The management of patients with difficult-to-treat multiple myeloma

Lay abstract New treatments have extended the lives of many patients with multiple myeloma (MM). Still, MM can sometimes be difficult to control. In some patients, their MM will return after a period of months or years (known as relapse). In others, treatment will need to be stopped or changed due to side effects. Changes to the myeloma cancer cells can sometimes cause a treatment to stop working (known as resistance). Other groups of patients with MM who can be hard to treat are those with a more aggressive type of myeloma called extramedullary disease, and those who are old or frail or have other illnesses. This paper summarizes a meeting of expert doctors at the 25th European Hematology Association Annual Congress 2020. They discussed how to select the best treatment for patients with MM whose condition is difficult to control. They also discussed new medicines that are being tested for the treatment of MM. Newer treatments for multiple myeloma (MM) have improved response rates and survival for many patients. However, MM remains challenging to treat due to the propensity for multiple relapses, cumulative and emergent toxicities from prior therapies and increasing genomic complexity that arises due to clonal evolution. In particular, patients with relapsed/refractory MM often require increased complexity of treatment, yet still experience poorer outcomes compared with patients who are newly diagnosed. Additionally, several patient subgroups, including those with extramedullary disease and patients who are frail and/or have multiple comorbidities, have an unfavorable prognosis and remain undertreated. This review (based on an Updates-in-Hematology session at the 25th European Hematology Association Annual Congress 2020) discusses the management of these difficult-to-treat patients with MM.