Infectious complications following CAR-t cell therapy for B cell non-Hodgkin lymphoma: a single-center experience and review of the literature.

Chimeric antigen receptor T-cell (CAR-T) therapy targeting CD19 has significantly improved outcomes in the treatment of refractory or relapsed (R/R) B-cell non-Hodgkin lymphoma (NHL). Several risk factors including CAR-T cell-related toxicities and their treatments often lead to infectious complications (ICs); however, the pattern and timeline is not well established. We evaluated ICs in 48 patients with R/R B-cell NHL following CAR-T cell therapy at our institution. Overall, 15 patients experienced 22 infection events. Eight infections (4 bacterial, 3 viral and 1 fungal) occurred within the first 30 days and 14 infections (7 bacterial, 6 viral, 1 fungal) between days 31 to 180 following CAR-T infusion. Most infections were mild-to-moderate and fifteen infections involved the respiratory tract. Two patients developed mild-to-moderate COVID-19 infection and one patient a cytomegalovirus reactivation after CAR-T infusion. Two patients developed IFIs: one case each of fatal disseminated candidiasis and invasive pulmonary aspergillosis at day 16 and 77, respectively. Patients with more than 4 prior antitumor regimens and patient's ≥ 65 years had a higher infection rate. Infections in patients with relapsed/refractory B-cell NHL are common after CAR-T despite the use of infection prophylaxis. Age ≥ 65 years and having > 4 prior antitumor treatments were identified as risk factors for infection. Fungal infections carried significant impact in morbidity and mortality, suggesting a role for increase fungal surveillance and/or anti-mold prophylaxis following high-dose steroids and tocilizumab. Four of ten patients developed an antibody response following two doses of SARS-CoV-2 mRNA vaccine.