Denosumab in patients with cancer and skeletal metastases: a systematic review and meta-analysis

The Risk of Medication-Related Osteonecrosis of the Jaw in Children: Guidance for Antiresorptive Use in Pediatric Patients

BACKGROUND

Antiresorptive targeted cancer therapies, such as denosumab and bisphosphonates, are used in adults, but their application in pediatric cancer is more recent. Side effects such as osteonecrosis of the jaw (ONJ) observed in adults have curtailed use of these medications in the pediatric population.

PURPOSE

This study assesses the frequency of ONJ, other side effects, and the indications for use of denosumab versus bisphosphonates in pediatric subjects.

STUDY DESIGN, SETTING, SAMPLE

A retrospective cohort study of pediatric subjects who underwent bisphosphonate or denosumab therapy at our institution from 2007-2023 was conducted. Subjects aged ≥ 18 years at therapy initiation were excluded.

INDEPENDENT VARIABLE

The independent variable was antiresorptive therapy divided into 2 groups, treatment with intravenous bisphosphonates or denosumab.

MAIN OUTCOME VARIABLE(S)

Primary outcomes were development of bisphosphonate-related and denosumab-related ONJ. Secondary outcomes included additional side effects.

COVARIATES

ONJ risk factors, subject demographics, indications for use, timing, duration, and cumulative dose of antiresorptive therapy were abstracted.

ANALYSES

Univariate and bivariate statistics were computed to describe the sample and measure associations between antiresorptive therapy and outcomes. P values < .05 conferred statistical significance.

RESULTS

The sample was composed of 178 subjects with a mean age of 11.7 ± 6.1 years. There were 14 (7.9%) and 164 (92.1%) subjects treated with denosumab and bisphosphonate therapies, respectively. There were 0 cases of ONJ across all subjects. The most common indication for treatment was adjuvant targeted therapy for aggressive tumors and malignancy (39.3%) followed by osteoporosis (14.6%). Subjects treated with denosumab had higher frequencies of hypercalcemia and severe bone pain than subjects treated with bisphosphonates, 28.6% versus 1.2% (P < .001) and 14.3% versus 0.00% (P < .001), respectively.

CONCLUSION AND RELEVANCE

While invasive dental procedures are ideally performed before antiresorptive treatment, our data suggest that bisphosphonates may be used safely in the pediatric population with low concern for ONJ. Our data also demonstrated bisphosphonates may have a more tolerable side effect profile than denosumab. If the perceived benefits are similar, we recommend using bisphosphonates as first-line therapy in children while reserving denosumab for refractory cases. Future studies will help determine long-term side effects and differences in efficacies of these medications.

Downregulation of osteoprotegerin in colorectal cancer cells promotes liver metastasis via activating tumor-associated macrophage

Osteoprotegerin (OPG) is a secreted cytokine that functions as a decoy receptor for receptor activator of nuclear factor kappa-B (RANK) ligand (RANKL). Anti-RANKL treatment for bone metastasis has been widely accepted for solid tumors. However, the mechanism of OPG-RANKL-RANK signaling in systemic colorectal cancer (CRC) metastasis remains unclear. In this study, we investigated the relevance and function of OPG expression in CRC liver metastasis. First, we performed in silico analysis using The Cancer Genome Atlas public database and found that lower OPG expression in CRC was associated with poor overall survival. Immunohistochemistry analyses using resected specimen from patients with CRC in our institute confirmed the result. Patient-matched primary CRC and liver metastases showed a significant downregulation of OPG expression in metastatic lesions. In CRC cell lines, OPG expression did not suppress cell proliferation and migration. However, OPG expression inhibited macrophage migration by suppressing the RANKL-RANK pathway. Moreover, in vivo mouse liver metastasis models showed that OPG expression in CRC cells suppressed liver metastases. In addition, treatment with an anti-RANKL neutralizing antibody also suppressed liver metastases. These results showed that downregulation of OPG expression in CRC cells promotes liver metastasis by activating tumor-associated macrophage, which can become a candidate for targeted therapy with anti-RANKL neutralizing antibody for CRC liver metastasis.

Combination of immunotherapy, radiotherapy and denosumab as the best approach even for NSCLC poor prognosis patients: a case report with strong response, prolonged survival and a review of literature

Non-Small Cell Lung Cancer (NSCLC) with bone metastasis and poor performance status has the worst prognosis even in strong PD-L1 expression patients. Treatment approach includes immuno- or chemo-immunotherapy, Radiotherapy (RT) and Bone-Targeted Therapy (BTT) but there is insufficient data to suggest the best time to use each of them, alone or in combination. Using an integrated and synergistic treatment strategy with immunotherapy, radiotherapy, and Denosumab as BTT is probably the best treatment planning for metastatic NSCLC for both good and poor performance status patients, although more data are needed to confirm this approach. Here we describe an interesting case report on patient with extensive bone involvement from NSCLC and PS >2 treated simultaneously with radiotherapy, immunotherapy and BTT, achieving an excellent clinical benefit, radiological and metabolic complete response, as a sort of Lazarus effect. We analyzed our result comparing with currently published data about radio-immunotherapy or immunotherapy and BTT combination even though there is no published experience about integration of all 3 treatments. Approval studies often do not represent real-world experience (RWE), so we analyzed data from both RWE and clinical trials.

The RANK-RANKL-OPG System: A Multifaceted Regulator of Homeostasis, Immunity, and Cancer

The RANK-RANKL-OPG system is a complex signaling pathway that plays a critical role in bone metabolism, mammary epithelial cell development, immune function, and cancer. RANKL is a ligand that binds to RANK, a receptor expressed on osteoclasts, dendritic cells, T cells, and other cells. RANKL signaling promotes osteoclast differentiation and activation, which leads to bone resorption. OPG is a decoy receptor that binds to RANKL and inhibits its signaling. In cancer cells, RANKL expression is often increased, which can lead to increased bone resorption and the development of bone metastases. RANKL-neutralizing antibodies, such as denosumab, have been shown to be effective in the treatment of skeletal-related events, including osteoporosis or bone metastases, and cancer. This review will provide a comprehensive overview of the functions of the RANK-RANKL-OPG system in bone metabolism, mammary epithelial cells, immune function, and cancer, together with the potential therapeutic implications of the RANK-RANKL pathway for cancer management.

Examination of Risk Factors and Expression Patterns of Atypical Femoral Fractures Using the Japanese Adverse Drug Event Report Database: A Retrospective Pharmacovigilance Study

Atypical femoral fracture (AFF) is a rare complication related to the use of bisphosphonates (BPs). Herein, we analyzed the risk factors and onset patterns of AFF using the Japanese Adverse Drug Event Report database and reported the findings. First, the independent risk factors for AFF were gender (female), high body mass index, and medical history of osteoporosis, arthritis, and systemic lupus erythematosus (SLE). Drug-related risk factors for AFF included BPs (i.e., alendronic acid, ibandronic acid, etidronic acid, zoledronic acid, minodronic acid, risedronic acid), denosumab, prednisolone, lansoprazole, rabeprazole, exemestane, letrozole, eldecalcitol, and menatetrenone. Therefore, it appears that AFF is influenced by a combination of patient backgrounds and drugs, and that the risk of developing AFF is particularly high in patients with fragile bones (e.g., osteoporosis, arthritis, and SLE). Second, in the analysis of AFF onset patterns, the onset of AFF from BPs and denosumab took a long time (>1 year) to develop. Analysis using a Weibull distribution showed wear-out failure-type AFF onset for BPs and denosumab, and both osteoporosis and cancer patients with long-term administration of these drugs showed a tendency to have an increased risk of onset. AFF developed earlier in osteoporosis patients with long-term administration of BPs and denosumab than in cancer patients.

Associated systemic diseases and etiologies of medication-related osteonecrosis of the jaw: a retrospective study of 265 surgical cases

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is one of the complications caused by various drugs. As there are increasing reports of MRONJ, it is important to diagnose and identify patients who have the potential risk of the disease. The aim of this study was to analyze the systemic diseases, etiology, and treatment results of MRONJ.

MATERIAL AND METHODS

A total of 265 MRONJ operations were reviewed retrospectively. This study included patients who were diagnosed as MRONJ and those who also received surgery, ranging from simple extraction to reconstruction with free flaps, from 2009 to 2021. Each patient's systemic disease and eitology and basic demographic information was taken into consideration.

RESULTS

The most common diseases related were osteoporosis (n = 127), breast cancer (n = 77), multiple myeloma (n = 27), prostate cancer (n = 26), and etc. (n = 12). The related causes of MRONJ were extraction (n = 138), implants (n = 40), and irritations by prosthesis (n = 29); however, 55 cases were occurred spontaneously. Out of 265 patients, 214 were women while 51 were men. The average age when the surgery took place was 67.7 and 69.8 years for male and female patients, respectively. Saucerization and sequestrectomy (n = 252) was the most common surgical treatment, followed by mandibulectomy (n = 12) and partial maxillectomy (n = 1). While 4 cases occurred in both jaws, 168 cases were in the mandible and 93 cases were in the maxilla.

CONCLUSION

Nearly 50 % of the MRONJ patients had osteoporosis and the other patients who received bone targeting agents parentral had bone metastasis of various cancers. Extraction is the most common related event for MRONJ.

Current comprehensive understanding of denosumab (the RANKL neutralizing antibody) in the treatment of bone metastasis of malignant tumors, including pharmacological mechanism and clinical trials

Denosumab, a fully humanized monoclonal neutralizing antibody, inhibits activation of the RANK/RANKL/OPG signaling pathway through competitive binding with RANKL, thereby inhibiting osteoclast-mediated bone resorption. Denosumab inhibits bone loss; therefore, it is used to treat metabolic bone diseases (including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis), in clinical practice. Since then, multiple effects of denosumab have been discovered. A growing body of evidence suggests that denosumab has a variety of pharmacological activities and broad potential in clinical diseases such as osteoarthritis, bone tumors, and other autoimmune diseases. Currently, Denosumab is emerging as a treatment for patients with malignancy bone metastases, and it also shows direct or indirect anti-tumor effects in preclinical models and clinical applications. However, as an innovative drug, its clinical use for bone metastasis of malignant tumors is still insufficient, and its mechanism of action needs to be further investigated. This review systematically summarizes the pharmacological mechanism of action of denosumab and the current understanding and clinical practice of the use of denosumab for bone metastasis of malignant tumors to help clinicians and researchers deepen their understanding of denosumab.

Gold nanoparticles as antiangiogenic and antimetastatic agents

Angiogenesis and metastasis are two interdependent cancer hallmarks, the latter of which is the key cause of treatment failure. Thus, establishing effective antiangiogenesis/antimetastasis agents is the final frontier in cancer research. Gold nanoparticles (GNPs) may provide disruptive advancements in this regard due to their intrinsic physical and physiological features. Here, we comprehensively discuss recent potential therapeutical strategies to treat angiogenesis and metastasis and present a critical review on the state-of-the-art in vitro and in vivo evaluations of the antiangiogenic/antimetastatic activity of GNPs. Finally, we provide perspectives on the contribution of GNPs to the advancement of cancer management.

Trends of denosumab-related publications in web of science

Denosumab is a human monoclonal antibody that targets nuclear factor-kappa B ligand and is highly effective in blocking bone resorption. Bibliometrics can intuitively show the research development process, research status, research hotspots and development trend of a certain topic for researchers. This study assessed the course of research and development for denosumab in terms of publications over the past 2 decades. Web of Science databases were searched to identify publications related to research on denosumab from January 1, 2005 to December 31, 2022. The VOS Viewer software (version 1.6.17) and Bibliometrix package in R (version 4.1.3) were used in this study. There were 5119 denosumab-related publications during this period. The total number of citations of denosumab-related publications reached 94917. The most articles were published in the field of Endocrinology Metabolism. As an international language, English remains the most popular language for writing papers. Five of the top ten institutions originated in the USA. Through the VOS Viewer analysis, we found that the relationships between Amgen Inc. with its collaborations were grouped into 4 clusters, the USA was the mainland for research and development on denosumab, closely collaborating with many other countries, such as Canada, Japan, England, and China. Wagman RB from USA was the most prolific author with 119 publications. The journal with the most publications was Osteoporosis International (481 publications). The most cited article was "Denosumab for Prevention of Fractures in Postmenopausal Women with Osteoporosis" with 2053 citations. The clinical trial comprised 6 of the 10 most frequently cited publications, and the rest consisted of reviews. The most frequent keywords for publications since January 1, 2014 were "prevention" and "management," indicating that a number of prevention and management measures have been developed to regulate the use of denosumab in treating osteoporosis. Our research provided a comprehensive review of denosumab-related publications, suggesting that the development of denosumab is a long process and numerous clinical trials have been conducted before applications in clinical settings.

American Association of Oral and Maxillofacial Surgeons' Position Paper on Medication-Related Osteonecrosis of the Jaws-2022 Update

Strategies for management of patients with, or at risk for, medication-related osteonecrosis of the jaws (MRONJ) - formerly referred to as bisphosphonate-related osteonecrosis of the jaws (BRONJ)-were set forth in the American Association of Oral and Maxillofacial Surgeons (AAOMS) position papers in 2007, 2009 and 2014. The position papers were developed by a committee appointed by the AAOMS Board of Trustees and comprising clinicians with extensive experience in caring for these patients, as well as clinical and basic science researchers. The knowledge base and experience in addressing MRONJ continues to evolve and expand, necessitating modifications and refinements to the previous position papers. Three members of the AAOMS Committee on Oral, Head, and Neck Oncologic and Reconstructive Surgery (COHNORS) and three authors of the 2014 position paper were appointed to serve as a working group to analyze the current literature and revise the guidance as indicated to reflect current knowledge in this field. This update contains revisions to diagnosis and management strategies and highlights the current research status. AAOMS maintains that it is vitally important for this information to be disseminated to other relevant healthcare professionals and organizations.

Osteonecrosis of the Jaw and Antiresorptive Agents in Benign and Malignant Diseases: A Critical Review Organized by the ECTS

CONTEXT

Antiresorptive therapy significantly reduces fracture risk in patients with benign bone disease and skeletal-related events (SREs) in patients with bone metastases (BM). Osteonecrosis of the jaw (ONJ) is a rare but severe condition manifested as necrotic bone lesion or lesions of the jaws. ONJ has been linked to the use of potent antiresorptive agents, termed medication-related ONJ (MRONJ).

OBJECTIVE

We aimed to identify the differences various aspects of MRONJ among distinct patient categories and provide recommendations on how to mitigate the risk and optimally manage MRONJ in each of them.

METHODS

A working group of the European Calcified Tissue Society (ECTS) and 2 experts performed an updated detailed review of existing literature on MRONJ incidence, characteristics, and treatment applied in bone diseases with variable severity of skeletal insult, ranging from osteoporosis to prevention of cancer treatment-induced bone loss and SREs in cancer patients with BM.

RESULTS

The risk for MRONJ is much higher in patients with advanced malignancies compared to those with benign bone diseases because of the higher doses and more frequent administration of antiresorptive agents in individuals with compromised general health, along with coadministration of other medications that predispose to MRONJ. The overall risk for MRONJ is considerably lower than the benefits in all categories of patients.

CONCLUSION

The risk for MRONJ largely depends on the underlying bone disease and the relevant antiresorptive regimen applied. Physicians and dentists should keep in mind that the benefits of antiresorptive therapy far outweigh the risk for MRONJ development.

Prevalence, Incidence Rate, and Risk Factors of Medication-Related Osteonecrosis of the Jaw in Patients With Osteoporosis and Cancer: A Nationwide Population-Based Study in Japan

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but severe adverse event of antiresorptive agents. However, the precise prevalence and factors associated with the development of MRONJ remain unknown. The present study was performed to describe the prevalence, incidence rate, and risk factors of developing MRONJ.

METHODS

We conducted a population-based retrospective cohort study using the National Database of Health Insurance, an administrative claims database of all patients in Japan. We identified patients who newly began using antiresorptive drugs from April 2015 to December 2018. The primary outcome was the development of MRONJ. We calculated the prevalence and incidence rate of MRONJ and performed a time-dependent Cox proportional hazard regression analysis to examine risk factors for developing MRONJ.

RESULTS

We identified 2,819,310 patients who newly used antiresorptive drugs during the study period. Of these patients, 2,664,104 (94.5%) had osteoporosis and 155,206 had cancer. Among the patients with osteoporosis, 1,603 (0.06%) developed MRONJ; the incidence rate was 22.9 per 100,000 person-years. Among the patients with cancer, 2,274 (1.47%) developed MRONJ; the incidence rate was 1,231.7 per 100,000 person-years. The occurrence of MRONJ was associated with poor oral conditions (including tooth extraction), age, male sex, drug type, concomitant drug use, comorbidities, cancer type, and geographic location.

CONCLUSIONS

The overall prevalence and incidence rate were low, but they were still higher than those in previous studies. Poor oral conditions were more closely related to the development of MRONJ than other factors. These findings suggest that improving poor oral hygiene may be essential to prevent MRONJ.

Risk Analysis of Denosumab-Induced Hypocalcemia in Bone Metastasis Treatment: Renal Dysfunction Is Not a Risk Factor for Its Incidence in a Strict Denosumab Administration Management System with Calcium/Vitamin D Supplementation

We have reported that a strict denosumab administration management system with oral calcium/vitamin D supplementation attenuates denosumab-induced hypocalcemia in 158 cancer patients with bone metastasis. In this report, 27.8% of the patients experienced hypocalcemia, including 0.6% with grade 2. So far, the risk factors for ≥grade 2 hypocalcemia incidence have been identified in denosumab-treated cancer patients, including patients without calcium/vitamin D supplementation. Therefore, the present study aimed to reveal the factors that affect all-grade hypocalcemia incidence with calcium/vitamin D supplementation and team medical care according to the management system. A receiver operating characteristic curve analysis suggested that the cutoff of baseline serum calcium level for all-grade hypocalcemia incidence was 9.3 mg/dL. Multivariate analysis revealed that age ≥65 years (odds ratio, 95% confidence interval: 2.57, 1.11-5.95, p = 0.03), grade 1 or higher serum alkaline phosphatase elevation (3.70, 1.71-8.00, p < 0.01), an adjusted serum calcium level of less than 9.3 mg/dL (3.21. 1.25-8.24, p = 0.02) at baseline, and co-administration of cytotoxic agents (2.33, 1.06-7.11, p = 0.03) are risk factors for the incidence of all-grade hypocalcemia. However, renal dysfunction, which has been suggested to be a risk factor in previous reports, was not a factor. In conclusion, we revealed the risk factors for all-grade hypocalcemia in calcium/vitamin D supplementation and awareness, as demonstrated by the management system. Moreover, renal dysfunction was not a risk factor in our strict denosumab administration management system. Our results support the value of early detection of hypocalcemia incidence to guide the selection of an appropriate management strategy.

Medication related osteonecrosis of the jaws (MRONJ): Factors related to recurrence after treatment with surgery and platelet rich plasma (PRP) placement

Background

Medication-related osteonecrosis of the jaws (MRONJ) is a well-known complication associated with antiresorptive and antiangiogenic therapies. The purpose of this study was to analyse if there is any predictive factor of recurrence after local debridement plus platelet rich plasma (PRP) placement in MRONJ patients.

Material and Methods

Seventy MRONJ patients treated at the department of Oral and Maxillofacial Surgery in La Paz Hospital (Madrid, Spain) were included in this retrospective study. All of them were treated surgically by local debridement and PRP placement. The observation period was between January 2012 and January 2019. Information regarding use, type, administration, and duration of therapy with BP/denosumab was recorded. The follow-up period ranged from 2-52 months. A descriptive analysis, a bivariate and a multivariate study were performed.

Results

Most of the patients were women (82.9%) between 50-70 years old (64.3%), with a stage II disease (74.3%). The therapy lasted more than 12 months in 54.8% of them. Zoledronic acid was the main antiresorptive used (44.3%), followed by oral administered BPs (29 patients, 41.4%) and denosumab (10 patients, 14.3%). Osteoporosis (48.6%), breast cancer (30%) and multiple myeloma (11.4%) were the main diseases because the patients were taking antirresorptives. 13 patients (18.6%) experienced recurrence. We found that breast cancer patients (p>0.0001), smokers (p>0.016), and administration of zoledronic acid (p>0.0001) were related to recurrence. After performing the multivariate model, we found that the only factor related to recurrence was smoking habit (Wald 3.837, p=0.05, OR 6.12).

Conclusions

recurrence after local debridement plus PRP placement in our MRONJ series affected to 18.6% of patients. It seems to be more frequent in breast cancer patients, smokers, and after zoledronic acid administration. Smoking habit was the only independent factor related to recurrence in our series.

Key words:Osteonecrosis of the jaw, recurrence, risk factor, bisphosphonates, zoledronic acid, denosumab, platelet rich plasma.

Medication-Related Osteonecrosis of the Jaw in Patients Treated Concurrently with Antiresorptive and Antiangiogenic Agents: Systematic Review and Meta-Analysis

Introduction

Medication-related osteonecrosis of the jaws (MRONJ) is a known adverse event related to the use of antiresorptive (AR) drugs. More recently, an association between antiangiogenic (AA) drugs and MRONJ has been suggested. This review aimed to investigate the overall prevalence and relative risk of MRONJ in patients treated concurrently with AA and AR agents in comparison with a single AA or AR drug.

Methods

A review protocol was registered with PROSPERO (ID: CRD42020214244). A systematic literature search, study selection, quality assessment, and data extraction were carried out following PRISMA guidelines. Random-effects meta-analysis models were used to summarize relative estimates for the outcomes, namely prevalence and relative risk of MRONJ. Exposure variable included type of drug, specifically AA and AR agents administered either concurrently or individually.

Results

Eleven studies were included in the final qualitative and quantitative syntheses. The overall pooled weighted prevalence of MRONJ with concurrent AA-AR drugs was 6% (95% CI: 3–8%), compared with 0% (95% CI: 0–0%) for AA only and 5% (95% CI: 0–10%) for AR only. However, high heterogeneity was noted among included studies. Retrospective cohort studies showed a higher pooled prevalence of 13% (95% CI: 10–17%) for concurrent AA-AR therapy. The pooled risk ratio for MRONJ revealed a risk with concurrent AA-AR drugs 2.57 times as high as with AR only (95% CI: 0.84–7.87); however, this difference was not statistically significant. Concurrent AA-AR drugs had a risk for MRONJ 23.74 times as high as with AA only (95% CI: 3.71–151.92).

Conclusions

High-quality, representative studies are needed for accurate estimation of relative risk of MRONJ with concurrent AA and AR therapy.

Life-threatening sustained hypocalcemia following Denosumab use in metastatic prostate cancer

INTRODUCTION

Prostate cancer is the second most frequently diagnosed cancer among men worldwide in 2020. Skeletal-related events (SRE) like pathologic fracture or spinal cord compression are commonly seen in metastatic prostate cancer. Denosumab, a monoclonal antibody, acts by inhibiting osteoclast-mediated bone resorption in bone metastasis from solid tumors and reduces bone turnover and destruction. However, there is an increased risk of life-threatening denosumab-induced hypocalcemia with an incidence of 0.1 to 12.8%.

CASE REPORT

Our patient is a 69-year-old man with widespread skeletal metastatic disease from primary prostate cancer who presented to the hospital complaining of generalized fatigue and joint pain. Due to severe debilitating low back pain secondary to osteochondral lesions, the patient was started on Denosumab 120 mg. On presentation, serum calcium was found to be severely low at 5.9 mg/dl (serum calcium level prior to Denosumab was 9.1 mg/dl).

MANAGEMENT AND OUTCOME

Denosumab was discontinued immediately, and the patient was started on IV calcium gluconate. Repeat serum calcium level continued to be low at 6.7 likely due to the long elimination half-life of Denosumab (25-30 days). He was transferred to a long-term acute care facility for long-term IV calcium replacement, where he succumbed to illness six weeks later.

DISCUSSION

Denosumab, an anti-resorptive treatment for skeletal metastasis from solid tumors, is shown to cause severe life-threatening hypocalcemia. The maximum serum drug level of Denosumab reaches 7-21 days after administration. Sustained hypocalcemia is rare and life-threatening. Clinicians should use this medication with caution due to its unpredictable side effect profile.

[Pharmaceutical Intervention According to Strict Management System Can Normalize Decreased Serum Calcium Level by Denosumab and Prevent Its Aggravation]

Denosumab is a fully monoclonal antibody against the receptor activator of nuclear factor kappa-B ligand (RANKL), and prevents skeletal-related events by bone metastasis. Hypocalcemia is the most typical adverse effect of denosumab use. We have developed a management system for the more efficient and safer management of denosumab administration, and evaluated pharmaceutical interventions for the better control of hypocalcemia. All pharmaceutical interventions in the system from April 2016 to March 2020 were retrospectively evaluated. We have also assessed the incidence of hypocalcemia in 158 patients who were administered denosumab for six months or more in the period. A total of 282 pharmaceutical interventions (7.0% of the total administration) were conducted. The most conducted intervention was regarding hypocalcemia, which involved the suspension of the injection and/or the increase of calcium and vitamin D supplement with 65% adoption and 17% temporary treatment suspensions. Other interventions were about hypercalcemia, request of laboratory examination and ordering supplements, dental consultation, and poor renal function. A total of 199 interventions (70.6%) were adopted, with 33 administrations suspended. The frequency of hypocalcemia was 27.8% with just one patient having grade 2 hypocalcemia, suggesting that there were no severe cases. Moreover, hypocalcemia was significantly normalized following pharmaceutical intervention and/or handling by physicians (p=0.02) according to the system. Conversely, the normalization rate in hypercalcemia did not differ according to the countermeasures. In conclusion, pharmaceutical interventions according to our management system benefit safe denosumab treatment, especially in severe hypocalcemia prevention.

Osteonecrosis of the jaw among patients with cancer treated with denosumab or zoledronic acid: Results of a regulator-mandated cohort postauthorization safety study in Denmark, Norway, and Sweden

BACKGROUND

Osteonecrosis of the jaw (ONJ) is an adverse effect of antiresorptive treatment. This study estimated incidence proportions and incidence rates of ONJ in cancer patients with bone metastases from solid tumors treated for the prevention of skeletal-related events in routine clinical practice.

METHODS

This cohort study in Denmark, Norway, and Sweden in 2011-2018 included 3 treatment cohorts: a denosumab inception cohort (DEIC), a zoledronic acid inception cohort (ZAIC), and a denosumab-switch cohort (DESC). The authors estimated 1- to 5-year incidence proportions and incidence rates of ONJ overall, by cancer site (breast, prostate, or other solid tumor), and by country. ONJ diagnoses were confirmed by adjudication.

RESULTS

There were 1340 patients in the DEIC, 1352 in the ZAIC, and 408 in the DESC. The median ages of the 3 cohorts were 70, 69, and 70 years, respectively; the proportions of men were 72.6%, 53.8%, and 48.3%, respectively; and the median follow-up was 19.8, 12.9, and 13.3 months, respectively. The 5-year incidence proportions of ONJ were 5.7% (95% confidence interval [CI], 4.4%-7.3%) in the DEIC, 1.4% (95% CI, 0.8%-2.3%) in the ZAIC, and 6.6% (95% CI, 4.2%-10.0%) in the DESC. The corresponding ONJ incidence rates per 100 person-years were 3.0 (95% CI, 2.3-3.7), 1.0 (95% CI, 0.6-1.5), and 4.3 (95% CI, 2.8-6.3). Incidence proportions and incidence rates were highest in patients with prostate cancer and in Denmark.

CONCLUSIONS

This study provides estimates of the risk of medically confirmed ONJ among patients initiating denosumab or zoledronic acid in routine clinical practice in 3 Scandinavian countries. The results varied by cancer site and by country.

LAY SUMMARY

Denosumab and zoledronic acid reduce the risk of bone fractures, pain, and surgery in patients with advanced cancers involving bone. Osteonecrosis of the jaw (ONJ)-death of a jawbone-is a known side effect of treatment with denosumab or zoledronic acid. The authors examined almost 2900 denosumab- or zoledronic acid-treated patients with cancer in Denmark, Norway, and Sweden. Over the course of 5 years, ONJ developed in 5.7% of the patients whose initial treatment was denosumab, in 1.4% of the patients whose initial treatment was zoledronic acid, and in 6.6% of the patients who switched from zoledronic acid to denosumab.

Denosumab-Induced Immune Hepatitis

Denosumab–Prolia®, Xgeva® (Amgen) is a fully human antibody to the receptor activator of the nuclear factor-K ligand (RANKL). Hepatotoxicity is extremely rare, with only one reported case of immune origin. We present a second case of hepatotoxicity resulting from an immune reaction to denosumab. A 43-year-old female was referred to the Endocrinology, Diabetes & Metabolism Department for treatment of low bone mineral density (BMD) following endocrine therapy with letrozole and lucrin because of breast cancer. She developed premature menopause at the age of 36 years when she underwent a left lumpectomy due to an infiltrating duct carcinoma of the breast (T1 NO MO) and was subsequently started on endocrine therapy. Denosumab was started to prevent osteoporosis. On the third year after starting on denosumab and one month after she received the last injection, she became ill. The routine biochemical analysis showed that the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) rose appreciatively to 10 times the upper limit of normal (ULN). The gamma-glutamyl transferase (GGT) level was elevated slightly to 67 U/L (0–38 U/L). The serum gamma-globulin level was elevated to 1.72 g/dL (0.7–1.6 gr/dl), while the total bilirubin (TB) and serum albumin levels were normal. A liver biopsy revealed a moderate to severe chronic inflammatory infiltrate containing MUM-1 positive plasma cells. In addition, numerous CD-3 positive small T lymphocytes and few CD-20 positive B lymphocytes and eosinophils were seen in the portal tracts. Moderate to severe interface hepatitis, bile duct proliferation and mild portal fibrosis were also identified. The results could be consistent with the diagnosis of drug-induced liver injury (DILI).

The safety profile of denosumab in oncology beyond the safety of denosumab as an anti-osteoporotic agent: still more to learn

INTRODUCTION

Initially endorsed as an antiosteoporotic agent, denosumab ‒ human monoclonal antibody inhibiting the receptor activator of nuclear factor kappa-B ligand (RANKL)‒ has currently shown an anticancer potential, rationalizing its exploitation in oncology. A prerequisite for leveraging denosumab in oncology is a favorable safety profile.

AREAS COVERED

The present review provides an overview of the adverse events of denosumab in oncology, with a focus on hypocalcemia, medication-related osteonecrosis of the jaw, atypical femoral fracture(s), post-denosumab vertebral fractures, increased risk of infections, and excess of second primary cancer. Representative studies addressing the safety and efficacy of denosumab compared to bisphosphonates in oncology are summarized. Critical gaps in the literature concerning the safety of denosumab in oncology are highlighted as opposed to plenty of available safety data on denosumab as an antiosteoporotic agent.

EXPERT OPINION

Despite the generally acceptable safety profile of denosumab in oncology, many issues remain unresolved. Further research is mandatory to counteract current challenges, namely: (i) validation of risk factors for adverse events; (ii) elucidation of the pathophysiology of the adverse events in search of actionable molecular pathways; (iii) illumination of the association of denosumab with increased risk of infections and/or second primary cancer; (iv) establishment of optimal diagnostic, and therapeutic protocols.

Prevalence of medication related osteonecrosis of the jaw in patients treated with sequential antiresorptive drugs: systematic review and meta-analysis

BACKGROUND

Antiresorptive drugs (ARD) are associated with a known serious adverse event, known as medication-related osteonecrosis of the jaws (MRONJ). Transition from one ARD to another has become common clinical practice with the advent of more potent or safer agents; however, the influence of sequential antiresorptive therapy as a risk factor for MRONJ has not been established.

OBJECTIVES

To investigate the prevalence of MRONJ in oncology or osteoporosis patients treated with two or more sequential ARDs as opposed to a single antiresorptive drug.

MATERIAL AND METHODS

Systematic electronic literature searches were conducted using Ovid MEDLINE, Ovid EMBASE, and Cochrane Central Register of Controlled Trials. Two review authors retrieved studies using pre-determined eligibility criteria and conducted quality assessment and data extraction. Fixed or random-effects meta-analysis models were used to summarize relative estimates for prevalence of MRONJ.

RESULTS

A total of 483 titles and abstracts were screened, and 18 full texts were retrieved for review. Twelve studies were included in the final qualitative and quantitative synthesis. Random effects meta-analysis models revealed a weighted pooled MRONJ prevalence of 19% (95% CI 10-27%) for sequential pamidronate-zoledronate therapy, 10% (95% CI 3-22%) for sequential ibandronate-zoledronate therapy. Pooled weighted prevalence of MRONJ was 13% (95% CI 3-22%) for sequential bisphosphonate-denosumab therapy while bisphosphonates only was 5% (95% CI 0-9%) and denosumab only was 4% (95% CI 3-5%).

CONCLUSIONS

The present systematic review suggests an increased prevalence of MRONJ associated with sequential ARD therapy for pamidronate-zoledronate and bisphosphonate-denosumab administration when compared to single ARD therapy.

Integration of denosumab therapy in the management of giant cell tumors of bone

A review of the literature indicated denosumab is gaining favorability in the oncology community, particularly with increasing frequency in GCTB. Will denosumab be the breakthrough GCTB treatment? Here, we provide a pertinent case example, a review of the literature regarding the history and basic science behind the use of denosumab for GCTB, highlight the newest insights into the dosing and duration of treatment, and note advancements in the field.

Meta-analysis of clinical trials to assess denosumab over zoledronic acid in bone metastasis

Background Bone metastases-induced skeletal complications result in reduced patient survival, lower quality of life, and an increase in healthcare costs. Previously, zoledronic acid (ZA) was the standard choice of treatment for bone metastases, but another drug, denosumab, has also shown promise. However, the clinical utility of these two drugs requires further exploration. Aim of the review Due to the lack of direct comparisons regarding the efficacy of these drugs in both solid tumors and multiple myeloma (MM), we herein tried to conduct a meta-analysis to compare their efficacy in parallel for bone metastases treatment in both solid tumor and MM patients. Methods Multiple databases including Cochrane Library, MEDLINE, EMBASE, and Web of Science were searched to identify randomized controlled trials (RCTs) reported up to March 2019 directly comparing denosumab with ZA in solid tumors and MM. Information about the following events was primarily searched: time to first on-study skeletal-related event (SRE), time to first and subsequent SREs, and overall survival. Information about secondary outcomes including disease progression, pain, health-related quality of life, and adverse events was also recorded. Results Overall, we analyzed data from four distinct RCTs including 7441 patients, and our analysis revealed that patients in the denosumab group had a significantly delayed incidence to the first and subsequent SREs. In addition, denosumab resulted in a higher incidence of hypocalcemia and osteonecrosis of the jaw (ONJ), and a lower incidence of renal toxicity and acute phase reactions, in comparison to ZA. Conclusion Overall, denosumab showed superiority in delaying the first and subsequent SREs, and hence seems to be a promising choice for managing bone metastases in both solid tumors and MM. However, it can induce a higher incidence of ONJ and hypocalcaemia, but these are preventable and manageable effects.

Osteonecrosis of the jaws associated with denosumab: Study of clinical and radiographic characteristics in a series of clinical cases

Background

The objective of this study was to describe the clinical and radiographic characteristics of our series of medication-related osteonecrosis of the jaws (ONJ) associated with denosumab.

Material and Methods

We presented 15 cases of ONJ associated with denosumab; 11 received treatment for their osteoporosis and four for cancer treatments. We recorded the most frequent clinical findings, symptoms and radiographic characteristics in our patient group, as well as local and systemic contributing factors.

Results

The mean time of treatment with denosumab was 23.83 ± 12.84 months. 40% of the patients had a previous history of treatment with bisphosphonates. The most common local factor was tooth extraction (11 cases; 73.3%), and in most cases there was necrotic bone exposure (13/15, 86.67%). Osteolysis, bone sclerosis and cortical erosion were the most common radiographic findings. Stage 1 was the most frequent, present in 60% of the cases.

Conclusions

In our patient group, most were in the early stages of ONJ.

Key words:Denosumab, osteonecrosis, jaws, radiology.

Hypocalcaemia following denosumab in prostate cancer: A clinical review

OBJECTIVES

Denosumab is often used in men with advanced prostate cancer to prevent skeletal-related events, but can be associated with severe hypocalcaemia. Our objective was to review the pathophysiology, identify risk factors and provide recommendations for prevention and management of denosumab-associated hypocalcaemia.

DESIGN

We reviewed the literature regarding denosumab-associated severe hypocalcaemia, defined as necessitating hospitalization for intravenous calcium treatment, in the context of prostate cancer.

PATIENTS

Men with prostate cancer with severe denosumab-associated hypocalcemia.

RESULTS

We identified 20 men with prostate cancer with severe denosumab-associated hypocalcemia, including the present case. Median age (range) was 70 years (45-86). All had skeletal metastases and presented with symptomatic hypocalcemia 16 days (4-35) after the initial (n = 18) or second (n = 2) denosumab treatment, with a serum total calcium of 1.36 mmol/L (1.13-1.91). The key risk factor was presence of active osteoblastic metastases, evidenced by elevated serum alkaline phosphatase, 838 U/L (58-2620) and supportive imaging. Other risk factors reported in some men included vitamin D deficiency (<50 nmol/L), 25-OH vitamin D 44 nmol/L (22-81), renal impairment, serum creatinine 103 μmol/L (62-1131) and hypomagnesaemia, 0.82 mmol/L (0.29-1.20). Men received intravenous calcium infusions for 16 days (1-90), and median total intravenous elemental calcium requirements were 3.17 g (0.47-26.65).

CONCLUSIONS

Denosumab treatment in men with metastatic prostate cancer can be associated with life-threatening hypocalcaemia requiring prolonged hospitalization for intravenous calcium treatment. Modifiable risk factors should be corrected before denosumab administration. In men with active osteoblastic metastases, consideration should be given to delay denosumab treatment until underlying disease activity is controlled, and/or be administered with close monitoring and proactive treatment with calcium and calcitriol.

Risk for Infections During Treatment With Denosumab for Osteoporosis: A Systematic Review and Meta-analysis

CONTEXT

Denosumab inhibits the receptor activator of nuclear factor κ-Β ligand, an immune system modulator. Safety endpoints including risk for infections were assessed as secondary outcomes in randomized controlled trials (RCTs) of the drug.

OBJECTIVE

To assess the risk of serious adverse events of infections (SAEI) in denosumab-treated patients.

DATA SOURCES

PubMed and Cochrane Central Register of Controlled Trials were searched up to May 27, 2019.

STUDY SELECTION

All RCTs of denosumab (60 mg every 6 months) versus any comparator were included. We excluded trials in cancer patients for prevention of skeletal-related events.

DATA EXTRACTION

Two reviewers independently applied selection criteria and extracted the data. Risk ratios (RR) with 95% confidence intervals (CI) were pooled using a fixed effect model. Sensitivity analysis was based on risk of bias.

DATA SYNTHESIS

Thirty-three studies (22 253 patients) were included. There was a higher incidence of SAEI during denosumab treatment versus any comparator (RR, 1.21; 95% CI, 1.04-1.40; I2 = 0%), mainly of ear, nose, and throat (RR, 2.66; 95% CI, 1.20-5.91) and gastrointestinal origin (RR, 1.43; 95% CI, 1.02-2.01). RR was similar in a sensitivity analysis based on adequate allocation concealment. The RR of any infection (RR, 1.03; 95% CI, 0.99-1.06) and infection-related mortality (RR, 0.50; 95% CI, 0.20-1.23) was comparable between groups.

CONCLUSIONS

A higher incidence of SAEI is demonstrated during treatment with denosumab in an osteoporosis dose. Nevertheless, the overall risk for any infection or related mortality is similar to comparator groups. These findings merit consideration before therapy initiation.

SEVERE, PROLONGED, DENOSUMAB-INDUCED HYPOCALCEMIA WITH RECOVERY AFTER 111 DAYS OF HIGH-DOSE CALCIUM SUPPLEMENTATION

Objective

Denosumab is a monoclonal antibody commonly used for the prevention of skeletal-related events in patients with bone metastases from solid tumors. Hypocalcemia is a known adverse effect with denosumab, and we present an unusual case where 2 hypocalcemic events occurred after 1 denosumab treatment.

Methods

A 76-year-old man recently diagnosed with prostate cancer with bone metastasis was given 120 mg denosumab subcutaneously due to extensive bone disease.

Results

The patient experienced denosumab-induced hypocalcemia induced by a single denosumab dose which was resolved after 14 days of multiple doses of intravenous calcium gluconate and oral calcium and vitamin D replacement. However, the patient returned with acute kidney injury and severe hypocalcemia (corrected calcium of 6.9 mg/dL) without any additional dose of denosumab. The recovery following the second episode of hypocalcemia was much longer than the initial episode in this patient.

Conclusion

To our knowledge, this is the first reported case of an additional episode of hypocalcemia following a single denosumab dose. This case highlights the importance of close monitoring of renal function and serum electrolytes following the resolution of denosumab-induced hypocalcemia.

Pharmacokinetics, pharmacodynamics, safety, and tolerability of single-dose denosumab in healthy Chinese volunteers: A randomized, single-blind, placebo-controlled study

Background

Denosumab is a fully human monoclonal antibody against receptor activator of nuclear factor kappa-B ligand, a cytokine essential for the formation, function and survival of osteoclasts. This study assessed the pharmacokinetics, pharmacodynamics, safety and tolerability of single-dose denosumab (60 and 120 mg) in healthy Chinese volunteers.

Methods

This randomized (3:3:2), single-blind, placebo-controlled study enrolled healthy Chinese volunteers to receive single subcutaneous injection of denosumab 60 mg, 120 mg, or placebo. Study consisted of screening period (up to 21 days), treatment and assessment period (19 weeks), and an end-of-study visit (at week 26). Denosumab pharmacokinetics and pharmacodynamics parameters were estimated using non-compartmental analysis. Safety and tolerability were assessed throughout the study.

Results

A total of 63 volunteers received the study treatment and 62 (98.4%) completed the study. Denosumab serum concentrations peaked at around Day 10 with dose-proportional increase from 60 mg to 120 mg. The mean terminal half-life of denosumab 60 mg and 120 mg was 15 days and 26 days, respectively. The serum C-terminal cross-linking telopeptide of type I collagen concentration-time profiles were similar (>80% decrease within 5 days) between denosumab 60 mg and 120 mg groups. The most commonly reported adverse event (AE) was decreased blood calcium levels (denosumab 60 mg, n = 13; denosumab 120 mg, n = 13; placebo, n = 1); however only one volunteer had calcium level below the abnormality value of potential clinical importance and none of the volunteers developed symptoms of hypocalcemia. The majority of AEs were of mild to moderate intensity. There were no deaths, serious AEs, or withdrawal from study due to AEs. No clinically significant findings in vital signs or electrocardiogram were observed.

Conclusions

Both denosumab 60 mg and 120 mg were well tolerated with no new safety concerns identified in healthy Chinese volunteers with similar pharmacokinetics and pharmacodynamics profiles to that of Caucasians.

Trial registration

ClinicalTrial.gov NCT02135640

Understanding the Progression of Bone Metastases to Identify Novel Therapeutic Targets

Bone is one of the most preferential target site for cancer metastases, particularly for prostate, breast, kidney, lung and thyroid primary tumours. Indeed, numerous chemical signals and growth factors produced by the bone microenvironment constitute factors promoting cancer cell invasion and aggression. After reviewing the different theories proposed to provide mechanism for metastatic progression, we report on the gene expression profile of bone-seeking cancer cells. We also discuss the cross-talk between the bone microenvironment and invading cells, which impacts on the tumour actions on surrounding bone tissue. Lastly, we detail therapies for bone metastases. Due to poor prognosis for patients, the strategies mainly aim at reducing the impact of skeletal-related events on patients' quality of life. However, recent advances have led to a better understanding of molecular mechanisms underlying bone metastases progression, and therefore of novel therapeutic targets.

The RANK/RANKL/OPG system in tumorigenesis and metastasis of cancer stem cell: potential targets for anticancer therapy

The molecular triad involving receptor activator of nuclear factor kβ (RANK)/RANK ligand (RANKL)/osteoprotegerin cytokine system has been well implicated in several physiological and pathological processes including bone metabolism, mammary gland development, regulation of the immune function, tumorigenesis and metastasis of cancer stem cell, thermoregulation, and vascular calcification. However, this review aimed to summarize several original and up-to-date articles focusing on the role of this signaling system in cancer cell development and metastasis as well as potential therapeutic agents targeting any of the three tumor necrotic factor super family proteins and/or their downstream signaling pathways. The RANK/RANKL axis has direct effects on tumor cell development. The system is well involved in the development of several primary and secondary tumors including breast cancer, prostate cancer, bone tumors, and leukemia. The signaling of this triad system has also been linked to tumor invasiveness in the advanced stage. Bone is by far the most common site of cancer metastasis. Several therapeutic agents targeting this system have been developed. Among them, a monoclonal antibody, denosumab, was clinically approved for the treatment of osteoporosis and cancer-related diseases.

Case-Based Review of Osteonecrosis of the Jaw (ONJ) and Application of the International Recommendations for Management From the International Task Force on ONJ

Osteonecrosis of the jaw (ONJ) has been associated with antiresorptive therapy in both oncology and osteoporosis patients. This debilitating condition is very rare and advances in diagnosis and management may now effectively reduce the risk of its development and offer valuable treatment options for affected patients. This paper provides a case-based review of ONJ and application of the International Task Force on ONJ (referred to as the "Task Force") recommendations for the diagnosis and management of ONJ. The Task Force was supported by 14 international societies and achieved consensus from representatives of these multidisciplinary societies on key issues pertaining to the diagnosis and management of ONJ. The frequency of ONJ in oncology patients receiving oncology doses of bisphosphonate (BP) or denosumab is estimated at 1%-15%, and the frequency in the osteoporosis patient population receiving much lower doses of BP or denosumab is estimated at 0.001%-0.01%. Although the diagnosis of ONJ is primarily clinical, imaging may be helpful in confirming the diagnosis and staging. In those with multiple risk factors for ONJ for whom major invasive oral surgery is being planned, interruption of BP or denosumab therapy (in cancer patients) is advised, if possible, before surgery, until the surgical site heals. Major oral surgery in this context could include multiple extractions if surgical extractions are required, not simple forceps extractions. ONJ development may be reduced by optimizing oral hygiene and postoperatively using topical and systemic antibiotics as appropriate. Periodontal disease should be managed before starting oncology doses of BP or denosumab. Local debridement may be successful in disease unresponsive to conservative therapy. Successful surgical intervention has been reported in those with stage 3 disease; less severe disease is best managed conservatively. Teriparatide may be helpful in healing ONJ lesions and may be considered in osteoporosis patients at a high fracture risk in the absence of contraindications. Resumption of BP or denosumab therapy following healing of ONJ lesions is recommended, and there have not been reports of subsequent local recurrence.

Design and methods for a Scandinavian pharmacovigilance study of osteonecrosis of the jaw and serious infections among cancer patients treated with antiresorptive agents for the prevention of skeletal-related events

Objective

Osteonecrosis of the jaw (ONJ) is a recognized complication of potent antiresorptive therapies, especially at the doses indicated to prevent skeletal complications for cancer patients with bone metastases. This paper describes the rationale and methods for a prospective, post-authorization safety study of cancer patients treated with antiresorptive therapies.

Methods

As part of a comprehensive pharmacovigilance plan, developed with regulators’ input, the study will estimate incidence of ONJ and of serious infections among adult cancer patients with bone metastases treated with denosumab (120 mg subcutaneously) or zoledronic acid (4 mg intravenously, adjusted for renal function). Patients will be identified using routinely collected data combined with medical chart review in Denmark, Sweden, and Norway. Followup will extend from the first administration of antiresorptive treatment to the earliest of death, loss-to-follow-up, or 5 years after therapy initiation. Results will be reported for three treatment cohorts: denosumab-naïve patients, zoledronic acid-naïve patients, and patients who switch from bisphosphonate treatment to denosumab. ONJ cases will be identified in three newly established national ONJ databases and adjudicated by the committee that functioned during the XGEVA^® clinical trials program.

Conclusion

This study will provide a real world counterpart to the clinical trial-estimated risks for ONJ and serious infections for cancer patients initiating denosumab or zoledronic acid. The establishment of ONJ databases in the three Scandinavian countries will have potential benefits outside this study for the elucidation of ONJ risk factors and the evaluation of ONJ treatment strategies.

New anti-resorptives and antibody mediated anti-resorptive therapy

The ageing population and an increase in both the incidence and prevalence of cancer pose a healthcare challenge, some of which is borne by the orthopaedic community in the form of osteoporotic fractures and metastatic bone disease. In recent years there has been an increasing understanding of the pathways involved in bone metabolism relevant to osteoporosis and metastases in bone. Newer therapies may aid the management of these problems. One group of drugs, the antibody mediated anti-resorptive therapies (AMARTs) use antibodies to block bone resorption pathways. This review seeks to present a synopsis of the guidelines, pharmacology and potential pathophysiology of AMARTs and other new anti-resorptive drugs. We evaluate the literature relating to AMARTs and new anti-resorptives with special attention on those approved for use in clinical practice. Denosumab, a monoclonal antibody against Receptor Activator for Nuclear Factor Kappa-B Ligand. It is the first AMART approved by the National Institute for Health and Clinical Excellence and the US Food and Drug Administration. Other novel anti-resorptives awaiting approval for clinical use include Odanacatib. Denosumab is indicated for the treatment of osteoporosis and prevention of the complications of bone metastases. Recent evidence suggests, however, that denosumab may have an adverse event profile similar to bisphosphonates, including atypical femoral fractures. It is, therefore, essential that orthopaedic surgeons are conversant with these medications and their safe usage.

TAKE HOME MESSAGE

Denosumab has important orthopaedic indications and has been shown to significantly reduce patient morbidity in osteoporosis and metastatic bone disease.

Resection and microvascular reconstruction of bisphosphonate-related osteonecrosis of the jaw: The role of microvascular reconstruction

BACKGROUND

Current treatment guidelines caution against osseous reconstruction using free flap tissue to treat bisphosphonate-related osteonecrosis of the jaw (BRONJ). The primary rationale for this stance is the theoretical risk of nonunion and recurrence of disease within the reconstruction. Emerging evidence suggests that these theoretical risks may be overestimated. We performed a literature review of this procedure for the treatment of advanced BRONJ. We also present a new case report of resection and microvascular reconstruction in a 58-year-old man with stage III BRONJ.

METHODS

A MEDLINE search was performed to gather all reports of maxillary and mandibular reconstruction using free tissue flap transfer for BRONJ. Inclusion criteria were confirmed stage II or III BRONJ, free tissue transfer and reconstruction, and reported complications. Articles were excluded if they contained only local flap reconstruction, wound closure without reconstruction, or osteoradionecrosis. Outcomes from our case report were added to the analysis.

RESULTS

We identified 10 articles that met criteria. Adding our case, we identified 40 cases of free flap reconstruction. The rate of nonunion was 5% (2 of 40). Fistulas formed in 4 cases (10%). BRONJ recurred in 2 cases (5%).

CONCLUSION

Complication rates after free flap microvascular reconstruction in BRONJ seem acceptable. Nonunion is relatively rare and should not be the sole reason to recommend against free flap reconstruction. A randomized clinical trial would help clarify the role of this procedure in refractory BRONJ; however, we believe that segmental resection and microvascular reconstruction is a viable option in select cases of BRONJ. © 2016 Wiley Periodicals, Inc. Head Neck 38:1278-1285, 2016.

Concept, diagnosis and classification of bisphosphonate-associated osteonecrosis of the jaws. A review of the literature

Background

Bisphosphonates (BPs) and other antiresorptive agents such as denosumab are widely prescribed for the treatment of osteoporosis and are also used in patients with multiple myeloma and metastatic breast or prostate cancer for avoiding bone reabsorption and fractures that result in increased morbidity-mortality among such individuals.

Material and Methods

We made a bibliographic search to analyze the concept, diagnosis and the different classifications for bisphosphonate-associated osteonecrosis of the jaws.

Results

Osteonecrosis of the jaws (ONJ) is an important complication of exposure to BPs or other antiresorptive agents, and although its prevalence is low, it can pose management problems. The definition, diagnosis and classification of osteonecrosis have evolved since Marx reported the first cases in 2003.

Conclusions

The present study offers a literature review and update on the existing diagnostic methods and classification of the disorder, with a view to facilitating earlier and more effective treatment.

Key words:Osteonecrosis, jaws, bisphosphonates.

A RANKL Wrinkle: Denosumab-Induced Hypocalcemia

The human monoclonal antibody denosumab inhibits osteoclast-mediated bone resorption by binding to receptor activator of nuclear factor κB ligand (RANKL), which is upregulated by tumor cells. Denosumab is indicated to prevent skeletal-related events (SREs) from osteoporosis and metastatic bone disease. We report a case of denosumab-induced hypocalcemia to highlight potential toxicity and treatment considerations. A 66-year-old man with prostate cancer, small cell lung cancer, and bone metastases presented with fatigue, weakness, and muscle spasm. Sixteen days prior, he received cycle 6 of cisplatin and etoposide, leuprolide, and denosumab (120 mg subcutaneously). His examination demonstrated a slight resting tremor, normal strength, and negative Chvostek sign. Laboratory analysis revealed hemoglobin, 8.0 g/dL; total calcium, 5.2 mg/dL (pre-denosumab, 8.9 mg/dL); and magnesium, 0.7 mg/dL. He initially received two units packed red blood cells, intravenous calcium and magnesium, and vitamin D. During his hospitalization, he required multiple doses of intravenous and oral calcium, magnesium, and vitamin D. Despite ongoing oral supplementation, his post-discharge serum calcium fluctuated significantly, requiring close monitoring and frequent dose adjustments. Denosumab's unique antiresorptive properties yield fewer SREs. The trade-off is increased hypocalcemia risk, which may be severe and require aggressive, prolonged supplementation and monitoring.

Two Cases of Sarcoma Arising in Giant Cell Tumor of Bone Treated with Denosumab

Giant cell tumor (GCT) of bone is a generally benign, but often locally aggressive, neoplasm of bone, with a propensity for recurrence. Sarcomatous transformation is rare and typically occurs with a history of recurrences and radiation treatment. Denosumab, an inhibitor of the RANK ligand involved in bone resorption in GCT, is increasingly used in treatment of recurrent or unresectable giant cell tumor of bone. We report two cases of sarcomatous transformation of GCT to osteosarcoma in patients receiving denosumab. One was a 59-year-old male with a 12-year history of GCT and multiple recurrences taking denosumab for 2.5 years. The second case was in a 56-year-old male with a seven-year history of GCT taking denosumab for six months. Review of the literature shows one case report of malignant transformation of GCT in a patient being treated with denosumab. As the use of denosumab for treatment of GCT will likely increase, larger, controlled studies are needed to ascertain whether denosumab may play a role in malignant transformation of giant cell tumor of bone.

Quantitative pharmacology of denosumab in patients with bone metastases from solid tumors

Denosumab (XGEVA®) is a recombinant, fully human IgG2 monoclonal antibody directed against the receptor activator of nuclear factor kappa-B ligand (RANKL) that prevents differentiation of osteoclast precursors into mature osteoclasts and acceleration of bone resorption, resulting in the inhibition of osteoclast activation. Denosumab is indicated for the prevention of skeletal-related events (SREs) in adult patients with bone metastases from solid tumors at the dose of 120 mg administered subcutaneously (SC) every 4 weeks. This review is focused on describing its target-mediated disposition and direct inhibitory effect on bone resorption, as well as the modeling and simulation techniques used to integrate the PKPD information collected during clinical development of denosumab. In addition, this review further discusses the clinical relevance of patient covariate effects on denosumab systemic exposure, target engagement and downstream pharmacodynamics biomarkers, and the rationale for dosing regimen selection for Phase 3 studies. Phase 3 clinical studies demonstrated that denosumab was superior to zoledronic acid in inhibiting bone resorption and, consequently, delaying the time to first SRE by a median of 8.2 months in patients with bone metastases from solid tumors. Thus, denosumab may be considered a better alternative treatment than zoledronic acid for the prevention of SRE in patients with bone metastases from solid tumors.

Short-term and long-term effects of osteoporosis therapies

Progress continues to be made in the development of therapeutics for fracture prevention. Bisphosphonates are now available orally and intravenously, often as inexpensive generics, and remain the most widely used interventions for osteoporosis. The major safety concern associated with the use of bisphosphonates is the development of femoral shaft stress fractures and, although rare, this adverse event affords the principal rationale for restricting bisphosphonate therapy to those individuals with femoral T-scores <-2.5, and for providing drug holidays in those individuals requiring therapy for >5 years. Newer antiresorptive therapies, in the form of denosumab and cathepsin K inhibitors, might increase efficacy and possibly circumvent some of the safety concerns associated with bisphosphonate use (for example, gastrointestinal and renal complications). The combination of teriparatide with antiresorptives markedly increases effects on BMD; new anabolic agents are also very promising in this regard. However, whether or not these changes in BMD translate into improved efficacy of fracture prevention remains to be determined. Vitamin D is important for the prevention of osteomalacia, but does not influence BMD or fracture risk in patients not deficient in vitamin D. The balance of risks and benefits of calcium supplementation is contentious, but patients should be encouraged to adhere to a balanced diet aimed at maintaining a healthy body weight. Consideration of a patient's risk of falling, and its mitigation, are also important. In this Review, I summarize the short-term and long-term effects of osteoporosis therapies.

Correlation of baseline biomarkers with clinical outcomes and response to fulvestrant with vandetanib or placebo in patients with bone predominant metastatic breast cancer: An OCOG ZAMBONEY sub-study

Background

Bone metastases are common in women with breast cancer and often result in skeletal related events (SREs). As the angiogenic factor vascular endothelial growth factor (VEGF) regulates osteoclast activity and is associated with more extensive bone metastases and SRE risk in metastatic breast cancer, we hypothesized that blockade of VEGF signaling could be a therapeutic strategy for inhibiting bone metastases progression and possibly prolonging overall (OS) or progression-free survival (PFS). The Zamboney trial was a randomized placebo-controlled study designed to assess whether patients with bone predominant metastatic breast cancer benefited from addition of the VEGF receptor (VEGFR) targeting agent, vandetanib, to endocrine therapy with fulvestrant. As a companion study, evaluation of biomarkers and their potential association with response to vandetanib or SRE risk was performed.

Methods

Baseline overnight fasted serum from enrolled patients was analyzed for levels of various putative biomarkers including; VEGF-A, soluble (s)VEGFR2, sVEGFR3, transforming growth factor (TGF)-β1 and activinA by ELISA. Spearman correlation coefficients and Wilcoxon rank sum tests were used to investigate potential relationships between biomarker values and baseline clinical parameters. Prognostic and predictive ability of each marker was investigated using Cox proportional hazards regression with adjustments for treatment and baseline strata of serum CTx (<400 versus ≥400 ng/L).

Results

Of 129 enrolled patients, serum was available for analysis in 101; 51 in vandetanib and 50 in placebo arm. Mean age amongst consenting patients was 59.8 years. Clinical characteristics were not significantly different between patients with or without serum biomarker data and serum markers were similar for patients by treatment arm. Baseline sVEGFR2 was prognostic for OS (HR=0.77, 95% CI=0.61–0.96, p=0.020), and although a modest association was observed, it was not significant for PFS (HR=0.90, 95% CI=0.80–1.01, p=0.085) nor time to first SRE (HR=0.82, 95% CI=0.66–1.02, p=0.079). When interaction terms were evaluated, sVEGFR2 was not found to be predictive of response to vandetanib, although a modest association remained with respect to PFS (interaction p=0.085). No other marker showed any significant prognostic or predictive ability with any measured outcome.

Conclusions

In this clinical trial, sVEGFR2 appeared prognostic for OS, hence validation of sVEGFR2 should be conducted. Moreover, the role of sVEGFR2 in breast cancer bone metastasis progression should be elucidated.

•

Baseline VEGF, sVEGFR3, TGF-β or activinA were not associated with clinical outcomes in patients treated with fulvestrant in conjunction with vandetanib or placebo.

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Baseline sVEGFR2 was modestly associated with clinical outcomes including PFS, OS and time to first skeletal event.

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Increased baseline sVEGFR2 was associated with improved clinical outcomes in this study sample.

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These findings support the need for future studies of the role of sVEGFR2 in bone metastasis progression.