Immunotherapy for Multiple Myeloma: A Report Outlining Currently Approved Monoclonal Antibody Treatments

Immunotherapy continues to be increasingly used for treating multiple myeloma (MM) with a recent report, published by Cancers, providing an overview of monoclonal antibodies (mAbs) currently approved for treating MM, as well as, compounds that are under investigation.

According to the study, mAbs target highly specific antigens on the cell surface of MM cells causing cell death, convey specific cytotoxic drugs, remove the breaks of the immune system, or boost it against myeloma cells.

Currently, 2 mAbs have been approved for treating MM, including the anti-CD38 daratumumab for newly diagnosed and relapsed/refractory patients and the anti-CS1 elotuzumab in the relapse setting. Researchers are evaluating these compounds in clinical trials to determine their synergy with other anti-MM methods.

“In the last 2 decades, the treatment armamentarium of effective anti-myeloma drugs, used both at diagnosis and at relapse, has been significantly expanded with various compounds of different drug-classes,” explained the authors. “However, despite the availability of several treatment options, MM still remains an incurable disease whose natural history is characterized by phases of disease remission followed by relapses. The remission duration tends to progressively decrease at every subsequent relapse and MM inevitably becomes refractory to all available agents.”

The researchers noted that B cell maturation antigens, selectively expressed on plasma cells, have emerged as a potential target that has generated several other developed compounds targeting it in the past. Specifically, the researchers reported that antibody drug conjugates and bispecific T cell engagers (BiTEs), including AMG420, have demonstrated encouraging results.

“The preliminary results obtained with single-agent [antibody-drug conjugates] or BiTEs^® in heavily pre-treated patients are by far exceeding expectations, especially if compared to the results obtained with the currently available single-agent drugs,” noted the authors. “Future studies will shed light on their role in the treatment of MM patients and on their efficacy when used earlier in the course of the disease; they will also explore how to improve their feasibility and treatment compliance, especially in relation to the continuous intravenous infusion characteristic of the BiTEs^® evaluated in MM thus far.”

The report suggested that a better understanding of the role immune system in the pathogenesis of MM is necessary as more research is conducted and treatment strategies are developed in the future.

Reference

Bonello F, Mina R, Boccadoro M, et al. Therapeutic Monoclonal Antibodies and Antibody Products: Current Practices and Development in Multiple Myeloma. [published online December 19, 2019]. Cancers. doi: https://doi.org/10.3390/cancers12010015.