Teriparatide in the treatment of osteoporosis

FDA's stamp of approval: Unveiling peptide breakthroughs in cardiovascular diseases, ACE, HIV, CNS, and beyond

Peptides exhibit significant specificity and effective interaction with therapeutic targets, positioning themselves as key players in the global pharmaceutical market. They offer potential treatments for a wide range of diseases, including those that pose significant challenges. Notably, the peptide trofinetide (Daybue) marked a groundbreaking achievement by providing the first-ever cure for Rett syndrome, and several peptides have secured FDA approval as first-in-class medications. Furthermore, peptides are expanding their presence in areas traditionally dominated by either small or large molecules. A noteworthy example is the FDA approval of motixafortide (Aphexda) as the first peptide-based chemokine antagonist. Here, the focus will be on the analysis of FDA-approved peptides, particularly those targeting cardiovascular diseases, human immunodeficiency, central nervous system diseases, and various other intriguing classes addressing conditions such as osteoporosis, thrombocytopenia, Cushing's disease, and hypoglycemia, among others. The review will explore the chemical structures of the peptides, their indications and modes of action, the developmental trajectory, and potential adverse effects.

Current Status of the Diagnosis and Management of Osteoporosis

Osteoporosis has been defined as the silent disease of the 21st century, becoming a public health risk due to its severity, chronicity and progression and affecting mainly postmenopausal women and older adults. Osteoporosis is characterized by an imbalance between bone resorption and bone production. It is diagnosed through different methods such as bone densitometry and dual X-rays. The treatment of this pathology focuses on different aspects. On the one hand, pharmacological treatments are characterized by the use of anti-resorptive drugs, as well as emerging regenerative medicine treatments such as cell therapies and the use of bioactive hydrogels. On the other hand, non-pharmacological treatments are associated with lifestyle habits that should be incorporated, such as physical activity, diet and the cessation of harmful habits such as a high consumption of alcohol or smoking. This review seeks to provide an overview of the theoretical basis in relation to bone biology, the existing methods for diagnosis and the treatments of osteoporosis, including the development of new strategies.

Common osteoporosis drug associated with increased rates of depression and anxiety

Osteoporosis affects over 10 million Americans over 50. Bisphosphonate therapy, mainly alendronate, is amongst the most prescribed treatments for the disease. The use of alendronate and other bisphosphonates has been associated with depressive symptoms in recent case reports. In this study we quantified this association by analyzing over 100,000 adverse events reports from the Food and Drug Administration Adverse Events Reporting System (FAERS) and the World Health Organization’s (WHO) global database for adverse drug reactions, ADRs, VigiAccess. We found that alendronate therapy is significantly associated with depression and anxiety when compared to other first-line osteoporosis treatments. The reported risk of depressive ADRs was found to be over 14-fold greater in patients taking alendronate under the age of 65 and over fourfold greater for patients over 65 compared to the control. Several hypotheses concerning the molecular mechanism of the observed association of alendronate and depressive symptoms were discussed.

Lactate Dehydrogenase Inhibition With Oxamate Exerts Bone Anabolic Effect

Cellular bioenergetics is a promising new therapeutic target in aging, cancer, and diabetes because these pathologies are characterized by a shift from oxidative to glycolytic metabolism. We have previously reported such glycolytic shift in aged bone as a major contributor to bone loss in mice. We and others also showed the importance of oxidative phosphorylation (OxPhos) for osteoblast differentiation. It is therefore reasonable to propose that stimulation of OxPhos will have bone anabolic effect. One strategy widely used in cancer research to stimulate OxPhos is inhibition of glycolysis. In this work, we aimed to evaluate the safety and efficacy of pharmacological inhibition of glycolysis to stimulate OxPhos and promote osteoblast bone-forming function and bone anabolism. We tested a range of glycolytic inhibitors including 2-deoxyglucose, dichloroacetate, 3-bromopyruvate, and oxamate. Of all the studied inhibitors, only a lactate dehydrogenase (LDH) inhibitor, oxamate, did not show any toxicity in either undifferentiated osteoprogenitors or osteoinduced cells in vitro. Oxamate stimulated both OxPhos and osteoblast differentiation in osteoprogenitors. In vivo, oxamate improved bone mineral density, cortical bone architecture, and bone biomechanical strength in both young and aged C57BL/6J male mice. Oxamate also increased bone formation by osteoblasts without affecting bone resorption. In sum, our work provided a proof of concept for the use of anti-glycolytic strategies in bone and identified a small molecule LDH inhibitor, oxamate, as a safe and efficient bone anabolic agent. © 2020 American Society for Bone and Mineral Research (ASBMR).

Conducting an observational study during an economic crisis: analysis of the treatment and follow-up phase of Greek patients participating in the ExFOS study

OBJECTIVE

We present the subanalysis of the Greek cohort of the Extended Forsteo Observational Study (ExFOS), a multicenter, non-interventional, prospective, observational study evaluating the effect of teriparatide on fractures, back pain (BP), health-related quality of life (HR-QoL), and safety and compliance, in patients with osteoporosis treated for up to 24 months, with a post-treatment follow-up of at least 18 months.

DESIGN

A total of 439 osteoporotic patients (92.2% female) were enrolled in Greece. New or worsened fractures, based on their physicians' assessment, as well as patients' self-assessment of HR-QoL and BP, compliance, and safety profile, were captured by validated questionnaires.

RESULTS

In the ExFOS Greek cohort, fracture rates were low and mean bone mineral density (BMD) was numerically improved. Compliance with teriparatide remained high throughout the study, with 81.5% of subjects completing treatment. Only 0.7% of patients reported discontinuation due to adverse effects. A sustainable improvement in patient-perceived BP and HRQoL throughout treatment and follow-up was similar to that achieved by the European Forsteo Observational Study (EFOS). A lower than expected percentage of patients using antiresorptives following teriparatide was recorded.

CONCLUSIONS

ExFOS reproduces the outcomes of EFOS, with a 6.5-year time interval between studies, in comparable cohorts of osteoporotic patients. Data should be interpreted in the context of observational study data collection, although summary statistics computed at each time point may overstate drug effect.

Concise Review: Musculoskeletal Stem Cells to Treat Age-Related Osteoporosis

Age‐related (type‐II) osteoporosis is a common and debilitating condition driven in part by the loss of bone marrow (BM) mesenchymal stromal cells (MSC) and their osteoblast progeny, leading to reduced bone formation. Current pharmacological regiments targeting age‐related osteoporosis do not directly treat the disease by increasing bone formation, but instead use bisphosphonates to reduce bone resorption—a treatment designed for postmenopausal (type‐I) osteoporosis. Recently, the bone regenerative capacity of MSCs has been found within a very rare population of skeletal stem cells (SSCs) residing within the larger heterogeneous BM‐MSC pool. The osteoregenerative potential of SSCs would be an ideal candidate for cell‐based therapies to treat degenerative bone diseases such as osteoporosis. However, to date, clinical and translational studies attempting to improve bone formation through cell transplantation have used the larger, nonspecific, MSC pool. In this review, we will outline the physiological basis of age‐related osteoporosis, as well as discuss relevant preclinical studies that use exogenous MSC transplantation with the aim of treating osteoporosis in murine models. We will also discuss results from specific clinical trials aimed at treating other systemic bone diseases, and how the discovery of SSC could help realize the full regenerative potential of MSC therapy to increase bone formation. Finally, we will outline how ancillary clinical trials could be initiated to assess MSC/SSC‐mediated bone formation gains in existing and potentially unrelated clinical trials, setting the stage for a dedicated clinical investigation to treat age‐related osteoporosis. Stem Cells Translational Medicine2017;6:1930–1939

Parathyroid hormone regulates fates of murine osteoblast precursors in vivo

Teriparatide, a recombinant form of parathyroid hormone (PTH), is the only approved treatment for osteoporosis that increases the rate of bone formation. Teriparatide increases osteoblast numbers by suppressing osteoblast apoptosis and activating bone-lining cells. No direct evidence for teriparatide's actions on early cells of the osteoblast lineage has been demonstrated. Here, we have employed a lineage-tracing strategy that uses a tamoxifen-dependent, promoter-driven cre to mark early cells of the osteoblast lineage in adult mice. We show that teriparatide increases the numbers of osteoblast precursors and drives their differentiation into mature osteoblasts. Unexpectedly, following withdrawal of teriparatide therapy, bone marrow adipocytes increased dramatically in number. Some of these adipocytes derived from cells marked by Sox9-cre expression weeks earlier. Continued therapy with teriparatide prevented the appearance of adipocytes. Selective, inducible deletion of the PTH receptor in Sox9-cre cells demonstrated that PTH receptor expression is required for teriparatide-mediated increases in early osteoblast precursors. The increase in early precursors after teriparatide administration was associated with robust suppression of precursor apoptosis without affecting their rate of proliferation. Thus, teriparatide increases the numbers of early cells of the osteoblast lineage, hastens their differentiation into osteoblasts, and suppresses their differentiation into adipocytes in vivo.

Systemic drugs that influence titanium implant osseointegration

Titanium implants are widely used on an increasing number of patients in orthopedic and dental medicine. Despite the good survival rates of these implants, failures that lead to important socio-economic consequences still exist. Recently, research aimed at improving implant fixation, a process called osseointegration, has focused on a new, innovative field: systemic delivery of drugs. Following implant fixation, patients receive systemic drugs that could either impair or enhance osseointegration; these drugs include anabolic and anti-catabolic bone-acting agents in addition to new treatments. Anabolic bone-acting agents include parathyroid hormone (PTH) peptides, simvastatin, prostaglandin EP4 receptor antagonist, vitamin D and strontium ranelate; anti-catabolic bone-acting agents include compounds like calcitonin, biphosphonates, RANK/RANKL/OPG system and selective estrogen receptor modulators (SERM). Examples of the new therapies include DKK1- and anti-sclerostin antibodies. All classes of treatments have proven to possess positive impacts such as an increase in bone mineral density and on osseointegration. In order to prevent complications from occurring after surgery, some post-operative systemic drugs are administered; these can show an impairment in the osseointegration process. These include nonsteroidal anti-inflammatory drugs, proton pump inhibitors and selective serotonin reuptake inhibitors. The effects of aspirin, acetaminophen, opioids, adjuvants, anticoagulants and antibiotics in implant fixations are not fully understood, but studies are being carried out to investigate potential ramifications. It is currently accepted that systemic pharmacological agents can either enhance or impair implant osseointegration; therefore, proper drug selection is essential. This review aims to discuss the varying effects of three different classes of treatments on improving this process.

Lycopene treatment against loss of bone mass, microarchitecture and strength in relation to regulatory mechanisms in a postmenopausal osteoporosis model

Lycopene supplementation decreases oxidative stress and exhibits beneficial effects on bone health, but the mechanisms through which it alters bone metabolism in vivo remain unclear. The present study aims to evaluate the effects of lycopene treatment on postmenopausal osteoporosis. Six-month-old female Wistar rats (n=264) were sham-operated (SHAM) or ovariectomized (OVX). The SHAM group received oral vehicle only and the OVX rats were randomized into five groups receiving oral daily lycopene treatment (mg/kg body weight per day): 0 OVX (control), 15 OVX, 30 OVX, and 45 OVX, and one group receiving alendronate (ALN) (2μg/kg body weight per day), for 12weeks. Bone densitometry measurements, bone turnover markers, biomechanical testing, and histomorphometric analysis were conducted. Micro computed tomography was also used to evaluate changes in microarchitecture. Lycopene treatment suppressed the OVX-induced increase in bone turnover, as indicated by changes in biomarkers of bone metabolism: serum osteocalcin (s-OC), serum N-terminal propeptide of type 1 collagen (s-PINP), serum crosslinked carboxyterminal telopeptides (s-CTX-1), and urinary deoxypyridinoline (u-DPD). Significant improvement in OVX-induced loss of bone mass, bone strength, and microarchitectural deterioration was observed in lycopene-treated OVX animals. These effects were observed mainly at sites rich in trabecular bone, with less effect in cortical bone. Lycopene treatment down-regulated osteoclast differentiation concurrent with up-regulating osteoblast together with glutathione peroxidase (GPx) catalase (CAT) and superoxide dismutase (SOD) activities. These findings demonstrate that lycopene treatment in OVX rats primarily suppressed bone turnover to restore bone strength and microarchitecture.

Surgical prevention of femoral neck fractures in elderly osteoporotic patients. A literature review

Fragility fractures of the femur are one of the major causes of morbidity and mortality worldwide. The incidence of new contralateral hip fractures in elderly osteoporotic patients ranges from 7 to 12% within 2 years after the first fracture. Secondary prevention can be divided in: pharmacological therapy based on the prescription of anti-osteoporotic drugs with different mechanism of action and non-pharmacological therapy which is based on modification of environmental risk factors, on a healthy diet with daily supplements of calcium and vitamin D and calcium and on the use of hip protectors. Recently a new form of prevention is becoming achievable: surgical prevention; the rationale of surgical reinforcement is the need to increase the resistance of the femoral neck to the compression and distraction forces acting on it. In this paper we analyse all the experimental and "on the market" device available for the surgical prevention of femoral neck fracture.

Teriparatide treatment patterns in osteoporosis and subsequent fracture events: a US claims analysis

The objective of this study was to describe the risk of fragility-related fractures in the 2 years following teriparatide initiation. In an administrative claims analysis of over 11,407 patients, approximately one in eight patients had a new or recurrent fragility-related fracture in the 2 years following teriparatide initiation.

INTRODUCTION

The objective of this study was to describe the risk of fragility-related fractures in the 2 years following the initiation of teriparatide in a real-world setting.

METHODS

This retrospective study used data from the 2002 to 2011 MarketScan® Commercial and Medicare Supplemental Databases to identify patients 50 years and older with a diagnosis of osteoporosis (ICD-9-CM code 733.0x) who were initiating teriparatide. Patients were required to have continuous medical and pharmacy benefit coverage for the 12 months prior to and 24 months following teriparatide initiation (index event). Teriparatide treatment patterns (persistence and adherence) were described, as was the use of antiresorptive therapy. The primary study outcome was the presence of a new or recurring fragility fracture following the initiation of teriparatide.

RESULTS

A total of 11,407 patients met the study criteria (mean age = 69.5, standard deviation = 10.6 years; 92.0% female). One in four (25.6%) patients had fragility fracture claims in the year prior to teriparatide initiation, of which 64.0% were on existing antiresorptive therapy. Overall, 13.4% (n = 1527) of patients had a new or recurrent fracture during the 2-year follow-up period. Forty-eight percent of patients on teriparatide treatment were considered persistent; fragility fractures were more common among patients nonpersistent with teriparatide (15.2%) than among those persistent with teriparatide (11.4%). A higher fracture rate (35.7%) was observed in the cohort with previous fragility fracture then those without pre-index fractures (24%).

CONCLUSION

More than 13.4% of patients had new or recurrent fragility-related fractures during the 2 years following the initiation of teriparatide; these fractures were more in common in patients with pre-existing fractures and the patients who were nonpersistent with teriparatide.

Literature review: The effects of teriparatide therapy at the hip in patients with osteoporosis

Teriparatide is a skeletal anabolic treatment for patients with osteoporosis at high risk for fracture. Because adequate clinical trials have not yet been conducted to assess the efficacy of teriparatide for reducing the risk of hip fracture, we review here the literature regarding how treatment with teriparatide affects the hip in patients with osteoporosis. Teriparatide increases cancellous bone volume, improves bone architecture, and - uniquely among osteoporosis treatments - increases cortical thickness and cortical porosity. By bone scan and positron emission tomography, teriparatide increases bone formation throughout the skeleton, including the hip. Consistent with these findings, studies using dual-energy X-ray absorptiometry and quantitative computed tomography for longitudinal assessment of changes at the hip have consistently shown increases in areal and volumetric bone mineral density, cortical thickness, and finite element-estimated hip strength in patients treated with teriparatide. Finally, in clinical fracture-outcome trials, treatment with teriparatide has been shown to reduce the risk of nonvertebral fracture, a composite endpoint that includes hip fracture. Taken together, this body of evidence suggests that teriparatide positively affects the hip in patients with osteoporosis.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of recombinant human parathyroid hormone (1-34) in healthy Chinese subjects

BACKGROUND

The recombinant human parathyroid hormone (1-34) (rhPTH[1-34]) teriparatide is the first anabolic agent approved by the US Food and Drug Administration for the treatment of osteoporosis in men and women. This study was conducted to provide support for marketing authorization of an agent biosimilar to teriparatide in China.

OBJECTIVE

The main aim of the present study was to assess the safety, tolerability, pharmacokinetic, and pharmacodynamic parameters of rhPTH(1-34) after single and multiple subcutaneous doses in healthy Chinese subjects.

METHODS

Two open-label, randomized, single-center, dose-escalation studies were performed. In study 1, subjects were randomized to receive a single dose of rhPTH(1-34) (10, 20, 30, 40, 50, or 60 μg) or a multiple dose of rhPTH(1-34) (10 and 20 μg once daily for 7 consecutive days) to determine the safety profile and tolerability, as reflected by the incidence, intensity, and seriousness of the observed adverse events. In study 2, a single dose of rhPTH(1-34) (10, 20, or 40 μg) and a multiple dose of rhPTH(1-34) (20 μg) were administrated subcutaneously to investigate the pharmacokinetic and pharmacodynamic parameters.

RESULTS

Forty-two subjects completed study 1, and 30 subjects completed study 2. rhPTH(1-34) was well tolerated during the investigated single (10-60 μg) and multiple (10-20 μg once daily for 7 consecutive days) dose ranges. The most generally reported adverse events were erythema at the injection site and gastrointestinal reactions. After single and multiple subcutaneous administration of rhPTH(1-34), the drug was rapidly absorbed, with a Tmax of 20 to 30 minutes, and rapidly cleared from the plasma, with a t½ of 47.2 to 60.6 minutes. The mean Cmax, AUC0-t, and AUC0-∞ increased in proportion to the doses, whereas the t½, total clearance, and Tmax values were independent of the administered dose. No significant differences in pharmacokinetic parameters were noted by sex except for Tmax in the 10-μg and 20-μg single-dose groups. Compared with the baseline levels, no significant changes or dose-related significant effects were observed in serum calcium and phosphate levels.

CONCLUSIONS

All rhPTH(1-34) doses appeared to be well tolerated in the population studied. Linear pharmacokinetic characteristics were displayed in the dose range studied. Chinese ClinicalTrials.gov identifier: ChiCTR-ONC-12002874.

A comparative study of the bone metabolic response to dried plum supplementation and PTH treatment in adult, osteopenic ovariectomized rat

Dried plum has been reported to have potent effects on bone in osteopenic animal models, but the mechanisms through which bone metabolism is altered in vivo remain unclear. To address this issue, a study comparing the metabolic response of dried plum to the anabolic agent, parathyroid hormone (PTH), was undertaken. Six month-old female Sprague Dawley rats (n=84) were sham-operated (SHAM) or ovariectomized (OVX) and maintained on a control diet for 6wks until osteopenia was confirmed. Treatments were initiated consisting of a control diet (AIN-93M) supplemented with dried plum (0, 5, 15 or 25%; w/w) or a positive control group receiving PTH. At the end of 6wks of treatment, whole body and femoral bone mineral density (BMD) were restored by the two higher doses of dried plum to the level of the SHAM group. Trabecular bone volume and cortical thickness were also improved with these two doses of dried plum. Dried plum suppressed the OVX-induced increase in bone turnover as indicated by systemic biomarkers of bone metabolism, N-terminal procollagen type 1 (P1NP) and deoxypyridinoline (DPD). Dynamic bone histomorphometric analysis of the tibial metaphysis revealed that dried plum restored the OVX-induced increase in cancellous bone formation rate (BFR) and mineralizing surface (MS/BS) to the SHAM group, but some doses of dried plum increased endocortical mineral apposition rate (MAR). As expected, PTH significantly increased endocortical MAR and BFR, periosteal BFR, and trabecular MAR and BFR beyond that of the OVX and maintained the accelerated rate of bone resorption associated with OVX. Dried plum up-regulated bone morphogenetic protein 4 (Bmp4) and insulin-like growth factor 1 (Igf1) while down-regulating nuclear factor T cell activator 1 (Nfatc1). These findings demonstrate that in the adult osteopenic OVX animal, the effects of dried plum differ from that of PTH in that dried plum primarily suppressed bone turnover with the exception of the indices of bone formation at the endocortical surface.

Screening postmenopausal women for fall and fracture prevention

Fragility fracture prevention has been historically associated with the diagnosis and treatment of osteoporosis. Given that the strongest determinant of fracture is falls, it is critical to add fall risk into clinical decision-making guidelines for fracture prevention. This special interest paper proposes an algorithm based on 2 validated tools: (1) World Health Organization's Fracture Risk Assessment Tool, which evaluates probability of fracture and (2) Functional Gait Assessment, which evaluates fall risk. Physical therapists can use this algorithm to better identify patients at greatest risk for fracture in order to customize interventions designed to promote bone health, minimize falls, and ultimately prevent fractures. Recommendations for referral, patient education, and exercise are provided for categories of varying fall and fracture risk.

Functional impairment of bone formation in the pathogenesis of osteoporosis: the bone marrow regenerative competence

The skeleton is a high-renewal organ that undergoes ongoing cycles of remodeling. The regenerative bone formation arm ultimately declines in the aging, postmenopausal skeleton, but current therapies do not adequately address this deficit. Bone marrow is the primary source of the skeletal anabolic response and the mesenchymal stem cells (MSCs), which give rise to bone matrix-producing osteoblasts. The identity of these stem cells is emerging, but it now appears that the term 'MSC' has often been misapplied to the bone marrow stromal cell (BMSC), a progeny of the MSC. Nevertheless, the changes in BMSC phenotype associated with age and estrogen depletion likely contribute to the attenuated regenerative competence of the marrow and may reflect alterations in MSC phenotype. Here we summarize current concepts in bone marrow MSC identity, and within this context, review recent observations on changes in bone marrow population dynamics associated with aging and menopause.

Nmp4/CIZ closes the parathyroid hormone anabolic window

Chronic degenerative diseases are increasing with the aging U.S. population. One consequence of this phenomenon is the need for long-term osteoporosis therapies. Parathyroid hormone (PTH), the only FDA-approved treatment that adds bone to the aged skeleton, loses its potency within two years of initial treatment but the mechanism regulating its limited "anabolic window" is unknown. We have discovered that disabling the nucleocytoplasmic shuttling transcription factor nuclear matrix protein 4/cas interacting zinc finger protein (Nmp4/CIZ) in mice extends the PTH bone-forming capacity. Nmp4 was discovered during our search for nuclear matrix transcription factors that couple this hormone's impact on osteoblast cytoskeletal and nuclear organization with its anabolic capacity. CIZ was independently discovered as a protein that associates with the focal adhesion-associated mechanosensor p130Cas. The Nmp4/CIZ-knockout (KO) skeletal phenotype exhibits a modestly enhanced bone mineral density but manifests an exaggerated response to both PTH and to BMP2 and is resistant to disuse-induced bone loss. The cellular basis of the global Nmp4/CIZ-KO skeletal phenotype remains to be elucidated but may involve an expansion of the bone marrow osteoprogenitor population along with modestly enhanced osteoblast and osteoclast activities supporting anabolic bone turnover. As a shuttling Cys(2)His(2) zinc finger protein, Nmp4/CIZ acts as a repressive transcription factor perhaps associated with epigenetic remodeling complexes, but the functional significance of its interaction with p130Cas is not known. Despite numerous remaining questions, Nmp4/CIZ provides insights into how the anabolic window is regulated, and itself may provide an adjuvant therapy target for the treatment of osteoporosis by extending PTH anabolic efficacy.

Assessing adherence to teriparatide therapy, causes of nonadherence and effect of adherence on bone mineral density measurements in osteoporotic patients at high risk for fracture

OBJECTIVES

To determine (a) adherence rates at 6, 9 and 18 months amongst patients receiving teriparatide treatment for severe osteoporosis and (b) causes of therapy discontinuation and the effect of teriparatide on bone mineral density (BMD) in adherent and nonadherent patients at different time intervals.

METHODS

A retrospective chart review of 111 patients receiving teriparatide from September 2004 to June 2007 was performed. Patients self-reports were used to record adherence and causes of nonadherence at 6, 9 and 18 months. BMDs for all patients were measured using the same DXA scanner at baseline and follow up.

RESULTS

Of 111 participants, 17 were male (mean age 60 years) and 94 were female (mean age 69 years). Of these, 12 did not initiate therapy and 4 were lost to follow up. Reported adherence was 89.6% at 6 months, 87.6% at 9 months and 74.7% at 18 months. Causes of nonadherence included cost (n = 4), no benefit (n = 1) and adverse events (n = 8). Common adverse events were leg cramps (n = 9), headache (n = 5) and myalgia (n = 4). Mean spine and femur BMD changes were 3.30% and 0.67% at 4-9 months respectively, and 5.39% and 0.77% at 10-18 months respectively.

CONCLUSION

Adherence to teriparatide was almost 90% at 9 months and decreased to 75% at 18 months. Adverse events led to nonadherence in 20% of patients. Those who were nonadherent had lower baseline BMD values than those who were adherent. Changes in BMD at the lumbar spine were greater than changes observed at the femoral neck.

Individualizing osteoporosis therapy

Guidelines for osteoporosis treatment are available; however, these guidelines suggest when to treat patients, without specific recommendations on what drugs to prescribe in various situations. Choice of osteoporosis therapy should be individualized based on consideration of the efficacy, safety, cost, convenience (i.e., dosing regimen and delivery), and other non-osteoporosis-related benefits associated with each agent. Bisphosphonates, administered orally or intravenously, should be considered first-line therapy, particularly in older patients, owing to their efficacy across multiple skeletal sites; however, there are potential short- and long-term safety concerns. Selective estrogen receptor modulators should be considered for younger postmenopausal women at greater risk for vertebral than hip fractures or as second-line therapy in women who cannot tolerate first-line therapies. Low-dose hormone therapy may be appropriate as prevention in women with menopausal symptoms at lower fracture risk. Calcitonin, with its relatively benign safety profile, may be appropriate for elderly women who may have difficulty following the complex dosing schedules of oral bisphosphonates. Anabolic therapies such as teriparatide should be considered for high-risk patients. Strontium ranelate (approved outside of North America), with both anabolic and antiresorptive properties, may be appropriate for women who cannot tolerate or are unable to take bisphosphonates. Denosumab is a monoclonal antibody appropriate for women at high fracture risk or who have failed other osteoporosis therapies, and may be considered in patients with renal insufficiency. It will be important to incorporate newer agents (e.g., bazedoxifene, tissue selective estrogen complex) into this individualized treatment paradigm to optimize clinical outcomes in patients with osteoporosis.

Treatment of repeated and multiple new-onset osteoporotic vertebral compression fractures with teriparatide

Percutaneous vertebroplasty (PVP) has played an increasing role in the treatment of osteoporotic compression fracture. The number of prior vertebral fractures and prior vertebroplasties are important risk factors for future fractures. We prospectively evaluated the effectiveness of teriparatide therapy for 28 patients who had repeated and multiple new-onset vertebral compression fractures (VCF). None of the patients required PVP or experienced a new-onset vertebral fracture during the treatment and follow-up period of at least 18 months. Teriparatide therapy significantly decreased visual analogue scale pain scores, increased Japanese Orthopaedic Association function scores, increased spinal bone mineral density, and prevented new-onset VCF. Teriparatide can be used in patients who have repeated and multiple new-onset painful VCF to avoid repeated vertebroplasty. Therapy should continue for at least six months to ensure it is effective.

Fracture risk and prevention: a multidimensional approach

Although physical therapists commonly manage neuromusculoskeletal disorders and injuries, their scope of practice also includes prevention and wellness. In particular, this perspective article proposes that physical therapists are well positioned to address the client's skeletal health by incorporating fracture prevention into clinical practice with all adults. Fracture prevention consists primarily of maximizing bone strength and preventing falls. Both of these initiatives require an evidence-based, multidimensional approach that customizes interventions based on an individual's medical history, risk factors, and personal goals. The purposes of this perspective article are: (1) to review the role of exercise and nutrition in bone health and disease; (2) to introduce the use of the Fracture Risk Assessment Tool (FRAX®) into physical therapist practice; (3) to review the causes and prevention of falls; and (4) to propose a role for the physical therapist in promotion of bone health for all adult clients, ideally to help prevent fractures and their potentially devastating sequelae.

Calcilytics: antagonists of the calcium-sensing receptor for the treatment of osteoporosis

The only bone anabolic agents currently available on the market are based on the parathyroid hormone (PTH). Secretion of endogenous PTH is controlled by a calcium-sensing receptor at the surface of the parathyroid glands. Antagonists of this receptor (calcilytics) induce the release of the hormone. Provided the effect of the calcilytic is of short duration, a bone anabolic effect should also result. Although the first calcilytic series became known approximately 10 years ago, the number of different structural types is still small today. This article outlines the quest from hits to potent development candidates of all relevant calcilytic series currently known. Even after the front-runners unexpectedly failed in the clinic, the approach for an oral alternative to parenteral PTH remains highly attractive.

Nmp4/CIZ suppresses the response of bone to anabolic parathyroid hormone by regulating both osteoblasts and osteoclasts

How parathyroid hormone (PTH) increases bone mass is unclear, but understanding this phenomenon is significant to the improvement of osteoporosis therapy. Nmp4/CIZ is a nucleocytoplasmic shuttling transcriptional repressor that suppresses PTH-induced osteoblast gene expression and hormone-stimulated gains in murine femoral trabecular bone. To further characterize Nmp4/CIZ suppression of hormone-mediated bone growth, we treated 10-week-old Nmp4-knockout (KO) and wild-type (WT) mice with intermittent human PTH(1-34) at 30 μg/kg daily or vehicle, 7 days/week, for 2, 3, or 7 weeks. Null mice treated with hormone (7 weeks) gained more vertebral and tibial cancellous bone than WT animals, paralleling the exaggerated response in the femur. Interestingly, Nmp4/CIZ suppression of this hormone-stimulated bone formation was not apparent during the first 2 weeks of treatment. Consistent with the null mice enhanced PTH-stimulated addition of trabecular bone, these animals exhibited an augmented hormone-induced increase in serum osteocalcin 3 weeks into treatment. Unexpectedly, the Nmp4-KO mice displayed an osteoclast phenotype. Serum C-terminal telopeptide, a marker for bone resorption, was elevated in the null mice, irrespective of treatment. Nmp4-KO bone marrow cultures produced more osteoclasts, which exhibited elevated resorbing activity, compared to WT cultures. The expression of several genes critical to the development of both osteoblasts and osteoclasts was elevated in Nmp4-KO mice at 2 weeks, but not 3 weeks, of hormone exposure. We propose that Nmp4/CIZ dampens PTH-induced improvement of trabecular bone throughout the skeleton by transiently suppressing hormone-stimulated increases in the expression of proteins key to the required enhanced activity and number of both osteoblasts and osteoclasts.

The role and efficacy of denosumab in the treatment of osteoporosis: an update

INTRODUCTION

Bone strength determinants such as bone mineral density and bone quality parameters are determined by life-long remodeling of skeletal tissue. Denosumab is a fully human mAb receptor activator of NF-κB ligand, which selectively inhibits osteoclastogenesis, the end product of a cascade interaction among numerous systemic and local factors and osteoblasts. It has been approved for clinical use by the FDA in the US and by the European Medicines Agency in Europe since June 2010 (trade name Prolia(™), Amgen, Thousand Oaks, CA, USA).

AREAS COVERED

This review establishes the concerns and provides insights in issues concerning the cost-effectiveness and safety profile of this new pharmaceutical agent. There is an effort to clarify the special characteristics and the anti-catabolic role of denosumab in the bone tissue homeostasis and more specifically its potential clinical applications and clinical results in the field of postmenopausal osteoporosis.

EXPERT OPINION

Administrated as a subcutaneous injection every 6 months, denosumab has been shown to decrease bone turnover and increase bone mineral density in postmenopausal women with low bone mass or osteoporosis and reduce vertebral, hip and nonvertebral fracture risk in postmenopausal women with osteoporosis. The rapid, sustained and reversible effect in suppressing osteoclastic bone resorption, the return of responsiveness on rechallenge, its good tolerability and ease of administration are features that distinguish it from other antiresorptive therapies.

Incidence of new fractures in women with osteoporosis-induced vertebral fractures detected on routine lateral chest radiographs

PURPOSE

Vertebral fractures represent one of the major complications of osteopororis. Diagnosis is followed by a pharmacological, interventional or surgical treatment. Up to day there are non practice guidelines for a screening evaluation of bone fractures in elderly and most of the fractures remain undiagnosed. We prospectively evaluated the prevalence of vertebral fractures on chest X-rays to determine the diagnostic and prognostic roles of chest X-ray in predicting new bone fractures 2 years after the initial radiogram.

MATERIALS AND METHODS

Between March 2004 and October 2005, 4,045 women underwent chest X-ray in our radiology department for any indication. We identified 166 women with the presence of at least one vertebral fracture. A questionnaire was administered to these women to collect information about diagnosis of osteoporosis, history of malignancy, systemic diseases, osteoporosis-inducing drugs and pharmacological, radiological or surgical treatment received.

RESULTS

Out of the 166 women (age 73+/-10.5 years) with vertebral fractures, we interviewed 101 women; 13 had died and 52 were not found. Most of the patients were on menopause (97.1%, 98/101) with an average age of menopause of 48,2 years (+/-6 years). Among the patients on menopause, 15,8% (16/101) had undergone hysterectomy. All patients received a diagnosis of osteoporosis, which was reached with a chest X-ray report in 23.7% (24/101) of cases. A new skeletal fracture occurred in 20.5% (5/27) of patients receiving treatment against a frequency of 20.8% (16/74) in patients without treatment. No statistical difference was found between the groups (p = 0.374).

CONCLUSIONS

Inadequate treatment may explain the lack of a substantial difference in new fracture risk between treated and untreated patients. For these reason we discuss about the evaluation of an adeguate therapeutic approaches in prevention of osteoporosis-induced fractures.

Effect of teriparatide [rhPTH(1,34)] and calcitonin on intertransverse process fusion in a rabbit model

STUDY DESIGN

Randomized, double-blinded, placebo controlled animal study.

OBJECTIVE

To evaluate the effect of teriparatide and calcitonin after an intertransverse process spinal fusion in a rabbit model.

SUMMARY OF BACKGROUND DATA

It is widely recognized that some osteoporosis medications, including bisphosphonates, can interfere with bone healing. Although prescribed frequently in the treatment of osteoporosis, the effect of teriparatide and calcitonin on spinal fusion has not been fully elucidated. We hypothesized that teriparatide, being the only anabolic medication for osteoporosis treatment, would have a beneficial effect on spine fusion.

METHODS

Fifty-one New Zealand white rabbits underwent a posterolateral L5-L6 intertransverse process arthrodesis using autogenous iliac crest bone graft. The rabbits were randomly divided into 3 groups. All animals received daily subcutaneous injections of group I (n = 17) 1 mL of saline placebo; group II (n = 17) 10 microg/kg/day of teriparatide; group III (n = 17) 14 IU/animal of calcitonin during the 8-week postoperative period. Postmortem analyses included manual palpation, radiographic, biomechanical, and histologic assessment. Three random 10x fields were examined/graded within the cephalad, middle, and caudal regions of each section (810 fields). Fusion quality was graded using the Emery histologic scale (0-7 based on fibrous/bone content of the fusion mass).

RESULTS

Histologic fusion rates for teriparatide averaged 86.7% and was significantly greater than the autograft control group (50%) (P = 0.033). Radiographically, there was a strong trend towards teriparatide being superior to the calcitonin group (85.7% vs. 56.3%, respectively; P = 0.07). The average Emery grading score was 5.99 +/- 1.46 SD for the autologous group and 6.26 +/- 0.93 SD for the teriparatide group (P = 0.031). Although not significant, the teriparatide group showed less motion in flexion/extension, lateral bending, and axial rotation.

CONCLUSION

Our results suggest that teriparatide enhances spinal fusion while calcitonin has a neutral effect. The teriparatide group had the best histologic fusion rate and Emery scores, while the calcitonin group was similar to the saline controls. Although not significant, the teriparatide group had a strong trend towards superior radiographic fusion over the calcitonin group.

Teriparatide: a review of its use in osteoporosis

Recombinant teriparatide (Forteo; Forsteo) is an anabolic (bone forming) agent. Studies have shown that subcutaneous teriparatide 20 microg/day is effective in women with postmenopausal osteoporosis, men with idiopathic or hypogonadal osteoporosis and patients with glucocorticoid-induced osteoporosis. Teriparatide improves bone mineral density (BMD) and alters the levels of bone formation and resorption markers; histomorphometric studies showed teriparatide-induced effects on bone structure, strength and quality. Subcutaneous teriparatide 20 microg/day administered over a treatment period of 11-21 months was effective in reducing the risk of fractures in and in improving BMD in men with idiopathic or hypogonadal osteoporosis, women with postmenopausal osteoporosis and patients with glucocorticoid-induced osteoporosis. Furthermore, the beneficial effects of teriparatide on vertebral fracture prevention and BMD appear to persist following treatment cessation. Teriparatide is generally well tolerated and treatment compliance rates are favourable. However, current limitations on the length of treatment and the high acquisition cost mean that teriparatide is best reserved for the treatment of patients with osteoporosis at high risk of fracture, or for patients with osteoporosis who have unsatisfactory responses to or intolerance of other osteoporosis therapies.

Treatment of osteoporosis with parathyroid hormone and teriparatide

Nowadays osteoporosis treatment is based primarily on therapy with antiresorptive agents, like the bisphosphonates. Parathyroid hormone (Preotact) and human recombinant parathyroid hormone peptide 1-34 (Teriparatide) are relatively new for the treatment of osteoporosis and belong to the group of anabolic agents. Both agents demonstrated an increase in bone mineral density and a significant reduction in vertebral fractures in postmenopausal women with osteoporosis when given for 18-24 months. Data on nonvertebral fractures are, however, not clear-cut, and so far only bisphosphonates and strontium ranelate have been demonstrated to reduce all types of fractures and therefore remain the front-line option for treatment of osteoporosis. As the safety, tolerability, and cost of the therapy also influence the choice of therapy, Preotact and Teriparatide might be useful additions to the armamentarium for (second-line) treatment of osteoporosis.

Osteoporosis in men: its pathophysiology and the role of teriparatide in its treatment

As the population ages, the burden of osteoporosis in men is expected to rise. Implementation of preventive measures such as falls prevention strategies, exercise and adequate calcium and vitamin D intake is recommended. However, when the diagnosis of osteoporosis is made, effective treatments need to be initiated to prevent fractures. As opposed to postmenopausal women, reduced bone formation is the predominant mechanism of age-related bone loss in men, making anabolic agents a logical treatment option for men with osteoporosis. Teriparatide is the only anabolic agent currently approved for treatment of osteoporosis in men. This paper summarizes the mechanism of action of teriparatide, as well as its tolerability and safety. Furthermore, the evidence supporting the efficacy of teriparatide treatment in men with osteoporosis is reviewed and its current role in the management of osteoporosis in men is discussed.