(12) United States Patent
`Edmondson et al.
`
`111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US006699871B2
`US 6,699,871 B2
`(10) Patent No.:
`Mar.2,2004
`(45) Date of Patent:
`
`(54) BETA-AMINO HETEROCYCLIC
`DIPEPTIDYL PEPTIDASE INHIBITORS FOR
`THE TREATMENT OR PREVENTION OF
`DIABETES
`
`(75)
`
`Inventors: Scott D. Edmondson, New York, NJ
`(US); Michael H. Fisher, Ringoes, NJ
`(US); Dooseop Kim, Westfield, NJ
`(US); Malcolm Maccoss, Freehold, NJ
`(US); Emma R. Parmee, Scotch Plains,
`NJ (US); Ann E. Weber, Scotch Plains,
`NJ (US); Jinyou Xu, Scotch Plains, NJ
`(US)
`
`(73) Assignee: Merck & Co., Inc., Rahway, NJ (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 21 days.
`
`(21) Appl. No.: 10/189,603
`(22) Filed:
`Jul. 5, 2002
`Prior Publication Data
`(65)
`US 2003/0100563 A1 May 29, 2003
`
`Related U.S. Application Data
`Provisional application No. 60/303,474, filed on Jul. 6,
`2001.
`Int. Cl? .................. C07D 487/04; A61K 31!4985;
`A61P 3/04; A61P 3/10
`U.S. Cl. ........................................ 514/249; 544/350
`Field of Search ........................... 544/350; 514/249
`
`References Cited
`U.S. PATENT DOCUMENTS
`5,939,560 A
`8/1999 Jenkins et a!. .............. 548/535
`12/2000 Villhauer .................... 514/423
`6,166,063 A
`6,303,661 B1
`10/2001 Demuth eta!. ............. 514/866
`FOREIGN PATENT DOCUMENTS
`wo 97/40832
`11/1997
`
`(60)
`
`(51)
`
`(52)
`(58)
`
`(56)
`
`wo
`
`wo
`wo
`wo
`wo
`wo
`wo
`
`wo 98/19998
`wo 00/34241
`WO 01!34594 A1
`wo 01/96295 A3
`wo 01/96295 A2
`wo 02/02560 A2
`
`5/1998
`6/2000
`5/2001
`12/2001
`12/2001
`1!2002
`
`OTHER PUBLICATIONS
`
`"Novel N-substituted-2-cyanopyrrolidines as potent inhibi-
`tors of dipeptidyl peptidase IV in the treatment of non-in-
`sulin-dependent diabetes mellitus", Exp. Opin, Ther. Pat-
`ents, 10(12), pp. 1937-1942 (2000).
`Ashworth, et al., "2-Cyanopyrrolidides as Potent, Stable
`Inhibitors of Dipeptidyl Peptidase IV", Bioorg. Med. Chern.
`Lett., vol. 6, No. 10, pp. 1163-1166, (1996).
`Ashworth, et al., "4-Cyanothiazolidides as Very Potent,
`Stable Inhibitors of Dipeptidyl Peptidase IV", Bioorg. Med.
`Chern. Lett., vol. 6, No. 22, pp. 2745-2748, (1996).
`Deacon, et al., "Dipeptidyl peptidase IV inhibition as an
`approach to the treatment and prevention of type 2 diabetes:
`a historical perspective", Biochem. Biophys. Res. Commun.
`vol. 294, pp. 1-4 (2002).
`
`Primary Examiner-Mark L. Berch
`Assistant Examiner---Kahsay Habte
`(74) Attorney, Agent, or Firm---Philippe L. Durette; Melvin
`Winokur; 1. Eric Thies
`ABSTRACT
`(57)
`The present invention is directed to compounds which are
`inhibitors of the dipeptidyl peptidase-IV enzyme ("DP-IV
`inhibitors") and which are useful in the treatment or pre-
`vention of diseases in which the dipeptidyl peptidase-IV
`enzyme is involved, such as diabetes and particularly type 2
`diabetes. The invention is also directed to pharmaceutical
`compositions comprising these compounds and the use of
`these compounds and compositions in the prevention or
`treatment of such diseases in which the dipeptidyl peptidase-
`IV enzyme is involved.
`
`26 Claims, No Drawings
`
`DRL Ex. 1007, p. 001
`
`

`

`US 6,699,871 B2
`
`1
`BETA-AMINO HETEROCYCLIC
`DIPEPTIDYL PEPTIDASE INHIBITORS FOR
`THE TREATMENT OR PREVENTION OF
`DIABETES
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`This application claims priority under 35 U.S.C. §119(e)
`from Serial No. 60/303,474, filed Jul. 6, 2001.
`
`2
`correction of hyperglycemia. However, the two biguanides,
`phenformin and metformin, can induce lactic acidosis and
`nausea/diarrhea. Metformin has fewer side effects than
`phenformin and is often prescribed for the treatment of Type
`5 2 diabetes.
`The glitazones (i.e. 5-benzylthiazolidine-2,4-diones) are a
`more recently described class of compounds with potential
`for ameliorating many symptoms of type 2 diabetes. These
`agents substantially increase insulin sensitivity in muscle,
`10 liver and adipose tissue in several animal models of type 2
`diabetes resulting in partial or complete correction of the
`elevated plasma levels of glucose without occurrence of
`hypoglycemia. The glitazones that are currently marketed
`are agonists of the peroxisome proliferator activated recep-
`15 tor (PPAR), primarily the PPAR-gamma subtype. PPAR-
`gamma agonism is generally believed to be responsible for
`the improved insulin sensititization that is observed with the
`glitazones. Newer PPAR agonists that are being tested for
`treatment of Type II diabetes are agonists of the alpha,
`20 gamma or delta subtype, or a combination of these, and in
`many cases are chemically different from the glitazones (i.e.,
`they are not thiazolidinediones). Serious side effects (e.g.
`liver toxicity) have occurred with some of the glitazones,
`such as troglitazone.
`Additional methods of treating the disease are still under
`~
`investigation. New biochemical approaches that have been
`recently introduced or are still under development include
`treatment with alpha-glucosidase inhibitors (e.g. acarbose)
`and protein tyrosine phosphatase-1B (PTP-1B) inhibitors.
`Compounds that are inhibitors of the dipeptidyl
`peptidase-IV ("DP-IV" or "DPP-IV") enzyme are also under
`investigation as drugs that may be useful in the treatment of
`diabetes, and particularly type 2 diabetes. See for example
`WO 97/40832, WO 98/19998, U.S. Pat. No. 5,939,560,
`Bioorg. Med. Chern. Lett., 6(10), 1163-1166 (1996); and
`Bioorg. Med. Chern. Lett., 6(22), 2745-2748 (1996). The
`usefulness of DP-IV inhibitors in the treatment of type 2
`diabetes is based on the fact that DP-IV in vivo readily
`inactivates glucagon like peptide-1 ( GLP-1) and gastric
`inhibitory peptide (GIP). GLP-1 and GIP are incretins and
`are produced when food is consumed. The incretins stimu-
`late production of insulin. Inhibition of DP-IV leads to
`decreased inactivation of the incretins, and this in turn
`results in increased effectiveness of the in cretins in stimu-
`lating production of insulin by the pancreas. DP-IV inhibi-
`tion therefore results in an increased level of serum insulin.
`Advantageously, since the incretins are produced by the
`body only when food is consumed, DP-IV inhibition is not
`expected to increase the level of insulin at inappropriate
`times, such as between meals, which can lead to excessively
`low blood sugar (hypoglycemia). Inhibition of DP-IV is
`therefore expected to increase insulin without increasing the
`risk of hypoglycemia, which is a dangerous side effect
`associated with the use of insulin secretagogues.
`DP-IV inhibitors also have other therapeutic utilities, as
`discussed herein. DP-IV inhibitors have not been studied
`extensively to date, especially for utilities other than diabe-
`tes. New compounds are needed so that improved DP-IV
`inhibitors can be found for the treatment of diabetes and
`potentially other diseases and conditions.
`
`SUMMARY OF THE INVENTION
`The present invention is directed to compounds which are
`inhibitors of the dipeptidyl peptidase-IV enzyme ("DP-IV
`inhibitors") and which are useful in the treatment or pre-
`vention of diseases in which the dipeptidyl peptidase-IV
`
`BACKGROUND OF THE INVENTION
`Diabetes refers to a disease process derived from multiple
`causative factors and characterized by elevated levels of
`plasma glucose or hyperglycemia in the fasting state or after
`administration of glucose during an oral glucose tolerance
`test. Persistent or uncontrolled hyperglycemia is associated
`with increased and premature morbidity and mortality. Often
`abnormal glucose homeostasis is associated both directly
`and indirectly with alterations of the lipid, lipoprotein and
`apolipoprotein metabolism and other metabolic and hemo-
`dynamic disease. Therefore patients with Type 2 diabetes
`mellitus are at especially increased risk of macrovascular
`and microvascular complications, including coronary heart
`disease, stroke, peripheral vascular disease, hypertension,
`nep ropathy, neuropathy, and retinopathy. Therefore, thera-
`h
`peutical control of glucose homeostasis, lipid metabolism
`and hypertension are critically important in the clinical
`management and treatment of diabetes mellitus.
`There are two generally recognized forms of diabetes. In 30
`type 1 diabetes, or insulin-dependent diabetes mellitus
`(IDDM), patients produce little or no insulin, the hormone
`which regulates glucose utilization. In type 2 diabetes, or
`noninsulin dependent diabetes mellitus (NIDDM), patients
`often have plasma insulin levels that are the same or even 35
`elevated compared to nondiabetic subjects; however, these
`patients have developed a resistance to the insulin stimulat-
`ing effect on glucose and lipid metabolism in the main
`insulin-sensitive tissues, which are muscle, liver and adipose
`tissues, and the plasma insulin levels, while elevated, are 40
`insufficient to overcome the pronounced insulin resistance.
`Insulin resistance is not primarily due to a diminished
`number of insulin receptors but to a post-insulin receptor
`binding defect that is not yet understood. This resistance to
`insulin responsiveness results in insufficient insulin activa- 45
`tion of glucose uptake, oxidation and storage in muscle and
`inadequate insulin repression of lipolysis in adipose tissue
`and of glucose production and secretion in the liver.
`The available treatments for type 2 diabetes, which have
`not changed substantially in many years, have recognized 50
`limitations. While physical exercise and reductions in
`dietary intake of calories will dramatically improve the
`diabetic condition, compliance with this treatment is very
`poor because of well-entrenched sedentary lifestyles and
`excess food consumption, especially of foods containing 55
`high amounts of saturated fat. Increasing the plasma level of
`insulin by administration of sulfonylureas (e.g. tolbutamide
`and glipizide) or meglitinide, which stimulate the pancreatic
`~-cells to secrete more insulin, and/or by injection of insulin
`when sulfonylureas or meglitinide become ineffective, can 60
`result in insulin concentrations high enough to stimulate the
`very insulin-resistant tissues. However, dangerously low
`levels of plasma glucose can result from administration of
`insulin or insulin secretagogues (sulfonylureas or
`meglitinide ), and an increased level of insulin resistance due 65
`to the even higher plasma insulin levels can occur. The
`biguanides increase insulin sensitivity resulting in some
`
`DRL Ex. 1007, p. 002
`
`

`

`US 6,699,871 B2
`
`3
`enzyme is involved, such as diabetes and particularly type 2
`diabetes. The invention is also directed to pharmaceutical
`compositions comprising these compounds and the use of
`these compounds and compositions in the prevention or
`treatment of such diseases in which the dipeptidyl peptidase-
`IV enzyme is involved.
`
`DETAILED DESCRIPTION OF 1HE
`INVENTION
`
`The present invention is directed to compounds of the
`formula 1:
`
`4
`An embodiment of the present invention includes com-
`pounds of the formula Ia:
`
`!a
`
`wherein X, Ar and R 1 are defined herein;
`and pharmaceutically acceptable salts and individual dias-
`tereomers thereof.
`Another embodiment of the present invention includes
`compounds of the formula lb:
`
`Ib
`
`5
`
`10
`
`15
`
`20
`
`40
`
`30
`
`35
`
`wherein:
`Ar is phenyl which is unsubstituted or substituted with 25
`1-5 of R3
`, wherein R3 is independently selected from
`the group consisting of:
`(1) halogen,
`(2) C1_6alkyl, which is linear or branched and is unsub-
`stituted or substituted with 1-5 halogens,
`(3) oc1-6alkyl, which is linear or branched and is
`unsubstituted or substituted with 1-5 halogens, and
`(4) CN;
`X is selected from the group consisting of:
`(1) N, and
`(2) CR2
`;
`R1 and R2 are independently selected from the group
`consisting of:
`(1) hydrogen,
`(2) CN,
`(3) c1-10alkyl, which is linear or branched and which is
`unsubstituted or substituted with 1-5 halogens or
`phenyl, which is unsubstituted or substituted with
`1-5 substituents independently selected from 45
`halogen, CN, OH, R4
`, OR4
`, NHS02R4
`, S02R4
`,
`C02H, and C02C1_6alkyl, wherein the C02C1_6alkyl
`is linear or branched,
`(4) phenyl which is unsubstituted or substituted with
`1-5 substituents independently selected from 50
`halogen, CN, OH, R4
`, OR4
`, NHS02R4
`, S02R4
`,
`C02H, and C02C1_6alkyl, wherein the C02C1_6alkyl
`is linear or branched, and
`(6) a 5- or 6-membered heterocycle which may be
`saturated or unsaturated comprising 1-4 heteroatoms 55
`independently selected from N, S and 0, the hetero-
`cycle being unsubstituted or substituted with 1-3
`substituents independently selected from oxo, OH,
`halogen, c1-6alkyl, and oc1-6alkyl, wherein the
`c1-6alkyl and oc1-6alkyl are linear or branched and 60
`optionally substituted with 1-5 halogens;
`R4 is C1_6alkyl, which is linear or branched and which is
`unsubstituted or substituted with 1-5 groups indepen-
`dently selected from halogen, C02H, and C02C1_
`6alkyl, wherein the co2c1-6alkyl is linear or branched; 65
`and pharmaceutically acceptable salts thereof and indi-
`vidual diastereomers thereof.
`
`wherein Ar and R 1 are defined herein;
`and pharmaceutically acceptable salts and individual dias-
`tereomers thereof.
`Another embodiment of the present invention includes
`compounds of the formula Ic:
`
`Ic
`
`wherein Ar, R1 and R2 are defined herein;
`and pharmaceutically acceptable salts thereof and indi-
`vidual diastereomers thereof.
`In the present invention it is preferred that Ar is phenyl
`which is unsubstituted or substituted with 1-5 substitutents
`which are independently selected from the group consisting
`of:
`(1) fiuoro,
`(2) bromo, and
`(3) CF3 .
`In the present invention it is more preferred that Ar is
`selected from the group consisting of:
`(1) phenyl,
`(2) 2-fiuorophenyl,
`(3) 3,4-difiuorophenyl,
`( 4) 2,5-difiuorophenyl,
`(5) 2,4,5-trifiuorophenyl,
`( 6) 2-fiuoro-4-(trifiouromethyl)phenyl, and
`(7) 4-bromo-2,5-difiuorophenyl.
`In the present invention it is preferred that R 1 is selected
`from the group consisting of:
`(1) hydrogen, and
`(2) c1-6alkyl, which is linear or branched and which is
`unsubstituted or substituted with phenyl or 1-5 fiuoro.
`
`DRL Ex. 1007, p. 003
`
`

`

`5
`
`20
`
`US 6,699,871 B2
`
`5
`In the present invention it is more preferred that R 1 1s
`selected from the group consisting of:
`(1) hydrogen,
`(2) methyl,
`(3) ethyl,
`(4) CF3 ,
`(5) CH2CF3 ,
`(5) CF2 CF3
`(6) phenyl, and
`(7) benzyl.
`In the present invention it is more preferred that R 1 1s
`selected from the group consisting of:
`(1) hydrogen,
`(2) methyl,
`(3) ethyl,
`(4) CF3 , and
`(5) CH2CF3 .
`In the present invention it is even more preferred that R 1
`is hydrogen or CF3 .
`In the present invention it is preferred that R 2 is selected
`from:
`(1) hydrogen,
`(2) c1-6alkyl, which is linear or branched and which is
`unsubstituted or substituted with 1-5 fiuoro,
`(3) phenyl, which is unsubstituted or substituted with 1-3
`substituents independently selected from fiuoro, OCH3 ,
`and OCF3 .
`In the present invention it is more preferred that R 2 is
`selected from the group consisting of:
`(1) hydrogen,
`(2) methyl,
`(3) ethyl,
`(4) CF3 ,
`(5) CH2CF3 ,
`(5) CF2 CF3
`(6) phenyl,
`(7) ( 4-methoxy)phenyl,
`(8) ( 4-trifiuoromethoxy)phenyl,
`(9) 4-fiuorophenyl, and
`(10) 3,4-difiuorophenyl.
`In the present invention it is even more preferred that R 2
`is CF3 or CF2F3 .
`In the present invention it is preferred that R 3 is F, Br or
`CF3 .
`The compounds of the present invention may contain one 50
`or more asymmetric centers and can thus occur as race mates
`and racemic mixtures, single enantiomers, diastereomeric
`mixtures and individual diastereomers. The compounds of
`the instant invention have one asymmetric center at the beta
`carbon atom. Additional asymmetric centers may be present 55
`depending upon the nature of the various substituents on the
`molecule. Each such asymmetric center will independently
`produce two optical isomers and it is intended that all of the
`possible optical isomers and diastereomers in mixtures and
`as pure or partially purified compounds are included within 60
`the ambit of this invention. The present invention is meant
`to comprehend all such isomeric forms of these compounds.
`Some of the compounds described herein contain olefinic
`double bonds, and unless specified otherwise, are meant to
`include both E and Z geometric isomers.
`Some of the compounds described herein may exist as
`tautomers, which have different points of attachment of
`
`6
`hydrogen accompanied by one or more double bond shifts.
`For example, a ketone and its enol form are keto-enol
`tautomers. The individual tautomers as well as mixtures
`thereof are encompassed with compounds of the present
`invention.
`Formula I shows the structure of the class of compounds
`without preferred stereochemistry. Formula Ia shows the
`preferred sterochemistry at the carbon atom that is attached
`to the amine group of the beta amino acid from which these
`10 compounds are prepared.
`The independent syntheses of these diastereomers or their
`chromatographic separations may be achieved as known in
`the art by appropriate modification of the methodology
`disclosed herein. Their absolute stereochemistry may be
`15 determined by the x-ray crystallography of crystalline prod-
`ucts or crystalline intermediates which are derivatized, if
`necessary, with a reagent containing an asymmetric center of
`known absolute configuration.
`If desired, racemic mixtures of the compounds may be
`separated so that the individual enantiomers are isolated.
`The separation can be carried out by methods well known in
`the art, such as the coupling of a racemic mixture of
`compounds to an enantiomerically pure compound to form
`a diastereomeric mixture, followed by separation of the
`25 individual diastereomers by standard methods, such as frac-
`tional crystallization or chromatography. The coupling reac-
`tion is often the formation of salts using an enantiomerically
`pure acid or base. The diasteromeric derivatives may then be
`converted to the pure enantiomers by cleavage of the added
`30 chiral residue. The racemic mixture of the compounds can
`also be separated directly by chromatographic methods
`utilizing chiral stationary phases, which methods are well
`known in the art.
`Alternatively, any enantiomer of a compound may be
`35 obtained by stereoselective synthesis using optically pure
`starting materials or reagents of known configuration by
`methods well known in the art.
`The term "pharmaceutically acceptable salts" refers to
`salts prepared from pharmaceutically acceptable non-toxic
`40 bases or acids including inorganic or organic bases and
`inorganic or organic acids. Salts derived from inorganic
`bases include aluminum, ammonium, calcium, copper,
`ferric, ferrous, lithium, magnesium, manganic salts,
`manganous, potassium, sodium, zinc, and the like. Particu-
`45 larly preferred are the ammonium, calcium, magnesium,
`potassium, and sodium salts. Salts in the solid form may
`exist in more than one crystal structure, and may also be in
`the form of hydrates. Salts derived from pharmaceutically
`acceptable organic non-toxic bases include salts of primary,
`secondary, and tertiary amines, substituted amines including
`naturally occurring substituted amines, cyclic amines, and
`basic ion exchange resins, such as arginine, betaine, caffeine,
`choline, N,N'-dibenzylethylene-diamine, diethylamine,
`2-diethy laminae thanol, 2-dime thy laminae thanol,
`ethanolamine, ethylenediamine, N -ethyl-morpholine,
`N-ethylpiperidine, glucamine, glucosamine, histidine,
`hydrabamine, isopropylamine, lysine, methylglucamine,
`morpholine, piperazine, piperidine, polyamine resins,
`procaine, purines, theobromine, triethylamine,
`trimethylamine, tripropylamine, tromethamine, and the like.
`When the compound of the present invention is basic,
`salts may be prepared from pharmaceutically acceptable
`non-toxic acids, including inorganic and organic acids. Such
`acids include acetic, benzenesulfonic, benzoic,
`65 camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic,
`glutamic, hydrobromic, hydrochloric, isethionic, lactic,
`maleic, malic, mandelic, methanesulfonic, mucic, nitric,
`
`DRL Ex. 1007, p. 004
`
`

`

`US 6,699,871 B2
`
`7
`pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric,
`p-toluenesulfonic acid, and the like. Particularly preferred
`are citric, hydrobromic, hydrochloric, maleic, phosphoric,
`sulfuric, fumaric, and tartaric acids.
`It will be understood that, as used herein, references to the
`compounds of Formula I are meant to also include the
`pharmaceutically acceptable salts.
`As appreciated by those of skill in the art, halo or halogen
`as used herein are intended to include fluoro, chloro, bromo
`and iodo. Similarly, C1 _8 , as in C1 _8alkyl is defined to
`identify the group as having 1, 2, 3, 4, 5, 6, 7 or 8 carbons
`in a linear or branched arrangement, such that C1 _8alkyl
`specifically includes methyl, ethyl, n-propyl, iso-propyl,
`n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl.
`Likewise, C0 , as in C0alkyl is defined to identify the pres-
`ence of a direct covalent bond. A group which is designated
`as being independently substituted with substituents may be
`independently substituted with multiple numbers of such
`substituents. The term "heterocycle" as used herein is
`intended to include 5- or 6-membered ring systems which
`are within the following listing: benzimidazolyl,
`benzodioxanyl, benzofuranyl, benzopyrazolyl,
`benzothiadiazolyl, benzotriazolyl, benzothiophenyl,
`benzoxadiazolyl, benzoxazolyl, carbazolyl, carbolinyl,
`chromanyl, cinnolinyl, furanyl, imidazolyl, indolinyl,
`indolyl, indolazinyl, indazolyl, isobenzofuranyl, isoindolyl,
`isoquinolyl, isothiazolyl, isoxazolyl, naphthyridinyl,
`oxadiazolyl, oxazolyl, pyrazinyl, pyrazolyl, pyridopyridinyl,
`pyridazinyl, pyridyl, pyrimidyl, pyrrolyl, quinazolinyl,
`quinolinyl, quinoxalinyl, tetrazolyl, thiadiazolyl,
`thiazolidinyl, thiazolyl, thienyl, triazolyl, azetidinyl, 1,4-
`dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl,
`pyrrolidinyl, morpholinyl, thiomorpholinyl,
`dihydro b enzimid azo lyl, dihydro b enzofur anyl,
`dih ydro b enzo thiop he ny 1, dih ydro be nzo x azo 1 y 1,
`dihydrofuranyl, dihydroimidazolyl, dihydroindolyl,
`dih ydro iso ox azo 1 yl,
`dih ydro iso thi azo lyl,
`dihydrooxadiazolyl, dihydrooxazolyl, dihydropyrazinyl,
`dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl,
`dihydropyrrolyl, dihydroquinolinyl, dihydrotetrazolyl, 40
`dih ydro thiadiazo 1 y 1, dih ydro thiazo 1 y 1, dih ydrothien y 1,
`dih ydro tri azo lyl,
`dih ydro aze tid in yl,
`methylene dioxybe nzoyl,
`te tr ahydrofur an yl,
`tetrahydroimidazolyl, tetrahydroisoquinolinyl, and tetrahy-
`drothienyl.
`Exemplifying the invention is the use of the compounds
`disclosed in the Examples and herein.
`Specific compounds within the present invention include
`a compound which selected from the group consisting of the
`compounds disclosed in the following Examples and phar- 50
`maceutically acceptable salts thereof and individual diaste-
`reomers thereof.
`The subject compounds are useful in a method of inhib-
`iting the dipeptidyl peptidase-IV enzyme in a patient such as
`a mammal in need of such inhibition comprising the admin- 55
`istration of an effective amount of the compound. The
`present invention is directed to the use of the compounds
`disclosed herein as inhibitors of dipeptidyl peptidase-IV
`enzyme activity.
`In addition to primates, such as humans, a variety of other 60
`mammals can be treated according to the method of the
`present invention. For instance, mammals including, but not
`limited to, cows, sheep, goats, horses, dogs, cats, guinea
`pigs, rats or other bovine, ovine, equine, canine, feline,
`rodent or murine species can be treated. However, the 65
`method can also be practiced in other species, such as avian
`species (e.g., chickens).
`
`8
`The present invention is further directed to a method for
`the manufacture of a medicament for inhibiting dipeptidyl
`peptidase-IV enzyme activity in humans and animals com-
`prising combining a compound of the present invention with
`5 a pharmaceutical carrier or diluent.
`The subject treated in the present methods is generally a
`mammal, preferably a human being, male or female, in
`whom inhibition of dipeptidyl peptidase-IV enzyme activity
`is desired. The term "therapeutically effective amount"
`10 means the amount of the subject compound that will elicit
`the biological or medical response of a tissue, system,
`animal or human that is being sought by the researcher,
`veterinarian, medical doctor or other clinician.
`The term "composition" as used herein is intended to
`15 encompass a product comprising the specified ingredients in
`the specified amounts, as well as any product which results,
`directly or indirectly, from combination of the specified
`ingredients in the specified amounts. Such term in relation to
`pharmaceutical composition, is intended to encompass a
`20 product comprising the active ingredient(s), and the inert
`ingredient(s) that make up the carrier, as well as any product
`which results, directly or indirectly, from combination, com-
`plexation or aggregation of any two or more of the
`ingredients, or from dissociation of one or more of the
`25 ingredients, or from other types of reactions or interactions
`of one or more of the ingredients. Accordingly, the pharma-
`ceutical compositions of the present invention encompass
`any composition made by admixing a compound of the
`present invention and a pharmaceutically acceptable carrier.
`30 By "pharmaceutically acceptable" it is meant the carrier,
`diluent or excipient must be compatible with the other
`ingredients of the formulation and not deleterious to the
`recipient thereof.
`The terms "administration of" and or "administering a"
`35 compound should be understood to mean providing a com-
`pound of the invention or a prodrug of a compound of the
`invention to the individual in need of treatment.
`The utility of the compounds in accordance with the
`present invention as inhibitors of dipeptidyl peptidase-IV
`enzyme activity may be demonstrated by methodology
`known in the art. Inhibition constants are determined as
`follows. A continuous fluorometric assay is employed with
`the substrate Gly-Pro-AMC, which is cleaved by DP-IV to
`release the fluorescent AMC leaving group. The kinetic
`45 parameters that describe this reaction are as follows: 1(,=50
`1
`; kca/K,=1.5xl06 M- 1s- 1
`,uM; kcat=75 S-
`. A typical reac-
`tion contains approximately 50 pM enzyme, 50 ,uM Gly-
`Pro-AMC, and buffer (100 mM HEPES, pH 7.5, 0.1 mg/ml
`BSA) in a total reaction volume of 100 ,ul. Liberation of
`AMC is monitored continuously in a 96-well plate fluorom-
`eter using an excitation wavelength of 360 nm and an
`emission wavelength of 460 nm. Under these conditions,
`approximately 0.8 ,uM AMC is produced in 30 minutes at 25
`degrees C. The enzyme used in these studies was soluble
`(transmembrane domain and cytoplasmic extension
`excluded) human protein produced in a baculovirus expres-
`sion system (Bac-To-Bac, Gibco BRL). The kinetic con-
`stants for hydrolysis of Gly-Pro-AMC and GLP-1 were
`found to be in accord with literature values for the native
`enzyme. To measure the dissociation constants for
`compounds, solutions of inhibitor in DMSO were added to
`reactions containing enzyme and substrate (final DMSO
`concentration is 1% ). All experiments were conducted at
`room temperature using the standard reaction conditions
`described above. To determine the dissociation constants
`(K;), reaction rates were fit by non-linear regression to the
`Michaelis-Menton equation for competitive inhibition. The
`
`DRL Ex. 1007, p. 005
`
`

`

`US 6,699,871 B2
`
`9
`errors in reproducing the dissociation constants are typically
`less than two-fold.
`In particular, the compounds of the following examples
`had activity in inhibiting the dipeptidyl peptidase-IY
`enzyme in the aforementioned assays, generally with an
`I C50 of less than about 1 ,uM. Such a result is indicative of
`the intrinsic activity of the compounds in use as inhibitors
`the dipeptidyl peptidase-IY enzyme activity.
`Dipeptidyl peptidase-IY enzyme (DP-IY) is a cell surface
`protein that has been implicated in a wide range of biological
`functions. It has a broad tissue distribution (intestine, kidney,
`liver, pancreas, placenta, thymus, spleen, epithelial cells,
`vascular endothelium, lymphoid and myeloid cells, serum),
`and distinct tissue and cell-type expression levels. DP-IY is
`identical to the T cell activation marker CD26, and it can
`cleave a number of immunoregulatory, endocrine, and neu-
`rological peptides in vitro. This has suggested a potential
`role for this peptidase in a variety of disease processes in
`humans or other species.
`Accordingly, the subject compounds are useful in a
`method for the prevention or treatment of the following
`diseases, disorders and conditions.
`Type II Diabetes and Related Disorders: It is well estab-
`lished that the in cretins GLP-1 and GIP are rapidly inacti-
`vated in vivo by DP-IV. Studies with DP-IY(-i-)_deficient
`mice and preliminary clinical trials indicate that DP-IY
`inhibition increases the steady state concentrations of GLP-1
`and GIP, resulting in improved glucose tolerance. By anal-
`ogy to GLP-1 and GIP, it is likely that other glucagon family
`peptides involved in glucose regulation are also inactivated 30
`by DP-IY (eg. PACAP, glucagon). Inactivation of these
`peptides by DP-IY may also play a role in glucose homeo-
`stasis.
`The DP-IY inhibitors of the present invention therefore
`have utility in the treatment of type II diabetes and in the 35
`treatment and prevention of the numerous conditions that
`often accompany Type II diabetes, including metabolic
`syndrome X, reactive hypoglycemia, and diabetic dyslipi-
`demia. Obesity, discussed below, is another condition that is
`often found with Type II diabetes that may respond to 40
`treatment with the compounds of this invention.
`The following diseases, disorders and conditions are
`related to Type 2 diabetes, and therefore may be treated,
`controlled or in some cases prevented, by treatment with the
`compounds of this invention: (1) hyperglycemia, (2) low 45
`glucose tolerance, (3) insulin resistance, ( 4) obesity, (5) lipid
`disorders, ( 6) dyslipidemia, (7) hyperlipidemia, (8)
`hypertriglyceridemia, (9) hypercholesterolemia, (10) low
`HDL levels, (11) high LDL levels, (12) atherosclerosis and
`its sequelae, (13) vascular restenosis, (14) irritable bowel 50
`syndrome, (15) inflammatory bowel disease, including
`Crohn's disease and ulcerative colitis, (16) other inflamma-
`tory conditions, (17) pancreatitis, (18) abdominal obesity,
`(19) neurodegenerative disease, (20) retinopathy, (21)
`nephropathy, (22) neuropathy, (23) Syndrome X, (24) ova- 55
`rian hyperandrogenism (polycystic ovarian syndrome), and
`other disorders where insulin resistance is a component.
`Obesity: DP-IY inhibitors may be useful for the treatment of
`obesity. This is based on the observed inhibitory effects on
`food intake and gastric emptying of GLP-1 and GLP-2. 60
`Exogenous administration of GLP-1 in humans significantly
`decreases food intake and slows gastric emptying (Am. J.
`Physiol. 277, R910-R916 (1999)). ICY administration of
`GLP-1 in rats and mice also has profound effects on food
`intake (Nature Medicine 2, 1254--1258 (1996)). This inhi- 65
`bition of feeding is not observed in GLP-1R(-I-) mice,
`indicating that these effects are mediated through brain
`
`10
`GLP-1 receptors. By analogy to GLP-1, it is likely that
`GLP-2 is also regulated by DP-IV. ICY administration of
`GLP-2 also inhibits food intake, analogous to the effects
`observed with GLP-1 (Nature Medicine 6, 802-807 (2000)).
`5 Growth Hormone Deficiency: DP-IY inhibition may be
`useful for the treatment of growth hormone deficiency, based
`on the hypothesis that growth-hormone releasing factor
`(GRF), a peptide that stimulates release of growth hormone
`from the anterior pituitary, is cleaved by the DP-IY enzyme
`10 in vivo (WO 00/56297). The following data provide evi-
`dence that GRF is an endogenous substrate: (1) GRF is
`efficiently cleaved in vitro to generate the inactive product
`GRF[3-44] (BBA 1122, 147-153 (1992)); (2) GRF is rapidly
`degraded in plasma to GRF[3-44]; this is prevented by the
`15 DP-IY inhibitor diprotin A; and (3) GRF[3-44] is found in
`the plasma of a human GRF transgenic pig (J. Clin. Invest.
`83, 1533-1540 (1989)). Thus DP-IY inhibitors may be
`useful for the same spectrum of in