Maintenance therapy after allogeneic hematopoietic stem cell transplantation for patients with multiple myeloma

Abstract

In the last two decades, proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and monoclonal antibodies have greatly improved the overall survival of patients with multiple myeloma. However, multiple myeloma remains incurable, and high-risk patients have poor long-term survival. Although allogeneic hematopoietic stem cell transplantation (allo-HCT) is not considered standard therapy because of relatively high transplant-related mortality and relapse rates, the graft-versusmyeloma (GVM) effect makes it a potentially curative therapy. Therefore, allo-HCT remains a treatment option for younger patients and those with high-risk myeloma. Maintenance therapy with novel agents has recently been attempted to reduce relapse in patients undergoing allo-HCT, but its effectiveness remains unclear. This review focuses on the role of maintenance therapy after allo-HCT in patients with myeloma. Maintenance therapy using IMiDs and/or PIs after allo-HCT may be effective in reducing relapse or improving response because it may prevent early progression before achievement of the GVM effect or enhance the GVM effect. However, care must be taken to avoid complications, such as graft-versus-host disease. Further studies are necessary to determine the optimal maintenance drugs, drug combinations, dosing, start timing, and number of cycles.

Immunotherapy of Multiple Myeloma: Current Status as Prologue to the Future

“…While at present this modality is generally reserved for young patients having high-risk relapsed myeloma, it remains controversial due to its overall mixed efficacy and lack of clear treatment guidelines [269]. On the other hand, this approach to MM therapy bears watching for future developments and possibly wider applications [270].…”