Mayo clinic consensus statement for the use of bisphosphonates in multiple myeloma

The use of bone-modifying agents in multiple myeloma

Multiple myeloma is a hematological neoplasm characterized by abnormal proliferation of plasma cells in the bone marrow and is usually associated with increased bone pain and skeletal-related events such as pathological fracture and/or spinal cord compression. Myeloma bone disease results in changes in the bone-marrow microenvironment evidenced by increased osteoclastic activity and/or decreased osteoblastic activity, which negatively affect quality of life. Treatment of myeloma bone disease includes bisphosphonates or denosumab (bone-modifying agents). These agents do not induce the formation of new bone or repair existing bone damage, but they can decrease bone pain and the risk of pathological fracture. While these agents improve quality of life, it is not known whether they improve overall survival. This review focuses on different classes of bone-modifying agents, their mechanisms of action, time of initiation, duration of therapy, and potential survival benefits.

Prognosis by cancer type and incidence of zoledronic acid-related osteonecrosis of the jaw: a single-center retrospective study

PURPOSE

Survival time after bisphosphonate use has been increasingly recognized to be associated with the incidence of medication-related osteonecrosis of the jaw (MRONJ); however, this has not been elucidated sufficiently in the literature. This study aimed to clarify the incidence of MRONJ and the corresponding survival rate of patients treated with zoledronic acid (ZA) for each type of cancer and obtain useful information for the oral/dental supportive care of cancer patients.

METHODS

We evaluated 988 patients who were administered ZA at our hospital; among them, 862 patients with metastatic bone tumors or myeloma were included.

RESULTS

The median survival time (MST) after ZA initiation was 35, 34, 8, 41, 12, and 6 months for patients with breast, prostrate, lung, myeloma, renal, and other cancers, respectively. Patients with cancers that had a short survival time (lung and other cancers [MST = 8 and 6 months, respectively] and cancers with MST < 10 months) did not develop MRONJ; this could be attributed to the shorter duration of ZA administration. The cumulative incidence of MRONJ in breast cancer, prostate cancer, and multiple myeloma was related to the frequency of anti-resorptive drug use and the increased risk over time. In renal cancer, the cumulative incidence of MRONJ increased early, although the MST was 12 months.

CONCLUSION

For the dentists in charge of dental management, it is essential to be aware of prognosis-related factors, predict MRONJ risk for each cancer treatment, and use risk prediction in dental management planning, particularly for cancers with non-poor prognosis.

Supportive care in multiple myeloma: Current practices and advances

Supportive care in multiple myeloma (MM) can have a major impact on quality of life and the survival outcomes of MM patients. In this review, we will focus on disease and treatment related toxicities experienced by MM patients and what are the best approaches to date to help mitigate the effects. We will specifically focus on a practical approach to managing bone disease, thrombosis, infection risk, peripheral neuropathy, dermatologic complications, gastrointestinal and ocular toxicities, and fatigue in MM.

Management of Myeloma Manifestations and Complications: The Cornerstone of Supportive Care: Recommendation of the Canadian Myeloma Research Group (formerly Myeloma Canada Research Network) Consensus Guideline Consortium

Multiple myeloma (MM) is a hematological cancer associated with significant symptomatic burden. Bone disease, renal insufficiency, cytopenias, infection, and peripheral neuropathy, among other disease manifestations and complications, impair patients' quality of life. The Canadian Myeloma Research Group Consensus Guideline Consortium, formerly Myeloma Canada Research Network Consensus Guideline Consortium, proposes national consensus recommendations for the management of MM-related manifestations and complications. To address the needs of Canadian physicians and people living with MM across the country, this document focuses on the improvement and maintenance of patient care by clarifying best-practice approaches for the prevention, detection and management of disease manifestations and complications. The Canadian Myeloma Research Group Consensus Guideline Consortium will periodically review the recommendations herein and update as necessary.

Supportive Care in Multiple Myeloma

PURPOSE OF REVIEW

As novel therapies are expanding the life expectancy of patients with multiple myeloma, appropriate supportive care has become critical in the management of these patients. This review aims to outline the key principles of supportive care of patients with myeloma, including management of bone disease, renal disease, anemia, peripheral neuropathy, infections, and venous thromboembolism.

RECENT FINDINGS

The results from large randomized, controlled trials on the use of high-cutoff hemodialysis in the removal of free light chains in renal disease and the use of levofloxacin in the prevention of infections have recently been published. These results, along with updated guidelines from professional societies on the use of bisphosphonates and erythropoietin stimulating agents, have provided guidance on more effective management strategies for myeloma patients. Integration of these updated guidelines and supportive care strategies into clinical practice will help to ensure quality of life for patients with myeloma.

Frequent occurrence of hypophosphatemia among multiple myeloma patients treated with elotuzumab: a single clinic retrospective study

The purpose of this single-center retrospective study was to determine the incidence of decreased blood phosphorus levels and hypophosphatemia among multiple myeloma (MM) patients treated with elotuzumab. Hypophosphatemia, which is defined as a serum phosphorus concentration < 2.5 mg/dL, leads to complications ranging from muscle weakness and disorientation to seizures and heart failure. A total of 23 MM patients receiving care in a clinic specializing in treatment of MM from July 2018 to March 2020 and treated with an elotuzumab-containing therapy were evaluated, and 9 were investigated for this study. Elotuzumab was given at 10 mg/kg weekly for the first two treatment cycles (28 days/cycle), followed by 10 mg/kg every other week for all subsequent cycles. Four different elotuzumab combination therapies were administered: 1) elotuzumab and dexamethasone 2) elotuzumab, lenalidomide and dexamethasone 3) elotuzumab, pomalidomide and dexamethasone and 4) elotuzumab, carfilzomib, pomalidomide, and dexamethasone. Phosphorous levels were determined at a median of every 13 days at intervals ranging from once weekly to once monthly until a phosphate supplement was prescribed to the patient or when elotuzumab treatment was discontinued. We found that regardless of elotuzumab combination therapy, all patients treated showed decreased phosphorus levels after initiating elotuzumab treatment with reductions ranging from 12.5% to 44.1% below baseline. Six participants (67%) demonstrated an average serum phosphorus at or below 2.5 mg/dL after starting elotuzumab therapy. This retrospective study suggests that hypophosphatemia commonly occurs among MM patients receiving elotuzumab-containing therapies.

Changing face of medication-related osteonecrosis of the jaw: Sheba Medical Center experience-fifteen years

INTRODUCTION

Our aim is to track the development of the epidemiological characteristics in patient populations diagnosed with MRONJ at the Sheba Medical Center.

MATERIALS AND METHODS

The files of patients diagnosed with MRONJ from 2003 until December 2017 were retrieved. Data on demographics, medical background, type and duration of drug use and triggering events at presentation was collected.

RESULTS

The study included 448 patients, 336 females and 112 males. A decrease in the proportion of multiple myeloma patients (p < 0.05) and an increase in the proportion of patients with bone metastases of solid tumors has been observed recently. An increase in the proportion of cases in osteoporosis patients compared with oncology patients is evident (p < 0.01). Overtime a higher proportion of patients presented at an earlier stage of MRONJ (p < 0.01).

CONCLUSIONS

As a result of changes in treatment protocols and increased awareness of oncology caregivers, including referral and consultation with Oral Medicine specialists, there has been a change in the demographics and presentation of the disease.

Therapeutic Dimensions of Bisphosphonates: A Clinical Update

Bisphosphonates (BPs) are a commonly used class of drugs for the treatment of bone disorders. An extensive review of BPs with their clinical efficacy and safety profile is unavailable. This study aimed to review the available literature on BPs, summarize their role in clinical therapy, and emphasize their safety profile. Authors reviewed the existing literature using the Google Scholar, PubMed, and Micromedex databases and analyzed the collected articles. BPs are the preferred medication for osteoporosis and other similar conditions owing to their efficient antiosteoclastic activity. Few of them are available in oral dosage forms; hence, they are patient-friendly. The mechanism of action, common adverse effects and their clinical applications, precautions and warnings pertaining to the route of administration, and safety profiles have been discussed in this manuscript. The common adverse effects are majorly related to the gastrointestinal, cardiovascular, and endocrine system. Upon chronic usage, patients may experience serious problems like osteonecrosis of the jaw and atypical bone fractures. Although BPs are effective and safe, they may cause GI adverse effects and rare cases of osteonecrosis. Patient counseling could prove beneficial in early identification and prevention of the adverse effects associated with BPs.

The limitations of today’s clinical guidance: Atypical femoral fracture and long-term bone-modifying agents in the oncology setting

While bone-modifying agents such as bisphosphonates and denosumab are crucial to preventing skeletal-related events in patients with bone metastases, the optimal duration remains undefined. Extended duration may be associated with adverse effects such as osteonecrosis of the jaw and atypical femoral fracture. Although uncommon, atypical femoral fracture represents a serious consequence of prolonged bone-modifying agent use and are characterized by a prodrome and distinct radiographic findings. The oncology setting encompasses a unique set of atypical femoral fracture risk factors and considerations, with hormonal therapy in early stage disease, bone metastases in the advanced setting, and new targeted agents that may affect bone homeostasis. As outcomes in cancer treatment continue to improve, the questions of risks versus benefits of long-term bone-modifying agents and how to mitigate atypical femoral fracture risk become increasingly pertinent.

Evolution of diagnostic workup and treatment for multiple myeloma 2013-2019

OBJECTIVE

To evaluate changes in diagnostic and therapeutic approach in multiple myeloma among Norwegian hematologists in the current decade.

METHODS

This nationwide study in Norway is based on results of surveys conducted among professionally active hematologists from 2013 to 2019. Every year, respondents participating in the survey suggested treatment regimens used in typical clinical situations in patients with multiple myeloma, as well as diagnostic routines.

RESULTS

The use of regimens containing alkylators and thalidomide was common at the beginning of the studied period. Later, lenalidomide became the most preferred treatment in most first-line patients. Bortezomib maintained a stable position in the treatment of myeloma in patients with renal insufficiency. The lenalidomide, bortezomib, and dexamethasone combination became the preferred frontline triplet for transplant-ineligible patients and induction therapy before transplant. Nowadays, the relapse after lenalidomide-based treatment is managed using both bortezomib-based therapies and combinations with the newest agents. Together with the therapeutic landscape, the use of diagnostic criteria and workup as well as supportive care changed in the period influenced by local and international guidelines and recommendations.

CONCLUSION

Norwegian hematologists gradually adopt new clinical concepts, guidelines, and recommendations in their practice.

Special considerations for the treatment of multiple myeloma according to advanced age, comorbidities, frailty and organ dysfunction

Multiple Myeloma (MM) is primarily a disease of old age with a median age of sixty-nine years at diagnosis. The development of novel therapies for induction and use of autologous stem cell transplantation has resulted in improved clinical outcomes and better quality of life for MM patients. Elderly patients, comprising the majority of MM population, have a higher incidence of age-related comorbidities, frailty and organ dysfunction which complicates the coordination of treatment and limits the selection of therapies. Even in the era of multiple chemotherapeutic options, the clinical heterogeneity of the myeloma patients' demands personalized treatments which often require dose-adjustments or dose delays. The use of reduced-dose regimens and various comorbidity indices has improved clinical outcome and regimen tolerability in MM patients with renal, neurological and bone abnormalities. We focus on advancements in the treatment of multiple myeloma with the goal to guide clinicians towards patient-specific management.

Bisphosphonate guidelines for treatment and prevention of myeloma bone disease

Multiple myeloma (MM) is a haematological malignancy characterised by the clonal proliferation of plasma cells in the bone marrow. More than 80% of patients with MM display evidence of myeloma bone disease (MBD), characterised by the formation of osteolytic lesions throughout the axial and appendicular skeleton. MBD significantly increases the risk of skeletal-related events such as pathologic fracture, spinal cord compression and hypercalcaemia. MBD is the result of MM plasma cells-mediated activation of osteoclast activity and suppression of osteoblast activity. Bisphosphonates (BP), pyrophosphate analogues with high bone affinity, are the only pharmacological agents currently recommended for the treatment and prevention of MBD and remain the standard of care. Pamidronate and zoledronic acid are the most commonly used BP to treat MBD. Although generally safe, frequent high doses of BP are associated with adverse events such as renal toxicity and osteonecrosis of the jaw. As such, optimal duration and dosing of BP therapy is required in order to minimise BP-associated adverse events. The following guidelines provide currently available evidence for the adoption of a tailored approach when using BP for the management of MBD.

The Singapore Myeloma Study Group Consensus Guidelines for the management of patients with multiple myeloma

Multiple myeloma (MM) is an incurable plasma cell neoplasm with an incidence of 100 patients per year in Singapore. Major advances have been made in the diagnosis, risk stratification and treatment of MM in the recent past. The reclassification of a subset of patients with smouldering MM, based on high-risk biomarkers, and the development of the revised international staging system are among the key new developments in diagnosis and staging. The use of novel agent-based treatment has resulted in significant improvements in the survival and quality of life of many patients with MM. Determining the optimal use of proteasome inhibitors, immunomodulators and, more recently, monoclonal antibodies is an area of ongoing investigation. In this guideline, we aim to provide an overview of the management of MM, incorporating the latest developments in diagnosis and treatment.

Long-term safety of monthly zoledronic acid therapy beyond 1 year in patients with advanced cancer involving bone (LoTESS): A multicentre prospective phase 4 study

Malignant bone disease can cause significant morbidity. Monthly zoledronic acid (ZOL) reduces skeletal complications; however, limited data are available regarding long‐term safety. We aimed to assess efficacy and safety of ZOL beyond 1 year of treatment. We prospectively evaluated 73 patients; breast cancer (n = 29), castrate‐resistant prostate cancer (n = 13), multiple myeloma (n = 31) from 2006 to 2008 in 19 cancer centres. All patients were diagnosed with bone disease and had completed 1–2 years of monthly ZOL (4 mg) and received a further 1–2 years of therapy following contemporary guidelines for managing risks of osteonecrosis of the jaw (ONJ) and renal toxicity. Overall rates of skeletal‐related events (SREs), renal impairment and ONJ were assessed. Over the additional 1 year of treatment, only 5.5% (n = 4) of patients developed a new SRE. The overall Kaplan–Meier estimate for SRE incidence after 48 weeks on study was 6.75% (95 CI: 2.5–17.3). Although 51% of patients reported serious adverse events, only two cases were suspected as ZOL related. No patients had confirmed ONJ. The observed incidence of new renal impairment was 11% (none due to ZOL). Our study confirms the benefit over risk of continuing monthly ZOL for at least 2 years in patients with advanced cancer involving bone.

Bisphosphonate-Induced Osteonecrosis of the Jaw

Objective:

To review the risk of osteonecrosis of the jaw associated with bisphosphonates.

Data Sources:

A MEDLINE search (1966–January 2007) and a search of international Pharmaceutical Abstracts (1970–January 2007) were conducted to identify relevant literature. Additional references were reviewed from selected articles.

Study Selection and Data Extraction:

Articles related to bisphosphonate-induced osteonecrosis of the jaw were reviewed and summarized. Inclusion criteria required that articles be either case studies or case series that were reporting actual cases linking osteonecrosis of the jaw with bisphosphonate use. Articles that addressed sites of osteonecrosis not involving the jaw, teaching cases (fictitious patients), and a retrospective claims analysis paper were excluded from consideration.

Data Synthesis:

Bisphosphonates have recently been linked to osteonecrosis of the jaw, with the greatest incidence seen with the intravenous preparations zoledronic acid and pamidronate. Osteonecrosis refers to death of a part of the bone, resulting in decreased bone density. Although the majority of occurrences have been associated with the intravenous bisphosphonates, oral bisphosphonates have also been implicated. Other risk factors noted from reported cases include dental extraction or trauma to the jaw exposing part of the bone. It is difficult to determine an exact incidence of osteonecrosis of the jaw in the general population of patients prescribed bisphosphonates; however, the incidence in cancer patients is approximately 6–7%.

Conclusions:

Although discontinuation of intravenous bisphosphonates in cancer patients has been recommended, stopping oral bisphosphonates prior to dental work cannot be universally endorsed at this time, since it is unknown whether this is effective in reducing the risk of osteonecrosis of the jaw. Treatment of this condition is not well established; therefore, efforts should be directed toward prevention. Pharmacists may further counsel patients to practice good oral hygiene and regularly follow up with their dentist during therapy. Current evidence suggests limited surgical debridement with systemic and local antibiotics as treatments.

Osteonecrosis of the Jaws (ONJ) after Bisphosphonate Treatment in Patients with Multiple Myeloma: Decreasing ONJ Incidence after Adoption of Preventive Measures

Bisphosphonates (BPs) are administered to Multiple Myeloma (MM) patients with bone lytic lesion. Osteonecrosis of the Jaw (ONJ) is a complication reported since 2003 in patients treated with intravenous (IV) BPs such as zoledronic acid and pamidronate, with 6%–26.3% frequency in early literature series, before some preventive measures were recommended. We evaluated the occurrence of ONJ with and without dental preventive measures in MM patients treated with BPs in our centre between 1996 and 2015. Since 2005, MM patients (already under treatment or before treatment) underwent a baseline mouth assessment (dental visit, Rx orthopantomography, and eventual tooth avulsion or dental care if necessary) and were followed by a multidisciplinary team. We reviewed the charts of 119 MM patients receiving IV BPs, classified into 3 groups: (a) “historic group” (21 patients who had started BP treatment in years before the awareness of ONJ); (b) “screening group” (20 patients starting BPs without baseline evaluation); and (c) “prevention group” (78 patients starting therapy only after baseline preventive assessment and eventual dental care measures). ONJ was observed in 3/21 patients (14.2%) from group a, in 2/20 patients (10%) from group b, and in no patients from group c (0%). Notably, the median number of IV BP administrations decreased after 2005. Our data confirmed a meaningful reduction of ONJ risk in MM patients treated with BPs if preventive measures are applied. Both implementation of prevention measures and reduction of cumulative doses of IV BPs could have contributed to a decreased incidence of ONJ.

Osteonecrosis of the Jaws and Bisphosphonate Therapy

Bisphosphonates are a class of agents used to treat osteoporosis and malignant bone metastases. The efficacy of these agents in treating and preventing the significant skeletal complications associated with these conditions has had a major positive impact for patients and is responsible for their widespread use in medicine. Despite these benefits, osteonecrosis of the jaws has recently emerged as a significant complication in a subset of patients receiving these drugs. Based on a growing number of case reports and institutional reviews, bisphosphonate therapy may cause exposed and necrotic bone that is isolated to the jaw. This complication usually presents following simple dento-alveolar surgery, and can cause a significant adverse effect on the quality of life for most patients. The pathogenesis for this complication appears to be related to the profound inhibition of osteoclast function and bone remodeling.

Zoledronate induces autophagic cell death in human umbilical vein endothelial cells via Beclin-1 dependent pathway activation

Zoledronate has been reported to exhibit pro-apoptotic and anti-angiogenic effects in endothelial cells, which partially contributes to bisphosphonate-associated osteonecrosis of the jaw (BP-ONJ). Zoledronate can also induce autophagic cell death. The present study hypothesized that Zoledronate may activate autophagy to exert pro-apoptotic effects in endothelial cells and aimed to investigate the effect of Zoledronate on human umbilical vein endothelial cells (HUVECs) and explore the underlying mechanisms. The current study demonstrated that Zoledronate induced autophagy in HUVECs in a dose-dependent manner, as demonstrated by increased levels of microtubule-associated proteins 1A/1B light chain 3B-II (LC3B-II) and Beclin-1, and decreased levels of sequestome 1 (SQSTM1). In addition, treatment with chloroquine further increased LC3B-II and increased SQSTM1 levels, indicating that Zoledronate induces autophagy by increasing autophagic activity. Flow cytometry and Hoechst 33258 staining revealed that inhibition of autophagy with 3-methyladenine markedly attenuated Zoledronate-induced apoptosis. Furthermore, genetic knockdown of Beclin-1 significantly inhibited autophagy and apoptosis induced by Zoledronate. The present study therefore demonstrated that Zoledronate may promote Beclin-1-mediated autophagy to induce endothelial cell apoptosis, and suggests that blocking autophagy may represent a novel approach for the prevention of BP-ONJ in patients receiving Zoledronate.

Current Controversies in the Management of Myeloma Bone Disease

Recent significant advances in the treatment of multiple myeloma have resulted in an improvement in median overall survival from 4.6 years, for patients diagnosed between 2001 and 2005, to 6.1 years, for those diagnosed between 2006 and 2010 (Kumar et al., 2014). However, myeloma bone lesions persist in the absence of active disease and continue to be frequent and significant causes of patient morbidity and contribute to mortality. While bisphosphonate therapy in combination with anti-myeloma therapy remains the cornerstone of skeletal disease management in myeloma, open questions regarding the optimal management of patients with myeloma bone disease remain. This article will address when to initiate and stop bone-targeted therapy in patients with monoclonal gammopathies, duration of bisphosphonate treatment in the era of more effective anti-myeloma treatment, the role of bone resorption markers in determining the dosing schedule for anti-resorptive therapy, risks and benefits of long term anti-resorptive therapy, and whether anti-resorptive therapies should be stopped to enhance the potential anabolic effects of proteasome antagonists and other anabolic agents. J. Cell. Physiol. 231: 2374-2379, 2016. © 2016 Wiley Periodicals, Inc.

Bone Disease in Myeloma: The Claws of CRAB

A dynamic approach to use bisphosphonates according to biomarkers of bone metabolism is presented in the Z-MARK study by Raje and colleagues. This is a major step forward toward a rational approach to bisphosphonate usage.

Frequency of skeletal-related events and associated healthcare resource use and costs in US patients with multiple myeloma

OBJECTIVE

A potential complication for all new multiple myeloma (MM) patients is the clinical presentation of osteolytic lesions which increase the risk for skeletal-related events (SREs). However, the contribution of SREs to the overall economic impact of MM is unclear. The impact of SREs on healthcare resource utilization (HCRU) and costs for US patients with MM was analyzed in Truven Health Marketscan Commercial Claims and Medicare Supplemental Databases.

METHODS

Adults diagnosed with MM between January 1, 2005 and December 31, 2010 with ≥2 claims ≥30 days apart (first claim = index date) were included. SREs included: hypercalcemia, pathologic fracture, surgery for the prevention and treatment of pathologic fractures or spinal cord compression, and radiation for bone pain. Rates of HCRU (outpatient [OP], inpatient [IP], emergency room [ER], orthopedic consultation [OC], and ancillary) and healthcare costs were compared between MM patients with and without SREs. Inverse propensity weighting was applied to adjust for potential bias.

RESULTS

Of 1028 MM patients (mean age = 67, standard deviation = 13.2), 596 patients with ≥1 SRE and 432 without SREs were assessed. HCRU rates in IP, ER, and ancillary (p < 0.01) and mean total costs of OP, IP, and ER were significantly higher (p < 0.05) for patients with vs without SREs during follow-up. HCRU rates also increased with SRE frequency (p < 0.05 in OP, IP, ER, OC, and ancillary), as did mean total healthcare costs, except for OC (p < 0.001).

LIMITATIONS

A broad assessment of pharmacotherapy for the treatment of MM was not an objective of the current study. Bisphosphonate use was evaluated; however, results were descriptively focused on frequency of utilization only and were not included in the broader cost and HCRU analysis.

CONCLUSIONS

Among US patients with MM, higher SRE frequency was associated with a significant trend of higher HCRU and total healthcare costs in several settings.

Multiple myeloma

Multiple myeloma is a malignant disease characterised by proliferation of clonal plasma cells in the bone marrow and typically accompanied by the secretion of monoclonal immunoglobulins that are detectable in the serum or urine. Increased understanding of the microenvironmental interactions between malignant plasma cells and the bone marrow niche, and their role in disease progression and acquisition of therapy resistance, has helped the development of novel therapeutic drugs for use in combination with cytostatic therapy. Together with autologous stem cell transplantation and advances in supportive care, the use of novel drugs such as proteasome inhibitors and immunomodulatory drugs has increased response rates and survival substantially in the past several years. Present clinical research focuses on the balance between treatment efficacy and quality of life, the optimum sequencing of treatment options, the question of long-term remission and potential cure by multimodal treatment, the pre-emptive treatment of high-risk smouldering myeloma, and the role of maintenance. Upcoming results of ongoing clinical trials, together with a pipeline of promising new treatments, raise the hope for continuous improvements in the prognosis of patients with myeloma in the future.

The role of bisphosphonates in medical oncology and their association with jaw bone necrosis

Bisphosphonates, synthetic analogues to inorganic pyrophosphates found in the bone matrix, inhibit bone resorption. Bisphosphonates and their related effects on the jaw have been established since 2001. The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is multifactorial and still under investigation. Currently, drugs with mechanisms of action involving remodeling suppression, osteoclast depression, and decreasing angiogenesis are under investigation for causing BRONJ-like symptoms. Further studies are needed to determine the effective length of use of biphosponates and the efficacy of drug holidays to prevent BRONJ.

unveiling skeletal fragility in patients diagnosed with MGUS: no longer a condition of undetermined significance?

Monoclonal gammopathy of undetermined significance (MGUS) is a common finding in clinical practice, affecting greater than 3% of adults aged 50 years and older. As originally described, the term MGUS reflected the inherent clinical uncertainty of distinguishing patients with a benign stable monoclonal plasma cell disorder from subjects destined to progress to malignancy. There is now clear epidemiologic evidence, however, that patients with MGUS suffer from a significantly increased fracture risk and that the prevalence of MGUS is increased in patients with osteoporosis. Despite this relationship, no clinical care guidelines exist for the routine evaluation or treatment of the skeletal health of patients with MGUS. Recent work has demonstrated that circulating levels of at least two cytokines (CCL3/MIP-1α and DKK1) with well-recognized roles in bone disease in the related monoclonal gammopathy multiple myeloma are also increased in patients with MGUS. Further, recent imaging studies using high-resolution peripheral quantitative CT have documented that patients with MGUS have substantial skeletal microarchitectural deterioration and deficits in biomechanical bone strength that likely underlie the increased skeletal fragility in these patients. Accordingly, this Perspective provides evidence that the "undetermined significance" portion of the MGUS acronym may be best replaced in favor of the term "monoclonal gammopathy of skeletal significance" (MGSS) in order to more accurately reflect the enhanced skeletal risks inherent in this condition.

State of oral mucosa as an additional symptom in the course of primary amyloidosis and multiple myeloma disease

Multiple myeloma (myeloma multiplex (MM)) is a malignant non-Hodgkin's lymphoma derived from B cell. Its essence is a malignant clone of plasma cells synthesizing growth of monoclonal immunoglobulin, which infiltrate the bone marrow, destroy the bone structure, and prevent the proper production of blood cells components. The paper presents a case of 62-year-old patient who developed symptoms in addition to neurological and haematological changes in the oral mucosa in the course of multiple myeloma. The treatment resulted in partial improvement. The authors wish to draw attention not only to nonspecificity and rarity of changes in the mouth which can meet the dentist but also to the complexity of the multidisciplinary therapy patients diagnosed with MM.

Bone health in cancer patients: ESMO Clinical Practice Guidelines

There are three distinct areas of cancer management that make bone health in cancer patients of increasing clinical importance. First, bone metastases are common in many solid tumours, notably those arising from the breast, prostate and lung, as well as multiple myeloma, and may cause major morbidity including fractures, severe pain, nerve compression and hypercalcaemia. Through optimum multidisciplinary management of patients with bone metastases, including the use of bone-targeted treatments such as potent bisphosphonates or denosumab, it has been possible to transform the course of advanced cancer for many patients resulting in a major reduction in skeletal complications, reduced bone pain and improved quality of life. Secondly, many of the treatments we use to treat cancer patients have effects on reproductive hormones, which are critical for the maintenance of normal bone remodelling. This endocrine disturbance results in accelerated bone loss and an increased risk of osteoporosis and fractures that can have a significant negative impact on the lives of the rapidly expanding number of long-term cancer survivors. Finally, the bone marrow micro-environment is also intimately involved in the metastatic processes required for cancer dissemination, and there are emerging data showing that, at least in some clinical situations, the use of bone-targeted treatments can reduce metastasis to bone and has potential impact on patient survival.

Osteonecrosis of the jaw and renal safety in patients with newly diagnosed multiple myeloma: Medical Research Council Myeloma IX Study results

Bisphosphonates are recommended in patients with osteolytic lesions secondary to multiple myeloma. We report on the safety of bisphosphonate therapy with long-term follow-up in the Medical Research Council Myeloma IX study. Patients with newly diagnosed multiple myeloma were randomised to zoledronic acid (ZOL; 4 mg intravenously every 21-28 d) or clodronate (CLO; 1600 mg/d orally) plus chemotherapy. Among 1960 patients (5.9-year median follow-up), both bisphosphonates were well tolerated. Acute renal failure events were similar between groups (ZOL 5.2% vs. CLO 5.8% at 2 years; incidence plateaued thereafter). The overall incidence of confirmed osteonecrosis of the jaw (ONJ) was low, but higher with ZOL (ZOL 3.7% vs. CLO 0.5%; P < 0.0001). ONJ events were generally low grade and most occurred between 8 and 30 months (median time to ONJ, 23.7 months). Among 10 patients with ONJ recovery data, four patients in the ZOL group completely recovered, two patients improved, and three patients experienced no improvement; one CLO patient experienced no improvement. Dental surgery or trauma preceded ONJ in six ZOL patients. The incidence of renal adverse events was similar for ZOL and CLO. ONJ incidence remained low and was lower with CLO compared to ZOL. We have seen no further ONJ cases to date.

International Myeloma Working Group consensus statement for the management, treatment, and supportive care of patients with myeloma not eligible for standard autologous stem-cell transplantation

PURPOSE

To provide an update on recent advances in the management of patients with multiple myeloma who are not eligible for autologous stem-cell transplantation.

METHODS

A comprehensive review of the literature on diagnostic criteria is provided, and treatment options and management of adverse events are summarized.

RESULTS

Patients with symptomatic disease and organ damage (ie, hypercalcemia, renal failure, anemia, or bone lesions) require immediate treatment. The International Staging System and chromosomal abnormalities identify high- and standard-risk patients. Proteasome inhibitors, immunomodulatory drugs, corticosteroids, and alkylating agents are the most active agents. The presence of concomitant diseases, frailty, or disability should be assessed and, if present, treated with reduced-dose approaches. Bone disease, renal damage, hematologic toxicities, infections, thromboembolism, and peripheral neuropathy are the most frequent disabling events requiring prompt and active supportive care.

CONCLUSION

These recommendations will help clinicians ensure the most appropriate care for patients with myeloma in everyday clinical practice.

Cancer-associated bone disease

Bone is commonly affected in cancer. Cancer-induced bone disease results from the primary disease, or from therapies against the primary condition, causing bone fragility. Bone-modifying agents, such as bisphosphonates and denosumab, are efficacious in preventing and delaying cancer-related bone disease. With evidence-based care pathways, guidelines assist physicians in clinical decision-making. Of the 57 million deaths in 2008 worldwide, almost two thirds were due to non-communicable diseases, led by cardiovascular diseases and cancers. Bone is a commonly affected organ in cancer, and although the incidence of metastatic bone disease is not well defined, it is estimated that around half of patients who die from cancer in the USA each year have bone involvement. Furthermore, cancer-induced bone disease can result from the primary disease itself, either due to circulating bone resorbing substances or metastatic bone disease, such as commonly occurs with breast, lung and prostate cancer, or from therapies administered to treat the primary condition thus causing bone loss and fractures. Treatment-induced osteoporosis may occur in the setting of glucocorticoid therapy or oestrogen deprivation therapy, chemotherapy-induced ovarian failure and androgen deprivation therapy. Tumour skeletal-related events include pathologic fractures, spinal cord compression, surgery and radiotherapy to bone and may or may not include hypercalcaemia of malignancy while skeletal complication refers to pain and other symptoms. Some evidence demonstrates the efficacy of various interventions including bone-modifying agents, such as bisphosphonates and denosumab, in preventing or delaying cancer-related bone disease. The latter includes treatment of patients with metastatic skeletal lesions in general, adjuvant treatment of breast and prostate cancer in particular, and the prevention of cancer-associated bone disease. This has led to the development of guidelines by several societies and working groups to assist physicians in clinical decision making, providing them with evidence-based care pathways to prevent skeletal-related events and bone loss. The goal of this paper is to put forth an IOF position paper addressing bone diseases and cancer and summarizing the position papers of other organizations.

Long-term treatment with intravenous bisphosphonates in metastatic breast cancer: a retrospective study

Bisphosphonates are important therapies used to reduce the risk of skeletal-related events in patients with bone metastases from breast cancer (BC). This retrospective cohort study evaluated the incidence of osteonecrosis of the jaw (ONJ) and renal impairment in women (n = 221) with bone metastases from BC treated with intravenous bisphosphonates from January 1999 to June 2008. In the long-term cohort, 159 patients received pamidronate (n = 9), zoledronic acid (n = 110), or both (n = 40) for ≥24 months. The comparator group consisted of patients treated with intravenous bisphosphonates for 12-23 months (n = 62). After 39 months' median follow-up, six of 159 patients developed ONJ (3.8%; median 38.5 treatment cycles and 44 months' exposure) in the long-term cohort. Of patients who developed ONJ, 50% resumed intravenous bisphosphonates after a 12-month treatment holiday. Renal impairment developed in 19 patients in the long-term cohort (11.9%; median 26 treatment cycles and 26 months' exposure). Of these 19 patients, 11 (57.9%) recovered baseline renal function and seven (36.7%) showed partial recovery. After modification of the intravenous bisphosphonate regimen, 17 of 19 patients (89.4%) resumed therapy. Of the 62 patients in the comparator cohort, one patient developed ONJ (1.6%) and six developed renal impairment (9.7%). Similar incidence rates of ONJ and renal impairment were observed for the long-term and comparator cohorts. Times to ONJ or renal impairment also were similar across intravenous bisphosphonate type. Long-term (≥24 months) intravenous bisphosphonate use in metastatic BC is well tolerated, with low incidences of ONJ and renal impairment.

International Myeloma Working Group recommendations for the treatment of multiple myeloma-related bone disease

PURPOSE

The aim of the International Myeloma Working Group was to develop practice recommendations for the management of multiple myeloma (MM) -related bone disease.

METHODOLOGY

An interdisciplinary panel of clinical experts on MM and myeloma bone disease developed recommendations based on published data through August 2012. Expert consensus was used to propose additional recommendations in situations where there were insufficient published data. Levels of evidence and grades of recommendations were assigned and approved by panel members.

RECOMMENDATIONS

Bisphosphonates (BPs) should be considered in all patients with MM receiving first-line antimyeloma therapy, regardless of presence of osteolytic bone lesions on conventional radiography. However, it is unknown if BPs offer any advantage in patients with no bone disease assessed by magnetic resonance imaging or positron emission tomography/computed tomography. Intravenous (IV) zoledronic acid (ZOL) or pamidronate (PAM) is recommended for preventing skeletal-related events in patients with MM. ZOL is preferred over oral clodronate in newly diagnosed patients with MM because of its potential antimyeloma effects and survival benefits. BPs should be administered every 3 to 4 weeks IV during initial therapy. ZOL or PAM should be continued in patients with active disease and should be resumed after disease relapse, if discontinued in patients achieving complete or very good partial response. BPs are well tolerated, but preventive strategies must be instituted to avoid renal toxicity or osteonecrosis of the jaw. Kyphoplasty should be considered for symptomatic vertebral compression fractures. Low-dose radiation therapy can be used for palliation of uncontrolled pain, impending pathologic fracture, or spinal cord compression. Orthopedic consultation should be sought for long-bone fractures, spinal cord compression, and vertebral column instability.

How I treat patients with indolent and smoldering mastocytosis (rare conditions but difficult to manage)

Indolent systemic mastocytosis (SM) patients have a varied clinical presentation, ranging from predominantly cutaneous symptoms to recurrent systemic symptoms (eg, flushing, palpitations, dyspepsia, diarrhea, bone pain) that can be severe and potentially life threatening (anaphylaxis). Mastocytosis patients without skin involvement pose a diagnostic challenge; a high index of suspicion is needed in those with mast cell–degranulation symptoms, including anaphylaxis following Hymenoptera stings or other triggers. Modern-era molecular and flow-cytometric diagnostic methods are very sensitive and can detect minimal involvement of bone marrow with atypical/clonal mast cells; in some cases, full diagnostic criteria for SM are not fulfilled. An important aspect of treatment is avoidance of known symptom triggers; other treatment principles include a stepwise escalation of antimediator therapies and consideration of cytoreductive therapies for those with treatment-refractory symptoms. The perioperative management of mastocytosis patients is nontrivial; a multidisciplinary preoperative assessment, adequate premedications, and close intra- and postoperative monitoring are critical. Smoldering mastocytosis is a variant with high systemic mast cell burden. While its clinical course can be variable, there is greater potential need for cytoreductive therapies (eg, interferon-alpha, cladribine) in this setting. A systematic approach to the diagnosis and treatment of indolent SM using a case-based approach of representative clinical scenarios is presented here.

Renal Safety and Pharmacokinetics of Ibandronate in Multiple Myeloma Patients With or Without Impaired Renal Function

In this open-label study, the authors assessed the pharmacokinetics and safety of ibandronate in patients with multiple myeloma and varying renal function. Renal deterioration was graded at baseline depending on creatinine clearance in 4 stages (0: >80; 1: 50-79; 2: 30-49, and 3: <30 mL/min). Patients (n = 40) received intravenous ibandronate 6 mg (30-minute infusion). Ibandronate excretion and serum levels were measured over 24 hours. Serum creatinine, creatinine clearance, and markers of tubular damage were monitored before ibandronate infusion and at 24 and 72 hours following ibandronate infusion. Ibandronate clearance, AUC(0-24), AUC(0-infinity), serum t((1/2)), and C(max) were calculated. There was a significant positive correlation between ibandronate clearance and creatinine clearance (r = 0.858; P < .00001). The AUC for grade 3 renal insufficiency increased by approximately 60% versus grade 0 (P < .01) but was not significantly different between other grades of renal function. The t((1/2)) did not increase significantly, and peak serum levels of ibandronate were similar for the 4 grades of renal function. Serum creatinine, creatinine clearance, and markers of tubular damage did not change significantly within 72 hours of ibandronate infusion. Despite renal function already being compromised in this patient group, there was no evidence of acute nephrotoxicity with ibandronate.

Decreasing frequency of osteonecrosis of the jaw in cancer and myeloma patients treated with bisphosphonates: the experience of the oncology network of piedmont and aosta valley (north-Western Italy)

Background. Data concerning frequency of Osteonecrosis of Jaws (ONJ) are mostly based on single center experiences. Patients and Methods. Since 2005 a multidisciplinary study group collected data of cases of ONJ in patients treated with Bisphosphonates (BP) and observed in oncology and hematology centers of a regional network. Results. By December 2008, 221 cases were registered. We report details of 200 cases, identified after cross-checking reports from centres of medical oncology, haematology, and oral care. Primary neoplasm was breast cancer (39%), myeloma (32%), prostate cancer (16%), and other types of cancer (8%). In about 50% of the cases a history of dental extraction was present. Zoledronic acid was administered (alone or with other BP) to 178 patients (89%). Median time from first infusion to ONJ diagnosis was 21.0 (zoledronic acid only) and 39.0 months (pamidronate only). The number of ONJ cases per year was 3 in 2003, 21 in 2004, 58 in 2005, 60 in 2006, 37 in 2007, and 21 in 2008. Conclusion. The number of new ONJ cases in cancer and myeloma patients increased until 2006 and then reduced. The possible reasons of this trend (introduction of zoledronic acid; increase of ONJ awareness; diffusion of preventive dental measures; late modifications of BP prescription) are herein discussed.

Multiple myeloma: an update

Multiple myeloma is a rare, largely incurable malignant disease of plasma cells. Patients usually present with hypercalcemia, renal insufficiency, anemia and/or lytic bony lesions along with a monoclonal protein in the serum and/or urine in addition to an increase in the number of clonal plasma cells in the bone marrow. Patients with myeloma live on an average for five to seven years, with their survival dependent on the presence or absence of different prognostic markers. Treatment of younger fit patients is with induction therapy consisting of steroids with one or more novel anti-myeloma agents followed by high dose melphalan and autologous stem cell transplantation, while older and less fit patients are treated with melphalan-based combination chemotherapy. Supportive care is of paramount importance and includes the use of bisphosphonates, prophylactic antibiotics, thrombosis prophylaxis and the use of hematopoietic growth factors along with the treatment of complications of disease and its therapy. As more progress is being made and deeper responses are being attained, the disease might turn into a potentially curable one in the near future.

Absence of exposed bone following dental extraction in beagle dogs treated with 9 months of high-dose zoledronic acid combined with dexamethasone

PURPOSE

Factors contributing to osteonecrosis of the jaw with anti-remodeling drug treatment are unclear. Epidemiologic and experimental studies have suggested the combination of bisphosphonates and dexamethasone results in osteonecrosis of the jaw more often than either agent alone. The goal of this study was to assess the combination of these 2 drugs in a large animal model previously shown to be susceptible to exposed bone in the oral cavity when treated with bisphosphonates.

MATERIALS AND METHODS

Skeletally mature beagle dogs were untreated controls or treated with zoledronic acid (ZOL), dexamethasone (DEX), or ZOL plus DEX. ZOL and DEX were given at doses based on those used in humans. All animals underwent single molar extraction at 7 and 8 months after the start of the study. Extraction sites were obtained at month 9 for assessment of osseous healing using micro-computed tomography and histology.

RESULTS

No animals were observed to have exposed bone after dental extraction, yet 1 animal treated with ZOL and 1 treated with ZOL plus DEX had severely disrupted extraction sites as viewed by computed tomography and histology. These 2 animals had an intense periosteal reaction that was less obvious but still present in all ZOL-treated animals and absent from untreated animals. There was no significant difference in bone volume within the socket among groups at 4 or 8 weeks after healing, yet the ratio of surface to volume was significantly higher in animals treated with ZOL plus DEX at 8 weeks compared with control animals.

CONCLUSIONS

These findings suggest a more complex pathophysiology to osteonecrosis of the jaw than is implied by previous epidemiologic studies and those in rodents and raise questions about the potential role of DEX in its etiology.

Incidence and risk factors of bisphosphonate-related osteonecrosis of the jaw in multiple myeloma patients having undergone autologous stem cell transplantation

BACKGROUND

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe complication of bisphosphonate therapy. Due to their long survival and subsequently high cumulative doses of bisphosphonates, multiple myeloma patients have the highest risk of developing BRONJ of all patients treated with bisphosphonates. The purpose of the present study was to evaluate the incidence and risk factors for BRONJ in multiple myeloma patients after high-dose chemotherapy and autologous stem cell transplantation (ASCT).

PATIENTS AND METHODS

We retrospectively analyzed the data of 120 multiple myeloma patients after high-dose chemotherapy and ASCT treated with bisphosphonates and assessed the incidence and risk factors of BRONJ.

RESULTS

Of the 120 patients, 23 (19%) developed BRONJ. 6 patients suffered several BRONJ events, resulting in a total incidence of 23%. The risk for BRONJ was significantly higher for patients with rheumatism and recent dental manipulations. Furthermore, the number of previous bisphosphonate rotations, the duration of bisphosphonate therapy, and the type and cumulative dose of bisphosphonate used were associated with the incidence of BRONJ.

CONCLUSION

Our study is the first to determine the risk of BRONJ in a homogeneous group of multiple myeloma patients treated with high-dose chemotherapy and ASCT.

Zoledronate inhibits ischemia-induced neovascularization by impairing the mobilization and function of endothelial progenitor cells

Background

Bisphosphonates are a class of pharmacologic compounds that are commonly used to treat postmenopausal osteoporosis and malignant osteolytic processes. Studies have shown that bone marrow-derived endothelial progenitor cells (EPCs) play a significant role in postnatal neovascularization. Whether the nitrogen-containing bisphosphonate zoledronate inhibits ischemia-induced neovascularization by modulating EPC functions remains unclear.

Methodology/Principal Findings

Unilateral hindlimb ischemia was surgically induced in wild-type mice after 2 weeks of treatment with vehicle or zoledronate (low-dose: 30 μg/kg; high-dose: 100 μg/kg). Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio was significantly lower in wild-type mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in controls 4 weeks after ischemic surgery (control vs. low-dose vs. high-dose: 87±7% vs. *61±18% vs. **49±17%, *p<0.01, **p<0.005 compared to control). Capillary densities were also significantly lower in mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in control mice. Flow cytometry analysis showed impaired mobilization of EPC-like cells (Sca-1⁺/Flk-1⁺) after surgical induction of ischemia in mice treated with zoledronate but normal levels of mobilization in mice treated with vehicle. In addition, ischemic tissue from mice that received zoledronate treatment exhibited significantly lower levels of the active form of MMP-9, lower levels of VEGF, and lower levels of phosphorylated eNOS and phosphorylated Akt than ischemic tissue from mice that received vehicle. Results of the in vitro studies showed that incubation with zoledronate inhibited the viability, migration, and tube-forming capacities of EPC.

Conclusions/Significance

Zoledronate inhibited ischemia-induced neovascularization by impairing EPC mobilization and angiogenic functions. These findings suggest that administration of zoledronate should be withheld in patients with ischemic events such as acute limb ischemia.

Effects of induction and maintenance plus long-term bisphosphonates on bone disease in patients with multiple myeloma: the Medical Research Council Myeloma IX Trial

The Medical Research Council Myeloma IX Trial (ISRCTNG8454111) examined traditional and thalidomide-based induction and maintenance regimens and IV zoledronic acid (ZOL) and oral clodronate (CLO) in 1960 patients with newly diagnosed multiple myeloma. Overall survival (OS) and skeletal-related event (SRE) data have been reported for the overall trial population. The present analysis investigated optimal therapy regimens for different patient populations in Myeloma IX. Patients were assigned to intensive or nonintensive treatment pathways and randomized to induction cyclophosphamide, vincristine, doxorubicin, and dexamethasone (CVAD) versus cyclophosphamide, thalidomide, and dexamethasone (CTD; intensive) or melphalan and prednisolone versus attenuated oral CTD (CTDa; nonintensive). Patients were also randomized to ZOL or CLO. In the nonintensive pathway, CTDa produced better responses and lower SRE rates than melphalan and prednisolone. ZOL improved OS compared with CLO independently of sex, stage, or myeloma subtype, most profoundly in patients with baseline bone disease or other SREs. In patients treated for ≥ 2 years, ZOL improved OS compared with CLO from randomization (median not reached for either; P = .02) and also from first on-study disease progression (median, 34 months for ZOL vs 27 months for CLO; P = .03). Thalidomide-containing regimens had better efficacy than traditional regimens, and ZOL demonstrated greater benefits than CLO.

Persistency with zoledronic acid is associated with clinical benefit in patients with multiple myeloma

Zoledronic acid (ZOL), an intravenous bisphosphonate, has been shown to reduce and delay the incidence of skeletal-related events (SREs) in multiple myeloma (MM) patients with bone disease. A retrospective claims-based analysis was conducted that used two distinct US managed care databases to examine the relationship between persistency with ZOL and clinical benefit. Patients >18 years, diagnosed with MM, and with at least one claim for ZOL (or a claim for malignant bone disease and ZOL initiation within 30 days) between 1/1/2001 and 12/31/2006 were included. Patients were evaluated for incidence of SREs and for mortality. Treatment persistency was defined as the absence of a >45 day gap between ZOL administrations. Of 1,655 patients in this analysis, 1,060 received ZOL and 595 received no intravenous bisphosphonate therapy. Compared with patients not receiving bisphosphonate therapy, ZOL-treated patients had lower incidences of SREs (P < 0.0001) and death (P = 0.0001). Longer persistency with ZOL was associated with lower risks of SREs (P = 0.001), fracture (P = 0.003), and death (P = 0.002) versus shorter persistency. Patients who were persistent with ZOL for ≥1.5 years had an incidence of 15.0 SREs and 6.2 fractures per 100 person-years. Patients who were persistent for 31-90 days had an incidence of 24.6 SREs and 14.0 fractures per 100 person-years, and patients not receiving intravenous bisphosphonates had an incidence of 32.2 SREs and 16.9 fractures per 100 person-years. These data from a real-world setting indicate that among MM patients, longer persistency with ZOL was associated with a lower risk of SREs and fracture.

Bisphosphonate-related osteonecrosis of the jaws--a review

The aim was to evaluate the knowledge about bisphosphonate-related osteonecrosis of the jaws (BRONJ). A bibliographic search in Medline, PubMed and the Cochrane Register of controlled clinical trials was performed between 2003 and 2010 by using the terms bisphosphonate and osteonecrosis of the jaw. The amount of publications per year, the type of journal for publication, and the evidence level of the trial were evaluated. Next to this the incidences and the success of treatment strategies for BRONJ were identified. A total of 671 publications were reviewed. Since 2006 more than 100 publications on BRONJ per year (with an upward trend) have been published, mostly in dental journals. The evidence level could be determined for 176 publications and only one grade Ia study was found. The studies showed a wide variety in design, most of them being retrospective. The incidence of BRONJ is strongly dependent on oral or intravenous application and varies between 0.0% and 27.5%. There is no scientific data to sufficiently support any specific treatment protocol for the management of BRONJ. Further clinical studies are needed to evaluate the incidence and treatment strategies at a higher level of evidence. Therefore uniform study protocols would be favourable.