Teriparatide: a review of its use in osteoporosis

At least one cyclic teriparatide administration can be helpful to delay initial onset of a new osteoporotic vertebral compression fracture

PURPOSE

Teriparatide markedly increases bone formation and strength, while reducing the incidence of new-onset osteoporotic vertebral compression fractures (OVCFs). In some countries, expenses for teriparatide use are covered by medical insurance for up to 6 months; however, the national medical insurance of the authors' country does not cover these expenses. This retrospective cohort study compared the therapeutic effects of teriparatide on the initial onset of a new OVCF after treatment of osteoporosis and/or related OVCFs with regard to therapeutic durations of longer than 3 months (LT3M) or shorter than 3 months (ST3M).

MATERIALS AND METHODS

From May 2007 to February 2012, 404 patients who were prescribed and administered teriparatide and who could be followed-up for longer than 12 months were enrolled. They were divided into two groups depending on teriparatide duration: LT3M (n=132) and ST3M (n=272).

RESULTS

The group with the teriparatide duration of LT3M showed significantly less development of an initial OVCF within 1 year (p=0.004, chi-square). Duration of teriparatide use, body mass index, pre-teriparatide lowest spinal bone mineral density, and severity of osteoporosis significantly affected multiple regression analysis results (p<0.05). Survival analysis of first new-onset OVCFs demonstrated a significantly better survival rate for the LT3M group (log rank, p=0.005). Also, the ST3M group showed a higher odds ratio of 54.00 for development of an initial OVCF during follow-up than the LT3M group (Mantel-Haenzel common odds ratio, p=0.006).

CONCLUSION

At least one cyclic teriparatide administration is recommended to provide a protective effect against the initial onset of a new OVCF for up to one year after therapy.

Structure-based drug design for G protein-coupled receptors

Our understanding of the structural biology of G protein-coupled receptors has undergone a transformation over the past 5 years. New protein-ligand complexes are described almost monthly in high profile journals. Appreciation of how small molecules and natural ligands bind to their receptors has the potential to impact enormously how medicinal chemists approach this major class of receptor targets. An outline of the key topics in this field and some recent examples of structure- and fragment-based drug design are described. A table is presented with example views of each G protein-coupled receptor for which there is a published X-ray structure, including interactions with small molecule antagonists, partial and full agonists. The possible implications of these new data for drug design are discussed.

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.

New therapeutical horizons in the management of postmenopausal osteoporosis

Osteoporosis is a bone metabolic disease characterized by a compromised skeletal fragility, leading to an increased risk of developing spontaneous and traumatic fractures. This disease is the consequence of an imbalance of the physiological process of bone turnover (or coupling), with the lost of the equilibrium between the activity of osteoblasts and osteoclasts. Therapy has been aimed mainly at the correction of the imbalance between bone resorption and bone formation, to protect skeletal integrity and reduce the risk of fractures. Thus, pharmacological treatments have been aimed at modulating the activity of bone cells.

Adverse drug reactions to osteoporosis treatments

Treatments for postmenopausal osteoporosis are generally safe, but are linked to some rare serious adverse drug reactions, for which causality is not always certain. The bisphosphonates are associated with gastrointestinal effects, acute phase reactions, and musculoskeletal pain, and, more rarely, cases of atrial fibrillation, subtrochanteric fracture, osteonecrosis of the jaw, cutaneous hypersensitivity reactions and renal impairment. It is too soon for pharmacovigilance data on denosumab, but it has been associated with cutaneous effects and possibly osteonecrosis of the jaw (to date, only in metastatic cancer). The selective estrogen receptor modulators may induce hot flushes and leg cramps, and--more rarely--venous thromboembolism and stroke. Strontium ranelate is associated with headache, nausea and diarrhea, and, more rarely, cutaneous hypersensitivity reactions and venous thromboembolism, while teriparatide and parathyroid hormone(1-84) are associated with headache, nausea, dizziness and limb pain. The management of osteoporosis should entail weighing the probability of adverse reactions against the benefits of therapy--that is, reduction of fracture risk.

Bone loss and avascular necrosis of bone after hematopoietic cell transplantation

Advances in transplantation technology and supportive care measures have resulted in significant decrease in early mortality resulting in continued growth in the number of long-term hematopoietic cell transplantation (HCT) survivors. The intensity of chemotherapy and total body irradiation regimen used pretransplantation to eradicate the primary disease can lead to organ toxicities, including significant bone complications after HCT. Bone loss is frequent in HCT recipients and results from impaired bone mineralization through disturbances of calcium and vitamin D homeostasis, osteoblast and osteoclast dysfunction, and deficiencies in growth or gonadal hormone secretion. Exposure to glucocorticoids and calcineurin inhibitors for prevention and treatment of graft-versus-host disease (GVHD) represents one of the major causes for the increased risk of osteoporosis and avascular necrosis of bone (AVN) in recipients of allogeneic HCT. In this article we review the incidence, pathogenesis, and risk factors for osteoporosis and AVN after allogeneic HCT and discuss general guidelines for their treatment and monitoring based on the limited available reports.

Prospective comparison of the therapeutic effect of teriparatide with that of combined vertebroplasty with antiresorptive agents for the treatment of new-onset adjacent vertebral compression fracture after percutaneous vertebroplasty

Most post-vertebroplasty new-onset adjacent vertebral compression fractures (VCFs) occur within 2-3 months, and antiresorptive agents do not significantly reduce the risk of their occurrence. In opposite mechanism, teriparatide directly stimulates bone formation and improves bone strength and quality faster. The therapeutic effect of teriparatide is better than that of vertebroplasty combined with an antiresorptive treatment and is a potentially useful therapy for new-onset adjacent VCFs after vertebroplasty.

INTRODUCTION

Following vertebroplasty, patients are at increased risk of new-onset adjacent-level VCFs. The therapeutic effect of antiresorptive agents is too slow, and they are associated with the risk of new VCFs. Teriparatide markedly increases bone formation and strength and reduces the incidence of new-onset VCFs. This prospective cohort study compared the therapeutic effects of teriparatide with those of combined vertebroplasty and an anti-resorber for treating new-onset adjacent VCFs after vertebroplasty.

METHODS

Fifty patients with adjacent VCFs were randomly assigned to two groups: teriparatide only (group A) and additional vertebroplasty combined with an antiresorptive agent (group B). Relevant clinical data of the two groups were prospectively compared.

RESULTS

The 22 patients in group A were at higher risk of new VCFs than those in group B (22 patients); they were older and had more pre-existing fractures (p < 0.05). Patients treated with teriparatide had a significantly lower incidence of new-onset VCFs (odds ratio = 0.21; 95% confidence interval, 0.02-2.10). Teriparatide-mediated VCF reduction was 78.57%, which was markedly better than that of group B. The teriparatide group had a significant decrease in the visual analog scale and an increase in the Japanese Orthopedic Association low back pain score after 6 months of treatment (p < 0.05). The increase in lumbar spine BMD was marked in the teriparatide group (21.70% vs. 6.87%) after an 18-month treatment.

CONCLUSIONS

Treatment of post-vertebroplasty adjacent VCFs with teriparatide (no new vertebroplasty) was more effective than that of repeated vertebroplasties combined with an anti-resorber.

Teriparatide - Indications beyond osteoporosis

Osteoporosis is a condition of impaired bone strength that results in an increased risk of fracture. The current and most popular pharmacological options for the treatment of osteoporosis include antiresorptive therapy, in particular, oral bisphosphonates (alendronate, risedronate, ibandronate). Anabolic agents like teriparatide have widened our therapeutic options. They act by directly stimulating bone formation and improving bone mass quantity and quality. Two forms of recombinant human parathyroid hormone (PTH) are available : full-length PTH (PTH 1-84; approved in the EU only) and the 1-34 N-terminal active fragment of PTH (teriparatide, US FDA approved). This review aims to discuss the benefits of teriparatide beyond the currently licensed indications like fracture healing, dental stability, osteonecrosis of jaw, hypoparathyroidism, and hypocalcemia.

Validation of the adherence evaluation of osteoporosis treatment (ADEOS) questionnaire for osteoporotic post-menopausal women

SUMMARY

We developed and validated a specific 12-item questionnaire to evaluate adherence to oral antiresorptive medication by post-menopausal osteoporotic women in everyday practice. Over the following 9 months, an index of ≤16 was associated with an increase in the risk of treatment discontinuation of 1.69 and of 2.10 for new patients who had started treatment within the previous year.

INTRODUCTION

Adherence to medication in osteoporosis is poor. The goal of this study was to develop and validate a disease-specific questionnaire to evaluate adherence to treatment of women with post-menopausal osteoporosis taking oral antiresorptive medication.

METHODS

A prototype adherence questionnaire with 45 items developed from patient interview, literature review, and physician opinion was evaluated in a sample of 350 post-menopausal women with osteoporosis treated in primary care. Item responses were matched against scores on the Morisky Medication Adherence Scale (MMAS). The most discriminant items were retained in the final questionnaire. Concurrent and predictive validity were assessed.

RESULTS

Twelve items were associated with MMAS score at a probability level of 0.05. These were retained in the final questionnaire which provided an adherence index ranging from 0 to 22. An index of ≥20 was associated with a high probability of persistence and an index ≤ 16 with a high probability of treatment discontinuation in the following 9 months.

CONCLUSIONS

The ADEOS-12 is a simple patient-reported measure to determine adherence to osteoporosis treatments with good concurrent and discriminant validity. This is the first disease-specific adherence measure to have been developed for osteoporosis.

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.

Adverse reactions and drug-drug interactions in the management of women with postmenopausal osteoporosis

The pharmacological management of disease should involve consideration of the balance between the beneficial effects of treatment on outcome and the probability of adverse effects. The aim of this review is to explore the risk of adverse drug reactions and drug-drug interactions with treatments for postmenopausal osteoporosis. We reviewed evidence for adverse reactions from regulatory documents, randomized controlled trials, pharmacovigilance surveys, and case series. Bisphosphonates are associated with gastrointestinal effects, musculoskeletal pain, and acute-phase reactions, as well as, very rarely, atrial fibrillation, atypical fracture, delayed fracture healing, osteonecrosis of the jaw, hypersensitivity reactions, and renal impairment. Cutaneous effects and osteonecrosis of the jaw are of concern for denosumab (both very rare), though there are no pharmacovigilance data for this agent yet. The selective estrogen receptor modulators are associated with hot flushes, leg cramps, and, very rarely, venous thromboembolism and stroke. Strontium ranelate has been linked to hypersensitivity reactions and venous thromboembolism (both very rare) and teriparatide with headache, nausea, dizziness, and limb pain. The solidity of the evidence base depends on the frequency of the reaction, and causality is not always easy to establish for the very rare adverse reactions. Drug-drug interactions are rare. Osteoporosis treatments are generally safe and well tolerated, though they are associated with a few very rare serious adverse reactions. While these are a cause for concern, the risk should be weighed against the benefits of treatment itself, i.e., the prevention of osteoporotic fracture.

Teriparatide: Its Use in the Treatment of Osteoporosis

The prevalence of osteoporosis is likely to rise with the increase in life expectancy of an ageing population. Current first line therapies for the treatment of osteoporosis are predominantly anti-resorptive. Teriparatide is a first in class, anabolic agent with a unique mechanism that results in increased bone formation. Daily subcutaneous injection for 6–24 months was effective in reducing vertebral and non-vertebral fracture rates, in improving bone mineral density (BMD) and in increasing bone formation rates in postmenopausal osteoporosis, with effects persisting following treatment cessation. Similar benefits on bone mass and bone formation were seen in men with osteoporosis and glucocorticoid induced osteoporosis. Beneficial effects on bone mass have been demonstrated in treatment naive subjects treated with teriparatide alone, sequentially with anti-resorptive therapy and concomitantly with some, but not all, anti-resorptive treatments due to an early blunting of the anabolic effect. Teriparatide is generally well tolerated. However, the high treatment cost and inconvenient mode of administration has limited it's use to patients with osteoporosis who have experienced an unsatisfactory response, who are intolerant to other osteoporosis therapies, or to patients at very high risk of fracture. Teriparatide treatment is currently restricted to a total lifetime treatment dose of 18 months of daily subcutaneous therapy due to concerns from animal studies suggesting an increased risk of osteosarcoma. More safety data may permit a longer duration of treatment in the future but will necessitate prolonged human studies. Teriparatide may serve a more prominent role in the treatment of older patients who continue to fracture despite low bone turnover or sustain side effects with anti-resorptive therapy.

Effects of 1 year of daily teriparatide treatment on iliacal bone mineralization density distribution (BMDD) in postmenopausal osteoporotic women previously treated with alendronate or risedronate

Anabolic treatment with teriparatide of postmenopausal osteoporotic patients previously treated with bisphosphonates is a new therapeutic approach. However, its effects on the bone mineralization density distribution (BMDD) are unknown. We studied paired transiliac bone biopsy samples taken before and after 1 year of treatment with recombinant human parathyroid hormone peptide 1-34 (teriparatide) from 16 osteoporotic women treated with either alendronate (priorALN) or risedronate (priorRIS) for at least 2 years and subsequently treated for 12 months with teriparatide. Cancellous (Cn.) and cortical (Ct.) BMDD values were measured using quantitative backscattered electron imaging. At baseline, BMDD values of priorALN and priorRIS women were similar and within the normal range. One year of teriparatide treatment caused significant effects on the BMDD. Analyzing changes from baseline for each bisphosphonate group separately, priorALN patients revealed increases in the portion of low mineralized bone areas (Cn.Ca(Low) +25.9%, Ct.Ca(Low) +62.0%, both p < .05) and Ct. heterogeneity of mineralization (Ct.Ca(Width) +22.8%, p < .001). PriorRIS patients showed increased mineralization heterogeneity (Cn.Ca(Width) +14.8%, p < .05, and Ct.Ca(Width) +15.8%, p < .001). Analysis of the influence of the prior bisphosphonate treatment showed that the BMDD response to 1 year of teriparatide treatment did not depend on the type of prior bisphosphonate. In consequence, priorALN and priorRIS groups were combined. The pooled groups revealed increased Cn.Ca(Width) and Ct.Ca(Width) (+10.7%, p < .01, and +19.6%, p < .001, respectively) as well as increased Cn.Ca(Low) and Ct.Ca(Low) (+18.2%, p < .05, and +36.6%, p < .01, respectively). In summary, our findings indicate a significant effect of teriparatide on BMDD when administered subsequent to a bisphosphonate in agreement with teriparatide's anabolic action.

Profile of teriparatide in the management of postmenopausal osteoporosis

One out of every 2 women within postmenopause are at risk of fracture due to osteoporosis. Fortunately, a growing arsenal of therapies is becoming available to treat this disease and prevent fracture. A new class of anabolic agents has emerged within the last decade that brought with it a new concept in osteoporosis therapy: building new stronger bone rather than simply inhibiting bone turnover. Evidence is accumulating to understand how to best utilize these new agents, and which patients benefit most. This article will review the effectiveness, risks, timing and clinical uses of teriparatide in postmenopausal osteoporosis.

Management of osteoporosis in CKD Stages 3 to 5

Osteoporosis and chronic kidney disease (CKD) are both common conditions of older adults and both may be associated with substantial morbidity. However, biochemical and histologic changes that occur with progressive kidney disease require specific interventions, some of which may be concordant with osteoporosis management in the general population, whereas others may be less relevant or perhaps even harmful. In this article, we review the diagnosis of and management strategies for osteoporosis in individuals with CKD, placing these into perspective with the recently published KDIGO (Kidney Disease: Improving Global Outcomes) guidelines for treatment of CKD-mineral and bone disorder (CKD-MBD). Specifically, we highlight osteoporosis treatment recommendations by CKD stage and discuss new avenues for osteoporosis treatment that may be useful in individuals with CKD.

RAGE supports parathyroid hormone-induced gains in femoral trabecular bone

Parathyroid hormone (PTH) restores bone mass to the osteopenic skeleton, but significant questions remain as to the underlying mechanisms. The receptor for advanced glycation end products (RAGE) is a multiligand receptor of the immunoglobulin superfamily; however, recent studies indicate a role in bone physiology. We investigated the significance of RAGE to hormone-induced increases in bone by treating 10-wk-old female Rage-knockout (KO) and wild-type (WT) mice with human PTH-(1-34) at 30 microg.kg(-1).day(-1) or vehicle control, 7 days/wk, for 7 wk. PTH produced equivalent relative gains in bone mineral density (BMD) and bone mineral content (BMC) throughout the skeleton in both genotypes. PTH-mediated relative increases in cortical area of the midshaft femur were not compromised in the null mice. However, the hormone-induced gain in femoral cancellous bone was significantly attenuated in Rage-KO mice. The loss of RAGE impaired PTH-mediated increases in femoral cancellous bone volume, connectivity density, and trabecular number but did not impact increases in trabecular thickness or decreases in trabecular spacing. Disabling RAGE reduced femoral expression of bone formation genes, but their relative PTH-responsiveness was not impaired. Neutralizing RAGE did not attenuate vertebral cancellous bone response to hormone. Rage-null mice exhibited an attenuated accrual rate of bone mass, with the exception of the spine, and an enhanced accrual rate of fat mass. We conclude that RAGE is necessary for key aspects of the skeleton's response to anabolic PTH. Specifically, RAGE is required for hormone-mediated improvement of femoral trabecular architecture but not intrinsically necessary for increasing cortical thickness.

Nmp4/CIZ: road block at the intersection of PTH and load

Teriparatide (parathyroid hormone, [PTH]) is the only FDA-approved drug that replaces bone lost to osteoporosis. Enhancing PTH efficacy will improve cost-effectiveness and ameliorate contraindications. Combining this hormone with load-bearing exercise may enhance therapeutic potential consistent with a growing body of evidence that these agonists are synergistic and share common signaling pathways. Additionally, neutralizing molecules that naturally suppress the anabolic response to PTH may also improve the efficacy of treatment with this hormone. Nmp4/CIZ (nuclear matrix protein 4/cas interacting zinc finger)-null mice have enhanced responses to intermittent PTH with respect to increasing trabecular bone mass and are also immune to disuse-induced bone loss likely by the removal of Nmp4/CIZ suppressive action on osteoblast function. Nmp4/CIZ activity may be sensitive to changes in the mechanical environment of the bone cell brought about by hormone- or mechanical load-induced changes in cell shape and adhesion. Nmp4 was identified in a screen for PTH-responsive nuclear matrix architectural transcription factors (ATFs) that we proposed translate hormone-induced changes in cell shape and adhesion into changes in target gene DNA conformation. CIZ was independently identified as a nucleocytoplasmic shuttling transcription factor associating with the mechano-sensitive focal adhesion proteins p130Cas and zxyin. The p130Cas/zyxin/Nmp4/CIZ pathway resembles the beta-catenin/TCF/LEF1 mechanotransduction response limb and both share features with the HMGB1 (high mobility group box 1)/RAGE (receptor for advanced glycation end products) signaling axis. Here we describe Nmp4/CIZ within the context of the PTH-induced anabolic response and consider the place of this molecule in the hierarchy of the PTH-load response network.

PDE4 inhibitor upregulates PTH-induced osteoclast formation via CRE-mediated COX-2 expression in osteoblasts

We investigated the interplay between parathyroid hormone (PTH) and phosphodiesterases (PDEs) in osteoblasts. PDE4 negatively regulated PTH-induced cAMP accumulation. PDE4 inhibitor enhanced PTH-induced osteoclast formation and RANKL mRNA expression, which is partially mediated by COX-2 mRNA expression. Two CRE sites in the COX-2 promoter were required for the increase in COX-2 transcription by PDE4 inhibitor, and the expression of a dominant-negative form of CREB abolished COX-2 mRNA expression in response to PDE4 inhibitor or PTH in osteoblasts. Taken together, our data indicate that PDE4 inhibitor promotes PTH-induced osteoclast formation partially via CRE-mediated COX-2 mRNA expression.

Management of glucocorticoids-induced osteoporosis: role of teriparatide

Glucocorticoids (GC)-induced osteoporosis (GIOP) is the most common cause of secondary osteoporosis, which leads to an increased fracture risk in patients. The normal bone turnover depends on a balance between osteoblasts and osteoclasts activity and GC can cause a rapid bone loss, decreasing bone formation and increasing bone resorption. The decreased bone formation is mainly due to the GC-induced apoptosis of both osteoblasts and osteocytes, while the increased bone resorption is due to the increased life-span of pre-existing osteoclasts. Bisphosphonates are clearly effective in preventing and treating GIOP but anabolic therapeutic strategies are the new promising therapeutic alternative. Experimental and clinical studies indicate that teriparatide, the active (1–34) parathyroid hormone (PTH) molecule, is efficacious for the treatment of GIOP, being able to induce an increase in bone mass in these patients. Intermittent administration of human PTH (1–34) stimulates bone formation by increasing osteoblast number. Additionally, human PTH (1–34) modulates the level and/or activity of locally produced growth factors and cytokines. Teriparatide has been demonstrated in several clinical studies to significantly decrease the incidence of fractures in patients affected by GIOP. It has recently received an indication for GIOP and its label indication has also been expanded.