The Management of Relapsed and Refractory Multiple Myeloma.

The treatment of patients with relapsed and refractory multiple myeloma has become increasingly complex due to the rising number of available therapies. Patients are also increasingly exposed to, and refractory to, multiple classes of therapy at the time of progression. Patients who are at an early point in their myeloma disease course are likely to have several effective options, but choices and prognosis are limited for relapsing patients who are more heavily pretreated, particularly if they are at least triple-class refractory. When selecting the next line of therapy, it remains essential to consider patient comorbidities and frailty as well as treatment history and disease risk. Fortunately, the myeloma treatment landscape continues to evolve with the development of therapies directed toward new biologic targets, such as B-cell maturation antigen. These new agents, including bispecific T-cell engagers and chimeric antigen receptor T-cell therapy, have shown unprecedented efficacy in late-line myeloma and will be increasingly used at earlier time points. Novel combinations of currently approved treatments, including quadruplets and salvage transplantation, also remain important options for consideration.