Alendronic acid in primary prevention: new indication. No reduction in fracture risk

(1) Alendronic acid at a dose of 5 mg/day is now licensed in France for primary prevention of postmenopausal fractures. (2) The clinical file is relatively bulky and methodologically adequate, but there are no comparisons with combined hormone replacement therapy or with raloxifen. (3) Three trials have shown that 5 mg/day alendronic acid slows postmenopausal bone loss. However, this effect disappears on treatment cessation, and mineral bone density is only one risk factor for postmenopausal fractures. (4) A placebo-controlled trial of primary prevention involving more than 4,000 patients showed no reduction in the risk of fracture after 4 years of treatment with alendronic acid (5 mg/day for 2 years, then 10 mg/day). (5) Alendronic acid increases the risk of oesophageal ulceration, necessitating strict precautions during ingestion.

Antiresorption therapy and reduction in fracture susceptibility in the osteoporotic elderly patient: open study

The identification of risk factors for osteoporosis has been an essential step towards the understanding of the onset of the disease as well as of the osteoporosis-related fractures due to bone fragility. The present study has been aimed at assessing whether a correlation may exist between the increment in bone mass, consequent to an antiresorption therapy, and the reduction in the incidence of fractures. Moreover, the possibility that such a reduction might result from the action of other factors, such as the changes in bone microstructure, has been investigated. A total of 2,000 osteoporotic women (mean age: 68 +/- 9 years) were enrolled in the study and divided at random into 4 treatment groups. Each group received one of the following treatments: Alendronate 10 mg/daily (1,000 patients), Clodronate 100 mg/weekly i.m. (800 patients), Risedronate 5 mg/dailt (100 patients), and Raloxifene 60 mg/daily (100 patients). Clinical evaluation was based on bone mineral density (BMD) assay on lumbar vertebrae (L1-L4) by means of a DEXA (Lunar DPX) mineralometer, as well as on the incidence of fractures following both 12- and 24-month treatment periods. The results showed an overlapping pattern in patients treated with Alendronate or Risedronate, namely a significant increment in BMD after a 24-month treatment period, whereas such an increment in BMD was less evident in patients receiving either Clodronate or Risedronate after a 24-month treatment period. In addition, a total of 18 osteoporosis-related fractures were observed during the entire study period; 10 out of 18 fractures occurred in the Alendronate treated group, whereas the remaining 8 fractures were observed in the Clodronate treated group. Fourteen fractures were detected in patients over 80-year old, whereas the remaining 4 occurred in patients aged from 70 to 79 years and appeared to be independent of both the T-score assigned and the BMD increment obtained as a result of the therapy. Such findings suggest that the plain monitoring of BMD appears not to be adequate to anticipate clearly the danger of the probable onset of additional fractures, while the higher incidence of fractures in patients over 80-year old evidences that "old age" has to be considered the most serious risk factor for osteoporosis, since it is also the real responsible factor for changes taking place in bone microstructure.

Efficacy of combined medication of risedronate sodium and selective estrogen receptor modulator on the postmenopausal osteoporosis

To evaluate the efficacy of combined medication of risedronate sodium and raloxifene, a selective estrogen receptor modulator (SERM) on the postmenopausal osteoporosis (PMOP). PMOP patients underwent the combined medication of risedronate sodium and raloxifene (SERM, Treatment group), or only medication of risedronate sodium (Control group). After medication, more significant increases were observed in the bone densities of the lumber vertebra (L<inf>1-4</inf>) and the neck of left femur of patients in the treatment group. Simultaneously, the levels of estrogen and progesterone in serum decreased sharply in the treatment group. After treatment, P1NP and β-CTX levels in serum decreased significantly in two groups in comparison with the levels prior to treatment, with evident elevations in the levels of BAP and BGP; similarly, ameliorations in the treatment group were much more evident than those in the control group. In addition, significant declines were identified in the VAS scores of two groups after treatment when comparing to the scores prior to the treatment, and the decline in the treatment group was more evident than that in the control group. Combined medication of risedronate sodium and SERM (raloxifene) performs better in treatment of osteoporosis than the single use of risedronate sodium, without the deterioration of adverse effect of medication.

[Antiestrogen therapy in the treatment of breast neoplasms]

During recent years the development of hormone therapy for the treatment breast neoplasms has seen, in addition to classic aspecific antiestrogens (AE) like tamoxifen (TAM) and to a lesser extent toremifen, a major development of new molecules divided into two groups: the first is the so-called selective estrogen receptor modulators (SERMs), the most important of which is Raloxifen, which mediate estrogen-agonist effects in some tissues and estrogen-antagonist effects in others; the second group includes the aromatase inhibitors (AI), important enzymes for peripheral estrogen conversion. Some studies compare or associate classic AE with the new SERMs and AI, both in adjuvant therapy and in treatment for advanced forms. Other trials assess the anti-osteoporotic activity of some SERMs which present concomitant inhibitory activity on the breast and endometrium.

The hemorheological effects of raloxifene in postmenopausal women with osteoporosis. Results of a 3-year placebo-controlled clinical trial

Raloxifene, the prototype of the selective estrogen receptor modulators, has been associated with an increased risk of venous thromboembolism. As hemorheological factors may be involved in thrombus formation this placebo-controlled study investigated whether raloxifene was associated with changes in determinants of blood viscosity. Fifty-seven post-menopausal women were randomly assigned to receive placebo, raloxifene 60 mg/day, or raloxifene 120 mg/day for 36 months. Venous blood samples were collected at baseline and at 12-monthly intervals and used to measure hematocrit, whole blood and plasma viscosity and plasma fibrinogen concentration. Time- and treatment-related changes in the grouped and pooled data was analysed using ANOVA with repeated measures and correlation matrices. The mean values of all the hemorheological indices showed small inconsistent changes within the normal reference range over the 36-month period of the study. There was a small but significant decrease over time in high shear rate blood viscosity and plasma viscosity in raloxifene-treated subjects compared to those receiving placebo (p<0.05). Correlation analyses showed the anticipated relationships between blood viscosity and hematocrit and plasma viscosity levels and also between plasma viscosity and plasma fibrinogen concentration. No subject developed a thromboembolic vascular event during the study. These results show that compared with placebo treated-subjects, long-term raloxifene treatment in post-menopausal women, at a dose of either 60 or 120 mg daily, was not associated with adverse changes in hemorheological factors that may contribute to venous thromboembolism.

[Hormonal replacement therapy and selective estrogen receptor modulators in prevention of cardiovascular disease]

Postmenopausal women are at higher risk of cardiovascular disease because of increased prevalence of major coronary artery disease risk factors. The protective activity on cardiovascular system of estrogen was postulated. The data from many studies indicate favourable effect of estrogen replacement therapy. However prospective, randomized clinical trials have not proved protective influence of hormonal replacement therapy (HRT) on cardiovascular system. Moreover it was found to increased the risk of cardiovascular disease events. This article presents mechanism of estrogens activity and results of major clinical trials concerning hormonal replacement therapy. Activity of selective estrogen receptor modulators (SERMs) was also described.

The protection against trimetrexate cytotoxicity in human bone marrow by sequence-dependent administration of raloxifene, 5-fluorouracil/trimetrexate

BACKGROUND

Currently, one of the most effective strategies for the treatment and prevention of breast cancer is the use of drugs that block estrogen action in the breast. The success of the first clinically relevant selective estrogen receptor modulator (SERM), tamoxifen, provided the foundation for further testing of this drug to reduce breast cancer incidence in high-risk women. However, the negative effects associated with the long-term use of tanrhoxifen have initiated the search for compounds that are more effective but less toxic. The discovery of raloxifene (RAL), which functions as a potent antiestrogen in the breast but an estrogen receptor (ER) agonist in the bone and cardiovascular system with very little uterotropic activity, provided an alternative strategy to the targeted use of tamoxifen. The aim of this study was to evaluate RAL in combination with 5-fluorouracil (5-FU)/trimetrexate (TMX) to determine the most effective regimes and cellular mechanism of action to mitigate trimetrexate cytotoxicity in human bone marrow cells.

MATERIALS AND METHODS

The cell viability was performed using the Quick Cell Proliferation Assay by exposing the cells to TMX, 5-FU and RAL alone; RAL 24 h prior to 5-FU followed 2 h by TMX, and 5-FU 2 h prior to TMX followed 24 h by RAL determined the sequence-dependent interaction between TMX, 5-FU and RAL on the proliferation.

RESULTS

The growth rate in MCF-7 in late RAL was 34.75 +/- 4.79% of the control, whereas in bone marrow the same drug combination exhibits a significant protection against TMX cytotoxicity with late RAL yielding 51.25 +/- 4.43% of the control. The findings were also supported by Cell flow cytometry and Western blot analysis.

CONCLUSION

Sequence-dependent administration of RAL in combination with 5-FU/TMX can act against TMX toxicity in human bone marrow, while not affecting the maximum inhibitory effect of TMX in breast cancer.

Pharmacologic prevention of osteoporotic fractures

Osteoporosis is characterized by low bone mineral density and a deterioration in the microarchitecture of bone that increases its susceptibility to fracture. The World Health Organization defines osteoporosis as a bone mineral density that is 2.5 standard deviations or more below the reference mean for healthy, young white women. The prevalence of osteoporosis in black women is one half that in white and Hispanic women. In white women 50 years and older, the risk of osteoporotic fracture is nearly 40 percent over their remaining lifetime. Of the drugs that have been approved for the prevention or treatment of osteoporosis, the bisphosphonates (risedronate and alendronate) are most effective in reducing the risk of vertebral and nonvertebral fractures. Risedronate has been shown to reduce fracture risk within one year in postmenopausal women with osteoporosis and in patients with glucocorticoid-induced osteoporosis. Hormone therapy reduces fracture risk, but the benefits may not outweigh the reported risks. Teriparatide, a recombinant human parathyroid hormone, reduces the risk of new fractures and is indicated for use in patients with severe osteoporosis. Raloxifene has been shown to lower the incidence of vertebral fractures in women with osteoporosis. Salmon calcitonin is reserved for use in patients who cannot tolerate bisphosphonates or hormone therapy.

[SERM & bone metabolism: protective effects of SERM against fracture risk and its long-term beneficial effects]

The Multiple Outcomes of Raloxifene Evaluation (MORE) Trial enrolled 7,705 women with osteoporosis, defined by prevalent vertebral fractures and/or a bone mineral density (BMD) T score at -2.5 or below, who were treated with placebo or raloxifene at a dosage of 60 or 120 mg/day for 3 years. Raloxifene hydrochloride therapy significantly reduces the risk for vertebral fractures at 3 and 4 years administration group. The fact that Raloxifene administration causes the significant 25% reduction in overall risks in postmenopausal women indicate a favorable risk-benefit profile. These data suggested that raloxifene is effective to protect from the occurrence of bone fracture without causing increases of breast cancer and endometrial cancer, and improve overall health conditions in postmenopausal women.

Enhanced oral bioavailability of levormeloxifene and raloxifene by nanoemulsion: simultaneous bioanalysis using liquid chromatography-tandem mass spectrometry

Aim & objective: Levormeloxifene (L-ORM) and raloxifene (RAL) are selective estrogen receptor modulators used in the treatment of postmenopausal osteoporosis and breast cancer. Here, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous estimation of both drugs. Materials & methods: A quality-by-design (QbD) approach was used for the optimization of the nanoemulsion, and US FDA guidelines were followed for method validation. Results: Multiple reaction monitoring transitions were used for L-ORM (459.05→98.50), RAL (475.00→112.02) and internal standard (180.10→110.2). Analytes were resolved in a C18 column with 80:20 v/v% acetonitrile (ACN), 0.1% formic acid in triple-distilled water as a mobile phase. The developed method was linear over a concentration range of 1-600 ng/ml. Pharmacokinetic results of free L-ORM-RAL and the L-ORM-RAL nanoemulsion showed Cmax of free L-ORM - 70.65 ± 16.64, free RAL 13.53 ± 2.72, L-ORM nanoemulsion 65.07 ± 14.0 and RAL-nanoemulsion 59.27 ± 17.44 ng/ml. Conclusion: Future findings will contribute to the treatment of postmenopausal osteoporosis and breast cancer using L-ORM and RAL.

Raloxifene attenuation of 5-FU/methotrexate cytotoxicity in human breast cancer cells: the importance of sequence in combination chemotherapy

BACKGROUND

The selective estrogen receptor modulator raloxifene (RAL), used to treat and prevent osteoporosis, is under investigation for its use in the treatment and prevention of breast cancer. RAL in combination with the antimetabolites methotrexate (MTX) and 5-fluorouracil (5-FU) has not been extensively studied. Because RAL and the antimetabolites target different phases of the cell cycle and exhibit different mechanisms of action and clinical toxicity, the effects of sequence of administration on the growth inhibition of MCF-7 human breast cancer cells were investigated.

MATERIALS AND METHODS

MCF-7 human breast cancer cells were exposed to vehicle alone, 10 microM MTX, 1 microM 5-FU, 10 microM RAL, 10 microM RAL 24 hours prior to 1 microM 5-FU followed 2 hours later by 10 microM MTX, and 1 microM 5-FU 2 hours prior to 10 microM MTX followed 24 hours later by 10 microM RAL. The cells were evaluated for viability and proliferation. The retinoblastoma (Rb) protein, a cell cycle regulator which when phosphorylated allows the progression of cells from G1- to S-phase, was used as a marker to determine the effects of early RAL and late RAL on cellular progression at the molecular level.

RESULTS

Early RAL administration exhibited a cell viability of 66.83 +/- 6.17% of the control. However, late RAL administration exhibited cell viability 39.40 +/- 17.03% of the control. Late RAL was a more cytotoxic combination than RAL alone or early RAL. These findings from manual cell counting were also supported by cell flow cytometric analysis and Western blot data.

CONCLUSION

Late RAL in combination with 5-FU and MTX, due to greater cytotoxicity, is a more desirable combination to treat breast cancer than RAL alone.

[Raloxifene (Celvista, Evista)]

The prevention of osteoporotic fractures in post-menopausal women must be viewed in the framework of the treatment of menopause. SERMs ("Selective Estrogen Receptor Modulators") derivative from steroid hormones have estrogenic and antiestrogenic properties according to the substance and the target tissue. Raloxifene is a second generation SERM. It increases bone mass by 1 to 3% according to the measured site and, after 3 years of therapy at the dose of 60 mg per day, it reduces the incidence of vertebral fractures by 30 to 50% if patients have or do not have vertebral fractures before therapy. This drug is approved for the prevention of vertebral fractures in post-menopausal women at increased risk of fractures. A significant reduction in the incidence of hip fractures has not been demonstrated. Raloxifene exerts favorable effects on cardiovascular risk factors but one has to wait for the results of controlled prospective trials before concluding that raloxifene reduces the risk of atherogeniec disease. Preliminary results indicate a substantial reduction of the risk of invasive breast cancer, still to be confirmed. The incidence of vaginal bleeding does not differ from placebo as raloxifene does not stimulate endometrial proliferation. The most serious adverse event, although infrequent, consists in an increase of the relative risk of thromboembolic disease by 3.1 as compared to placebo. Longer term studies are necessary to compare raloxifene with the estrogen replacement therapy and to determine the extra-bone effects.

Effect of raloxifene on breast cancer cell Ki67 and apoptosis: a double-blind, placebo-controlled, randomized clinical trial in postmenopausal patients

PURPOSE

Raloxifene is a selective estrogen receptor (ER) modulator approved for prevention and treatment of postmenopausal osteoporosis. This is an exploratory study of raloxifene in primary breast cancer patients.

EXPERIMENTAL DESIGN

Postmenopausal women (50-80 years of age), with histological or cytological diagnosis of stage I or II primary breast cancer, were randomly assigned to 14 days of placebo, 60 mg/day raloxifene, or 300 mg twice daily (600 mg/day) of raloxifene. A core biopsy of the primary tumor was obtained before therapy, and a representative sample of the excised tumor was obtained from the operative specimen after treatment. Paired baseline and endpoint biopsies from each patient were analyzed for Ki67, apoptosis, and estrogen and progesterone receptors. Treatment group differences in efficacy measurements were primarily evaluated for baseline-to-endpoint change and percentage change using a one-way ANOVA with treatment as the fixed effect.

RESULTS

Of 167 enrolled patients, 143 had evaluable efficacy data. Most breast cancer cases were invasive (98.6%), stage I (76.6%), and ER-positive (83.2%). In patients with ER-positive tumors, Ki67 increased 7% from baseline on placebo and decreased by 21% on 60 mg/day raloxifene (P = 0.015 versus placebo) and by 14% on 600 mg/day raloxifene (P = 0.064 versus placebo). Raloxifene did not affect apoptosis. ER decreased significantly with 60 mg/day or 600 mg/day raloxifene compared with placebo (P < 0.01 for each comparison). Raloxifene had no statistically significant effects on Ki67 among patients with ER-negative tumors. There were no treatment differences in adverse events.

CONCLUSION

In this exploratory trial, 60 mg/day raloxifene showed a significant antiproliferative effect in ER-positive breast cancer, demonstrated by the decrease in Ki67, with no effect in ER-negative cancer. This provides support for raloxifene having a breast cancer preventive effect in postmenopausal women.

Effect of raloxifene and clodronate on bone density in postmenopausal osteoporotic women

The aim of the present study was to determine the safety and efficacy of combined therapy with raloxifene (RLX) and clodronate (CLD) in postmenopausal women. We enrolled 45 women with postmenopausal osteoporosis. The patients were randomly assigned to two different therapeutic groups: RLX 60 mg/day (n = 23) and RLX 60 mg/day plus CLD 100 mg intramuscularly (i.m.) once every 10 days (n = 22); 1 g of calcium and 800 IU of vitamin D3 were also given daily to both groups. Lumbar and femoral bone mineral density (BMD) were assessed at baseline and after 12 months of therapy using the dual X-ray absorptiometry technique (Norland XR36). We measured the bone turnover markers NTx and CTx, bone alkaline phosphatase (BAP) and osteocalcin at baseline and after 12 months of therapy. Our data demonstrate that 1 year of combined RLX+CLD therapy induced a higher increase in lumbar BMD than treatment with RLX alone as well as a major decrease in bone resorption markers, suggesting an additive effect of CLD on bone mass and inhibition of bone turnover. Furthermore, after 1 year of therapy levels of bone formation markers (osteocalcin and BAP) had increased in both groups, but the increase in osteocalcin and BAP was significantly higher in the RLX+CLD treated group, suggesting that, in addition to its inhibitory effects on resorption, CLD might also have stimulatory effects on mature osteoblast activity.

The effects of short-term raloxifene therapy on fibrinolysis markers: TAFI, tPA, and PAI-1

BACKGROUND

Markers of fibrinolysis, thrombin-activatable fibrinolysis inhibitor (TAFI), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) levels were studied for the evaluation of short-term effects of raloxifene administration in postmenopausal women.

METHODS

Thirty-nine postmenopausal women with osteopenia or osteoporosis were included in this prospective, controlled clinical study. Twenty-five women were given raloxifene hydrochloride (60 mg/day) plus calcium (500 mg/day). Age-matched controls (n = 14) were given only calcium. Plasma TAFI, tPA, and PAI-1 antigen levels were measured at baseline and after 3 months of treatment by commercially available ELISA kits. Variations of individuals were assessed by Wilcoxon's test. Relationship between those markers and demographic characteristics were investigated.

RESULTS

Three months of raloxifene treatment was associated with a significant decrease in the plasma TAFI antigen concentrations (16% change, P < 0.01), and a significant increase in tPA antigen concentrations (25% change, P < 0.05). A significant correlation was found between baseline TAFI antigen concentrations and the duration of amenorrhea (P < 0.05; r = 0.33).

CONCLUSION

We suggest that the increased risk of venous thromboembolism due to raloxifene treatment may be related to increased tPA levels, but not TAFI levels.

[Economics of medicament therapies for osteoporosis]

For treatment of osteoporosis, medical costs range within 10% among administrations of alfacalcidol, raloxifene and weekly alendronate, because costs of the drugs are shared about 50% of medical costs. Medical costs of the patients suffered from mild lumbago, severe lumbago and femoral neck fracture are compared between the patients with and without the medicament therapies. Preventions of lumbago and fracture by the drugs reduce maximally 16.5% of medical costs. Economics of various therapies to prevent femoral neck fracture in whole Japan show that hip protector gains 73.1 billion yen and medicament therapies lose minimally 826.9 billion yen annually.