Pretreatment with Gpt, followed by sequential administration of glofitamab and CD19-CD28 mitigates cytokine release. (A) Non–tumor bearing humanized NSG mice (6 mice per group) were treated according to the depicted scheme, using the following doses: Gpt, 30 mg/kg; glofitamab, 0.15 mg/kg; CD19-CD28, 1 mg/kg. Histidine buffer was used as vehicle. Glofitamab and CD19-CD28 were either administered simultaneously (sim.) or sequentially (seq.), with a 3-day interval between treatments. Seq. and sim. combinations were either administered with or without Gpt 7 days before therapy. (B) Multiplex analysis of cytokines in serum at 4, 24, and 72 hours after last therapy injection. The absolute cytokine values are reported in supplemental Table 2. (C) Body weight kinetics. Dots show mean + SEM of body weight change of 6 mice per group. (D-I) Comparative analysis of T-cell activation and B-cell depletion in spleens, assessed via flow cytometry on study day 6. Bars show means, and dots indicate values of individual remaining mice at study termination. (J) Line plot shows mean fold change of plasma cytokine concentrations at indicated time points in patients with R/R NHL enrolled in the phase 1 clinical trial of glofitamab in combination with CD19-CD28 (NCT05219513). The error bars indicate SEM, and the dashed horizontal line indicates the baseline. The timing of each drug administration is shown by the dashed arrows. CxDx, cycle x day x.