First report of CART treatment in AL amyloidosis and relapsed/refractory multiple myeloma

Multiple myeloma (MM) remains incurable despite the number of novel therapies that have become available in recent years. Occasionally, a patient with MM will develop an amyloid light-chain (AL) amyloidosis with organ dysfunction. Chimeric antigen receptor T-cell (CART) therapy has become a promising approach in treating hematological malignancies. Our institution has developed a second-generation B-cell maturation antigen (BCMA)-CART which is currently being tested in a clinical trial for relapsed/refractory MM.We present the first reported case, to our knowledge, of a patient with AL amyloidosis and renal involvement in the course of an MM, successfully treated with CART therapy targeting BCMA. The patient received a fractioned dose of 3×10⁶/kg BCMA-CARTs after lymphodepletion. At 3 months from infusion, the patient had already obtained a deep hematological response with negative measurable residual disease by flow cytometry in the bone marrow. After 12 months, the patient remains in hematological stringent complete remission and has achieved an organ renal response with a decrease of 70% of proteinuria.This case suggests that concomitant AL amyloidosis in the setting of MM can benefit from CART therapy, even in patients in which predominant symptoms at the time of treating are caused by AL amyloidosis.