BACKGROUND OF THE INVENTION
I. Field of the Invention
[0001] The present invention relates generally to the fields of biology and medicine. More
particularly, it concerns a compound for use in methods for improving renal (kidney)
function and/or for treating renal/kidney disease (RKD).
II. Description of Related Art
[0002] Renal failure, resulting in inadequate clearance of metabolic waste products from
the blood and abnormal concentrations of electrolytes in the blood, is a significant
medical problem throughout the world, especially in developed countries. Diabetes
and hypertension are among the most important causes of chronic renal failure, also
known as chronic kidney disease (CKD), but it is also associated with other conditions
such as lupus or systemic cardiovascular disease. Dysfunction of the vascular endothelium
commonly occurs in such conditions and is believed to be a major contributing factor
in the development of chronic kidney disease. Acute renal failure may arise from exposure
to certain drugs (
e.g., acetaminophen) or toxic chemicals or from ischemia-reperfusion injury associated
with shock or surgical procedures such as transplantation, and may ultimately result
in CKD. In many patients, CKD advances to end-stage renal disease (ESRD) in which
the patient requires kidney transplantation or regular dialysis to continue living.
Both of these procedures are highly invasive and associated with significant side
effects and quality of life issues. Although there are effective treatments for some
complications of renal failure, such as hyperparathyroidism and hyperphosphatemia,
no available treatment has been shown to halt or reverse the underlying progression
of renal failure. Thus, agents that can improve compromised renal function would represent
a significant advance in the treatment of renal failure.
[0003] Triterpenoids, biosynthesized in plants by the cyclization of squalene, are used
for medicinal purposes in many Asian countries; and some, like ursolic and oleanolic
acids, are known to be anti-inflammatory and anti-carcinogenic (Huang
et al., 1994; Nishino
et al., 1988). However, the biological activity of these naturally-occurring molecules is
relatively weak, and therefore the synthesis of new analogs to enhance their potency
was undertaken (Honda
et al., 1997; Honda
et al., 1998). An ongoing effort for the improvement of anti-inflammatory and antiproliferative
activity of oleanolic and ursolic acid analogs led to the discovery of 2-cyano-3,12-dioxooleane-1,9(11)-dien-28-oic
acid (CDDO) and related compounds (Honda
et al., 1997, 1998, 1999, 2000a, 2000b, 2002; Suh
et al., 1998; 1999; 2003; Place
et al., 2003; Liby
et al., 2005). Several potent derivatives of oleanolic acid were identified, including methyl-2-cyano-3,12-dioxooleana-1,9-dien-28-oic
acid (CDDO-Me; RTA 402). RTA 402 suppresses the induction of several important inflammatory
mediators, such as iNOS, COX-2, TNFα, and IFNγ, in activated macrophages. RTA 402
has also been reported to activate the Keap1/Nrf2/ARE signaling pathway resulting
in the production of several anti-inflammatory and antioxidant proteins, such as heme
oxygenase-1 (HO-1). These properties have made RTA 402 a candidate for the treatment
of neoplastic and proliferative diseases, such as cancer. The ability of this compound
and related molecules to treat and/or prevent kidney disease and cardiovascular disease
remains untested.
[0004] WO 2007/005879 reports that
nrf2 knockout mice suffer from a variety of increased sensitivities, for example, increased
susceptibility to cigarette smoke-induced emphysema and other lung-related diseases.
WO 2007/005879 proposes increasing Nrf2 biological activity or expression for the treatment or prevention
of various diseases associated with oxidative stress. Compounds contemplated to be
used as Nrf2 activating agents in this context are inter alia CDDO-Im and CDDO.
[0005] WO 2005/042002 reports, for example, the inhibition of FLIP (FLICE-Inhibitory Protein) activity
using antisense oligonucleotides. Proposed are methods of treating rheumatoid arthritis
and its symptoms by decreasing the activity of FLIP using a protein, nucleic acid,
or small molecule. Small molecules contemplated for use by this publication include
cyclohexamide, actinomycin D, 5-fluorouracil, doxorubicin, cisplatin, sodium butyrate,
bisindolylmaleimides, H7, calphostin C, chelerythrine chloride, CDDO, and PS-341.
[0006] Shin et al. (Mol. Cell. Biol. 2007 Oct; 27(20):7188-7197) reports that NRF2 regulates expression of aryl hydrocarbon receptor (AHR), subsequently
modulates several downstream events of the AHR signaling cascade, including (i) transcriptional
control of the xenobiotic metabolism genes
Cyp1a1 and
Cyp1b1 and (ii) inhibition of adipogenesis in mouse embryonic fibroblasts (MEFs). CDDO-Im
is reported to induce
Ahr in
Nrf2+/+ mouse embryonic fibroblasts (MEFs), but not in
Nrf2-/- MEFs. The authors speculate that NRF2 activators could be used to influence adipogenesis.
[0007] WO 2006/029221 discloses triterpenoid compounds with inter alia anticancer activity. The compounds
are obtainable from plants in the sapindaceae family, such as Xanthoceras sorbifolia,
other natural sources, or chemical synthesis.
[0008] WO 02/03996 proposes the use of a dammarane-type triterpenoid saponin or derivatives thereof
for treating or preventing conditions, which are related to reduced nitric oxide levels,
or which are ameliorable or preventable by augmentation of nitric oxide levels, within
the human body, or for promoting responses requiring enhanced nitric oxide levels
within the human body.
SUMMARY OF THE INVENTION
[0009] The present invention provides a compound for use in methods for improving renal
(kidney) function and/or for treating renal/kidney disease (RKD)
[0010] In one aspect of the present invention, a compound is provided for use in a method
of treating renal/kidney disease (RKD) in a subject comprising, the method comprising
administering to said subject a pharmaceutically effective amount of a compound having
the structure:

[0011] In some embodiments, a compound is provided for use in a method of treating RKD.
In some variations, the RKD is diabetic nephropathy (DN). In other variations, the
RKD results from a toxic insult, for example, wherein the toxic insult results from
an imaging agent or a drug. For example, the drug may be a chemotherapeutic agent.
In a further variation, the RKD results from ischemia/reperfusion injury. In yet a
further variation, the RKD results from diabetes or hypertension. In still further
variations, the RKD results from an autoimmune disease. In other variations, the RKD
is chronic RKD. In still other variations, the RKD is acute RKD.
[0012] In some embodiments, the subject has undergone or is undergoing dialysis. In some
embodiments, the subject has undergone or is a candidate to undergo kidney transplant.
In some embodiments, the subject has RKD and insulin resistance. In some variations
on the above embodiments, the subject has RKD, insulin resistance and endothelial
dysfunction. In some embodiments, the subject has RKD and diabetes. In some embodiments,
the subject has insulin resistance.
[0013] In some embodiments, the subject has RKD and endothelial dysfunction. In other embodiments,
the subject has RKD and cardiovascular disease. In some embodiments, the subject has
CVD. In some variations, the CVD results from endothelial dysfunction.
[0014] In some embodiments, the methods further comprise identifying a subject in need of
treatment of any of the diseases, dysfunctions, resistances or disorders listed herein.
In some embodiments, the subject has a family or patient history of any of the diseases,
dysfunctions, resistances or disorders listed herein. In some embodiments, the subject
exhibits symptoms of any of the diseases, dysfunctions, resistances or disorders listed
herein.
[0015] In some embodiments, the compound is administered locally. In some embodiments, the
compound is administered systemically. In some embodiments, the compound is administered
orally, intraadiposally, intraarterially, intraarticularly, intracranially, intradermally,
intralesionally, intramuscularly, intranasally, intraocularally, intrapericardially,
intraperitoneally, intrapleurally, intraprostatically, intrarectally, intrathecally,
intratracheally, intratumorally, intraumbilically, intravaginally, intravenously,
intravesicularlly, intravitreally, liposomally, locally, mucosally, orally, parenterally,
rectally, subconjunctivally, subcutaneously, sublingually, topically, transbuccally,
transdermally, vaginally, in crèmes, in lipid compositions, via a catheter, via a
lavage, via continuous infusion, via infusion, via inhalation, via injection, via
local delivery, via localized perfusion, bathing target cells directly, or any combination
thereof. For example, in some variations, the compound is administered intravenously,
intra-arterially or orally. For example, in some variations, the compound is administered
orally.
[0016] In some embodiments, the compound is formulated as a hard or soft capsule, a tablet,
a syrup, a suspension, a solid dispersion, a wafer, or an elixir. In some variations,
the soft capsule is a gelatin capsule. In variations, the compound is formulated as
a solid dispersion. In some variations the hard capsule, soft capsule, tablet or wafer
further comprises a protective coating. In some variations, the formulated compound
comprises an agent that delays absorption. In some variations, the formulated compound
further comprises an agent that enhances solubility or dispersibility. In some variations,
the compound is dispersed in a liposome, an oil in water emulsion or a water in oil
emulsion.
[0017] In some embodiments, the pharmaceutically effective amount is a daily dose from about
0.1 mg to about 500 mg of the compound. In some variations, the daily dose is from
about 1 mg to about 300 mg of the compound. In some variations, the daily dose is
from about 10 mg to about 200 mg of the compound. In some variations, the daily dose
is about 25 mg of the compound. In other variations, the daily dose is about 75 mg
of the compound. In still other variations, the daily dose is about 150 mg of the
compound. In further variations, the daily dose is from about 0.1 mg to about 30 mg
of the compound. In some variations, the daily dose is from about 0.5 mg to about
20 mg of the compound. In some variations, the daily dose is from about 1 mg to about
15 mg of the compound. In some variations, the daily dose is from about 1 mg to about
10 mg of the compound. In some variations, the daily dose is from about 1 mg to about
5 mg of the compound.
[0018] In some embodiments, the pharmaceutically effective amount is a daily dose is 0.01
- 25 mg of compound per kg of body weight. In some variations, the daily dose is 0.05
- 20 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 10 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 5 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 2.5 mg of compound per kg of body weight.
[0019] In some embodiments, the pharmaceutically effective amount is administered in a single
dose per day. In some embodiments, the pharmaceutically effective amount is administered
in two or more doses per day.
[0020] In some embodiments, the treatment method further comprises a second therapy. In
some variations, the second therapy comprises administering to said subject a pharmaceutically
effective amount of a second drug. In some embodiments, the second drug is a cholesterol
lowering drug, an anti-hyperlipidemic, a calcium channel blocker, an anti-hypertensive,
or an HMG-CoA reductase inhibitor. Non-limiting examples of second drugs are amlodipine,
aspirin, ezetimibe, felodipine, lacidipine, lercanidipine, nicardipine, nifedipine,
nimodipine, nisoldipine and nitrendipine. Further non-limiting examples of second
drugs are atenolol, bucindolol, carvedilol, clonidine, doxazosin, indoramin, labetalol,
methyldopa, metoprolol, nadolol, oxprenolol, phenoxybenzamine, phentolamine, pindolol,
prazosin, propranolol, terazosin, timolol and tolazoline. In some variations, the
second drug is a statin. Non-limiting examples of statins are atorvastatin, cerivastatin,
fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin.
In some variations, the second drug is a dipeptidyl peptidase-4 (DPP-4) inhibitor.
Non-limiting examples of DPP-4 inhibitors are sitagliptin, vildagliptin, SYR-322,
BMS 477118 and GSK 823093. In some variations, the second drug is a biguanide. For
example, the biguanide can be metformin. In some variations, the second drug is a
thiazolidinedione (TZD). Non-limiting examples of TZDs are pioglitazone, rosiglitazone
and troglitazone. In some variations, the second drug is a sulfonylurea derivative.
Non-limiting examples of sulfonyl urea derivatives are tolbutamide, acetohexamide,
tolazamide, chlorpropamide, glipizide, glyburide, glimepiride and gliclazide. In some
variations, the second drug is a meglitinide. Non-limiting examples of meglitinides
include repaglinide, mitiglinide and nateglinide. In some variations, the second drug
is insulin. In some variations, the second drug is an alpha-glucosidase inhibitor.
Non-limiting examples of alpha-glucosidase inhibitors are acarbose, miglitol and voglibose.
In some variations, the second drug is a glucagon-like peptide-1 analog. Non-limiting
examples of glucagon-like peptide-1 analogs are exenatide and liraglutide. In some
variations, the second drug is a gastric inhibitory peptide analog. In some variations,
the second drug is a GPR40 agonist. In some variations, the second drug is a GPR119
agonist. In some variations the second drug is a GPR30 agonist. In some variations,
the second drug is a glucokinase activator. In some variations, the second drug is
a glucagon receptor antagonist. In some variations, the second drug is an amylin analog.
A non-limiting example of an amylin analog is pramlintide. In some variations, the
second drug is an IL-1β receptor antagonist. A non-limiting examples of a IL-1β receptor
antagonist is anakinra. In some variations, the second drug is an endocannabinoid
receptor antagonist or inverse agonist. A non-limiting example of a endocannabinoid
receptor antagonist or inverse agonist is rimonabant. In some variations, the second
drug is Orlistat. In some variations, the second drug is Sibutramine. In some variations,
the second drug is a growth factor. Non-limiting examples of growth factors are TGF-β1,
TGF-β2, TGF-β1.2, VEGF, insulin-like growth factor I or II, BMP2, BMP4, BMP7, a GLP-1
analog, a GIP analog, a DPP-IV inhibitor, a GPR119 agonist, a GPR40 agonist, gastrin,
EGF, betacellulin, KGF, NGF, insulin, growth hormone, HGF, an FGF, an FGF homologue,
PDGF, Leptin, prolactin, placental lactogen, PTHrP, activin, inhibin, and INGAP. Further
non-limiting examples of growth factors are parathyroid hormone, calcitonin, interleukin-6,
and interleukin-11.
[0021] In some embodiments, the subject is a primate. In some variations, the primate is
a human. In other variations, the subject is a cow, horse, dog, cat, pig, mouse, rat
or guinea pig.
[0022] In some embodiments, at least a portion of the CDDO-Me is present as a polymorphic
form, wherein the polymorphic form is a crystalline form having an X-ray diffraction
pattern (CuKα) comprising significant diffraction peaks at about 8.8, 12.9, 13.4,
14.2 and 17.4 °2θ. In non-limiting examples, the X-ray diffraction pattern (CuKα)
is substantially as shown in FIG. 12A or FIG. 12B. In other variations, at least a
portion of the CDDO-Me is present as a polymorphic form, wherein the polymorphic form
is an amorphous form having an X-ray diffraction pattern (CuKα) with a halo peak at
approximately 13.5 °2θ, substantially as shown in FIG. 12C, and a T
g. In some variations, the compound is an amorphous form. In some variations, the compound
is a glassy solid form of CDDO-Me, having an X-ray powder diffraction pattern with
a halo peak at about 13.5 °2θ, as shown in FIG. 12C, and a T
g. In some variations, the T
g value falls within a range of about 120 °C to about 135 °C. In some variations, the
T
g value is from about 125 °C to about 130 °C.
[0023] In some variations of the above methods, the compound is substantially free from
optical isomers thereof. In some variations of the above methods, the compound is
in the form of a pharmaceutically acceptable salt. In other variations of the above
methods, the compound is not a salt.
[0024] In some embodiments, the compound is formulated as a pharmaceutical composition comprising
(i) a therapeutically effective amount of the compound and (ii) an excipient is selected
from the group consisting of (A) a carbohydrate, carbohydrate derivative, or carbohydrate
polymer, (B) a synthetic organic polymer, (C) an organic acid salt, (D) a protein,
polypeptide, or peptide, and (E) a high molecular weight polysaccharide. In some variations,
the excipient is a synthetic organic polymer. In some variations, the excipient is
selected from the group consisting of a hydroxpropyl methyl cellulose, a poly[1-(2-oxo-1-pyrrolidinyl)ethylene
or copolymer thereof, and a methacrylic acid - methylmethacrylate copolymer. In some
variations, the excipient is hydroxpropyl methyl cellulose phthalate ester. In some
variations, the excipient is PVP/VA. In some variations, the excipient is a methacrylic
acid - ethyl acrylate copolymer (1:1). In some variations, the excipient is copovidone.
[0025] Any embodiment discussed herein with respect to one aspect of the invention applies
to other aspects of the invention as well, unless specifically noted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The following drawings form part of the present specification and are included to
further demonstrate certain aspects of the present invention. The invention may be
better understood by reference to one or more of these drawings in combination with
the detailed description of specific embodiments presented herein.
FIGS. 1a-d - RTA 402 reduces renal damage following ischemia-reperfusion. Mice were administered RTA 402 at 2 mg/kg or simply the vehicle (sesame oil) daily
by oral gavage beginning on Day 2. On Day 0, a clamp was placed on the left renal
artery for 17 minutes and then removed to induce ischemia-reperfusion. (FIG. 1a) On
Day 1, blood was collected from animals that were subjected to clamping and "sham"
control animals that underwent surgery without clamping of the renal artery. Blood
urea nitrogen (BUN) levels were measured as a surrogate for renal damage. (FIGS. 1b-d)
Sections of kidneys from RTA 402-treated or vehicle-treated mice were scored for histological
damage (FIGS. 1b & 1d) and inflammation (FIG. 1c). (FIG. 1d) Black arrows (vehicle
group) show two of many severely damaged tubules in the outer medulla. Red arrows
(RTA 402 group) show two of many undamaged tubules in the outer medulla.
FIGS. 2a-c - RTA 402 reduces cisplatin-induced renal toxicity. Rats were administered RTA 402 at 10 mg/kg or simply the vehicle (sesame oil) every
day by oral gavage beginning on Day -1. On Day 0, the rats received an intravenous
injection of cisplatin at 6 mg/kg. Blood samples were drawn on the indicated days
and the levels of creatinine (FIG. 2a) and blood urea nitrogen (BUN) (FIG. 2b) were
measured as markers of renal damage. A statistically significant difference was observed
between the vehicle-treated and RTA 402-treated groups on Day 3 (creatinine) and Day
5 (creatinine and BUN). (FIG. 2c) Less damage to the proximal tubules is observed
in RTA 402-treated animals compared to vehicle-treated animals.
FIGS. 3a-d - RTA 402 reduces serum creatinine levels in monkeys, dogs, and rats. (FIG. 3a) Cynomolgus monkeys were administered RTA 402 orally at the indicated doses
once daily for 28 days. The percent reduction of serum creatinine on Day 28 in RTA
402-treated monkeys relative to vehicle-treated control monkeys is shown. (FIG. 3b)
RTA 402 was administered orally to beagle dogs at the indicated doses daily for three
months. Control animals received vehicle (sesame oil). The percent change in serum
creatinine at the three-month time point relative to baseline is shown. (FIG. 3c)
Sprague-Dawley rats were administered RTA 402 orally at the indicated doses once daily
for a period of one month. The percent reduction of serum creatinine at study completion
in RTA 402-treated rats relative to vehicle-treated control rats is shown. (FIG. 3d)
Sprague-Dawley rats were administered the amorphous form of RTA 402 orally at the
indicated doses once daily for a period of three months. The percent reduction of
serum creatinine at study completion in RTA 402-treated rats relative to vehicle-treated
control rats is shown. Note: in FIGS. 3A, 3C and 3D, "% reduction" on the vertical
axis indicates percent change. For example, a reading of -15 on this axis indicates
a 15% reduction in serum creatinine.
FIGS. 4A-B - RTA 402 reduces serum creatinine levels and increases the estimated glomerular filtration
rate (eGFR) in human patients with cancer. FIG. 4A: Serum creatinine was measured in RTA 402-treated patients enrolled in a
Phase I clinical trial for the treatment of cancer. The patients were administered
RTA 402 (p.o.) once daily for 21 days at doses ranging from 5 to 1,300 mg/day. The
percent reduction of serum creatinine relative to baseline levels is shown for the
indicated study days. Significant decreases in serum creatinine levels were observed
on Days 15 and 21. FIG. 4B: The estimated glomerular filtration rate (eGFR) was calculated
for the patients in FIG. 4A. Significant improvements in the eGFR were observed in
both groups. All patients: n = 24; patients with baseline ≥ 1.5: n = 5. For FIGS.
4A and 4B, * indicates p ≤ 0.04; † indicates p = 0.01, and ‡ indicates p ≤ 0.01. Note: in FIG. 4A, "% Reduction from Baseline" on the vertical axis indicates
percent change. For example, a reading of -15 on this axis indicates a 15% reduction
in serum creatinine.
FIG. 5 - RTA 402 increases GFR in human patients with cancer. Estimated glomerular filtration rate (eGFR) was measured in RTA 402-treated patients
enrolled in a multi-month clinical trial for the treatment of cancer. All patients
(n = 11) dosed through six months were included in the analysis. The dosing information
for these patients is provided in Example 5, below.
FIG. 6 - RTA 402 Activity Correlates with Severity. Reduction of hemoglobin A1c is presented as a fraction of the initial baseline value.
Groups with higher baselines, e.g., mean baseline ≥ 7.0% A1c or ≥ 7.6% A1c, showed
greater reduction. The intent-to-treat (ITT) group includes all patients (n = 53),
including those starting at a normal A1c value.
FIG. 7 - RTA 402 Activity is Dose Dependent. Reduction of hemoglobin A1c is presented relative to the initial baseline value.
The bar graph shows mean results for all patients, all patients with baseline A1c
values ≥ 7.0%, individual dose cohorts from the ≥ 7.0% group, and patients with Stage
4 renal disease (GFR 15-29 mL/min), wherein n is the number of patients in each group.
FIG. 8 - RTA 402 Reduces Circulating Endothelial Cells (CECs) and iNOS-positive CECs. The change in the mean number of CECs in cells/mL is shown for intent-to-treat (ITT)
and elevated baseline groups, both before and after the 28 day RTA treatment. The
reduction for the Intent-to-treat group was approximately 20%, and the reduction in
the elevated baseline group (>5 CECs/ml) was approximately 33%. The fraction of iNOS-positive
CECs was reduced approximately 29%.
FIG. 9 - Reversible Dose Dependent GFR Increase in 28 Days. Treatment with RTA 402 increases GFR dose-dependently. All evaluable patients were
included. An improvement of >30% was noted in patients with Stage 4 renal disease.
FIGS. 10A-B - Reduction of Markers of Diabetic Nephropathy Severity and Outcome. Improvements in Adiponectin (FIG. 10A) and Angiotensin II (FIG. 10B), which are elevated
in diabetic nephropathy (DN) patients and correlate with renal disease severity. Adiponectin
predicts all-cause mortality and end stage renal disease in DN patients. All available
data included.
FIGS. 11A-C - RTA 402 Significantly Reduces Uremic Solutes. The graphs present mean changes in BUN (FIG. 11A), phosphorus (FIG. 11B), and uric
acid (FIG. 11C) for all patients and for those patients showing elevated baseline
values of a particular solute.
FIGS. 12A-C - X-ray Powder Diffraction (XRPD) Spectra of Forms A and B of RTA 402. FIG. 12A shows unmicronized Form A; FIG. 12B shows micronized Form A; FIG. 12C shows
Form B.
FIG. 13 - Modulated Differential Scanning Calorimetry (MDSC) Curve of Form A RTA 402. The section of the curve shown in the expanded view is consistent with a glass transition
temperature (Tg).
FIG. 14 - Modulated Differential Scanning Calorimetry (MDSC) Curve of Form B RTA 402. The section of the curve shown in the expanded view is consistent with a glass transition
temperature (Tg).
FIG. 15 - Improved Bioavailability of Form B (Amorphous) in Cynomolgus Monkeys. The figure shows a representative plot of the area under the curve for Form A and
Form B, following a 4.1 mg/kg oral administration to cynomolgus monkeys. Each data
point represents the mean plasma concentration of CDDO methyl ester in 8 animals.
Error bars represent the standard deviation within the sampled population.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
1. The Present Invention
[0027] The present invention concerns a compound for use in methods for the treatment and
prevention of renal disease.
III. Definitions
[0028] Atoms making up the compounds for use according to the present invention are intended
to include all isotopic forms of such atoms. Isotopes, as used herein, include those
atoms having the same atomic number but different mass numbers. By way of general
example and without limitation, isotopes of hydrogen include tritium and deuterium,
and isotopes of carbon include
13C and
14C. Similarly, it is contemplated that one or more carbon atom(s) of a compound may
be replaced by a silicon atom(s). Similarly, it is contemplated that one or more oxygen
atom(s) of a compound may be replaced by a sulfur or a selenium atom(s).
[0029] Any undefined valency on an atom of a structure shown in this application implicitly
represents a hydrogen atom bonded to the atom.
[0030] The use of the word "a" or "an," when used in conjunction with the term "comprising"
in the claims and/or the specification may mean "one," but it is also consistent with
the meaning of "one or more," "at least one," and "one or more than one."
[0031] Throughout this application, the term "about" is used to indicate that a value includes
the inherent variation of error for the device, the method being employed to determine
the value, or the variation that exists among the study subjects.
[0032] The terms "comprise," "have" and "include" are open-ended linking verbs. Any forms
or tenses of one or more of these verbs, such as "comprises," "comprising," "has,"
"having," "includes" and "including," are also open-ended. For example, any method
that "comprises," "has" or "includes" one or more steps is not limited to possessing
only those one or more steps and also covers other unlisted steps.
[0033] The term "effective," as that term is used in the specification and/or claims, means
adequate to accomplish a desired, expected, or intended result.
[0034] The term "hydrate" when used as a modifier to a compound means that the compound
has less than one (
e.g., hemihydrate), one (
e.g., monohydrate), or more than one (
e.g., dihydrate) water molecules associated with each compound molecule, such as in solid
forms of the compound.
[0035] As used herein, the term "IC
50" refers to an inhibitory dose which is 50% of the maximum response obtained.
[0036] An "isomer" of a first compound is a separate compound in which each molecule contains
the same constituent atoms as the first compound, but where the configuration of those
atoms in three dimensions differs.
[0037] As used herein, the term "patient" or "subject" refers to a living mammalian organism,
such as a human, monkey, cow, sheep, goat, dog, cat, mouse, rat, guinea pig, or transgenic
species thereof. In certain embodiments, the patient or subject is a primate. Non-limiting
examples of human subjects are adults, juveniles, infants and fetuses.
[0038] "Pharmaceutically acceptable" means that which is useful in preparing a pharmaceutical
composition that is generally safe, non-toxic and neither biologically nor otherwise
undesirable and includes that which is acceptable for veterinary use as well as human
pharmaceutical use.
[0039] "Pharmaceutically acceptable salts" means salts of compounds for use according to
the present invention which are pharmaceutically acceptable, as defined above, and
which possess the desired pharmacological activity. Such salts include acid addition
salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric
acid, nitric acid, phosphoric acid, and the like; or with organic acids such as 1,2-ethanedisulfonic
acid, 2-hydroxyethanesulfonic acid, 2-naphthalenesulfonic acid, 3-phenylpropionic
acid, 4,4'-methylenebis(3-hydroxy-2-ene-1-carboxylic acid), 4-methylbicyclo[2.2.2]oct-2-ene-1-carboxylic
acid, acetic acid, aliphatic mono- and dicarboxylicacids, aliphatic sulfuric acids,
aromatic sulfuric acids, benzenesulfonic acid, benzoic acid, camphorsulfonic acid,
carbonic acid, cinnamic acid, citric acid, cyclopentanepropionic acid, ethanesulfonic
acid, fumaric acid, glucoheptonic acid, gluconic acid, glutamic acid, glycolic acid,
heptanoic acid, hexanoic acid, hydroxynaphthoic acid, lactic acid, laurylsulfuric
acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid,
muconic acid,
o-(4-hydroxybenzoyl)benzoic acid, oxalic acid,
p-chlorobenzenesulfonic acid, phenyl-substituted alkanoic acids, propionic acid,
p-toluenesulfonic acid, pyruvic acid, salicylic acid, stearic acid, succinic acid,
tartaric acid, tertiarybutylacetic acid, trimethylacetic acid, and the like. Pharmaceutically
acceptable salts also include base addition salts which may be formed when acidic
protons present are capable of reacting with inorganic or organic bases. Acceptable
inorganic bases include sodium hydroxide, sodium carbonate, potassium hydroxide, aluminum
hydroxide and calcium hydroxide. Acceptable organic bases include ethanolamine, diethanolamine,
triethanolamine, tromethamine,
N-methylglucamine and the like. It should be recognized that the particular anion or
cation forming a part of any salt of this invention is not critical, so long as the
salt, as a whole, is pharmacologically acceptable. Additional examples of pharmaceutically
acceptable salts and their methods of preparation and use are presented in
Handbook of Pharmaceutical Salts: Properties, and Use (P. H. Stahl & C. G. Wermuth
eds., Verlag Helvetica Chimica Acta, 2002).
[0040] "Prevention" or "preventing" includes: (1) inhibiting the onset of a disease in a
subject or patient which may be at risk and/or predisposed to the disease but does
not yet experience or display any or all of the pathology or symptomatology of the
disease, and/or (2) slowing the onset of the pathology or symptomatology of a disease
in a subject or patient which may be at risk and/or predisposed to the disease but
does not yet experience or display any or all of the pathology or symptomatology of
the disease.
[0041] The term "saturated" when referring to an atom means that the atom is connected to
other atoms only by means of single bonds.
[0042] A "stereoisomer" or "optical isomer" is an isomer of a given compound in which the
same atoms are bonded to the same other atoms, but where the configuration of those
atoms in three dimensions differs. "Enantiomers" are stereoisomers of a given compound
that are mirror images of each other, like left and right hands. "Diastereomers" are
stereoisomers of a given compound that are not enantiomers.
[0043] "Therapeutically effective amount" or "pharmaceutically effective amount" means that
amount which, when administered to a subject or patient for treating a disease, is
sufficient to effect such treatment for the disease.
[0044] "Treatment" or "treating" includes (1) inhibiting a disease in a subject or patient
experiencing or displaying the pathology or symptomatology of the disease (
e.g., arresting further development of the pathology and/or symptomatology), (2) ameliorating
a disease in a subject or patient that is experiencing or displaying the pathology
or symptomatology of the disease (
e.g., reversing the pathology and/or symptomatology), and/or (3) effecting any measurable
decrease in a disease in a subject or patient that is experiencing or displaying the
pathology or symptomatology of the disease.
[0045] As used herein, the term "water soluble" means that the compound dissolves in water
at least to the extent of 0.010 mole/liter or is classified as soluble according to
literature precedence.
[0046] Other abbreviations used herein are as follows: DMSO, dimethyl sulfoxide; NO, nitric
oxide; iNOS, inducible nitric oxide synthase; COX-2, cyclooxygenase-2; NGF, nerve
growth factor; IBMX, isobutylmethylxanthine; FBS, fetal bovine serum; GPDH, glycerol
3-phosphate dehydrogenase; RXR, retinoid X receptor; TGF-β, transforming growth factor-β;
IFNγ or IFN-γ, interferon-γ; LPS, bacterial endotoxic lipopolysaccharide; TNFα or
TNF-α, tumor necrosis factor-α; IL-1β, interleukin-1β; GAPDH, glyceraldehyde-3-phosphate
dehydrogenase; MTBE, methyl-
tert-butylether; MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; TCA,
trichloroacetic acid; HO-1, inducible heme oxygenase.
IV. Synthetic Triterpenoids
[0047] Triterpenoids, biosynthesized in plants by the cyclization of squalene, are used
for medicinal purposes in many Asian countries; and some, like ursolic and oleanolic
acids, are known to be anti-inflammatory and anti-carcinogenic (Huang
et al., 1994; Nishino
et al., 1988). However, the biological activity of these naturally-occurring molecules is
relatively weak, and therefore the synthesis of new analogs to enhance their potency
was undertaken (Honda
et al., 1997; Honda
et al., 1998). Subsequent research has identified a number of synthetic compounds that have
improved activity as compared to the naturally-occurring triterpenoids.
[0048] The ongoing efforts for the improvement of anti-inflammatory and antiproliferative
activity of oleanolic and ursolic acid analogs led to the discovery of 2-cyano-3,12-dioxooleane-1,9(11)-dien-28-oic
acid (CDDO, RTA 402) and related compounds (
e.g., CDDO-Me, TP-225, CDDO-Im) (Honda
et al., 1997, 1998, 1999, 2000a, 2000b, 2002; Suh
et al., 1998; 1999; 2003; Place
et al., 2003; Liby
et al., 2005). In the case of inducing cytoprotective genes through Keap1-Nrf2-antioxidant
response element (ARE) signaling, a recent structure activity evaluation of 15 triterpenoids
noted the importance of Michael acceptor groups on both the A and C rings, a nitrile
group at C-2 of the A ring, and that substituents at C-17 affected pharmacodynamic
action
in vivo (Yates
et al., 2007).

In general, CDDO is the prototype for a large number of compounds in a family of agents
that have been shown useful in a variety of contexts. For example, CDDO-Me and CDDO-Im
are reported to possess the ability to modulate transforming growth factor-β (TGF-β)/Smad
signaling in several types of cells (Suh
et al., 2003; Minns
et al., 2004; Mix
et al., 2004). Both are known to be potent inducers of heme-oxygenase-1 and Nrf2/ARE signaling
(Liby
et al., 2005), and a series of synthetic triterpenoid (TP) analogs of oleanolic acid have
also been shown to be potent inducers of the phase 2 response, that is elevation of
NAD(P)H-quinone oxidoreductase and heme oxygenase 1 (HO-1), which is a major protector
of cells against oxidative and electrophile stress (Dinkova-Kostova
et al., 2005). Like previously identified phase 2 inducers, the TP analogs were shown to
use the antioxidant response element-Nrf2-Keap1 signaling pathway.
[0049] RTA 402 (bardoxolone methyl), the compound for use with the methods of this invention,
is an Antioxidant Inflammation Modulator (AIM) in clinical development for inflammation
and cancer-related indications that inhibits immune-mediated inflammation by restoring
redox homeostasis in inflamed tissues. It induces the cytoprotective transcription
factor Nrf2 and suppresses the activities of the pro-oxidant and pro-inflammatory
transcription factors NF-κB and STAT3.
In vivo, RTA 402 has demonstrated significant single agent anti-inflammatory activity in several
animal models of inflammation such as renal damage in the cisplatin model and acute
renal injury in the ischemia-reperfusion model. In addition, significant reductions
in serum creatinine have been observed in patients treated with RTA 402.
[0050] In one aspect of the invention, the compound may be used for treating a subject having
a renal disease or condition caused by elevated levels of oxidative stress in one
or more tissues. The oxidative stress may be accompanied by either acute or chronic
inflammation. The oxidative stress may be caused by acute exposure to an external
agent such as ionizing radiation or a cytotoxic chemotherapy agent (
e.g., doxorubicin), by trauma or other acute tissue injury, by ischemia/reperfusion injury,
by poor circulation or anemia, by localized or systemic hypoxia or hyperoxia, or by
other abnormal physiological states such as hyperglycemia or hypoglycemia.
[0051] Accordingly, in pathologies involving oxidative stress alone or oxidative stress
exacerbated by inflammation, treatment may comprise administering to a subject a therapeutically
effective amount of a compound, such as those described above or throughout this specification.
Treatment may be administered preventively in advance of a predictable state of oxidative
stress (
e.g., organ transplantation or the administration of therapy to a cancer patient), or
it may be administered therapeutically in settings involving established oxidative
stress and inflammation.
Table 1 summarizes
in vitro results for several of compounds in which RAW264.7 macrophages were pre-treated with
DMSO or drugs at various concentrations (nM) for 2 hours, then treated with 20 ng/ml
IFNγ for 24 hours. NO concentration in media was determined using a Griess reagent
system; cell viability was determined using WST-1 reagent. NQO1 CD represents the
concentration required to induce a two-fold increase in the expression of NQO1, an
Nrf2-regulated antioxidant enzyme, in Hepa1c1c7 murine hepatoma cells (Dinkova-Kostova
et al., 2005). All these results are orders of magnitude more active than, for example, the
parent oleanolic acid molecule.
Table 1. Suppression of IFNγ-induced NO production.
| Working ID |
RAW264.7 (20 ng/ml IFNγ) |
Hepa1c1c7 cells |
| NO IC50 |
WST-1 IC50 |
NQO1 CD |
| RTA 401 (comparative example) |
∼10 nM |
> 200 nM |
2.3 nM |
| RTA 402 |
2.2 nM |
80 nM |
1.0 nM |
| RTA 403 (comparative example) |
∼0.6 nM |
100 nM |
3.3 nM |
| RTA 404 (comparative example) |
5.8 nM |
100 nM |
n/a |
| RTA 405 (comparative example) |
6 nM |
∼200 nM |
n/a |
| TP-225 (comparative example) |
∼0.4 nM |
75 nM |
0.28 nM |
[0052] The synthesis of CDDO-MA is discussed in Honda
et al. (2002). The syntheses of CDDO-EA and CDDO-TFEA are presented in Yates
et al. (2007), which is shown in the Scheme 1 below.

V. Polymorphic Forms of CDDO-Me
[0053] Polymorphic forms of the compound,
e.g., Forms A and B of CDDO-Me, may be used in accordance with the inventions. Form B
displays a bioavailability that is surprisingly better than that of Form A (FIG. 15).
Specifically the bioavailability of Form B was higher than that of Form A CDDO-Me
in monkeys when the monkeys received equivalent dosages of the two forms orally, in
gelatin capsules (
U.S. Application No. 12/191,176, filed August 13, 2008).
[0054] "Form A" of CDDO-Me (RTA 402) is unsolvated (non-hydrous) and can be characterized
by a distinctive crystal structure, with a space group of P4
3 2
12 (no. 96) unit cell dimensions of a = 14.2 Å, b = 14.2 Å and c = 81.6 Å, and by a
packing structure, whereby three molecules are packed in helical fashion down the
crystallographic
b axis. In some embodiments, Form A can also be characterized by X-ray powder diffraction
(XRPD) pattern (CuKα) comprising significant diffraction peaks at about 8.8, 12.9,
13.4, 14.2 and 17.4 °2θ. In some variations, the X-ray powder diffraction of Form
A is substantially as shown in FIG. 12A or FIG. 12B.
[0055] Unlike Form A, "Form B" of CDDO-Me is in a single phase but lacks such a defined
crystal structure. Samples of Form B show no long-range molecular correlation,
i.e., above roughly 20 Å. Moreover, thermal analysis of Form B samples reveals a glass
transition temperature (T
g) in a range from about 120 °C to about 130 °C (FIG. 14). In contrast, a disordered
nanocrystalline material does not display a T
g but instead only a melting temperature (T
m), above which crystalline structure becomes a liquid. Form B is typified by an XRPD
spectrum (FIG 12C) differing from that of Form A (FIG. 12A or FIG. 12B). Since it
does not have a defined crystal structure, Form B likewise lacks distinct XRPD peaks,
such as those that typify Form A, and instead is characterized by a general "halo"
XRPD pattern. In particular, the non-crystalline Form B falls into the category of
"X-ray amorphous" solids because its XRPD pattern exhibits three or fewer primary
diffraction halos. Within this category, Form B is a "glassy" material.
[0056] Form A and Form B of CDDO-Me are readily prepared from a variety of solutions of
the compound. For example, Form B can be prepared by fast evaporation or slow evaporation
in MTBE, THF, toluene, or ethyl acetate. Form A can be prepared in several ways, including
via fast evaporation, slow evaporation, or slow cooling of a CDDO-Me solution in ethanol
or methanol. Preparations of CDDO-Me in acetone can produce either Form A, using fast
evaporation, or Form B, using slow evaporation.
[0057] Various means of characterization can be used together to distinguish Form A and
Form B CDDO-Me from each other and from other forms of CDDO-Me. Illustrative of the
techniques suitable for this purpose are solid state Nuclear Magnetic Resonance (NMR),
X-ray powder diffraction (compare FIGS. 12A & B with FIG. 12C), X-ray crystallography,
Differential Scanning Calorimetry (DSC) (compare FIG. 13 with FIG. 14), dynamic vapor
sorption/desorption (DVS), Karl Fischer analysis (KF), hot stage microscopy, modulated
differential screening calorimetry, FT-IR, and Raman spectroscopy. In particular,
analysis of the XRPD and DSC data can distinguish Form A, Form B, and a hemibenzenate
forms of CDDO-Me (
U.S. Application No. 12/191,176, filed August 13, 2008.)
VI. Use of Triterpenoids for the Treatment of Chronic Kidney Disease, Insulin Resistance/Diabetes
and Endothelial Dysfunction/Cardiovascular Disease
[0059] The compound may be used for treating various aspects of renal/kidney disease, including
both acute and chronic indications. In general, the method will comprise administering
to the subjects pharmaceutically effective amounts of a compound.
[0060] Inflammation contributes significantly to the pathology of chronic kidney disease
(CKD). There is also a strong mechanistic link between oxidative stress and renal
dysfunction. The NF-κB signaling pathway plays an important role in the progression
of CKD as NF-κB regulates the transcription of MCP-1, a chemokine that is responsible
for the recruitment of monocytes/macrophages resulting in an inflammatory response
that ultimately injures the kidney (Wardle, 2001). The Keap1/Nrf2/ARE pathway controls
the transcription of several genes encoding antioxidant enzymes, including heme oxygenase-1
(HO-1). Ablation of the Nrf2 gene in female mice results in the development of lupus-like
glomerular nephritis (Yoh
et al., 2001; Ma
et al., 2006). Furthermore, several studies have demonstrated that HO-1 expression is induced
in response to renal damage and inflammation and that this enzyme and its products
- bilirubin and carbon monoxide - play a protective role in the kidney (Nath
et al., 2006).
[0061] The glomerulus and the surrounding Bowman's capsule constitute the basic functional
unit of the kidney. Glomerular filtration rate (GFR) is the standard measure of renal
function. Creatinine clearance is commonly used to measure GFR. However, the level
of serum creatinine is commonly used as a surrogate measure of creatinine clearance.
For instance, excessive levels of serum creatinine are generally accepted to indicate
inadequate renal function and reductions in serum creatinine over time are accepted
as an indication of improved renal function. Normal levels of creatinine in the blood
are approximately 0.6 to 1.2 milligrams (mg) per deciliter (dl) in adult males and
0.5 to 1.1 milligrams per deciliter in adult females.
[0062] Acute kidney injury (AKI) can occur following ischemia-reperfusion, treatment with
certain pharmacological agents such as cisplatin and rapamycin, and intravenous injection
of radiocontrast media used in medical imaging. As in CKD, inflammation and oxidative
stress contribute to the pathology of AKI. The molecular mechanisms underlying radiocontrast-induced
nephropathy (RCN) are not well understood; however, it is likely that a combination
of events including prolonged vasoconstriction, impaired kidney autoregulation, and
direct toxicity of the contrast media all contribute to renal failure (Tumlin
et al., 2006). Vasoconstriction results in decreased renal blood flow and causes ischemia-reperfusion
and the production of reactive oxygen species. HO-1 is strongly induced under these
conditions and has been demonstrated to prevent ischemia-reperfusion injury in several
different organs, including the kidney (Nath
et al., 2006). Specifically, induction of HO-1 has been shown to be protective in a rat model
of RCN (Goodman
et al., 2007). Reperfusion also induces an inflammatory response, in part though activation
of NF-κB signaling (Nichols, 2004). Targeting NF-κB has been proposed as a therapeutic
strategy to prevent organ damage (Zingarelli
et al., 2003).
[0063] Without being bound by theory, the potency of the compound RTA 402, is largely derived
from the addition of α,β-unsaturated carbonyl groups. In
in vitro assays, most activity of the compounds can be abrogated by the introduction of dithiothreitol
(DTT), N-acetyl cysteine (NAC), or glutathione (GSH); thiol containing moieties that
interact with α,β-unsaturated carbonyl groups (Wang
et al., 2000; Ikeda
et al., 2003; 2004; Shishodia
et al., 2006). Biochemical assays have established that RTA 402 directly interacts with a
critical cysteine residue (C179) on IKKβ (see below) and inhibits its activity (Shishodia
et al., 2006; Ahmad
et al., 2006). IKKβ controls activation of NF-κB through the "classical" pathway which involves
phosphorylation-induced degradation of IκB resulting in release of NF-κB dimers to
the nucleus. In macrophages, this pathway is responsible for the production of many
pro-inflammatory molecules in response to TNFα and other pro-inflammatory stimuli.
[0064] RTA 402 also inhibits the JAK/STAT signaling pathway at multiple levels. JAK proteins
are recruited to transmembrane receptors (
e.g., IL-6R) upon activation by ligands such as interferons and interleukins. JAKs then
phosphorylate the intracellular portion of the receptor causing recruitment of STAT
transcription factors. The STATs are then phosphorylated by JAKs, form dimers, and
translocate to the nucleus where they activate transcription of several genes involved
in inflammation. RTA 402 inhibits constitutive and IL-6-induced STAT3 phosphorylation
and dimer formation and directly binds to cysteine residues in STAT3 (C259) and in
the kinase domain of JAK1 (C1077). Biochemical assays have also established that the
triterpenoids directly interact with critical cysteine residues on Keap1 (Dinkova-Kostova
et al., 2005). Keap1 is an actin-tethered protein that keeps the transcription factor Nrf2
sequestered in the cytoplasm under normal conditions (Kobayashi & Yamamoto, 2005).
Oxidative stress results in oxidation of the regulatory cysteine residues on Keap1
and causes the release of Nrf2. Nrf2 then translocates to the nucleus and binds to
antioxidant response elements (AREs) resulting in transcriptional activation of many
antioxidant and anti-inflammatory genes. Another target of the Keap1/Nrf2/ARE pathway
is heme oxygenase 1 (HO-1). HO-1 breaks down heme into bilirubin and carbon monoxide
and plays many antioxidant and anti-inflammatory roles (Maines & Gibbs, 2005). HO-1
has recently been shown to be potently induced by the triterpenoids (Liby
et al., 2005), including RTA 402. RTA 402 and many structural analogs have also been shown
to be potent inducers of the expression of other Phase 2 proteins (Yates
et al., 2007).
[0065] RTA 402 is a potent inhibitor of NF-κB activation. Furthermore, RTA 402 activates
the Keap1/Nrf2/ARE pathway and induces expression of HO-1. As described below, RTA
402 has demonstrated activity in two animal models of AKI. Furthermore, reduced serum
creatinine levels and improvement of glomerular filtration have been observed in the
majority of human patients that have been treated with RTA 402 (see Examples below).
Significant improvements have now been observed in a Phase II study of patients with
diabetic nephropathy. The findings indicate that RTA 402 may be used to improve renal
function in patients with diabetic nephropathy through suppression of renal inflammation
and improvement of glomerular filtration.
[0066] As noted above, both diabetes and essential hypertension are major risk factors for
the development of chronic kidney disease and, ultimately, renal failure. Both of
these conditions, along with indicators of systemic cardiovascular disease such as
hyperlipidemia, are frequently present in the same patient, especially if that patient
is clinically obese. Although the unifying factors are not completely understood,
dysfunction of the vascular endothelium has been implicated as a significant pathological
factor in systemic cardiovascular disease, chronic kidney disease, and diabetes (see,
e.g., Zoccali, 2006). Acute or chronic oxidative stress in vascular endothelial cells has
been implicated in the development of endothelial dysfunction, and is strongly associated
with chronic inflammatory processes. Therefore, an agent capable of relieving oxidative
stress and concomitant inflammation in the vascular endothelium may alleviate dysfunction
and restore endothelial homeostasis. Without being bound by theory, compounds for
use according to the invention, by stimulating Nrf2-regulated endogenous antioxidant
mechanisms, have shown the highly unusual ability to improve parameters related to
renal function (
e.g., serum creatinine and estimated glomerular filtration rate), glycemic control and
insulin resistance (
e.g., hemoglobin A1c), and systemic cardiovascular disease (
e.g., circulating endothelial cells) in patients having abnormal clinical values for
these parameters. Currently, combination therapy is typically required in such patients
to achieve improvements in measures of glycemic control and cardiovascular disease,
including the use of angiotensin-converting enzyme inhibitors or angiotensin II receptor
blockers to alleviate hypertension and slow the progression of chronic kidney disease.
By achieving simultaneous and clinically meaningful improvements in all of these parameters,
especially measures of renal function, compounds for use according to the invention
represent a significant improvement over currently available therapies. In some aspects,
the compounds for use according to the present invention may be used to treat a combination
of the above conditions as a single therapy, or in combination with fewer additional
therapies than would currently be used.
[0067] These findings also indicate that administration of RTA 402 may be used to protect
patients from kidney damage such as from exposure to radiocontrast agents, as in the
case of radiocontrast-induced nephropathy (RCN), as well as in other contexts. In
one aspect, the compounds for use according to this invention may be used to treat
ischemia-reperfusion- and/or chemotherapy-induced acute renal injury. For example,
the results shown in Examples 2 and 3 below demonstrate that RTA 402 is protective
in animal models of ischemia-reperfusion- and chemotherapy-induced acute renal injury.
[0068] Serum creatinine has been measured in several animal models treated with RTA 402.
Significant reductions of serum creatinine levels relative to baseline levels or levels
in control animals have been observed in cynomolgus monkeys, beagle dogs, and Sprague-Dawley
rats (FIGS. 3A-D). This effect has been observed in rats with both forms of RTA 402
(crystalline and amorphous).
[0069] RTA 402 reduces serum creatinine in patients. For example, improvements were observed
in cancer patients receiving RTA 402. In humans, nephrotoxicity is a dose-limiting
side-effect of treatment with cisplatin. Cisplatin-induced damage to the proximal
tubules is thought to be mediated by increased inflammation, oxidative stress, and
apoptosis (Yao
et al., 2007). Serum creatinine has also been measured in patients with chronic kidney disease
(CKD) enrolled in an open label Phase II clinical trial of RTA 402 (Example 6). This
study was designed with multiple endpoints, in categories of insulin resistance, endothelial
dysfunction/CVD, and CKD, including measurements of hemoglobin A1c (A1c), a widely
used phase 3 endpoint for glycemic control.
[0070] A1c is a minor component of hemoglobin to which glucose is bound. A1c also is referred
to as glycosylated or glucosylated hemoglobin. A1c may be separated by charge and
size from the other hemoglobin A components in blood using high performance liquid
chromatography (HPLC). Because A1c is not affected by short-term fluctuations in blood
glucose concentrations, for example, due to meals, blood can be drawn for A1c testing
without regard to when food was eaten. In healthy, non-diabetic patients the A1c level
is less than 7% of total hemoglobin. The normal range is 4-5.9%. In poorly controlled
diabetes, it can be 8.0% or above. It has been demonstrated that the complications
of diabetes can be delayed or prevented if the A1c level can be kept close to 7%.
[0071] Recently approved agents typically only reduce A1c levels an amount of 0.4 to 0.80
over six months of treatment, with 28 day improvements typically smaller. The table
below shows six-month Hemoglobin A1c Reductions by two approved agents, sitagliptin
and pramlintide acetate (Aschner
et al., 2006; Goldstein
et al., 2007; Pullman
et al., 2006).
| Drug |
Duration of DM (years) |
Study Design |
Mean A1c |
Change |
| Sitagliptin |
4.3 |
+/placebo with A1c ≥ 7.0 |
8.0 |
-0.8 |
| 4.4 |
+/metformin with A1c ≥ 7.5 |
8.9 |
-0.7 |
| 6.1 |
pioglitazone +/sitagliptin; A1c ≥ 7.0 |
8.1 |
-0.7 |
| Pramlintide acetate |
13 |
+/insulin |
9.1 |
-0.4 |
[0072] In comparison, RTA 402 reduces A1c in 28 days in refractory diabetics on top of standard
of care. The treatment showed an intent-to-treat reduction of 0.34 (n = 21) and an
elevated baseline (≥ 7.0 at baseline) reduction of 0.50 (n = 16). These results are
presented in greater detail in the Examples section below. See also FIGS. 6 and 7.
[0073] The compounds for use according to this invention may be used to improve renal function.
As shown in Example 6, treatment using RTA 402 has been shown to improve six measures
of renal function and status, including serum creatinine based eGFR, creatinine clearance,
BUN, Cystatin C, Adiponectin, and Angiotensin II. RTA 402 was shown to increase GFR
in a dose-dependent manner and with high response rate (86%; n = 22). As also shown
in FIG. 9, the 28 day GFR improvements were reversible after the drug was withdrawn.
[0074] In some embodiments, treatment methods result in improved levels of Adiponectin and/or
Angiotensin II. Adiponectin and Angiotensin II are typically elevated in DN patients
and correlate with renal disease severity. Adiponectin (also referred to as Acrp30,
apM1) is a hormone known to modulate a number of metabolic processes, including glucose
regulation and fatty acid catabolism. Adiponectin is secreted from adipose tissue
into the bloodstream and is abundant in plasma relative to many other hormones. Levels
of the hormone are inversely correlated with body fat percentage in adults, while
the association in infants and young children is more unclear. The hormone plays a
role in the suppression of the metabolic derangements that may result in type 2 diabetes,
obesity, atherosclerosis and non-alcoholic fatty liver disease (NAFLD). Adiponectin
can be used to predict all-cause mortality and end stage renal disease in DN patients.
[0075] The treatment methods have been found to reduce matrix metallopeptidase 9 (MMP-9),
soluble adhesion molecules and tumor necrosis factor (TNFα) in most patients. High
levels of these typically correlate with poor cardiovascular outcomes.
VII. Pharmaceutical Formulations and Routes of Administration
[0076] Administration of the compound to a patient will follow general protocols for the
administration of pharmaceuticals, taking into account the toxicity, if any, of the
drug. It is expected that the treatment cycles would be repeated as necessary.
[0077] The compound of the present invention may be administered by a variety of methods,
e.g., orally or by injection (
e.g. subcutaneous, intravenous, intraperitoneal,
etc.). Depending on the route of administration, the active compound may be coated by
a material to protect the compound from the action of acids and other natural conditions
which may inactivate the compound. It may also be administered by continuous perfusion/infusion
of a disease or wound site. Specific examples of formulations, including a polymer-based
dispersion of CDDO-Me that showed improved oral bioavailability, are provided in
U.S. Application No. 12/191,176, filed August 13, 2008. It will be recognized by those skilled in the art that other methods of manufacture
may be used to produce dispersions of the present invention with equivalent properties
and utility (see Repka
et al., 2002 and references cited therein). Such alternative methods include but are not
limited to solvent evaporation, extrusion, such as hot melt extrusion, and other techniques.
[0078] To administer the therapeutic compound by other than parenteral administration, it
may be necessary to coat the compound with, or co-administer the compound with, a
material to prevent its inactivation. For example, the therapeutic compound may be
administered to a patient in an appropriate carrier, for example, liposomes, or a
diluent. Pharmaceutically acceptable diluents include saline and aqueous buffer solutions.
Liposomes include water-in-oil-in-water CGF emulsions as well as conventional liposomes
(Strejan
et al., 1984).
[0079] The therapeutic compound may also be administered parenterally, intraperitoneally,
intraspinally, or intracerebrally. Dispersions may be prepared in,
e.g., glycerol, liquid polyethylene glycols, mixtures thereof, and in oils. Under ordinary
conditions of storage and use, these preparations may contain a preservative to prevent
the growth of microorganisms.
[0080] Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions
(where water soluble) or dispersions and sterile powders for the extemporaneous preparation
of sterile injectable solutions or dispersion. In all cases, the composition must
be sterile and must be fluid to the extent that easy syringability exists. It must
be stable under the conditions of manufacture and storage and must be preserved against
the contaminating action of microorganisms such as bacteria and fungi. The carrier
may be a solvent or dispersion medium containing, for example, water, ethanol, polyol
(such as, glycerol, propylene glycol, and liquid polyethylene glycol, and the like),
suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained,
for example, by the use of a coating such as lecithin, by the maintenance of the required
particle size in the case of dispersion and by the use of surfactants. Prevention
of the action of microorganisms can be achieved by various antibacterial and antifungal
agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and
the like. In many cases, it will be preferable to include isotonic agents, for example,
sugars, sodium chloride, or polyalcohols such as mannitol and sorbitol, in the composition.
Prolonged absorption of the injectable compositions can be brought about by including
in the composition an agent which delays absorption, for example, aluminum monostearate
or gelatin.
[0081] Sterile injectable solutions can be prepared by incorporating the therapeutic compound
in the required amount in an appropriate solvent with one or a combination of ingredients
enumerated above, as required, followed by filtered sterilization. Generally, dispersions
are prepared by incorporating the therapeutic compound into a sterile carrier which
contains a basic dispersion medium and the required other ingredients from those enumerated
above. In the case of sterile powders for the preparation of sterile injectable solutions,
the preferred methods of preparation are vacuum drying and freeze-drying which yields
a powder of the active ingredient (
i.e., the therapeutic compound) plus any additional desired ingredient from a previously
sterile-filtered solution thereof.
[0082] The therapeutic compound can be orally administered, for example, with an inert diluent
or an assimilable edible carrier. The therapeutic compound and other ingredients may
also be enclosed in a hard or soft shell gelatin capsule, compressed into tablets,
or incorporated directly into the subject's diet. For oral therapeutic administration,
the therapeutic compound may be incorporated with excipients and used in the form
of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups,
wafers, and the like. The percentage of the therapeutic compound in the compositions
and preparations may, of course, be varied. The amount of the therapeutic compound
in such therapeutically useful compositions is such that a suitable dosage will be
obtained.
[0083] It is especially advantageous to formulate parenteral compositions in dosage unit
form for ease of administration and uniformity of dosage. Dosage unit form as used
herein refers to physically discrete units suited as unitary dosages for the subjects
to be treated; each unit containing a predetermined quantity of therapeutic compound
calculated to produce the desired therapeutic effect in association with the required
pharmaceutical carrier. The specification for the dosage unit forms of the invention
are dictated by and directly dependent on (a) the unique characteristics of the therapeutic
compound and the particular therapeutic effect to be achieved, and (b) the limitations
inherent in the art of compounding such a therapeutic compound for the treatment of
a selected condition in a patient.
[0084] The therapeutic compound may also be administered topically to the skin, eye, or
mucosa. Alternatively, if local delivery to the lungs is desired the therapeutic compound
may be administered by inhalation in a dry-powder or aerosol formulation.
[0085] The actual dosage amount of a compound of the present invention or composition comprising
a compound of the present invention administered to a subject may be determined by
physical and physiological factors such as age, sex, body weight, severity of condition,
the type of disease being treated, previous or concurrent therapeutic interventions,
idiopathy of the subject and on the route of administration. These factors may be
determined by a skilled artisan. The practitioner responsible for administration will
typically determine the concentration of active ingredient(s) in a composition and
appropriate dose(s) for the individual subject. The dosage may be adjusted by the
individual physician in the event of any complication.
[0086] In some embodiments, the pharmaceutically effective amount is a daily dose from about
0.1 mg to about 500 mg of the compound. In some variations, the daily dose is from
about 1 mg to about 300 mg of the compound. In some variations, the daily dose is
from about 10 mg to about 200 mg of the compound. In some variations, the daily dose
is about 25 mg of the compound. In other variations, the daily dose is about 75 mg
of the compound. In still other variations, the daily dose is about 150 mg of the
compound. In further variations, the daily dose is from about 0.1 mg to about 30 mg
of the compound. In some variations, the daily dose is from about 0.5 mg to about
20 mg of the compound. In some variations, the daily dose is from about 1 mg to about
15 mg of the compound. In some variations, the daily dose is from about 1 mg to about
10 mg of the compound. In some variations, the daily dose is from about 1 mg to about
5 mg of the compound.
[0087] In some embodiments, the pharmaceutically effective amount is a daily dose is 0.01
- 25 mg of compound per kg of body weight. In some variations, the daily dose is 0.05
- 20 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 10 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 5 mg of compound per kg of body weight. In some variations, the daily dose is 0.1
- 2.5 mg of compound per kg of body weight.
[0088] In some embodiments, the pharmaceutically effective amount is a daily dose is of
0.1 - 1000 mg of compound per kg of body weight. In some variations, the daily dose
is 0.15 - 20 mg of compound per kg of body weight. In some variations, the daily dose
is 0.20 - 10 mg of compound per kg of body weight. In some variations, the daily dose
is 0.40 - 3 mg of compound per kg of body weight. In some variations, the daily dose
is 0.50 - 9 mg of compound per kg of body weight. In some variations, the daily dose
is 0.60 - 8 mg of compound per kg of body weight. In some variations, the daily dose
is 0.70 - 7 mg of compound per kg of body weight. In some variations, the daily dose
is 0.80 - 6 mg of compound per kg of body weight. In some variations, the daily dose
is 0.90 - 5 mg of compound per kg of body weight. In some variations, the daily dose
is from about 1 mg to about 5 mg of compound per kg of body weight.
[0089] An effective amount typically will vary from about 0.001 mg/kg to about 1,000 mg/kg,
from about 0.01 mg/kg to about 750 mg/kg, from about 0.1 mg/kg to about 500 mg/kg,
from about 0.2 mg/kg to about 250 mg/kg, from about 0.3 mg/kg to about 150 mg/kg,
from about 0.3 mg/kg to about 100 mg/kg, from about 0.4 mg/kg to about 75 mg/kg, from
about 0.5 mg/kg to about 50 mg/kg, from about 0.6 mg/kg to about 30 mg/kg, from about
0.7 mg/kg to about 25 mg/kg, from about 0.8 mg/kg to about 15 mg/kg, from about 0.9
mg/kg to about 10 mg/kg, from about 1 mg/kg to about 5 mg/kg, from about 100 mg/kg
to about 500 mg/kg, from about 1.0 mg/kg to about 250 mg/kg, or from about 10.0 mg/kg
to about 150 mg/kg, in one or more dose administrations daily, for one or several
days (depending, of course, of the mode of administration and the factors discussed
above). Other suitable dose ranges include 1 mg to 10,000 mg per day, 100 mg to 10,000
mg per day, 500 mg to 10,000 mg per day, and 500 mg to 1,000 mg per day. In some particular
embodiments, the amount is less than 10,000 mg per day with a range, for example,
of 750 mg to 9,000 mg per day.
[0090] The effective amount may be less than 1 mg/kg/day, less than 500 mg/kg/day, less
than 250 mg/kg/day, less than 100 mg/kg/day, less than 50 mg/kg/day, less than 25
mg/kg/day, less than 10 mg/kg/day, or less than 5 mg/kg/day. It may alternatively
be in the range of 1 mg/kg/day to 200 mg/kg/day. For example, regarding treatment
of diabetic patients, the unit dosage may be an amount that reduces blood glucose
by at least 40% as compared to an untreated subject. In another embodiment, the unit
dosage is an amount that reduces blood glucose to a level that is within ± 10% of
the blood glucose level of a non-diabetic subject.
[0091] In other non-limiting examples, a dose may also comprise from about 1 microgram/kg/body
weight, about 5 microgram/kg/body weight, about 10 microgram/kg/body weight, about
50 microgram/kg/body weight, about 100 microgram/kg/body weight, about 200 microgram/kg/body
weight, about 350 microgram/kg/body weight, about 500 microgram/kg/body weight, about
1 milligram/kg/body weight, about 5 milligram/kg/body weight, about 10 milligram/kg/body
weight, about 50 milligram/kg/body weight, about 100 milligram/kg/body weight, about
200 milligram/kg/body weight, about 350 milligram/kg/body weight, about 500 milligram/kg/body
weight, to about 1000 mg/kg/body weight or more per administration, and any range
derivable therein. In non-limiting examples of a derivable range from the numbers
listed herein, a range of about 1 mg/kg/body weight to about 5 mg/kg/body weight,
a range of about 5 mg/kg/body weight to about 100 mg/kg/body weight, about 5 microgram/kg/body
weight to about 500 milligram/kg/body weight,
etc., can be administered, based on the numbers described above.
[0092] In certain embodiments, a pharmaceutical composition of the present invention may
comprise, for example, at least about 0.1% of a compound of the present invention.
In other embodiments, the compound of the present invention may comprise between about
2% to about 75% of the weight of the unit, or between about 25% to about 60%, for
example, and any range derivable therein.
[0093] Single or multiple doses of the agents are contemplated. Desired time intervals for
delivery of multiple doses can be determined by one of ordinary skill in the art employing
no more than routine experimentation. As an example, subjects may be administered
two doses daily at approximately 12 hour intervals. In some embodiments, the agent
is administered once a day.
[0094] The agent(s) may be administered on a routine schedule. As used herein a routine
schedule refers to a predetermined designated period of time. The routine schedule
may encompass periods of time which are identical or which differ in length, as long
as the schedule is predetermined. For instance, the routine schedule may involve administration
twice a day, every day, every two days, every three days, every four days, every five
days, every six days, a weekly basis, a monthly basis or any set number of days or
weeks therebetween. Alternatively, the predetermined routine schedule may involve
administration on a twice daily basis for the first week, followed by a daily basis
for several months,
etc. In other embodiments, the invention provides that the agent(s) may taken orally and
that the timing of which is or is not dependent upon food intake. Thus, for example,
the agent can be taken every morning and/or every evening, regardless of when the
subject has eaten or will eat.
[0095] Non-limiting specific formulations include CDDO-Me polymer dispersions (see
U.S. Application No. 12/191,176, filed August 13, 2008). Some of the formulations reported therein exhibited higher bioavailability than
either the micronized Form A or nanocrystalline Form A formulations. Additionally,
the polymer dispersion based formulations demonstrated further surprising improvements
in oral bioavailability relative to the micronized Form B formulations. For example,
the methacrylic acid copolymer, Type C and HPMC-P formulations showed the greatest
bioavailability in the subject monkeys.
VIII. Combination Therapy
[0096] In addition to being used as a monotherapy, the compound may also find use in combination
therapies. Effective combination therapy may be achieved with a single composition
or pharmacological formulation that includes both agents, or with two distinct compositions
or formulations, administered at the same time, wherein one composition includes a
compound for use according to the present invention, and the other includes the second
agent(s). Alternatively, the therapy may precede or follow the other agent treatment
by intervals ranging from minutes to months.
[0097] Various combinations may be employed, such as when a compound of the present invention
is "A" and "B" represents a secondary agent, non-limiting examples of which are described
below:

[0098] It is contemplated that other anti-inflammatory agents may be used in conjunction
with the treatments of the current invention. For example, other COX inhibitors may
be used, including arylcarboxylic acids (salicylic acid, acetylsalicylic acid, diflunisal,
choline magnesium trisalicylate, salicylate, benorylate, flufenamic acid, mefenamic
acid, meclofenamic acid and triflumic acid), arylalkanoic acids (diclofenac, fenclofenac,
alclofenac, fentiazac, ibuprofen, flurbiprofen, ketoprofen, naproxen, fenoprofen,
fenbufen, suprofen, indoprofen, tiaprofenic acid, benoxaprofen, pirprofen, tolmetin,
zomepirac, clopinac, indomethacin and sulindac) and enolic acids (phenylbutazone,
oxyphenbutazone, azapropazone, feprazone, piroxicam, and isoxicam. See also
U.S. Patent 6,025,395.
[0099] Dietary and nutritional supplements with reported benefits for treatment or prevention
of Parkinson's, Alzheimer's, multiple sclerosis, amyotrophic lateral sclerosis, rheumatoid
arthritis, inflammatory bowel disease, and all other diseases whose pathogenesis is
believed to involve excessive production of either nitric oxide (NO) or prostaglandins,
such as acetyl-L-carnitine, octacosanol, evening primrose oil, vitamin B6, tyrosine,
phenylalanine, vitamin C, L-dopa, or a combination of several antioxidants may be
used in conjunction with the compounds of the current invention.
[0100] Other particular secondary therapies include immunosuppressants (for transplants
and autoimmune-related RKD), anti-hypertensive drugs (for high blood pressure-related
RKD,
e.g., angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), insulin
(for diabetic RKD), lipid/cholesterol-lowering agents (
e.g., HMG-CoA reductase inhibitors such as atorvastatin or simvastatin), treatments for
hyperphosphatemia or hyperparathyroidism associated with CKD (
e.g., sevelamer acetate, cinacalcet), dialysis, and dietary restrictions (
e.g., protein, salt, fluid, postassium, phosphorus).
IX. Examples
[0101] The following examples are included to demonstrate preferred embodiments of the invention.
Example 1 - Materials and Methods
[0102] Chemicals. Triterpenoids were synthesized as previously described in Honda
et al. (1998), Honda
et al. (2000b), Honda
et al. (2002) and Yates
et al. (2007).
Example 2 - Mouse Ischemia-Reperfusion Results
[0103] In a mouse model of ischemic acute renal failure, the renal artery is clamped for
approximately twenty minutes. After this time, the clamp is removed and the kidney
is reperfused with blood. Ischemia-reperfusion results in renal damage and decreased
renal function which can be assessed by blood urea nitrogen (BUN) levels, which become
elevated following renal damage. As shown in FIGS. 1a-d, surgically-induced ischemia-reperfusion
increased BUN levels by approximately 2-fold. However, in animals treated with 2 mg/kg
RTA 402 orally once daily beginning two days prior to the surgery, the BUN levels
were significantly reduced (p<0.01) relative to vehicle-treated animals and were similar
to the levels in animals that underwent sham surgeries (FIGS. 1a-c). Histological
measures of kidney damage and inflammation were also significantly improved by treatment
with RTA 402 (FIG. 1d). These data indicate that RTA 402 is protective against ischemia-reperfusion
induced tissue damage.
Example 3 - Rat Chemotherapy-Induced Acute Renal Injury Results
[0104] In another model of acute renal injury, rats were injected intravenously with the
antineoplastic agent cisplatin. In humans, nephrotoxicity is a dose-limiting side
effect of treatment with cisplatin. Cisplatin-induced damage to the proximal tubules
is thought to be mediated by increased inflammation, oxidative stress, and apoptosis
(Yao
et al., 2007). Rats treated with a single dose of cisplatin at 6 mg/kg developed renal insufficiency
as measured by increased blood levels of creatinine and BUN. Treatment with 10 mg/kg
RTA 402 by oral gavage beginning one day prior to treatment with cisplatin and continuing
every day significantly reduced blood levels of creatinine and BUN (FIGS. 2a-b). Histological
evaluation of the kidneys demonstrated an improvement in the extent of proximal tubule
damage in RTA 402-treated animals compared to vehicle-treated animals (FIG. 2c).
Example 4 - Reduction of Serum Creatinine Levels in Several Species
[0105] Serum creatinine has been measured in several animal species treated with RTA 402
in the course of toxicology studies. Significant reductions of serum creatinine levels
relative to baseline levels or levels in control animals have been observed in cynomolgus
monkeys, beagle dogs, and Sprague-Dawley rats (FIGS. 3a-d). This effect has been observed
in rats with crystalline and amorphous forms of RTA 402.
Example 5 - Reduced Serum Creatinine and Increased eGFR in Cancer Patients
[0106] Serum creatinine has also been measured in patients with cancer enrolled in a Phase
I clinical trial of RTA 402. These patients received RTA 402 once daily at doses from
5 to 1,300 mg/day for a total of twenty-one days every 28 days. A reduction in serum
creatinine by greater than 15% was observed as early as eight days following treatment
initiation and persisted through the end of the cycle (FIG. 4A). This reduction was
maintained in those patients that received six or more cycles of treatment with RTA
402. A subset of patients with pre-existing renal damage (baseline serum creatinine
levels of at least 1.5 mg/dl) also had significant reductions in serum creatinine
levels following treatment with RTA 402. In these patients, serum creatinine levels
decreased progressively throughout the cycle such that the Day 21 levels were approximately
25% lower than baseline levels (FIG. 4A). These results can be summarized as shown
in the table below.
| |
All patients |
Sub-set with elevated baseline serum creatinine levels |
| Number of patients who received drug for at least 3 weeks |
45 |
8 |
| % of Patients with Decrease on Day 21 |
87% |
100% |
| % Serum Creatinine Decrease from Baseline |
-18.3% |
-24.5% |
| p-value (Baseline versus Day 21) |
0.001 |
0.0007 |
[0107] The estimated glomerular filtration rate (eGFR) significantly improved in the patients
treated with RTA 402 (FIG. 4B).
[0108] FIG. 5 shows the results following at least six months of RTA 402 treatment in eleven
cancer patients, showing that eGFR improved in an approximately continuous manner.
Some of these patients were enrolled in the Phase I study, whereas others were enrolled
in a study of RTA 402 (in combination with gemcitabine) in patients with pancreatic
cancer. The results can be summarized as shown in Table 2, below.
Table 2: eGFR in Patients Receiving RTA 402 for 6 Cycles.
| |
|
Solid Tumor Study |
Pancreatic Study |
| |
Pt ID: |
402 |
406 |
408 |
409 |
410 |
421 |
427 |
1001 |
1104 |
1105 |
1106 |
| |
Dose (mg): |
5 |
80 |
150 |
150/300 |
300/600 |
1300/900 |
1300 |
150 |
300/150 |
300 |
300 |
| |
BL |
109.7 |
94.2 |
73.2 |
48.4 |
49.9 |
52.5 |
70.1 |
68.8 |
67.3 |
82.4 |
89.0 |
| |
1 |
109.7 |
125.9 |
82.1 |
62.6 |
69.6 |
58.6 |
101.3 |
78.9 |
95.7 |
106.6 |
106.3 |
| Cycle |
2 |
109.7 |
107.9 |
77.4 |
62.6 |
63.4 |
66.2 |
78.3 |
109.9 |
71.6 |
89.3 |
106.3 |
| (each cycle is 28 days) |
3 |
95.7 |
107.9 |
69.4 |
62.6 |
63.4 |
75.8 |
88.4 |
135.7 |
141.2 |
106.6 |
106.3 |
| 4 |
95.7 |
125.9 |
77.4 |
57.0 |
69.6 |
N/A |
101.3 |
175.5 |
95.7 |
106.6 |
131.2 |
| |
5 |
109.7 |
107.9 |
77.4 |
69.2 |
63.4 |
88.4 |
101.3 |
175.5 |
114.4 |
131.6 |
131.2 |
| |
6 |
95.7 |
125.9 |
87.4 |
69.2 |
69.6 |
75.8 |
101.3 |
135.7 |
114.4 |
170.3 |
131.2 |
Example 6 - Phase 2 Study in Patients with Diabetic Nephropathy
[0109] Serum creatinine has also been measured in patients with chronic kidney disease (CKD)
enrolled in an open label Phase II clinical trial of RTA 402. These patients received
RTA 402 once daily at three dose levels, 25 mg, 75 mg and 150 mg, for a total of 28
days.
[0110] The study was designed with multiple endpoints, in categories of insulin resistance,
endothelial dysfunction/CVD, and CKD. These can be summarized as follows:
| Insulin Resistance/ Diabetes |
Endothelial Dysfunction/ Cardiovascular |
Chronic Kidney Disease |
| Hgb A1c |
CECs |
GFR |
| GDR/Euglycemic Clamp |
C-Reactive Protein (CRP) |
Serum Creatinine |
| Glucose |
E-Selectin |
Creatinine Clearance |
| |
VCAM |
Cystatin C |
| |
Cytokines |
Adiponectin |
| |
|
Angiotensin II |
[0111] A primary outcome measure for this study is determining the effects of RTA 402 administered
orally at the three dose strengths on the glomerular filtration rate (as estimated
by the MDRD formula) in patients with diabetic nephropathy.
[0112] Secondary outcome measures include: (1) an evaluation of the safety and tolerability
of oral RTA 402 administered orally at the three different doses, in this patient
population; (2) an evaluation of the effects of RTA 402 administered orally at the
three dose strengths on the serum creatinine level, creatinine clearance, and urine
albumin/creatinine ratio in patients with diabetic nephropathy; (3) an evaluation
of the effects of RTA 402 administered orally at the three dose strengths on hemoglobin
A1c in all patients enrolled and on insulin response by the hyperinsulinemic euglycemic
clamp test in patients enrolled at only one of the study centers; (4) an evaluation
of the effects of RTA 402 at the three different doses on a panel of markers of inflammation,
renal injury, oxidative stress, and endothelial cell dysfunction.
[0113] The patient population selected for this study all had type 2 diabetes with CKD.
Most had been diagnosed with poor glycemic control for two decades. CKD was established
through elevated serum creatinine (SCr) levels. Most of the patients had been diagnosed
with cardiovascular disease (CVD) and most were receiving standard of care (SOC) treatment
for diabetes, CKD and CVD, (
e.g., insulin, ACEI/ARB, β-blocker, diuretic, and statin). The baseline demographic can
be summarized as follows:
| Age |
59 |
| Diabetes Duration (yrs) |
15.4 |
| Diabetic Nephropathy |
100% |
| Non-renal Diabetic Complications1 |
100% |
| Hypertensive |
100% |
| Hgb A1c(%) |
7.9% |
| Failed Oral Antihyperglycemics |
90% |
| ACEI/ARB Use |
80% |
| Statin Use |
50% |
1Includes neuropathy and retinopathy
All values represent the mean; n = 10; 1st 10 patients to complete study |
[0114] The patient inclusion criteria were as follows: (1) diagnosis of type 2 diabetes;
(2) serum creatinine in women 1.3 - 3.0 mg/dL (115-265 µmol/L), inclusive, and in
men 1.5 - 3.0 mg/dL (133-265 µmol/L), inclusive; (3) patient must agree to practice
effective contraception; (4) patient must have a negative urine pregnancy test within
72 hours prior to the first dose of study medication; (5) patient is willing and able
to cooperate with all aspects of the protocol and is able to communicate effectively;
(6) patient is willing and able to provide written informed consent to participate
in this clinical study.
[0115] The patient exclusion criteria were the following: (1) patients having type 1 (insulin-dependent;
juvenile onset) diabetes; (2) patients with known non-diabetic renal disease (nephrosclerosis
superimposed on diabetic nephropathy acceptable), or with renal allograft; (3) patients
having cardiovascular disease as follows: unstable angina pectoris within 3 months
of study entry; myocardial infarction, coronary artery bypass graft surgery, or percutaneous
transluminal coronary angioplasty/stent within 3 months of study entry; transient
ischemic attack within 3 months of study entry; cerebrovascular accident within 3
months of study entry; obstructive valvular heart disease or hypertrophic cardiomyopathy;
second or third degree atrioventricular block not successfully treated with a pacemaker;
(4) patients with need for chronic (> 2 weeks) immunosuppressive therapy, including
corticosteroids (excluding inhaled or nasal steroids) within 3 months of study entry;
(5) patients with evidence of hepatic dysfunction including total bilirubin > 1.5
mg/dL (> 26 micromole/L) or liver transaminase (aspartate aminotransferase [AST] or
alanine transferase [ALT]) > 1.5 times upper limit of normal; (6) if female, patient
is pregnant, nursing or planning a pregnancy; (7) patients with any concurrent clinical
conditions that in the judgment of the investigator could either potentially pose
a health risk to the patient while involved in the study or could potentially influence
the study outcome; (8) patients having known hypersensitivity to any component of
the study drug; (9) patients having known allergy to iodine; (10) patients having
undergone diagnostic or intervention procedure requiring a contrast agent within the
last 30 days prior to entry into the study; (11) patients with change or dose-adjustment
in any of the following medications: ACE inhibitors, angiotensin II blockers, non-steroidal
anti inflammatory drugs (NSAIDs), or COX-2 inhibitors within 3 months; other anti-hypertensive,
and other anti-diabetic medications within 6 weeks prior to entry into the study;
(12) patients having a history of drug or alcohol abuse or having positive test results
for any drug of abuse (positive urine drug test and/or alcohol breathalyzer test);
(13) patients having participated in another clinical study involving investigational
or marketed products within 30 days prior to entry into the study or would concomitantly
participate in such a study; (14) patients unable to communicate or cooperate with
the Investigator due to language problems, poor mental development or impaired cerebral
function.
[0116] As of the end of September 2008, there were 32 of 60 patients enrolled in this study.
All but one patient was receiving insulin and standard-of-care oral antihyperglycemics.
[0117] Treatment with RTA 402 was observed to reduce hemoglobin % A1c in 28 days in refractory
diabetics on top of standard of care. The treatment showed an intent-to-treat reduction
of approximately 0.25 (n = 56) and an elevated baseline (≥ 7.0 at baseline) reduction
of 0.50 (n = 35). Hemoglobin % A1c reduction as a function of baseline severity is
shown in FIG. 6, and reduction as a function of dosage is shown in FIG. 7. Patients
with advanced (Stage 4) renal disease (GFR from 15-29 ml/min) showed a mean % A1c
reduction of approximately 0.77. All reductions were statistically significant.
[0118] Hyperinsulinemic euglycemic clamp test results showed that the 28 day treatment also
improved glycemic control and insulin sensitivity in the patients, as measured by
glucose disposal rate (GDR). Patients exhibited improvements in GDR after the 28 day
treatment, with more severely impaired patients (GDR < 4) showing statistically significant
improvements (p ≤ 0.02). The hyperinsulinemic euglycemic clamp test was performed
at Baseline (Day -1) and at the end of the study on Day 28. The test measures the
rate of glucose infusion (GINF) necessary to compensate for an increased insulin level
without causing hypoglycemia; this value is used to derive the GDR.
[0119] In short, the hyperinsulinemic euglycemic clamp test takes about 2 hours. Through
a peripheral vein, insulin is infused at 10-120 mU per m
2 per minute. In order to compensate for the insulin infusion, glucose 20% is infused
to maintain blood sugar levels between 5 and 5.5 mmol/L. The rate of glucose infusion
is determined by checking the blood sugar levels every 5 to 10 minutes. The rate of
glucose infusion during the last 30 minutes of the test is used to determine insulin
sensitivity as determined by the glucose metabolism rate (M) in mg/kg/min.
[0120] The following protocol guidelines are in place for the hyperinsulinemic euglycemic
clamp test:
- 1) Subject to fast 8-10 hours prior to the clamp procedure.
- 2) The morning of the clamp measure vital signs and weight.
- 3) Start a retrograde line in one hand with 1¼", 18-20 gauge catheter for drawing
samples.
- 4) Prepare IV tubing with 2 three-way stop cocks and j-loop extension tubing. Spike
tubing to a liter bag of 0.9% NaCl to run at KVO (keep vein open, about 10 cc/hr)
until the start of the procedure.
- 5) Apply a heating pad covered in a pillow case with a pad separating the heating
pad from the subject's hand. (Enables the collection of shunted arterialized blood
from venous catheterization)
- 6) Monitor the temperature (approximately 150 °F / 65 °C) generated by the heating
pad before and during the clamp, to maintain arterialization.
- 7) Start another line opposite the draw side in the distal forearm with 1¼", 18-20
gauge catheter for the infusion line. Prepare IV tubing with 2 three-way stop cocks.
- 8) Hang a 500 ml bag of 20% dextrose and attach to port on the infusion side
- 9) Prepare the insulin infusion
- a. Remove 53 cc (50 cc of overfill) of saline from a 500 cc bag of 0.9% NaCl and discard
- b. Draw 8 cc of blood from subject using sterile technique and inject into a tiger
top tube
- c. Centrifuge the tiger top tube. Withdraw 2 cc of serum and inject into the 500 cc
bag of 0.9% NaCl
- d. Add 100 units of insulin to the bag with the serum and mix well (0.2 U insulin/ml)
- e. Connect IV tubing with duo-vent spike into the 0.9% NaCl bag
- f. Place on Baxter pump
- 10) Time and draw all basal blood samples (Baseline fasting blood glucose values will
be obtained prior to beginning the insulin prime).
- 11) Perform insulin infusion rate calculations for a priming dose and 60 mU/m2 insulin infusion. This background insulin is to suppress endogenous hepatic glucose
production. Lean subjects can be suppressed with 40 mU/m2; obese, insulin resistant subjects require 80 mU/m2. 60 mU/m2 should be sufficient to suppress the suggested study population with a BMI of 27-40
kg/m2. The suggested 60 mU/m2 insulin infusion may need to be adjusted if the BMI is amended.
- 12) 0.5 mL samples will be drawn every five minutes and the readings from the YSI
Blood Glucose Analyzer will be used to determine/adjust the glucose infusion rate
(mg/kg/min). Any additional laboratory tests required by the protocol will be in addition
to the blood volume. The clamp will last 120 minutes which is believed to be a sufficient
duration for determining insulin sensitivity.
- 13) Label and save all YSI printouts for source documents.
- 14) The glucose infusion rates from the last 30 minutes of the euglycemic clamp will
be adjusted using space correction. This will be used to determine the glucose metabolism
rate (M mg/kg/min), which represents the subject's sensitivity to insulin.
[0121] As shown in FIG. 8, RTA 402 reduces circulating endothelial cells (CECs). The mean
number of CECs in cells/mL is shown for intent-to-treat (ITT) and elevated baseline
groups, both before and after the 28 day RTA treatment. The reduction for the Intent-to-treat
group was approximately 20%, and the reduction in the elevated baseline group (>5
CECs/ml) was approximately 33%. The fraction of iNOS-positive CECs was reduced approximately
29%. Normalization of CEC values (≤ 5 cells/mL) was observed in 11 out of the 19 patients
with elevated baseline.
[0122] CECs were isolated from whole blood by using CD146 Ab (an antibody to the CD146 antigen
that is expressed on endothelial cells and leukocytes). After CEC isolation, a FITC
(fluorescein isothiocyanate) conjugated CD105 Ab (a specific antibody for endothelial
cells) is used to identify CECs using the CellSearch™ system. A fluorescent conjugate
of CD45 Ab was added to stain the leukocytes, and these were then gated out. For a
general overview of this method, see Blann
et al., (2005). CEC samples were also assessed for the presence of iNOS by immunostaining.
Treatment with RTA 402 reduced iNOS-positive CECs by approximately 29%, further indicating
that RTA 402 reduces inflammation in endothelial cells.
[0123] RTA 402 was shown to improve significantly eight measures of renal function and status,
including serum creatinine based eGFR (FIG. 9), creatinine clearance, BUN (FIG. 11A),
serum phosphorus (FIG. 11B), serum uric acid (FIG. 11C), Cystatin C, Adiponectin (FIG.
10A), and Angiotensin II (FIG. 10B). Adiponectin predicts all-cause mortality and
end stage renal disease in DN patients. Adiponectin and Angiotensin II, which are
elevated in DN patients, correlate with renal disease severity (FIGS. 10A-B). Effects
on BUN, phosphorus, and uric acid are shown in FIGS. 11A-C.
[0124] Patients treated with higher doses (75 or 150 mg) of RTA 402 showed modest elevations
(approximately 20 to 25%) in proteinuria. This is consistent with studies indicating
that better GFR performance correlates with increased proteinuria. For example, in
a long-term clinical study of more than 25,000 patients, treatment with ramipril (an
ACE inhibitor) slowed the rate of eGFR decline more effectively than either telmisartan
(an angiotensin receptor blocker) or the combination of ramipril and telmisartan (Mann
et al., 2008). Conversely, proteinuria increased more in the ramipril group than in the other
two groups. Major renal outcomes were also better with either drug alone than with
combination therapy, although proteinuria increased least in the combination therapy
group. Other studies have shown that drugs that reduce GFR, such as ACE-inhibitors,
also reduce proteinuria (Lozano
et al., 2001; Sengul
et al., 2006). Other studies have shown that drugs that acutely increase GFR, such as certain
calcium channel blockers, increase proteinuria up to 60% during short-term dosing
(Agodoa
et al., 2001; Viberti
et al., 2002).
X. References
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