Optec/Optal: A phase 2 study to evaluate outpatient (OP), step-up administration of teclistamab (Tec) or talquetamab (Tal) with prophylactic tocilizumab (prophyToci) in patients (pts) with relapsed/refractory multiple myeloma (RRMM).

7510 Background: Tec, a B-cell maturation antigen x CD3 bispecific antibody (bsAb), and Tal, a G protein-coupled receptor class C group 5 member D x CD3 bsAb, are approved for the treatment of pts with triple-class exposed (TCE) RRMM. Cytokine release syndrome (CRS) is a common adverse event associated with T-cell therapies. CRS occurred in 72% and 73-79% of pts in the MajesTEC-1 (TEC-1) and MonumenTAL-1 (TAL-1) studies, respectively. One cohort of pts in TEC-1 received prophyToci, resulting in a lower rate of CRS (26%) without negatively impacting safety or efficacy. A cohort of pts in TAL-1 received prophyToci, with 18% experiencing CRS; safety and efficacy were comparable to the overall TAL-1 population. Methods: This nonrandomized, multicenter, prospective study evaluates prophyToci in RRMM pts treated with Tec (Arm A) or Tal (Arm B) using the approved step-up dose (SUD) schedule in the OP setting. ProphyToci 8 mg/kg was administered before SUD 1 of either Tec or Tal. Specific recommendations (home monitoring, IV immunoglobulin [IVIG] for IgG levels