Effect of continuously intravenously infused blinatumomab on cytokine release into sera of MRD⁺ ALL patients. Serum samples of assessable patients were analyzed for concentrations of IL-2, IL-4, IL-6, IL-10, IFN-γ, and TNF-α at the indicated time points. Mean values are shown for the (A) first and (B) second treatment cycle. IL-4 concentrations were below the limit of detection throughout all patients and are not depicted.