Abstract
INTRODUCTION: Multiple Myeloma (MM) is currently an incurable disease, with constant relapses and the need for multiple lines of treatment. Immune therapies, which include bispecific antibodies such as elranatamab, are a new option for the treatment of patients with relapsed/refractory MM (R/R MM), with high effectiveness, but not free of adverse reactions. Tumor lysis syndrome (TLS) is a rare complication of MM treatment and has not been reported after application of elranatamab. CASE PRESENTATION: We report the case of a man with R/R MM who presented TLS after application of the first dose of elranatamab. The TLS resolved after supportive measures without subsequent recurrence. CONCLUSION: TLS is an uncommon complication of MM treatment and could be triggered by bispecific antibodies.