CD138-directed adoptive immunotherapy of chimeric antigen receptor (CAR)-modified T cells for multiple myeloma

Abstract

Adoptive immunotherapy with T cells expressing a tumor-associated chimeric antigen receptor (CAR) provides a promising approach for tumor therapy. We designed a clinical trial for multiple myeloma (MM) treatment with CAR-modified T cells recognizing CD138 (CART-138). Five patients diagnosed with chemotherapy-refractory MM were enrolled into this trial, although one later advanced to plasma cell leukemia. By intravenous infusions, these patients received CD3⁺ CART-138 cells in an escalating dose. No intolerable toxicity was observed during this process. CART-138 cells were expanded to a level 1000 times higher than the initial engraftment level and were maintained in the peripheral blood. In addition, increased CART-138 cells were also detected in the bone marrow. Four of the five patients had stable disease (SD) longer than three months, and one patient with advanced plasma cell leukemia had a reduction of the myeloma cells in her peripheral blood (from 10.5% to <3%). This study suggests that the treatment of CART-138 is safe, feasible, and tolerable and has potential antitumor activity in vivo, warranting further research in MM treatment using CART-138.