Effect of 1 year of discontinuation of raloxifene or estrogen therapy on bone mineral density after 5 years of treatment in healthy postmenopausal women

Treatment Sequence for Osteoporosis

BACKGROUND

Osteoporosis is a chronic progressive disease that requires lifelong monitoring and treatment. Sequencing from one treatment to another at different ages and stages of disease is an approach that can maximize benefits and avoid potential risks from long-term treatment with a single agent.

OBJECTIVE

This article reviews clinical trial data in postmenopausal women that evaluate the effects of antiresorptive agents followed by other antiresorptives, osteoanabolic agents followed by antiresorptives, and antiresorptives followed by osteoanabolic medications.

METHODS

Literature review and discussion.

RESULTS

When medications are discontinued, in the absence of sequential therapy, bone turnover rates return to baseline or above baseline, and bone loss occurs. The rate of bone loss differs for different treatments, with a very slow decline after stopping bisphosphonates and a particularly rapid decline after stopping denosumab. Careful attention to osteoporosis medication transitions can mitigate bone density loss and its consequences. For women who remain at high risk, switching from bisphosphonates to the more potent antiresorptive, denosumab, will result in further improvement in bone mineral density (BMD). When indicated, stopping denosumab can be accomplished safely by transition to an adequate bisphosphonate regimen. For high- and very-high-risk patients, treating with osteoanabolic agents first, followed by antiresorptive agents, produces substantially larger BMD gains than the reverse treatment sequence, with the biggest differences seen for BMD of the hip.

CONCLUSION

Awareness of the importance of treatment sequences can help improve osteoporosis care across the postmenopausal lifespan.

Predictors for self-discontinuation of anti-osteoporosis medication: A hospital-based real-world study

Osteoporotic fractures have a tremendous impact on quality of life and may contribute to fatality, but half of patients may discontinue their anti-osteoporosis medication. The study aimed to investigate the factors associated with the persistence of anti-osteoporosis medication. Between June 2016 and June 2018, we recruited 1195 participants discontinuing prior anti-osteoporosis medication. Telephone interviews were conducted to discern the reasons for discontinuation. Comparisons among groups and risks of self-discontinuation were analyzed. Among 694 patients who have no records of continuing anti-osteoporosis medication, 374 (54%) self-discontinued, 64 (9.2%) discontinued due to physicians’ suggestion, and 256 (36.8%) with unintended discontinuation. Among patients with self-discontinuation, 173 (46.3%) forgot to visit outpatient clinics; 92 (24.5%) discontinued because of medication-related factors; 57 (15.2%) thought the severity of osteoporosis had improved and therefore discontinued; 30 (8%) stopped due to economic burden; 22 (5.9%) were lost to follow-up because of newly diagnosed diseases other than osteoporosis. Additionally, older age, male gender, calcium supplement, teriparatide therapy and hip fractures in teriparatide users were associated with adherence to anti-osteoporosis drugs. In conclusion, our results indicate that younger age, female gender, non-use of calcium supplements, and anti-resorptive medication were independent risk factors associated with drug discontinuation. Identifying high-risk patients and providing timely health education are crucial for adherence to anti-osteoporosis medication.

Osteoporotic Fractures among Selective Estrogen Receptor Modulator Users in South Korea: Analysis Using National Claims Database

Background

We evaluated (1) compliance with selective estrogen receptor modulator (SERM) use in postmenopausal women; and (2) the risk of osteoporotic fractures according to compliance and other patient characteristics.

Methods

National claims data of postmenopausal women from January 2013 to December 2014 were reviewed. Demographics, comorbidities, type of medical institution, and patient compliance were investigated. Compliance was measured according to medication possession ratio (MPR) and the patients were classified into compliant (MPR ≥80%) or non-compliant (MPR <80%) groups. Osteoporotic fractures were followed up for 2 years after prescription.

Results

Among 15,166 postmenopausal women, 4,130 were categorized as compliant. Osteoporotic fractures were confirmed in 669 patients. The hip fracture rate in the non-compliant group (0.39%) was marginally higher than that in the compliant group (0.36%; P=0.06). Compared to age 50 to 54 years, age 55 to 59 years showed protection against fractures (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.379–0.857; P=0.007), while those over 70 years showed a higher risk of fractures (HR, 2.035; 95% CI, 1.485–2.789; P<0.0001 for age 70–74 years; HR, 2.197; 94% CI, 1.588–3.041; P<0.0001 for age 75–79 years; and HR, 3.53; 95% CI, 2.493–4.999; P<0.0001 for age ≥80 years). Patients with mild (HR, 1.29; 95% CI, 1.088–1.530; P=0.0034) and moderate (HR, 1.286; 95% CI, 1.002–1.652; P=0.0486) comorbidities were associated with higher risks of fractures compared to those without comorbidities.

Conclusions

Among postmenopausal women with osteoporosis, only 27.2% complied with SERM therapy. A marginal difference in hip fracture rate was observed between the compliant and non-compliant groups. Older age and severe comorbidities were associated with higher risks of osteoporotic fractures.

Bone Mineral Density Loss and Fracture Risk After Discontinuation of Anti-osteoporotic Drug Treatment: A Narrative Review

The number of patients on long-term anti-osteoporotic drug therapy is rising. Unfortunately, there are few data to guide decisions about duration of pharmacologic therapy for osteoporosis. Many practitioners discontinue therapy after a period of 5 years because of the risk of rare but severe side effects that may occur in long-term users. The objective of this narrative review was to describe the effects of discontinuation of anti-osteoporotic drugs and to investigate what is not yet known on this topic. For each anti-osteoporotic agent, PubMed was searched for evidence from randomized clinical trials in patients with osteoporosis on osteoporotic drugs lasting ≥ 3 years, followed by ≥ 1 year of follow-up after discontinuation of therapy and reported at least one item of the following: changes in bone mineral density, bone turnover markers and/or the risk of vertebral and/or nonvertebral fractures after discontinuation of therapy. The% change in bone mineral density (BMD) after 1 year of discontinuation of therapy is − 0.4% or less at the hip and femoral neck in both alendronate- and zoledronic acid-treated patients. In the other reported agents (risedronate, ibandronate, raloxifene, teriparatide, denosumab and romosozumab) this percentage of bone loss at the femoral neck and total hip was at least 1%, with the largest decrease in BMD after discontinuation of denosumab and romosozumab. In all studies reporting bone turnover markers, a substantial rapid rise in these markers was observed after discontinuation of therapy, with a large rebound increase to far above baseline levels in the denosumab-treated patients. There were few data on fracture risk after discontinuation of therapy; data showed that discontinuing alendronate, zoledronic acid and especially denosumab significantly increases the risk of vertebral fractures. In conclusion, osteoporosis should be considered more as a chronic condition. Therefore, in modern fracture risk management, continuous monitoring and treatment is required, as is the case with other chronic diseases, to sustain the benefits of therapy, especially in denosumab- and romosozumab-treated patients. The exception is alendronate and zoledronic acid, in these patients a discontinuation of drug therapy of 1 year or more might be acceptable.

Insufficient persistence to pharmacotherapy in Japanese patients with osteoporosis: an analysis of the National Database of Health Insurance Claims and Specific Health Checkups in Japan

In Japan, persistence and the 2-year MPR were inadequate in increasing fracture control efficacy despite a high adherence rate during the treatment period. Both factors were higher in females and those with polypharmacy but worsened with increasing age.

PURPOSE

Only a few large-scale studies have examined the care gap between the patients who need osteoporosis treatment and those who receive them in Japan. The aim of this study was to investigate the persistence and adherence to osteoporosis pharmacotherapy in Japan.

METHODS

Continuation (persistence) rates and adherence to osteoporosis pharmacotherapy were investigated using medical insurance data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, between April 2012 and March 2019.

RESULTS

The study included 528,806 male and 3,064,410 female patients. Persistence proportions were 56.6% in the first year and 46.3% in the second year. The medication possession ratio (MPR) from start to discontinuation of treatment (MPR_discon) was 94.5%, and 92.7% of patients had an MPR_discon ≥ 80%. The 2-year MPR (MPR₇₃₀) was 61.9%, and 49.6% of patients had an MPR₇₃₀ ≥ 80%. Both the persistence proportion and MPR₇₃₀ were higher in females than in males, whereas MPR_discon was higher in males. The persistence proportion and MPR₇₃₀ were highest in the 70-79 years age group, whereas MPR_discon improved with increasing age. The MPR_discon and MPR₇₃₀ were higher in the mixed-fracture and vertebral-fracture groups, respectively. The persistence proportion, MPR_discon, and MPR₇₃₀ were higher in patients with polypharmacy than in those without.

CONCLUSION

In Japan, persistence and the 2-year MPR were inadequate in increasing fracture control efficacy despite a high adherence rate during the treatment period. To bridge the care gap following osteoporosis pharmacotherapy, improvements are required for males, the elderly, and those without polypharmacy.

Management of osteoporosis in postmenopausal women: the 2021 position statement of The North American Menopause Society

OBJECTIVE

To review evidence regarding osteoporosis screening, prevention, diagnosis, and management in the past decade and update the position statement published by The North American Menopause Society (NAMS) in 2010 regarding the management of osteoporosis in postmenopausal women as new therapies and paradigms have become available.

DESIGN

NAMS enlisted a panel of clinician experts in the field of metabolic bone diseases and/or women's health to review and update the 2010 NAMS position statement and recommendations on the basis of new evidence and clinical judgement. The panel's recommendations were reviewed and approved by the NAMS Board of Trustees.

RESULTS

Osteoporosis, especially prevalent in older postmenopausal women, increases the risk of fractures that can be associated with significant morbidity and mortality. Postmenopausal bone loss, related to estrogen deficiency, is the primary contributor to osteoporosis. Other important risk factors for postmenopausal osteoporosis include advanced age, genetics, smoking, thinness, and many diseases and drugs that impair bone health. An evaluation of these risk factors to identify candidates for osteoporosis screening and recommending nonpharmacologic measures such as good nutrition (especially adequate intake of protein, calcium, and vitamin D), regular physical activity, and avoiding smoking and excessive alcohol consumption are appropriate for all postmenopausal women. For women at high risk for osteoporosis, especially perimenopausal women with low bone density and other risk factors, estrogen or other therapies are available to prevent bone loss. For women with osteoporosis and/or other risk factors for fracture, including advanced age and previous fractures, the primary goal of therapy is to prevent new fractures. This is accomplished by combining nonpharmacologic measures, drugs to increase bone density and to improve bone strength, and strategies to reduce fall risk. If pharmacologic therapy is indicated, government-approved options include estrogen agonists/antagonists, bisphosphonates, RANK ligand inhibitors, parathyroid hormone-receptor agonists, and inhibitors of sclerostin.

CONCLUSIONS

Osteoporosis is a common disorder in postmenopausal women. Management of skeletal health in postmenopausal women involves assessing risk factors for fracture, reducing modifiable risk factors through dietary and lifestyle changes, and the use of pharmacologic therapy for patients at significant risk of osteoporosis or fracture. For women with osteoporosis, lifelong management is necessary. Treatment decisions occur continuously over the lifespan of a postmenopausal woman. Decisions must be individualized and should include the patient in the process of shared decision-making.

Insufficient persistence of and adherence to osteoporosis pharmacotherapy in Japan

INTRODUCTION

Only a few large-scale studies have examined the care gap in Japan. The aim of this study was to investigate the persistence of and adherence to osteoporosis pharmacotherapy in Japan.

MATERIALS AND METHODS

The rates of continuation (persistence) of and adherence to osteoporosis pharmacotherapy were investigated using medical insurance data, issued from July 2013 to December 2018, from the medical care system for elderly individuals in Hokkaido, Japan.

RESULTS

The study included 7918 male and 52,585 female patients. Persistence rates were 62.1% in the first year and 45.3% in the second year. There were 33,096 patients who discontinued medication; 8296 patients resumed medication during the observation period of 730 days. The median time to the discontinuation of medication for all the patients was 702 days. The 2-year medication possession ratio (MPR) was 63.8%; 30,989 patients (51.2%) had an MPR ≥ 80% and 20,788 (34.4%) had an MPR < 50%. Both the persistence and adherence were better in females than in males and worsened with increasing age. Comparisons of fracture history showed that persistence and MPR were higher in the no hip or vertebral fracture group, followed by hip fracture, vertebral fracture, and hip and vertebral fracture groups. Meanwhile, more patients in the hip fracture group had an MPR ≥ 80%.

CONCLUSION

Persistence of and adherence to osteoporotic pharmacotherapy are not very high in Japan. To bridge the care gap following osteoporosis pharmacotherapy, improvements are required for males, the elderly, and those with a history of vertebral fracture.

Denosumab, raloxifene, romosozumab and teriparatide to prevent osteoporotic fragility fractures: a systematic review and economic evaluation

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

The objectives were to evaluate the clinical effectiveness, safety and cost-effectiveness of non-bisphosphonates {denosumab [Prolia®; Amgen Inc., Thousand Oaks, CA, USA], raloxifene [Evista®; Daiichi Sankyo Company, Ltd, Tokyo, Japan], romosozumab [Evenity®; Union Chimique Belge (UCB) S.A. (Brussels, Belgium) and Amgen Inc.] and teriparatide [Forsteo®; Eli Lilly and Company, Indianapolis, IN, USA]}, compared with each other, bisphosphonates or no treatment, for the prevention of fragility fracture.

DATA SOURCES

For the clinical effectiveness review, nine electronic databases (including MEDLINE, EMBASE and the World Health Organization International Clinical Trials Registry Platform) were searched up to July 2018.

REVIEW METHODS

A systematic review and network meta-analysis of fracture and femoral neck bone mineral density were conducted. A review of published economic analyses was undertaken and a model previously used to evaluate bisphosphonates was adapted. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years for a simulated cohort of patients with heterogeneous characteristics. This was done for each non-bisphosphonate treatment, a strategy of no treatment, and the five bisphosphonate treatments previously evaluated. The model was populated with effectiveness evidence from the systematic review and network meta-analysis. All other parameters were estimated from published sources. An NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net monetary benefit was estimated using non-parametric regression. A probabilistic sensitivity analysis and scenario analyses were used to assess uncertainty.

RESULTS

Fifty-two randomised controlled trials of non-bisphosphonates were included in the clinical effectiveness systematic review and an additional 51 randomised controlled trials of bisphosphonates were included in the network meta-analysis. All treatments had beneficial effects compared with placebo for vertebral, non-vertebral and hip fractures, with hazard ratios varying from 0.23 to 0.94, depending on treatment and fracture type. The effects on vertebral fractures and the percentage change in bone mineral density were statistically significant for all treatments. The rate of serious adverse events varied across trials (0-33%), with most between-group differences not being statistically significant for comparisons with placebo/no active treatment, non-bisphosphonates or bisphosphonates. The incremental cost-effectiveness ratios were > £20,000 per quality-adjusted life-year for all non-bisphosphonate interventions compared with no treatment across the range of QFracture and FRAX scores expected in the population eligible for fracture risk assessment. The incremental cost-effectiveness ratio for denosumab may fall below £30,000 per quality-adjusted life-year at very high levels of risk or for high-risk patients with specific characteristics. Raloxifene was dominated by no treatment (resulted in fewer quality-adjusted life-years) in most risk categories.

LIMITATIONS

The incremental cost-effectiveness ratios are uncertain for very high-risk patients.

CONCLUSIONS

Non-bisphosphonates are effective in preventing fragility fractures, but the incremental cost-effectiveness ratios are generally greater than the commonly applied threshold of £20,000-30,000 per quality-adjusted life-year.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018107651.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 29. See the NIHR Journals Library website for further project information.

[Osteoporosis: long-term treatment versus drug holiday-what is the evidence?]

The occurrence of multiple vertebral fractures after discontinuation of denosumab in the treatment of osteoporosis has reopened the debate on the optimal treatment duration and drug holidays.In principle, there is a difference in this regard between the discontinuation of medications such as bisphosphonates and substances without bone retention such as selective estrogen receptor modulators (SERMs), denosumab or teriparatide. Even after the end of application bisphosphonates have a very long half-life in the bones. After cessation of drug intake there is a slow, slight increase of bone turnover markers. Even after cessation of the SERM raloxifene, a decline in bone density can be observed, as with the termination of teriparatide. In contrast to these osteoporosis medications, after cessation of denosumab, a steep and rapid increase in markers of bone resorption above baseline levels ("rebound") and a reduction in bone mineral density to initial values can be observed.Osteoporosis is a disease that carries an increased risk of fracture, which is reduced for the duration of osteoporosis treatment. In certain situations, the fracture risk is only temporarily raised. In these situations, cessation of the osteoporosis treatment is possible. Beyond these special clinical situations, however, osteoporosis needs to be addressed as a chronic disease with a permanently increased fracture risk and the indication for therapy should be evaluated according to the extent of the risk of fracture.What happens after discontinuation of anti-osteoporosis drugs? The various effects on bone turnover markers, bone mineral density and fracture incidence of the individual drug groups are presented in detail, as are the resulting recommendations of the task forces of the American Society of Bone and Mineral Research (ASBMR) and the European Calcified Tissue Society (ECTS).

Systemic Estrogen Use and Discontinuation After Alzheimer's Disease Diagnosis in Finland 2005-2012: A Nationwide Exposure-Matched Cohort Study

BACKGROUND

It is unknown whether cognitive status or diagnosed cognitive decline affects estrogen use.

OBJECTIVES

We assessed how common systemic estrogen use was among community-dwellers with Alzheimer's disease (AD) and a matched comparison cohort without AD.

METHODS

This study included an exposure-matched cohort of all Finnish community-dwelling women who received a clinically verified diagnosis of AD in 2005-2011 (N = 46,116; index cases) and an equally sized matched comparison cohort without AD. Follow-up began on the matching date (date of the AD diagnosis of the index case). Data on systemic estrogen use were obtained from the prescription register. Use initiation and discontinuation were assessed.

RESULTS

Altogether 3.1% of women with AD and 4.3% of women without AD used estrogen during the follow-up period. Only < 0.5% initiated use during the follow-up period, but 3.7% continued use until death. The prevalence of estrogen use 1 year after the AD diagnosis declined in 2005-2011.

CONCLUSIONS

There were no major differences in systemic estrogen use among Finnish women with AD when compared to those without AD. Although some persons initiated estrogen use after AD diagnosis and/or at an advanced age, the observed use patterns were mainly consistent with the current recommendations.

Antiresorptives: Safety Concerns-Clinical Perspective

Antiresorptive drugs, such as amino-bisphosphonates and denosumab (Dmab), have dominated osteoporosis therapies for over 20 years. Since osteoporosis is a chronic disease, antifracture therapy could continue for the rest of a patient's life. Phase III clinical trials for antiresorptive drugs assessed relatively small patient populations for short durations and excluded up to 80% of patients who might seek osteoporosis therapy in clinical practice. Postmarketing reports based upon millions of patient-years and long-term (>5 years) clinical administration have associated some previously unknown, rare adverse events with antiresorptive use including osteonecrosis of the jaw (ONJ) and atypical femur fractures (AFFs). In the osteoporosis patient population, who receive much lower doses of bisphosphonate (BP) or Dmab, the incidence of ONJ is estimated at 0.001% to 0.01%, which is only slightly higher than that seen in the general population. AFFs are insufficiency or fissure transverse fractures originating on the lateral cortex of the subtrochanteric or diaphyseal region of the femur becoming oblique as they progress medially when complete. Incidence rates of AFF range from 1.8/100,000 per year with a 2-year BP exposure to 113/100,000 per year with BP exposure from 8 to 9.9 years. Most recent pathogenic hypotheses of these rare events will be discussed.

Western Osteoporosis Alliance Clinical Practice Series: Evaluating the Balance of Benefits and Risks of Long-Term Osteoporosis Therapies

Osteoporosis is a chronic disease that requires life-long strategies to reduce fracture risk. Few trials have investigated the balance of benefits and risk with long-term use of osteoporosis therapies, and fewer still have investigated the consequences of treatment discontinuation. The best available evidence suggests that up to 10 years of treatment with an oral bisphosphonate maintains the degree of fracture risk reduction observed in the 3-year registration trials. With denosumab, 10 years of therapy appears to provide fracture risk reduction similar to or better than that observed in the 3-year registration trial. Available data suggest an increasing but low risk of fractures with atypical features with increasing duration of bisphosphonate therapy. Published data linking duration of therapy to osteonecrosis of the jaw are lacking for bisphosphonates and denosumab. Other side effects associated with denosumab or bisphosphonates do not appear to be related to therapy duration. The antifracture benefits of long-term therapy with bisphosphonates and denosumab in appropriately selected patients outweigh the low risk of serious side effects.

Longitudinal Change in Trabecular Bone Score during and after Treatment of Osteoporosis in Postmenopausal Korean Women

BACKGROUND

The aim of this study was to evaluate the longitudinal changes of trabecular bone score (TBS) during and after bisphosphonate (BP) treatment in postmenopausal Korean women with osteoporosis.

METHODS

We analyzed 191 patients who took BP and underwent bone mineral density (BMD) test for the period from January 2010 to December 2015. The mean follow up period during treatment and after treatment was 22.8 months and 18 months, respectively. The TBS and BMD values were evaluated by the percent changes relative to the baseline.

RESULTS

In 191 patients, who treated with BPs, L-spine BMD increased 3.65±0.5% and TBS increased 0.26±0.4% from baseline during first 1 year. At 2 to 4 years, the changes of BMD and TBS from baseline gradually increased up to 9.3±3.25% and 2.69±0.98% and both results showed statistically significant correlation. In 86 patients who stopped BPs, L-spine BMD decreased -0.54±1.07% and TBS increased 0.33±1.96% from baseline during 3 years follow up period.

CONCLUSIONS

Lumbar spine TBS increase over time with BPs treatment although the changes were less than that of BMD. Also, it preserve for years after stopping treatment, as the changes of lumbar spine BMD. The results of BMD and TBS showed significant correlation during treatment but not during drug withdrawal.

Evaluation and Treatment of Osteoporosis

As the population ages, the rates of osteoporotic fractures will increase, with postmenopausal women incurring most of these fractures. Diagnosis and treatment of osteoporosis are extremely important. Dual-energy x-ray absorptiometry scan screening is recommended in all women more than 65 years of age or in women aged 50 to 64 years with certain risk factors. Treatment should be considered if osteoporosis is present, there is a history of fragility fracture, or in the setting of osteopenia plus high risk for fracture.

Severe spontaneous vertebral fractures after denosumab discontinuation: three case reports

Osteoporosis treatments are usually given for a limited period of time in order to balance benefits and risks. We report three cases of postmenopausal women without any previous fragility fracture who presented severe spontaneous vertebral fractures after denosumab discontinuation. We think that the occurrence of these fractures could be explained by the severe rebound effect observed after denosumab discontinuation and that a consensus regarding the end of treatment with denosumab has to be defined.

Efficacy and safety of currently marketed anti-osteoporosis medications

During the past 2 decades, many interventions were proven effective in the management of postmenopausal osteoporosis. The objective of an anti-osteoporosis treatment is to reduce fracture rates, ideally at all skeletal sites (i.e. spine, hip, and other non-spine). The armamentarium against osteoporosis includes anti-resorptive agents (i.e. bisphosphonates, selective estrogen receptor modulators and denosumab), bone-forming agents (i.e. peptides from the parathyroid hormone family) and one agent with a dual mechanism of action (i.e. strontium ranelate). All these medications combine antifracture efficacy with a reasonable benefit/risk profile. However, the choice of a particular chemical entity, in one individual patient is based on the knowledge and expertise of the physician. Prioritization of drugs should be based on the individual profile of the patient, the severity of osteoporosis and the specific contraindications, warnings and precautions of use of the various available medications.

Understanding and communicating the benefits and risks of denosumab, raloxifene, and teriparatide for the treatment of osteoporosis

The number needed to treat is a valuable metric to determine the benefit of therapy, but it must be viewed against the respective number needed to harm. Denosumab and teriparatide (TPTD) have proven antifracture efficacy at vertebral and nonvertebral sites, whereas raloxifene has proven antifracture efficacy at the spine only. Denosumab use has been associated with a small, yet statistically significant, increased incidence of eczema and serious cellulitis. Raloxifene use has been associated with statistically significant increases in the risk of venous thromboembolism and possibly deadly stroke, although not an increase in total strokes. No significant, nontransient adverse events have been reported with TPTD use. When used for the treatment of postmenopausal osteoporosis, denosumab, raloxifene, and TPTD all generally have favorable risk-to-benefit profiles, but therapy-specific contraindications necessitate thoughtful consideration of all available clinical information and individualization of treatment decisions.

Current challenges in the treatment of osteoporosis: an opportunity for bazedoxifene

BACKGROUND

Osteoporosis affects millions of postmenopausal women worldwide. Osteoporosis-related fractures can lead to chronic pain, disability, systemic complications, and increased risk of recurrent fractures, resulting in increased healthcare costs and mortality. Because currently available therapies have unique benefit/risk profiles, challenges remain in selecting the most appropriate treatment for each osteoporotic woman. RESEARCH AND RESULTS: Bazedoxifene (BZA), a new selective estrogen receptor modulator, is being developed for postmenopausal osteoporosis. In a 3 year, global, phase 3 study, BZA significantly reduced the risk of new vertebral fractures and nonvertebral fractures in women with higher baseline fracture risk compared with placebo. In two extensions of this study, the efficacy of BZA in reducing vertebral fracture risk was sustained over 7 years. BZA improved lumbar spine and total hip bone mineral density compared with placebo at 3 and 5 years, and demonstrated a favorable safety/tolerability profile, with no endometrial or breast stimulation. BZA was cost-effective compared with raloxifene in a 3 year, head-to-head comparative trial. Indirect comparisons further suggest that BZA may be as effective as bisphosphonates in reducing risk of nonvertebral fractures in women at high risk of fracture. BZA demonstrated efficacy and safety for treating postmenopausal osteoporosis over 7 years, particularly in women at a higher fracture risk.

CONCLUSION

Because of its specific pharmacologic profile, BZA may be appropriate for postmenopausal women seeking a tolerable, safe, effective, and cost-effective long-term osteoporosis treatment.

How long should we treat?

Osteoporosis is a chronic disease, for which effective drugs are available. These drugs have reduced the risk of osteoporosis-related fractures in robust trials of 3-5 years duration. There is no evidence of anti-fracture efficacy for treatments of longer duration. The consequences of stopping treatments are very different for the different molecules. Bisphosphonates can be safely discontinued after 3-5 years of treatment if there was optimal adherence and if patients are no longer osteoporotic. This discontinuation cannot be applied in patients with recent fractures or for other treatments. Safety of prolonged treatment is a huge concern which must be managed appropriately. The decision of a prolonged treatment is driven by the underlying risk of fracture. This risk must be assessed regularly in order to share with the patient the benefit-risk ratio of prolonged treatment.

New therapeutics for osteoporosis

Two new approaches for the treatment of osteoporosis are summarized, each having arisen out of important new discoveries in bone biology. Odanacatib (ODN) inhibits the enzyme, cathepsin K, that is essential for the resorbing activity of osteoclasts. It is effective in preventing ovariectomy-induced bone loss in preclinical studies, and a phase II clinical study has shown inhibition of resorption sustained over five years. Outcome of a phase III study is awaited. The finding from mouse and human genetics that Wnt signaling is a powerful inducer of bone formation led to developments aimed at enhancing this pathway. Of the several approaches towards this, the most advanced is with a neutralizing antibody against sclerostin, the osteocyte-derived inhibitor of Wnt signaling. Preclinical studies show a powerful bone anabolic effect, and a clinical phase II study shows dose-dependent increases in bone formation and decreases in bone resorption markers.

Implications of osteoblast-osteoclast interactions in the management of osteoporosis by antiresorptive agents denosumab and odanacatib

Antiresorptive agents, used in the treatment of osteoporosis, inhibit either osteoclast formation or function. However, with these approaches, osteoblast activity is also reduced because of the loss of osteoclast-derived coupling factors that serve to stimulate bone formation. This review discusses how osteoclast inhibition influences osteoblast function, comparing the actions of an inhibitor of osteoclast formation [anti-RANKL/Denosumab (DMAB)] with that of a specific inhibitor of osteoclastic cathepsin K activity [Odanacatib (ODN)]. Denosumab rapidly and profoundly, but reversibly, reduces bone formation. In contrast, preclinical studies and clinical trials of ODN showed that bone formation at some skeletal sites was preserved although resorption was reduced. This preservation of bone formation appears to be due to effects of coupling factors, secreted by osteoclasts and released from demineralized bone matrix. This indicates that bone resorptive activities of osteoclasts are separable from their coupling activities.

Discontinuation of denosumab and associated fracture incidence: analysis from the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial

Osteoporosis is a chronic disease and requires long-term treatment with pharmacologic therapy to ensure sustained antifracture benefit. Denosumab reduced the risk for new vertebral, nonvertebral, and hip fractures over 36 months in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. Whereas discontinuation of denosumab has been associated with transient increases in bone remodeling and declines in bone mineral density (BMD), the effect on fracture risk during treatment cessation is not as well characterized. To understand the fracture incidence between treatment groups after cessation of investigational product, we evaluated subjects in FREEDOM who discontinued treatment after receiving two to five doses of denosumab or placebo, and continued study participation for ≥7 months. The off-treatment observation period for each individual subject began 7 months after the last dose and lasted until the end of the study. This subgroup of 797 subjects (470 placebo, 327 denosumab), who were evaluable during the off-treatment period, showed similar baseline characteristics for age, prevalent fracture, and lumbar spine and total hip BMD T-scores. During treatment, more placebo-treated subjects as compared with denosumab-treated subjects sustained a fracture and had significant decreases in BMD. During the off-treatment period (median 0.8 years per subject), 42% versus 28% of placebo- and denosumab-treated subjects, respectively, initiated other therapy. Following discontinuation, similar percentages of subjects in both groups sustained a new fracture (9% placebo, 7% denosumab), resulting in a fracture rate per 100 subject-years of 13.5 for placebo and 9.7 for denosumab (hazard ratio [HR] 0.82; 95% confidence interval [CI], 0.49-1.38), adjusted for age and total hip BMD T-score at baseline. There was no apparent difference in fracture occurrence pattern between the groups during the off-treatment period. In summary, there does not appear to be an excess in fracture risk after treatment cessation with denosumab compared with placebo during the off-treatment period for up to 24 months.

Potential role of odanacatib in the treatment of osteoporosis

Cathepsin K is a key enzyme involved in the degradation of organic bone matrix by osteoclasts. Inhibition of bone resorption observed in human and animal models deficient for cathepsin K has identified this enzyme as a suitable target for intervention by small molecules with the potential to be used as therapeutic agents in the treatment of osteoporosis. Odanacatib (ODN) is a nonbasic selective cathepsin K inhibitor with good pharmacokinetic parameters such as minimal in vitro metabolism, long half-life, and oral bioavailability. In preclinical studies, ovariectomized monkeys and rabbits treated with ODN showed substantial inhibition of bone resorption markers along with increases in bone mineral density (BMD). Significant differences were observed in the effects of ODN treatment compared with those of other antiresorptive agents such as bisphosphonates and denosumab. ODN displayed compartment-specific effects on trabecular versus cortical bone formation, with treatment resulting in marked increases in periosteal bone formation and cortical thickness in ovariectomized monkeys whereas trabecular bone formation was reduced. Furthermore, osteoclasts remained viable. Phase I and II studies conducted in postmenopausal women showed ODN to be safe and well tolerated. After 5 years, women who received ODN 50 mg weekly continuously from year 1 (n = 13), showed BMD increases from baseline of 11.9% at the lumbar spine, 9.8% at the femoral neck, 10.9% at the hip trochanter, and 8.5% at the total hip. Additionally, these subjects maintained a low level of the urine bone resorption marker N-terminal telopeptide/creatinine (−67.4% from baseline) through 5 years of treatment, while levels of serum bone-specific alkaline phosphatase remained only slightly reduced relative to baseline (−15.3%). In women who were switched from ODN to placebo after 2 years, bone turnover markers were transiently increased and BMD gains reversed after 12 months off medication. Adverse experiences in the ODN-treated group were not significantly different from the placebo group. In conclusion, available data suggests that cathepsin K inhibition could be a promising intervention with which to treat osteoporosis. Ongoing studies are expected to provide information on the long-term efficacy in fracture reduction and safety of prolonged treatment with ODN.

Therapeutic inhibition of cathepsin K-reducing bone resorption while maintaining bone formation

Osteoporosis is a disease of high bone remodeling with an imbalance of bone resorption over bone formation, resulting in decreased bone mineral density and deterioration of bone microarchitecture. From the emerging understandings of the molecular and cellular regulators of bone remodeling, potential new targets for therapeutic intervention for this disease have been identified. Cathepsin K (CatK), a cysteine protease produced by osteoclasts, is the primary enzyme mediating the degradation of the demineralized bone matrix. Current genetic and pharmacological evidence from studies in multiple preclinical species have consistently demonstrated that inhibition of CatK results in the reduction of bone resorption while allowing bone formation to continue. Early results from clinical studies with several investigational CatK inhibitors indicate that the impact of CatK inhibition on bone formation is distinct from that of either the bisphosphonates or the anti-receptor activator of nuclear factor-κB ligand antibody, denosumab. Odanacatib, a highly selective, reversible and potent inhibitor of CatK, is currently in phase III clinical trials for the treatment of postmenopausal osteoporosis.

Postmenopausal osteoporosis treatment with antiresorptives: effects of discontinuation or long-term continuation on bone turnover and fracture risk--a perspective

Osteoporosis may be a lifelong condition. Robust data regarding the efficacy and safety of both long-term osteoporosis therapy and therapy discontinuation are therefore important. A paucity of clinical trial data regarding the long-term antifracture efficacy of osteoporosis therapies necessitates the use of surrogate endpoints in discussions surrounding long-term use and/or discontinuation. Long-term treatment (beyond 3-4 years) may produce further increases in bone mineral density (BMD) or BMD stability, depending on the specific treatment and the skeletal site. Bisphosphonates, when discontinued, are associated with a prolonged reduction in bone turnover markers (BTMs), with a very gradual increase to pretreatment levels within 3 to 60 months of treatment cessation, depending on the bisphosphonate used and the prior duration of therapy. In contrast, with nonbisphosphonate antiresorptive agents, such as estrogen and denosumab, BTMs rebound to above pretreatment values within months of discontinuation. The pattern of BTM change is generally mirrored by a more or less rapid decrease in BMD. Although the prolonged effect of some bisphosphonates on BTMs and BMD may contribute to residual benefit on bone strength, it may also raise safety concerns. Adequately powered postdiscontinuation fracture studies and conclusive evidence on maintenance or loss of fracture benefit is lacking for bisphosphonates. Similarly, the effects of rapid reversal of bone turnover upon discontinuation of denosumab on fracture risk remain unknown. Ideally, studies evaluating the effects of long-term treatment and treatment discontinuation should be designed to provide head-to-head "offset" data between bisphosphonates and nonbisphosphonate antiresorptive agents. In the absence of this, a clinical recommendation for physicians may be to periodically assess the benefits/risks of continuation versus discontinuation versus alternative management strategies.

The effects of discontinuing long term alendronate therapy in a clinical practice setting

OBJECTIVE

To assess bone turnover markers (BTM) and bone mineral density (BMD) after discontinuation of alendronate treatment used for five or more years.

SUBJECTS AND METHODS

40 patients (pt) with post-menopausal osteoporosis treated with alendronate (10 mg/d) for at least five years (Group 1, G1) had their medication discontinued. Group 2 (G2): 25 pt treated with alendronate for at least one year. Group 3 (G3): 23 treatment-naïve osteoporotic pt. BMD was evaluated in G1 and G2 at baseline and after 12 months. Collagen type I cross-linked C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP) levels were measured in all pt at baseline, and in G1 and G2 every three months for 12 months. Data were analyzed using ANOVA on ranks and Mann-Whitney tests.

RESULTS

Mean BMD values in G1 and G2 did not differ during follow-up. However, 16 pt (45.7%) in G1 and one (5.2%) in G2 lost BMD (P < 0.001). BTM at baseline was not different between G1 and G2, and both were lower than G3. A significant increase in BTM levels was detected in G1 pt after three months, but not in G2.

CONCLUSION

Observed BMD loss and BTM rise after alendronate withdrawal imply that bone turnover was not over suppressed, and alendronate discontinuation may not be safe.

A reappraisal of generic bisphosphonates in osteoporosis

The competitive price of generic bisphosphonates has had a marked effect on practice guidelines, but an increasing body of evidence suggests that they have more limited effectiveness than generally assumed.

INTRODUCTION

The purpose of this study is to review the impact of generic bisphosphonates on effectiveness in the treatment of osteoporosis.

METHODS

This study is a literature review.

RESULTS

A substantial body of evidence indicates that many generic formulations of alendronate are more poorly tolerated than the proprietary preparations which results in significantly poorer adherence and thus effectiveness. Poorer effectiveness may result from faster disintegration times of many generics that increase the likelihood of adherence of particulate matter to the oesophageal mucosa. Unfortunately, market authorisation, based on the bioequivalence of generics with a proprietary formulation, does not take into account the potential concerns about safety. The poor adherence of many generic products has implications for guideline development, cost-effectiveness and impact of treatment on the burden of disease.

CONCLUSIONS

The impact of generic bisphosphonates requires formal testing to re-evaluate their role in the management of osteoporosis.

Bone remodeling in postmenopausal women who discontinued denosumab treatment: off-treatment biopsy study

Denosumab is a fully human monoclonal antibody that neutralizes the activity of RANKL, leading to the inhibition of osteoclast maturation, bone-resorbing activity, and survival. Evaluation of trans-iliac crest bone biopsy specimens in the phase 3 pivotal fracture study with denosumab in postmenopausal women with osteoporosis showed evidence of reduced bone turnover at the tissue level in subjects receiving denosumab, and up to one-third of subjects did not have evidence of tetracycline labeling in trabecular or cortical bone. Discontinuation of denosumab therapy has demonstrated that the effects of denosumab are reversible, as assessed by biochemical markers of bone turnover (BTM) and BMD. The precise nature of changes that occur at the tissue level with denosumab discontinuation have not been explored. Fifteen subjects were enrolled in a cohort study to evaluate the effects of denosumab discontinuation at the tissue level. Subjects had discontinued osteoporosis treatment for a mean time of 25.1 months (range 21 to 29 months). Bone histomorphometry results were compared with results from placebo-treated women with osteoporosis in the denosumab phase 3 pivotal fracture bone biopsy substudy, and BTMs were compared with subjects' pretreatment values. The results of this study showed normal histology and bone remodeling similar to those observed in untreated postmenopausal women with osteoporosis. With treatment cessation, 100% of biopsy specimens had evidence of tetracycline labels. Biochemical markers were comparable to and highly correlated with pretreatment levels. These data confirm that the effects of denosumab on bone turnover at the tissue level are fully reversible.

Duration of treatment in postmenopausal osteoporosis: how long to treat and what are the consequences of cessation of treatment?

Although a variety of medications are effective for the treatment of postmenopausal osteoporosis, there is concern that long-term use may incur side effects. Consequently, some have proposed discontinuing or temporarily suspending treatment after a defined period of time. As the benefits of fracture risk reduction may recede during this "drug holiday", the clinician may be faced with deciding when to resume therapy (and with which agent) while avoiding the possible cumulative risk of side effects. This article summarizes data regarding length of treatment and the effects of cessation of treatment on bone density, bone turnover markers, and fracture risk.

Current options for the management of postmenopausal osteoporosis

INTRODUCTION

Osteoporosis is a well-recognized disease with severe consequences if left untreated. The prevention of osteoporosis-associated fractures should include fall prevention, calcium supplementation and life-style advice, as well as pharmacological therapy using agents with proven antifracture efficacy.

AREAS COVERED

This manuscript offers an evidence-based critical assessment of the currently available efficacy data on all new chemical entities that have been granted a marketing authorization for the management of primary osteoporosis in women.

EXPERT OPINION

The availability of new therapeutic agents makes clinical decision making in osteoporosis more complex. Therapeutic decisions should be based on a balance between the benefits and risks of treatment, which must be carefully considered in each particular case, both by the physician and the patient. Indeed, no single agent is appropriate for all patients. Therefore, treatment decisions should be made on a tailor-made basis, taking into account all measures of treatment effect and risk, before making informed judgments about the best individual treatment option.

Cathepsin K: its skeletal actions and role as a therapeutic target in osteoporosis

Bone remodeling consists of two phases--bone resorption and bone formation--that are normally balanced. When bone resorption exceeds bone formation, pathologic processes, such as osteoporosis, can result. Cathepsin K is a member of the papain family of cysteine proteases that is highly expressed by activated osteoclasts. Cathepsin K readily degrades type I collagen, the major component of the organic bone matrix. With such a major role in the initial process of bone resorption, cathepsin K has become a therapeutic target in osteoporosis. The antiresorptive properties of cathepsin K inhibitors have been studied in phase I and phase II clinical trials. Phase III studies are currently underway for odanacatib, a selective cathepsin K inhibitor.

If you don't take it - it can't work: the consequences of not being treated or nonadherence to osteoporosis therapy

Osteoporosis is a growing problem worldwide, linked to an increasingly aging population. Despite the availability of a wide variety of treatments for osteoporosis, a significant number of patients are either not being prescribed treatment or discontinue therapy as early as 6 months after initiation. The reasons for a lack of adherence are many but poor adherence increases the risk of fracture and, therefore, the disease burden to the patient and society. Results from large-scale, randomized clinical studies have shown that different osteoporosis treatments are efficacious in reducing the risk of fracture. Studies assessing the effects of discontinuing osteoporosis therapies show that some treatments appear to continue to protect patients from the risk of future fracture even when treatment is stopped. However, these trials involve patients who have been compliant with treatment for between 2 and 5 years, a situation not reflective of real-world clinical practice. In reality, patients who discontinue therapy within the first 6 months may never achieve the optimum protection from fracture regardless of which treatment they have been prescribed. Clinicians need to develop management strategies to enable patients to adhere to their treatment. This will ultimately result in better prevention of fracture and a lower burden of disease to society and patients.

Treatment of osteoporosis and reduction in risk of invasive breast cancer in postmenopausal women with raloxifene

INTRODUCTION

Raloxifene, a non-steroidal selective estrogen receptor modulator (SERM), offers a new dimension for the treatment and prevention of osteoporosis and risk reduction of invasive breast cancer in postmenopausal populations at high risk. Both osteoporosis and breast cancer are important public health issues for postmenopausal women. It is well known that estrogen and estrogen receptors play an important role in the pathogenesis of both diseases. Initially, hormone replacement therapy (HRT) was used for the purpose of preventing and treating postmenopausal osteoporosis. However, HRT significantly contributed to an increase in breast cancer risk. The SERM, raloxifene, is used for the prevention and for the treatment of postmenopausal osteoporosis and reducing the risk of invasive breast cancer in postmenopausal women.

AREAS COVERED

This article reviews the emerging evidence of the efficacy of raloxifene in postmenopausal women, summarizes the results and places in perspective their therapeutic uses for women having either a high risk of osteoporosis or breast cancer. Emerging clinical evidence suggests bisphosphonates, currently used as drugs for the treatment of osteoporosis, may also reduce breast cancer risk. The status of other SERMs and bisphosphonates are included for completeness. A Medline search of raloxifene, osteoporosis, breast cancer and SERMs was used to derive a database of 355 references.

EXPERT OPINION

Readers will understand the value of raloxifene to prevent osteoporosis and breast cancer in postmenopausal women. Although most women do not require pharmacotherapy for menopausal symptoms, many are severely affected by osteoporosis or breast cancer at and beyond menopause and, for such women, pharmacologic intervention is important if they are to retain an acceptable quality of life. It is reasonable to use raloxifene or bisphosphonate as an appropriate drug that targets symptom-free postmenopausal women for treatment and prevention of osteoporosis but raloxifene is proven to reduce the incidence of invasive breast cancer.

Evidence-based guidelines for the pharmacological treatment of postmenopausal osteoporosis: a consensus document by the Belgian Bone Club

Several drugs are available for the management of postmenopausal osteoporosis. This may, in daily practice, confuse the clinician. This manuscript offers an evidence-based update of previous treatment guidelines, with a critical assessment of the currently available efficacy data on all new chemical entities which were granted a marketing authorization. Osteoporosis is widely recognized as a major public health concern. The availability of new therapeutic agents makes clinical decision-making in osteoporosis more complex. Nation-specific guidelines are needed to take into consideration the specificities of each and every health care environment. The present manuscript is the result of a National Consensus, based on a systematic review and a critical appraisal of the currently available literature. It offers an evidence-based update of previous treatment guidelines, with the aim of providing clinicians with an unbiased assessment of osteoporosis treatment effect.

Long-term safety and efficacy of raloxifene in the prevention and treatment of postmenopausal osteoporosis: an update

The integrity of bone tissue and its remodeling that occurs throughout life requires a coordinated activity of osteoblasts and osteoclasts. The decreased estrogen circulating level during postmenopausal transition, with a prevalence of osteoclastic activity over osteoblastic activity, represents the main cause of bone loss and osteoporosis. Osteoporosis is a chronic disease requiring long-term therapy and it is important to evaluate the efficacy and safety of treatments over several years, as the fear of health risks is a common reason for discontinuing therapy. Raloxifene is a selective estrogen receptor modulator (SERM) leading to estrogen-agonist effects in some tissues and estrogen-antagonist effects in others. Raloxifene is effective to prevent and treat postmenopausal vertebral osteoporosis, with reduction of spine fractures and, in post-hoc analyses, non-spine fractures in high-risk subjects. Moreover, raloxifene reduces the risk of invasive breast cancer and improves the levels of serum lipoprotein but with an increased risk of venous thromboembolism and fatal stroke, without significant change in the incidence of coronary events. For these reasons the overall risk-benefit profile is favorable. Therefore, when considering the use of raloxifene in a postmenopausal woman, we should take into account the osteoporosis-related individual risk and weigh the potential benefits, skeletal and extra-skeletal, against the health risks.

Management of osteoporosis in postmenopausal women: 2010 position statement of The North American Menopause Society

OBJECTIVE

To update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2006 regarding the management of osteoporosis in postmenopausal women.

METHODS

NAMS followed the general principles established for evidence-based guidelines to create this updated document. A panel of clinicians and researchers expert in the field of metabolic bone diseases and/or women's health was enlisted to review the 2006 NAMS position statement, compile supporting statements, and reach consensus on recommendations. The panel's recommendations were reviewed and approved by the NAMS Board of Trustees.

RESULTS

Osteoporosis, which is especially prevalent among older postmenopausal women, increases the risk of fractures. Hip and spine fractures are associated with particularly high morbidity and mortality in this population. Given the health implications of osteoporotic fractures, the primary goal of osteoporosis therapy is to prevent fractures, which is accomplished by slowing or stopping bone loss, maintaining bone strength, and minimizing or eliminating factors that may contribute to fractures. The evaluation of postmenopausal women for osteoporosis risk requires a medical history, physical examination, and diagnostic tests. Major risk factors for postmenopausal osteoporosis (as defined by bone mineral density) include advanced age, genetics, lifestyle factors (such as low calcium and vitamin D intake, smoking), thinness, and menopause status. The most common risk factors for osteoporotic fracture are advanced age, low bone mineral density, and previous fracture as an adult. Management focuses first on nonpharmacologic measures, such as a balanced diet, adequate calcium and vitamin D intake, adequate exercise, smoking cessation, avoidance of excessive alcohol intake, and fall prevention. If pharmacologic therapy is indicated, government-approved options are bisphosphonates, selective estrogen-receptor modulators, parathyroid hormone, estrogens, and calcitonin.

CONCLUSIONS

Management strategies for postmenopausal women involve identifying those at risk for fracture, followed by instituting measures that focus on reducing modifiable risk factors through dietary and lifestyle changes and, if indicated, pharmacologic therapy.

The effect of cessation of raloxifene treatment on bone turnover in postmenopausal women

There is evidence to suggest accelerated bone loss following estrogen cessation. The effect of cessation of raloxifene therapy on bone turnover is unknown. Our aim was to determine the effect of cessation of raloxifene treatment on bone turnover and bone mineral density (BMD) in postmenopausal, osteopenic women. Women aged 50 to 80 years received raloxifene for 96 weeks and were then randomized to continue raloxifene (group 1, n=20) or placebo (group 2, n=20) for a further 96 weeks. A third group (group 3, n=14) received no treatment. Bone turnover markers and bone density (BMD) were measured throughout the study. Raloxifene treatment for 96 weeks resulted in a decrease in bone turnover (PINP by 31%) and an increase in spine BMD (by 2%) but no change in hip BMD for groups 1 and 2. Continuation of raloxifene (group 1) maintained these changes. Following cessation of raloxifene (group 2), bone markers returned to baseline levels (by 120 weeks). Hip BMD was decreased by 2% at 192 weeks compared to baseline. Bone markers in the controls (group 3) remained at the upper limit of the reference range throughout, with decreases in BMD of 2.3% (spine) and 2.8% (hip). Bone loss following cessation of raloxifene therapy at 96 weeks was greater than in the control group, suggesting accelerated bone loss. The beneficial effect on bone turnover of 96 weeks of raloxifene was lost 6 months after cessation of treatment.

[Austrian guidance for the pharmacological treatment of osteoporosis in postmenopausal women--update 2009]

Osteoporosis is a systemic skeletal disease characterized by diminished bone mass and deterioration of bone microarchitecture, leading to increased fragility and subsequent increased fracture risk. Therapeutic measures therefore aim at reducing individual fracture risk. In Austria, the following drugs, all of which have been proven to reduce fracture risk, are currently registered for the treatment of postmenopausal osteoporosis: alendronate, risedronate, etidronate, ibandronate, raloxifene, teriparatide (1-34 PTH), 1-84 PTH, strontium ranelate and salmon calcitonin. Fluorides are still available, but their role in daily practice has become negligible. Currently, there is no evidence that a combination of two or more of these drugs could improve anti-fracture potency. However, treatment with PTH should be followed by the treatment with an anticatabolic drug such as bisphosphonates. Calcium and vitamin D constitute an important adjunct to any osteoporosis treatment.

Differences in persistence among different weekly oral bisphosphonate medications

SUMMARY

We evaluated the differences in persistence with weekly oral bisphosphonate therapy according to the initial drug. Persistence to weekly oral preparations remains suboptimal, particularly in patients who receive generic alendronate. Alternative solutions are needed to improve the real life effectiveness of osteoporosis therapies.

INTRODUCTION

Poor persistence is widespread with oral osteoporosis (OP) therapy. The objective of this study was to evaluate the persistence among OP patients started on weekly oral bisphosphonates (BP).

METHODS

Patients newly initiated on branded risedronate, branded alendronate, or generic alendronate once weekly were selected from the Régie de l'Assurance Maladie du Québec databases. The cohort included patients with and without a previous OP fracture. The probability and the risk factors for early discontinuation were estimated using Cox regression models.

RESULTS

The study cohort included 32,804 patients. After 1 year, a significant difference in persistence on oral BP therapy was found. The patients started on branded risedronate were 11% more likely to stop OP therapy than patients started on branded alendronate. Risk of discontinuation doubled in patients initiated with generic alendronate compared to patients started on branded alendronate. Male gender was associated with a 25% increase risk of early discontinuation. No statistical association was found between previous OP fracture and early discontinuation.

CONCLUSION

This study provides further evidence of poor persistence to newly initiated oral weekly BP therapies, particularly for the patients started on generic alendronate.

Bisphosphonates: how do they work?

Bisphosphonates (BPs) are taken up preferentially by the skeleton and decrease osteoclast-mediated bone resorption. The capacity of the skeleton to retain BPs is large, and there is no indication for saturation of binding sites with the doses used in osteoporosis. The anti-resorptive action of BPs includes their selective binding to calcium crystals and their subsequent release and uptake by the osteoclasts. There are differences in the affinities of PBs for bone as well as in their anti-resorptive potencies, and the whole molecule is responsible for their inhibitory effect on bone resorption. At the tissue level, they decrease the rate of bone resorption and turnover, increase bone mineral density, and maintain or improve structural and material properties of bone and thereby reduce the risk of fractures. Current studies address questions related primarily to the pharmacological properties of these compounds that are essential for their optimal clinical use, such as for example long-term safety and efficacy.

Rationale for using raloxifene to prevent both osteoporosis and breast cancer in postmenopausal women

Both osteoporosis with fracture and breast cancer are important health issues for postmenopausal women. It is well known that estrogen and estrogen receptors (ERs) play an important role in the pathogenesis of both diseases. In past decades, hormone therapy (HT), mainly estrogen plus progestin (EPT), has been frequently used for the purpose of preventing and treating postmenopausal osteoporosis because of its efficacy, but it also contributes to a significant increase in breast cancer. Currently, there is a dilemma regarding the use of estrogen for postmenopausal women. Fortunately, an increasing understanding of the action of estrogen has led ultimately to the design of new drugs that work by virtue of their interaction with the ER; these drugs have come to be known as selective estrogen receptor modulators (SERMs), and are not only effective in preventing osteoporosis and managing those with osteoporosis, but also in decreasing the incidence of breast cancer. Among these SERMs, raloxifene may be the most attractive agent based on the evidence from five recent large trials (Multiple Outcomes of Raloxifene Evaluation [MORE], Continuing Outcomes Relevant to Evista [CORE], Raloxifene Use for the Heart [RUTH], Study of Tamoxifen and Raloxifene [STAR], and Evista Versus Alendronate [EVA]). The former three trials showed that raloxifene not only decreases the incidence of osteoporosis-associated fractures, but also has efficacy in breast cancer prevention. The head-to-head comparison with the anti-fracture agent alendronate (EVA trial) and the chemoprevention agent tamoxifen (STAR trial) further confirmed that raloxifene is a better choice. We concluded that since there is an absence of a therapeutic effect on relieving climacteric symptoms and there is the presence of a potential risk of thromboembolism in the use of raloxifene, this drug can be prescribed for clear indications, such as the management of osteoporosis, the prevention of fracture, and decreasing the incidence of invasive breast cancer, with careful monitoring for thromboembolism. It is reasonable to use raloxifene as an appropriate medicine that targets climacteric symptom-free postmenopausal women because of its overall favorable risk-benefit safety profile using the global index proposed by the Women's Health Initiation (WHI).

The effect of prior bisphosphonate exposure on the treatment response to teriparatide in clinical practice

Our objective was to determine the effect of prior bisphosphonate exposure on the treatment response to teriparatide. All patients started on teriparatide in our hospital are entered into a database. All patients who had at least 12 months' treatment were identified. Patients were divided into two groups depending on whether or not they had prior bisphosphonate exposure, and the response to teriparatide was compared using procollagen of type 1 N-terminal propeptide (P1NP) and bone mineral density (BMD). Fifty-two patients had been treated for at least 12 months, 38 with prior bisphosphonate exposure and 14 without. The mean duration of bisphosphonate treatment was 67 months, discontinued a mean of 1 month previously. P1NP increased significantly at 3 and 6 months in both groups. However, those without previous bisphosphonate treatment had a higher baseline P1NP (49 vs. 30 microg/L, P<0.01), and this remained higher at 3 months (109 vs. 71 microg/L, P=0.10) and 6 months (183 vs. 126 microg/L, P=0.06), although the difference was not significant. In the prior bisphosphonate and bisphosphonate naive groups, respectively, the change in spinal BMD was 9.0% and 7.8% (P=0.54) at 12 months and 9.8% and 6.1% (P=0.30) at 18 months. The respective change in hip BMD was 1.0% and -0.3% (P=0.36) at 12 months and 2.8% and 1.3% (P=0.44) at 18 months. There was a trend toward a smaller but still significant increase in P1NP in response to teriparatide in bisphosphonate-treated patients. Although this suggests a blunting of the anabolic effects, in our clinic population this did not result in a reduction in BMD gain.

Assessing the risk of bone fracture among postmenopausal women who are receiving adjuvant hormonal therapy for breast cancer

OBJECTIVE

To understand better the true impact of widespread adoption of adjuvant aromatase inhibitor (AI) therapy on postmenopausal breast cancer patients' risk of bone fracture.

METHODS

Data from three different studies were used to estimate the relative risk of bone fracture for each of the following groups of women (i.e., versus a control group of healthy postmenopausal women): (a) healthy postmenopausal women receiving tamoxifen; (b) postmenopausal women who had received treatment for early breast cancer; (c) postmenopausal breast cancer patients on adjuvant tamoxifen therapy; (d) postmenopausal breast cancer patients on adjuvant anastrozole therapy. The results of these analyses were then used to estimate the likely incidence of clinical fracture among such populations in 'real-life' clinical practice.

RESULTS

Breast cancer survivors were calculated to be at increased risk of clinical bone fracture (i.e., RR 1.15 vs. control group over 5 years). Breast cancer patients initiated on adjuvant anastrozole were also calculated to be at increased risk of bone fracture (RR = 1.36 vs. control group over 5 years), while the calculated risk of fracture among tamoxifen-treated breast cancer patients was similar to that observed in the control population (RR = 0.91).

CONCLUSION

Breast cancer patients are at increased risk of clinical bone fracture (compared with the general postmenopausal population) and adjuvant anastrozole therapy slightly adds to this risk. Importantly, however, the absolute risk of bone fracture appears to remain low in each of the evaluated patient populations, suggesting that fear of fracture should not prevent the initiation of adjuvant aromatase inhibitor therapy.