Clinical update on teriparatide

Treatment period and changes in bone markers according to the application of teriparatide in treating medication-related osteonecrosis of the jaw

BACKGROUND

This study aimed to explore the effects of teriparatide (TPTD) on treatment duration, surgical procedures, and bone turnover markers in medication-related osteonecrosis of the jaw (MRONJ).

METHODS

We analyzed 76 patients with MRONJ post-treatment and divided them into conservative/surgical and TPTD/non-TPTD groups. Key assessments included treatment duration, surgery count, and changes in bone markers (serum C-terminal telopeptide of type 1 collagen [CTX], osteocalcin [OC], procollagen type 1 N-terminal propeptide [P1NP], parathyroid hormone [PTH], 25-OH-vitamin D [25(OH)D], calcium, and inorganic phosphorus) measured at the initial and post-treatment stages.

RESULTS

TPTD-treated surgical patients experienced shorter treatment periods and underwent fewer surgeries than did non-TPTD counterparts. Post-treatment, both groups showed significant increases in CTX, OC, and 25(OH)D levels. P1NP elevation was significant only in the non-TPTD group. Although the PTH levels decreased in both groups, the difference was not statistically significant. Calcium and phosphorus levels increased in both groups, but only calcium levels increased significantly in the TPTD group. Additionally, TPTD-treated patients showed significant improvements in T-scores, particularly in the lumbar spine and femur neck, compared to the non-TPTD group.

CONCLUSIONS

TPTD administration during MRONJ treatment potentially reduces the need for surgical intervention and accelerates recovery, significantly affecting bone metabolism. These findings highlight TPTD's role in enhancing the efficacy of MRONJ treatment. TPTD could potentially offer the dual benefit of promoting bone healing and reducing the need for surgical intervention, thus improving overall outcomes for patients with MRONJ.

Pharmacological options in the treatment of osteogenesis imperfecta: A comprehensive review of clinical and potential alternatives

Osteogenesis imperfecta (OI) is a genetically heterogeneous connective tissue disorder characterized by bone fragility and different extra-skeletal manifestations. The severity of these manifestations makes it possible to classify OI into different subtypes based on the main clinical features. This review aims to outline and describe the current pharmacological alternatives for treating OI, grounded on clinical and preclinical reports, such as antiresorptive agents, anabolic agents, growth hormone, and anti-TGFβ antibody, among other less used agents. The different options and their pharmacokinetic and pharmacodynamic properties will be reviewed and discussed, focusing on the variability of their response and the molecular mechanisms involved to attain the main clinical goals, which include decreasing fracture incidence, improving pain, and promoting growth, mobility, and functional independence.

WNT7B overexpression rescues bone loss caused by glucocorticoids in mice

Glucocorticoids, widely prescribed for anti-inflammatory and immunosuppressive purposes, are the most common secondary cause for osteoporosis and related fractures. Current anti-resorptive and anabolic therapies are insufficient for treating glucocorticoid-induced osteoporosis due to contraindications or concerns of side effects. Glucocorticoids have been shown to disrupt Wnt signaling in osteoblast-lineage cells, but the efficacy for Wnt proteins to restore bone mass after glucocorticoid therapy has not been examined. Here by using two mouse genetic models wherein WNT7B expression is temporally activated by either tamoxifen or doxycycline in osteoblast-lineage cells, we show that WNT7B recovers bone mass following glucocorticoid-induced bone loss, thanks to increased osteoblast number and function. However, WNT7B overexpression in bone either before or after glucocorticoid treatments does not ameliorate the abnormal accumulation of body fat. The study demonstrates a potent bone anabolic function for WNT7B in countering glucocorticoid-induced bone loss.

The Indian Society for Bone and Mineral Research (ISBMR) position statement for the diagnosis and treatment of osteoporosis in adults

The Indian Society for Bone and Mineral Research (ISBMR) has herein drafted clinical practice guidelines for the diagnosis and management of osteoporosis for the people of India. Implementation of the position statement in clinical practice is expected to improve the overall care of patients with osteoporosis in India.

PURPOSE

In India, osteoporosis is a major public health problem. However, in the absence of any robust regional guidelines, the screening, treatment, and follow-up of patients with osteoporosis are lagging behind in the country.

METHODS

The Indian Society for Bone and Mineral Research (ISBMR), which is a multidisciplinary group of physicians, researchers, dietitians, and epidemiologists and who study bone and related tissues, in their annual meeting, drafted the guidelines for the diagnosis and management of osteoporosis that would be appropriate in a resource constraint setting like India.

RESULTS

Diagnosis of osteoporosis can be made in a patient with minimal trauma fracture without the aid of any other diagnostic tools. In others, bone mineral density measured by dual-energy X-ray absorptiometry remains the modality of choice. Data indicates that osteoporotic fractures occur at an earlier age in Indians than in the West; hence, screening for osteoporosis should begin at an earlier age. FRAX can be used for fracture risk estimation; however, it may underestimate the risk of future fractures in our population and still needs validation. Maintaining optimum serum 25-hydroxyvitamin D levels is essential, which, in most cases, would require regular vitamin D supplementation. Pharmacotherapy should be guided by the presence/absence of vertebral/hip fractures or the severity of risk based on clinical factors, although bisphosphonates remain the first choice in most cases. Regular follow-up is essential to ensure adherence and response to therapy.

CONCLUSIONS

Implementation of the position statement in clinical practice is expected to improve the overall care of patients with osteoporosis in India.

The role, efficacy and outcome measures for teriparatide use in the management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a complex disease which can be associated with multiple morbidities and is challenging to treat. This review evaluates the literature on the role and efficacy of teriparatide (TPTD) as a treatment for MRONJ. The clinical, radiological, histopathological and serological parameters used to assess treatment response have been described. Electronic databases were searched to retrieve articles (April 2005 and April 2020) based on strict inclusion criteria. Seventeen articles were included in this review. Of the 91 patients treated; only six received TPTD as a standalone treatment. There were significant variations in defining treatment outcomes and measuring treatment response. The longest follow-up period was 26 months, and 12 studies failed to report follow-up. The overall quality of evidence is weak with potential for a high risk of bias, making it difficult to determine the efficacy of TPTD and its long-term effects. However, TPTD may play a role in the treatment of intractable MRONJ in osteoporotic patients or those unfit for surgery. Therefore, randomized clinical trials on larger patient cohorts with long-term follow-up is required to confirm efficacy, safety and inform treatment indications for TPTD in the treatment of MRONJ.

Current Evidence on Dental Implants Outcomes in Smokers and Nonsmokers: A Systematic Review and Meta-Analysis

This systematic review aims to answer the following PICO (Participants, Intervention, Comparison, and Outcome) question: “Does smoking increase the rates of implant failure and peri-implant marginal bone loss in patients with dental implants?” An extensive electronic search of the Cochrane Central Register of Controlled Trials, PubMed, Medline, Embase, and Web of Science databases and a subsequent hand search were performed. Only randomized controlled trial, controlled clinical trials, and prospective studies published up to January 2017 were included. For dichotomous outcomes, the effect estimates for smoking are expressed as odds ratios and 95% CIs. For continuous outcomes, weighted mean differences (WMDs) and 95% CIs are presented. Three randomized controlled trials and 7 prospective studies were included. The odds ratio for implant failure among smokers was 2.92 (95% CI, 1.76–4.83) (P < .001). First-year marginal bone loss in smokers ranged from 0.02 to 0.45 mm. In the nonsmokers, bone loss ranged from −0.08 to 0.42 mm. Nonsmokers lost significantly less bone during the first year (WMD = 0.11 mm, 95% CI. 0.03–0.19) and subsequent years (WMD = 0.11 mm, 95% CI, 0.03–0.19, P = .009). The available scientific evidence suggests that smoking is associated with significantly increased rates of implant failure and marginal bone loss.

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.

PTH prevents the adverse effects of focal radiation on bone architecture in young rats

Radiation therapy is a common treatment regimen for cancer patients. However, its adverse effects on the neighboring bone could lead to fractures with a great impact on quality of life. The underlying mechanism is still elusive and there is no preventive or curative solution for this bone loss. Parathyroid hormone (PTH) is a current therapy for osteoporosis that has potent anabolic effects on bone. In this study, we found that focal radiation from frequent scans of the right tibiae in 1-month-old rats by micro-computed tomography severely decreased trabecular bone mass and deteriorated bone structure. Interestingly, PTH daily injections remarkably improved trabecular bone in the radiated tibiae with increases in trabecular number, thickness, connectivity, structure model index and stiffness, and a decrease in trabecular separation. Histomorphometric analysis revealed that radiation mainly decreased the number of osteoblasts and impaired their mineralization activity but had little effects on osteoclasts. PTH reversed these adverse effects and greatly increased bone formation to a similar level in both radiated and non-radiated bones. Furthermore, PTH protects bone marrow mesenchymal stem cells from radiation-induced damage, including a decrease in number and an increase in adipogenic differentiation. While radiation generated the same amount of free radicals in the bone marrow of vehicle-treated and PTH-treated animals, the percentage of apoptotic bone marrow cells was significantly attenuated in the PTH group. Taken together, our data demonstrate a radioprotective effect of PTH on bone structure and bone marrow and shed new light on a possible clinical application of anabolic treatment in radiotherapy.

Denosumab: mechanism of action and clinical outcomes

AIMS

To describe the mechanisms of action of denosumab, a novel antiresorptive agent, contrasting it with other antiresorptive and anabolic osteoporosis treatments.

METHODS

Published papers related to the mechanism of action of approved osteoporosis treatments were sought through MEDLINE searches.

FINDINGS

Osteoporotic fractures carry a substantial burden of morbidity and mortality, but pharmacotherapy can prevent such fractures in high-risk individuals. Antiresorptive drugs (e.g. bisphosphonates, oestrogen, denosumab) reduce bone turnover by distinct mechanisms. Denosumab, a recently approved therapy, is a fully human monoclonal antibody that binds the cytokine RANKL (receptor activator of NFκB ligand), an essential factor initiating bone turnover. RANKL inhibition blocks osteoclast maturation, function and survival, thus reducing bone resorption. In contrast, bisphosphonates bind bone mineral, where they are absorbed by mature osteoclasts, inducing osteoclast apoptosis and suppressing resorption. These differences in mechanism influence both the onset and reversibility of treatment.

DISCUSSION

Effective pharmacotherapy is necessary for patients at high risk of fracture. Among the treatment options for postmenopausal osteoporosis, there are significant differences in mechanism and dosing. Denosumab acts by a novel mechanism and is administered twice yearly by subcutaneous injection. Identified by Osteoporosis Canada Clinical Practice Guidelines as a first-line agent for treatment of postmenopausal osteoporosis, denosumab represents an important addition to our treatment options.

Parathyroid hormone (1-34) compensates the negative effect of smoking around implants

OBJECTIVES

This study aimed to investigate the effect of Recombinant Human Parathyroid Hormone (PTH 1-34) on attenuating the influence of cigarette smoke on bone around titanium implants.

MATERIAL AND METHODS

Forty-eight female Wistar rats were used. At the beginning of the study, 15 animals were randomly assigned to Group 1 (control) and received subcutaneous injections of saline solution, three-times/week, after implant placement. The other animals received intermittent cigarette smoke inhalation (CSI), 60 days prior and 60 days after implant placement ( Al 2 O 3 -blasted titanium implants - 4.0 × 2.2 mm). After surgery, these animals were randomly assigned to: Group 2 - subcutaneous injections of saline solution, three-times/week (n = 16) and Group 3 - intermittent doses of PTH (1-34) (40 μg/Kg), three-times/week (n = 17). Animals were sacrificed 60 days after surgery, and degree of bone-to-implant contact (BIC), bone area (BA) within the limits of the threads and proportion of mineralized tissue (PMT) adjacent to the implants (500 μm wide zone) were separately obtained in cortical and cancellous bone.

RESULTS

Data analysis confirmed that CSI negatively affects bone around implants, as observed for BIC in cortical zone (Cohen's d (d) = -1.26) and for PMT in both zones (d = -6.09 and d = -4.46 for cortical and cancellous zones, respectively). In addition, in the presence of CSI, PTH (1-34) promoted the highest BIC in both regions and BA and PMT in cancellous bone (P < 0.05). The histometric parameter that was not influenced by both PTH and CSI (1-34) was BA in cortical bone (P > 0.05).

CONCLUSION

In the presence of cigarette smoke, a factor related to poor bone healing and low bone density, PTH (1-34) increased bone volume around implants.

Teriparatide vs. alendronate as a treatment for osteoporosis: changes in biochemical markers of bone turnover, BMD and quality of life

Background

We studied the use of teriparatide in postmenopausal women with severe osteoporosis.

Material/Methods

Two groups (A and B) of patients affected by severe osteoporosis (T-score ⩽−2.5 at bone mineral density were analyzed and 2 vertebral fractures on radiograph).

Group A was treated for 18 months with 20 μg/day of teriparatide. Group B was treated with bisphosphonates 70 mg/week. Every woman assumed 1 g of calcium and 800 IU of vitamin D3 daily. We evaluated the effects of therapy after 18 months (T18) from the beginning with bone turnover markers (alkaline phosphatase, procollagen type 1 N-terminal propeptide, and N-telopeptide cross-links) and dual-energy X-ray absorptiometry.

Results

Group A, at T18 procollagen type 1 N-terminal propeptide levels, increased 127%; bone alkaline phosphatase levels increased to 65%; N-telopeptide cross-links levels increased to 110%.

Group B, at T18 procollagen type 1 N-terminal propeptide levels, decreased to 74%; bone alkaline phosphatase levels decreased to 41%; N-telopeptide cross-links levels decreased to 72%.

After 18 months, lumbar bone mineral density increased to 12.4% and femoral bone mineral density increased to 5.2% in group A. Group B lumbar bone mineral density increased to 3.85% and femoral bone mineral density increased to 1.99%. Only a new vertebral fracture occurred in group A (2.4%), whereas 6 fractures occurred in group B (15.7%).

The quality of life questionnaire of the European Foundation for Osteoporosis (QUALEFFO) revealed a significant improvement in daily living, performed domestic jobs, and locomotor function in groups A and B.

Conclusions

The use of rhPTH in patients with severe osteoporosis offers more protection against fractures and improves the QoL more than bisphosphonates.

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.

Parathyroid hormone analogues in the treatment of osteoporosis

Osteoporosis is characterized by the occurrence of fragility fractures. Over the past years, various treatment options have become available, mostly antiresorptive agents such as bisphosphonates. However, antiresorptive therapy cannot restore bone mass and structure that has been lost due to increased remodeling. In this case, recombinant human parathyroid hormone (PTH) analogues-the full-length PTH(1-84) or the shortened molecule PTH(1-34), which is also known as teriparatide-present the possibility of increasing the formation of new bone substance by virtue of their anabolic effects. The bone formation induced by PTH analogues not only increases BMD or bone mass but also improves the microarchitecture of the skeleton, thereby leading to improved strength of bone and increased mechanical resistance. Controlled trials have shown that both analogues significantly reduce the incidence of vertebral fractures, and PTH(1-34) also reduces the risk of nonvertebral fractures. The need for daily self-injection and the higher cost compared with other forms of treatment limit the widespread use of PTH analogues. Nevertheless, treatment with PTH analogues should be considered in postmenopausal women and men with severe osteoporosis, as well as in patients on established glucocorticoid treatment with a high fracture risk. Concurrent therapy with antiresorptive agents should be avoided, but sequential therapy with these agents might consolidate the beneficial effects on the skeleton.

Osteoimmunology at the nexus of arthritis, osteoporosis, cancer, and infection

Over the past decade and a half, the biomedical community has uncovered a previously unappreciated reciprocal relationship between cells of the immune and skeletal systems. Work in this field, which has been termed "osteoimmunology," has resulted in the development of clinical therapeutics for seemingly disparate diseases linked by the common themes of inflammation and bone remodeling. Here, the important concepts and discoveries in osteoimmunology are discussed in the context of the diseases bridging these two organ systems, including arthritis, osteoporosis, cancer, and infection, and the targeted treatments used by clinicians to combat them.

Metabolism-guided design of short-acting calcium-sensing receptor antagonists

As part of a strategy to deliver short-acting calcium-sensing receptor (CaSR) antagonists, the metabolically labile thiomethyl functionality was incorporated into the zwitterionic amino alcohol derivative 3 with the hope of increasing human clearance through oxidative metabolism, while delivering a pharmacologically inactive sulfoxide metabolite. The effort led to the identification of thioanisoles 22 and 23 as potent and orally active CaSR antagonists with a rapid onset of action and short pharmacokinetic half-lives, which led to a rapid and transient stimulation of parathyroid hormone in a dose-dependent fashion following oral administration to rats. On the basis of the balance between target pharmacology, safety, and human disposition profiles, 22 and 23 were advanced as clinical candidates for the treatment of osteoporosis.

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.

Neuropeptide Y and sex hormone interactions in humoral and neuronal regulation of bone and fat

The hypothalamus regulates the skeleton and adipose tissue via endocrine mechanisms. Changes in sex steroid levels in menopause and aging are central to the associated changes in bone mass and adiposity. Whereas many of these effects occur via direct actions on osteoblasts or adipocytes, sex hormones can also mediate effects on bone and adipose tissue via interaction with neuronal pathways. A key hypothalamic regulator of bone and adipose tissue is neuropeptide Y (NPY), which coordinately influences these tissues via effects on neuroendocrine and sympathetic nervous output. Better understanding of the interaction between NPY and sex steroids in regulating skeletal and energy homeostasis could lead to more effective treatments for osteoporosis and obesity.

Mechanical stimulation and intermittent parathyroid hormone treatment induce disproportional osteogenic, geometric, and biomechanical effects in growing mouse bone

Mechanical loading and intermittent parathyroid (iPTH) treatment are both osteoanabolic stimuli and are regulated by partially overlapping cellular signaling pathways. iPTH has been shown clinically to be effective in increasing bone mass and reducing fracture risk. Likewise, mechanical stimulation can significantly enhance bone apposition and prevent bone loss, but its clinical effects on fracture susceptibility are less certain. Many of the osteogenic effects of iPTH are localized to biomechanically suboptimal bone surfaces, whereas mechanical loading directs new bone formation to high-stress areas and not to strain-neutral areas. These differences in localization in new tissue, resulting from load-induced versus iPTH-induced bone accumulation, should affect the relation between bone mass and bone strength, or "tissue economy." We investigated the changes in bone mass and strength induced by 6 weeks of mechanical loading and compared them to changes induced by 6 weeks of iPTH treatment. Loading and iPTH both increased ulnar bone accrual, as measured by bone mineral density and content, and fluorochrome-derived bone formation. iPTH induced a significantly greater increase in bone mass than loading, but ulnar bone strength was increased approximately the same amount by both treatments. Mechanical loading during growth can spatially optimize new bone formation to improve structural integrity with a minimal increase in mass, thereby increasing tissue economy, i.e., the amount of strength returned per unit bone mass added. Furthermore, exercise studies in which only small changes in bone mass are detected might be more beneficial to bone health and fracture resistance than has commonly been presumed.

The use of PTH in the treatment of osteoporosis

Anabolic drugs have recently widened therapeutic options in osteoporosis treatment, as they influence processes associated with bone formation to a greater extent and earlier than bone reabsortion. They positively affect a number of skeletal properties besides bone density, as intermittent administration of parathyroid hormone (PTH) results in an increase in the number and activity of osteoblasts leading to an increase in bone mass and improvement in skeletal architecture at both the trabecular and cortical bone. Human recombinant parathyroid hormone (hrPTH 1-84) and human recombinant PTH peptide 1-34 (teriparatide) belong to this group. The objective of this paper is to review PTH actions, benefits and adverse effects, action on biochemical markers, combination therapy with antiresorptive agents, impact of antiresorptive therapy prior to anabolic treatment, sequential treatment, and effect on glucocorticoid-induced osteoporosis.