Response to tocilizumab in 2 patients. Patient 1 is a 54-year-old male who received T cells transduced with a CAR targeting B-cell maturation antigen. He experienced CRS starting 4 hours following T-cell infusion, with development of fevers, tachycardia, tachypnea, hypoxia, and hypotension requiring vasopressors. (A) Patient 1 received tocilizumab 25 hours after his cell infusion, which was followed by a transient decrease in temperature and heart rate. He experienced worsening CRS and received a second dose of tocilizumab on day 5 following cell infusion, which was followed by a sustained decrease in temperature and heart rate. (B) The respiratory rate of patient 1 decreased following his first dose of tocilizumab, and intubation was avoided. (C) Patient 2 is a 20-year-old woman with a history of ALL with a past history of a matched-related donor SCT. She received donor-derived T cells transduced with a CAR targeting CD19 for progressive ALL after transplant. She experienced CRS toxicity with fevers, tachycardia, tachypnea, hypoxia, left ventricular systolic dysfunction, prolonged activated PTT, and increased creatine kinase. She received tocilizumab on day 4 following CAR T-cell infusion. Her respiratory rate decreased following tocilizumab, and intubation was avoided. (D) The heart rate of patient 2 decreased following tocilizumab. (E) Following tocilizumab, CRP in patient 2 decreased over a period of days. Professional illustration by Patrick Lane, ScEYEnce Studios.