Association between refill compliance to oral bisphosphonate treatment, incident fractures, and health care costs--an analysis using national health databases

SUMMARY

The study estimates the cost of poor and suboptimal refill compliance by estimating fracture costs and assessing the association between refill compliance with oral bisphosphonates and incident fractures using Danish health registers. Patients with poor and suboptimal refill compliance had more major osteoporotic fractures, and the direct costs related to hospital care, primary care, and pharmaceutical treatment for these excess fractures reached almost 14 M DKK (2.5 M USD) for the study population which compares to a national annual excess cost of around 17 M DKK (3.1 M USD) using 2011 prescription prevalence.

INTRODUCTION

Adherence to oral anti-osteoporosis treatment has been shown in several studies to be relatively low and the potential impact on fracture burden is high. The aim of the study was to assess the association between refill compliance and all-cause health care costs.

METHODS

A national dataset was extracted with all treatment-naive patients who began oral bisphosphonate (BP) treatment for osteoporosis in Denmark between 1997 and 2006 (N = 54,876, 87 % women). Patients who survived for at least 2 years (N = 47,176) were divided into groups based on Medication Possession Ratio (MPR). Logistic regressions were used to derive difference in the probability of incident fractures between the three MPR groups. Fracture costs (related to medication use, primary care practice, specialists, and hospitals) were derived by comparing cost 12 months before and after fracture.

RESULTS

For alendronate, the adjusted risk of major osteoporotic fractures was significantly reduced (OR 0.768; 0.686-0.859), including fractures of the hip (0.718; 0.609-0.846) and humerus (0.54; 0.431-0.677) with MPR ≥ 0.8. The risk reduction was lower with etidronate. Over 2 years, a total of 171 hip fractures and 53 other major osteoporotic fractures were attributed to suboptimal or poor refill compliance, with an excess cost of 13.7 M DKK (2.5 M USD).

CONCLUSIONS

Poor refill compliance is not unusual in patients on oral bisphosphonates, and we demonstrate that this is accompanied by excess major osteoporotic fractures and health care costs at the societal level.

Cost effectiveness of denosumab versus oral bisphosphonates for postmenopausal osteoporosis in the US

BACKGROUND

In the US, 26 % of women aged ≥65 years, and over 50 % of women aged ≥85 years are affected with postmenopausal osteoporosis (PMO). Each year, the total direct health care costs are estimated to be $US12-18 billion.

OBJECTIVE

The cost effectiveness of denosumab versus oral bisphosphonates in postmenopausal osteoporotic women from a US third-party payer perspective was evaluated.

METHODS

A lifetime cohort Markov model was developed with seven health states: 'well', hip fracture, vertebral fracture, 'other' osteoporotic fracture, post-hip fracture, post-vertebral fracture, and dead. During each cycle, patients could have a fracture, remain healthy, remain in a post-fracture state or die. Relative fracture risk reductions, background fracture risks, mortality rates, treatment-specific persistence rate, utilities, and medical and drug costs were derived using published sources. Expected costs and quality-adjusted life years (QALYs) were estimated for generic alendronate, denosumab, branded risedronate, and branded ibandronate in the overall PMO population and high-risk subgroups: (a) ≥2 of the following risks: >70 years of age, bone mineral density (BMD) T score less than or equal to -3.0, and prevalent vertebral fracture; and (b) ≥75 years of age. Costs and QALYs were discounted at 3 % annually, and all costs were inflated to 2012 US dollars. Sensitivity analyses were conducted by varying parameters e.g., efficacies of interventions, costs, utilities, and the medication persistence ratio.

RESULTS

In the overall PMO population, total lifetime costs for alendronate, denosumab, risedronate, and ibandronate were $US64,400, $US67,400, $US67,600 and $US69,200, respectively. Total QALYs were 8.2804, 8.3155, 8.2735 and 8.2691, respectively. The incremental cost-effectiveness ratio (ICER) for denosumab versus generic alendronate was $US85,100/QALY. Risedronate and ibandronate were dominated by denosumab. In the high-risk subgroup (a), total costs for alendronate, denosumab, risedronate and ibandronate were $US70,400, $US70,800, $US74,000 and $US76,900, respectively. Total QALYs were 7.2006, 7.2497, 7.1969 and 7.1841, respectively. Denosumab had an ICER of $US7,900/QALY versus generic alendronate and dominated all other strategies. Denosumab dominated all strategies in women aged ≥75 years. Base-case results between denosumab and generic alendronate were most sensitive to the relative risk of hip fracture for both drugs and the cost of denosumab.

CONCLUSION

In each PMO population examined, denosumab represented good value for money compared with branded bisphosphonates. Furthermore, denosumab was either cost effective or dominant compared with generic alendronate in the high-risk subgroups.

Comparison of non-vertebral fracture between minodronate and risedronate therapy in elderly female patients with Alzheimer disease

OBJECTIVES

Minodronate is a nitrogen-containing bisphosphonate that is commercially available for the treatment of osteoporosis in Japan. Preclinical studies demonstrated that minodronate is at least 10 times more potent than alendronate in inhibiting bone resorption in vivo. A high incidence of fractures, particularly of the hip, represents an important problem in Alzheimer disease (AD) patients who are prone to falls and may have osteoporosis.

METHODS

A total of 256 elderly patients with AD were assigned to daily treatment with 1.0 mg of minodronate or a daily treatment with risedronate combined with daily 1000 IU ergocalciferol and 1200 mg elemental calcium, and followed up for 12 months.

RESULTS

At baseline, patients of both groups showed low 25-hydroxyvitamin D with compensatory hyperparathyroidism. Non-vertebral fractures occurred in 5 patients in the minodronate group and 7 patients in the risedronate group (5 hip fractures; one fracture each at the distal forearm and pelvis). There was no difference in risk of hip fracture between the two groups (p=.70; odds ratio=0.8).

CONCLUSIONS

The study medications were well tolerated with relatively few adverse events and were equivalent in reducing the risk of a fracture in elderly patients with AD.

Persistence with osteoporosis medication among newly-treated osteoporotic patients

Low persistence with osteoporosis medication is associated with higher fracture risk. Previous studies estimated that 1-year persistence with osteoporosis medication is low. Our aim was to study persistence with osteoporosis medication among patients with long-term follow-up (to 5 years). The InterAction Database (IADB) was used to analyze persistence of 8610 Dutch patients initiating osteoporosis drugs between 2003 and 2011. Drugs under study were alendronate, risedronate, ibandronate, etidronate, raloxifene and strontium ranelate. Cumulative persistence rates were calculated after different time frames (3 months-5 years) using survival analysis. Multivariate Cox proportional hazard analyses were used to identify determinants of non-persistence. Furthermore, switching rates of persistent patients who initiated bisphosphonate therapy were analyzed. Persistence with osteoporosis therapy was 70.7 % (95 % CI, 69.7-71.7), 58.5 % (95 % CI, 57.4-59.6 %), 25.3 % (95 % CI, 24.1-26.5) after 6 months, 1 and 5 years, respectively. Determinants associated with higher risk to non-persistence within the first year were daily dosing regimen [HR, 1.76 (95 % CI, 1.46-2.14)], age <60 years [HR, 1.26 (95 % CI, 1.19-1.34)] and use of glucocorticoids [HR, 1.16 (95 % CI, 1.07-1.26)]. Monthly dosing schedule and use of generic brands of alendronate did not show a significant association with non-persistence. Approximately 4.0 % of patients initiating therapy with weekly alendronate or weekly risedronate switched therapy. Persistence with osteoporosis medication is low. Because low persistence is strongly associated with higher fracture risk, interventions to improve persistence are recommended. This study identified several patient groups in whom such interventions may be most relevant.

Bisphosphonates in the adjuvant setting of breast cancer therapy--effect on survival: a systematic review and meta-analysis

Background

The role of bisphosphonates (BP) in early breast cancer (BC) has been considered controversial. We performed a meta-analysis of all randomized controlled trials (RCTs) that appraised the effects of BP on survival in early BC.

Methods

RCTs were identified by searching the Cochrane Library, MEDLINE databases and conference proceedings. Hazard ratios (HRs) of overall survival (OS), disease-free survival (DFS) and relative risks of adverse events were estimated and pooled.

Results

Thirteen trials met the inclusion criteria, evaluating a total of 15,762 patients. Meta-analysis of ten trials which reported OS revealed no statistically significant benefit in OS for BP (HR 0.89, 95% CI = 0.79 to 1.01). Meta-analysis of nine trials which reported the DFS revealed no benefit in DFS (HR 0.95 (0.81–1.12)). Meta-analysis upon menopausal status showed a statistically significant better DFS in the BP-treated patients (HR 0.81(0.69–0.95)). In meta-regression, chemotherapy was negatively associated with HR of survival.

Conclusions

Our meta-analysis indicates a positive effect for adjuvant BP on survival only in postmenopausal patients. Meta-regression demonstrated a negative association between chemotherapy use BP effect on survival. Further large scale RCTs are warranted to unravel the specific subgroups that would benefit from the addition of BP in the adjuvant setting.

Effectiveness of risedronate and alendronate on nonvertebral fractures: an observational study through 2 years of therapy

This observational study showed that after 2 years, both risedronate and alendronate lowered the risk of hip and nonvertebral fractures compared with patients filling in a single bisphosphonate prescription.

INTRODUCTION

Post hoc analyses of the placebo-controlled trials suggested earlier effects for risedronate (6-12 months) than for alendronate (18-24 months). The present study extends our 1-year observational data that confirmed an earlier fracture reduction with risedronate and evaluated the absolute and relative effectiveness of alendronate and risedronate in clinical practice over 2 years.

METHODS

We observed three cohorts of women aged 65 years and older who initiated once-a-week dosing of bisphosphonate therapy; (1) patients adherent to alendronate (n = 21,615), (2) patients adherent to risedronate (n = 12,215), or (3) patients filling only a single bisphosphonate prescription (n = 5,390) as a referent population. Proportional hazard modeling compared the incidence of hip and nonvertebral fractures among the cohorts over 2 years after the initial prescription.

RESULTS

In this cohort, we previously showed at 12 months a significant reduction of hip and nonvertebral fractures with risedronate but not with alendronate. At the end of 2 years, the cumulative incidence of hip fractures in the referent cohort was 1.9 %, and incidence of nonvertebral fractures was 6.3 %. Relative to the referent, 6 months after initiating therapy and continuing through 2 years, both risedronate and alendronate cohorts had approximately a 45 % lower incidence of hip fractures and a 30 % lower incidence of nonvertebral fractures.

CONCLUSION

These observations suggest that both risedronate and alendronate are effective at reducing the risk of hip and nonvertebral fracture after 2 years of treatment and support the post hoc analyses of placebo-controlled trials indicating an earlier effect of risedronate.

Bisphosphonate-related osteonecrosis of the jaws: a potential alternative to drug holidays

In 2011, the American Dental Association Council on Scientific Affairs released an update by their expert panel on managing the care of patients receiving antiresorptive therapy for the prevention and treatment of osteoporosis. In this report, the panel found no study results that confirmed the effectiveness of drug holidays to prevent antiresorptive agent-induced osteonecrosis of the jaws without increasing the risks of low bone mass. The purpose of this article is to provide suggestions for a pattern of patient care for individuals who desire or require an invasive surgical procedure of the jaws, but who also have a skeleton that is at risk for osteoporotic fracture. The authors reviewed pertinent literature related to basic bone histology, the pharmacokinetics of the aminobisphosphonates (nBP), diagnostic criteria for osteopenia/osteoporosis, and clinical applications of the antiresorptive agents. The skeletal system demonstrates a mixture of resting surfaces (osteocytes, 85%), resorbing surfaces (osteoclasts, 2%), and forming surfaces (osteoblasts, 10%-12%). Deposition of nBP is not uniform, and is highly concentrated in areas of bone remodeling. A full understanding of bone remodeling and the pharmacokinetics of nBP allow for the modification of the antiresorptive therapy and the timing of the oral surgical procedure in a manner that minimizes the prevalence of osteonecrosis while at the same time continuing to protect the patient's skeleton from osteoporotic fracture. The lack of support for drug holidays by the ADA's expert panel is strongly consistent with the science behind bone remodeling and nBP pharmacokinetics. In spite of this, creative interdisciplinary patient care has the potential to dramatically reduce the prevalence of bisphosphonate-related osteonecrosis (BRON), while at the same time continuing to protect the skeleton of the osteoporotic patient. Creative interdisciplinary patient care may prove to be an effective intervention to reduce the prevalence of BRON of the jaws.

Atorvastatin, etidronate, or both in patients at high risk for atherosclerotic aortic plaques: a randomized, controlled trial

BACKGROUND

Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta.

METHODS AND RESULTS

A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, -16.4 to -11.3) and 12.3% (95% confidence interval, -14.9 to -9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, -0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (-11.4%) than in the atorvastatin group (-0.9%; P<0.001) and the etidronate group (5.5%; P=0.006).

CONCLUSIONS

Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.

Intervention thresholds for denosumab in the UK using a FRAX®-based cost-effectiveness analysis

The objective was to undertake a health economic analysis of denosumab for the treatment of osteoporosis in women from the UK, using the FRAX® tool. Denosumab was cost-effective in women with a risk of major osteoporotic fracture meeting or exceeding approximately 20% who are unable to take, comply with or tolerate generic alendronate.

INTRODUCTION

Denosumab is a novel biologic agent developed for the treatment of osteoporosis, which has been shown to reduce the risk of fractures in a phase-III trial. The objective of the present study was to undertake a health economic analysis of denosumab in women from the UK. Ten-year probabilities of a major osteoporotic fracture at which denosumab is a cost-effective alternative to no treatment, generic alendronate, risedronate and strontium ranelate were estimated.

METHODS

A previously published Markov model was adapted to incorporate fracture and mortality risk assessments based on absolute fracture probability, as estimated by FRAX®. The model included treatment persistence and residual effect after discontinuation.

RESULTS

At a willingness-to-pay (WTP) of £30,000 per quality-adjusted life year and a 10-year fracture probability equivalent to a woman with a prior fragility fracture, denosumab was cost-effective compared to no treatment from the age of 70 years. At the same WTP, denosumab was-irrespective of age-cost-effective compared to no treatment at a major osteoporotic fracture probability of approximately 20%. Denosumab was estimated to cost-effectively replace strontium, risedronate and generic alendronate at 10-year probabilities exceeding 11, 19 and 32%, respectively.

CONCLUSION

FRAX® facilitates the estimation of cost-effectiveness-based intervention thresholds applicable to patients with different combinations of clinical risk factors, which more closely matches the situation in clinical practice. Denosumab is cost-effective in patients with major osteoporotic fracture probabilities meeting or exceeding approximately 20% who are unable to take, comply with or tolerate generic alendronate.

The effects of risedronate administered in combination with a proton pump inhibitor for the treatment of osteoporosis

This study was performed to investigate the effects of the co-administration of proton pump inhibitor (PPI) on the efficacy of bisphosphonate (BP) treatment for osteoporosis. A total of 180 women with low bone mineral density were randomly divided into four groups, one in which sodium risedronate was administered with sodium rabeprazole and one in which only risedronate was administered (BP + PPI and BP groups, respectively). The biomarkers were measured at the baseline and every 3 months, inlcuding: N-terminal telopeptide of type I collagen corrected for creatinine, bone-specific alkaline phosphatase (BAP), parathyroid hormone, bone mineral density (BMD) of the lumbar spine and physical parameters evaluated according to the SF-36v2™ Health Survey. Statistical comparisons of these parameters were performed after 9 months. Data were available for a total of 137 patients (62 in the BP group and 75 in the BP + PPI group). The Δ % value of increase in BMD and improvement of physical functioning in the BP + PPI group were significantly larger, and its decrease in BAP in the BP + PPI group was significantly smaller than that in the BP group. It is expected that risedronate administration in combination with a PPI may be more effective not only for treating osteoporosis but also improving physical fitness than treatment with risedronate alone.

[Establishment of zebrafish osteopenia model induced by dexamethasone]

Zebrafish was selected as model animal, and glucocorticoid dexamethasone was used as a model compound to establish a rapid and high efficient osteopenia model. Zebrafish larvae at 4 days post fertilization (dpf) were exposed to a serial concentrations of dexamethasone solutions, and 0.5% DMSO was selected as the vehicle control group. All groups were incubated in 24-well plates (28.5 degrees C) until 9 dpf. In addition, effects of 10 micromol x L(-1) dexamethasone on preventing against osteopenia induced by etidronate disodium were also investigated. Zebrafish bones at 9 dpf were stained with alizarin red. Quantitative analysis of the stained area was performed by microscopic inspection and digital imaging methods to reflect the amount of bone mineralization. Results showed that dexamethasone group at 2.5, 10 and 25 micromol x L(-1) can decrease the staining area and the staining optical density values of zebrafish head bones when compared with the vehicle control group (0.5% DMSO), which suggested that dexamethasone can significantly reduce the zebrafish mineralized bone and the bone mineral density. Results also showed that 15 and 30 microg x mL(-1) etidronate disodium can increase the mineralized matrix of zebrafish head bone and prevent against osteopenia induced by dexamethasone. In conclusion, the study indicated that zebrafish can be an idea osteopenia model induced by dexamethasone.

Oral bisphosphonates reduce the risk of clinical fractures in glucocorticoid-induced osteoporosis in clinical practice

This study aims to estimate bisphosphonate effectiveness by comparing fracture incidence over time on therapy in glucocorticoid-induced osteoporosis (GIO). From this observational study, alendronate and risedronate decreased clinical vertebral and nonvertebral fractures over time. The effectiveness of each bisphosphonate is consistent with their efficacies demonstrated on surrogate markers in randomized controlled trials (RCTs).

INTRODUCTION

This study aims to estimate bisphosphonate effectiveness by comparing fracture incidence over time on therapy with fracture incidence during a short period after starting a therapy.

METHODS

The study population was a subgroup of a larger cohort study comprising two cohorts of women aged ≥65 years, prescribed with alendronate or risedronate. Within the two study cohorts, 11,007 women were identified as having received glucocorticoids. Within each cohort, the baseline incidence of clinical fractures at nonvertebral and vertebral sites was defined by the initial 3-month period after starting therapy. Relative to these baseline data, we then compared the fracture incidence during the subsequent 12 months on therapy.

RESULTS

The baseline incidence of clinical nonvertebral and vertebral fractures was similar in the alendronate cohort (5.22 and 5.79/100 person-years, respectively) and in the risedronate cohort (5.51 and 5.68/100 person-years, respectively). Relative to the baseline incidence, fracture incidence was significantly lower in the subsequent 12 months in both cohorts of alendronate (33 % lower at nonvertebral sites and 59 % at vertebral sites) and risedronate (28 % lower at nonvertebral sites and 54 % at vertebral sites).

CONCLUSION

From this observational study not designed to compare drugs, both alendronate and risedronate decreased clinical vertebral and nonvertebral fractures over time. The reductions observed in fracture incidence, within each cohort, suggest that the effectiveness of each bisphosphonate in clinical practice is consistent with their efficacies demonstrated on surrogate markers in randomized controlled trials.

Treatment of postmenopausal osteoporosis with delayed-release risedronate 35 mg weekly for 2 years

Bone mineral density response to once weekly delayed-release formulation of risedronate, given before or following breakfast, was non-inferior to that seen with traditional immediate-release risedronate given daily before breakfast. Delayed-release risedronate is a convenient dosing regimen for oral bisphosphonate therapy that might avoid poor compliance.

INTRODUCTION

This 2-year, randomized, controlled, non-inferiority study assessed the efficacy and safety of a delayed-release (DR) 35-mg weekly oral formulation of risedronate that allows subjects to take their weekly risedronate dose before or immediately after breakfast. Results from the first year of the study were published previously (McClung et al. Osteoporos Int 23(1):267-276, 2012); we now report the final results after 2 years.

METHODS

Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg immediate-release (IR) daily (n = 307) at least 30 min before breakfast, or risedronate 35 mg DR weekly, either immediately following breakfast (FB, n = 307) or at least 30 min before breakfast (BB, n = 308). Bone mineral density (BMD), bone turnover markers (BTMs), fractures, adverse events, and bone histomorphometry were evaluated.

RESULTS

A total of 248 subjects (80.8 %) in the IR daily group, 234 subjects (76.2 %) in the DR FB weekly group, and 240 subjects (77.9 %) in the DR BB weekly group completed the 2-year study. After 2 years of treatment, BMD increases at the lumbar spine and total hip with the weekly DR doses similar to or greater than that with the IR daily dose. Decreases in BTMs were similar or significantly lower in the DR groups. Bone histomorphometry results did not differ among the DR weekly and the IR daily formulations. The three regimens were similarly well tolerated.

CONCLUSIONS

Risedronate 35 mg DR weekly is as effective and as well tolerated as risedronate 5 mg IR daily, and will allow subjects to take their weekly risedronate dose immediately after breakfast.

Efficacy and safety of risedronate 150-mg once a month in the treatment of postmenopausal osteoporosis: 2-year data

This study showed that risedronate 150-mg once a month provides similar efficacy and safety at 2 years compared with risedronate 5-mg daily for the treatment of postmenopausal osteoporosis. This adds to the range of risedronate dosing options and provides an alternative for patients who prefer once-a-month dosing.

INTRODUCTION

Risedronate is effective in the treatment of postmenopausal osteoporosis in oral daily, weekly, or on two consecutive days per month doses. This 2-year randomized, double-blind, multicenter study assesses the efficacy and safety of a single risedronate 150-mg once-a-month oral dose compared with the 5-mg daily regimen.

METHODS

Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5-mg daily (n = 642) or 150-mg once a month (n = 650) for 2 years. Bone mineral density (BMD), bone turnover markers, new vertebral fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine BMD after 1 year.

RESULTS

Four hundred ninety-eight subjects in the daily group (77.6 %) and 513 subjects in the once-a-month group (78.9 %) completed the study. After 24 months, the mean percent change in lumbar spine BMD was 3.9 % (95 % confidence interval [CI], 3.43 to 4.42 %) and 4.2 % (95 % CI, 3.68 to 4.65 %) in the daily and once-a-month groups, respectively. The once-a-month regimen was determined to be non-inferior to the daily regimen. The mean percent changes in BMD at the hip were similar in both dose groups, as were changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the two treatment groups.

CONCLUSIONS

After 2 years, treatment with risedronate 150-mg once a month provided similar efficacy and tolerability to daily dosing and provides an alternative for patients who prefer once-a-month oral dosing.

A meta-analysis characterizing the dose-response relationships for three oral nitrogen-containing bisphosphonates in postmenopausal women

A meta-analysis of spine BMD dose-response relationships for alendronate, risedronate, and ibandronate was performed. Data from all three oral bisphosphonates conform to a log-linear relationship between dose and change in spine BMD relative to placebo at 1 year, with an incremental gain of about 1 % for each doubling of dose.

INTRODUCTION

Animal data suggesting differences in potency and differences in approved oral dosage strengths for alendronate, risedronate, and ibandronate in the treatment of osteoporosis raise questions about their dose-response relationships and relative potencies in humans.

METHODS

A meta-analysis of dose-response relationships for spine BMD increases for these three bisphosphonates was performed using data from 21 placebo-controlled trials that collectively included over 13,000 patients on active treatment and over 8,000 on placebo.

RESULTS

For alendronate over the range of 1 to 20 mg/day, there was a strong log-linear relationship between dose and the increase in spine BMD relative to placebo at 1 year (R (2) = 0.994 using sample-weighted means). For each doubling in alendronate dose, there was an incremental gain of about 1 % in spine BMD. On the same scale, risedronate and ibandronate are approximately equipotent to alendronate on a weight-for-weight basis. The increases in BMD efficacy with each doubling of dose are parallel for all three nitrogen-containing bisphosphonates (NCBPs).

CONCLUSIONS

All three NCBPs are approximately equipotent and exhibit a log-linear relationship between dose and the increase in spine BMD. Differences in efficacy between the available oral bisphosphonate regimens appear to be a function of dose rather than inherent differences in therapeutic potential.

Effects of bisphosphonate treatment on circulating osteogenic endothelial progenitor cells in postmenopausal women

OBJECTIVE

To evaluate whether bisphosphonates modulate vascular calcification by a modification in endothelial progenitor cells (EPCs) coexpressing osteoblastic surface markers and genes.

PATIENTS AND METHODS

We performed a double-blind, randomized study of 20 healthy, early postmenopausal women (from February 1, 2008, through July 31, 2008) treated with placebo or risedronate sodium (35 mg/wk) for 4 months. Peripheral blood was collected at baseline and 4 months to determine serum inflammatory markers, osteoprotegerin, and receptor activator of nuclear factor-κB ligand levels and bone turnover markers. Peripheral blood mononuclear cells were stained for EPC surface markers (CD34, CD133, and vascular endothelial growth factor receptor/kinase insert domain receptor) and osteoblast markers (osteocalcin, alkaline phosphatase, and Stro-1).

RESULTS

Risedronate treatment resulted in a significant down-regulation of gene sets for osteoblast differentiation and proliferation in EPCs with a trend of decreasing EPCs coexpressing osteocalcin.

CONCLUSION

Our findings indicate that bisphosphonate treatment down-regulates the expression of osteogenic genes in EPCs and suggest a possible mechanism by which bisphosphonates may inhibit vascular calcification.

Incidence of fractures of the femur, including subtrochanteric, up to 8 years since initiation of oral bisphosphonate therapy: a register-based cohort study using the US MarketScan claims databases

In a cohort study of users of bisphosphonates, we evaluated the incidence of fragility fractures at all sites on the femur following for up to 8 years of therapy with alendronate or risedronate. We did not find evidence for a reversal of fracture protection with long-term use of bisphosphonates.

INTRODUCTION

Few studies have acquired adequate data with prolonged follow-up on bisphosphonate users in the general population to evaluate their long-term effects on the risk of hip fractures including those in the subtrochanteric region.

METHODS

This cohort study utilizes a large USA database (January 1, 2000 to June 30, 2009). We compared patients with higher versus lower degrees of compliance [medication possession ratio, MPR <1/3 (the reference), 1/3-<2/3, or ≥ 2/3]. Radiographic adjudication of fracture site and features were not performed. Hazard ratios (HR) for fracture were estimated using time-dependent Cox models. Restricted cubic splines (RCS) were used to plot HRs for fracture against duration of therapy.

RESULTS

There were 3,655 incident cases of femoral fracture (764 subtrochanteric/shaft, 2,769 hip) identified during 917,741 person-years of follow-up (median  =  3 years) on 287,099 patients (267,374 were women) from the date when they initiated oral bisphosphonate therapy. The corresponding HRs (95% confidence interval, CI) for overall femoral fractures associated with each additional year of therapy were 0.93 (0.86-1.01) within 5 years, and 0.89 (0.77-1.03) beyond 5 years for risedronate and 0.86 (0.81-0.91) and 0.95 (0.84-1.07) for alendronate, respectively. The corresponding estimates for subtrochanteric/shaft fractures were 1.05 (0.87-1.26) and 0.89 (0.60-1.33) for risedronate and 0.99 (0.92-1.05) and 1.05 (0.92-1.20) for alendronate, respectively. The HRs (95% CI) for overall femoral fractures associated with each additional year of alendronate or risedronate therapy within 5 and beyond 5 years were not significantly different.

CONCLUSION

Our study showed persistence of overall hip fracture protection with long-term use of alendronate or risedronate.

The effect of risedronate (17.5 mg/week) treatment on quality of life in Japanese women with osteoporosis: a prospective observational study

A prospective observational study to test the effects of risedronate 17.5 mg/week treatment on quality of life (QOL) of 1,363 Japanese female patients with osteoporosis showed QOL improvement after 12 weeks of administration. Comorbid factors such as ischemic heart disease, hip osteoarthritis, and higher values of FRAX blunted the effects of QOL of the treatment. Few studies have investigated the effect of osteoporosis treatment on QOL in relationship to comorbid factors other than osteoporosis and fracture. Efficacy was determined by changes over time in EQ-5D at baseline, at 12 and 24 weeks, and at the final assessment. Factors affecting changes in EQ-5D were evaluated with a multivariate analysis. Safety was determined by assessing the incident rate of adverse events. The improvement of EQ-5D compared to baseline was observed as significant after 12 weeks of treatment (p < 0.001). The greatest improvement was observed in the dimension of "pain/discomfort" by the multivariate analysis (p < 0.001). Factors affecting QOL improvement were FRAX value without BMD, age, glucocorticoid use, ischemic heart disease, hip osteoarthritis, and pain. The incidence rate of drug-related adverse events was 4.72 % (95 % confidence interval 3.63-6.02 %). Risedronate at 17.5 mg/week improved the QOL in patients with osteoporosis among Japanese women, and comorbidity factors decreased the effects.

How rebates, copayments, and administration costs affect the cost-effectiveness of osteoporosis therapies

PURPOSE

Because of rising drug expenditures, cost considerations have become essential, necessitating the requirement for cost-effectiveness analyses for managed care organizations (MCOs). The study objective is to examine the impact of various drug-cost components, in addition to wholesale acquisition cost (WAC), on the cost-effectiveness of osteoporosis therapies.

DESIGN

A Markov model of osteoporosis was used to exemplify different drug cost scenarios.

METHODOLOGY

We examined the effect of varying rebates for oral bisphosphonates--risedronate and ibandronate--as well as considering the impact of varying copayments and administration costs for intravenous zoledronate. The population modeled was 1,000 American women, > or = 50 years with osteoporosis. Patients were followed for 1 year to reflect an annual budget review of formularies by MCOs. The cost of therapy was based on an adjusted WAC, and is referred to as net drug cost. The total annual cost incurred by an MCO for each drug regimen was calculated using the net drug cost and fracture cost. We estimated cost on a quality adjusted life year (QALY) basis.

PRINCIPAL FINDINGS

When considering different rebates, results for risedronate versus ibandronate vary from cost-savings (i.e., costs less and more effective) to approximately $70,000 per QALY. With no risedronate rebate, an ibandronate rebate of approximately 65% is required before cost per QALY surpasses $50,000. With rebates greater than 25% for risedronate, irrespective of ibandronate rebates, results become cost-saving. Results also showed the magnitude of cost savings to the MCO varied by as much as 65% when considering no administration cost and the highest coinsurance rate for zoledronate.

CONCLUSION

Our study showed that cost-effectiveness varies considerably when factors in addition to the WAC are considered. This paper provides recommendations for pharmaceutical manufacturers and MCOs when developing and interpreting such analyses.

Primary lymphoma of the mandible masquerading as bisphosphonate-related osteonecrosis of jaws

A 66-year-old osteoporotic woman suffered from long-term mental paresthesia (numbness), facial swelling, and a nonhealing extraction site. Fulfilling the three clinical diagnostic criteria for bisphosphonate-related osteonecrosis of the jaw (BRONJ; exposed bone for at least 8 weeks, current bisphosphonate [risedronate] treatment, and no history of head and neck radiation therapy), she was diagnosed and treated accordingly. Nevertheless, a later histopathologic examination revealed malignant lymphoproliferative infiltration of large and intermediate cells. Based on immunostaining and positron-emission tomography, she was diagnosed as having primary diffuse large B-cell lymphoma. This case demonstrates the limitation of the current diagnostic method of BRONJ. Thus, the clinician should be particularly cautious and aware of the differential diagnosis, including malignancy, especially when lesions are accompanied by (mental nerve) neuropathy and long-standing swelling/expansion, and even when plain radiography is not a contributing factor.

Osteomalacia in a patient with Paget's bone disease treated with long-term etidronate

A 93 year-old woman with Paget's disease of bone had been treated with etidronate without interruption during 20 years. The daily dose was usual (5mg/kg/day) but this prescription had never been stopped by her physicians. Two fractures had already occurred in pagetic (right tibia) and non pagetic bones (right fibula) within the last 2 years, and she presented rib fractures, another right tibia fracture and right femur fracture during hospitalization time. X-rays films showed major osteolysis of left ulna and right tibia. Blood samples and technetium bone scan brought no evidence for sarcoma or lytic evolution of the disease. A transiliac bone biopsy on non pagetic bone site confirmed the diagnosis of osteomalacia (increased osteoid parameters), with secondary hyperparathyroidism (hook resorption). In Paget's disease of bone, continuous treatment by etidronate may induce generalized osteomalacia, and increase the risk of fracture in both pagetic and non-pagetic bones. Whereas physicians and pharmaceutical industry try to improve the observance of those drugs, this striking observation also points out that a prescription always needs to be updated.

Evidence for safety and efficacy of risedronate in men with osteoporosis over 4 years of treatment: Results from the 2-year, open-label, extension study of a 2-year, randomized, double-blind, placebo-controlled study

A 2-year, randomized, double-blind, placebo-controlled study in men with osteoporosis demonstrated that treatment with risedronate 35mg once a week significantly decreased bone turnover markers (BTMs) and increased bone mineral density (BMD). This study was extended to include a 2-year, open-label extension to continue to assess the safety and efficacy of risedronate in men with osteoporosis. In the open-label extension, all patients received risedronate 35mg once a week, and 1000mg elemental calcium and 400 to 500IU vitamin D daily for up to 2 years. The safety of risedronate was evaluated based on adverse events, laboratory data, vital signs, and physical examination results. BMD, BTMs, and the incidence of new vertebral fractures were also assessed. A total of 218 (of 284) patients enrolled in the open-label extension. Risedronate continued to produce significant increases in lumbar spine BMD from baseline (7.87%) in the group of patients who took it for 4 years. Risedronate produced significant increases in lumbar spine BMD from baseline (6.27%) in the former placebo group who took it for 2 years during the open-label extension. Few new vertebral and clinical fractures occurred during the study. There were no significant differences in BTMs between the two groups at months 36 and 48. Incidences of any upper GI adverse events during the extension were low and similar in the two groups; however, the percent of moderate to severe events were higher (8% versus 2%) in the group that received placebo prior to the extension. Safety results continued to show that risedronate was well-tolerated in men with osteoporosis. Patients who received risedronate 35mg once a week for 2years in the open-label extension study showed similar safety and efficacy results compared with those who received risedronate treatment in the first 2 double-blind years of the study. Patients who received risedronate for 4 years in total showed similar safety and efficacy to that observed in women with postmenopausal osteoporosis treated with risedronate for 4 years. (ClinicalTrials.gov Identifier number: NCT00619957).

Efficacy of intravenously administered ibandronate in postmenopausal Korean women with insufficient response to orally administered bisphosphonates

We investigated rates of insufficient and over-responsiveness to orally administered bisphosphonates in postmenopausal women, and tested the efficacy of intravenous ibandronate in patients with insufficient response to orally administered bisphosphonates. Postmenopausal women were treated with either alendronate (70 mg/week; n = 88) or risedronate (35 mg/week; n = 84) for 1 year, and their response to orally administered bisphosphonates was assessed using serum C-telopeptide (CTX) levels. Insufficient responders were changed to once-quarterly intravenous ibandronate 3 mg injection (n = 13) or maintained on orally administered bisphosphonates (n = 19), according to patients' preference, for an additional 1 year. There was no significant difference in baseline characteristics between two orally administered bisphosphonate groups except the bone mineral density values at the lumbar spine. Insufficient rate was higher in the risedronate group (19.0 %) than in the alendronate group (8.0 %), using the premenopausal serum CTX median as a cut-off (P = 0.043). The over-response rate among the alendronate group (59.1 %) was significantly higher than that in the risedronate group (38.1 %), based on a serum CTX cut-off value of 0.100 ng/ml (P = 0.006). Intravenous ibandronate suppressed serum CTX levels to a significantly greater degree at 7 days after the second dosing (0.191 ± 0.110 ng/mL; P < 0.001) and 3 months after the fourth dosing (0.274 ± 0.159 ng/mL; P = 0.004) among insufficient responders, compared with post-oral/pre-intravenous levels (0.450 ± 0.134 ng/mL). Rates of insufficient and over-responsiveness to orally administered bisphosphonates were considerable, and a change to intravenous bisphosphonates may be considered in patients showing an insufficient response to orally administered bisphosphonates.

The effect of teriparatide compared with risedronate on reduction of back pain in postmenopausal women with osteoporotic vertebral fractures

The effect of teriparatide and risedronate on back pain was tested, and there was no difference in the proportion of patients experiencing a reduction in back pain between groups after 6 or 18 months. Patients receiving teriparatide had greater increases in bone mineral density and had fewer vertebral fractures.

INTRODUCTION

This study aimed to understand the effect of teriparatide in reducing back pain in patients with prevalent back pain and vertebral fracture compared to risedronate.

METHODS

In an 18-month randomized, double-blind, double-dummy trial, we investigated the effects of teriparatide (20 μg/day) vs. risedronate (35 mg/week) in postmenopausal women with back pain likely due to vertebral fracture. The primary objective was to compare the proportion of subjects reporting ≥30% reduction in worst back pain severity from baseline to 6 months as assessed by a numeric rating scale in each treatment group. Pre-specified secondary and exploratory outcomes included assessments of average and worst back pain at additional time points, disability and quality of life, bone mineral density, incidence of fractures, and safety.

RESULTS

At 6 months, 59% of teriparatide and 57% of risedronate patients reported ≥30% reduction in worst back pain and there were no differences between groups in the proportion of patients experiencing reduction in worst or average back pain at any time point, disability, or quality of life. There was a greater increase from baseline in bone mineral density at the lumbar spine (p = 0.001) and femoral neck (p = 0.02) with teriparatide compared to risedronate and a lower incidence of vertebral fractures at 18 months (4% teriparatide and 9% risedronate; p = 0.01). Vertebral fractures were less severe (p = 0.04) in the teriparatide group. There was no difference in the overall incidence of adverse events.

CONCLUSIONS

Although there were no differences in back pain-related endpoints, patients receiving teriparatide had greater skeletal benefit than those receiving risedronate.