WO1999011271A1

WO1999011271A1 - Use of polycyclic steroid compounds for the manufacture of a medicament for the treatment of cystic kidney diseases, vascular infarction, uremia and related conditions

Info

Publication number: WO1999011271A1
Application number: PCT/CA1998/000825
Authority: WO
Inventors: Philip D. Acott; John F. S. Crocker
Original assignee: Dalhousie University
Priority date: 1997-08-29
Filing date: 1998-08-28
Publication date: 1999-03-11
Also published as: CA2302243A1; AU8968798A

Abstract

In accordance with the present invention, there are provided methods for the treatment of cystic renal diseases, vascular infarction, catabolic and growth consequences of uremia and other related indications in mammals, employing members of a defined class of polycyclic compounds as the active agent. In accordance with another embodiment of the present invention, it has been discovered that these compounds are effective agents for the treatment of renal dysplasias and/or renal hypoplasias in mammals. In accordance with yet another embodiment of the present invention, it has been discovered that these compounds are effective agents for enhancing glomerular development in mammals. In accordance with still another embodiment of the present invention, it has been discovered that these compounds are effective agents for enhancing kidney development in mammals suffering from chronic organ injury. In accordance with a further embodiment of the present invention, it has been discovered that these compounds are effective agents for protecting kidneys from the ongoing toxicity of treatment with steroid hormones. In accordance with a still further embodiment of the present invention, it has been discovered that these compounds are effective agents for maintaining substantially normal growth in neonates, pre-pubescent and pubertal mammals exposed to high dose steroid hormone therapy and improves the poor growth associated with the catabolic effects of chronic disease or uremia in these mammals. In accordance with yet a further embodiment of the present invention, it has been discovered that these compounds prevent or treat organ vascular infarction in mammals.

Description

USE OF POLYCYCLIC STEROID COMPOUNDS FOR THE MANUFACTURE OF A MEDICAMENT FOR THE TREATMENT OF CYSTIC KIDNEY DISEASES, VASCULAR INFARCTION, UREMIA AND RELATED CONDITIONS

FIELD OF THE INVENTION

The present invention relates to methods for the treatment of cystic kidney disease in mammals including 5 polycystic kidney disease, multicystic renal disease, renal cystic disease, and renal cysts. In another aspect, this invention relates to treatment of organ cysts in mammals. In another aspect, the present invention relates to methods for the treatment of renal dysplasias and/or

10 renal hypoplasias in mammals. In yet another aspect, the present invention relates to methods to enhance glomerular development in mammals. In still another aspect, the present invention relates to methods to enhance kidney development in mammals suffering from chronic organ

15 injury. In a further aspect, the present invention relates to methods to protect kidneys from the ongoing toxicity of treatment with steroid hormones . In a still further aspect, the present invention relates to methods to maintain substantially normal growth in neonates,

20 pre-pubescent and pubertal mammals exposed to high dose steroid hormone therapy. In a still further aspect, the present invention relates to methods for promoting improved growth in mammals who have a chronic disease, are subjected to glucocorticoid therapy, or suffer from renal

25 insufficiency or renal failure during infant life, childhood, and/or during puberty. In addition, the present invention relates to methods for the prevention and/or treatment of vascular infarction in an organ of a mammal . BACKGROUND OF THE INVENTION

Polycystic kidney disease is a heterogenous group of disorders characterized by large kidneys with epithelial lined cysts along the nephron collecting ducts of the affected kidneys. In all types of cystic kidney disease, the enlargement of the cyst wall is associated with hyperplasia of renal epithelium. There are several examples of genetic predisposition to cystic disease, with the most common forms of human polycystic kidney disease

(PKD) being genetically transmitted as either an autosomal dominant trait or an autosomal recessive trait . There are also several forms of acquired polycystic kidney disease.

Acquired lesions are caused by broad categories of agents, such as teratogens (e.g., diphenylamine and phthalates) , agents affecting metanephric development

(e.g., steroid hormones such as glucocorticoids) , and as a consequence of loss of renal mass (as seen in end-stage renal disease) . Even in kindreds with a defined genetic mutation, there is broad expression of the clinical phenotype. An example of this is a family with autosomal recessive PKD in several siblings, where the onset of renal failure was variable in the child and adolescent years. It is also well established that autosomal dominant PKD is asymptomatic in half of the kindred who are genetically affected, while approximately 1/6 go to renal failure. Moreover, the genetic trait does not discriminate the phenotypic variation of gender. The observation that the genetics are only one part of the clinical phenotype of PKD has created interest in looking at the pathophysiology of cystic disease and progression in the hope of finding modifying agents.

Currently, however, there is no effective treatment for Polycystic Kidney Disease (PKD) , one of the three leading causes of end stage renal failure in humans (Canadian Organ Replacement Register; p. 95 (1990)). Although PKD simulates Mendelian inheritance, there is evidence that phenotypic expression of PKD involves genetic heterogeneity and multifactorial inheritance, including nongenetic factors.

The ready availability of non-invasive imaging techniques of ultrasound, computerized axial tomography and nuclear magnetic resonance imaging has confirmed that PKD is a common human ailment (see, for example, Ogborn et al . , in Pediatr. Res. 2:123-146 (1988)). One in 1100 fetuses are affected and adult prevalence may be as high as l in 220. (Danovitch, in Cystic D seas s of the

Kidney. Gardner, KD (ed) , John Wiley & Sons Inc., Toronto, p. 125-150, (1975)); (Campbell, Clin. Pediatr. Urol .. Chapter 3: 181-186 (1951)). The probability of developing symptomatic renal insufficiency varies with age and pattern of presentation. It is known that both the number and size of cysts increase throughout life in this form of PKD, often starting in childhood. In the most common "adult" or dominantly inherited PKD (ADPKD) , end-stage renal failure has been described in patients ranging from infancy (Taitz et al . Arch . Pis. Child.. £2: 45-49 (1987)) to the ninth decade (Churchill et al . , Kid . Int . , 26 : 190-193 (1984)). In this situation the cysts appear in the kidney in such large numbers that the renal parenchyma is destroyed, thus contributing to end-stage renal failure.

The other major form of PKD is "infantile" or recessive PKD (ARPKD) , which also has a wide range of clinical presentation (Zerres, Pediatr. Nephrol . J_: 397-404 (1987)). ARPKD can first be detected during the second trimester of pregnancy. Unfortunately, therapeutic abortion is the only prenatal intervention currently available. The broad clinical spectrum of PKD suggests a complex interaction of genetic and other factors. Schimke has speculated that all forms of PKD may represent variable expression of common genes under different environmental influences (Schimke, Problems in Diagnosis and Management of Polycystic Kidney Disease. Grantham JJ and Gardner KD (eds.) PKR Foundation, Kansas City, 49-69, (1985) ) . This concept is supported by much of the available experimental evidence. Wirth et al . , (in Hum. Genet . 77: 221-222 (1987) ) , although not excluding such a concept, consider that family pedigrees and linkage studies confirm that ARPKD and ADPKD are mutations at distinct genetic loci, rather than being allelic mutations at the same locus .

Indeed, the locus of one gene marker of PKD, i.e., PKD1, has been mapped to chromosome 16 by Reeders et al . (Nature . 212:542-544 (1985)) and linked with biochemical polymorphisms and anonymous restriction fragment length polymorphism (RFLP) markers, thus permitting detection of asymptomatic individuals in the family (see also Reeders, Pediatr. Nephrol .. 1:405-410

(1987)). However, the gene(s) responsible for ADPKD in some families is/are not linked to the chromosome 16 locus (Kimberling et al . , HEJM, 319(14) .913-918 (1988)). This genetic heterogeneity suggests that genetic screening must be approached with caution (Germino et al . , Am . J. Hum . Gene . , 4£: 925-933 (1990)); Parfrey et al . , NEJM. 222:1085- 1090 (1990) ) .

In addition to the genetic heterogeneity of PKD, these traits show variable expressivity. The pathological features of the various forms of PKD exhibit overlaps, such as hepatic fibrosis, and distinguishing features, such as liver cysts in ADPKD. In addition, liver cystic disease may occur on its own without kidney cysts (Grunfeld et al . , Advances in Nephroloσy. 11:1-20 (1985)). There is currently an inability to diagnose this disease either early in its progression or even at all. This situation is supported by the greater incidence of PKD seen at autopsy rather than in clinical practice.

The ethical and practical difficulties of studying induction of renal cysts in humans have encouraged the study of animal models. These models are well characterized in recent reviews (see, for example, Ogborn et al . , Pediatr. Res.. supra ; Brenner, J . Am . Soc . Nephrol .. 1:127-139 (1990); Avner et al . , in: The Cystic Kidney. Eds. Gardner KD, Bernstein J, 55-98 (1990)). Reproducible models of PKD include those induced by organic chemicals- -specifically diphenylamine, diphenylthiazole and nordihydroguaiaretic acid and those induced by the administration of glucocorticoids (Avner et al . , supra) and (Perey et al . , Science. 158 : 494-496 (1967)) .

Accordingly, there is still a need in the art for effective methods for the diagnosis and treatment of each of the various forms of polycystic kidney disease, as well as related indications.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for the treatment of polycystic kidney disease and related indications in mammals.

In accordance with another embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for the treatment of renal dysplasias and/or renal hypoplasias in mammals. In accordance with yet another embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for augmenting glomerular development in mammals.

In accordance with still another embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for enhancing kidney development in mammals suffering from chronic organ injury.

In accordance with a further embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for protecting kidneys from the ongoing toxicity of treatment with steroid hormones .

In accordance with a still further embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for maintaining substantially more normal growth in neonatal, pre-pubescent, and pubertal mammals exposed to high dose steroid hormone therapy or with chronic renal disease .

In accordance with still a further embodiment of the present invention, we have discovered that members of a defined class of polycyclic compounds are effective agents for preventing and/or treating organ infarction in mammals.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 presents the daily weight profiles of neonatal C57B1/6J mice who were enrolled in the GIPKD model . Methylprednisolone acetate (MPA) treated mice were given 250 mg/kg/dose intramuscular on postnatal day 2 (P2) and greater than 95% developed cystic disease when assessed on P6. RU28362 (see Figure 9A for the structure of RU28362) was given subcutaneously from P2 to P6 (50 mg/kg/day) and observed to reduce growth in this strain but not to the degree seen with MPA. RU38486 (see Figure 9B for the structure of RU38486) was also given subcutaneously from P2 to P6 (50 mg/kg/day) , but did not influence growth negatively compared to control . In addition, RU38486 given to MPA treated animals (GIPKD) improved growth and reduced cystic disease. RU28362 at this dose aggravated growth of MPA treated animals. This most likely is a dose related phenomenon. Alternatively, RU28362 may be acting predominanantly as a glucocorticoid agonist over the short time period of this experiment prior to exerting its glucocorticoid antagonist role. Occasional subcortical cysts were seen in the RU28362 treated animals consistent with an initial partial glucocorticoid agonist role.

Figure 2 represents the data presented in Figure

1, corrected for the individual weight of each mouse at the onset of each treatment protocol on P2. The results presented herein show that MPA treated animals (i.e. MPA, RU28362 + MPA, and RU28362 + MPA) had the poorest net weight gain early in the experiment (i.e., from P2 to P3) .

In addition, the RU38486 + MPA treated mice have increased growth rates with catch-up growth later in this experiment. The additive effect of RU28362 to MPA appears to only occur in the last 2 days of the experiment .

Figure 3 presents the pooled litter serum creatinine levels for various treatment groups of C57BL/6J mice in the GIPKD model . Methylprednisolone acetate (MPA) treated animals (GIPKD) reveal evidence of renal insufficiency or failure which is totally protected by coadministration of RU38486. Control animals, as well as RU38486-treated animals, and RU28362-treated animals all had normal renal function. RU28362 did not improve serum renal function testing of MPA treated mice at the current dose and interval of this experiment .

Figure 4 presents the pooled litter serum urea for various treatment groups of C57BL/6J mice in the GIPKD model. MPA treated animals reveal evidence of renal insufficiency or failure which is totally protected by coadministration of RU38486. Control and RU38486 treated animals all had normal urea levels. RU28362 did not improve serum renal function testing of MPA treated mice at the current dose and interval of this experiment. In addition, RU28362-treated mice had mild elevation of urea levels. Elevated urea levels may reflect catabolism, renal insufficiency, dehydration and/or excessive protein intake and must be interpreted in conjunction with other parameters such as creatinine levels, other chemistry findings, weight gain, and clinical features.

Figure 5 presents plots of Kaplan-Meier survival estimates for cpk/cpk mice who received either:

1) sham saline injections 3 times per week (control), n= 5;

2) RU28362 100 mg/kg/dose 3 times per week for the first 25 postnatal days (P25) , n=20; or

3) RU28362 100 mg/kg/dose 3 times per week for the first 45 postnatal days (P45) , n=17.

Both the P25 and P45 treated mice lived significantly longer than control cpk/cpk mice, confirming that RU28362 enhances survival in this genetic model of polycystic kidney disease. Figure 6 presents the growth curves for the non-cystic littermates (normal mice) treated for 25 or 45 days with RU28362 100 mg/kg/dose 3 times per week. In both groups, the RU28362 treated normal mice had poorer growth than saline treated control mice.

Figure 7 presents the growth curves for the cpk/cpk mice enrolled in the experiment presented in Figures 5 & 6. At all time periods, the RU28362-treated mice showed improved growth compared to the control animals, despite the observation that RU28362 clearly impairs growth in the normal littermates, as demonstrated in Figure 6. This finding, in addition to the observation of improved survival (see Figure 5) supports the suggestion that RU28362 improves somatic growth in this model, despite the existence of cystic disease.

Figure 8 presents the pathological results in the cpk/cpk mice which were assessed at autopsy after death. The RU28362 treated mice were older and larger than their control counterparts, which may account for the similarity of percentage of functional renal cortical tissue, as these samples were obtained from animals who died naturally from their disease. RU28362-treated animals had more evidence of cell proliferation in their tubules (PCNA and Ki67 assessments) . Both groups had similar amounts of apoptosis (Frag-E ) in cells lining their cysts. The proportion of mice suffering acute terminal renal infarction was significantly reduced by RU28362 treatment (3 of 13) , compared to control cpk/cpk mice (11 of 12) .

Figure 9A presents the structure of RU28362.

Figure 9B presents the structure of RU38486. DETAILED DESCRIPTION QF THE; INVENTION

In accordance with the present invention, there are provided methods for the treatment of polycystic kidney disease in a mammal. Invention methods comprise administering to a mammal in need thereof an effective amount of a polycyclic compound having the structure I as follows :

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present , the unsaturation between C and C , C and C , and C and C is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

X is hydroxy or an aromatic moiety containing one or more heteroatom substituents thereon, and X¹⁷ is -CH₂CH₂CH₃, or

- (CH₂)_0#1-C°C-R, wherein R is H, CH₃, CF₃, CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph. As employed herein, "lower alkyl" refers to straight or branched chain alkyl radicals having in the range of about 1 up to about 4 carbon atoms .

As employed herein, "an aromatic moiety containing one or more heteroatom substituents thereon" refers to such substituted aromatics as 4- (N,N- dimethylamino)phenyl (i.e., 4- (N,N-NMe₂) Ph) , 4-(N-methyl, N-ethylamino)phenyl (i.e., 4-(N-Me, N-Et)Ph), biphenyl analogs thereof (i.e., 4- (N,N-NMe₂) Ph-Ph and 4- (N-Me, N-Et)Ph-Ph), as well as phenolic derivatives such as 4- (N,N-dimethylamino) -CH₂CH₂-0-phenyl or the thiophenol counterpart thereof, 4- (N,N-dimethylamino) -CH₂CH₂-S-phenyl, and the like. See also United States Patent No. 4,386,085, the entire contents of which are hereby incorporated by reference herein.

Exemplary compounds which fall within the above- described generic formula include RU28362 or RU38486. The structures of these presently preferred compounds are presented in Figure 9A and 9B, respectively.

As used herein, "mammal" signifies humans as well as other mammals, and includes animals of economic importance such as bovine, ovine, and porcine animals.

The preferred mammal contemplated for treatment according to the invention is a human. Adults as well as non-adults

(i.e., neo-nates, pre-pubescent mammals, pubertal mammals and the like) are contemplated for treatment in accordance with the invention.

As described above, polycystic kidney disease is a heterogenous group of disorders characterized by large kidneys with epithelial lined cysts along the nephron collecting ducts of the affected kidneys. PKD can be the result of genetic predisposition (genetically transmitted as either an autosomal dominant trait or an autosomal recessive trait, or as the result of a spontaneous genetic mutation) or polycystic kidney disease can be acquired as a result of exposure to a variety of environmental factors .

Acquired lesions are induced by exposure to broad categories of agents, such as, for example, teratogens (e.g., amines such as diphenylamine, plasticizers such as phthalates, as well as derivatives thereof), agents affecting metanephric development (e.g., steroid hormones such as glucocorticoids) , and as a consequence of loss of renal mass (as seen in end-stage renal disease) .

The defined class of polycyclic compounds contemplated for use herein includes compounds of structure I which are active in any species, including bovine, ovine, porcine, equine, and preferably human, in native-sequence or in variant form, and from any source, whether natural, synthetic, or recombinant. Also included within the scope of the present invention are analogs, homologs and mimics of the above-described compounds. Presently preferred herein for animal use are synthetic glucocorticoid ligands which have in vi tro and in vivo glucocorticoid ligand effects (agonists and antagonists) .

More preferably, these synthetic glucocorticoid ligands are produced and are available from Roussel-Uclaf ,

Romaineville, France, for laboratory and clinical investigations. See, for example, United States Patent No. 4,386,085, the entire contents of which are hereby incorporated by reference herein. Synthesis of the above- described compounds can be readily carried out employing techniques known to thos of skill in the art. See, for example, Teutsch et al . , in Steroids 22(6) : 651-665 (1981) and Teutsch et al . , in J. steroid Biochem. 21(4B) : 549-565 (1988) , both of which are hereby incorporated by reference herein in their entirety. As used herein, reference to "analogs, homologs and mimics" of polycyclic compounds of the invention (e.g., RU38486 and RU28362) embraces compounds which differ from the structure of these compounds by as little as the replacement and/or deletion of one or more residues thereof, to compounds which have no apparent structural similarity. Such compounds in all instances, however, have substantially the same activity as the polycyclic compounds described herein. Thus, "analogs" refers to compounds having the same basic structure as RU38486 or RU28362, but differing in several residues; "homologs" refers to compounds which differ from RU38486 or RU28362 by the deletion and/or replacement of a limited number of residues; and "mimics" refers to compounds which have no specific structural similarity with respect to RU38486 or RU28362 (indeed, a mimic need not even be a synthetic hormone or synthetic glucocorticoid ligand) , but such compound will display the biological activity characteristic of the polycyclic compounds described herein and/or stimulate endogenous glucocorticoid production or feedback loops in the body.

As used herein, "treatment" refers to therapeutic and prophylactic treatment. Those in need of treatment include those already with the disorder as well as those in which treatment of the disorder has failed.

Polycyclic compounds (e.g., RU38486 and RU28362) employed in invention treatment methods can be directly administered to the mammal by any suitable technique, including parenterally, intranasally, orally, transdermally, or by any other effective route. Examples of parenteral administration include subcutaneous, intramuscular, intravenous, intraarterial, and intraperitoneal administration. Most preferably, the administration is carried out employing a suspension in liposomes or by injection (using e.g., intravenous or subcutaneous means) . It is presently preferred that the administration of polycyclic compounds according to the invention be accomplished by suspension in liposomes and administered by subcutaneous injection. Alternatively, polycyclic compounds according to the invention may also be administered as a single bolus, by slow-release, by depot formulation, and the like.

It may be desirable to administer other renally active molecules that promote reabsorption and retention of electrolytes in conjunction with polycyclic compounds according to the invention. Examples of such renally active molecules include lipophilic hormones (e.g. Thyroxine, Tri-iodothyronine, retinoic acid, and the like), growth factors (e.g. Insulin-like growth factor type 1 and/or analogs including binding proteins, epidermal growth factor, transforming growth factor, and the like) , atrial natriuretic peptide (ANP) , ANP analogs, or any variants thereof with or without receptor activity, urodilatin, human B-type natriuretic peptide (BNP) , angiotension receptor antagonist, vasopressin and its analogs, endothelin antagonists (such as antibodies or peptide antagonists), and the like. One example is BQ-123 (Ihara et al . , Life Science, 50: 247-250 (1992); JP 51-94254A published August 3, 1993; Webb et al . , Biochem. Biophys. Res. Comm. , 185: 887-892 (1992)), a cyclic pentapeptide that is a potent and specific blocker of endothelin A receptors and blocks only the hypertrophic activity induced by endothelin-1, not CT-1, mouse LIF, or phenylephrine . Another example is the parent compound to BQ-123 described by Ihara et al . , Biochim. Biophys. Res. Comm., 178: 132-137 (1991). Further examples include those described in EP 647,236; EP 647,449; EP 633,259 (phenyl-sulfonyl amino-pyrimidine derivatives); EP 601,386 (sulfonamide compounds); U.S. Pat. No. 5,292,740 (phenylsulfonamidopyrimidines) ; and U.S. Pat. No. 5,270,313 (phenyl-sulfonyl-aminopyrimidine derivatives). In addition, angiotensin-converting enzyme (ACE) inhibitors may be beneficial in conjunction with the polycyclic compounds of the invention for the treatment of renal disorders .

The treatment regimen may be phasic with an alternating pattern of administration of one agent followed at a later time by the administration of the second agent. Phasic administration includes multiple administrations of one agent followed by multiple administrations of the second agent. The sequence that the agents are administered in and the lengths of each period of administration would be as deemed appropriate by the practitioner.

As a general proposition, the total pharmaceutically effective amount of polycyclic compounds according to the invention administered parenterally per dose will be an amount sufficient to provide a therapeutic effect without inducing a significant level of toxicity. Since individual subjects may present a wide variation in severity of symptoms and each form of polycyclic compounds according to the invention has its unique therapeutic characteristics, it is up to the practitioner to determine a subject's response to treatment and vary the dosages accordingly.

Typical dosages fall in the range of about 0.01 mg/kg/day up to about 100 mg/kg/day of patient body weight, although this is clearly subject to therapeutic discretion. Polycyclic compounds according to the invention are administered either by 1-2 injections per day or by continuous subcutaneous release, for example, using a liposome release system as in this invention, minipump, patch, implant, depot formulation, or the like. The preparations of RU38486 and RU28362 employed in the examples which illustrate this invention were dissolved in lipid microsomes at a concentration of 7.5 mg/ml under the direction of Dr. M. Mezei from the

Pharmacy Department at Dalhousie University and was administered subcutaneously. Dr. Mezei developed the encapsulation procedure which has been used in the past for these chemicals and other similar compounds (see, for example, United States Patent No. 4,485,054 (1984), inventors Mezei and Nugent) . A multiphase liposomal drug delivery system (United States Patent No. 4,761,288

(1988) , inventor M. Mezei) has been used for RU38486 and

RU28362 which is very appropriate for a controlled-drug release and subcutaneous administration.

Polycyclic compounds according to the invention may be suitably administered employing other sustained-release systems. Suitable examples of sustained-release compositions include semi-permeable polymer matrices in the form of shaped articles, e.g. films, or microcapsules . Sustained-release matrices include polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and gamma-ethyl -L-glutamate (Sidman et al . , PiQPQlymer , 22:547-556 (1983)), poly

(2-hydroxyethyl- methacrylate) (Langer et al . , J. Biomed.

Mater. Res.. 12:267-277 (1981)), ethylene vinyl acetate

(Langer et al . , supra) or poly-D-(-)-3 hydroxybutyric acid

(EP133,988), and the like.

Sustained-release compositions containing polycyclic compounds according to the invention also include liposomally entrapped polycyclic compounds. Liposomes are prepared by methods known in the art (see, for example, DE3,218,121; United States Patent Nos . 4,485,045 and 4,545,545). Ordinarily, liposomes are of small (about 200-800 Angstroms) unilamellar type, in which the lipid content is greater than about 30 mol . % cholesterol, the selected proportion being adjusted for the optimal therapeutic effect .

For parenteral administration, in one embodiment, polycyclic compounds according to the invention are formulated by mixing in a unit dosage injectable form (solution, suspension, or emulsion) , with a pharmaceutically acceptable carrier, i.e., one that is non-toxic to recipients at the dosages and concentrations employed and is compatible with other ingredients of the formulation. The formulation preferably does not include oxidizing agents and other compounds that are known to be deleterious to polycyclic compounds according to the invention.

Generally, the formulations are prepared by contacting polycyclic compounds according to the invention uniformly and intimately with liquid carriers or finely divided solid carriers or both. Then, if necessary, the product is shaped into the desired formulation. Preferably the carrier is a parenteral carrier, more preferably a solution that is isotonic with the blood of the recipient. Examples include water, saline, Ringers solution, dextrose solution, and the like. Non-aqueous vehicles such as fixed oils and ethyl oleate are also useful herein, as well as liposomes.

In addition, polycyclic compounds according to the invention are preferably suitably formulated in an acceptable carrier vehicle to form a pharmaceutical composition, preferably one that does not contain cells. In one embodiment, the buffer used for formulation will depend on whether the composition will be employed immediately upon mixing or stored for later use. Polycyclic compounds according to the invention to be used for therapeutic use must be sterile. Sterility is readily accomplished by filtration through sterile filtration membranes (e.g. 0.2 micron membranes). Therapeutic compositions containing polycyclic compounds according to the invention generally are placed into a container having a sterile access port, for example, a vial having a stopper pierceable by a hypodermic injection needle .

Polycyclic compounds according to the invention ordinarily will be stored in unit or multi-dose containers, for example, sealed ampoules or vials, as an aqueous solution, or as a lyophilized formulation for reconstitution.

In accordance with another embodiment of the present invention, there are provided methods for the treatment of renal dysplasias and/or renal hypoplasias in mammals, said method comprising administering an effective amount of a polycyclic compound according to the invention to said mammal .

Patients who present renal dysplasias and/or renal hypoplasias contemplated for treatment in accordance with the present invention are those having congenital renal anomalies.

In accordance with yet another embodiment of the present invention, there are provided methods to enhance glomerular development in mammals, said method comprising administering an effective amount of polycyclic compounds according to the invention to a mammal in need thereof.

Patients for whom enhanced glomerular development is indicated include patients with renal hypoplasia, renal dysplasia, spinal bifida, solitary kidneys, interuterine growth retardation, pediatric syndromes with growth anomalies (e.g., Turner's Syndrome and Down's Syndrome), and the like.

In accordance with still another embodiment of the present invention, there are provided methods to enhance kidney development in mammals suffering from chronic organ injury, said method comprising administering an effective amount of polycyclic compounds according to the invention to said mammal.

Patients for whom enhanced kidney development is indicated include adults who have undergone transplantation of a small kidney (wherein further growth of the organ is ablated) , subjects who suffer from renal tubule poisoning, subjects who have undergone chemotherapy (e.g., cancer patients), and the like.

In accordance with a further embodiment of the present invention, there are provided methods to protect kidneys from the ongoing toxicity of treatment with steroid hormones, said method comprising administering an effective amount of polycyclic compounds according to the invention to a mammal undergoing treatment with steroid hormones .

Patients for whom protection from the ongoing toxicity to kidneys of treatment with steroid hormones is indicated are patients suffering from any disease which is commonly treated by the administration of steroids, e.g., post renal transplant, nephrotic syndrome, primary and secondary glomerularnephritis, collagen vascular diseases, inflammatory bowel disease, rheumatoid arthritis, oncology patients and the like. In accordance with another embodiment of the present invention, there are provided methods to maintain substantially more normal growth in neonates, pre-pubescent mammals and pubertal mammals exposed to high dose steroid hormone therapy, said method comprising administering an effective amount of polycyclic compounds according to the invention to said mammal .

Another aspect of the present invention is improvement of growth and protection from the catabolic effects of chronic disease in mammals by administration of polycyclic compounds according to the invention thereto. The present invention, therefore, provides a method to improve growth and minimize growth at various ages in mammals with renal insufficiency/renal failure in association with renal cystic disease secondary to genetic predisposition or toxin/chemical induction, by administration of polycyclic compounds according to the invention.

Patients for whom maintenance of substantially normal growth is desired are neonates, pre-pubescent mammals, and pubertal mammals exposed to high dose steroid hormone therapy, which is used to treat a variety of indications, e.g., bronchopulmonary dysplasia in premature infants, nephrotic syndrome in children, collagen disorders, cancer patients, cystic fibrosis, asthma patients, rheumatoid arthritis, total villous atrophy, and the like. In addition, adults with acute or chronic medical conditions associated with catabolism would benefit from reduction of catabolism with these agents

(e.g. glucocorticoid ligands) . This includes adults with diseases treated with steroids who have glucocorticoid induced catabolism.

In accordance with another embodiment of the present invention, there are provided methods to prevent and/or treat vascular infarction in a mammalian organ. Patients whom may benefit from this aspect of the present invention include patients with myocardial angina or infarction, central nervous system ischemia (transient ischemic attacks) and or infarction (stroke) , retinopathy or retinal hemorrhage, aortic aneurysms, renal ischemic injury or infarction, vasculitis syndromes, peripheral vascular disease, and the like.

The invention will now be described in greater detail by reference to the following non-limiting examples .

EXAMPLES

The laboratory mouse as an experimental model is well characterized in PKD (Ogborn et al . , Pediatr. Res .. supra; Brenner, supra; Avner et al . , supra) . The murine model is universally utilized for a variety of reasons, e.g., because the genetics of inbred strains are well defined (Charlton, Quarterly J. Exp. Physiol .. 69 :655-676

(1984) ; In Handbook on Genetically Standardized Jax Mice.

3rd edition, Eds Heiniger and Dorey, The Jackson

Laboratory; and Genetic Variants and Strains of Laboratory Mouse , 2nd edition, Eds Lyon and Searle, Oxford University Press) . Moreover, patterns of mouse susceptibility to GC-induced PKD have been extensively examined. Furthermore, there are established Mendelian mutations resulting in PKD (Preminger et al . , J . Urol . , 127 : 556-560 (1982) ) , most notably the recessive cpk mutation, now localized to mouse chromosome 12 (Davisson et al . , Genomics . : 778-781 (1991)).

Histological and biochemical characterization of the k mutation has been extensively studied (see, for example, Crocker, et al . , in Kidney Int . 21:1088-1091 (1987); Cowley et al . , in Proc. Natl , Acad. Sci. USA. 24_.: 8394-8398 (1987); Ebihara et al . , in Lab. Invest. 22121:262-269 (1988) and Avner et al . in Kidney Int . 26_: 960-968 (1989)). The presence of hepatic cysts in heterozygous (cpk/+) animals have been described (Grimm et al., . Ex . Path .. 21: 119-131 (1990)). Indeed, there is strong evidence that both glucocorticoids and thyroid hormone are involved in the expression of the cpk/cpk mutation. This includes the increased levels of corticosteroids in mutants early in life and serum lipid and thyroid hormone profiles of mutants, consistent with hypothyroidism (Crocker et al . , Teratology. 43 :571-574

(1991) ) . It has also been observed that transgenic mice constitutively expressing the c-myc gene product (as a result of a SV40 promotor insert) are characterized by PKD (Trudel et al . , Kidney Int .. 22: 665- 671 (1991)), thus providing a valuable window on an early step in the pathophysiology of PKD.

Another model that may be used to study the progression of PKD is to administer large doses of glucocorticoids (GC) to newborn animals. This has been shown to induce PKD in rabbits (Baxter, Brit. J. Exp. Path.. X I: 140-149 (I960)), rats (Perey et al . , supra) , hamsters (Filmer et al . , Am. J. Path.. 72 (3) :461-468 (1973)), and mice (Crocker et al . , In Abnormal Functional Development of the Heart. Lungs and Kidneys. Eds. Kavlock and Grabowski, Liss, New York, p. 281-296 (1983)). As in the human disease, these cysts are lined by functioning tubular epithelium (Ojeda et al . , Nephron.. .12:240-248 (1986) ) . Hormonal manipulation, particularly with corticosteroids, increases glomerular filtration rates (Baylis et al . , Am. J. Physio! . 2_k2:F166-F170 (1978)), enlarges the area of tubular basolateral membranes (TBM) (Wade et al . , i Qe . EiΩl. 21:439-445 (1979)) and influences a wide range of transmembrane transport processes both on the luminal and basolateral surfaces of the tubular epithlium. Crocker et al . , supra, have established that acetate salts of GC were the most effective in inducing PKD and that such induction was independent of any hypokalemia that therapy might induce (Crocker et al . , Am. J. Path.. 82: 373-380 (1976)). It was then sought to explore the site of action of glucocorticoids by simultaneous treatment with agents opposing their electrolyte transport effects (Crocker et al . , Clin. Invest. Med.. Hill:16-21 (1988)). It was established that lithium chloride enhances cyst formation despite its natriuretic effects. Thus it is possible that both lithium and glucocorticoids may modulate a pathway of tubular proliferation that is independent of electrolyte transport.

During the course of the present studies, carried out in randomly inbred C57BL/6J mice, the possibility was considered that experiment-to-experiment differences might arise, in part, from divergence in various lines obtained from different suppliers. This hypothesis was tested by studying GC-induction potential in the mouse, using 18 well-characterized inbred strains.

All strains tested were found to be susceptible to PKD induction. The proportion of cystic change at a specific dose of methylprednisolone acetate (MPA, e.g., 250 mg/kg) and the spectrum of PKD severity was found to vary among strains in a manner best predicted by a multifactorial model with its continuous, normally distributed function of liability (i.e. susceptibility) (McDonald et al . , Kidney Int .. 22:901-908 (1990)). The C57B1/6J strain, the original background strain for the cpk mutation, has virtually the lowest threshold and, therefore, the highest proportion of affected animals. Other background strains, notably the DBA/2J have significantly less susceptibility, while the B10.M-H-2 congenic inbred strain was highly resistant . Glucocorticoids also produce cysts in murine embryonic organ culture (Avner et al . , Experientia. 40 : 489-490 (1984)), in the presence and absence of serum components. Avner et al . , supra, have shown that this phenomenon correlates with Na⁺K⁺ATPase activity, and can be reduced by treatment with ouabain (Avner et al . , Kidney Int., 2: 447-455 (1985)). Modification in the culture media of thyroid hormone levels, a potent inducer of the enzyme, also modified cyst production (Avner et al . , J. Lab. Clin. Med.. 109: 441-453 (1987)). There is evidence that the cellular distribution of the enzyme is abnormal in the organ culture model of PKD. Preliminary data suggest that C3H mice (a very susceptible strain) have a blunted response to induction of this ATPase by methylprednisolone acetate (MPA) compared to the relatively resistant DBA/2J strain, despite similar cytoplasmic receptor status (see, for example, Ogborn et al . , in Pediatr. Res. 22:335A (1990) and Ogborn et al . in Kidney Int . 22:425 (1990)). This is the reverse of what might be predicted from the in vitro work. As this enzyme is the source of the electrochemical gradient responsible for tubular transport of many solutes, induction of this enzyme would favour greater tubular transport of many solutes, induction of this enzyme would favour greater tubular egress of fluid and electrolytes in resistant animals, an effect that would oppose cyst growth. This can now be explained by change of location of Na+K+-ATPase in the tubular cell.

Work over the past two years has established the GIPKD model in C57BL/6J mice treated with methylprednisolone acetate (MPA) to be more lethal than the cpk/cpk model with >80% mortality by postnatal day 10 (P10) . This model has marked catabolism, poor weight gain and significant biochemical changes in 13 GIPKD litters compared with 15 control (c) litters by P6 : glucose = 26.3 (mean) ± 1.8 mmol/1 (standard error) (c= 41.2 ± 14.0); creatinine = 89.4 ± 13.9 mcmol/1 (c=10.5 ± 1.9); urea = 36.7 ± 2.3 mmol/1 (c=10.5 ± 1.9); potassium = 5.2 ± 0.6 mmol/1 (c=6.5 ± 0.5); phosphate = 4.5 ± 2.0 (c=3.6 + 1.9); uric acid = 37.4 ± 6.9 mmol/1 (c=26.1 ± 5.6); and albumin = 18.4 ± 0.7 g/1 (c=13.3 + 0.5).

The cpk mutation model for PKD was first described in detail by Preminger et al . , supra . Homozygous mutants (cpk/cpk) develop renal enlargement a few days after birth which are generally palpable at 10 to 14 days. Homozygous cpk mice have elevated plasma corticosterone levels early in postnatal life when adrenal corticosterone production is usually suppressed and unresponsive to physiologic stimuli (Crocker et al . , Kidney Int . , supra) . The homozygous mutants die within the first month of life. Recently, normal creatinine levels and elevated urea levels have been shown at pl5 and p20 in cpk/cpk mice (p20>pl5) . Near death, these mice have weight loss for 1 to 3 days, dehydration (5-10% weight decrease over 24 hr) , lethargy, and reduced intake. However, renal function tests in this period prior to death only reveal elevated creatinine in less than half of cpk/cpk mice despite marked elevations of urea uniformly.

Histologically, the cystic changes are characterized by early proximal tubular changes in late gestation (Nidess et al . , J . Urol .. 131 : 156-162 (1984)), and in organ explant are associated with increase sodium potassium AtPase activity (Avner et al . , Kidney Int . , supra) . These dilatations regress after birth as the severe terminal change of the distal nephron commences. These lesions bear strong resemblance pathologically to the glucocorticoid induced PKD which is seen in the C57B1/6J mouse. The evolution of PKD in cpk homozygotes is associated with increased expression of the c-myc proto-oncogene; however, the specificity of this response in the cpk model and its relation to cystogenic changes in cpk homozygote have not been addressed (Cowley et al . , supra) . In other tissues, this gene has been shown to be susceptible to glucocorticoid modulation (Forsthoefel et al . , Molec. Endocrin. 1H2L: 899-907 (1987)) which further implicates a central role to a glucocorticoid abnormality in PKD.

Cystic liver disease has been noted in 50% of cpk heterozygous mice by one year of age, making it pathologically similar to ADPKD, where 40% of patients show cystic liver disease. This makes the cpk mutant mouse model appear analogous to ADPKD rather than ARPKD, where hepatic fibrosis is seen uniformly (Grimm et al . , supra) . The homozygote cpk/cpk mice die by three to four weeks of age and thus one cannot tell whether cystic liver disease might develop in this subgroup.

Retinoic acid is a molecule belonging to the chemical class known as retinoids. In vivo, the retinoid exists as retinol, retinal, and all-trans-retinoic acid (RA) . Retinol and retinoic acid are essential in the control of epithelial growth and cellular differentiation and have important effects on embryonic development.

Embryonic developmental organogenesis is dependent upon growth, differentiation, pattern formation, and morphogenesis . Each of these processes is dependent upon inductive interactions between cells. Humes et al . , Exp. Cell Res.. 2111:8-15 (1992) worked with primary cultures of rabbit renal proximal tubule cells in hormonally defined, serum-free media treated with transforming growth factor-beta 1 (TGF-beta 1) , epidermal growth factor (EGF) , and all trans-retinoid acid singly or in combination. It was observed that all three factors were necessary and sufficient to transform lumens bordered by tubule cells possessing a polarized epithelial cell phenotype with extensive microvili-formation and tight junctional complexes along the lumenal border. RA promoted the deposition of the A and Bl chains of laminin, a cell attachment protein on the basement membrane in a small sub-set of proximal tubule cells and culture, as confirmed by indirect immunofluorescent microscopy. This confirmed a coordinated interplay between growth factors and retinoids to induce pattern formation and morphogenesis . Retinoic acid appeared to be essential for development of tubule epithelial cell polarity and lumen formation which is disrupted in PKD.

It is also noted that laminin production is changed at different periods of cyst development in PKD as reviewed by (Calvet, Kidney Int .. 42:101-108 (1993)). Humes et al . , supra, postulated the critical roles in tubulogenesis increased renal tubular cell adhesion and aggregation due to TGF-beta 1, stimulation of renal cell proliferation with EGF and induction of tubular cell polarization with RA. It is suggested that cells which respond to retinoic acid with laminin deposition are indeed the renal tubule stem cells capable of replication and terminal phenotypic differentiation.

Further effects of retinoids during vertebrate development are reviewed by Ragsdale et al . , Current Opinion in Cell Biol.. 3(6) : 928-934 (1991). Retinoids are required for vertebrate development and can act as teratogens partly due to their ability to cause cells to drop out of differentiation and division. They intervene in pattern formation at a strategic level as seen in their affect on polarization in chick limb-bud formation action.

At low doses, the main effect of retinoic acid is felt to be on patterning with complete block of growth and mitotic inhibition at high doses. There are alpha, beta and gamma forms of retinoic acid receptors in the human, mouse and rat genomes as reviewed by Mattei et al . , in Genomics_r 2:1061-1069 (1991) .

Growth factors are polypeptides which stimulate a wide variety of biological responses (e.g., DNA synthesis, cell division, expression of specific genes, etc.) in a defined population of target cells. A variety of growth factors have been identified, including the transforming growth factor family of polypeptides- -epidermal growth factor (EGF) , platelet-derived growth factor (PDGF) , fibroblast growth factor (FGF) , insulin-like growth factors (IGF-I and IGF-II) .

RU28362 is a synthetic glucocorticoid agonist which has high affinity for the Type II adrenal steroid receptor (Philibert D et al . in Endocrin Society 1018 : (abstract) , 1983). It promotes a strong catabolic effect which can be associated with reduced food intake and abolition of growth in rats (Langley SC et al . Biochem Pharmacology 3:543-551, 1993) .

Glucocorticoid action is mediated by 2 distinct receptor subtypes and is present in many peripheral tissues (Funder JW et al . Science 242:583-585, 1988). Type I sites (mineralocorticoid receptor) bind both mineralocorticoids and glucocorticoids and generally have weak affinity for synthetic steroids. In contrast, the Type II (glucocorticoid receptor) sites bind only glucocorticoids and have high affinity for synthetic steroids (Beaumont K et al . Endocrinology 113:2043-2051, 1984 and Reul JMHM, et al . Endocrinology 117:2505-2511, 1985) . Corticosterone in the rat and mouse has dual metabolic actions differentially mediated by specific binding to these sites (Devenport L et al . Life Sci 45:1389-1396, 1989). Type II binding classically promotes catabolic function while Type I binding promotes anabolic function. RU28362 is a specific, highly potent Type II agonist with little or no affinity for Type I sites (Philibert D et al . As above) . It is a potent antagonist of the same site with no apparent agonist activity (Moguilewsky M et al . J Steroid Biochem 20:271-276 , 1984) RU38486 is also an antagonist of the progesterone and androgen receptors (Baulieu E-E. Human Rep 3:541-547, 1988 and Spitz IM et al . N Engl J Med 329(6) :404-412, 1993) .

There is limited experience using RU28362 in vivo . Langley et al, dissolved RU28362 in 70% ethanol diluted in 0.9% saline and gave a dose of 30 mg/kg body weight intra peritoneal for 10 days in the genetically obese Zucker rat producing a strong catabolic effect with reduced food intake and abolition of growth (Langley SC et al. Biochem Pharmacology 3:543-551, 1993). In this experiment RU38486 also attenuated the growth of the rats and reduced their food intake. Reduced eating has been reported with other synthetic glucocorticoids in rat (Simpson GW et al . Pharm Biochem Behav 2:19-25, 1994) .

RU38486 blocks the Type II receptors, and in the hypothalamus this disrupts the hypothalamic-pituitary-adrenal access which leads to increasing circulating corticosterone concentrations. Corticosterone levels rise by 470% in the RU38486-treated obese Zucker rat (Langley SC et al . Am J Physiol 259:R539-R544, 1990). RU28362 would be expected to decrease corticosterone synthesis due to increased hypothalamic feedback. However, such a decrease was not shown in the genetic obese Zucker rat although this may be explained by the serum half life of 16 hours and the chemical being given at 24 -hour intervals. In these model systems, the RU28362 and RU38486 are supplied in liposomes with a more continuous exposure which would expect to increase the half life to more than 24 hours. This supports the interpretation that, in these models, RU28362 and RU38486 decrease endogenous corticosterone synthesis through the hypothalamic-pituitary-adrenal feedback loop.

The chemical structure of RU28362 is lib, 17b- dihydroxy-6-methyl-17 a- (propionyl) androsta-1, 4 , 6- triene-3-one . The 17 a-propionyl substitution is favorable for high local anti-inflammatory activity with reduced systemic activities in addition to compounds with this substitution being devoid of affinity for the aldosterone receptor and considered as pure glucocorticoid agonist (Teutsch G et al . Steroids 38 (6) : 651-665 (1981)).

RU38486 is the first potent glucocorticoid antagonist to have activity in vivo and was reported by the scientists from Roussel-UCLAF Company, Romaineville, France (Philibert D. et al . : RU38486: A potent antiαlucocorticoid in vivo. International Congress of

Pharmacology, Tokyo, Japan, 1463 (1981) ) . Its structure and biological function are reviewed including the antiglucocorticoid application by Spitz I. and Bardin C. (in NEJM, 329 (6) :404-412, 1993) and Chrousos G. et al (in Kidney Int., 34, Suppl . 26, 1988, pp. S18-S23)

Example 1

RU28362 Administration in cpk/cpk Mice

A total of 80 litters from known cpk heterozygote paired matings were enrolled in IGF treatment at 24 hours of age. This yielded a total of 82 proven cpk/cpk homozygotes confirmed by palpation of cystic kidneys in the second week of life and also by pathological assessment at death. The animals received either: Dsharn saline injections 3 times per week (control), n=45; 2) RU28362 100 mg/kg/dose 3 times per week subcutaneously for the the first 25 postnatal days

(P25) , n=20; or 3)RU28362 100 mg/kg/dose 3 times per week subcutaneously for the the first 45 postnatal days (P25) , n=17. The litters were separated between postnatal day 20 and 25 and all animals were killed on postnatal day 45.

All mice were weighed daily and animals who died prior to the closure of the study had weights recorded at death along with tissue taken with appropriate weights of the left kidney, right kidney and liver. The tissues were fixed in 10% formalin and processed for histological assessment. All animals completing 45 days in each treatment arm were sacrificed with recording of their weight, respective kidney weights, and liver weight. The kidneys and liver were put in 10% formalin for histological assessment. Blood was also taken from each animal .

Cpk/cpk homozygotes receiving RU28362 from P2 to P25 and from P2 to P45 both survived significantly longer than the saline-injected cpk/cpk control mice, as shown in Figure 5. The statistical assessment showed enhanced survival of cpk/cpk homozygotes receiving RU28362. There was no change in survival of the presumed heterozygote and normal litter mates, with the majority of the animals completing the 45 days of the study.

Kidney weights (volumes) were recorded at postmortem. Randomly selected left or right kidneys, after fixation, were systematically sampled and assessed by computer assisted, image analysis (Quantimet 570C) for the stereological measurement of cyst volume fraction, total cyst volume, fraction and volume of remaining functional tissue and intrarenal distribution. All results were related to postnatal day of death by regression analysis. 12/13 RU28362 treated cpk/cpk pups survived to and beyond 21 days (median 32, maximum 54), in contrast to 2/12 control animals (median 24, maximum 35 days). Anephric body weights (mean 5.3/5.76, medians 5.14/5.55 grams) were not significantly altered with RU28362. Renal weights were not significantly lower in exposed animals. Remaining functional renal cortical tissue, corrected either for survival time or anephric body weight was not significantly altered (RU28362 8.98, range 2-35%; controls 8.28, range 3-14%). In contrast 11/12 controls showed significant acute terminal renal ischaemic infarction (mean 27.2% of tissue, range 4-59%) whereas this was recorded in only 3/13 RU28362 animals

(mean infarct size 25%, range 5-54%) . In conclusion,

RU28362 significantly improves survival in cpk/cpk mice unrelated to changes in cortical cyst development and functional tissue sparing at postmortem. The pure glucocorticoid properties of this compound suggest a role for this receptor's action in the protective role of RU28362 with respect to terminal renal ischaemic infarction and the phenotypic expression of the cpk/cpk mouse .

It has, therefore, been demonstrated that the pure GC receptor ligand RU28362 can significantly prolong survival of the cpk/cpk model. Renal weights, anephric body weights, and remaining functional renal cortical tissue were not significantly altered even when corrected for survival time as shown in Figure 8. High apoptosis rates, high PCNA expression, and absence of Ki67 expression were seen in cysts in both groups. RU28362 exposed animals had elevated %PCNA and %Ki67 labelling in normal tubules compared to controls. In addition, 11/12 controls showed significant acute terminal renal infarction (mean=27.2% of tissue, range 4-59%) whereas this was recorded in only 3/13 RU28362 animals (mean infarct size=25%, range 5-54%) . The growth curves for the non-cystic littermates (normal mice) treated for 25 or 45 days with RU28362 100 mg/kg/dose 3 times per week are presented in Figure 6. The growth curves for the cpk/cpk mice enrolled in the 5 experiment are presented in Figures 7. In both groups the RU28362 treated normal mice had poorer growth than saline treated control mice. At all time periods the RU28362 treated cpk/cpk mice showed improved growth compared to the control animals despite the RU28362 clearly impairing 0 growth in the normal littermates as demonstrated in Figure 6. This finding in addition to improved survival of cpk/cpk (Figure 5) supports RU28362 improving somatic growth in this cpk/cpk model despite cystic disease.

5 Example 2

RU3B486 and RU28362 in Glucocor j oid-Induced PKD

The role of RU38486 and RU28362 in the GIPKD model was addressed. A total of 454 C57BL/6J newborn mice 0 were entered into the study at 24 hours of age after suckling was established with the mothers. They were divided into 6 groups :

A) control (n=71) ; 25 B) Methylprednisolone acetate (MPA) 250 mg/kg intramuscularly at 24 hours of age (n=62) ;

C) RU38486 50 mg/kg/dose subcutaneously daily P2 to P5 (n=82) ;

D) RU38486 and MPA (Methylprednisolone acetate 30 250 mg/kg intramuscularly at 24 hours of age and RU38486

50 mg/kg/dose subcutaneously daily P2 to P5) (n=44) ;

E) RU28362 50 mg/kg/dose subcutaneously daily P2 to P5 (n=82) ; and

F) RU28362 and MPA (Methylprednisolone acetate 35 250 mg/kg intramuscularly at 24 hours of age and RU28362

50 mg/kg/dose subcutaneously daily P2 to P5) (n=113) . Each litter had daily weights obtained of each mouse. All animals were killed at 120 hours of age (postnatal day 6) .

Glucose determination was done with glucometer Elite. Kidneys and livers were harvested and processed for 5 evaluation of the pathological scale of cystic disease. Blood was pooled from each litter for subsequent analysis.

RU38486 showed significant reduction of cyst severity of GIPKD with complete protection of some

10 animals. RU28362 showed only modest cyst reduction in the

GIPKD mice and on its own induced occasional subcapsular glomerular cysts .

In addition to pathological evidence of cyst

15 reduction, there was evidence of protection of renal function in the RU38486 treated GIPKD animals (creat =

35.9 ± 15.9, urea = 27.4 ± 2.6, n=12 litters) compared to

MPA treated alone GIPKD animals (creat = 89.4 ± 13.9, urea

= 36.7 ± 2.3, n=17 litters) . Renal function assays for

20 control C57BL/6J mice killed on postnatal day 6 (P6) were creat = 41.2 ± 14.4 and urea = 10.5 + 2.3 for 16 litters.

In this model there was deterioration of renal function with addition of RU28362 (MPA: creat = 89.4 ± 13.9, urea =

36.8 ± 2.3, n=17 litters; RU28362 + MPA: creat = 197 ±

25 25.7, urea = 53.16 ± 4.1, n=5 litters; RU28362: creat =

21.7 ± 23.5, urea = 20.0 ± 3.7, n=6 litters). The RU28362 treated animals were catabolic with poor growth in GIPKD model .

30 Alternatively, RU28362 may be acting mostly as a glucocorticoid agonist in the short time frame of the GIPKD model with a shift to a glucocorticoid antagonist effect with longer exposure such as the application in the cpk/cpk model. This is consistent with the variable

35 cellular responses seen with glucocorticoid ligands depending on their route of administration, cellular delivery, transport methods, relative potency, cell specificity, local concentration, receptor competition and other mechanisms which determine the ligand-cell response interaction.

The results presented herein confirm that:

1) Synthetic glucocorticoid ligands (i.e.

RU38486 and RU28362) can reduce the severity and incidence of glucocorticoid-induced renal cystic disease, 2) RU38486 and RU28362 have biological activity when given subcutaneously to neonatal animals with high doses tolerated in the first week of life,

3) RU38486 normalized the creatinine and urea levels seen in the GIPKD model, and 4) RU38486 protects the catabolic effects of high-dose corticorticoids on growth in neonatal mice.

The studies summarized in Examples 1 and 2 above document that RU38486 and RU28362 ameliorate renal cystic disease in mouse models. RU28362 reduced mortality in cpk/cpk model, and both RU38486 and RU28362 were seen to have a positive effect on somatic growth, RU28362 in the cpk/cpk model and RU38486 in the GIPKD model. In addition, RU28362 prevented or treated infarction of kidneys in the cpk/cpk model.

The enhancement of growth in mouse models of polycystic kidney disease by RU38486 and RU28362 support the conclusion that glucocorticoid ligands are useful therapeutic modalities in the treatment of neonatal, prepubescent , and pubertal growth failure induced by glucocorticoids and also in uremic induced or chronic disease induced growth failure.

In conclusion, it has been shown that a class of polycyclic compounds (e.g., RU38486 and RU28362) ameliorate renal cystic disease in both the genetic cpk/cpk mutant model and in GIPKD in C57BL/6J mice. These results provide insight into the pathway of cystic action within the kidney. It has also been shown that a class of polycyclic compounds (e.g., RU38486 and RU28362) can be administered to neonatal animals, with the benefit thereof in neonatal, pre-pubertal and pubertal growth being explicitly demonstrated even when chronic disease and/or renal cystic disease and/or renal failure/insufficiency is present .

While the invention has been described in detail with reference to certain preferred embodiments thereof, it will be understood that modifications and variations are within the spirit and scope of that which is described and claimed.

Claims

That which is claimed is

1. A method for the treatment of polycystic kidney disease in a mammal, said method comprising administering to a mammal in need thereof an effective amount of a polycyclic compound having the structure:

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present, the unsaturation between C¹ and C , C and C⁷, and C⁹ and C¹⁰ is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

X is hydroxy or an aromatic moiety containing one or more heteroatom substituents thereon, and

17

X is -CH₂CH₂CH₃ , or

- (CH₂ ) _{0 / 1}-C┬░ C-R, wherein R is H , CH₃ , CF₃ , CH₂CH₃, Si(CH₃)₃, Cl, phenyl , or CH₂CH₂-Ph.

2. A method according to claim 1 wherein said polycystic kidney disease is the result of genetic predisposition .

3. A method according to claim 2 wherein said polycystic kidney disease is transmitted as an autosomal dominant trait .

4. A method according to claim 2 wherein said polycystic kidney disease is transmitted as an autosomal recessive trait.

5. A method according to claim 1 wherein said polycystic kidney disease is the result of a spontaneous genetic mutation.

6. A method according to claim 1 wherein said polycystic kidney disease is acquired as a result of exposure to environmental factors .

7. A method according to claim 6 wherein said polycystic kidney disease is acquired in response to treatment with agents which affect metanephric development .

8. A method according to claim 7 wherein said agent which affects metanephric development is a steroid hormone .

9. A method according to claim 8 wherein said steroid hormone is a glucocorticoid.

10. A method according to claim 6 wherein said polycystic kidney disease is acquired in response to treatment with teratogenic agents .

11. A method according to claim 10 wherein said teratogenic agent is an amine or a plasticizer.

12. A method according to claim 11 wherein said amine is diphenylamine .

13. A method according to claim 11 wherein said plasticizer is a phthalate.

14. A method according to claim 1 wherein said mammal is human.

15. A method according to claim 1 wherein said mammal is a non-adult mammal.

16. A method according to claim 1 wherein said polycyclic compound having the structure I is RU38486 or RU28362.

17. A method according to claim 16 wherein said RU38486 or RU28362 acts as a glucocorticoid ligand.

18. A method according to claim 16 wherein said

RU38486 or RU28362 acts as a glucocorticoid ligand analog, homolog or mimic .

19. A method according to claim 16 wherein said RU38486 or RU28362 acts in vivo as a glucocorticoid ligand with agonist or antagonist action.

20. A method according to claim 1 wherein said polycyclic compound having the structure I is formulated in a pharmaceutically acceptable carrier.

21. A method according to claim 1 wherein said polycyclic compound having the structure I is formulated in sterile medium.

22. A method according to claim 1 wherein said polycyclic compound having the structure I is administered by continuous infusion, unit dosage, depot, or sustained release.

23. A method according to claim 1 wherein said polycyclic compound having the structure I is administered parenterally or any other means providing biological availability.

24. A method for the treatment of renal dysplasias and/or renal hypoplasias in a mammal, said method comprising administering an effective amount of a polycyclic compound having the structure I to a mammal in need thereof, wherein structure I is as follows:

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present , the

1 2 6 7 Q ╧ä_Q unsaturation between C and C , C and C , and C and C is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

- (CH₂) _0╬╣l-C┬░C-R, wherein R is H, CH₃, CF₃, CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph.

25. A method according to claim 24 wherein said mammal having a renal dysplasia or renal hypoplasia is a mammal having congenital renal anomalies.

26. A method to enhance glomerular development in a mammal, said method comprising administering an effective amount of a polycyclic compound having the structure I to a mammal in need thereof, wherein structure

I is as follows:

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present, the unsaturation between C 1 and C2 , C6 and C7 , and C9 and C10 is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

- (CH₂) _0/1-C┬░C-R, wherein R is H, CH₃, CF₃, CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph.

27. A method to enhance kidney development in a mammal suffering from chronic organ injury, said method comprising administering an effective amount of a polycyclic compound having the structure I to said mammal, wherein structure I is as follows:

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present, the unsaturation between C 1 and C2, C6 and C7, and C9 and C10 is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

X¹¹ is hydroxy or an aromatic moiety containing one or more heteroatom substituents thereon, and

X¹⁷ is -CH₂CH₂CH₃, or - (CH₂)_0#1-C┬░C-R, wherein R is H, CH₃, CF₃,

CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph.

28. A method to protect kidneys from the ongoing toxicity of treatment with steroid hormones, said method comprising administering an effective amount of a polycyclic compound having the structure I to a mammal undergoing treatment with steroid hormones, wherein structure I is as follows:

wherein: the A and B rings are optional, and can be replaced with appropriate groups which impart the requisite bulk and electronic features to said polycyclic compound so as to retain the desired agonist/antagonist effect, when the A and B rings are present, the

1 2 6 7 9 10 unsaturation between C and C , C and C , and C and C is optional, with the proviso that there is at least one site of unsaturation in the "B" ring of said polycyclic compound,

X is hydrogen, or lower alkyl,

- (CH₂)₀₍₁-C┬░C-R, wherein R is H, CH₃, CF₃, CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph.

29. A method to protect against, and/or treat vascular infarction in a mammalian organ, said method comprising contacting said organ with an effective amount of a polycyclic compound having the structure I, wherein structure I is as follows :

X is hydrogen, or lower alkyl,

30. A method according to claim 29 wherein said vascular infarction occurs in cardiac tissue, including cardiac angina or myocardial infarction.

31. A method according to claim 29 wherein said vascular infarction occurs in the central nervous system with transient ischemic attacks, vascular induced dementia or stroke .

32. A method according to claim 29 wherein said vascular infarction occurs in the kidney with acute tubular necrosis, post renal transplant renal rejection with vasculitis, nephritis secondary to vasculitis syndromes, glomerular fibrinoid necrosis, rapidly progressive glomerulonephritis (crescentic glomerulonephritis) , renal disease with colagen vascular diseases or renal infarction.

33. A method according to claim 29 wherein said vascular infarction occurs in peripheral tissue, and is peripheral vascular disease.

34. A method according to claim 33 wherein said peripheral vascular disease is diabetes, obesity, cigarette smoking, ischemic heart disease patients, deep vein thrombosis, burn or post trauma.

35. A method according to claim 29 wherein said vascular infarction occurs in the retina including retinopathy, proliferative retinopathy, diabetic retinopathy, hypertensive retinopathy, retinopathy of prematurity or retinal hemmorrhage .

36. A method according to claim 29 wherein said vascular infarction occurs in the skin including burn patients, trauma patients, birth defects, necrotizing vasculitis or plastic surgery procedures.

37. A method for the treatment of growth disturbances in mammals with renal cystic disease, chronic disease, or steroid induced catabolism, said method comprising administering an effective amount of a polycyclic compound having the structure I to said mammal, wherein structure I is as follows:

X is hydrogen, or lower alkyl,

- (CH₂)_0#1-C┬░C-R, wherein R is H, CH₃, CF₃, CH₂CH₃, Si(CH₃)₃, Cl, phenyl, or CH₂CH₂-Ph.