Effect of zoledronic acid compared with raloxifene on bone turnover markers in postmenopausal women with low bone density

Treatment pattern in postmenopausal women with osteoporosis: a population-based cohort study in South Korea

INTRODUCTION

The treatment landscape of postmenopausal osteoporosis (OP) in an Asian population is yet to be explored.

MATERIALS AND METHODS

We conducted a retrospective cohort study to explore treatment patterns and characteristics associated with treatment interruption in postmenopausal women diagnosed with OP between 2008 and 2014. Treatment pattern assessment included the initial distribution of OP medications and treatment interruption rate according to the treatment groups during a 3-year follow-up period. We used multivariate logistic regression to estimate odds ratio (OR) and 95% confidence interval (CI) to identify factors associated with treatment interruption.

RESULTS

Of 21,813 patients, 87.9% initiated oral bisphosphonates (BP), followed by ibandronate intravenous (IV; 5.4%), selective estrogen receptor modulators (SERMs; 5.2%), pamidronate IV (1.4%) and zoledronic acid (0.06%). Treatment interruption was most notable in the first year of treatment, with cumulative treatment interruption rates highest for oral BP (76.3%) and lowest for pamidronate IV (50.5%). Compared to oral BP users, users of ibandronate IV (OR 0.34, 95% CI 0.30-0.39), pamidronate IV (0.49, 0.39-0.63), zoledronic acid (0.26, 0.09-0.77), and SERMs (0.50, 0.44-0.57) were less likely to interrupt treatment. Of characteristics assessed, presence of rheumatoid arthritis increased the odds of treatment interruption in ibandronate IV group (3.94, 2.12-7.33), and concomitant use of glucocorticoids for oral BP (1.11, 1.03-1.19) and pamidronate IV (2.04, 1.06-3.93) groups, respectively.

CONCLUSION

Given the frequent treatment interruptions across all OP medications, our findings on the factors associated with treatment interruption will serve to implement targeted interventions in reinforcing persistence to OP treatment.

(-)-Epigallocatechin-3-Gallate (EGCG) Enhances Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells

Osteoporosis is the second most-prevalent epidemiologic disease in the aging population worldwide. Cross-sectional and retrospective evidence indicates that tea consumption can mitigate bone loss and reduce risk of osteoporotic fractures. Tea polyphenols enhance osteoblastogenesis and suppress osteoclastogenesis in vitro. Previously, we showed that (-)-epigallocatechin-3-gallate (EGCG), one of the green tea polyphenols, increased osteogenic differentiation of murine bone marrow mesenchymal stem cells (BMSCs) by increasing the mRNA expression of osteogenesis-related genes, alkaline phosphatase activity and, eventually, mineralization. We also found that EGCG could mitigate bone loss and improve bone microarchitecture in ovariectomy-induced osteopenic rats, as well as enhancing bone defect healing partially via bone morphogenetic protein 2 (BMP2). The present study investigated the effects of EGCG in human BMSCs. We found that EGCG, at concentrations of both 1 and 10 µmol/L, can increase mRNA expression of BMP2, Runx2, alkaline phosphatase (ALP), osteonectin and osteocalcin 48 h after treatment. EGCG increased ALP activity both 7 and 14 days after treatment. Furthermore, EGCG can also enhance mineralization two weeks after treatment. EGCG without antioxidants also can enhance mineralization. In conclusion, EGCG can increase mRNA expression of BMP2 and subsequent osteogenic-related genes including Runx2, ALP, osteonectin and osteocalcin. EGCG further increased ALP activity and mineralization. Loss of antioxidant activity can still enhance mineralization of human BMSCs (hBMSCs).

Comparison of the prescribing pattern of bisphosphonate and raloxifene in Korean women with osteoporosis: from a national health insurance claims database

This study aimed to evaluate the differences of prescribing pattern between bisphosphonate and raloxifene users among Korean women with osteoporosis, focusing on the underlying conditions, concurrent medications, nature of healthcare utilization, and regional disparity. We used the Health Insurance Review and Assessment Service National Patients Sample database of the year 2010. Study subjects were defined as female osteoporosis patients aged over 50 years with both the diagnosis of osteoporosis and prescriptions of bisphosphonate or raloxifene. The frequency and the proportion of bisphosphonate and raloxifene were compared using chi-square test and the trend of the proportion using the Cochran–Armitage test. Medications were quantified as defined daily doses per 1,000 patients per day. The prescription pattern was visualized by using the Quantum Geographic Information Systems program. Of the 1,367,367 people who utilized medical services in 2010, the final number of study subjects was 26,881—26,032 (96.8%) bisphosphonate and 849 (3.2%) raloxifene recipients. Raloxifene users were younger than bisphosphonate users and were more frequently patients with a lipid disorder (16.0% vs. 22.1%, p-value < 0.0001), rheumatic disease (4.0% vs. 6.1%, p-value = 0.0024), hot flash (1.8% vs. 6.1%, p <0.0001), and coronary artery disease (1.2% vs. 2.8%, p< 0.0001). The proportion of raloxifene users was higher in tertiary care institutions (21.6% vs. 44.7%, p-value < 0.0001). A regional distribution showed that raloxifene use was higher in the Seoul metropolitan area. These differences in demographic and clinical profiles of each recipient may influence prescription decisions.

Treatment of post-menopausal osteoporosis: beyond bisphosphonates

Osteoporosis is a highly prevalent condition, characterized by compromised bone strength and fragility fractures and with an important associated socio-economic burden. Bisphosphonates are well established as the first line treatment for osteoporosis. However, while randomized control trials have in general demonstrated reasonable anti-fracture efficacy at the spine, they have shown moderate reduction in fracture incidence for non-vertebral sites. Furthermore, oral bisphosphonates are commonly associated with adverse gastrointestinal effects and both oral and parenteral bisphosphonates have been linked with osteonecrosis of the jaw and atypical femoral fracture, two rare but debilitating side effects. In addition, bisphosphonates are not recommended in patients with GFR <35 ml/min/1.73 m(2). Hence, there is a clear requirement for newer agents, which are able to reduce fracture risk further, whilst overcoming the limitations of bisphosphonates. Over the past 20 years, knowledge and a deeper understanding of the various signalling pathways involved in bone remodelling has increased, enabling identification of additional targets for therapy. This review focuses on these newer therapies and includes anti-resorptive agents such as raloxifene and other selective oestrogen receptor modulators, the monoclonal antibody denosumab (which inhibits the RANKL pathway), odanacatib, a cathepsin K inhibitor and the anabolic agents, PTH analogue; PTH (1-34) and anti-sclerostin antibodies (activator of the Wnt pathway). Strontium ranelate will not be reviewed as recent reports highlight concerns surrounding its cardiovascular safety and together with an apparent increased risk of thrombosis, its future use remains uncertain. Some of these agents such as raloxifene, denosumab and teriparatide are already in clinical use whilst others are at varying stages of development. This review will provide an overview of the mechanisms of action of these therapeutic agents on the skeleton and assess their efficacy in osteoporosis and fracture prevention.

Multiple doses of sclerostin antibody romosozumab in healthy men and postmenopausal women with low bone mass: a randomized, double-blind, placebo-controlled study

Romosozumab (formerly AMG 785/CDP7851) is a monoclonal antibody that blocks sclerostin from inhibiting osteoblast maturation and function. This double-blind, placebo-controlled, randomized, ascending multiple-dose study enrolled 32 postmenopausal women and 16 healthy men with low bone mass. Women received six doses of 1 or 2 mg/kg once every 2 weeks (Q2W) or three doses of 2 or 3 mg/kg once every 4 weeks (Q4W) or placebo; and men received 1 mg/kg Q2W or 3 mg/kg Q4W or placebo. Mean serum romosozumab exposures increased approximately dose-proportionally. Romosozumab increased serum type 1 aminoterminal propeptide (PINP) by 66-147%, decreased serum C-telopeptide (sCTX) by 15-50%, and increased lumbar spine bone mineral density by 4-7%. Two subjects developed neutralizing antibodies without discernable effects on pharmacokinetics, pharmacodynamics, or safety. Adverse event rates were balanced between groups without any significant safety findings. These data support continued investigation of sclerostin inhibition in disorders that could benefit from increased bone formation.