Cytopenias and infections following ciltacabtagene autoleucel in heavily-pretreated relapsed or refractory multiple myeloma.

Ciltacabtagene autoleucel (cilta-cel) was FDA-approved in February 2022 for the treatment of relapsed/refractory multiple myeloma after 4 lines of therapy. On CARTITUDE-1 trial, grade ≥3 cytopenias and infections were common. Herein, we sought to characterize cytopenias and infections after cilta-cel infusion in the standard-of-care setting. This multicenter retrospective study included 105 patients who received cilta-cel; 91 reached day-90 and 49 reached day-180 follow-up. Grade ≥3 cytopenia was present among 52% of patients on day-30, and 24% of patients on day-90. Based on the newer immune effector cell-associated hematotoxicity (ICAHT) grading for neutropenia severity, 11 patients (10%) experienced grade ≥3 early ICAHT in the first 30 days, while only 3 (3.3%) experienced grade ≥3 late ICAHT after day-30. On univariate analysis, any grade thrombocytopenia at apheresis was associated with grade ≥3 cytopenia at both days 30 and 90. Granulocyte colony-stimulating factor was administered to 65%, transfusion support to 38%, thrombopoietin agonists to 10%, intravenous immunoglobulin to 52%, and CD34+ stem cell boosts to 9.5% of patients. Infections occurred in 49% of patients and were severe in 32%. Earlier infections in the first 30 days were equally bacterial (42%) and viral (42%). Later infections between days 31-100 and after day 100 were mostly viral (59% and 60%), with only 32% and 12% being grade ≥3 at each time period. On univariate analysis, worse ECOG performance status at lymphodepletion, higher maximum grade of CRS, delayed neurotoxicity, steroid and anakinra use, and lower IgA levels at day 90 were associated with severe infections.