Strategy for Maintenance Therapy for Transplant-eligible and Non-eligible Patients with Multiple Myeloma

Abstract

Multiple myeloma (MM) is a hematological malignancy originating from plasma cells producing immunoglobulin. Introducing high-dose melphalan therapy followed by auto stem cell transplantation (ASCT) and novel drugs has improved the survival of patients with MM. The importance of maintenance therapy after induction therapy has been investigated to obtain a long duration of progression-free survival (PFS) after induction therapy. The role of maintenance therapy in MM is to inhibit disease progression after induction therapy without physical and financial burden for patients. Physical burden mainly refers to the side effects of treatment. Preventing relapse with minimum burden is beneficial. Here, we review the updated progress of maintenance therapy for transplant-eligible and -ineligible patients with MM. The results of clinical studies about maintenance therapies using thalidomide, lenalidomide, bortezomib, and ixazomib are demonstrated. The possible choice of treatment based on these results is suggested, and the utility of drug combination as a maintenance therapy is discussed. Furthermore, we describe the outline of the clinical trial we just commenced. We started an ixazomib maintenance therapy for transplant-ineligible patients intolerant to lenalidomide (IMTIL) study (UMIN000048285) to determine the efficacy and safety of ixazomib maintenance therapy in transplant-ineligible patients with MM who cannot be treated with standard doses of lenalidomide due to adverse reactions or frailty during or after induction therapy. In addition, the relationship between the efficacy of ixazomib in maintenance therapy and driver mutation and immune status is assessed.