Injectable bisphosphonates in the treatment of postmenopausal osteoporosis

Tumor necrosis factor alpha suppresses osteogenic differentiation of MSCs by inhibiting semaphorin 3B via Wnt/β-catenin signaling in estrogen-deficiency induced osteoporosis

The proinflammatory cytokines, especially tumor necrosis factor alpha (TNF-α), have been shown to inhibit osteogenic differentiation of mesenchymal stem cells (MSCs) and bone formation in estrogen-deficiency-induced osteoporosis, but the mechanisms of TNF-α impaired bone formation remain poorly understood. Semaphorins have been shown to regulate cell growth, cell migration, and cell differentiation in a variety of tissues, including bone tissue. Here, we identified a novel mechanism whereby TNF-α, suppressing Semaphorin3B expression contributes to estrogen-deficiency-induced osteoporosis. In this study, we found that TNF-α could decrease Semaphorin3B expression in osteogenic differentiation of MSCs. Overexpression of Semaphorin3B in MSCs attenuated the inhibitory effects of TNF-α on MSCs proliferation and osteoblastic differentiation. Mechanistically, activation of the Wnt/β-catenin signaling markedly rescued TNF-α-inhibited Semaphorin3B expression, suggesting that Wnt/β-catenin signaling was involved in the regulation of Semaphorin3B expression by TNF-α. Taken together, our results revealed a novel function for Semaphorin3B and suggested that suppressed Semaphorin3B may contribute to impaired bone formation by elevated TNF-α in estrogen-deficiency-induced osteoporosis. This study may indicate a therapeutic target gene of Semaphorin3B for osteoporosis.

Tumor necrosis factor α suppresses the mesenchymal stem cell osteogenesis promoter miR-21 in estrogen deficiency-induced osteoporosis

Inflammatory cytokines, especially tumor necrosis factor α (TNF-α), have been shown to inhibit osteogenic differentiation of mesenchymal stem cells (MSCs) and bone formation in estrogen deficiency-induced osteoporosis, but the mechanism responsible remains poorly understood. MicroRNAs (miRNAs) have been shown to regulate MSC differentiation. Here, we identified a novel mechanism whereby TNF-α, suppressing the functional axis of a key miRNA (miR-21) contributes to estrogen deficiency-induced osteoporosis. In this study, we screened differentially expressed miRNAs in MSCs derived from estrogen deficiency-induced osteoporosis and found miR-21 was significantly downregulated. miR-21 was suppressed by TNF-α during the osteogenesis of MSCs. Furthermore, miR-21 was confirmed to promote the osteoblast differentiation of MSCs by repressing Spry1, which can negatively regulate the osteogenic differentiation of MSCs. Upregulating miR-21 partially rescued TNF-α-impaired osteogenesis of MSCs. Blocking TNF-α ameliorated the inflammatory environment and significantly enhanced bone formation with increased miR-21 expression and suppressed Spry1 expression in ovariectomized (OVX) mice. Our results revealed a novel function for miR-21 and suggested that suppressed miR-21 may contribute to impaired bone formation by elevated TNF-α in estrogen deficiency-induced osteoporosis. This study may indicate a molecular basis for novel therapeutic strategies against osteoporosis and other inflammatory bone diseases.

"Twice-a-month" clodronate 200 mg IM: a new dosing regimen and improved therapy adherence in the treatment of postmenopausal osteoporosis

INTRODUCTION

The identification of therapeutic strategies aimed both at preventing and treating osteoporosis and osteoporotic fractures has become increasingly important; in particular, it is essential to promote adequate patient adherence to treatment. The primary aim of this study was to evaluate the effects on lumbar and femoral bone mass density (BMD) after two different intramuscular (IM) dosing regimens of clodronate (CLD), a bisphosphonate shown to be efficacious in reducing the incidence of both vertebral and nonvertebral fractures. Secondary aims were the assessments of bone resorption markers, safety, tolerability, pain, and patient compliance.

METHODS

Sixty women with postmenopausal osteoporosis were randomized to two groups: group A (CLD 100 mg IM weekly for 12 months), and group B (CLD 200 mg IM every 2 weeks for 12 months). All patients received 1 g of calcium supplemented with 800 IU vitamin D(3), orally, once daily for 12 months Lumbar and femoral BMD, measured by DEXA Norland XR-36 (Norland Co., Fort Atkinson, WI), and bone turnover markers were assessed at baseline and at 12 months. Each patient was administered a visual analog scale of pain at baseline and after 6 and 12 months of treatment.

RESULTS

A significant increase of BMD in both groups and in both skeletal sites was observed at 12 months versus baseline. In group A (n=28), lumbar BMD increased by 3.5% and femoral BMD by 2.1%; in group B (n=32), lumbar and femoral BMD rose by 3.4% and 2.2%, respectively. No difference was observed between groups. Bone resorption markers significantly reduced from baseline. Pain significantly improved as early as after 6 months of therapy and even more after 12 months, although no significant difference between the two groups was observed. The most common side effect was pain at the injection site, particularly in group B. Six patients in group A discontinued treatment and failed adherence to the therapeutic protocol. Conversely, no patient from group B discontinued therapy.

CONCLUSION

In agreement with published data, in our two groups of patients, therapy with IM CLD at the doses of 100 mg/week and 200 mg/2 weeks was shown to be effective in increasing BMD, without differences between the two dosing regimens in all assessed efficacy parameters. Therefore, the "twice-a-month" regimen with 200 mg IM CLD may well promote an improved adherence with the same clinical efficacy and safety profile.

A claims database analysis of persistence with alendronate therapy and fracture risk in post-menopausal women with osteoporosis

OBJECTIVE

To explore the relationship between persistence with alendronate therapy and fracture rates in women with postmenopausal osteoporosis.

RESEARCH DESIGN AND METHODS

Claims data from a large US health plan database were used to examine persistence with therapy in postmenopausal women followed for 24 months. Persistence was defined as the time (in days) from the date of first fill to the run-out date of the last prescription with no lapses > 30 days after completion of the previous refill. A persistent cohort (length of persistence > or = 182 days) and a nonpersistent cohort (length of persistence < 182 days) were defined. The number of patients with a fracture claim in each cohort was determined. Cox-proportional hazards regression (HR) analysis was used to determine significant differences in fracture rates between the two cohorts.

RESULTS

4769 patients were followed for 24 months. Patients in the persistent cohort were significantly more likely to receive a treatment (vs. prevention) dose of alendronate (p = 0.03) and to be older than 65 years (p = 0.04). There was a trend toward more fractures in the non-persistent (4.9%) than in the persistent cohort (3.9%; p = 0.09). When controlled for other significant factors (including age and previous fractures) patients in the persistent cohort were 26% less likely to have a fracture diagnosis claim during the study period than those in the non-persistent cohort (HR = 0.74; 95% CI, 0.549-0.996; p = 0.045). Prescription fill data are an indirect measure of medication-taking behavior. The use of claims data to estimate persistence and identify fracture events prohibits the establishment of causality between these two variables.

CONCLUSION

Study results demonstrated that non-persistence with therapy, along with previous fracture and increasing age, was associated with a greater risk of fracture.

Ibandronate: the evolution of a once-a-month oral therapy for postmenopausal osteoporosis

Bisphosphonates have been shown to be highly effective in preventing and treating postmenopausal osteoporosis (PMO) and the associated risk of fracture. However, poor adherence with bisphosphonate therapies for PMO results in a high incidence of otherwise preventable fractures. The chronicity of this condition requires long-term treatment, but fewer than one in two women remains on daily bisphosphonate therapy for 1 yr. A good way to reduce the risk of osteoporotic fractures is through development of equally efficacious formulations with more convenient dosing regimens. Weekly formulations of bisphosphonates have been introduced that demonstrate comparable efficacy to daily formulations with slightly improved adherence. Recently, a new formulation utilizing a third-generation nitrogen-containing bisphosphonate--ibandronate--has been approved with a monthly dosing regimen. The pharmacokinetics and high potency of ibandronate, similar with other bisphosphonates, facilitate lower mg doses and longer-interval dosing frequencies with similar efficacy and enhanced tolerability. Preclinical studies and clinical trials have consistently demonstrated that it is the total cumulative dose of ibandronate that determines efficacy. The convenience of once-monthly dosing may ultimately improve adherence and clinical outcomes among the growing population of postmenopausal women at risk of osteoporosis.

Failure to treat osteoporosis and the risk of subsequent fractures in elderly patients with previous hip fracture: a five-year retrospective study

BACKGROUND AND AIMS

Considering the results of cost-effective analyses, the National Osteoporosis Foundation recommends osteoporosis treatment for patients with previous hip fracture. The aim of this study was to examine the application of adequate treatment for osteoporosis among patients who have had a hip fracture. We also evaluated the rate of subsequent fractures after five years.

METHODS

We conducted a retrospective data study, with a follow-up at five years after discharge, in a tertiary teaching hospital with orthopedic services and all medical specialities. Treatment for osteoporosis and subsequent fracture rates were evaluated in 114 patients with hip fracture. Functional status was assessed using the Barthel Index (BI). We also evaluated the rate of subsequent fractures after five years.

RESULTS

Twenty-five patients (22%) had a new fracture at some moment during the follow-up. Six percent at discharge and 12% at five years of follow-up were receiving adequate treatment for osteoporosis. After five years of follow-up, a decline in their BI persisted in 72% of the 43 surviving patients.

CONCLUSIONS

Few patients were receiving adequate treatment for osteoporosis after hip fracture. Their fracture rates and functional decline were important.

Effects of neridronate treatment in elderly women with osteoporosis

Osteoporosis is a common disorder, especially among elderly post-menopausal women. Elderly women are often affected by co-morbidities, impaired gastrointestinal function and reduced mobility; therefore, the treatment strategy for their osteoporosis can be difficult. In this randomized pilot study, we have investigated the effects of a 12-month treatment with neridronate on bone mineral density (BMD), bone turnover markers and quality of life (QoL). The study included 40 women (age, 65-80 yr; post-menopausal period, >15yr) from a single osteoporosis centre. Twenty women received a monthly im injection of 25 mg of neridronate associated with a daily dose of 500 mg of calcium and 400 U of vitamin D. Twenty women received calcium plus vitamin D supplements alone. Changes in BMD at the lumbar spine and femoral neck were measured by dual energy X-ray absorptiometry. Serum type I collagen C-telopeptide (sCTX), urinary free-deoxypyridinoline (ufDPD), bone alkaline phosphatase (ALP) and serum osteocalcin levels were determined. For the QoL assessment, the Italian version of the SF-36 test was administrated. Spine and hip BMD rose by 6.6 +/- 3 and 4.2 +/- 2.3%, respectively (p < 0.05), after 12 months of neridronate treatment. Markers of skeletal turnover significantly fell already after 3 months of neridronate treatment and decreased progressively thereafter within 12 months. The mean decrease at 12 months ranged from 38 +/- 11% for sCTX to 25.2 +/- 15% for ufDPD (p < 0.001, all). The mean improvement in QoL in the treated group was 45.7% for bodily pain, 37.5% for general health perception, 23.1% for vitality, 18% for emotional role functioning and 12% for physical role functioning. The changes observed in BMD, turnover markers and QoL in the untreated group were ns. The intermittent neridronate administration was easily manageable and well tolerated. In conclusion, neridronate currently represents a valid option for the treatment of osteoporosis, since it helps just as much as oral BPs in the improvement of BMD and in particular conditions it can be even more effective.