Successful treatment of ultra-high-risk refractory multiple myeloma with anti-BCMA CAR-T therapy followed by allogeneic hematopoietic stem cell transplantation: a case report

Abstract

Recently, chimeric antigen receptor T cell (CAR-T) therapy targeting B cell maturation antigen (BCMA) has produced unprecedented and encouraging results in relapsed and/or refractory multiple myeloma (RRMM) after multiple lines of treatment, especially among high-risk patients; however, most patients inevitably relapse after CAR-T therapy. Exploring therapeutic strategies followed by CAR-T therapy has attracted increasing attention that warrants continued investigation. Herein, we present a young patient with RRMM and ultra-high-risk genetic abnormalities and refractoriness to a proteasome inhibitor (bortezomib), immunomodulatory drugs (lenalidomide and pomalidomide), a cytotoxic drug (liposomal doxorubicin), and anti-CD38 monoclonal antibody. After three lines of treatment, the patient underwent CAR-T therapy targeting BCMA for salvage treatment, then achieved a very good partial response with good tolerability. Subsequently, we performed an allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an HLA-matched unrelated donor as consolidation therapy. The efficacy was evaluated as a stringent complete response 42 days after the allo-HSCT. The patient has achieved progression-free survival for > 9 months after transplantation. The success of our case demonstrated that for carefully selected patients, anti-BCMA CAR-T therapy followed by allo-HSCT is effective and feasible in treating RRMM. A longer duration of follow-up and additional studies are needed to affirm this therapeutic strategy.