Possible targets to treat myeloma-related osteoclastogenesis

ABSTRACT

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.

KEYWORDS:

• Bone disease
• inflammation
• multiple myeloma
• osteoclast
• RANKL
• therapeutic targets

Declaration of interest

N Giuliani has received honoraria from Amgen, Bristol Mayers Suibb, Celgene Italy, Millenium Pharmaceutical, and Janssen Pharmaceutical and research grants from Celgene Italy, and Janssen Pharmaceutical.  The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This work was supported by the ‘Associazione Italiana per la Ricerca sul Cancro’ under IG2017 Grant (id. 20299), the International Myeloma Foundation under 2018 Brian D. Novis Senior Research Grant, and the ‘Ministero della Salute’ under Ricerca finalizzata PE-2016 Grant (N Giuliani). M Bolzoni was supported by ‘Fondazione Italiana per la Ricerca sul Cancro’ fellowship (id. 18152).