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PubMed1999

[Results of international clinical trials with raloxifene].

A new drug class called Selective Estrogen Receptor Modulators (SERM) could combine ideal properties for a product designed for menopausal women. The most widely studied member of this class is raloxifene which is currently marketed in several countries for the prevention of osteoporosis in menopaused women. This product is a nonsteroidal derivative of benzothiophene which, like estrogens, has a preventive effect against bone loss involving the spine and peripheral skeleton and a cholesterol lowering effect, both in the ovariectomized rat and in menopausal women. Unlike estrogens, raloxifene does not stimulate breast or uterine tissue. These interesting properties make raloxifene a possible preventive treatment for osteoporosis and other menopause-related risks for menopausal women of all ages. Multicenter studies have been conducted in recently menopausal women who received either raloxifene at the doses of 30, 60, or 150 mg/day or a placebo in a randomized protocol. All subjects were also given calcium supplementation. Bone density was measured twice a year for 36 months by dual X-rays absorptiometry and showed a significant decrease at all sites in the placebo group while there was a significant increase in the spine, the hip and the overall skeleton for all three raloxifen groups. After 24 months of treatment, mean increase over placebo was 2.4% for 60 mg raloxifene measured on the spine and total hip and 2% for the overall skeleton. Markers of bone formation (serum osteocalcin and bone alkaline phasphatase) and resorption (urinary CrossLaps) decreased significantly reaching, after 3 to 6 months of treatment, the levels observed in non menopausal women. In addition, total serum cholesterol as well as LDL-cholesterol decreased significantly in a dose-dependent fashion in all groups treated with raloxifene. Serum HDL-cholesterol and triglycerides did not very significantly during treatment. Hot flashes were the most frequently observed undesirable effect, at a frequency slightly higher in the raloxifene group (25%) than in the placebo group (18%). This undesirable effect was of low intensity and generally occurred during the first months of treatment. It did not cause a higher drop out rate (raloxifen 1.5%; placebo 2.1%). The preliminary data at two years follow-up suggest that raloxifene is not associated with an increased risk of breast cancer. In conclusion, raloxifene is a particularly interesting drug for menopausal women showing very promising efficacy and clinical tolerance.

Animals↗
PubMed2006

Current pharmacological options for the management of primary hyperparathyroidism.

Drugs for treating primary hyperparathyroidism can be divided into two main groups: (i) antiresorptive drugs that inhibit the increased bone turnover, which can be divided into estrogen-like compounds (estrogen, oral contraceptives and selective estrogen receptor modulators [SERMs]), bisphosphonates and calcitonin; and (ii) drugs that interfere with parathyroid hormone (PTH) secretion (currently only cinacalcet is available). No drugs that interfere with PTH action are currently available. Available studies suggest that all classes of drugs are able to lower serum calcium levels. However, calcitonin does so only temporarily. Estrogen-containing compounds (hormone replacement therapy) may be less attractive because of the potential risk of breast cancer, cardiovascular disease and deep vein thromboembolism. Oral contraceptives have not been shown to be able to prevent fractures in the general population, and no data are available on their effect in women with primary hyperparathyroidism. The only SERM marketed for hyperparathyroidism is raloxifene and this has not been associated with an increased risk of breast cancer and cardiovascular diseases, and has been shown to be able to prevent vertebral fractures in postmenopausal women with osteoporosis. Two small trials suggest that raloxifene may increase bone mineral density (BMD) and decrease serum calcium levels in patients with primary hyperparathyroidism. Bisphosphonates have been shown to decrease serum calcium and increase BMD in patients with primary hyperparathyroidism, but PTH levels may increase. Cinacalcet effectively induces a sustained decrease in serum calcium and PTH for up to 1 year. However, BMD does not seem to increase. No data on hard endpoints such as fractures, kidney stones, cardiovascular disease etc. are available for any of the drugs available for the treatment of primary hyperparathyroidism.

Bone Density↗
PubMed2006

What role of estrogens in ovarian stimulation.

Estrogens and progesterone represent the key ovarian hormones produced by the developing ovulatory follicle. Serum concentrations start to rise from the mid-follicular phase onwards, coinciding with the development of the dominant follicle. Androgens are converted into estrogens by aromatase activity of the granulosa cells and secreted into the follicular fluid compartment. Their significance for oocyte maturation and fertilizing potential remains unknown. Paradoxically, serum estrogen levels are within the normal range in the majority of patients presenting with cycle abnormalities due to ovarian dysfunction. Similarly, the distribution of estradiol (E2) and follicle-stimulating hormone (FSH) levels within the normal range is comparable between normo-ovulatory controls and normogonadotropic anovulatory women. Moreover, E2 levels are only moderately correlated with luteïnizing hormone (LH), testosterone (T), androstenedione (A), sex hormone binding globulin (SHBG), the free androgen index (FAI) and finally ovarian volume as measured by ultrasound. No correlations could be found between E2 and age, body weight and cycle history and FSH. Androgen concentrations and cycle history--but not E2--were the most prominent predictors of ovarian response tot the conventional ovulation induction. Anti-estrogenic compounds like clomiphene citrate and tamoxifen have remained the first-line treatment of choice for anovulation. Certainly, CC and to a lesser extent tamoxifen have demonstrated to exhibit undesired anti-estrogenic properties at the uterine level however. However, large follow-up studies demonstrate cumulative ovulation rates around 75%, and the overall pregnancy rates of around 50%. Aromatase inhibitors, another way to interfere with estrogen feedback, represent a feasible option. This claim should, however, be substantiated by further sufficiently powered, controlled studies, and the possibility of embryo toxicity remains a major concern. In retrospect, CC and tamoxifen represent the first generation of selective estrogen receptor modulators (SERMs), and many new compounds have recently been introduced into the clinic or are currently under investigation. The major focuses of these compounds are bone density, the cardiovascular system and breast cancer. No studies have been reported in the area of ovarian stimulation.

Anovulation↗
PubMed1999

Pharmacotherapy of dyslipidemia in postmenopausal women: weighing the evidence.

In the United States, coronary heart disease (CHD) is the leading cause of death in women. The incidence of CHD rises dramatically in women following menopause, which can be partially attributed to a more atherogenic lipoprotein profile. For years, observational and epidemiological data have suggested that estrogen and progesterone therapy reduced CHD end points. However, the first prospective trial that evaluated hormone replacement therapy (HRT) for secondary CHD prevention demonstrated no positive cardiovascular benefit of HRT compared with placebo. In interventional studies, the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)reductase inhibitors significantly reduced CHD outcomes in postmenopausal women, and these agents have emerged as the drugs of choice for primary and secondary CHD prevention. The selective estrogen receptor modulators (SERMs) may have a role in CHD prevention, but long-term clinical trials evaluating end points are needed. An evidence-based approach is necessary when deciding the appropriate pharmacotherapy of dyslipidemia in postmenopausal women.

Aged↗
PubMed2006

Clinical review: The rationale for banning human chorionic gonadotropin and estrogen blockers in sport.

CONTEXT: The objective of the study was to review the rationale underlying the banning of human chorionic gonadotropin (hCG) and estrogen blockers (antiestrogens, specific estrogen receptor modulators, aromatase inhibitors) in sports for male and female athletes in the light of gender differences in regulation of reproductive physiology. EVIDENCE ACQUISITION: We reviewed well-controlled clinical studies of exogenous testosterone effects on human muscle size and strength in men and all available evidence relevant to the effects of hCG and estrogen blockers on blood testosterone in men and women. EVIDENCE SYNTHESIS: Well-designed placebo-controlled clinical studies in men with suppressed pituitary-testicular axis establish a strong case that, across a wide range from sub- to supraphysiological doses, muscle growth and strength is proportional to exogenous testosterone dose and resulting blood testosterone concentrations. In men, there is unequivocal evidence that hCG and estrogen blockers cause consistent and sustained rise in blood testosterone concentrations. In women, although there has been no direct testing of ergogenic or myotrophic properties of exogenous testosterone in healthy women, either hCG or estrogen blockers do not produce any consistent or biologically significant increase blood testosterone concentrations. CONCLUSIONS: In men undergoing potential stimulation of endogenous blood testosterone concentrations, blood testosterone concentration is a reasonable surrogate measure for muscle growth and increased strength in men. Because hCG and estrogen blockers produce marked increase in blood testosterone concentration in men, this provides strong evidence to support the banning of hCG and estrogen blockers in men. In women, however, the negligible effect on blood testosterone suggests that drug-induced performance enhancement by hCG or estrogen blockers is highly unlikely. Furthermore, routine urinary hCG testing in young women risks invasion of privacy by detecting unrecognized pregnancy. These considerations suggest that prohibition of hCG and estrogen blockers should be restricted to men in which they are well justified.

Chorionic Gonadotropin↗
PubMed2005

Lasofoxifene (Pfizer).

Pfizer is developing lasofoxifene, an oral naphthalene derivative selective estrogen receptor modulator identified under a collaboration with Ligand, for the treatment of osteoporosis and vaginal atrophy. In August 2004, Pfizer submitted a New Drug Application to the Food and Drug Administration (FDA) seeking approval of lasofoxifene for the treatment of osteoporosis; however, in September 2005, the FDA issued a non-approvable letter.

Animals↗
PubMed2006

Selective modulators of PPAR activity as new therapeutic tools in metabolic diseases.

Peroxisome Proliferator Activated Receptors (PPARs) are regulators of metabolic pathways mainly of lipid metabolism and energy balance. Their medical importance is given by the fact that they have been implicated in development of insulin resistance, obesity and atherosclerosis. In recent years, major progress has been made in understanding the molecular basis of the function of these receptors. As a result of structural studies and identification of putative natural as well as synthetic ligands and activators of PPARs a new concept emerged and new drugs are on their ways to the clinic. The concept of Selective PPAR Modulators (SPPARM) was suggested by analogy to Selective Estrogen Receptor Modulators (SERM). SPPARMs activate the receptors in distinct ways leading to differential gene expression and biological response. The key features in understanding their action is most likely at the molecular details of ligand binding and the subsequently induced conformational changes as well as cofactor binding. A key aspect of this is that unlike classical steroid hormone receptors such as the retinoic acid receptor, the PPAR receptors have a rather large ligand-binding pocket which is not filled with the ligand entirely and the ligand also stabilizes the receptor's structure. The liganded receptor can have distinct conformations and this leads to different binding affinities for the various cofactors (coactivators and corepressors). In this review, we will introduce this concept, review the literature that supports it and present an overview of the receptor selective ligands including data about their mechanism of action and biological effects.

Animals↗
PubMed2002

Effect of 1 year of discontinuation of raloxifene or estrogen therapy on bone mineral density after 5 years of treatment in healthy postmenopausal women.

The beneficial effects of hormone replacement therapy (HRT), selective estrogen receptor modulators (SERMs), or bisphosphonates in the prevention and treatment of osteoporosis in postmenopausal women have been well established. However, little is known about the effects of discontinuation of treatment on bone mineral density. We investigated the effect of 1 year of discontinuation of the SERM raloxifene (Ral; 60 mg and 150 mg), conjugated equine estrogen (CEE; 0.625 mg), and placebo after 5 years of treatment in a double-blind, randomized study. Thirty-eight of 59 healthy and hysterectomized postmenopausal women (mean age 55 years) completed the treatment and 1 year follow-up period. Lumbar spine and femoral neck bone mineral density (BMD) were performed with dual-energy X-ray absorptiometry, before, during, and at the end of treatment, as well as after 1 year of discontinuation of therapy. One year of discontinuation significantly reduced the mean lumbar spine BMD in the raloxifene- and estrogen-treated women (p < 0.05), whereas mean femoral neck BMD was reduced significantly only in women treated with 60 mg Ral (p < 0.05). The mean percentage change (+/-SD) in lumbar spine BMD was: CEE, -6.2% (+/-3.7%); Ral 60 mg, -2.4% (+/-2.4%); Ral 150 mg, -2.6% (+/-3.1%); and placebo, -1.6% (+/-4.3%). Our results show that 5 years of treatment with either Ral or CEE did not protect against bone loss after 1 year of withdrawal of therapy, and that the rate of bone loss was not significantly different from that of placebo-treated women.

Bone Density↗
PubMed2001

In vitro and in vivo biologic effects of Ospemifene (FC-1271a) in breast cancer.

Ospemifene (FC-1271a) is a novel selective estrogen receptor modulator under development for osteoporosis prevention. In the present paper, we examine both the in vitro and in vivo effects of FC-1271a in breast cancer models. In vitro, the growth inhibitory effects of FC-1271a and its main metabolite are investigated in MCF-7 and MDA-MB-231 human breast cancer cells at doses ranging from 0.1 to 10 microM. Modulation of pS2 expression, an indicator of estrogen activity, was also examined in all experiments using reverse transcription-polymerase chain reaction. In vivo, the effects of treatment with 10, 25, 50, or 100 mg/kg FC-1271a on MCF-7 and MDA-MB-231 human tumor xenografts in athymic, ovariectomized mice were determined. For MCF-7 cells, FC-1271a and its main metabolite, toremifene VI (TOR VI) displayed anti-estrogenic effects in vitro as shown through growth inhibition and decreased expression of pS2. Treatment with FC-1271a in vivo inhibited MCF-7 tumor growth, compared with control (P< or =0.05). FC-1271a and TOR VI did not inhibit the growth of MDA-MB-231 cells in vitro, and no clear effects of FC-1271a treatment were seen on MDA-MB-231 tumor growth in vivo. In conclusion, FC-1271a appears to exert anti-estrogenic effects dependent on estrogen receptor positivity in vitro and in vivo on the growth of MCF-7 cells.

Animals↗
PubMed2000

Raloxifene: a new choice for treating and preventing osteoporosis.

Selective estrogen receptor modulators (SERMs) are a new class of drugs that provide a new option for addressing the health challenges of postmenopausal women. This review discusses the proposed mechanism of action of SERMs and describes clinical findings on raloxifene, a SERM now available for treating and preventing osteoporosis.

Aged↗
PubMed2003

Raloxifene analog LY117018 enhances the regeneration of sciatic nerve in ovariectomized female mice.

The aim of this study was to examine the effects of LY117018, a selective estrogen receptor modulator, on peripheral nerve regeneration, using a model of sciatic nerve crush injury in mice. Sciatic functional index, an index of functional recovery, was significantly higher in LY117018 treated mice throughout regeneration. Analysis of semi-thin sections revealed a significant increase in both the total number of regenerating nerve fibers at day 7, and the mean axonal area of myelinated fibers at 7, 14, and 21 days after injury, in LY117018 treated mice. Analysis of axonal transport through retrograde labeling of motor neurons showed that LY117018 increased transport, and ICI 182,780 blocked the effects of LY117018, delineating estrogen receptors as its target. Our study suggests that LY117018 may markedly accelerate peripheral nerve regeneration and functional recovery through activation of estrogen receptors.

Animals↗
PubMed2005

Repercussions of raloxifen, tamoxifen and estrogen on aortic atherosclerotic lesions of female rabbits submitted to ovariectomy and hypercholesterol diet.

BACKGROUND: The role of hormone-replacement therapy in decreasing the risk of cardiovascular disease in women has not been firmly established. Recent studies have shown that the selective estrogen receptor modulators raloxifene, and tamoxifene, posses hypolipidemic and antiatherogenic properties. METHODS AND RESULTS: Forty-three adult female rabbits were submitted to ovariectomy (moment 1). Three weeks after surgical recovery, they were grouped in five groups as follows (moment 2): control group (9)--normal diet; cholesterol group (8)--0.5% cholesterol added to diet; raloxifen group (8); tamoxifen group (9); estrogen group (9)--diet added by 0.5% cholesterol and 60 mg raloxifen, 20 mg tamoxifen or 0.625 mg equine conjugated estrogen. The animals from all groups were sacrificed after 13 weeks (moment 3) and the thoracic and abdominal aortas were studied. We collected digital images of the observed atherosclerotic lesions in the vessel lumen by means of a computerized method. We analyzed serum levels of total cholesterol and fractions (HDL, VLDL, and LDL), as well as triglycerides. Among the animals that received hyper cholesterol diet and medication, we noticed a reduction of the total area of atherosclerotic plaques in the tamoxifen (P < 0.05) or estrogen group (P < 0.05) compared to the cholesterol group. Serum levels of total, LDL- and HDL-cholesterol were higher for the raloxifen, tamoxifen, estrogen, and cholesterol (P = 0.0001). CONCLUSION: Female rabbits treated with a high cholesterol diet associated to tamoxifen or estrogen had a statistically significant reduction in aortic atherosclerotic plaques. Even though there was a significant increase in cholesterol levels, we did not find any correlation between cholesterol levels and degree of aortic atherosclerotic lesion.

Animals↗
PubMed2006

Effect of ormeloxifene on ovariectomy-induced bone resorption, osteoclast differentiation and apoptosis and TGF beta-3 expression.

Effect of ormeloxifene, a multifunctional selective estrogen receptor modulator, on prevention of ovariectomy-induced bone resorption in retired breeder female rats, osteoclastogenesis using bone marrow cells from adult Balb/c mice cultured in presence of M-CSF and RANKL, osteoclast apoptosis using terminal deoxynucleotidyl transferase fragment end labeling and TGF beta-3 expression were investigated. Raloxifene, a benzothiophene reported to mimic effects of estrogen in bone, and estradiol were used for comparison. Ormeloxifene (10(-6) and 10(-8)M) significantly inhibited osteoclastogenesis (P<0.001 versus vehicle control) as evidenced by lower number of TRAP-positive osteoclasts in bone marrow cultures and caused apoptosis of osteoclasts. The effect was almost equivalent to that observed in presence of estradiol-17 beta, except that significant number of cells undergoing apoptosis was evident even at 10(-9)M concentration of estradiol-17 beta (P<0.001). Raloxifene, though inhibited osteoclastogenesis at much lower concentrations (10(-8) to 10(-12)M; P<0.001), failed to cause apoptosis of osteoclasts at any of the concentrations used. While ormeloxifene, raloxifene and ethynylestradiol significantly prevented ovariectomy-induced bone loss in vivo in retired breeder female rats, prevention of ovariectomy-induced decrease in BMD and trabecular network of proximal tibia, calcium and phosphorus levels in femur and tibia and prevention of ovariectomy-induced down-regulation of TGF beta-3 expression in lumbar vertebrae was of lower order in raloxifene- than ormeloxifene- or ethynylestradiol-supplemented females. Both the SERMs, however, produced considerable estrogenic effects at the uterine level as evidenced by increase in weight, total and endometrial area and luminal epithelial cell height; the effect being generally greater in raloxifene- than ormeloxifene-treated rats. Findings demonstrate that inhibition of estrogen-deficiency osteoporosis by ormeloxifene, as in case of estradiol, was mediated via inhibition of osteoclastogenesis, apoptosis of osteoclasts and up-regulation of TGF beta-3 expression. Raloxifene, though effective in inhibiting osteoclastogenesis in vitro at much lower concentrations, was not only less potent in preventing ovariectomy-induced bone loss in retired breeder female rats in vivo but also appeared to have a different mechanism of action than ormeloxifene and estradiol.

Animals↗
PubMed2006

[SERMs for treatment of osteoporosis: state-of-the-art and perspectives].

Every year in France, we observe 60,000 vertebral fractures, 50,000 hip fractures and 35,000 wrist fractures. However, only 20% of these patients receive adequate pharmacologic therapy to prevent new fractures and their complications. At the present time, clinicians have not a perfect knowledge of the therapeutic class of SERMs (Selective Estrogen Receptor Modulators). In this paper, the authors show the strong capacity of these drugs to produce, in osteoporotic postmenopausal women, major therapeutic effects on bone (reduction of fracture risk), on breast (reduction of cancer risk), and without any side effects on arterial diseases except an increased risk of venous thromboembolism.

Breast Neoplasms↗
PubMed1999

Activation of transcription by estrogen receptor alpha and beta is cell type- and promoter-dependent.

Tamoxifen acts as a strong estrogen antagonist in human breast but as an estrogen agonist in the uterus. The action of tamoxifen is mediated through estrogen receptors (ERalpha and ERbeta), which bind to a variety of responsive elements, to activate transcription. To examine the role of these varied elements in the response to antiestrogens, we studied the activation of a panel of differing promoters, by these compounds, in human breast, bone, and endometrial derived cell lines. No agonistic activity was observed in breast cells, whereas all antiestrogens, particularly tamoxifen, exhibited agonistic effects in uterine cell lines. All antiestrogens studied were agonistic in co-transfections of a collagenase reporter gene and ERbeta, but tamoxifen alone was agonistic with ERalpha in (uterine) HEC-1-A cells. The ERalpha mediated, agonism of tamoxifen was not observed in primary cultures of human uterine stromal cells, whereas the ERbeta-mediated agonism of all selective estrogen receptor modulators was present. This suggests that the two receptors operate by distinct pathways and that the response of cells to antiestrogens is dependent on the ER subtypes expressed.

Blotting, Western↗
PubMed2004

The safety of black cohosh (Actaea racemosa, Cimicifuga racemosa).

Black cohosh (Actaea racemosa/Cimicifuga racemosa) is a North American perennial plant that has been used for traditional medicinal purposes by the native Indian population. Its modern day application is the treatment of menopausal symptoms. Unlike conventional non-herbal medications, herbal preparations have not been systematically evaluated for their safety. However, the evidence from in vitro, animal and clinical studies all suggest that black cohosh is a safe herbal therapy for menopausal women if taken for a limited period. More research is needed to evaluate the safety of this herb over longer periods of time, and also to further investigate its mechanism of action.

Adverse Drug Reaction Reporting Systems↗
PubMed2005

[Treatment of bone mass loss in postmenopausal women].

In this revision, the results of different controlled clinical trials and metaanalyses on the efficacy in the increase of bone mineral density (BMD) and reduction of risk of fracture on postmenopausal osteoporosis treatments are summarized. Most of the drugs studied produce significant BMD increases but with significant differences regarding fracture risk reduction, especially regarding extravertebral fractures. Bisphosphonates and selective estrogen receptor modulators would constitute the first line of treatment of postmenopausal osteoporosis with previous fractures. Head to head studies would be necessary to know its true efficacy since some results are based on post hoc analysis. Possible side effects, risks, treatment comfort and price in addition to the demonstrated efficacy in fracture prevention must be considered in the selection of treatment.

Diphosphonates↗
PubMed2007

Two unsuccessful clinical trials on endometriosis and a few lessons learned.

In 1999, a phase II clinical trial on the use of fulvestrant to treat endometriosis was launched; yet after 7 years there is still no report on its outcome. In 2005, another trial on the use of raloxifene to treat endometriosis was terminated early due to unfavorable outcome. The two apparently unsuccessful clinical trials on endometriosis have taught us a few important lessons. First, we need to understand endometriosis through more basic research. We have also been reminded that human endometriosis trials differ from animal studies; anatomy and physiology are often divergent, and outcome measures are certainly different. Ectopic endometrium can differ significantly from eutopic tissue, and this issue needs to be more thoroughly explored. We believe human cell lines will prove to be an inexpensive and valuable tool for future preliminary evaluation of medical therapies as well as discerning pathophysiologic processes of the disease. Based on our current understanding of endometriosis, some concrete benchmarks can be established for testing or screening potential compounds in vitro. Finally, estrogen receptor modulators are often tissue-, cell-, and context-specific in their actions; they should not be simplistically grouped together nor should extrapolations from one compound to another be undertaken in a cavalier manner.

Adult↗