Incidence and risk factors associated with a syndrome of persistent cytopenias after CAR-T cell therapy (PCTT)

Anti-CD19 Chimeric Antigen Receptor T cells (CAR-T) have shown dramatic efficacy in treating refractory aggressive B cell Lymphomas leading to FDA approval of axicabtagene ciloleucel and tisagenlecleucel. While long-term remission rate for both is higher than 33%, this treatment is associated with life-threatening complications including cytokine-release syndrome, encephalopathy, and lethal cerebral edema. Here we describe a case series of bone marrow failure syndromes with or without co-existing clonal myelodysplastic syndrome. Bone marrow failure was defined as absolute neutrophil count (ANC) <500 neutrophils/μL day 42 after infusion of CAR-T cells or filgrastim support to reach that number. We use "persistent cytopenias after T-cell therapy (PCTT)" to describe this syndrome which has an incidence of 38% with axicabtagene ciloleucel. Platelets <75,000/μL at the time of initiation of lymphodepleting chemotherapy and occurrence of maximum severity of cytokine-release syndrome (CRS) on day 0 or 1 after infusion of CAR-T cells are independent predictors of PCTT.