Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
2002-07-25
2003-11-11
Aulakh, Charanjit S. (Department: 1625)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
C546S077000
Reexamination Certificate
active
06645974
ABSTRACT:
BACKGROUND OF THE INVENTION
Androgens play important roles in post-natal development that are most pronounced at adrenarche and pubarche. Androgen production promotes the musculoskeletal anabolism associated with the pubertal growth in both males and females. At puberty, ovarian and testicular androgens are responsible for pubertal hair, acne, and enhancement of libido. In males, exposure to 100-fold increased levels of endogenous androgens results in the gender dimorphism in bone mass, muscle mass (positive nitrogen balance), and upper body strength, and are required for normal sexual development (genitalia, spermatogenesis, prostate and seminal vesicle maturation). Delay in puberty decreases the peak bone mass achieved during adulthood. (Bhasin, S., et al., Eds. Pharmacology, Biology, and Clinical Applications of Androgens: Current Status and Future Prospects. Wiley-Liss, Inc.:New York, 1996). In women, natural menopause causes virtually complete loss of ovarian estrogen production and gradually reduces ovarian production of androgen by approximately 50%. The physiological consequences of reduced androgen production after menopause are evident in decreased energy and libido, and contribute significantly in many women to vasomotor symptoms. Decreased androgen output is also thought to contribute—along with declining pituitary growth hormone (GH) secretion and insulin derived growth factor 1 (IGF1) action—to age-dependent sarcopenia, negative nitrogen balance and loss of bone mass. (Vestergaard, et al., Effect of sex hormone replacement on the insulin-like growth factor system and bone mineral: a cross-sectional and longitudinal study in 595 perimenopausal women participating in the Danish Osteoporosis Prevention Study, J Clin Endocrinol Metab. 84:2286-90, 1999; and Bhasin, et al., Eds. Pharmacology, Biology, and Clinical Applications of Androgens: Current Status and Future Prospects, Wiley-Liss, Inc.:New York. 1996). Postmenopausal osteoporosis results mainly from estrogen deficiency. However, many women who received estrogen replacement therapy still lose bone with age and develop age—related osteoporotic fractures (albeit at a lower rate than those taking estrogens), indicating that both estrogens and androgens play important roles for bone health in both women and men. The simultaneous decreases in bone mass, muscle mass and muscle strength increase the risk of falls and especially of hip fractures in both men and women >65 years of age. In fact, one-third of all hip fractures occur in men.
The androgen receptor (AR) belongs to the nuclear receptor superfamily and controls transcription in a ligand dependent manner (Brinkman, et al., Mechanisms of androgen receptor activation and function, J. Ster. Biochem. Mol. Biol. 69, 307-313, 1999). Upon androgen binding, AR binds directly to specific DNA sequences present in the promoter region of androgen responsive genes, termed androgen response elements (AREs), to stimulate transcription. Using ARE-dependent transcription as a criterion, agents that bind to AR and stimulate ARE-dependent transcription can be classified as agonists, and those that bind to AR and suppress ARE-dependent transcription are classified as antagonists. A number of natural or synthetic androgen agonists have been used for treatment of musculoskeletal or hematopoietic disorders and for hormone replacement therapy. In addition, AR antagonists, such as flutamide or bicalutamide, are used for treatment of prostate cancer. However, clinical use of these androgen agonists or antagonists have been limited because of undesirable effects, such as hirsutism and prostate enlargement for agonists, and bone loss, fracture, gynecomastia and sarcopenia for antagonists. It would be useful to have available androgens with tissue selective agonistic activity, which increase bone formation and muscle mass but do not induce the virilization.
Osteoporosis is characterized by bone loss, resulting from an imbalance between bone resorption (destruction) and bone formation, which starts in the fourth decade continues throughout life at the rate of about 1-4% per year (Eastell, Treatment of postmenopausal osteoporosis, New Eng. J. Med. 338: 736, 1998). In the United States, there are currently about 20 million people with detectable fractures of the vertebrae due to osteoporosis. In addition, there are about 250,000 hip fractures per year due to osteoporosis, associated with a 12%-20% mortality rate within the first two years, while 30% of patients require nursing home care after the fracture and many never become fully ambulatory again. In postmenopausal women, estrogen deficiency leads to increased bone resorption resulting in bone loss in the vertebrae of around 5% per year, immediately following menopause. Thus, first line treatment/prevention of this condition is inhibition of bone resorption by bisphosphonates, estrogens, selective estrogen receptor modulators (SERMs) and calcitonin. However, inhibitors of bone resorption are not sufficient to restore bone mass for patients who have already lost a significant amount of bone. The increase in spinal BMD attained by bisphosphonate treatment can reach 11% after 7 years of treatment with alendronate. In addition, as the rate of bone turnover differs from site to site; higher in the trabecular bone of the vertebrae than in the cortex of the long bones, the bone resorption inhibitors are less effective in increasing hip BMD and preventing hip fracture. Therefore, osteoanabolic agents, which increase cortical/periosteal bone formation and bone mass of long bones, would address an unmet need in the treatment of osteoporosis especially for patients with high risk of hip fractures. The osteoanabolic agents also complement the bone resorption inhibitors that target the trabecular envelope, leading to a biomechanically favorable bone structure. (Schmidt, et al., Anabolic steroid: Steroid effects on bone in women, 1996, In: J. P. Bilezikian, et al., Ed. Principles of Bone Biology. San Diego: Academic Press.)
A number of studies provide the proof of principle that androgens are osteoanabolic in women and men. Anabolic steroids, such as nandrolone decanoate or stanozolol, have been shown to increase bone mass in postmenopausal women. Beneficial effects of androgens on bone in post-menopausal osteoporosis are well-documented in recent studies using combined testosterone and estrogen administration (Hofbauer, et al., Androgen effects on bone metabolism: recent progress and controversies, Eur. J. Endocrinol. 140, 271-286, 1999). Combined treatment increased significantly the rate and extent of the rise in BMD (lumbar and hip), relative to treatment with estrogen alone. Additionally, estrogen—progestin combinations that incorporate an androgenic progestin (norethindrone) rather than medroxyprogesterone acetate yielded greater improvements in hip BMD. These results have recently been confirmed in a larger (N=311) 2 year, double blind comparison study in which oral conjugated estrogen (CEE) and methyltestosterone combinations were demonstrated to be effective in promoting accrual of bone mass in the spine and hip, while conjugated estrogen therapy alone prevented bone loss (A two-year, double-blind comparison of estrogen-androgen and conjugated estrogens in surgically menopausal women: Effects on bone mineral density, symptoms and lipid profiles. J Reprod Med. 44(12):1012-20, 1999). Despite the beneficial effects of androgens in postmenopausal women, the use of androgens has been limited because of the undesirable virilizing and metabolic action of androgens. The data from Watts and colleagues demonstrate that hot flushes decrease in women treated with CEE+ methyltestosterone; however, 30% of these women suffered from significant increases in acne and facial hair, a complication of all current androgen pharmacotherapies (Watts, et al., Comparison of oral estrogens and estrogens plus androgen on bone mineral density, menopausal symptoms, and lipid-lipoprotein profiles in surgical menopause, Obstet. Gynecol. 85, 529-537, 1995). More
Breslin Michael J.
Duggan Mark E.
Halczenko Wasyl
Harada Shun-Ichi
Hutchinson John H.
Aulakh Charanjit S.
Fitch Catherine D.
Merck & Co. , Inc.
Shatynski Patricia A.
Winokur Melvin
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