Patent Grant
7157498
The present invention relates to compounds having extracellular calcium ((Ca2+)e) and extracellular magnesium ((Mg2+)e) ion receptor or Calcium Sensing Receptor (CaSR) modulating activity. It relates in particular to a novel class of amine-containing compounds, their preparation, the pharmaceutical compositions containing them and their use as modulator of the activity of CaSRs and as medicament intended in particular for the treatment of physiological diseases or disorders involving the modulation of CaSR activity.
The CaSR modulating activity corresponds to the capacity to produce, induce or antagonize biological responses observed by the variations in the concentration of extracellular calcium ions (Ca2+)e and of extracellular magnesium ions (Mg2+)e. This activity may be of the calcimimetic type or of the calcilytic type.
The (Ca2+) e and (Mg2+)e ions play an important role in the body because they regulate calcium homeostasis on which depend the vital functions. Thus, hypercalcemia, that is to say states where the (Ca2+)e ions are above the mean threshold, have a major incidence on numerous functions such as cardiac, renal or intestinal functions. They deeply affect the central nervous system (Chattopadhyay et al., Endocr. Review, 1998, vol. 17, p. 289–307).
The CaSRs are proteins which are sensitive to (Ca2+)e and (Mg2+)e ions, and are present in the parathyroid glands, the kidney, the intestine, the lungs, the bone cells, the brain, the spinal cord, sensitive neurons the pituitary gland, the stomach, the keratinocytes (Brown et al., Nature, 1993, vol. 366, p. 575–580; Ruat et al., Proc. Natl. Acad. Sci., USA, 1995, vol. 92, p. 3161–3165; Brown et al., Ann. Rev. Med., 1998, vol. 49, p. 15–29). These proteins are encoded by a single gene isolated from various animal species. They belong to the family of G protein-coupled receptors with seven transmembrane domains, and exhibit structural homologies with the metabotropic glutamate receptors, GABAB receptors, hypothetical pheromone and taste receptors. Activating or inhibitory mutations of the gene in humans are responsible for extremely serious genetic diseases which cause hypocalcemia or hypercalcemia (Pollack et al., Cell, 1993, vol. 75, p. 1297–1303; Pollack et al., Nature Genetics, 1994, vol. 8, p. 303–307; Brown et al., Ann. Rev. Med., 1998, vol. 49, p. 15–29). The functions linked to the expression of these proteins in the tissues are not yet all known and are the subject of a very high research activity, particularly as regards the CaSRs present in the parathyroid and thyroid glands, the kidney, the intestine, the spinal cord, the brain and the bone cells.
In the parathyroid gland, the CaSRs modulate the secretion of the parathyroid hormone (PTH) which is the main regulator of calcium homeostasis: the increase in (Ca2+)e ions in the serum will activate the CaSRs present on the cells of the thyroid gland and reduce the secretion of the PTH hormone.
Complementary DNA encoding rat CaSR has been isolated from a rat striatum cDNA library (Ruat et al., Proc. Natl. Acad. Sci., 1995, vol. 92, p. 3161–3165). This receptor is identical with respect to its amino acid sequence to that expressed in the other tissues. Transfected Chinese hamster ovary_(CHO) cells expressing rat CaSR(CHO(CaSR)) have been characterized and the chemical signals (second messengers) induced by the activation of this receptor have been analyzed. Thus, a biochemical test which makes it possible to measure the accumulation of tritiated inositol phosphates [3H]IP in response to the activation of the receptor has been developed (Ruat et al., J. Biol. Chem., 1996, vol. 271, p. 5972–5975; Ferry et al., Biochem. Biophys. Res. Commun., 1997, vol. 238, p. 866–873).
It has been shown that the Ca2+, Mg2+, but also Ba2+ ions in millimolar concentration ranges stimulate the CaSRs. The activation of the CaSRs could be induced in the brain by the β-amyloid peptides which are involved in neurodegenerative diseases such as Alzheimer's disease (Ye et al., J. Neurosci. Res., 1997, vol. 47, p. 547–554).
Disruption of the CaSR activity is associated with biological disorders such as osteoporosis, Paget's disease, rheumatoid arthritis, tumors associated with humoral hypercalcemia, osteoarthritis, osteosarcomas, fractures, primary and secondary hyperparathyroidism, osteoporosis, cardiovascular, gastrointestinal, endrocrine or neurodegenerative diseases, or certain cancers in which (Ca2+)e ions are abnormally high.
Secondary hyperparathyroidism is observed during chronic renal insufficiency and is characterized by hyperplasia of the parathyroid glands and an increase in circulating PTH. Renal insufficiency is also accompanied by renal osteodystrophy which is characterized by bone disorders with a high or low renewal of the bone mass (osteitis fibrosa, osteomalacia).
Osteoporosis is a multifactorial disease which depends in particular on the age and the gender. While menopausal women are very highly affected, osteoporosis is found increasingly to be a problem in old men, and there are currently no truly satisfactory treatments. Its social cost could increase further in the coming years, particularly in our European society where the lifespan is increasing. Osteoporosis is currently treated with estrogens, calcitonin or biphosphonates which prevent bone resorption without stimulating new bone growth. More recent data demonstrate that intermittent increases in PTH or its derivatives are effective in the treatment of osteoporosis and make it possible to remodel the bone by stimulating bone formation (Whitfield et al., R. G. Landes Co., Austin, USA, 1998). This novel therapeutic route for the treatment of osteoporosis appears very advantageous although major problems are linked to the use of the PTH hormone such as the route of injection, but also the appearance of tumors which have been recently observed during clinical trials in humans. The intermittent secretion of endogenous PTH may be obtained by blocking the calcium receptor with the aid of an antagonist molecule, which is beneficial in the treatment of osteoporosis. The secretion of PTH may be blocked by CaSR agonists. This blocking may be followed by a rapid increase in PTH (rebound effect), which is also beneficial in the treatment of osteoporosis.
Taking into account the important role of calcium homeostasis, numerous CaSR modulators have already been used.
Thus, the company NPS Pharmaceutical has developed two main types of family of organic compounds as CaSR agonists, namely polyamines such as NPS 019 (3), and the arylalkylamines, small size molecules of which the best known representative to date is NPS R-568 (2). The compound NPS R-568 was developed from the structure of Fendiline (1), a potent activator of CaSR of the parathyroid gland.
The compound NPS-R-568 reduces or eliminates osteitis fibrosa in rats (Wada et al., Kidney International, 1998, vol. 53, p. 448–453) and reduces the PTH concentrations in patients (men) suffering from chronic renal insufficiency (Antansen et al., Kidney International, 1998, vol. 53, p. 223–227). This compound was successfully used orally to reduce the concentrations of PTH and of free serum Ca2+ ions in menopausal women suffering from primary hyperparathyroidism (Silverberg et al., New Engl. J. Med., 1997, vol. 337, p. 1506–1510). In another study, the compound NPS-R-568 made it possible to reduce between 20–50% the cell proliferation observed in the parathyroid gland in a rat model reproducing chronic renal insufficiency (Wada et al., J. Clin. Invest., 1997, vol. 100, p. 2977–2983). These studies demonstrate that a calcimimetic compound, which is active toward the calcium receptor present on the parathyroid gland, may be considered as an advantageous therapeutic tool for treating certain forms of primary and secondary hyperparathyroidism.
During clinical trials (Phase I–II), the company NPS Pharmaceutical observed a low bioavailability of the compound NPS-R-568 as well as variable clinical effects according to the individuals which could result from polymorphism of the gene encoding CaSR in humans (Nemeth et al., Trends Endoc. Metab, 1999, vol. 10, p. 66–71). Furthermore, during experimental trials in rats, the NPS R-467 compound, (an analog of NPS R-568 (2) in which the chlorine is replaced with a hydrogen) (Nemeth et al., PNAS (USA), 1998, vol. 95, p. 4040–4045) a compound having a structure similar to NPS R-568, proved more selective toward the receptors for the parathyroid compared to those for the thyroid gland. This selectivity can be explained by differences linked to the tissues, which suggests that calcimimetic molecules specific for a tissue may be synthesized and may have considerable clinical importance.
In parallel, the inventors recently reported the preparation and the calcimimetic activity of arylalkyl-1,2-diamines having the general structure described below (4), and among which the compound PHD 321 (5) constitutes one of the most active products.
The inventors also recently reported the synthesis of compounds of the following general formula (6):
in which:
As regards the CaSR antagonists, the companies SMITHKLINE BEECHAM and NPS Pharmaceutical have reported in recent patents the preparation of the compounds having the general structure 7 (WO9737967; WO9845255; WO9951241; WO9951569) and of compounds of the pyridinium type (WO9844925). Among these, the most active as calcilytic agents have an IC50 of less than 10−7 M. Such products open new therapeutic windows for the treatment of osteoporosis. However, their arylopropanolamine structure, close to those of β-adrenergics induces an undesirable residual activity at this level.
The complete absence of CaSR modulating molecules in clinical medicine and the problems encountered in phase I–II for first-generation calcimimetics underline the need to find novel molecules which modulate CaSR activity.
Consequently, the inventors set themselves the aim of preparing compounds which modulate CaSR activity and which do not possess the abovementioned disadvantages.
The present invention therefore relates to diamines of the following general formula (I):
in which:
Advantageously, A represents the group A1, B represents the group B2 and
represents the group CH(R25)—CH(R26) where R25 and R26 each represent a hydrogen atom.
Still more advantageously, X represents the SO2 group.
Particular examples of diamines according to the present invention are those chosen from the group consisting of the diamines of formulae (Ia) to (Id):
and their salts with a pharmaceutically acceptable acid.
The term “pharmaceutically acceptable acid” is understood to mean, for the purposes of the present invention; any nontoxic acid, including organic and inorganic acids. Such acids include acetic, benzenesulfonic, benzoic, citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric and para-toluenesulfonic acids. Hydrochloric acid is particularly preferred.
The term “alkyl group” is understood to mean, for the purposes of the present invention, any substituted or unsubstituted, linear or branched C1–C6 alkyl group, in particular the methyl group.
The term “cycloalkyl group” is understood to mean, for the purposes of the present invention, any substituted or unsubstituted, linear or branched C3–C6 cycloalkyl group.
The term “alkoxy group” is understood to mean, for the purposes of the present invention, any alkoxy group of 1 to 6 carbon atoms, which are linear or branched, substituted or unsubstituted, in particular the —OMe group.
The term “aryl group” is understood to mean, for the purposes of the present invention, one or more aromatic rings having 5 to 8 carbon atoms, which may be joined or fused, it being possible for said rings to be substituted. In particular, the aryl groups may be phenyl or naphthyl groups.
The term “aralkyl group” is understood to mean, for the purposes of the present invention, any aryl group as defined above, linked via an alkyl group as defined above. In particular, an aralkyl group is a benzyl or naphthylmethyl group.
The term “aryloxy group” is understood to mean, for the purposes of the present invention, any aryl group as defined above, linked to an oxygen atom.
The term “alkylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with a single alkyl group as defined above.
The term “dialkylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with two alkyl groups, which are identical or different, as defined above.
The term “cycloalkylamino” is understood to mean, for the purposes of the present invention any amine group in which the two substituents are linked to each other to form a C2–C6 cyclic aliphatic chain.
The term “arylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with a single aryl group as defined above.
The term “arylalkylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with a single arylalkyl group as defined above.
The term “diarylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with two aryl groups, which are identical or different, as defined above.
The term “diarylalkylamino” is understood to mean, for the purposes of the present invention, any amine group substituted with two aralkyl groups, which are identical or different, as defined above.
The term “trihaloalkyl” is understood to mean, for the purposes of the present invention, any alkyl group as defined above, substituted with three halogen atoms.
The term “trihaloalkoxy” is understood to mean, for the purposes of the present invention, any alkoxy group as defined above, substituted with three halogen atoms.
Preferred examples of a halogen atom are Cl and F.
The compounds according to the invention all have an asymmetric carbon and can therefore exist in the form of optical isomers. The present invention comprises these isomers pure or as a mixture.
The present invention also relates to the method of preparing these compounds.
The preparation of the molecules may be simply carried out in 4 or 5 stages depending on
of the general formula I. In all cases, the first two stages are the following:
in which:
to give the aziridine of general formula IV:
in which
in which B is as defined in formula I,
to give the diamine of general formula III
in which:
These two stages are carried out by methods well known to persons skilled in the art. The following stages depend on the type of radical X desired.
To obtain the diamines of general formula I in which X represents the CH2, C═O or COO group, respectively, and
represents the group CH2—CH2 or the group CH(R27)═CH(R28), method a)b) comprises, in addition, the following stages:
Stages c1) and d1) are carried out by methods well known to persons skilled in the art.
To obtain the diamines of general formula I in which X represents respectively the SO2 group and
represents the group CH2—CH2 or the group CH(R27)═CH(R28), method a)b) comprises, in addition, the following stages:
Stages c2) and d2) are carried out by methods well known to persons skilled in the art.
To obtain the diamines of general formula I in which
represents the group CH(R25)—CH(R26) where at least one of the radicals R25 and R26 does not represent the hydrogen atom, the method comprises, in addition, either after stage d1), or after stage d2), depending on the radical X desired, a final stage consisting in the selective introduction of the R25 and R26 radical(s) which do not represent the hydrogen atom into the molecule of the following general formula II:
in which:
The introduction of the R25 and/or R26 radical(s) may be carried out by methods well known to persons skilled in the art depending on the type of radical desired, in particular by epoxidation, aziridination, dihydroxylation, aminohydroxylation or Heck reaction.
The olefins of general formula VI and the compound of general formula V are easily commercially available. The compound of formula VII may be easily produced according to the method described by Evans et al. in Journal of the American Society, 1994, vol. 116, p. 2742.
The simplicity of the method of preparation of the compounds of formula I as described above and its very good yield make it possible to introduce a large variety of substituents R1 to R28.
The present invention also relates to pharmaceutical compositions comprising, as active ingredient, at least one of the diamines according to the present invention and an appropriate excipient. Such compositions may also comprise other active ingredients. These compositions may be formulated for administration to mammals, including humans. The dosage varies according to the treatment and according to the condition in question. These compositions are prepared so as to be administrable by the digestive or parenteral route.
In the pharmaceutical compositions of the present invention for oral, sublingual, subcutaneous, intramuscular, intravenous, transdermal, local or rectal administration, the active ingredient may be administered in unit forms for administration, mixed with conventional pharmaceutical carriers, to animals or to human beings. The appropriate unit forms for administration comprise the forms for administration by the oral route such as tablets, gelatin capsules, powders, granules and oral solutions or suspensions, the forms for sublingual and buccal administration, the forms for subcutaneous, intramuscular, intravenous, intranasal or intraocular administration and the forms for rectal administration.
When a solid composition is prepared in the form of tablets, the main active ingredient is mixed with a pharmaceutical vehicle such as gelatin, starch, lactose, magnesium stearate, talc, gum arabic and the like. It is possible to coat the tablets with sucrose or other appropriate materials or it is possible to treat them such that they have a prolonged or delayed activity and they continuously release a predetermined quantity of active ingredient.
A preparation in gelatin capsules is obtained by mixing the active ingredient with a diluent and by pouring the mixture obtained into soft or hard gelatin capsules.
A preparation in syrup or elixir form may contain the active ingredient together with a sweetener, an antiseptic, as well as a taste enhancer and an appropriate coloring agent.
The water-dispersible powders or granules may contain the active ingredient mixed with dispersing agents or wetting agents, or suspending agents, and with flavor correctors or sweeteners.
For rectal administration, suppositories are used which are prepared with binders which melt at rectal temperature, for example cocoa butter or polyethylene glycols.
For parenteral, intranasal or intraocular administration, aqueous suspensions, isotonic saline solutions or sterile and injectable solutions which contain pharmacologically acceptable dispersing agents and/or wetting agents are used.
The active ingredient may also be formulated in the form of microcapsules, optionally with one or more carrier additives.
The present invention also relates to the use of these diamines and of the pharmaceutical compositions containing them as modulator of CaSR activity.
Advantageously, the diamines according to the invention, for which X represents the SO2, C═O or COO group, may be used as CaSR antagonists and those for which the group X represents the CH2 group as CaSR agonists.
CaSRs can in particular be found in the parathyroid gland, the thyroid, the bone cells, sensitive neurones, the stomach, the lungs, the kidney, the pituitary gland, the brain, the hypothalamus, the olfactory surfaces or the hippocampus.
The diamines according to the invention and the pharmaceutical compositions comprising them can be used as a medicament, in particular for the treatment of physiological diseases or disorders linked to disturbances in the CaSR activity.
Still more particularly, in the case of the diamines for which X represents the SO2, C═O or COO group, these physiological diseases or disorders are of the type including demyelinating diseases associated with the expression of CaSRs in the oligodendrocytes, osteoporosis, Paget's disease, rheumatoid arthritis, tumors associated with humoral hypercalcemia, osteoarthritis, osteosarcomas, fractures, cardiovascular, gastrointestinal, endrocrin or neurodegenerative diseases or cancers where (Ca2+)e ions are abnormally high and in the case of the diamines for which X represents the CH2 group, these physiological diseases or disorders are of the type including diseases linked to hypercalcemia, primary or secondary hyperparathyroidism, osteoporosis, cardiovascular, gastrointestinal, endocrin or neurodegenerative diseases or certain cancers where the (Ca2+) e ions are abnormally high. Secondary hyperparathyroidism is more particularly observed during chronic renal insufficiency.
The present invention also relates to the aziridines of general formula IV:
in which:
The following example of synthesis of a compound according to the invention is given without limitation and illustrates the invention.
To a solution of copper trifluoromethanesulfonate (56 mg; 0.01 mmol) in 4 ml of acetonitrile distilled over CaCH2, in the presence of an activated molecular sieve, are successively added, at 0° C. under argon, cyclohexene (0.51 ml; 5 mmol) and, in portions over a period of 3 hours, [N-(p-methoxyphenylsulfonyl)imino]-phenyliodinane (Ph1═NSO2Ph-p-MeO) (0.390 g; 1 mmol). The heterogeneous mixture, which is green in color, is stirred at 0° C. for 6 hours before being filtered on silica (eluent: ethyl acetate) in order to remove the molecular sieve and the copper salts. After evaporation of the solvents, the yellow oily residue is purified by chromatography on silica (eluent: heptane/ethyl acetate: 4/1) to give 0.120 g (0.45 mmol; 45%) of an impure white solid.
Mass spectroscopy (Es)═m/z═267 [M+H]+
To a solution of aziridine prepared beforehand (80 mg; 0.30 mmol) in 1 ml of tetrahydrofuran (THF), are successively added triethylamine (0.009 ml; 0.06 mmol) and 1-(1-naphthyl)ethylamine (0.145 ml; 0.90 mmol). After stirring for 3 days at 60° C., the medium is concentrated before being purified on a silica column (eluent: heptane/ethyl acetate: 1/1). 125 mg (0.285 mmol; 95%) of the compound of aziridine opening are isolated in the form of a colorless foam. The diamine is then converted to its hydrochloride by treatment with a solution of HCl in methanol.
Mass spectrometry (ES): m/z: 439 [M+H]+
Melting point: 135–140° C. (decomposition)
The other compounds of Table 1 are prepared in the same manner as PHD 263.
1. Procedure
The calcilytic or calcimimetic activity of compounds according to the invention was estimated by measuring the inhibition of the accumulation of tritiated inositol phosphates induced by 9 mM extracellular calcium ions in the presence of 10 μM of each of the compounds in CHO(CaS) cells. The technique for measuring the accumulation of tritiated inositol phosphates [3H]IP which is used is that described in Ruat et al., J. Biol. Chem., 1996, vol. 271, p. 5972-5975. Only the mode of incubating the compounds is modified. After a preincubation of 15 min of the compounds according to the invention in the presence of a basal concentration of (Ca2+)e equal to 2 mM, the compounds are incubated for 30 min in the presence of a (Ca2+)e concentration of 4 or 9 mM. The results, mean of 2 to 4 independent experiments each carried out in triplicate, are grouped together in Table 2.
2. Result
The activity of the compounds is expressed as a percentage of the control activity measured in the presence of (Ca2+)e alone of concentration 4 mM or 9 mM.
The compound PHD 350 leads to a 25% inhibition of the accumulation of [3H]IP induced by 9 mM (Ca2+) et PHD 401 leads to an 82% inhibition under the same conditions and the compound PHD 263, for its part, inhibits the same response by 64%.
By contrast, the compounds PHD 346 and PHD 348 exhibit a calcimimetic activity since they activate the production of [3H]IP.
To assess the specificity of the antagonist activity of the molecules according to the invention, the effect of one of them, PHD 263, was studied under various calcium conditions, in the presence or otherwise of ATP on CHO(WT*) and CHO(CaSR) cells. The CHO(WT*) cells were transfected with the plasmid alone and do not express CaSR. The accumulation of tritiated inositol phosphates is expressed as a percentage of the basal level observed in the presence of 2 mM Ca2+ (100) in the CHO(WT*) or CHO(CaSR) cells.
The molecules according to the invention, used alone at a concentration of 10 μM, such as PHD 263, lead to little or no accumulation of [3H]IP in the control CHO(WT*) cells or the CHO(CaSR) cells (124±10%) which suggests a weak nonspecific activity in these cells independent of the presence of CaSR.
PHD 263 (10 μM) has the same effect on the [3H]IP response in the CHO(WT*) cells in the presence of 2 or 4 mM calcium, indicating an absence of a nonspecific effect of the compound linked to the variation of [Ca2+]e. The PHD 263 (10 μM) effect adds to that of ATP in these CHO(WT) cells; it does not therefore inhibit the [3H]IP response induced by another receptor coupled to the phospholipase C pathway.
| Number | Date | Country | Kind |
|---|---|---|---|
| 00 10427 | Aug 2000 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR01/02562 | 8/7/2001 | WO | 00 | 1/16/2004 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO02/12181 | 2/14/2002 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3262977 | Harsanyi et al. | Jul 1966 | A |
| Number | Date | Country |
|---|---|---|
| WO 9304373 | Mar 1993 | WO |
| WO 9304373 | Mar 1993 | WO |
| WO 9511221 | Apr 1995 | WO |
| WO 9511221 | Apr 1995 | WO |
| WO 9737967 | Oct 1997 | WO |
| WO 9844925 | Oct 1998 | WO |
| WO 9845255 | Oct 1998 | WO |
| WO 9951241 | Oct 1999 | WO |
| WO 9951569 | Oct 1999 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20050192317 A1 | Sep 2005 | US |
