dlpyrimidin-4-ones disclosed in EP-A-0995750, EP-A 10 0995751 and published international patent application WO 93/07149; the pyrazolo[4,3-djpyrimidines disclosed in published international patent applications WO 01/18004, WO 02/00660 and WO 02/59126; the quinazolin-4-ones disclosed in published international patent application WO 93/12095; the pyrido[3,2-d]pyrimidin 4-ones disclosed in published international patent application WO 94/05661; the 15 purin-6-ones disclosed in EP-A-1 092718 and in published international patent application WO 94/00453; the hexahydropyrazino[2',1':6,1]pyrido[3,4-b]indole-1,4 diones disclosed in published international application WO 95/19978; the imidazo[5,1 -j[1,2,4]triazin-ones disclosed in EP-A-1 092719 and in published international application WO 99/24433; the bicyclic compounds disclosed in 20 published international application WO 93/07124 and the imidazoquinazolinones disclosed in Rotella DP et al; J. Med. Chem. 43(7), 1257-1263, 2000. The contents of the published patent applications and journal articles and in particular the general formulae of the therapeutically active compounds of the claims 25 and exemplified compounds therein are incorporated herein in their entirety by reference thereto. Still further examples of PDE5 inhibitors for use with the invention include: 4-bromo 5-(pyridylmethylamino)-6-[3-(4-chlorophenyl)-propoxy]-3(2H)pyridazinone; 1-[4-[(1,3 30 benzodioxol-5- ylmethyl)amiono]-6-chloro-2-quinozolinyl]-4-piperidine-carboxylic acid, monosodium salt; (+)-cis-5,6a,7,9,9,9a-hexahydro-2-[4-(trifluoromethyl)- WO 2004/002461 PCT/IB2003/002657 7 phenylmethyl-5-methyl-cyclopent-4,5]imidazo[2,1-b]purin-4(3H)one; furaziocillin; cis 2-hexyl-5-methyl-3,4,5,6a,7,8,9,9a- octahydrocyclopent[4,5]-imidazo[2,1-b]purin-4 one; 3-acetyl-1-(2-chlorobenzyl)-2-propylindole-6-carboxylate; 3-acetyl-1-(2 chlorobenzyl)-2-propyl indole-6-carboxylate; 4-bromo-5-(3-pyridylmethylamino)-6-(3 5 (4-chlorophenyl) propoxy)-3-(2H)pyridazinone; I-methyl-5(5-morpholinoacetyl-2-n propoxyphenyl)-3-n-propyl-1,6-dihydro-7H-pyrazolo(4,3-d)pyrimidin-7-one; 1-[4-[(1,3 benzodioxol-5-ylmethyl)arnino]-6-chloro-2- quinazolinyl]-4-piperidinecarboxylic acid, monosodium salt; Pharmaprojects No. 4516 (Glaxo Wellcome); Pharmaprojects No. 5051 (Bayer); Pharmaprojects No. 5064 (Kyowa Hakko; see WO 96/26940); 10 Pharmaprojects No. 5069 (Schering Plough); GF-1 96960 (Glaxo Wellcome); E-8010 and E-401 0 (Eisai); Bay-38-3045 & 38-9456 (Bayer) and Sch-51 866. Preferred PDE5 inhibitors for use with the invention include: 15 5-[2-ethoxy-5-(4-methyl-1 -piperazinylsulphony)phenyl]-1 -methyl-3-n-propyl-1,6 dihydro-7H-pyrazolo[4,3-dpyrimidin-7-one (sildenafil) also known as 1-[[3-(6,7 dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4 ethoxyphenyl]sulphonyll-4-methylpiperazine (see EP-A-0463756); 20 5-(2-ethoxy-5-morpholinoacetylphenyl)-1 -methyl-3-n-propyl-1,6-dihydro-7H pyrazolo[4,3-d]pyrimidin-7-one (see EP-A-0526004); 3-ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-n-propoxyphenyl]-2-(pyridin-2 yl)methyl-2,6-dihydro-7H-pyrazolo[4,3-djpyrimidin-7-one (see W098/49166); 25 3-ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(2-methoxyethoxy)pyridin-3-y]-2 (pyridin-2-yl)methyl-2,6-dihydro-7H-pyrazolo[4,3-dpyrimidin-7-one (see W099/54333); 30 (+)-3-ethyl-5-[5-(4-ethylpiperazin-1 -ylsulphonyl)-2-(2-methoxy-1 (R) methylethoxy)pyridin-3-yl]-2-methyl-2,6-dihydro-7H-pyrazolo[4,3-dJpyrimidin-7-one, WO 2004/002461 PCT/IB2003/002657 8 also known as 3-ethyl-5-{5-[4-ethylpiperazin-1 -ylsulphonyl]-2-([(1 R)-2-methoxy-1 methylethyl]oxy)pyridin-3-yl}-2-methyl-2,6-dihydro-7H-pyrazolo[4,3-dlpyrimidin-7-one (see W099/54333); 5 5-[2-ethoxy-5-(4-ethylpiperazin- 1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-methoxyethyl] 2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, also known as 1-{6-ethoxy-5-[3 ethyl-6,7-dihydro-2-(2-methoxyethyl)-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-3 pyridylsulphonyl}-4-ethylpiperazine (see WO 01/27113, Example 8); 10 5-[2-iso-butoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-(1 methylpiperidin-4-yl)-2,6-dihydro-7H-pyrazolo[4,3-dJpyrimidin-7-one (see WO 01/27113, Example 15); 5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-phenyl-2,6 15 dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (see WO 01/27113, Example 66); 5-(5-acetyl-2-propoxy-3-pyridinyl)-3-ethyl-2-(1 -isopropyl-3-azetidinyl)-2,6-dihydro-7H pyrazolo[4,3-djpyrimidin-7-one (see WO 01/27112, Example 124); 20 5-(5-acetyl-2-butoxy-3-pyridinyl)-3-ethyl-2-(1 -ethyl-3-azetidinyl)-2,6-dihydro-7H pyrazolo[4,3-d]pyrimidin-7-one (see WO 01/27112, Example 132); (6R,12aR)-2,3,6,7,12,1 2a-hexahydro-2-methyl-6-(3,4-methylenedioxyphenyl) pyrazino[2', 1':6,1 ]pyrido[3,4-b]indole- 1,4-dione (tadalafil, IC-351), i.e. the compound 25 of examples 78 and 95 of published international application WO95/19978, as well as the compound of examples 1, 3, 7 and 8; 2-[2-ethoxy-5-(4-ethyl-piperazin-1 -yl-1 -sulphonyl)-phenyl]-5-methyl-7-propyl-3H imidazo[5,1-I][1,2,4]triazin-4-one (vardenafil) also known as 1-[[3-(3,4-dihydro-5 30 methyl-4-oxo-7-propylimidazo[5,1 -fj-as-triazin-2-yl)-4-ethoxyphenyl]sulphonyl]-4- WO 2004/002461 PCT/IB2003/002657 9 ethylpiperazine, i.e. the compound of examples 20, 19, 337 and 336 of published international application W099/24433; [7-(3-chloro-4-methoxybenzylamino)-1 -methyl-3-propyl-1 H-pyrazolo[4,3-dlpyrimidin 5 5-ylmethoxy]acetic acid (see WO 02/59126, Example 1); 3-(1 -methyl-7-oxo-3-propyl-6,7-dihydro-1 H-pyrazolo[4,3-d]pyrimidin-5-yl)-N-(2-(1 methylpyrrolidin-2-yl)ethyl)-4-propoxybenzenesulphonamide (see WO 00/27848, Example 68); 10 4-(4-chlorobenzyl)amino-6,7,8-trimethoxyquinazoline (example 11 of published international application W093/07124 (EISAI)); and 7,8-dihydro-8-oxo-6-[2-propoxyphenyl]-1 H-imidazo[4,5-g]quinazoline and 1-[3-[1-[(4 15 fluorophenyl)methyl]-7,8-dihydro-8-oxo-1 H-imidazo[4,5-g]quinazolin-6-y]-4 propoxyphenyl]carboxamide (compounds 3 and 14 from Rotella DP et al; J. Med. Chem. 43(7), 1257-1263, 2000). More preferred PDE5 inhibitors for use with the invention are selected from the 20 group and pharmaceutically acceptable salts thereof: 5-[2-ethoxy-5-(4-methyl-1 -piperazinylsulphonyl)phenyl]- 1 -methyl-3-n-propyl- 1,6 dihydro-7H-pyrazolo[4,3-djpyrimidin-7-one (sildenafil); (6R,12aR)-2,3,6,7,12,12a-hexahydro-2-methyl-6-(3,4-methylenedioxyphenyl) pyrazino[2', 1':6,1 ]pyrido[3,4-b]indole-1,4-dione (tadalafil, IC-351); 25 2-[2-ethoxy-5-(4-ethyl-piperazin-1 -yl-1 -sulphonyl)-phenyl]-5-methyl-7-propyl-3H imidazo[5,1-fj[1,2,4]triazin-4-one (vardenafil); 3-(1 -methyl-7-oxo-3-propyl-6,7-dihydro-1 H-pyrazolo[4,3-d]pyrimidin-5-yl)-N-(2-(1 methylpyrrolidin-2-yl)ethyl)-4-propoxybenzenesulphonamide; 5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2-methoxyethyl] 30 2,6-dihydro-7H-pyrazolo[4,3-djpyrimidin-7-one; and WO 2004/002461 PCT/IB2003/002657 10 5-(5-acetyl-2-butoxy-3-pyridinyl)-3-ethyl-2-(1 -ethyl-3-azetidinyl)-2,6-dihydro-7H pyrazolo[4,3-djpyrimidin-7-one. A particularly preferred PDE5 inhibitor is 5-[2-ethoxy-5-(4-methyl-1 5 piperazinylsulphonyl)phenyl]-1 -methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3 djpyrimidin-7-one (sildenaf il) (also known as 1-[[3-(6,7-dihydro-1 -methyl-7-oxo-3 propyl-1 H-pyrazolo[4,3-d]pyrimidin-5-yI)-4-ethoxyphenyl]sulphony]-4 methylpiperazine) and pharmaceutically acceptable salts thereof. Sildenafil citrate is a preferred salt. 10 Examples of angiotensin il receptor antagonists for use with the invention include candesartan, eprosartan, irbesartan, losartan, olmesartan, olmesartan medoxomil, saralasin, telmisartan and valsartan. 15 Preferred combinations of PDE5 inhibitors and angiotensin Il receptor antagonists for treating hypertension are: sildenafil and candesartan; sidenafil and eprosartan; 20 sildenafil and irbesartan; sildenafil and losartan; sildenafil and olmesartan; sildenafil and olmesartan medoxomil; sildenafil and telmisartan; 25 sildenafil and valsartan; tadalafil and candesartan; tadalafil and eprosartan; tadalafil and irbesartan; tadalafil and losartan; 30 tadalafil and olmesartan; tadalafil and olmesartan medoxomil; WO 2004/002461 PCT/IB2003/002657 11 tadalafil and telmisartan; tadalafil and valsartan; vardenafil and candesartan; vardenafil and eprosartan; 5 vardenafil and irbesartan; vardenafil and losartan; vardenafil and olmesartan; vardenafil and olmesartan medoxomil; vardenafil and telmisartan; and 10 vardenafil and valsartan. The pharmaceutical combinations of the invention are useful in the treatment of diseases including cardiovascular and metabolic diseases, and they may also be useful in the treatment of other diseases such as thrombosis, and in the 15 management of patients following percutaneous translumenal coronary angioplasty ("post-PTCA patients"). Preferably the cardiovascular disorder to be treated is hypertension, congestive heart failure, angina, stroke or renal failure. More preferably the cardiovascular 20 disorder is essential hypertension, pulmonary hypertension, secondary hypertension, isolated systolic hypertension, hypertension associated with diabetes, hypertension associated with atherosclerosis, renovascular hypertension, congestive heart failure, angina, stroke or renal failure. In a particularly preferred embodiment, the disorder to be treated is essential hypertension. In another 25 particularly preferred embodiment, the disorder to be treated is pulmonary hypertension. In another particularly preferred embodiment, the disorder to be treated is secondary hypertension. In another particularly preferred embodiment, the disorder to be treated is isolated systolic hypertension. In another particularly preferred embodiment, the disorder to be treated is hypertension associated with 30 diabetes. In another particularly preferred embodiment, the disorder to be treated is WO 2004/002461 PCT/IB2003/002657 12 hypertension associated with atherosclerosis. In another particularly preferred embodiment, the disorder to be treated is renovascular hypertension. Preferably the metabolic disease to be treated is impaired glucose tolerance or 5 diabetes, including complications thereof, such as diabetic retinopathy and diabetic neuropathy. More preferably the metabolic disease is impaired glucose tolerance, type-1 diabetes, non-insulin dependent type-2 diabetes or insulin-dependent type-2 diabetes. 10 The combination of the invention can be administered alone but will generally be administered in admixture with a suitable pharmaceutical excipient, diluent or carrier selected with regard to the intended route of administration and standard pharmaceutical practice. 15 For example, the combinations of the invention can be administered orally, buccally or sublingually in the form of tablets, capsules, multi-particulates, gels, films, ovules, elixirs, solutions or suspensions, which may contain flavouring or colouring agents, for immediate-, delayed-, modified-, sustained-, pulsed- or controlled-release applications. The combinations of the invention may also be administered as fast 20 dispersing or fast-dissolving dosage forms or in the form of a high energy dispersion or as coated particles. Suitable formulations may be in coated or uncoated form, as desired. Such solid pharmaceutical compositions, for example, tablets, may contain 25 excipients such as microcrystalline cellulose, lactose, sodium citrate, calcium carbonate, dibasic calcium phosphate, glycine and starch (preferably corn, potato or tapioca starch), disintegrants such as sodium starch glycollate, croscarmellose sodium and certain complex silicates, and granulation binders such as polyvinylpyrrolidone, hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose 30 (HPC), sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, stearic acid, glyceryl behenate and talc may be included.

WO 2004/002461 PCT/IB2003/002657 13 The following formulation examples are illustrative only and are not intended to limit the scope of the invention. Active ingredient means a combination of the invention. 5 Formulation 1: A tablet is prepared using the following ingredients: Active ingredient (50mg) is blended with cellulose (microcrystalline), silicon dioxide, stearic acid (fumed) and the mixture is compressed to form tablets. 10 Formulation 2: An intravenous formulation may be prepared by combining active ingredient (1 00mg) with isotonic saline (1000ml) The tablets are manufactured by a standard process, for example, direct 15 compression or a wet or dry granulation process. The tablet cores may be coated with appropriate overcoats. Solid compositions of a similar type may also be employed as fillers in gelatin or HPMC capsules. Preferred excipients in this regard include lactose, starch, a 20 cellulose, milk sugar or high molecular weight polyethylene glycols. For aqueous suspensions and/or elixirs, the PDE5 inhibitor and angiotensin il receptor antagonist 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. 25 Modified release and pulsatile release dosage forms may contain excipients such as those detailed for immediate release dosage forms together with additional excipients that act as release rate modifiers, these being coated on and/or included in the body of the device. Release rate modifiers include, but are not exclusively 30 limited to, hydroxypropylmethyl cellulose, methyl cellulose, sodium carboxymethylcellulose, ethyl cellulose, cellulose acetate, polyethylene oxide, WO 2004/002461 PCT/IB2003/002657 14 Xanthan gum, Carbomer, ammonio methacrylate copolymer, hydrogenated castor oil, carnauba wax, paraffin wax, cellulose acetate phthalate, hydroxypropylmethyl cellulose phthalate, methacrylic acid copolymer and mixtures thereof. Modified release and pulsatile release dosage forms may contain one or a combination of 5 release rate modifying excipients. Release rate modifying excipients may be present both within the dosage form i.e. within the matrix, and/or on the dosage form, i.e. upon the surface or coating. Fast dispersing or dissolving dosage formulations (FDDFs) may contain the 10 following ingredients: aspartame, acesulfame potassium, citric acid, croscarmellose sodium, crospovidone, diascorbic acid, ethyl acrylate, ethyl cellulose, gelatin, hydroxypropylmethyl cellulose, magnesium stearate, mannitol, methyl methacrylate, mint flavouring, polyethylene glycol, fumed silica, silicon dioxide, sodium starch glycolate, sodium stearyl fumarate, sorbitol, xylitol. The terms dispersing or 15 dissolving as used herein to describe FDDFs are dependent upon the solubility of the drug substance used i.e. where the drug substance is insoluble a fast dispersing dosage form can be prepared and where the drug substance is soluble a fast dissolving dosage form can be prepared. 20 The combinations of the invention can also be administered parenterally, for example, intracavernously, intravenously, intra-arterially, intraperitoneally, intrathecally, intraventricularly, intrau reth rally, intrasternally, intracranially, intramuscularly or subcutaneously, or they may be administered by infusion or needleless injection techniques. For such parenteral administration they are best 25 used in the form of a sterile aqueous solution which may contain other substances, for example, enough salts or glucose to make the solution isotonic with blood. The aqueous solutions should be suitably buffered (preferably to a pH of from 3 to 9), if necessary. The preparation of suitable parenteral formulations under sterile conditions is readily accomplished by standard pharmaceutical techniques well 30 known to those skilled in the art.

WO 2004/002461 PCT/IB2003/002657 15 The following dosage levels and other dosage levels herein are for the average human subject having a weight range of about 65 to 70kg. The skilled person will readily be able to determine the dosage levels required for a subject whose weight falls outside this range, such as children and the elderly. 5 The dosage of the combination of the invention in such formulations will depend on its potency, but can be expected to be in the range of from 1 to 500mg of PDE5 inhibitor and 1 to 300mg of angiotensin il receptor antagonist for administration up to three times a day. A preferred dose is in the range 10 to 100mg (e.g. 10, 25, 50 10 and 100mg) of PDE5 inhibitor and 20 to 150mg (e.g. 20, 50, 100 and 150mg) of angiotensin 11 receptor antagonist which can be administered once, twice or three times a day (preferably once). However the precise dose will be as determined by the prescribing physician and will depend on the age and weight of the subject and severity of the symptoms. 15 For oral and parenteral administration to human patients, the daily dosage level of a combination of the invention will usually be from to 5 to 500mg/kg (in single or divided doses). 20 Thus tablets or capsules may contain from 5mg to 250mg (for example 10 to 100mg) of the combination of the invention for administration singly or two or more at a time, as appropriate. The physician in any event will determine the actual dosage which will be most suitable for any individual patient and it will vary with the age, weight and response of the particular patient. The above dosages are 25 exemplary of the average case. There can, of course, be individual instances where higher or lower dosage ranges are merited and such are within the scope of this invention. The skilled person will appreciate that the combinations of the invention may be taken as a single dose as needed or desired (i.e. prn). It is to be appreciated that all references herein to treatment include acute treatment (taken as required) 30 and chronic treatment (longer term continuous treatment).

WO 2004/002461 PCT/IB2003/002657 16 The combinations of the invention can also be administered intranasally or by inhalation and are conveniently delivered in the form of a dry powder inhaler or an aerosol spray presentation from a pressurised container, pump, spray, atomiser or nebuliser, with or without the use of a suitable propellant, e.g. 5 dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, a hydrofluoroalkane such as 1,1,1,2-tetrafluoroethane (HFA 134A [trade mark]) or 1,1,1,2,3,3,3-heptafluoropropane (HFA 227EA [trade mark]), carbon dioxide or other suitable gas. In the case of a pressurised aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurised 10 container, pump, spray, atomiser or nebuliser may contain a solution or suspension of the active compound, e.g. using a mixture of ethanol and the propellant as the solvent, which may additionally contain a lubricant, e.g. sorbitan trioleate. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated to contain a powder mix of the combinations of the invention and 15 a suitable powder base such as lactose or starch. Aerosol or dry powder formulations are preferably arranged so that each metered dose or "puff" contains from 1 gg to 50mg of a combination of the invention for delivery to the patient. The overall daily dose with an aerosol will be in the range of 20 from 1pgg to 50mg which may be administered in a single dose or, more usually, in divided doses throughout the day. Alternatively, the combinations of the invention can be administered in the form of a suppository or pessary, or they may be applied topically in the form of a gel, 25 hydrogel, lotion, solution, cream, ointment or dusting powder. The combinations of the invention may also be dermally or transdermally administered, for example, by the use of a skin patch, depot or subcutaneous injection. They may also be administered by the pulmonary or rectal routes. 30 For application topically to the skin, the combinations of the invention can be formulated as a suitable ointment containing the active compound suspended or WO 2004/002461 PCT/IB2003/002657 17 dissolved in, for example, a mixture with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, they can be formulated as a suitable lotion or cream, suspended or dissolved in, for example, a 5 mixture of one or more of the following: mineral oil, sorbitan monostearate, a polyethylene glycol, liquid paraffin, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. The combinations of the invention may also be used in combination with a 10 cyclodextrin. Cyclodextrins are known to form inclusion and non-inclusion complexes with drug molecules. Formation of a drug-cyclodextrin complex may modify the solubility, dissolution rate, bioavailability and/or stability property of a drug molecule. Drug-cyclodextrin complexes are generally useful for most dosage forms and administration routes. As an alternative to direct complexation with the drug the 15 cyclodextrin may be used as an auxiliary additive, e.g. as a carrier, diluent or solubiliser. Alpha-, beta- and gamma-cyclodextrins are most commonly used and suitable examples are described in published international patent applications W091/11172, W094/02518 and W098/55148. 20 Oral administration of the combinations of the invention is a preferred route, being the most convenient. In circumstances where the recipient suffers from a swallowing disorder or from impairment of drug absorption after oral administration, the drug may be administered parenterally, sublingually or buccally. 25 The combinations of the invention may be used as part of a triple therapy regimen, i.e. a treatment protocol in which the patient is treated with three pharmaceutical agents. The third agent in the triple therapy may be a second PDE5 inhibitor or angiotensin il receptor antagonist, or it may be chosen from a third pharmacological group. For example, it may be a neutral endopeptidase inhibitor, an angiotensin 30 converting enzyme inhibitor, a calcium channel blocker such as amlodipine, a statin WO 2004/002461 PCT/IB2003/002657 18 such as atorvastatin, a beta blocker (i.e. a beta-adrenergic receptor antagonist) or a diuretic. It will be appreciated that the invention covers the following further aspects and that 5 the embodiments specified hereinabove for the first aspect extend to these aspects: i) a pharmaceutical combination of the invention (for simultaneous, separate or sequential administration) for treating hypertension; 10 ii) a kit for treating hypertension, the kit comprising: a) a first pharmaceutical composition comprising a PDE5 inhibitor; b) a second pharmaceutical composition comprising an angiotensin II receptor antagonist; and c) a container for the compositions; 15 iii) a method of treating hypertension in a subject comprising treating said patient with an effective amount of a combination of the invention. Assay Preferred compounds suitable for use in accordance with the present invention are 20 potent and selective PDE5 inhibitors. In vitro PDE inhibitory activities against cyclic guanosine 3',5'-monophosphate (cGMP) and cyclic adenosine 3',5'-monophosphate (cAMP) phosphodiesterases can be determined by measurement of their IC 0 values (the concentration of compound required for 50% inhibition of enzyme activity). 25 The required PDE enzymes can be isolated from a variety of sources, including human corpus cavernosum, human and rabbit platelets, human cardiac ventricle, human skeletal muscle and bovine retina, essentially by a modification of the method of Thompson, WJ et al.; Biochemistry 18(23), 5228-5237, 1979, as described by Ballard SA et al.; J. Urology 159(6), 2164-2171, 1998. In particular, 30 cGMP-specific PDE5 and cGMP-inhibited cAMP PDE3 can be obtained from human corpus cavernosum tissue, human platelets or rabbit platelets; cGMP-stimulated WO 2004/002461 PCT/IB2003/002657 19 PDE2 was obtained from human corpus cavernosum; calcium/calmodulin (Ca/CAM)-dependent PDE1 from human cardiac ventricle; cAMP-specific PDE4 from human skeletal muscle; and photoreceptor PDE6 from bovine retina. Phosphodiesterases 7-11 can be generated from full length human recombinant 5 clones transfected into SF9 cells. Assays can be performed either using a modification of the "batch" method of Thompson WJ and Appleman MM; Biochemistry 10(2),311-316, 1971, essentially as described by Ballard SA et al.; J. Urology 159(6), 2164-2171, 1998, or using a 10 scintillation proximity assay for the direct detection of [ 3 H]-labelled AMP/GMP using a modification of the protocol described by Amersham plc under product code TRKQ7090/71 00. In summary, for the scintillation proximity assay the effect of PDE inhibitors was investigated by assaying a fixed amount of enzyme in the presence of varying inhibitor concentrations and low substrate, (cGMP or cAMP in a 3:1 ratio 15 unlabelled to [ 3 H]-labeled at a concentration of ~1/3 Km or less) such that IC 5 0 = K. The final assay volume was made up to 1 00pl with assay buffer [20mM Tris-HCI pH 7.4, 5mM MgCl 2 , 1 mg/ml bovine serum albumin]. Reactions were initiated with enzyme, incubated for 30-60min at 30 0 C to give <30% substrate turnover and terminated with 50gi yttrium silicate SPA beads (containing 3mM of the respective 20 unlabelled cyclic nucleotide for PDEs 9 and 11). Plates were re-sealed and shaken for 20min, after which the beads were allowed to settle for 30min in the dark and then counted on a TopCount plate reader (Packard, Meriden, CT) Radioactivity units were converted to % activity of an uninhibited control (100%), plotted against inhibitor concentration and inhibitor IC50 values obtained using the 'Fit Curve' 25 Microsoft Excel extension. Animal study The efficacy of the combinations of the invention has been demonstrated in an 30 animal model of human hypertension using candesartan as a representative angiotensin receptor II antagonist and 3-ethyl-5-[5-(4-ethylpiperazin-1-ylsulphonyl)- WO 2004/002461 PCT/IB2003/002657 20 2-(2-methoxyethoxy)pyridin-3-yi]-2-(pyridin-2-yl)methyl-2,6-dihydro-7H-pyrazolo[4,3 d]pyrimidin-7-one (the compound of Example 4 of published international patent application W099/54333) as a representative PDE5 inhibitor. 5 Animals The spontaneously hypertensive rat (SHR) is a widely used model of human hypertension. Anaesthetised male SHRs (250-450g) were surgically prepared for the measurement of systolic, diastolic and mean arterial pressure. Cannulae were inserted into the jugular veins and carotid artery. The trachea was also cannulated 10 to facilitate respiration. Following a 60min post-surgical stabilisation period, arterial blood pressure and heart rate were recorded via a pressure transducer and PoNeMah data acquisition system. Drugs 15 Solutions of candesartan (0.02, gg/kg/min), PDE5 inhibitor (15.6pg/kg/min) and a combination of PDE5 inhibitor and candesartan (15.6pg/kg/min + 0.02, pg/kg/min) were infused as appropriate at a rate of 0.5mL/h. Control animals received compound vehicle (5% DMSO, 10% PEG200, 85% water for injection (v/v)). 20 Protocol Baseline haemodynamic parameters were recorded. Animals (n=6/group) were randomised to receive a primed infusion of either vehicle or PDE5 inhibitor for a period of 60min. At this point, these groups were further randomised to receive either (i) vehicle or PDE5 inhibitor alone, (ii) candesartan alone or (iii) a combination 25 of candesartan and PDE5 inhibitor. Changes in mean arterial pressure were monitored during the study period. Summary data, expressed as change in mean arterial pressure vs. vehicle treated animals are presented in the Table below.

WO 2004/002461 PCT/IB2003/002657 21 Treatment candesartan PDE5 Combination (0.02sg/kg/min) inhibitor Change in mean arterial pressure from vehicle -3.2 -7.4 -32.6 (mmHg) The data demonstrate that the combination effect of a fall in MAP of 32.6 mmHg is significantly larger that the sum of the two individual effects (7.4 mmHg for PDE5 inhibitor and 3.2 mmHg for candesartan) (p=0.058). 5

Claims

5-[2-ethoxy-5-(4-methyl-1 -piperazinylsulphonyl)phenyl]-1 -methyl-3-n-propyl 1,6-dihydro-7H-pyrazolo[4,3-dJpyrimidin-7-one (sildenafil); (6R,12aR)-2,3,6,7,12,12a-hexahydro-2-methyl-6-(3,4-methylenedioxyphenyl) pyrazino[2', 1':6,1]pyrido[3,4-b]indole-1,4-dione (tadalafil); 2-[2-ethoxy-5-(4-ethyl-piperazin-1 -yl-1 -sulphonyl)-phenyl]-5-methyl-7-propyl 3H-imidazo[5,1-fj[1,2,4]triazin-4-one (vardenafil); 3-(1 -methyl-7-oxo-3-propyl-6,7-dihydro-1 H-pyrazolo[4,3-dpyrimidin-5-yl)-N-(2 (1 -methylpyrrolidin-2-yl)ethyl)-4-propoxybenzenesulphonamide; WO 2004/002461 PCT/IB2003/002657 23 5-[2-ethoxy-5-(4-ethylpiperazin-1 -ylsulphonyl)pyridin-3-yl]-3-ethyl-2-[2 methoxyethyl]-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one; and 5-(5-acetyl-2-butoxy-3-pyridinyl)-3-ethyl-2-(1 -ethyl-3-azetidinyl)-2,6-dihydro 7H-pyrazolo[4,3-d]pyrimidin-7-one and pharmaceutically acceptable salts thereof. 5 The use according to claim 4, wherein the inhibitor of PDE5 is selected from 5-[2-ethoxy-5-(4-methyl-1 -piperazinylsulphonyl)phenyl]-1 -methyl-3-n-propyl 1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (sildenafil) and pharmaceutically acceptable salts thereof. 6 The use according to claim 5, wherein the inhibitor of PDE5 is sildenafil citrate. 7 The use according to any preceding claim, wherein the angiotensin I receptor antagonist is selected from candesartan, eprosartan, irbesartan, losartan, olmesartan, olmesartan medoxomil, saralasin, telmisartan and valsartan and pharmaceutically acceptable salts thereof. 8 The use according to claim 7, wherein the combination of the inhibitor of PDE5 and the angiotensin Il receptor antagonist is selected from sildenafil citrate and candesartan; sidenafil citrate and eprosartan; sildenafil citrate and irbesartan; sildenafil citrate and losartan; sildenafil citrate and olmesartan; sildenafil citrate and olmesartan medoxomil; sildenafil citrate and telmisartan; and sildenafil citrate and valsartan. WO 2004/002461 PCT/IB2003/002657 24 9 The use according to claim 1, wherein the medicament is for the treatment of hypertension 10 A pharmaceutical composition comprising an inhibitor of cyclic guanosine monophosphate specific phosphodiesterase type 5 (PDE5) and an angiotensin II receptor antagonist. 11 A pharmaceutical combination for simultaneous, separate or sequential administration for treating hypertension, comprising an inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) and an angiotensin 11 receptor antagonist. 12 A kit for treating hypertension, the kit comprising: a) a first pharmaceutical composition comprising a PDE5 inhibitor; b) a second pharmaceutical composition comprising an angiotensin II receptor antagonist; and c) a container for the compositions. 13 A method of treating hypertension in a subject comprising treating said patient simultaneously, separately or sequentially with an effective amount of an inhibitor of PDE5 and an angiotensin Il receptor antagonist.