Abstract
Cellular based therapies, such as bispecific T-cell engagers (TCE), have changed the landscape of myeloma treatment, but to the present day little is known about the use of these therapies in patients with prior allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this case report, we present a patient with multi-refractory multiple myeloma (MM), who relapsed after allo-HSCT and anti-SLAMF-7-CART-cell-therapy and was ultimately successfully treated with teclistamab, a BCMA-directed TCE, and we discuss theoretical considerations based on present literature about possible underlying immunological mechanisms, that might have contributed to a long enduring treatment response.