A Study Of Infections Of R/R B-ALL Patients After Treated With Sequential Infusion Of Anti-CD19 And Anti-CD22 CAR T-cells

Objective:A retrospective study was conducted on the infections of 90 patients with relapsed/refractory(R/R)acute B lymphoblastic leukemia(B-ALL)who were treated with sequential infusion of anti-CD19 and anti-CD22 CAR T-cells within 30 days before and 90 days after CAR T-cell therapy,in order to analyze the risk and risk factors of infections after CAR T-cell therapy,and to summarize the influencing factors of infection progression after CAR T-cell infusion in patients who had primary infections before CAR T-cell therapy.Methods:We analyzed 90 patients with R/R B-ALL who were treated with sequential infusion of anti-CD19 CAR T-cells and anti-CD22 CAR T-cells in Tongji Hospital affiliated to Huazhong University of Science and Technology from June 2016 to September 2019.The clinical data of these patients was collected,including past medical history,treatment history,baseline indicators before infusion,CAR T-cell treatment characteristics and infection-related data to analyze and summary the incidence,type of infections and risk factors of early infections after CAR T-cell therapy,and the risk factors of infection progression after CAR T-cell infusion in patients with primary infection before CAR T-cell therapy.Results:Overall,in the 56 patients without primary infections before CAR T-cell therapy,16 patients(28.6%)had 17 infections in the first 30 days after CAR T-cell infusion,most of which were bacterial infections and 2 patients(3.6%)died of infection.Receipt of bridging chemotherapy other than FC preconditioning chemotherapy were associated with an increased risk of infection.In the 34 patients with primary infections before CAR T treatment,11 patients’ infections progressed after CAR T-cell infusion(32.4%),and CRS grade 3 or higher was associated with an increased risk of infection progression.Conclusions:Infections were common in patients with R/R B-ALL after sequential infusion of anti-CD19 and anti-CD22 CAR T-cells,but life-threatening or fatal infections were rare.Understanding types and timing of infections and contributing risk factors can help inform prophylactic and monitoring strategies.Special attention should be paid to the patients with bridging chemotherapy.For patients with infections within 30 days before CAR T treatment,if severe CRS occurs after CAR T-cell therapy,it is necessary to guard against the possibility of primary infection progression.