Denosumab for the treatment of bone disease in solid tumors and multiple myeloma

Characteristics of isatuximab-derived interference in serum protein electrophoresis and immunofixation, and an absence of sustained in vivo interference due to belantamab mafodotin and denosumab

OBJECTIVES

Some therapeutic monoclonal antibodies, like daratumumab and elotuzumab, produce interfering monoclonal bands on serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Whether other common therapeutic antibodies also produce interference has not been systematically evaluated.

DESIGN AND METHODS

SPEP/IFE from patients receiving isatuximab (48 patients), belantamab mafodotin (BM; 41), and denosumab (41) were retrospectively reviewed for therapeutic antibody interference. Cases exhibiting isatuximab interference were quantified and the maximum duration of isatuximab effect was evaluated. To characterize band position, neat human serum was spiked with BM or denosumab at supratherapeutic concentrations. Band migration patterns were compared on SPEP and IFE, with band position expressed relative to other constant protein fractions.

RESULTS

Isatuximab-induced IFE interference was common (81.3 % of evaluated patients) with a maximum observed duration of 8 weeks. 10.4 % of isatuximab patients had IgG kappa monoclonal gammopathies that co-migrated with the drug; this subset could benefit from HYDRASHIFT 2/4 isatuximab testing. 8.3 % of IFE cases were negative for an isatuximab band but showed large, endogenous M-spikes migrating elsewhere. All patients in this group expired within 1 year of this finding. We hypothesize that an inability to detect isatuximab in this setting corresponds to a large residual myeloma burden that reduces isatuximab serum concentration. This observation may serve as a negative prognostic factor. Spiking studies demonstrated that BM and denosumab produce interference in vitro, but sustained interference was not observed in >40 treated patients.

CONCLUSIONS

Therapeutic antibody interference in patients receiving isatuximab is common, and can persist for at least 8 weeks after administration. >10 % of patients receiving isatuximab may benefit from HYDRASHIFT testing post-therapy. In contrast, BM and denosumab fail to produce sustained interference in treated patients.

Conditional knockout of PDK1 in osteoclasts suppressed osteoclastogenesis and ameliorated prostate cancer-induced osteolysis in murine model

BACKGROUND

The development and maintenance of normal bone tissue is maintained by balanced communication between osteoblasts and osteoclasts. The invasion of cancer cells disrupts this balance, leading to osteolysis. As the only bone resorbing cells in vivo, osteoclasts play important roles in cancer-induced osteolysis. However, the role of 3-phosphoinositide-dependent protein kinase-1 (PDK1) in osteoclast resorption remains unclear.

METHODS

In our study, we used a receptor activator of nuclear factor-kappa B (RANK) promoter-driven Cre-LoxP system to conditionally delete the PDK1 gene in osteoclasts in mice. We observed the effect of osteoclast-specific knockout of PDK1 on prostate cancer-induced osteolysis. Bone marrow-derived macrophage cells (BMMs) were extracted and induced to differentiate osteoclasts in vitro to explore the role of PDK1 in osteoclasts.

RESULTS

In this study, we found that PDK1 conditional knockout (cKO) mice exhibited smaller body sizes when compared to the wild-type (WT) mice. Moreover, deletion of PDK1 in osteoclasts ameliorated osteolysis and rPDK1educed bone resorption markers in the murine model of prostate cancer-induced osteolysis. In vivo, we discovered that osteoclast-specific knockout of suppressed RANKL-induced osteoclastogenesis, bone resorption function, and osteoclast-specific gene expression (Ctsk, TRAP, MMP-9, NFATc1). Western blot analyses of RANKL-induced signaling pathways showed that conditional knockout of PDK1 in osteoclasts inhibited the early nuclear factor κB (NF-κB) activation, which consequently suppressed the downstream induction of NFATc1.

CONCLUSION

These findings demonstrated that PDK1 performs an important role in osteoclastogenesis and prostate cancer-induced osteolysis by modulating the PDK1/AKT/NF-κB signaling pathway.

Therapeutic Monoclonal Antibody Interference in Monoclonal Gammopathy Monitoring: a Denosumab Experience

A 73-year-old woman was diagnosed with a lambda light chain myeloma. A follow-up immunofixation electrophoresis showed a monoclonal immunoglobulin (Ig)G kappa in addition to the regular lambda band. A monoclonal antibody therapy interference was suspected but her VRD (bortezomib, lenalidomide, dexamethasone) regimen did not include such a medication. Later it was learned that she was prescribed denosumab, a monoclonal human antibody agent to treat bone lesions. The IgG kappa band disappeared 7 months after the first and 4 months after the last dose of denosumab, confirming a case of interference. This case once again emphasizes the importance of delta check and close communication between clinicians to avoid a false result in electrophoresis. It also describes the migration pattern of denosumab. As therapeutic antibodies gain approval and enter into common clinical practice, drug interference will complicate electrophoresis testing in diagnosis and patient follow-up.

Biological and Clinical Aspects of Metastatic Spinal Tumors

Simple Summary

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Our literature review aimed to describe the up-to-date knowledge about the molecular pathways and biomarkers engaged in the spine’s metastatic processes. Moreover, we described current data regarding bone-targeted treatment, the emerging targeted therapies, radiotherapy, and immunotherapy used for the treatment of spine metastases. We hope that knowledge comprehensively presented in our review will contribute to the development of novel drugs targeting specific biomarkers and pathways. The more we learn about the molecular aspects of cancer metastasis, the easier it will be to look for treatment methods that will allow us to precisely kill tumor cells.

Abstract

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Thanks to continuous research, there appears more and more detailed knowledge about cancer and metastasis, but these transformations are extremely complicated, e.g., due to the complexity of reactions, the variety of places where they occur, or the participation of both tumor cells and host cells in these transitions. The right target points in tumor metastasis mechanisms are still being researched; that will help us in the proper diagnosis as well as in finding the right treatment. In this literature review, we described the current knowledge about the molecular pathways and biomarkers engaged in metastatic processes involving the spine. We also presented a current bone-targeted treatment for spine metastases and the emerging therapies targeting the discussed molecular mechanisms.

Bone Disease in Multiple Myeloma: Biologic and Clinical Implications

Multiple Myeloma (MM) is a hematologic malignancy characterized by the proliferation of monoclonal plasma cells localized within the bone marrow. Bone disease with associated osteolytic lesions is a hallmark of MM and develops in the majority of MM patients. Approximately half of patients with bone disease will experience skeletal-related events (SREs), such as spinal cord compression and pathologic fractures, which increase the risk of mortality by 20–40%. At the cellular level, bone disease results from a tumor-cell-driven imbalance between osteoclast bone resorption and osteoblast bone formation, thereby creating a favorable cellular environment for bone resorption. The use of osteoclast inhibitory therapies with bisphosphonates, such as zoledronic acid and the RANKL inhibitor denosumab, have been shown to delay and lower the risk of SREs, as well as the need for surgery or radiation therapy to treat severe bone complications. This review outlines our current understanding of the molecular underpinnings of bone disease, available therapeutic options, and highlights recent advances in the management of MM-related bone disease.

Management of Myeloma Bone Lesions

Multiple myeloma (MM) is a B-cell neoplasm characterized by clonal plasma-cell proliferation. The survival and prognosis of this condition have been significantly improved by treatment with active anti-MM drugs such as bortezomib or lenalidomide. Further, the discovery of novel agents has recently paved the way for new areas of investigation. However, MM, including myeloma-related bone diseases, remains fatal. Bone disease or bone destruction in MM is a consequence of skeletal involvement with bone pain, spinal cord compression, and bone fracture resulting from osteolytic lesions. These consequences affect disease outcomes, including patients' quality of life and survival. Several studies have sought to better understand MM bone disease (MBD) through the classification of its molecular mechanisms, including osteoclast activation and osteoblast inhibition. Bisphosphonates and the receptor activator of the nuclear factor-kappa B (NF-κB) ligand (RANKL) inhibitor, denosumab, prevent skeletal-related events in MM. In addition, several other bone-targeting agents, including bone-anabolic drugs, are currently used in preclinical and early clinical evaluations. This review summarizes the current knowledge of the pathogenesis of MBD and discusses novel agents that appear very promising and will soon enter clinical development.

An oligopeptide/aptamer-conjugated dendrimer-based nanocarrier for dual-targeting delivery to bone

Bone targeting is one of the most potentially valuable therapeutic methods for medically treating bone diseases, such as osteoarthritis, osteoporosis, nonunion bone defects, bone cancer, and myeloma-related bone disease, but its efficacy remains a challenge due to unfavorable bone biodistribution, off-target effects, and the lack of cell specificity. To address these problems, we synthesized a new dual-targeting nanocarrier for delivery to bone by covalently modifying the G4.0 PAMAM dendrimer with the C11 peptide and the CH6 aptamer (CH6-PAMAM-C11). The molecular structure was confirmed using ¹H-NMR and FT-IR spectroscopy. CLSM results showed that the novel nanocarrier could successfully accumulate in the targeted cells, mineralized areas and tissues. DLS and TEM demonstrated that CH6-PAMAM-C11 was approximately 40-50 nm in diameter. In vitro targeting experiments confirmed that the C11 ligand had a high affinity for HAP, while the CH6 aptamer had a high affinity for osteoblasts. The in vivo biodistribution analysis showed that CH6-PAMAM-C11 could rapidly accumulate in bone within 4 h and 12 h and then deliver drugs to sites of osteoblast activity. The components of CH6-PAMAM-C11 were well excreted via the kidneys. The accumulation of many more CH6-PAMAM-C11 dual-targeting nanocarriers than single-targeting nanocarriers was observed in the periosteal layer of the rat skull, along with aggregation at sites of osteoblast activity. All of these results indicate that CH6-PAMAM-C11 may be a promising nanocarrier for the delivery of drugs to bone, particularly for the treatment of osteoporosis, and our research strategy may serve as a reference for research in targeted drug, small molecule drug and nucleic acid delivery.

The metastasizing mechanisms of lung cancer: Recent advances and therapeutic challenges

Lung cancer is one of the common malignant tumors that threaten human life with serious incidence and high mortality. According to the histopathological characteristics, lung cancer is mainly divided into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for about 80-85% of lung cancers. In fact, lung cancer metastasis is a major cause of treatment failure in clinical patients. The underlying reason is that the mechanisms of lung cancer metastasis are still not fully understood. The metastasis of lung cancer cells is controlled by many factors, including the interaction of various components in the lung cancer microenvironment, epithelial-mesenchymal transition (EMT) transformation, and metastasis of cancer cells through blood vessels and lymphatics. The molecular relationships are even more intricate. Further study on the mechanisms of lung cancer metastasis and in search of effective therapeutic targets can bring more reference directions for clinical drug research and development. This paper focuses on the factors affecting lung cancer metastasis and connects with related molecular mechanisms of the lung cancer metastasis and mechanisms of lung cancer to specific organs, which mainly reviews the latest research progress of NSCLC metastasis. Besides, in this paper, experimental models of lung cancer and metastasis, mechanisms in SCLC transfer and the challenges about clinical management of lung cancer are also discussed. The review is intended to provide reference value for the future research in this field and promising treatment clues for clinical patients.

Survival in patients with carcinomas presenting with bone metastasis at diagnosis: a SEER population-based cohort study

INTRODUCTION

Carcinoma metastasis to bone is a common reason for consultation to orthopedic surgeons. The presence of bone metastases (BM) is usually associated with poor prognosis which is worsened in the presence of synchronous metastases. The purpose of this study was to: (1) identify the most common carcinomas presenting with BM at diagnosis, to (2) analyze their survival, and (3) compare this against the survival of patients with additional synchronous metastasis based on a large population analysis.

MATERIALS AND METHODS

Patients diagnosed with carcinoma between January 2010 and December 2015 were identified from the Surveillance, Epidemiology and End Results (SEER) database. The most common carcinomas presenting with BM at diagnosis were identified. Survival based on the presence of BM and synchronous metastases (lung, brain, liver, lymph nodes) was evaluated with Kaplan-Meier analysis. Five-year survival (%) stratified by carcinoma type was calculated. Hazard ratio (HR) for mortality comparing isolated BM to other synchronous metastases was performed.

RESULTS

A total of 4.85% of patients (98,606/2,035,204) with carcinoma presented with BM at diagnosis, most commonly from a lung primary. Five-year survival with isolated BM was lowest in patients with pancreatic carcinoma (5.8%, 95% CI 3.0-9.9%), and highest in patients with breast carcinoma (41.1%, 95% CI 38.6-43.5%). Synchronous metastases increased significantly the risk of mortality within the majority of carcinomas.

CONCLUSION

BM at diagnosis has a poor prognosis which is worsened if synchronous metastases are present; a fact to consider when planning orthopedic interventions.

LEVEL OF EVIDENCE

Level III, prognostic study.

Belantamab Mafodotin to Treat Multiple Myeloma: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple myeloma (MM) is a hematologic malignancy characterized by excessive clonal proliferation of plasma cells. The treatment of multiple myeloma presents a variety of unique challenges due to the complex molecular pathophysiology and incurable status of the disease at this time. Given that MM is the second most common blood cancer with a characteristic and unavoidable relapse/refractory state during the course of the disease, the development of new therapeutic modalities is crucial. Belantamab mafodotin (belamaf, GSK2857916) is a first-in-class therapeutic, indicated for patients who have previously attempted four other treatments, including an anti-CD38 monoclonal antibody, a proteosome inhibitor, and an immunomodulatory agent. In November 2017, the FDA designated belamaf as a breakthrough therapy for heavily pretreated patients with relapsed/refractory multiple myeloma. In August 2020, the FDA granted accelerated approval as a monotherapy for relapsed or treatment-refractory multiple myeloma. The drug was also approved in the EU for this indication in late August 2020. Of note, belamaf is associated with the following adverse events: decreased platelets, corneal disease, decreased or blurred vision, anemia, infusion-related reactions, pyrexia, and fetal risk, among others. Further studies are necessary to evaluate efficacy in comparison to other standard treatment modalities and as future drugs in this class are developed.

Various pathways of zoledronic acid against osteoclasts and bone cancer metastasis: a brief review

Zoledronic acid (ZA) is one of the most important and effective class of anti-resorptive drug available among bisphosphonate (BP), which could effectively reduce the risk of skeletal-related events, and lead to a treatment paradigm for patients with skeletal involvement from advanced cancers. However, the exact molecular mechanisms of its anticancer effects have only recently been identified. In this review, we elaborate the detail mechanisms of ZA through inhibiting osteoclasts and cancer cells, which include the inhibition of differentiation of osteoclasts via suppressing receptor activator of nuclear factor κB ligand (RANKL)/receptor activator of nuclear factor κB (RANK) pathway, non-canonical Wnt/Ca2+/calmodulin dependent protein kinase II (CaMKII) pathway, and preventing of macrophage differentiation into osteoclasts, in addition, induction of apoptosis of osteoclasts through inhibiting farnesyl pyrophosphate synthase (FPPS)-mediated mevalonate pathway, and activation of reactive oxygen species (ROS)-induced pathway. Furthermore, ZA also inhibits cancer cells proliferation, viability, motility, invasion and angiogenesis; induces cancer cell apoptosis; reverts chemoresistance and stimulates immune response; and acts in synergy with other anti-cancer drugs. In addition, some new ways for delivering ZA against cancer is introduced. We hope this review will provide more information in support of future studies of ZA in the treatment of cancers and bone cancer metastasis.

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.

Monoclonal antibodies in multiple myeloma

Treatment of multiple myeloma (MM) patients has radically changed over the last years following the introduction of next generation proteasome inhibitors (PI) and immunomodulatory derivative (IMiDs). In the last years, one further therapeutic option for MM patients is represented by monoclonal antibodies (MoAbs), that seem to change the paradigm of MM treatment, particularly for heavily pretreated or double refractory to a PI and IMiDs patients. Antibodies have an immune-based mechanism, induce durable responses with limited toxicity and combine well with existing therapies. The therapeutic effects are prevalently obtained by means of antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cell-mediated phagocytosis (ADCP), complement-dependent cytotoxicity (CDC) and concurrently by the induction of signals on cell effectors. Immunotherapeutic strategies offer a new and exciting approach to target key molecular pathways that continue to be implicated in the survival of malignant plasma cells. These targets include cell surface proteins (CD38, CD138 [SDC1], B cell maturation antigen [BCMA, TNFRSF17]), cytokines that play a role in plasma cell survival and proliferation (interleukin 6 [IL6] and B cell activating factor), signal regulators of bone metabolism (RANKL [TNFSF11], DKK1) and regulators of the immune system (PD-1[PDCD1], PD-L1[CD274]). This article focuses on new MoAbs and related innovative immunotherapeutic modalities currently under investigation in the treatment landscape of MM.

A Retrospective Observational Study of Risk Factors for Denosumab-Related Osteonecrosis of the Jaw in Patients with Bone Metastases from Solid Cancers

This single-center retrospective observational study aimed to identify risk factors for developing denosumab-related osteonecrosis of the jaw (DRONJ) in stage IV solid cancer patients with bone metastases. In total, 123 consecutive patients who had received 120 mg of denosumab every 4 weeks at least twice between July 2014 and October 2018 were included. We surveyed their demographics, medical history, blood test, underlying disease, and intraoral findings. Fourteen patients (11.4%) developed DRONJ within a mean denosumab administration period of 4 months (range: 2-52 months). Univariate analyses showed a statistically significant correlation between DRONJ and hormone therapy, chemotherapy/molecular target drug, apical periodontitis, periodontal disease, sex and body mass index. Multivariate analysis showed a statistically significant correlation between DRONJ and hormone therapy (odds ratio [OR], 22.07; 95% confidence interval [CI], 2.86-170.24), chemotherapy and/or molecular targeted therapy (OR, 18.61; 95% CI, 2.54-136.27), and apical periodontitis (OR, 22.75; 95% CI, 3.20-161.73). These findings imply that collaborative oral examinations by oral specialists may reduce the risk of development of DRONJ in patients treated with denosumab for bone metastases from solid cancers.

Bone complications in patients with multiple myeloma in five European countries: a retrospective patient chart review

BACKGROUND

Bone complications (pathologic fracture, spinal cord compression, surgery to bone and radiation to bone) are a common problem in patients with multiple myeloma (MM). We set out to provide insights into the real-world burden of bone complications in patients with newly diagnosed MM (NDMM).

METHODS

We conducted a retrospective review of medical charts of patients with NDMM whose disease had progressed following first-line treatment in the 3 months before data collection in 2016 in five European countries (France, Germany, Italy, Spain and the United Kingdom).

RESULTS

The aggregated study population included 813 patients. Bone pain commonly led to MM diagnosis (63%) and 74% of all patients had two or more bone lesions at initiation of first-line treatment. Furthermore, 26% of patients experienced a new bone complication between MM diagnosis and disease progression following first-line treatment, despite 75% of individuals receiving bisphosphonates. Most bone complications (52%) occurred in the period before initiation of first-line treatment (mean duration: 2.3 months) and more than half of patients (56%) who experienced a new bone complication were hospitalised. Analgesics were used more frequently in patients with bone complications than in those without them (76% vs 50%, respectively). Furthermore, 51% of patients had renal impairment by the time first-line treatment was started. Overall, 25% of patients did not receive bisphosphonates for prevention of bone complications and one in four of those with renal impairment at initiation of first-line treatment did not receive bisphosphonates.

CONCLUSIONS

Bone complications are common in patients with NDMM. They are frequently associated with hospitalization and analgesic use. Data from this study, conducted in the era of novel anti-myeloma therapies and before the approval of denosumab for use in patients with MM, suggest that although most patients (75%) received bisphosphonates, use of anti-resorptive therapy for prevention of bone complications may be suboptimal in patients with NDMM, irrespective of renal function.

Zoledronic Acid Improves Muscle Function in Healthy Mice Treated with Chemotherapy

Carboplatin is a chemotherapy drug used to treat solid tumors but also causes bone loss and muscle atrophy and weakness. Bone loss contributes to muscle weakness through bone-muscle crosstalk, which is prevented with the bisphosphonate zoledronic acid (ZA). We treated mice with carboplatin in the presence or absence of ZA to assess the impact of bone resorption on muscle. Carboplatin caused loss of body weight, muscle mass, and bone mass, and also led to muscle weakness as early as 7 days after treatment. Mice treated with carboplatin and ZA lost body weight and muscle mass but did not lose bone mass. In addition, muscle function in mice treated with ZA was similar to control animals. We also used the anti-TGFβ antibody (1D11) to prevent carboplatin-induced bone loss and showed similar results to ZA-treated mice. We found that atrogin-1 mRNA expression was increased in muscle from mice treated with carboplatin, which explained muscle atrophy. In mice treated with carboplatin for 1 or 3 days, we did not observe any bone or muscle loss, or muscle weakness. In addition, reduced caloric intake in the carboplatin treated mice did not cause loss of bone or muscle mass, or muscle weakness. Our results show that blocking carboplatin-induced bone resorption is sufficient to prevent skeletal muscle weakness and suggests another benefit to bone therapy beyond bone in patients receiving chemotherapy. © 2019 American Society for Bone and Mineral Research.

Risk factors for developing osteonecrosis of jaw in advanced cancer patients underwent zoledronic acid treatment

Aim: To investigate the risk factors for developing osteonecrosis of jaw (ONJ) in advanced cancer patients with bone metastases underwent zoledronic acid (ZA) treatment. Materials & methods: Univariate and multivariate logistic regression analyses were performed to investigate factors associated with developing ONJ in advanced cancer patients. Results: A total of 2214 advanced cancer patients were included. Univariate and multivariate logistic regression analyses for risk factors associated with ONJ were older age (≥66 years, hazards ratio [HR]: 3.21; p = 0.007), anemia (HR: 3.29; p = 0.006) and duration of ZA exposure (between 1 and 2 years, HR: 3.91, p = 0.01; ≥2 years, HR: 8.07, p < 0.001), respectively. Conclusion: Patients with older age, anemia and/or more than 1 year of ZA treatment are at high risk of developing ONJ.

The Contribution of the Immune System in Bone Metastasis Pathogenesis

Bone metastasis is associated with significant morbidity for cancer patients and results in a reduced quality of life. The bone marrow is a fertile soil containing a complex composition of immune cells that may actually provide an immune-privileged niche for disseminated tumor cells to colonize and proliferate. In this unique immune milieu, multiple immune cells including T cells, natural killer cells, macrophages, dendritic cells, myeloid-derived suppressor cells, and neutrophils are involved in the process of bone metastasis. In this review, we will discuss the crosstalk between immune cells in bone microenvironment and their involvement with cancer cell metastasis to the bone. Furthermore, we will highlight the anti-tumoral and pro-tumoral function of each immune cell type that contributes to bone metastasis. We will end with a discussion of current therapeutic strategies aimed at sensitizing immune cells.

Pharmacologic Modulation of Human Immunity in the Era of Immuno-oncology: Something Old, Something New

The concept of exploiting the immune system to treat cancer forms the basis of immuno-oncology. Since its birth in the late 1800s, immuno-oncology, or cancer immunotherapy, has come a long way. With better understanding of the complex relationship between tumor and the immune system, we have been able to explore and develop various modalities of anticancer therapies. In this review, we summarize the main strategies of immunotherapy that are available today: monoclonal antibodies, anticancer vaccines, cytokines, and adoptive T-cell therapy. We also highlight the unique set of adverse effects associated with modern immunotherapy and propose nonsteroidal immunomodulators and anticytokine antibodies as treatment options for toxicities. The future of immuno-oncology is discussed, including combination therapy, drug-antibody conjugates, epigenetic drugs, using nanoparticles for drug delivery, new antigen discovery, and developing biomarkers to assess treatment responses. A data search was conducted using PubMed and included studies published through November 1, 2017. Search terms used include cancer immunotherapy, pembrolizumab, ipilimumab, nivolumab, PD-1 inhibitors, PD-L1 inhibitors, checkpoint inhibitors, anticancer vaccines, TVEC, and adoptive cell therapy.

Possible targets to treat myeloma-related osteoclastogenesis

INTRODUCTION

Bone destruction is the hallmark of multiple myeloma (MM). About 80% of MM patients at diagnosis presents myeloma bone disease (MBD) leading to bone pain and pathological fractures, significantly affecting patients' quality of life. Bisphosphonates are the treatment of choice for MBD, but osteolytic lesions remain a critical issue in the current management of MM patients. Several studies clarified the mechanisms involved in MM-induced osteoclast formation and activation, leading to the identification of new possible targets and the development of better bone-directed therapies, that are discussed in this review. Areas covered: This review summarizes the latest advances in the knowledge of the pathophysiology of the osteoclast formation and activation induced by MM cells, and the new therapeutic targets identified. Recently, neutralizing antibodies (i.e. denosumab, siltuximab, daratumumab), as well as recombinant fusion proteins, and receptor molecular inhibitors, have been developed to block these targets. Clinical trials testing their anti-MBD potential are ongoing. The emerging role of exosomes and microRNAs in the regulation of osteoclast differentiation has been also discussed. Expert commentary: Although further studies are needed to arrive at a clinical approving, the basis for the development of better bone-directed therapies has been established.