Monthly oral ibandronate therapy in postmenopausal osteoporosis: 1-year results from the MOBILE study

Bisphosphonates

Osteoporosis is the result of bone loss due to an imbalance in bone turnover such that bone resorption exceeds bone formation. Bisphosphonates are potent inhibitors of osteoclast activity that reduce bone turnover and re-establish the balance between bone resorption and formation. In clinical studies, several bisphosphonates prevent bone loss, preserve bone structure, improve bone strength and, in patients with osteoporosis, substantially reduce fracture risk. They are effective in multiple clinical settings including postmenopausal osteoporosis, low bone mass in men and drug-induced bone loss. Intermittent oral dosing and intravenous administration are more convenient than the original daily dosing regimen. These drugs are generally well tolerated and have an excellent safety profile in that serious side effects are uncommon. Potent bisphosphonates are generally the preferred treatment option for most patients with or at risk for osteoporosis.

Use of osteoporosis medications in older nursing facility residents

INTRODUCTION

Epidemiologic studies demonstrated that 70% to 85% of nursing home residents have osteoporosis. Few studies report comprehensive information about treatment of osteoporosis in nursing facilities.

OBJECTIVE

To determine the prevalence of osteoporosis treatment and identify resident characteristics associated with the use of antiresorptive medications or supplements indicated to treat osteoporosis in nursing homes.

METHODS

The study design was cross-sectional. The Systematic Assessment of Geriatric Drug Use via Epidemiology database provided the data. From this database, 186,221 residents were identified as newly admitted to nursing facilities in Kansas, Maine, Missouri, Ohio, and South Dakota between 1998 and 2000. The outcome measure was the use of antiresorptive medications (alendronate, risedronate, calcitonin, estrogen, raloxifene) or supplements (calcium with vitamin D) indicated for treatment of osteoporosis. The independent variables included demographic, health status, and fracture risk factors.

RESULTS

Of the overall sample, 9.1% received antiresorptive medications and/or supplements indicated for osteoporosis treatment. The most commonly used treatment was the combination of calcium and vitamin D (5.0%). Calcitonin (2.5%) use exceeded that of any other antiresorptive. Multivariable logistic regression analyses revealed that a diagnosis of osteoporosis and female gender were strongly associated with being more likely to receive an osteoporosis treatment (OR 6.34 with 95% CI 6.11-6.64 and OR 2.67 with 95% CI 2.53-2.83 respectively). The number of medications residents received was also strongly associated with receiving osteoporosis treatment. Being black and having 4 or more active diagnoses were strongly associated with lower odds of receiving treatment (OR 0.63 with 95% CI 0.57-0.68 and OR 0.71 with 95% CI 0.68-0.74 for 4 to 6 diagnoses).

DISCUSSION

Newly admitted nursing facility residents infrequently received an indicated osteoporosis treatment, including calcium with vitamin D, despite the expected high prevalence of osteoporosis in this setting. Few demographic, health status, and fracture risk factors were strongly associated with receiving indicated treatment.

Aromatase inhibitors and bone

The decrease in estrogen levels with the use of aromatase inhibitors results in an increase in the rate of bone remodelling. This result in an acceleration of bone loss, and probably to an increase in the risk of fractures. The risk of fracture is particularly high in the older woman and in the woman with a low bone mineral density. We have a number of proven treatments for the treatment of postmenopausal osteoporosis and it is likely that some of these, particularly bisphosphonates, could be effective at preventing bone loss with aromatase inhibitors.

Update on the use of bisphosphonates in the management of postmenopausal osteoporosis by obstetricians-gynecologists

Obstetricians-gynecologists often have a special and long-term relationship with their patients and are ideally placed to assess their fracture risk and to institute appropriate therapy for osteoporosis. Assessment of risk factors according to the World Health Organization and more recent guidelines (e.g., age, smoking history, previous fracture, parental fracture, corticosteroid use, weight) enables the clinician to target patients for testing of bone mineral density by techniques such as dual-energy x-ray absorptiometry at the proximal femur. The current therapy of choice is an oral bisphosphonate, which has proven efficacy in increasing bone mineral density, reducing bone-turnover markers, and reducing fracture rates. Their main drawback is inconvenient dosing requirements, which necessitates taking the drug in the morning at least 30 minutes before the first meal or drink of the day; this may contribute to poor adherence with therapy and suboptimal outcomes. The availability of daily or weekly (alendronate and risedronate) or monthly (ibandronate) bisphosphonates means that patients can have therapy at their preferred frequency, and along with education regarding lifestyle issues such as nutrition, exercise, smoking, and alcohol use, and measures to reduce tripping in the home, should reduce the prevalence of osteoporotic fractures.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader should be able to recall that there are high-risk fracture patients, explain that Ob/Gyn physicians should target their diagnostic and treatment options to these patients, and state that there are ways that increase compliance to recommended bisphosphonates in addition to the recommended lifestyle changes.

"Osteoporosis and orthopods" incidences of osteoporosis in distal radius fracture from low energy trauma

Fracture of the distal radius from low energy trauma is a common presentation to orthopaedic trauma services. This fragility type fracture is associated with underlying osteoporosis. Osteoporosis is a 'silent disease' where fragility fracture is a common presentation. Orthopaedic surgeons may be the only physician that these patients encounter. We found a high percentage of female patients who sustained a fragility fracture of the distal radius have an underlying osteoporosis. Further management of osteoporosis is important to prevent future fragility fractures.

Changes in bone remodelling and antifracture efficacy of intermittent bisphosphonate therapy: implications from clinical studies with ibandronate

Bisphosphonates reduce the rate of bone resorption and bone remodelling. Given daily, they decrease the risk of fractures in postmenopausal osteoporosis. When bisphosphonates were given at extended drug-free intervals this antifracture efficacy was generally not seen. This may be due to the different pattern of bone remodelling changes. Data from randomised clinical studies of ibandronate, given orally or intravenously, at different doses and for variable time intervals to women with osteoporosis were examined to explore the relationship between intermittent bisphosphonate therapy, changes in bone resorption and fracture risk. The magnitude of the reduction of the rate of bone resorption at the end of the drug-free interval rather than its fluctuation pattern after bisphosphonate administration determines antifracture efficacy, provided that these fluctuations occur within the premenopausal range. Prolongation of the drug-free interval beyond 2 weeks should be compensated by a dose higher than the cumulative daily dose.

New and emerging treatments for osteoporosis

PURPOSE OF REVIEW

This review will focus on three new treatments for postmenopausal osteoporosis which have either been recently released (intravenous ibandronate), or have completed (zoledronic acid) or are currently in (denosumab) phase III trials.

RECENT FINDINGS

A number of agents have demonstrated fracture risk reduction in randomized clinical trials, however, successful treatment of osteoporosis in the individual patient remains a challenge. Adherence to, and persistence with, all current osteoporosis medications are poor, being approximately 50% at 1 year for weekly bisphosphonates. Poor adherence to therapy makes it unlikely that the significant fracture reduction seen in clinical trials will be realized in clinical practice.

SUMMARY

New therapies will not only have to demonstrate safety and efficacy, but also provide some advantage to patient persistence through either less frequent dosing schedules or elimination of gastrointestinal disturbances, the most common adverse effects encountered with bisphosphonates. This review will focus on three such agents that have either been recently released (intravenous ibandronate), or have completed (zoledronic acid) or are currently in (denosumab) phase III trials.

Clodronic acid in the treatment of postmenopausal osteoporosis

BACKGROUND

Clodronic acid, a first-generation bisphosphonate, has been successfully used in the treatment of high bone turnover states, Paget's disease and osteolytic bone metastases. However, controversies remain over its optimal dosage and method of administration in the treatment of postmenopausal osteoporosis. In this study we aimed to evaluate the effect of clodronic acid treatment for 3 years on bone mineral density (BMD) in women with postmenopausal osteoporosis.

METHODS

This was a prospective, open-label, randomised, controlled study that was conducted in an outpatient clinic at the Bone Metabolism Unit of a tertiary referral centre university hospital. Thirty postmenopausal women (age range 48-73 years) with osteoporosis and a control group of 49 osteoporotic women (age range 47-74 years) received randomised therapy. The clodronic acid group of participants received oral doses of clodronic acid 800 mg plus elemental calcium 500 mg and 400 IU of vitamin D daily, while the control group was treated with calcium and vitamin D only. BMD was measured by dual energy x-ray absorptiometry at yearly intervals. Biochemical markers of bone turnover were also measured.

RESULTS

In this clinical study of postmenopausal women with osteoporosis, 36 months of clodronic acid treatment significantly increased average femoral neck BMD by 3.2 +/- 2.9%, trochanter BMD by 2.2 +/- 2.9% and lumbar spine BMD by 3.1 +/- 3%. In the control group, femoral neck, trochanter and lumbar spine BMD decreased by -6 +/- 2.7%, -7.3 +/- 2.5% and -5.4 +/- 2%, respectively (p<0.01, p<0.05 and p<0.05 for clodronic acid vs control, respectively). There was a significant decrease in urinary hydroxyproline (-38.3%) over 3 years in the clodronic acid group compared with baseline (p<0.05), while no significant change occurred in the control group. Clodronic acid was well tolerated and compliance was good. There were no clinically meaningful differences in the incidence of individual adverse events between the groups.

CONCLUSION

These results indicate that daily oral administration of clodronic acid 800 mg provides benefits to skeletal bone density in osteoporotic postmenopausal women. Calcium and vitamin D supplementation alone did not prevent further bone loss.

How to deal with multiple treatment or dose groups in randomized clinical trials?

Multiplicity adjustment in general is currently a controversial topic. This review focuses on the proof of efficacy in randomized clinical trials. The ICH guidelines mandate control of the familywise error rate. Confidence intervals are clinically more appropriate than P-values or yes/no decisions. Therefore, simultaneous confidence intervals are proposed for several designs and aims in clinical trials. The computation of simultaneous confidence intervals for the difference or the ratio is demonstrated by means of real data examples using the R-packages multcomp and mratios. A special problem is the evaluation of dose-finding trials with and without the assumption that the effects increase with increasing doses. Simultaneous intervals are presented not only for one-way layouts and normal distributed endpoints, but also for higher way layouts, generalized linear models, and mixed models. Under importance ordering, the conditional testing of all hypotheses at level alpha will be shown using the intersection-union test principle. Other multiplicity issues (i.e. multiple endpoints, multiple analyses, and subgroup analyses) are discussed.

Clinical evaluation of novel bisphosphonate dosing regimens in osteoporosis: The role of comparative studies and implications for future studies

BACKGROUND

Daily nitrogen-containing bisphosphonates have shown antifracture efficacy in many studies of postmenopausal osteoporosis. However, current dosing schedules are often inconvenient or impractical for patients. Efforts to reduce dosing frequency to improve adherence (ie, compliance and persistence), and therefore treatment outcomes, are ongoing. Although a number of trial designs can be used to consider the efficacy of therapy, comparing the efficacy of different regimens should only be undertaken in purposefully designed head-to-head studies.

OBJECTIVE

This article summarizes the design and conduct of clinical studies that have investigated alternative bisphosphonate regimens and those that have directly compared different approved bisphosphonates. It also explores the implications for future studies of postmenopausal osteoporosis treatment.

METHODS

Using the terms bisphosphonate, daily, weekly, and monthly, a search (completed in 2006) of the PubMed database was conducted to identify primary English-language publications of pertinent studies comparing either novel with established regimens of the same bisphosphonates or different established bisphosphonates.

RESULTS

The first option is the equivalence or noninferiority bridging study for comparison of new treatment regimens versus the established regimen of the same bisphosphonate, known as the active comparator. Four such studies have led to the registration of novel bisphosphonate dosing regimens designed to provide easier dosing alternatives for patients. The second option is the active comparator study, which compares one bisphosphonate with the most prescribed weekly bisphosphonate. Weekly dosed oral alendronate has previously been shown to be superior (for bone mineral density gains) to daily and weekly dosed oral risedronate. An ongoing noninferiority study, Monthly Oral Therapy with Ibandronate for Osteoporosis Intervention, is comparing weekly alendronate with ibandronate, a monthly oral bisphosphonate.

CONCLUSIONS

The exploration of new dosing schedules and formulations aims to identify the optimal bisphosphonate regimen for postmenopausal osteoporosis. To achieve this, careful consideration must be given to the choice of a scientifically valid study design that effectively, and ethically, meets the study objectives. Given the concerns regarding placebo-controlled antifracture studies, 2 alternative study designs should be considered, both using validated surrogate end points (bone mineral density and biochemical markers of bone turnover) as the principal mode of assessment.

Once-yearly zoledronic acid for treatment of postmenopausal osteoporosis

BACKGROUND

A single infusion of intravenous zoledronic acid decreases bone turnover and improves bone density at 12 months in postmenopausal women with osteoporosis. We assessed the effects of annual infusions of zoledronic acid on fracture risk during a 3-year period.

METHODS

In this double-blind, placebo-controlled trial, 3889 patients (mean age, 73 years) were randomly assigned to receive a single 15-minute infusion of zoledronic acid (5 mg) and 3876 were assigned to receive placebo at baseline, at 12 months, and at 24 months; the patients were followed until 36 months. Primary end points were new vertebral fracture (in patients not taking concomitant osteoporosis medications) and hip fracture (in all patients). Secondary end points included bone mineral density, bone turnover markers, and safety outcomes.

RESULTS

Treatment with zoledronic acid reduced the risk of morphometric vertebral fracture by 70% during a 3-year period, as compared with placebo (3.3% in the zoledronic-acid group vs. 10.9% in the placebo group; relative risk, 0.30; 95% confidence interval [CI], 0.24 to 0.38) and reduced the risk of hip fracture by 41% (1.4% in the zoledronic-acid group vs. 2.5% in the placebo group; hazard ratio, 0.59; 95% CI, 0.42 to 0.83). Nonvertebral fractures, clinical fractures, and clinical vertebral fractures were reduced by 25%, 33%, and 77%, respectively (P<0.001 for all comparisons). Zoledronic acid was also associated with a significant improvement in bone mineral density and bone metabolism markers. Adverse events, including change in renal function, were similar in the two study groups. However, serious atrial fibrillation occurred more frequently in the zoledronic acid group (in 50 vs. 20 patients, P<0.001).

CONCLUSIONS

A once-yearly infusion of zoledronic acid during a 3-year period significantly reduced the risk of vertebral, hip, and other fractures. (ClinicalTrials.gov number, NCT00049829.)

Bisphosphonates

Bisphosphonates belong to a class of compounds similar to pyrophosphate. In these compounds the oxygen atom of the pyrophosphate is replaced by a carbon atom resulting in a P-C-P bond. They exert a potent inhibitory effect on osteoclasts and are therefore potent antiresorptive agents. They reduce bone turnover, increase bone mineral density, and decrease fracture risk both at the lumbar spine and the hip. Bisphosphonates have a high affinity for bone surfaces, where they accumulate, mainly at sites of bone remodeling. Due to their selectivity in action, they are usually not associated with systemic side effects. Their main unwanted effect is upper gastrointestinal irritation. Alendronate and risedronate are the two most widely used compounds in the treatment of postmenopausal osteoporosis. They are administered orally either daily or once weekly. Ibandronate is a highly potent newer third-generation bisphosphonate administered once monthly with similar efficacy with respect to bone mineral density and fracture risk. Zoledronate, another potent third-generation bisphosphonate, currently approved for the treatment of malignancy-associated hypercalcemia, is currently undergoing phase III trials for the treatment of postmenopausal osteoporosis as an intravenous (i.v.) infusion once annually.

Update in osteoporosis and metabolic bone disorders

Considerable progress has been made in the development and testing of agents to treat osteoporosis. Most impressive are reports on new antiresorptive agents--both bisphosphonates (ibandronate and zoledronic acid) and monoclonal antibodies (MAbs) (denosumab) directed against receptor activator of nuclear factor kappaB-ligand, a key molecule in the control of commitment and activation of osteoclasts. Bisphosphonates promise convenience and potency at slowing bone loss, whereas denosumab offers powerful suppression of resorption and rapid offset of action. Attention is also shifting from the osteoclast as a target for new therapies to the osteoblast and the osteocyte, with its complex network within the depths of bone. Wnt signaling through the frizzled receptor and its coreceptor, the low-density lipoprotein receptor related protein-5, appears from both molecular and in vivo evidence to be a pivotal pathway for modulating osteoblastic activity, bone formation, and bone strength. The recently identified product of the SOST gene or sclerostin has also been shown to block Wnt signaling. Sclerostin is produced by the osteocytes buried in the bone and is a new target to treat bone loss. Clinical trial reports indicate that the calcimimetic cinacalcet can effectively treat PTH hypersecretion due to primary and secondary hyperparathyroidism and parathyroid carcinoma. Lastly, it is now recognized that the matrix protein dentin matrix protein-1 enhances the release of the phosphate-regulating factor fibroblast growth factor 23 and that mutations in dentin matrix protein-1 play a causative role in a form of hypophosphatemic rickets.

Use of intravenous bisphosphonates in osteoporosis

Bisphosphonates, which are potent bone resorption inhibitors, currently are the mainstay of treatment for osteoporosis. Antifracture efficacy has been demonstrated for at least three nitrogen-containing bisphosphonates in oral formulations that are designed to be administered in weekly or monthly dosing regimens. Frequent reports of adverse events, primarily related to the upper gastrointestinal tract, and the strict dosing schedule necessary for oral bisphosphonate therapy are considered the major reasons for disappointing adherence to therapy. New intravenous formulations have been developed that allow dosing at very long intervals, thus avoiding the gastrointestinal complications associated with oral bisphosphonates and, it is hoped, improving compliance, particularly for patients who are intolerant of oral bisphosphonates or have contraindications to their use. This alternative approach holds promise for improved outcomes of osteoporosis treatment and ultimately for reduced health care costs related to caring for people with fragility fractures.

Treatment of Osteoporosis

Osteoporoza je jedna od najčešćih metaboličkih bolesti i zahvaća 8 % do 10 % stanovništva. Budući da je prijelom najteža posljedica osteoporoze, vrlo je važno otkriti bolesnike koji imaju rizik nastanka prijeloma, dati im farmakološku terapiju i savjetovati im promjenu načina života. Nekoliko je lijekova pokazalo sposobnost smanjenja broja prijeloma kralježnice i/ili perifernog skeleta u bolesnika s osteoporozom. Antiresorptivni su lijekovi temelj terapije, ali su i anabolički lijekovi odnedavno proširili mogućnosti liječenja. Antiresorptivni lijekovi, estrogeni, selektivni modulatori estrogenskih receptora, bisfosfonati i kalcitonin, djeluju tako da smanjuju koštanu pregradnju. Paratireoidni hormon potiče novo stvaranje kosti popravljajući arhitekturu i gustoću kosti. Stroncijev ranelat smanjuje rizik osteoporotičnih prijeloma djelujući na oboje - smanjenje razgradnje i povećanje izgradnje kosti. Druga potencijalna liječenja osteoporoze također su opisana u ovome članku.

Tolerability of different dosing regimens of bisphosphonates for the treatment of osteoporosis and malignant bone disease

Bisphosphonates are the primary pharmacological agents used for the management of osteoporosis and hypercalcaemia of malignant bone disease. The efficacy of these agents in these two conditions has been demonstrated in many well designed trials published over the past 2 decades. The variety of bisphosphonates currently available to us provides a wide range of tolerability and dosing profiles thus necessitating a thorough comparison of the most recent oral and intravenous bisphosphonates to differentiate the clinical context in which they should be used. Despite the fact that bisphosphonates are generally well accepted, their tolerability is dependent on complications which encompass gastrointestinal (GI) and renal toxicity. Other adverse events include osteonecrosis of the jaw, arthralgias, flu-like symptoms and uveitis. Studies have shown that various dosing regimens are able to modulate these rates of toxicity. To maximise tolerability, the direction of future therapy will likely fall into a pattern of decreasing the frequency of administration of bisphosphonates, whether it is oral or intravenous formulations, thus improving patient adherence. To review the literature on different dosing regimens of various bisphosphonates and their associated tolerability, we searched MEDLINE for articles from 1975 to 2006. Oral bisphosphonates, in particular alendronate and risedronate, have been systematically evaluated with regards to GI toxicity. Overall tolerability with these oral formulations has found GI toxicity to be the primary adverse event of interest. Both alendronate and risedronate have been found to have similar rates of GI toxicity when compared with placebo. Mounting evidence has developed validating the use of intravenous ibandronate and zoledronic acid for the purpose of treating hypercalcaemia secondary to malignancy. Unique to all other bisphosphonates, ibandronate also has an oral form which has a similar GI-toxicity profile to placebo. In addition, no significant differences in renal toxicity have been observed between those receiving intravenous ibandronate compared with placebo. Because of its potency and mode of administration, zoledronic acid has been widely accepted for the treatment of hypercalcaemia secondary to malignancy. However, a decrease in renal function, albeit rare, remains a significant complication of zoledronic acid; therefore, regular renal monitoring is recommended.

Recent developments in bisphosphonate therapy

OBJECTIVE

To provide a review of current developments in bisphosphonates indicated for the treatment of several rheumatologic conditions, including postmenopausal and glucocorticoid-induced osteoporosis.

METHODS

This review summarizes the pathology, diagnosis, and treatment of both postmenopausal and glucocorticoid-induced osteoporosis and examines the results of current clinical trials of the newest oral and intravenous formulations of nitrogen-containing bisphosphonates. We discuss important adverse events, including upper gastrointestinal symptoms and osteonecrosis of the jaw. Additionally, we explore methods that may improve patient adherence to bisphosphonate therapy, which is currently suboptimal.

RESULTS

Clinical studies have shown that oral bisphosphonates are efficacious in increasing bone mineral density and reducing risk of fracture. Despite concerns of upper gastrointestinal irritation, most of the newer oral bisphosphonates display a safety profile similar to placebo. Many of the newest formulations offer patients a choice in both dosing frequency and method of administration (either oral or intravenous).

CONCLUSIONS

Nitrogen-containing bisphosphonates are important therapeutic options for the prevention and treatment of osteoporosis.

Bone loss and fracture risk associated with cancer therapy

BACKGROUND

Cancer patients experience osteoporosis resulting from accelerated loss of bone mineral density (BMD) caused by their treatment. Such bone loss greatly increases the risk for fracture and can have other serious effects on quality of life.

METHODS

In the current report, the author focuses on studies of cancer therapy-associated bone loss, its prevalence and pathogenesis, and resulting clinical impact. Options for management and prevention are also reviewed, including treatment guidelines where available.

RESULTS

A variety of cancer therapies, including hormonal therapy, chemotherapy, and glucocorticoids, affect gonadal hormone production, which increases bone resorption and decreases BMD. Such bone loss occurs more rapidly and to a greater degree than normal age-related osteoporosis, increases the risk for fracture and other morbidities, and decreases survival. Regular BMD screening and early intervention can prevent further decline in bone density and bone quality. Pharmacologic therapy with oral and i.v. bisphosphonates has been shown to slow bone loss in patients receiving cancer therapy, and the i.v. bisphosphonate zoledronic acid can increase BMD in patients with cancer treatment-related bone loss. Lifestyle changes, including supplementation with calcium and vitamin D, diet, and proper exercise, can also slow the rate of bone loss.

CONCLUSIONS

Bone loss associated with various cancer therapies significantly affects bone health. Early initiation of bisphosphonates, when indicated, and lifestyle modification can improve patient outcomes. Education of patients and health care professionals regarding the importance of this complication and effective treatment options is essential.

Therapy insight: the risks and benefits of bisphosphonates for the treatment of tumor-induced bone disease

Bisphosphonates are a valuable class of drugs with potent anti-resorptive actions that make them ideal for skeletal protection in osteoporosis, cancer bone metastasis, multiple myeloma, and Paget's disease of bone. It has become apparent, however, that these drugs also have the potential to cause a number of adverse effects. While these do not limit bisphosphonate use, the incidence of these adverse events can be minimized if appropriate care is taken with their administration, and by maintaining appropriate surveillance and patient care. We review the range of adverse reactions to bisphosphonate therapy with a particular emphasis on the recently identified association between long-term bisphosphonate treatment and osteonecrosis of the jaw. This is a potentially serious side effect seen mostly in patients with multiple myeloma or breast cancer bone metastases who receive intravenous bisphosphonate treatment. While the etiology is uncertain, a strong association with dental pathology and interventions highlights the need for close attention to dental health in this patient group.

[Bisphosphonates in osteoporosis therapy. Standards and perspectives]

Bisphosphonates are potent inhibitors of bone resorption and approved agents for both the prevention and treatment of osteoporosis. Many clinical studies have shown a consistent reduction in the risk of vertebral fractures with the use of these drugs, while others have shown a clear reduction in the risk of hip and other non-vertebral fractures. The bisphosphonates are divided into three generations based on their potency and chemical structure. In general, as a substance group they are well tolerated and, when applied correctly, the toxicity is low. Alternative dosages, e.g. monthly, three times a month or yearly as an oral drug or i.v. would probably improve patient compliance. Clinical studies have also shown the safety and effectiveness of bisphosphonates over a period of 3-7 years.

Effects of ibandronate on bone quality: preclinical studies

Osteoporosis is a skeletal disorder characterized by low bone mass and deterioration of bone microarchitecture resulting in bone fragility, which increases the risk of fracture. The clinical efficacy of bisphosphonates is evaluated through improvements in bone mineral density (BMD) and reductions in the risk for fracture. However, as bisphosphonates are administered long term, there is increasing interest in their effects on bone quality, which includes bone mass, strength and architecture. Ibandronate is a potent, nitrogen-containing bisphosphonate with significant antifracture efficacy when administered daily and in regimens with extended between-dose intervals. Clinical studies with ibandronate are supported by an extensive preclinical program that investigated the efficacy and bone safety of ibandronate in various animal models of osteoporosis. In preclinical studies, treatment with ibandronate maintained, or improved the quality, strength and architecture of bone. Intermittent and daily ibandronate regimens provided similar benefits. During ibandronate treatment, the bone retains its capacity for repair and bone mineralization is not adversely affected. Notably, positive relationships among BMD, bone strength and bone architecture have been demonstrated. This review describes the preclinical evidence for the preservation of bone quality with ibandronate, irrespective of the dosing regimen and even when administered at doses higher than those used therapeutically.

Intermittent Bisphosphonate Therapy in Postmenopausal Osteoporosis

Bisphosphonates are the most widely prescribed drugs in osteoporosis today. They have unequivocally shown their ability to reduce fracture rate at the spine (alendronic acid, risedronic acid, ibandronic acid) and at the hip (alendronic acid and risedronic acid). However, their dosage and administration procedures and the adverse reactions induced by their oral intake are responsible for low adherence. Therefore, intermittent regimens have been developed. Weekly alendronic acid and risedronic acid provide similar benefits, in terms of bone mineral density (BMD) and changes in biochemical markers, as those seen with their daily formulations. Ibandronic acid has been shown to reduce vertebral fractures when given intermittently. Ibandronic acid given orally monthly and intravenously every 2 or 3 months provides increases in BMD similar to the daily formulation. Yearly intravenous infusions of zoledronic acid are currently being evaluated for their ability to reduce fractures. If the efficacy and safety of bisphosphonates given at administration intervals longer than weekly are confirmed, this might significantly improve patient adherence and long-term outcomes of bisphosphonate treatment in postmenopausal osteoporosis.

Medication persistence with weekly versus daily doses of orally administered bisphosphonates

OBJECTIVE

To compare medication persistence among patients receiving daily orally administered bisphosphonates with persistence among patients receiving weekly orally administered bisphosphonates to ascertain whether less frequent dosing is associated with better long-term treatment persistence.

METHODS

A large, longitudinal cohort of female patients (N = 211,319) receiving prescriptions for alendronate or risedronate from approximately 14,000 US retail pharmacies was assessed. Medication persistence was defined as the percentage of patients who continued to take bisphosphonate therapy during each month (that is, having at least 1 day of medication supply in that month) for a 1-year observation period.

RESULTS

The inconvenience and complexity of required dosing procedures with oral bisphosphonate therapy for the prevention and treatment of osteoporosis are thought to be major factors that hinder medication persistence, and poor persistence is associated with suboptimal health-care outcomes. In this study, the percentage of patients continuing to take bisphosphonate therapy steadily declined with both daily and weekly oral treatment regimens during the course of the 12-month observation period. Consistently, however, medication persistence was higher among patients receiving the weekly rather than the daily regimen. Only 56.7% of patients receiving the weekly regimen and only 39.0% of patients receiving the daily regimen continued to take bisphosphonate therapy at month 12 of the study period (P<0.0001).

CONCLUSION

This study demonstrates that weekly dosing of orally administered bisphosphonates is associated with higher medication persistence than is daily dosing. Nevertheless, more than 40% of patients did not persist with weekly bisphosphonate therapy for at least 12 months. Thus, medication persistence was inadequate even with use of the weekly regimen. Additional research is needed to determine whether persistence can be further improved by extending the dosing interval beyond once weekly.

Treating osteoporosis with bisphosphonates and addressing adherence: a review of oral ibandronate

Osteoporosis is a common, chronic condition, affecting approximately half of all postmenopausal Caucasian women in the US. Vertebral fractures occur as a result of osteoporosis and lead to increased hospitalisation and mortality, and adversely affect patient quality of life. The burden of osteoporosis on healthcare systems is expected to rise as the elderly population continues to grow. Yet there are many medications for preventing and treating osteoporosis. Oral bisphosphonates are first-line treatment for osteoporosis, with demonstrated efficacy in increasing bone mineral density and reducing bone turnover, which reduces the incidence of fractures. However, adherence to medication is suboptimal, with approximately 40% of patients discontinuing treatment within 6 months. Recent reports have suggested simplifying the dosage regimen as a strategy to help address this issue. Ibandronate is a potent, nitrogen-containing bisphosphonate which is administered once-monthly. Preclinical studies initially revealed the feasibility of extending the between-dose interval. Subsequent clinical studies have provided further evidence of the positive effects of extended-interval ibandronate administration in reducing the risk of vertebral fractures through increasing bone mineral density and reducing bone turnover without compromising bone quality. These studies have also demonstrated that ibandronate has a safety profile similar to placebo. Ibandronate has recently been approved for use in the US to treat postmenopausal osteoporosis. This review summarises the efficacy and safety of once-monthly oral ibandronate and discusses the implications of such a treatment in primary care in the US.

Osteoporosis update: effective prevention and treatment

Osteoporosis is a public health threat to approximately 44 million individuals in the USA, or 55% of men and women over the age of 50 years. The primary goal of osteoporosis management is to prevent fracture, the most devastating consequence. Risk factors and bone mineral density can be assessed to determine appropriate action for prevention and treatment of osteoporosis. Prevention strategies include lifestyle modification, fall prevention, and adequate intake of calcium and vitamin D. Current treatment options include antiresorptive agents and anabolic agents. Adherence and cost issues play major roles in establishing optimal therapy for individual patients. New agents in development are designed to improve osteoporosis treatment and patient adherence. This review focuses on current and future prevention and treatment options for postmenopausal osteoporosis.

Drug insight: Bisphosphonates for postmenopausal osteoporosis

Bisphosphonates are potent antiresorptive agents, which have largely been used for the treatment of postmenopausal osteoporosis during the past 10 years. When embedded in bone matrix, bisphosphonates are taken up by osteoclasts engaged in bone resorption, leading--mainly by inhibition of farnesyl diphosphate synthase, a key enzyme of the mevalonate pathway--to osteoclast apoptosis. Bone resorption decreases, with consequent improvement in the mechanical properties of bone and a reduced risk of fracture. Alendronate and risedronate are oral nitrogen-containing bisphosphonates. Several randomized, placebo-controlled trials have shown the ability of these bisphosphonates to halve the risk of vertebral fracture when taken daily for 3 years. Nonvertebral fracture risk, including that at the hip, was also significantly decreased. Weekly regimens have simplified the administration of bisphosphonates and, probably, improved adherence to treatment. A significant reduction in the risk of vertebral fracture has also been demonstrated with an intermittent regimen of ibandronate, which is a new, potent, nitrogen-containing bisphosphonate. Ibandronate was recently marketed for use in an oral, once-monthly dose of 150 mg, with the goal of improving compliance. Bisphosphonates are usually well tolerated in the long term. Intravenous administration of bisphosphonates in women with osteoporosis, which is currently under investigation, might be an interesting future option for women who cannot tolerate oral regimens, and for enhancing compliance.

DVO-Leitlinie 2006

The main changes in the updated DVO guideline 2006 on prevention, diagnosis and treatment of osteoporosis in postmenopausal women and in older men concern the evaluation of individual fracture risks and the selection of medicamentous therapy by means of new thresholds. A 30% risk of osteoporotic vertebral or hip fracture per decade is recommended as the threshold for implementation of pharmacological therapy. Evaluation of the individual absolute fracture risk is based on a combination of the results of densitometry at the lumbar spine and femur, age, gender, and other risk factors that are specifically associated with osteoporosis. Patient's mobility is assessed by carrying out special mobility tests. Further changes seen in the 2006 update of the DVO guideline are therapy proposals taking account of new pharmaceutical developments. New effective medications are rh-PTH (1-34), or teriparatide, strontium ranelate, and ibandronate (bisphosphonate) for monthly oral administration. Minimally invasive operative techniques for use in vertebral fractures in combination with medicamentous antiosteoporosis therapy are also included in the 2006 update of the DVO guideline. Thus, in the 2006 update of the DVO-guideline we have a practice-oriented 53 guideline that is adapted to individual fracture risk and gives recommendations on the prevention, diagnosis and treatment of osteoporosis.

Treatment persistence with once-monthly ibandronate and patient support vs. once-weekly alendronate: results from the PERSIST study

Osteoporosis is a common and debilitating condition associated with significant morbidity and mortality. The efficacy and safety of oral bisphosphonates for the treatment of osteoporosis are well established. However, patient adherence and persistence on treatment are suboptimal. This randomised open-label multi-centre study of 6-months' duration compared persistence on treatment in postmenopausal women with osteoporosis receiving either once-monthly ibandronate plus a patient support programme (PSP), or once-weekly alendronate. To avoid falsely elevated persistence rates often associated with clinical trials, the study was designed to reflect everyday clinical practice in the UK and follow-up visits were limited to be consistent with the primary care setting. Analysis of the primary endpoint showed that persistence was significantly higher in the ibandronate/PSP group compared with the alendronate group (p < 0.0001). The estimated proportion of patients persisting with treatment at 6 months was 56.6% (306/541) and 38.6% (198/513) in the ibandronate/PSP and alendronate groups, respectively. Therefore, compared with alendronate, there was a 47% relative improvement in the proportion of patients persisting with treatment in the ibandronate/PSP group. Secondary endpoint measurements of adherence (e.g. proportion of patients remaining on treatment at study end; proportion of patients discontinuing from the study) were also significantly different in favour of ibandronate plus patient support. In summary, the PERSIST study demonstrated that persistence on treatment was increased in patients receiving once-monthly ibandronate plus patient support compared with once-weekly alendronate. Increased persistence on bisphosphonate treatment is expected to improve patient outcomes and decrease the social and economic burden of osteoporosis.

Intravenous ibandronate injections in postmenopausal women with osteoporosis: one-year results from the dosing intravenous administration study

OBJECTIVE

Although oral bisphosphonates are effective treatments for postmenopausal women with osteoporosis, oral dosing may be unsuitable for some patients. An efficacious intravenously administered bisphosphonate could be beneficial for such patients. Ibandronate, a potent nitrogen-containing bisphosphonate, can be administered using extended dosing intervals, either orally or by rapid intravenous injection. The aim of this study was to identify the optimal intravenous dosing regimen for ibandronate in postmenopausal women with osteoporosis.

METHODS

In a randomized, double-blind, double-dummy, phase III, noninferiority study, we compared 2 regimens of intermittent intravenous injections of ibandronate (2 mg every 2 months and 3 mg every 3 months) with a regimen of 2.5 mg of oral ibandronate daily, the latter of which has proven antifracture efficacy. The study group comprised 1,395 women (ages 55-80 years) who were at least 5 years postmenopausal. All patients had osteoporosis (lumbar spine [L2-L4] bone mineral density [BMD] T score less than -2.5). Participants also received daily calcium (500 mg) and vitamin D (400 IU). The primary end point was change from baseline in lumbar spine BMD at 1 year. Changes in hip BMD and in the level of serum C-telopeptide of type I collagen (CTX) were also measured, as were safety and tolerability.

RESULTS

At 1 year, mean lumbar spine BMD increases were as follows: 5.1% among 353 patients receiving 2 mg of ibandronate every 2 months, 4.8% among 365 patients receiving 3 mg of ibandronate every 3 months, and 3.8% among 377 patients receiving 2.5 mg of oral ibandronate daily. Both of the intravenous regimens not only were noninferior, but also were superior (P < 0.001) to the oral regimen. Hip BMD increases (at all sites) were also greater in the groups receiving medication intravenously than in the group receiving ibandronate orally. Robust decreases in the serum CTX level were observed in all arms of the study. Both of the intravenous regimens were well tolerated and did not compromise renal function.

CONCLUSION

As assessed by BMD, intravenous injections of ibandronate (2 mg every 2 months or 3 mg every 3 months) are at least as effective as the regimen of 2.5 mg orally daily, which has proven antifracture efficacy, and are well tolerated.

Osteoporosis

Osteoporosis is a serious public health issue. The past 10 years have seen great advances in our understanding of its epidemiology, pathophysiology, and treatment, and further advances are rapidly being made. Clinical assessment will probably evolve from decisions mainly being made on the basis of bone densitometry, to use of algorithms of absolute fracture risk. Biochemical markers of bone turnover are also likely to become more widely used. Bisphosphonates will probably remain the mainstay of therapy, but improved understanding of the optimum amount of remodelling suppression and duration of therapy will be important. At the same time, other diagnostic and therapeutic approaches, including biological agents, are likely to become more widespread.

Update of current therapeutic options for the treatment of postmenopausal osteoporosis

BACKGROUND

Osteoporosis is a common chronic condition in elderly women and is associated with decreased bone strength and an increased risk for fractures. As the incidence of osteoporotic fractures continues to rise, it is important to identify the most effective therapies for reducing patients' risk of fracture.

OBJECTIVE

This article reviews the medication classes commonly used for treating osteoporosis and the efficacy, tolerability, and drug-interaction potential of specific medications. The evidence for the use of combination therapies is summarized, as are the agents under investigation.

METHODS

Relevant articles were identified through a search of MEDLINE (August 1985-August 2005) using the terms osteoporosis, postmenopausal, fracture, and efficacy combined with drug therapy, calcium, vitamin D, estrogen, progesterone, selective estrogen modulators, calcitonin, strontium ranelate, bisphosphonates, alendronate, risedronate, ibandronate, pamidronate, parathyroid hormone, combination therapy, and zoledronic acid. The identified articles were reviewed for suitability, with priority given to meta-analyses.

RESULTS

Among the therapeutic options for the treatment of osteoporosis, the bisphosphonates appear to provide the greatest antiresorptive efficacy, with some bisphosphonates providing 7% to 8% increases in bone mineral density and 60% to 70% decreases in markers of bone resorption. Bisphosphonates also may reduce the incidence of new vertebral fractures by 50% to 52%.

CONCLUSIONS

Bisphosphonates are currently the first choice for the treatment of osteoporosis. Use of intermittent regimens of the newer bisphosphonates appears to be a promising alternative to administration of daily or weekly treatment.

Less frequent dosing of bisphosphonates in osteoporosis: focus on ibandronate

BACKGROUND

Bisphosphonates form the mainstay of treatment in osteoporosis; however, current adherence with therapy is inadequate. Problems with adherence are thought to be linked to several factors, including frequency of dosing and bisphosphonate-associated intolerability. For non adherent patients, less frequent dosing may be desirable, because the frequency with which strict and inconvenient dosing procedures must be followed is reduced.

OBJECTIVES

A new nitrogen-containing bisphosphonate, ibandronate, offers sustained efficacy, with an extended between-dose interval. The molecular characteristics of ibandronate that support extended dosing are described, and trial outcomes for oral and intravenous ibandronate are summarized, in the context of other available bisphosphonates, based on the results of a search of MEDLINE publications (January 1975-December 2005). Relevant safety issues are discussed.

CONCLUSION

Awareness of the scientific basis, published trial findings, and clinical implications associated with a once-monthly bisphosphonate can guide treatment decisions and inform communications with patients.

Ibandronate: a new oral bisphosphonate for postmenopausal osteoporosis

OBJECTIVE

To review a new oral bisphosphonate, ibandronate, recently approved by the U.S. Food and Drug Administration for the treatment and prevention of postmenopausal osteoporosis.

DATA SOURCE

A MEDLINE/PUBMED search was conducted to identify pertinent studies in the English language. Additional references were obtained from the bibliographies of these studies. Data over the time period of 1986 through July 2005 were reviewed.

STUDY SELECTION AND DATA EXTRACTION

All studies evaluating any aspect of ibandronate in animals and humans. Studies in humans focused on the oral drug formulation.

DATA SYNTHESIS

Preclinical studies established that ibandronate was an extremely potent bisphosphonate compared with its predecessors and that it was active in all animal models of human postmenopausal and corticosteroid-associated osteoporosis. Similar to other selected bisphosphonates, preclinical studies also showed that ibandronate exhibits antitumor activity and prevents and/or reduces bone metastases. As with other oral bisphosphonates, oral bioavailability is very poor (less than 1%) and substantially reduced by administration with or proximal to cations (e.g., food, antacids, mineral supplements). Clinical trials have demonstrated the efficacy and tolerability of oral ibandronate in the treatment and prevention of postmenopausal osteoporosis when administered once daily, once weekly, and even once monthly. Ibandronate also reduces the skeletal complications of bone metastases in patients with cancer, including pain, although the dosage used is much higher than that used in osteoporosis. As with other bisphosphonates, the major tolerability issue with ibandronate is upper gastrointestinal (GI) distress (dyspepsia, pain, esophagitis, esophageal and gastric ulcers). The dosage regimen for the treatment or prevention of postmenopausal osteoporosis (the only currently approved use in the United States) is 2.5 mg once a day or 150 mg once monthly (on the same date each month). Ibandronate should not be used in the presence of severe renal impairment (creatinine clearance below 30 mL/min). The usual complex administration instructions for other oral bisphosphonates apply to ibandronate as well.

CONCLUSION

Oral ibandronate is an interesting addition to the therapeutic armamentarium for osteoporosis and cancer metastatic to bone. In fact, studies of ibandronate as an adjunctive treatment for cancers with a predilection to metastasize to bone are under way. Ibandronate has taken advantage of a complex pharmacodynamic profile in which its antiresorptive activity is independent of the frequency of dosing provided that a minimum dose-per-unit time is exceeded. Studies with every three-month dosing (and even less frequently) are under way. Whether or not the less frequent dosing of oral ibandronate will translate into a therapeutic advantage over older oral agents such as alendronate and risedronate is open to speculation. This is a difficult question to answer in the absence of head-to-head randomized controlled trials (RCTs). Older agents are still preferred until RCTs demonstrate that ibandronate is as safe and effective as these older agents.

Management of osteoporosis in postmenopausal women

OBJECTIVE

To update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2002 regarding the management of osteoporosis in postmenopausal women.

DESIGN

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 were enlisted to review the 2002 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, whose prevalence is especially high among elderly 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, a selective estrogen-receptor modulator, parathyroid hormone, estrogens, and calcitonin.

CONCLUSIONS

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

Ibandronate: once-monthly and intravenous dosing options for osteoporosis treatment

Ibandronate is a potent nitrogen-containing bisphosphonate that is currently available as a daily and once-monthly oral formulation for the treatment and prevention of osteoporosis. It has recently been approved for intermittent intravenous administration. The oral iBandronate Osteoporosis vertebral fracture trial in North America and Europe (BONE), Monthly Oral iBandronate In LadiEs (MOBILE), and Dosing IntraVenous Administration (DIVA) trials demonstrated that long-term daily and intermittent administration of ibandronate was efficacious for increasing bone mineral density and reducing markers of bone turnover. BONE demonstrated that ibandronate reduced the risk of new vertebral fractures and reduced the relative risk of nonvertebral fractures in higher-risk patients. Histomorphometric evaluations in the BONE and DIVA trials have demonstrated that bone quality is maintained following treatment. Giving patients the option of choosing their dose regimen and route of administration may increase overall adherence to treatment, leading to enhanced fracture protection in patients with osteoporosis.

Once-monthly dosing: an effective step forward

To improve upon the currently suboptimal level of therapeutic adherence with bisphosphonates in postmenopausal osteoporosis, there is a need to examine less-frequently dosed regimens that offer patients greater convenience than weekly dosing. Ibandronate is a potent, nitrogen-containing bisphosphonate specifically developed for administration with long between-dose intervals. It has proven antifracture efficacy when administered orally, daily or intermittently (>2 months dose-free interval) and a safety profile comparable with placebo. A dose-ranging study evaluating a simplified once-monthly ibandronate dosing schedule confirmed the feasibility of the regimen. Significant decreases from baseline in the biochemical markers of bone turnover, serum and urinary C-telopeptide of the alpha-chain of type 1 collagen (CTX) were observed for all once-monthly doses assessed. An analysis of the area under the effect curve for these two parameters confirmed a dose-response relationship. The MOBILE study was a large (n = 1609), randomized, double-blind, non-inferiority study comparing three doses of monthly oral ibandronate (50 + 50 mg, 100 mg and 150 mg) with daily oral ibandronate (2.5 mg) in women with postmenopausal osteoporosis. Analyses have been completed at the end of 1 and 2 years of treatment. With substantial increases in lumbar spine bone mineral density (BMD; 5.3-6.6%), all of the once-monthly regimens were non-inferior, and, in addition, the 150 mg regimen was superior (P < or = 0.002) to the daily regimen. Corresponding increases in BMD were also observed at all hip sites. The greatest gains in lumbar spine, and hip BMD were consistently seen with the 150 mg regimen. Considerable reductions in serum CTX were seen with all regimens from 3 months onwards (50.0-66.4%); these reductions were maintained throughout the 2-year period (2 years: 56.1-67.7%). The safety profile of the once-monthly regimens was comparable with the daily regimen throughout the 2 years. Once-monthly ibandronate is an effective and well-tolerated treatment for patients with postmenopausal osteoporosis. Given the recently reported strong patient preference for once-monthly regimens and the impact of patient preference on therapeutic adherence, it is anticipated that once-monthly ibandronate will offer patients an alternative convenient regimen that may improve adherence over weekly bisphosphonates and should enhance outcomes.

Once-monthly Ibandronate for postmenopausal Osteoporosis: Review of a new dosing regimen

BACKGROUND

Ibandronate, a nitrogen-containing bisphosphonate, was approved by the US Food and Drug Administration (FDA) in May 2003 as a daily oral regimen for the treatment and prevention of post-menopausal osteoporosis. In March 2005, the FDA approved once-monthly dosing with ibandronate for the same indications.

OBJECTIVE

The purpose of this article was to review the efficacy and tolerability of ibandronate 150 mg once monthly in the treatment and prevention of post-menopausal osteoporosis.

METHODS

A search of MEDLINE (1966-September 2005) and International Pharmaceutical Abstracts (1971-September 2005) for articles relating to the efficacy and tolerability of once-monthly ibandronate in the treatment of postmenopausal osteoporosis was conducted using the terms ibandronate and ibandronic acid. Additional searches were conducted to identify publications relevant to compliance and pharmacoeconomic considerations using the terms bispbospbonate, compliance, cost, and pharmacoeconomics. The reference lists of identified articles and presentations from recent scientific meetings also were reviewed. Selected safety information from the manufacturer was incorporated.

RESULTS

Ibandronate 2.5 mg/d and intermittent ibandronate (20 mg QOD for 12 doses every 3 months) have been shown to effectively reduce the incidence of vertebral fractures; after 3 years of therapy in a placebo-controlled clinical trial, the relative risk reductions for new vertebral fractures with daily and intermittent ibandronate were 62% and 50%, respectively (both, P<0.001 vs placebo). Once-monthly ibandronate has been evaluated in 2 clinical trials: a Phase I dose-ranging trial in 144 healthy postmenopausal women and a Phase III noninferiority trial in 1609 women with postmenopausal osteoporosis who were randomized to receive ibandronate 2.5 mg/d or 1 of 3 monthly ibandronate regimens: 50/50 mg (50 mg given on 2 consecutive days) once monthly; 100 mg once monthly; and 150 mg once monthly. The primary end point of the Phase III trial was the change from baseline in lumbar spine bone mineral density (BMD). After 1 year of therapy, patients who received ibandronate 150 mg once monthly had a significantly greater increase from baseline in lumbar spine BMD compared with those who received ibandronate 2.5 mg/d (4.9% vs 3.9%, respectively; P=0.002). The overall adverse-event profile was similar between the daily and monthly regimens. Drug-related adverse events were reported in 32.4% of patients receiving ibandronate 2.5 mg/d and 36.9% of patients receiving ibandronate 150 mg monthly. Upper gastrointestinal adverse events occurred in a respective 22.8% and 22.5% of the 2 groups. After 1 year of therapy, patients receiving ibandronate 150 mg monthly reported more flulike symptoms (8.3%) compared with those receiving ibandronate 2.5 mg/d (2.8%). In a crossover study comparing preference for and convenience of monthly ibandronate and weekly alendronate in 342 ambulatory women with postmenopausal osteoporosis, significantly more patients preferred the monthly ibandronate regimen to the weekly alendronate regimen (71.4% vs 28.5%, respectively; P<0.001).

CONCLUSION

Once-monthly ibandronate is an effective and well-tolerated treatment option for postmenopausal osteoporosis.

Improving compliance and persistence with bisphosphonate therapy for osteoporosis

The successful treatment of patients at increased risk for fracture requires proper diagnosis and the development of a treatment plan that permits the patient to take medications in accordance with dosing guidelines and on the correct schedule. Data indicate that patients with osteoporosis who have good long-term medication compliance experience substantially lower risk of fracture. Persistence with therapy also correlates with better bone mineral density and improved suppression of bone turnover markers. Although bisphosphonates are the most potent currently approved antiresorptive agents, they have special dosing issues that can have a negative impact on long-term persistence. The inconvenience and complexity of some dosing requirements; the potential for adverse effects, especially when dosing recommendations are not followed; and very low absorption rates--even under ideal conditions--all contribute to poor outcomes. Extension of the dosing interval from a once-daily to a once-weekly regimen is associated with comparable efficacy, theoretically may improve gastrointestinal safety, and is associated with substantial improvement in persistence with therapy. However, compliance with weekly regimens remains suboptimal. Monthly dosing of ibandronate, a bisphosphonate, was recently approved by the US Food and Drug Administration (FDA). Although extending the dosing interval may improve compliance and persistence with bisphosphonate therapy, it is important to recognize that missed doses or improper dosing may have greater consequences with extended dosing intervals. This article highlights the importance of educating patients about their diagnosis and long-term treatment plan, including the importance of persistence with therapy and compliance with dosing recommendations.

Beyond daily dosing: clinical experience

Osteoporosis has had a significant public health impact, with many sufferers experiencing fractures. Such fractures lead to increased disability, mortality and reduced quality of life, all of which raise healthcare costs. Oral bisphosphonates are associated with significant antifracture efficacy and have therefore become the mainstay of treatment for postmenopausal osteoporosis. Poor therapeutic adherence with daily bisphosphonates has been improved by the introduction of weekly regimens, although adherence levels remain suboptimal. Bisphosphonate regimens with dosing intervals beyond a week have therefore been developed to address this issue. Oral ibandronate, a potent nitrogen-containing bisphosphonate, has been studied using daily and intermittent regimens (between-dose interval >2 months). The initial phase II 2-year study confirmed the feasibility of the intermittent regimen, providing increases in lumbar spine bone mineral density (BMD) superior to placebo (P < 0.01) and equivalent to the daily regimen (5.64% vs. 5.54%, respectively). BONE (Oral iBandronate Osteoporosis vertebral fracture trial in North America and Europe), a large phase III 3-year study was subsequently initiated, including 2946 women with postmenopausal osteoporosis and testing both a daily as well as an intermittent regimen with a dose-free interval of more than 2 months. Significant vertebral antifracture efficacy (the primary study endpoint) was demonstrated with daily (2.5 mg) and intermittent (20 mg every other day for 12 doses every 3 months) ibandronate in comparison with placebo (P < or = 0.0006). As a result of the study not being designed and powered to show an effect on non-vertebral fractures and the overall population being at low risk for osteoporotic fractures, differences in the incidence of non-vertebral fractures were similar between groups (8.2-9.1%) However, a post hoc analysis in a subgroup of patients with a femoral neck BMD T-score < -3.0 showed that daily ibandronate significantly reduced the risk of non-vertebral fractures (P = 0.012). Both regimens were associated with significant increases in lumbar spine and proximal femur BMD and normalization of bone turnover. As determined by adverse event incidence and laboratory evaluation, the safety profile for both ibandronate regimens was similar to that observed for placebo. The BONE study therefore confirmed that daily or intermittent ibandronate is an effective and well-tolerated treatment for postmenopausal women. Being the first study to demonstrate antifracture efficacy with an intermittent regimen, it provided "proof of concept" for beyond weekly dosing with ibandronate and prompted further development of a more convenient once-monthly regimen.

Modeling of Serum C-Telopeptide Levels with Daily and Monthly Oral Ibandronate in Humans

A previously validated kinetic-pharmacodynamic model was applied to changes in a marker of bone resorption (serum C-telopeptide cross-links of type I collagen [sCTX]) using data from a large-scale clinical trial of ibandronate (Monthly Oral iBandronate In LadiEs [MOBILE]). The model showed rapid and significant suppression of sCTX compared to baseline with daily and monthly ibandronate, and gradual recovery of sCTX levels between monthly doses. This modeled, post-dose oscillatory pattern of sCTX paralleled significant increases in BMD and was associated with an acceptable safety profile for patients in MOBILE, suggesting that the between-dose recovery of sCTX does not negatively affect the efficacy of once-monthly ibandronate.

Ibandronate treatment for osteoporosis: rationale, preclinical, and clinical development of extended dosing regimens

Ibandronate is a potent nitrogen-containing bisphosphonate available as a once-monthly oral formulation for the treatment and prevention of osteoporosis. Preclinical experiments with estrogen-depleted rats, dogs, and monkeys demonstrated the efficacy of daily and intermittent ibandronate dosing. Initial clinical trials explored the optimal dosing regimens for oral administration in humans. The Oral Ibandronate Osteoporosis Vertebral Fracture Trial in North America and Europe (BONE) and Monthly Oral Ibandronate in Ladies (MOBILE) trials demonstrated that long-term daily and intermittent administration of ibandronate was efficacious for increasing bone mineral density, reducing markers of bone turnover, and preventing fractures, while maintaining bone quality. These preclinical and clinical ibandronate trials provided progressive evidence that a simple, long interval dosing regimen could offer efficacy and safety comparable with currently available bisphosphonates. It is anticipated that once-monthly ibandronate may have a positive impact on patient adherence, and ultimately, on fracture protection in osteoporotic women.

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

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

Efficacy and tolerability of once-monthly oral ibandronate in postmenopausal osteoporosis: 2 year results from the MOBILE study

BACKGROUND

Reducing bisphosphonate dosing frequency may improve suboptimal adherence to treatment and therefore therapeutic outcomes in postmenopausal osteoporosis. Once-monthly oral ibandronate has been developed to overcome this problem.

OBJECTIVE

To confirm the 1 year results and provide more extensive safety and tolerability information for once-monthly dosing by a 2 year analysis.

METHODS

MOBILE, a randomised, phase III, non-inferiority study, compared the efficacy and safety of once-monthly ibandronate with daily ibandronate, which has previously been shown to reduce vertebral fracture risk in comparison with placebo.

RESULTS

1609 postmenopausal women were randomised. Substantial increases in lumbar spine bone mineral density (BMD) were seen in all treatment arms: 5.0%, 5.3%, 5.6%, and 6.6% in the daily and once-monthly groups (50 + 50 mg, 100 mg, and 150 mg), respectively. It was confirmed that all once-monthly regimens were at least as effective as daily treatment, and in addition, 150 mg was found to be better (p<0.001). Substantial increases in proximal femur (total hip, femoral neck, trochanter) BMD were seen; 150 mg produced the most pronounced effect (p<0.05 versus daily treatment). Independent of the regimen, most participants (70.5-93.5%) achieved increases above baseline in lumbar spine or total hip BMD, or both. Pronounced decreases in the biochemical marker of bone resorption, sCTX, observed in all arms after 3 months, were maintained throughout. The 150 mg regimen consistently produced greater increases in BMD and sCTX suppression than the 100 mg and daily regimens. Ibandronate was well tolerated, with a similar incidence of adverse events across groups.

CONCLUSIONS

Once-monthly oral ibandronate is at least as effective and well tolerated as daily treatment. Once-monthly administration may be more convenient for patients and improve therapeutic adherence, thereby optimising outcomes.