BCMA directed Bispecific Antibody induced tumour flare in Multiple Myeloma

Bispecific antibodies have emerged as highly effective treatments for multiple myeloma patients even in late relapse when all available novel agents have been exhausted. However, they cause some adverse events of special interest (AESI) that treating physicians need to be aware of. AESIs like CRS and ICANS are reasonably wellcaptured and reported in most early phase and pivotal studies and their management strategies have been well discussed, debated, and published. However, tumour flare reactions caused by BsAb induced T-cell activation and associated inflammatory reaction have hardly been reported in the pivotal trials of their use in Myeloma. We would like to present a case to highlight this AESI (and discuss a management strategy) such that it can be promptly suspected and managed effectively.