Absolute lymphocyte count trend and cytokine release syndrome incidence associate with teclistamab clinical outcomes. (A) Pretreatment absolute lymphocyte count for patients responding to teclistamab includes several patients with grade 3 or grade 4 lymphopenia. (B) ALC level changes during step-up dosing for teclistamab patients. (C) PFS with teclistamab stratified by patients with and without CRS during step-up dosing. (D) Response rates by IMWG classification for patients with and without CRS during step-up dosing. ALC, absolute lymphocyte count; IMWG, International Myeloma Working Group.