Treatment of multiple myeloma bone disease: experimental and clinical data

The core symptom in multiple myeloma patients undergoing chemotherapy: a network analysis

BACKGROUND

During chemotherapy for multiple myeloma, symptoms include those related to the disease, as well as adverse effects of the treatment. Few studies have explored the relationships between these symptoms. Network analysis could identify the core symptom in the symptom network.

OBJECTIVE

The aim of this study was to explore the core symptom in multiple myeloma patients undergoing chemotherapy.

METHODS

This was a cross-sectional study in which sequential sampling was used to recruit 177 participants from Hunan, China. Demographic and clinical characteristics were surveyed using a self-developed instrument. The symptoms of chemotherapy-treated multiple myeloma, including pain, fatigue, worry, nausea, and vomiting, were measured using a questionnaire with good reliability and validity. The mean ± SD, frequency, and percentages were used as descriptive statistics. Network analysis was used to estimate the correlation between symptoms.

RESULTS

The results showed that 70% of multiple myeloma patients using chemotherapy exhibited pain. In the network analysis, worrying was the dominant symptom, and the strongest relationship was between nausea and vomiting in chemotherapy-treated multiple myeloma patients' symptoms.

CONCLUSION

Worrying is the core symptom of multiple myeloma patients. Interventions could be most effective if there is a symptom management focus on worrying when providing care to chemotherapy-treated multiple myeloma patients. Nausea combined with vomiting could be better managed, which would decrease the cost of health care. Understanding the relationship between the symptoms of multiple myeloma patients undergoing chemotherapy is beneficial for precise symptom management.

IMPLICATIONS FOR PRACTICE

Nurses and health care teams should be a priority to intervene in the worrying for chemotherapy-treated multiple myeloma patients to maximize the effectiveness of an intervention. Except, nausea and vomiting should be managed together in a clinical setting.

Molecular mechanisms, current management and next generation therapy in myeloma bone disease

Multiple myeloma (MM) bone disease is a major cause of morbidity and mortality in MM patients and persists even in patients in remission. This bone disease is caused by an uncoupling of bone remodeling, with increased osteoclast and decreased osteoblast activity and formation, culminating in lytic bone destruction. Bisphosphonates are the current standard of care but new therapies are needed. As the molecular mechanisms controlling MM bone disease are increasingly well understood, new therapeutic targets are extensively explored in the preclinical setting and initial clinical trials with novel compounds now show promising results. In this review, we will provide a comprehensive overview of the biology of MM bone disease, summarize its current clinical management and discuss preclinical and clinical data on next generation therapies.

Genetic deletion of Sost or pharmacological inhibition of sclerostin prevent multiple myeloma-induced bone disease without affecting tumor growth

Multiple myeloma (MM) causes lytic bone lesions due to increased bone resorption and concomitant marked suppression of bone formation. Sclerostin (Scl) levels, an osteocyte-derived inhibitor of Wnt/β-catenin signaling, are elevated in MM patient sera and are increased in osteocytes in MM-bearing mice. We show here that genetic deletion of Sost, the gene encoding Scl, prevented MM-induced bone disease in an immune-deficient mouse model of early MM, and that administration of anti-Scl antibody (Scl-Ab) increased bone mass and decreases osteolysis in immune-competent mice with established MM. Sost/Scl inhibition increased osteoblast numbers, stimulated new bone formation and decreased osteoclast number in MM-colonized bone. Further, Sost/Scl inhibition did not affect tumor growth in vivo or anti-myeloma drug efficacy in vitro. These results identify the osteocyte as a major contributor to the deleterious effects of MM in bone and osteocyte-derived Scl as a promising target for the treatment of established MM-induced bone disease. Further, Scl did not interfere with efficacy of chemotherapy for MM suggesting that combined treatment with anti-myeloma drugs and Scl-Ab should effectively control MM growth and bone disease, providing new avenues to effectively control MM and bone disease in patients with active MM.

Bisphosphonate-Functionalized Imaging Agents, Anti-Tumor Agents and Nanocarriers for Treatment of Bone Cancer

Bone metastases result from the invasion of primary tumors to bone. Current treatment modalities include local treatments such as surgery and radiotherapy, while systemic treatments include chemotherapy and (palliative) treatment of skeletal metastases. Nevertheless, once bone metastases have been established they remain incurable leading to morbidity and mortality. Bisphosphonates are a well-established class of drugs, which are increasingly applied in the treatment of bone cancers owing to their effective inhibition of tumor cells and suppression of bone metastases. The increased understanding of the mechanism of action of bisphosphonates on bone and tumor cells has prompted the development of novel bisphosphonate-functionalized imaging and therapeutic agents. This review provides an update on the preclinical efficacy of bisphosphonate-functionalized fluorophore, anti-tumor agents and nanocarriers for the treatment of bone metastases. After an overview of the general characteristics of bisphosphonates and their mechanisms of action, an outline is provided on the various conjugation strategies that have become available to functionalize imaging agents, anti-tumor agents and nanocarriers with bisphosphonates. Finally, the efficacy of these bisphosphonate-modified agents and carriers in preclinical studies is evaluated by reviewing their potential to target tumors and inhibit tumor growth in clinically relevant animal models for the treatment of bone cancer.

The effects of proteasome inhibitors on bone remodeling in multiple myeloma

Bone disease is a characteristic feature of multiple myeloma, a malignant plasma cell dyscrasia. In patients with multiple myeloma, the normal process of bone remodeling is dysregulated by aberrant bone marrow plasma cells, resulting in increased bone resorption, prevention of new bone formation, and consequent bone destruction. The ubiquitin-proteasome system, which is hyperactive in patients with multiple myeloma, controls the catabolism of several proteins that regulate bone remodeling. Clinical studies have reported that treatment with the first-in-class proteasome inhibitor bortezomib reduces bone resorption and increases bone formation and bone mineral density in patients with multiple myeloma. Since the introduction of bortezomib in 2003, several next-generation proteasome inhibitors have also been used clinically, including carfilzomib, oprozomib, ixazomib, and delanzomib. This review summarizes the available preclinical and clinical evidence regarding the effect of proteasome inhibitors on bone remodeling in multiple myeloma.

Targeting the Bone Marrow Microenvironment

Unprecedented advances in multiple myeloma (MM) therapy during the last 15 years are predominantly based on our increasing understanding of the pathophysiologic role of the bone marrow (BM) microenvironment. Indeed, new treatment paradigms, which incorporate thalidomide, immunomodulatory drugs (IMiDs), and proteasome inhibitors, target the tumor cell as well as its BM microenvironment. Ongoing translational research aims to understand in more detail how disordered BM-niche functions contribute to MM pathogenesis and to identify additional derived targeting agents. One of the most exciting advances in the field of MM treatment is the emergence of immune therapies including elotuzumab, daratumumab, the immune checkpoint inhibitors, Bispecific T-cell engagers (BiTes), and Chimeric antigen receptor (CAR)-T cells. This chapter will review our knowledge on the pathophysiology of the BM microenvironment and discuss derived novel agents that hold promise to further improve outcome in MM.

Monoclonal antibodies - A new era in the treatment of multiple myeloma

Monoclonal antibodies (mAbs) are currently the most investigated therapeutic compounds in oncology, but there is no monoclonal antibody approved in the treatment of multiple myeloma (MM). Nevertheless several really promising molecules are under investigation in phase III clinical trials. Dominantly daratumumab (anti-CD38) and elotuzumab (anti-CS1) showed extraordinary effectiveness in phase I/II trials. The toxicity was acceptable which is important for their addition to standard anti-myeloma agents like proteasome inhibitors or immunomodulatory drugs. Monoclonal antibodies such as denosumab (anti-RANKL) or BHQ880 (anti-DKK-1) are investigated also in the management of myeloma bone disease. This review is focused on the most promising mAbs, their mechanisms of action and the rationale of use. Practically all available results have been described. If the ongoing trials confirm the efficacy and safety of mAbs, they would become an important part of MM treatment that would be translated in the further improvement of therapeutic outcomes.

Denosumab-related osteonecrosis of the jaw: a case report and management based on pharmacokinetics

Denosumab, a monoclonal antibody against the receptor activator for nuclear factor-kappa B ligand (RANKL), is a recently approved antiresorptive drug that suppresses osteoclast formation by targeting preosteclasts, in contrast to the traditional antiresorptive bisphosphonates that target mature osteoclasts. Osteonecrosis of the jaw (ONJ) is a well-known, if rare, side effect of bisphosphonate therapy; however, cases of ONJ have also been reported since 2010 in patients taking denosumab. We describe here a patient who developed ONJ while receiving denosumab; the pharmacokinetics of denosumab and bisphosphonates are discussed in the context of ONJ management.