The treatment of severe postmenopausal osteoporosis : a review of current and emerging therapeutic options

Increased bone mineral density for 1 year of romosozumab, vs placebo, followed by 2 years of denosumab in the Japanese subgroup of the pivotal FRAME trial and extension

Romosozumab, which binds sclerostin, rebuilds the skeletal foundation before transitioning to antiresorptive treatment. This subgroup analysis of an international, randomized, double-blind study in postmenopausal women with osteoporosis showed efficacy and safety outcomes for romosozumab followed by denosumab in Japanese women were generally consistent with those for the overall population.

PURPOSE

In the international, randomized, double-blind, phase 3 FRActure study, in postmenopausal woMen with ostEoporosis (FRAME; NCT01575834), romosozumab followed by denosumab significantly improved bone mineral density (BMD) and reduced fracture risk. This report evaluates Japanese women in FRAME.

METHODS

Postmenopausal women with osteoporosis (T-score - 3.5 to - 2.5 at total hip or femoral neck) received romosozumab 210 mg or placebo subcutaneously monthly for 12 months, then each group received denosumab 60 mg subcutaneously every 6 months for 24 months. The key endpoint for Japanese women was BMD change. Other endpoints included new vertebral, clinical, and nonvertebral fracture; the subgroup analysis did not have adequate power to demonstrate statistically significant reductions.

RESULTS

Of 7180 enrolled subjects, 492 (6.9%) were Japanese (247 romosozumab, 245 placebo). BMD increases from baseline were greater (P < 0.001) for romosozumab-to-denosumab than placebo-to-denosumab at the lumbar spine (36 months, 12.7%), total hip (4.2%), and femoral neck (4.1%). Fracture risk was lower through 36 months for romosozumab-to-denosumab vs placebo-to-denosumab for new vertebral (1.7% vs 4.5%; relative risk reduction (RRR) 63%, P = 0.070), clinical (3.2% vs 7.3%; RRR 53%, P = 0.072), nonvertebral (2.8% vs 6.1%; RRR 50%, P = 0.12), and all other fracture types evaluated. Rates of adverse events and positively adjudicated serious cardiovascular events were generally balanced between groups.

CONCLUSIONS

Efficacy and safety for romosozumab-to-denosumab were similar between Japanese women and the overall population. The sequence of romosozumab to rebuild the skeletal foundation before transitioning to antiresorptive treatment with denosumab is a promising regimen for Japanese postmenopausal women with osteoporosis at high risk of fracture.

The functional mechanism of simvastatin in experimental osteoporosis

Osteoporosis is a systemic and metabolic bone disease. New drugs with good curative effect, fewer side effects, and high safety need to be developed urgently. Recently, simvastatin has been used to treat osteoporosis more frequently; however, its clinical effect and treatment mechanism are still unknown. With the use of animal models, the treatment effectiveness of simvastatin on experimental osteoporosis was investigated and the functional mechanism was preliminarily explored. The results show that simvastatin significantly increased the mechanical parameters such as maximum load, stiffness, and energy-absorbing capacity, and improved the microarchitecture. They indicated that the antiosteoporosis activity of simvastatin may be due to the promotion of proliferation and differentiation of osteoblasts. Simvastatin was effective in treating experimental osteoporosis. This study provides necessary experimental evidence for the clinical application of simvastatin in osteoporosis treatment.

Effects of OsteoKing on osteoporotic rabbits

Heng-Gu-Gu-Shang-Yu-He-Ji, also known as OsteoKing, is used as a herbal Traditional Chinese Medicine for the treatment of bone disease, including femoral head necrosis and osteoarthritis. However, whether OsteoKing has anti-osteoporotic properties has remained to be elucidated. The purpose of the present study was therefore to investigate the effects of OsteoKing on ovariectomy-induced osteoporosis in rabbits. Female New Zealand white rabbits were randomly divided into an ovariectomized (OVX) group and a sham-surgery group. The rabbits in the OVX group were subjected to an ovariectomy, while the rabbits in the sham group were subjected to the removal of an area of fat near the two ovaries. Bone mineral density, mechanical properties, serum biochemical parameters and micro-architecture were examined at 150 days post-OVX to characterize the experimental animal model. Once the osteoporotic rabbit model had been established, the rabbits in the OVX group were divided into the following groups: Model group, nilestriol group and 300 and 600 mg/kg OsteoKing groups, containing 16 rabbits in each group. OsteoKing and nilestriol were administered orally. The bone mineral density, mechanical properties, serum biochemical parameters, histology and micro-architecture were examined using dual-energy X-ray absorptiometric analysis, mechanical assessments, enzyme-linked immunosorbent assays, histopathological evaluation and micro-computerized tomography examination following 60 days and 120 days of treatment, respectively. Treatment with OsteoKing led to an elevation in the bone mineral density of the vertebra and serum phosphorus levels, reduced serum concentrations of osteocalcin, procollagen type I N-terminal peptide, tartrate-resistant acid phosphatase 5b and cross-linked N-telopeptide of type I collagen, improved mechanical properties (maximum load, stiffness and energy absorption capacity), and micro-architecture of the lumbar vertebra in the OVX osteoporotic rabbit model following treatment for 120 days. In conclusion, it was demonstrated that OsteoKing is effective in the prevention of estrogen deficiency-associated bone loss and may be a promising drug for the treatment of post-menopausal osteoporosis.

Pulse treatment with zoledronic acid causes sustained commitment of bone marrow derived mesenchymal stem cells for osteogenic differentiation

The aminobisphosphonate zoledronic acid (ZA) is a bone seeking specific inhibitor of protein farnesylation and geranylgeranylation, which causes inhibition of osteoclast function and apoptosis. It is widely used as an osteoclast targeted antiresorptive treatment of metastatic bone disease, Paget's disease and osteoporosis. Mesenchymal stem cells (MSC) and osteoblast precursors can also be targets of bisphosphonates, but the clinical relevance of these effects is under debate. We show here that ZA in vitro causes inhibition of proliferation and induction of apoptosis in hMSC, when applied in concentrations of 20 and 50 microM for more than 24 h which can be rescued by treatment with 10 microM geranylgeranyl pyrophosphate (GGPP). However, pulse stimulation for 3 and 6 h with these concentrations and subsequent culture for up to 2 weeks under osteogenic conditions exerts sustained regulation of osteogenic marker genes in hMSC. The effect on gene regulation translates into marked enhancement of mineralization, as shown by alizarin red and alkaline phosphatase staining after 4 weeks of osteogenic culture. ZA, when applied as a pulse stimulus, might therefore also stimulate osteogenic differentiation in vivo, since muM plasma concentrations can be achieved by intravenous application of 5 mg in patients. These data set the stage for the future dissection of the effects of ZA and other aminobisphosphonates on cells beyond osteoclasts, with respect to cell differentiation in benign metabolic and to antitumor efficacy in metastatic bone diseases, as well as adverse events due to putative substance accumulation in bone during long-term treatment.

The discovery of novel calcium sensing receptor negative allosteric modulators

The design and profile of a series of zwitterionic calcium sensing receptor negative allosteric modulators is described. Evaluation of key analogues using a rat model demonstrate a robust response, significantly improved potency over ronacaleret and have the potential as an oral, anabolic treatment for osteoporosis.

Alendronate decreases orthotopic PC-3 prostate tumor growth and metastasis to prostate-draining lymph nodes in nude mice

Background

Metastatic prostate cancer is associated with a high morbidity and mortality but the spreading mechanisms are still poorly understood. The aminobisphosphonate alendronate, used to reduce bone loss, has also been shown to inhibit the invasion and migration of prostate cancer cells in vitro. We used a modified orthotopic PC-3 nude mouse tumor model of human prostate cancer to study whether alendronate affects prostate tumor growth and metastasis.

Methods

PC-3 cells (5 × 10⁵) were implanted in the prostates of nude mice and the mice were treated with alendronate (0.5 mg/kg/day in PBS, s.c.) or vehicle for 4 weeks. After sacrifice, the sizes of tumor-bearing prostates were measured and the tumors and prostate-draining regional iliac and sacral lymph nodes were excised for studies on markers of proliferation, apoptosis, angiogenesis and lymphangiogenesis, using histomorphometry and immunohistochemistry.

Results

Tumor occurrence in the prostate was 73% in the alendronate-treated group and 81% in the control group. Mean tumor size (218 mm³, range: 96–485 mm³, n = 11) in the alendronate-treated mice was 41% of that in the control mice (513 mm³, range: 209–1350 mm³, n = 13) (p < 0.05). In the iliac and sacral lymph nodes of alendronate-treated mice, the proportion of metastatic area was only about 10% of that in control mice (p < 0.001). Immunohistochemical staining of tumor sections showed that alendronate treatment caused a marked decrease in the number of CD34-positive endothelial cells in tumors (p < 0.001) and an increase in that of ISEL positive apoptotic cells in tumors as well as in lymph node metastases (p < 0.05) compared with those in the vehicle-treated mice. The density of m-LYVE-1-stained lymphatic capillaries was not changed.

Conclusion

Our results demonstrate that alendronate treatment opposes growth of orthotopic PC-3 tumors and decreases tumor metastasis to prostate-draining lymph nodes. This effect could be at least partly explained by decreased angiogenesis and increased apoptosis. The results suggest that bisphosphonates have anti-tumoral and anti-invasive effects on primary prostate cancer.

Effect of teriparatide on bone mineral density and biochemical markers in Japanese women with postmenopausal osteoporosis: a 6-month dose-response study

The dose-response efficacy and safety with three doses of teriparatide and placebo was assessed, using once-daily subcutaneous injections for 24 weeks, in Japanese postmenopausal women with osteoporosis at high risk of fracture for reasons of preexisting fracture(s), advanced age, and/or low bone mineral density (BMD). In this multicenter, randomized, placebo-controlled study, 159 subjects were randomized and 154 subjects were included for analysis. Teriparatide (10-microg, 20-microg, and 40-microg doses) showed a statistically significant increase with increasing treatment dose as assessed by the percent change of lumbar spine BMD from baseline to endpoint using Williams' test when compared with placebo (P < 0.001). The mean (+/-SD) percent change in lumbar spine, femoral neck, and total hip BMD with the 20-microg dose from baseline to endpoint was 6.40% +/- 4.76%, 1.83% +/- 7.13%, and 1.91% +/- 3.60%, respectively. Rapid and sustained increases in bone formation markers [type I procollagen N-terminal propeptide (PINP), type I procollagen C-terminal propeptide (PICP), and bone-specific alkaline phosphatase (BAP)], followed by late increases in a bone resorption marker [type I collagen cross-linked C-telopeptide (CTX)], were observed for the teriparatide treatment groups (20-microg, 40-microg), suggesting a persistent, positive, balanced anabolic effect of teriparatide. Optimal adherence was achieved by this daily self-injection treatment. Regarding safety, most of the adverse events were mild to moderate in severity. No study drug-or study procedure-related serious adverse events were reported during the treatment period. These results observed in Japanese patients may support the observation that teriparatide stimulates bone formation in patients with osteoporosis at a high risk of fracture.

Alendronate therapy in cyclosporine-induced alveolar bone loss in rats

BACKGROUND AND OBJECTIVE

Cyclosporine A is an immunosuppressive drug that is widely used in organ transplant patients as well as to treat a number of autoimmune conditions. Bone loss is reported as a significant side-effect of cyclosporine A use because this can result in serious morbidity of the patients. As we have shown that cyclosporine A-associated bone loss can also affect the alveolar bone, the purpose of this study was to evaluate the effect of the concomitant administration of alendronate on alveolar bone loss in a rat model.

MATERIAL AND METHODS

Forty Wistar rats (10 per group) were given cyclosporine A (10 mg/kg, daily), alendronate (0.3 mg/kg, weekly), or both cyclosporine A and alendronate, for 60 d. The control group received daily injections of sterile saline. The expression of proteins associated with bone turnover, including osteocalcin, alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP), and also the calcium levels, were evaluated in the serum. Analysis of the bone volume, alveolar bone surface, the number of osteoblasts per bone surface and the number of osteoclasts per bone surface around the lower first molars was also performed.

RESULTS

The results indicate that cyclosporine A treatment was associated with bone resorption, represented by a decrease in the bone volume, alveolar bone surface and the number of osteoblasts per bone surface and by an increase in the number of osteoclasts per bone surface and TRAP-5b. These effects were effectively counteracted by concomitant alendronate administration.

CONCLUSION

It is concluded that concomitant administration of alendronate can prevent cyclosporine A-associated alveolar bone loss.

Natural products as alternative treatments for metabolic bone disorders and for maintenance of bone health

Bone metabolism involves a complex balance between the deposition of matrix and mineralization and resorption. There is now good evidence that dietary components and herbal products can influence these processes, particularly by inhibiting bone resorption, thus having beneficial effects on the skeleton. For example, it has been reported that a number of common vegetables, including onion, garlic and parsley, can inhibit bone resorption in ovariectomized rats. Essential oils derived from sage, rosemary, thyme and other herbs inhibit osteoclast activity in vitro and in vitro and leading to an increase in bone mineral density. Soya, a rich source of isoflavones, has shown promising results and epidemiological evidence to support a use in maintaining bone health, and various traditional herbal formulae in Chinese and Ayurvedic medicine also have demonstrable effects in pharmacological models of osteoporosis. Recently, cannabinoids have been described as having positive effects on osteoblast differentiation, and the presence of cannabinoid receptors in bone tissue indicates a more complex role in bone metabolism than previously thought. The first part of this review briefly discusses normal bone metabolism and disorders caused by its disruption, with particular reference to osteoporosis and current pharmacological treatments. The effects of natural products on bone and connective tissue are then discussed, to include items of diet, herbal extracts and food supplements, with evidence for their efficacy outlined.

Stimulatory effects of extract prepared from the bark ofCinnamomum cassia blume on the function of osteoblastic MC3T3-E1 cells

The ethanol extract from the bark of Cinnamomum cassia Blume (CCE) was tested for estrogenic activity. CCE (4-60 microg/mL) significantly induced the growth of MCF-7 cells, an ER-positive human breast cancer cell line, over that of untreated control cells (p < 0.05). In the ER competitive binding assay, CCE showed higher affinity with ERbeta compared with ERalpha. To investigate the bioactivities of CCE, which act on bone metabolism, the effects of CCE on the function of osteoblastic MC3T3-E1 cells and the production of local factors in osteoblasts were studied. CCE (4-60 microg/mL) dose-dependently increased the survival of MC3T3-E1 cells. In addition, CCE (10 and 50 microg/mL) increased alkaline phosphatase (ALP) activity, collagen synthesis and osteocalcin secretion in MC3T3-E1 cells. Treatment with CCE (10 and 50 microg/mL) prevented apoptosis induced by TNF-alpha (10(-10) m) in osteoblastic cells. In the presence of TNF-alpha, culture with CCE (10-100 microg/mL) for 48 h inhibited the production of IL-6 and nitric oxide in osteoblastic MC3T3-E1 cells. These results suggest that Cinnamomum cassia has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention of osteoporosis and inflammatory bone diseases.