Real-world outcomes of infections following tisagenlecleucel in patients with B-cell ALL: a CIBMTR analysis.

Tisagenlecleucel (tisa-cel) is a CD19-directed chimeric antigen receptor T-cell therapy for relapsed/refractory precursor B-cell acute lymphoblastic leukemia (R/R B-ALL). We report infectious complications for 100 days (D100) following tisa-cel therapy in 471 pediatric and young adults (median age 13.8 years) with R/R B-ALL reported from September 2017 to June 2022. By D100, 137 (29%) patients had an infectious event, with an infection density of 0.542 per 100 person-days at risk. D100 cumulative incidences of bacterial, viral, and fungal infections were 14.1%, 11.6%, and 1.3%, corresponding to infection density scores of 0.296, 0.213, and 0.033 per 100 person-days at risk, respectively. In a multivariable analysis, receipt of ≥3 lines of therapy before tisa-cel (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.13-3.08; P = .015), any-grade cytokine release syndrome (HR, 1.78; 95% CI, 1.17-2.71; P = .007), and lack of neutrophil recovery (HR, 2.63; 95% CI, 1.47-4.69; P = .001) were associated with an increased risk for any infection. Similar associations were observed for bacterial infections, with the addition of younger age as an adverse risk (<6 vs 6-15 years; HR, 2.38; 95% CI, 1.23-4.61; P = .01). Risk factors for viral infections included increasing age (1-year increase; HR, 1.05; 95% CI, 1.01-1.09; P = .016), prior history of any infection (HR, 2.76, 95% CI, 1.40-5.46; P = .004), and prior hematopoietic cell transplant (HR, 2.10; 95% CI, 1.18-3.71; P = .011). D100 infection-related mortality (IRM) rate was low at 0.2% (95% CI, 0.0-0.8). In this multicenter real-world study, we observed a high incidence of infectious complications but a low IRM following tisa-cel for R/R B-ALL.