Long-term extended-interval teclistamab and talquetamab dosing without step-up dosing in previously treated multiple myeloma.

Teclistamab (Tec) and talquetamab (Tal) are bispecific CD3 T-cell engagers targeting B-cell maturation antigen and G protein-coupled receptor, class C, group 5, member D, respectively, and have transformed how we treat relapsed/refractory multiple myeloma (RRMM). Early onset toxicities, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), require utilization of pre-medications, step-up dosing (SUD) schemas, and close monitoring while late onset toxicities, such as hypogammaglobulinemia, myelosuppression, and notably infections, can lead to significant complications and treatment interruptions, which may require extending bispecific antibody (BsAb) dosing intervals to mitigate toxicities. While current prescribing information for Tec and Tal recommend repeat SUD for prolonged dose delays, we report a series of six patients (pts) who continued therapy with extended dosing intervals (EDI) (8-12 weeks) without repeating SUD. Notably, all pts had achieved a  ≥  complete response (CR) prior to transitioning to extended interval dosing, which was chosen either to improve tolerability or per provider preference based on depth of disease response. Despite experiencing CRS (83% of pts) and ICANS (17% of pts) during their initial SUD, no CRS or ICANS events occurred after 23 doses of Tec/Tal given at EDI, despite a median duration between doses of 77 days. At the time of this report, all patients in this cohort have sustained, deep disease response and remain on BsAb therapy. Despite small sample size, this report adds to limited available data supporting safe and feasible omission of SUD in RRMM pts slated for Tec/Tal therapy resumption via EDI.