Weekly teriparatide injections successfully treated advanced bisphosphonate-related osteonecrosis of the jaws

Current Trends in Adjuvant Therapies for Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a refractory disease, and a standard protocol for its treatment has not yet been established. In addition, owing to the old age of MRONJ patients and various complications, treatment goals focus on relieving the symptoms and improving the quality of life. For this reason, different treatments such as conservative, surgical, and adjunctive treatments have been attempted. In particular, adjunctive treatment, which is effective for promoting healing and reducing recurrence, is gaining increasing interest, and several studies and clinical trials related to it have been published. Representative adjuvant therapies include teriparatide, recombinant human bone morphogenetic protein-2, hyperbaric oxygen, photobiomodulation and platelet concentrates. All have generally shown beneficial effects; however, no standard protocol for adjunctive treatment exists. Therefore, in this literature review, we briefly summarized the different adjuvant therapies and reviewed clinical reports to help decide whether to use adjuvant therapies in treating patients with MRONJ.

Parathyroid Hormone 1 Receptor Signaling in Dental Mesenchymal Stem Cells: Basic and Clinical Implications

Parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) are two peptides that regulate mineral ion homeostasis, skeletal development, and bone turnover by activating parathyroid hormone 1 receptor (PTH1R). PTH1R signaling is of profound clinical interest for its potential to stimulate bone formation and regeneration. Recent pre-clinical animal studies and clinical trials have investigated the effects of PTH and PTHrP analogs in the orofacial region. Dental mesenchymal stem cells (MSCs) are targets of PTH1R signaling and have long been known as major factors in tissue repair and regeneration. Previous studies have begun to reveal important roles for PTH1R signaling in modulating the proliferation and differentiation of MSCs in the orofacial region. A better understanding of the molecular networks and underlying mechanisms for modulating MSCs in dental diseases will pave the way for the therapeutic applications of PTH and PTHrP in the future. Here we review recent studies involving dental MSCs, focusing on relationships with PTH1R. We also summarize recent basic and clinical observations of PTH and PTHrP treatment to help understand their use in MSCs-based dental and bone regeneration.

Effective ancillary role and long-term course of daily or weekly teriparatide treatment on refractory medication-related osteonecrosis of the jaw: a clinical case series

Medication-related osteonecrosis of the jaw (MRONJ) is a potentially severe adverse side effect of antiresorptive agents. However, withdrawal of such agents in patients with osteoporosis may increase the risk of fracture. The treatment of MRONJ is challenging, and standard treatment guidelines have yet to be established. In this study, the aim was to find out whether adjuvant daily or weekly teriparatide (TPTD) injections were beneficial for exposed bony MRONJ lesions compared with standard conservative management. We also studied the complications and the patients' response to TPTD therapy. We enrolled 27 patients (January 2012 - December 2016) with chronic and refractory MRONJ. There were four men and 23 women (85% female). Nine patients who did not select TPTD therapy for several reasons formed the non-TPTD group; the remaining 18 were randomly assigned to the daily (n=9) or weekly (n=9) groups. All patients in both groups continued standard conservative therapy in addition to their daily or weekly subcutaneous injection of TPTD (20 μg or 56.5 μg, respectively). We evaluated the complications of TPTD and its benefits. Three patients in the daily group did not complete the study, resulting in six patients in the daily group, nine in the weekly group, and nine in the non-TPTD group in the final analysis. The exposed bone was completely covered with normal mucosa in all patients in the TPTD groups, and the healing period was shorter than that in the non-TPTD group. No patient had complications of atypical fractures of the femoral head. Daily and weekly TPTD treatment resulted in a shortened treatment period compared with standard conservative therapy, with no increase in the rate of complications or worsening of osteoporosis.

The Treatment of Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review with a Pooled Analysis of Only Surgery versus Combined Protocols

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction of antiresorptive and antiangiogenic agents, and it is also a potentially painful and debilitating condition. To date, no specific studies have prospectively evaluated the efficacy of its treatment and no robust standard of care has been established. Therefore, a systematic review (2007–2020) with a pooled analysis was performed in order to compare MRONJ surgical techniques (conservative or aggressive) versus combined surgical procedures (surgery plus a non-invasive procedure), where 1137 patients were included in the pooled analysis. A statistically significant difference in the 6-month improvement rate, comparing combined conservative surgery versus only aggressive (91% versus 72%, p = 0.05), was observed. No significant difference regarding any group with respect to the 6-month total resolution rate (82% versus 72%) was demonstrated. Of note, conservative surgery combined with various, adjuvant, non-invasive procedures (ozone, LLLT or blood component + Nd:YAG) was found to achieve partial or full healing in all stages, with improved results and the amelioration of many variables. In conclusion, specific adjuvant treatments associated with minimally conservative surgery can be considered effective and safe in the treatment of MRONJ, although well-controlled studies are a requisite in arriving at definitive statements

Local RANKL delivery improves socket healing in bisphosphonate treated rats

Medication related osteonecrosis of the Jaws (MRONJ) is a severe complication of antiresorptive and anti-angiogenic medications. Osteoclast inhibition is central in MRONJ pathogenesis. Here, we investigated if local application of RANKL (a key molecule in osteoclast activation) could enhance osteoclast generation and improve extraction socket healing in the presence of bisphosphonates. Thirty Wistar-Han rats received one saline or 66 μg/kg zoledronate (ZA) i.p. dose before surgery. A week later, mandibular molars were extracted bilaterally. Collagen tapes infused with water or RANKL were placed in the extraction sockets of 60 hemimandibles of veh (veh/RANKL-, veh/RANKL+) or ZA treated rats (ZA/RANKL-, ZA/RANKL+). Rats were euthanized 3 or 12 days after surgery. Animals euthanized at 12 days received two additional veh or ZA injections. Clinical, radiographic and histologic assessments were performed. Visually, at the 3-day timepoint, no sockets demonstrated complete healing. At the 12-day timepoint, sockets of veh/RANKL- and veh/RANKL+ rats showed intact mucosa, while mucosal defects were noted in ZA/RANKL- rats. Importantly, ZA/RANKL+ sockets showed absence of bone exposure. RANKL delivery increased bone healing in the ZA/RANKL+ sites 12 days after extraction compared to the ZA/RANKL- sites. Histologically, at the 3-day timepoint, ZA/RANKL- sockets demonstrated extensive bone exposure and osteonecrosis. In contrast, ZA/RANKL+ rats showed granulation tissue coverage and significantly reduced osteonecrosis, similar to the veh groups. Importantly, in the ZA/RANKL+ group, osteoclasts attached to the bone surface and osteoclast numbers were higher compared to ZA/RANKL- sites. At the 12-day timepoint, persistent osteonecrosis and bone exposure were detected in the sockets of ZA/RANKL- animals. Contrary, ZA/RANKL+ rats demonstrated socket epithelialization and reduced osteonecrosis. Significantly more total and bony attached osteoclasts persisted in the ZA/RANKL+ vs the ZA/RANKL- group. We present a novel approach towards improving socket healing, in the presence of ZA, by enhancing osteoclastic numbers and attachment through local RANKL application. Our approach is clinically applicable and could improve treatment outcomes of patients on high-dose ZA therapy.

Molecular Targeted Therapy for the Bone Loss Secondary to Pyogenic Spondylodiscitis Using Medications for Osteoporosis: A Literature Review

Pyogenic spondylodiscitis can cause severe osteolytic and destructive lesions in the spine. Elderly or immunocompromised individuals are particularly susceptible to infectious diseases; specifically, infections in the spine can impair the ability of the spine to support the trunk, causing patients to be bedridden, which can also severely affect the physical condition of patients. Although treatments for osteoporosis have been well studied, treatments for bone loss secondary to infection remain to be elucidated because they have pathological manifestations that are similar to but distinct from those of osteoporosis. Recently, we encountered a patient with severely osteolytic pyogenic spondylodiscitis who was treated with romosozumab and exhibited enhanced bone formation. Romosozumab stimulated canonical Wnt/β-catenin signaling, causing robust bone formation and the inhibition of bone resorption, which exceeded the bone loss secondary to infection. Bone loss due to infections involves the suppression of osteoblastogenesis by osteoblast apoptosis, which is induced by the nuclear factor-κB and mitogen-activated protein kinase pathways, and osteoclastogenesis with the receptor activator of the nuclear factor-κB ligand-receptor combination and subsequent activation of the nuclear factor of activated T cells cytoplasmic 1 and c-Fos. In this study, we review and discuss the molecular mechanisms of bone loss secondary to infection and analyze the efficacy of the medications for osteoporosis, focusing on romosozumab, teriparatide, denosumab, and bisphosphonates, in treating this pathological condition.

Pathogenesis and multidisciplinary management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a serious side effect of bone-modifying agents and inhibits angiogenesis agents. Although the pathogenesis of MRONJ is not entirely clear, multiple factors may be involved in specific microenvironments. The TGF-β1 signalling pathway may have a key role in the development of MRONJ. According to the clinical stage, multiple variables should be considered when selecting the most appropriate treatment. Therefore, the prevention and management of treatment of MRONJ should be conducted in patient-centred multidisciplinary team collaborative networks with oncologists, dentists and dental specialists. This would comprise a closed responsibility treatment loop with all benefits directed to the patient. Thus, in the present review, we aimed to summarise the pathogenesis, risk factors, imaging features, clinical staging, therapeutic methods, prevention and treatment strategies associated with MRONJ, which may provide a reference that can inform preventive strategies and improve the quality of life for patients in the future.

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.

Enhancement of peri-implant bone formation via parathyroid hormone administration in a rat model at risk for medication-related osteonecrosis of the jaw

Purpose

Dental implant-associated medication-related osteonecrosis of the jaw has been frequently reported in patients administered bisphosphonates (BPs) to prevent osteoporosis. The aim of this study was to investigate the effect of intermittent administration of parathyroid hormone (PTH) on peri-implant bone in the maxillae of ovariectomized rats systemically administered BPs.

Methods

Thirty 8-week-old female Sprague-Dawley rats were randomly divided into 3 groups. The OVX-ZP group included ovariectomized rats administered 60 µg/kg of zoledronate once a week for 6 weeks and 30 µg/kg PTH after implant installation. The OVX-Z group included ovariectomized rats administered 60 µg/kg of zoledronate once a week for 6 weeks and saline after implant installation, and the control group included rats that underwent a sham operation and were then administered saline. Rats were sacrificed 4 weeks after implant placement for histomorphometric and micro-computed tomography (CT) analyses.

Results

The average bone area percentage was greater in the OVX-ZP group than in the OVX-Z group (53.4%±4.0% vs. 28.9%±9.5%, P=0.01). The bone-to-implant contact ratio was 50.8%±1.4% in the OVX-ZP group and 16.9%±2.4% in the OVX-Z group (P=0.012). The average bone volume ratio as shown on micro-CT was 31.3%±19.8% in the OVX-ZP group and 19.4%±9.3% in the OVX-Z group (P=0.045). The OVX-ZP and OVX-Z groups displayed similar trabecular thickness (0.06±0.004 mm vs. 0.06±0.002 mm) (P>0.05) and trabecular separation (0.21±0.02 mm vs. 0.29±0.13 mm) (P>0.05). However, the number of trabeculae in the OVX-ZP group was significantly higher than that in the OVX-Z group (4.3±1.33/mm³ vs. 2.2±0.19/mm³) (P=0.024).

Conclusions

The present findings indicate that intermittently-administered PTH can promote peri-implant bone formation and suggest that PTH administration may aid in effective treatment for medication-related osteonecrosis of the jaw after dental implantation.

A comparative effectiveness pilot study of teriparatide for medication-related osteonecrosis of the jaw: daily versus weekly administration

We studied the effectiveness of teriparatide (TPTD) for treating medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis and examined differences in the clinical outcomes following daily versus weekly TPTD. The outcomes were significantly improved in the entire patient series and the daily group.

PURPOSE

Teriparatide (TPTD) treatment for Stage II-III medication-related osteonecrosis of the jaw (MRONJ) in osteoporotic patients has yielded promising results in uncontrolled studies. The daily administration and the weekly administration of TPTD have been reported to improve outcomes in MRONJ. Herein, we sought to identify differences in the clinical outcomes of MRONJ patients treated with daily TPTD versus weekly TPTD.

METHODS

We enrolled 13 patients and randomly assigned them to receive either of two treatments: 1×/week 56.5-μg TPTD injection for 6 months (weekly group; n = 6 patients after 1 dropout), or 20-μg TPTD injection daily for 6 months (daily group; n = 6 patients). Patients in both groups received conventional therapy plus intensive antibiotic therapy as necessary. We compared the changes in the patients' clinical stage of MRONJ, bone metabolism, percentage of bone formation, and bone turnover markers between the weekly and daily groups.

RESULTS

TPTD treatment with MRONJ led to partial remission or complete remission in 5 daily-group patients and 3 weekly-group patients. The MRONJ stage was significantly improved from baseline to 6 months of treatment in the entire series of 12 patients (p = 0.008); the weekly group did not show significant improvement, but the daily group did (p = 0.01).

CONCLUSIONS

This study provides the first comparison of clinical outcomes between MRONJ patients who received daily or weekly TPTD injections. Six months of treatment with TPTD realized a significant improvement of MRONJ stage in both the entire patient series and the daily group.

Treatment of Medication-Related Osteonecrosis of the Jaw Around the Dental Implant With a Once-Weekly Teriparatide: A Case Report and Literature Review

Managing medication-related osteonecrosis of the jaw (MRONJ) around a dental implant can be difficult. Although conservative treatment of MRONJ is recommended as the first-line form of management, many patients exhibit no improvement. The human recombinant parathyroid hormone teriparatide has recently been introduced for the management of MRONJ. Teriparatide is effective in the treatment of postmenopausal osteoporosis and is the only US Food and Drug Administration-approved anabolic agent that directly affects osteoblast function and contributes to bone remodeling. Herein we describe a case of MRONJ in an 85-year-old woman who was successfully treated with teriparatide. Teriparatide was administered once per week without any surgical interventions such as a sequestrectomy. Compared with most recently reported cases involving daily treatment with teriparatide, once-weekly administration of teriparatide may minimize side effects and patient discomfort. Once-weekly teriparatide application without sequestrectomy may be effective in the management of MRONJ around a dental implant.

Anabolic agents: what is beyond osteoporosis?

Osteoporosis is a common skeletal disorder characterized by low bone mass, which leads to reduced bone strength and an increased risk of fractures. Anabolic agents have been shown to improve bone mass and decrease fracture risk in osteoporosis patients by directly stimulating osteoblasts to produce new bone. Currently, two anabolic agents are available in the USA: recombinantly produced teriparatide (TPTD), which is the fully active (1-34) amino active sequence of human parathyroid hormone (PTH), and abaloparatide (APTD), a synthetic analog of parathyroid hormone-related peptide (PTHrP). At present, both agents are approved only for treatment of patients with osteoporosis at high risk of fracture. Nonetheless, their anabolic properties have led to off-label application in additional settings which include spine fusion, osteonecrosis of the jaw, arthroplasty, and fracture healing. In this article, we summarize available scientific literature regarding the efficacy, effectiveness, and safety of TPTD in these off-label settings.

The influence of zoledronate and teriparatide on gamma delta T cells in mice

Background/purpose

Few studies have investigated the possibility that bisphosphonate-related osteonecrosis of the jaw (BRONJ) might reflect an immune response; however, gamma delta T cells have been shown to significantly decline in the blood of BRONJ patients. Additionally, there have been some reports of teriparatide usage for the treatment of BRONJ. In this study, we compared the effects of zoledronate and teriparatide on lymphocyte populations and inflammatory cytokine production in mice.

Materials and methods

Thirty female ICR mice were divided into three groups (n = 10 each): a vehicle, a zoledronate, and a teriparatide group. Drugs were administered for 8 weeks in each group. Lymphocytes in the blood and thymus were analyzed and femurs were used for histological observation and lymphocytes analysis of bone marrow. Cytokines were measured in separated serum using Milliplex^® multiplex immunoassay analysis.

Results

Zoledronate decreased the T cell number in the bone marrow. Additionally, serum levels of interleukin (IL)-2, IL-7, IL-12, IL-15 and RANTES, which are cytokines that affect T cell activation, differentiation and/or proliferation, were significantly lower in zoledronate treated mice. Conversely, teriparatide treatment induced an increase in gamma delta T cells in peripheral blood.

Conclusion

Gamma delta T cells in the bone marrow are expected to decrease with zoledronate treatment and increase with teriparatide treatment. If BRONJ involves a loss of gamma delta T cells in the circulation or bone marrow, then the increase in gamma delta T cells that is induced by teriparatide may account for its ability to resolve BRONJ.

Medication-Related Osteonecrosis of the Jaw: Basic and Translational Science Updates

In the late 1990s and the early 2000s, bisphosphonates had become the clinical pillar of excellence for treating metabolic bone disease, and thus their connection with osteonecrosis of the jaw (ONJ) caused significant concern. Over the past decade, progress has been made in understanding what is now referred to as medication-related ONJ (MRONJ), because of its connections to agents other than bisphosphonates, although in many respects the progress has been slow. This review highlights the key basic science and translational (animal) studies in the area of MRONJ and suggests areas of focus as the field moves into the next decade.

Intraoperative detection of viable bone with fluorescence imaging using Visually Enhanced Lesion Scope in patients with bisphosphonate-related osteonecrosis of the jaw: clinical and pathological evaluation

There is no standard surgical protocol of bisphosphonate-related osteonecrosis of the jaws (BRONJ), because of the impossibility to visualize this feature intraoperatively. The aim of this study was to introduce how to provide preoperative labeling of the viable bone with minocycline bone fluorescence technique (MBFT) by using VELscope® and investigate histopathologically.

INTRODUCTION

The American Association of Oral and Maxillofacial Surgeons (AAOMS) and the Japanese Society of Oral and Maxillofacial Surgeons (JSOMS) now recommend a more conservative treatment strategy. There is no standard surgical protocol of bisphosphonate-related osteonecrosis of the jaws (BRONJ) because of the impossibility to visualize this feature intraoperatively. The aim of this study was to introduce a mechanism providing preoperative labeling of a viable bone using minocycline bone fluorescence technique (MBFT) with VELscope® and to histopathologically investigate.

METHODS

This report describes a surgical technique used in six patients with BRONJ who underwent jawbone resection under minocycline bone fluorescence imaging using VELscope®. Subsequently, we investigated and compared the clinical findings using VELscope® and histopathological findings.

RESULTS

Histopathological examinations showed that the non-fluorescent moiety was consistent with the BRONJ lesions.

CONCLUSIONS

The surgical treatments that were exactly performed using MBFT with VELscope® offered successful management of BRONJ. This bone fluorescence helped to define the margins of resection, thus improving surgical therapy for extended osteonecrosis.

A systematic review on the use of daily subcutaneous administration of teriparatide for treatment of patients with osteoporosis at high risk for fracture in Asia

This systematic review aimed to examine the evidence for teriparatide in Asia for osteoporosis with a high fracture risk and for exploratory (unapproved) bone-related indications. MEDLINE (1946+), EMBASE (1966+), and ClinicalTrials.gov (2008+) were searched (16 August 2013); all studies of daily subcutaneous teriparatide 20 μg for bone-related conditions from China, Hong Kong, Japan, Republic of Korea, Philippines, Singapore, and Taiwan were included. Evidence on efficacy/safety was retrieved primarily from randomized controlled trials (10 publications) of postmenopausal women from Japan and China. In these studies, teriparatide was well tolerated; subjects had significantly greater increases in lumbar spine bone mineral density (BMD) from baseline compared with placebo, antiresorptive agents, or elcatonin/calcitonin; bone turnover markers increased from baseline and were sustained at elevated levels during teriparatide treatment. Few studies reported fracture risk, pain, or quality of life; one study showed a lower incidence of new-onset vertebral fracture with teriparatide versus antiresorptive agents. Nonrandomized studies (nine publications, one unpublished trial) conducted mainly in Taiwan, Japan, and the Republic of Korea provided supporting data for efficacy. The exploratory (unapproved) use of teriparatide (17 publications) for fracture healing and osteonecrosis of the jaw was described primarily in case reports. The clinical effectiveness of teriparatide for treatment of postmenopausal women with osteoporosis who are at high risk of fracture in Asia is focused primarily on improvements in BMD and tolerability. Recommended additional studies may include assessment of fracture risk and the effect of teriparatide on pain, quality of life, and mortality in Asia.

Temporal correlation between bisphosphonate termination and symptom resolution in osteonecrosis of the jaw: a pooled case report analysis

PURPOSE

To investigate whether termination of bisphosphonates (BPs) affects resolution of bone exposure and symptomatic disease in patients with established medication-related osteonecrosis of the jaw (MRONJ).

PATIENTS AND METHODS

The studied population included 84 patients with established MRONJ who discontinued BP therapy before treatment (n = 21), at treatment initiation (n = 38), or later (or never) in the treatment course (n = 25). These 3 groups were compared using Kaplan-Meier curves and log-rank tests for differences in the respective times to resolution of 1) bone exposure for any treatment modality, 2) bone exposure not requiring radical surgery, and 3) disease symptoms.

RESULTS

Patients who continued BPs after the start of treatment exhibited significantly delayed resolution of symptoms (median 12 months; 95% confidence interval 8 to 15) compared with those who discontinued BPs before (3 months; 2 to 5) and at (6 months; 3 to 7) presentation (P < .005).

CONCLUSIONS

Independent of treatment modality and MRONJ stage at presentation, discontinuing BP before or at treatment initiation is associated with faster resolution of MRONJ symptoms compared with continuing the drug throughout jaw treatment. Patients should be counseled that continuing their BP medication after an established MRONJ diagnosis (compared to stopping the BP at diagnosis) may delay resolution of maxillofacial symptoms by approximately 6 months.

Postmenopausal osteoporosis

PURPOSE OF REVIEW

The aim of this study is to provide a thorough updated review of the diagnosis and treatment of postmenopausal osteoporosis.

RECENT FINDINGS

There have been several important findings in the field of postmenopausal osteoporosis over the past 1-2 years. Fewer morphometric vertebral fractures were found in women treated for 6 years with zoledronic acid compared with those who stopped treatment after 3 years. Longer duration of bisphosphonate therapy is associated with a higher risk of atypical femur fractures. Combination therapy with teriparatide and denosumab appears to increase bone mineral density to a greater extent than either therapy alone in postmenopausal women at high risk for fracture. There are several novel therapies under investigation for the treatment of osteoporosis, which are in various stages of development. Nonadherence to osteoporosis therapies continues to be a major problem in clinical practice.

SUMMARY

There are numerous effective pharmacologic treatment options for postmenopausal osteoporosis. Bisphosphonate drug holidays continue to be an area of significant debate.