XmAb5574-induced depletion is followed by B-cell recovery in blood and tissue. XmAb5574 was given as a single infusion at 10 mg/kg to 6 cynomolgus monkeys. B cells were measured in the blood throughout the study and in the bone marrow and lymph node tissues on days 15 and 85 (D15 and D85) by the method described in the Figure 2 legend. (A) Blood B-cell levels dropped rapidly before the onset of recovery, which was underway in all animals by day 57. (B) B-cell levels in the tissue were reduced at day 15 and were recovering at day 85. (C) Serum IgG remained unchanged throughout the study despite extensive B-cell depletion. Values shown are the mean (± SE) at each time point.