Allogeneic transplant following CAR T-cell therapy for large B-cell lymphoma

Allogeneic hematopoietic cell transplantation (alloHCT) can potentially salvage large B-cell lymphoma (LBCL) patients ex-periencing treatment failure after chimeric antigen receptor T-cell therapy (CAR T). Nonetheless, data on the efficacy and toxicities of alloHCT after receipt of CAR T are limited. We report a multicenter retrospective study assessing the safety, toxicities, and outcomes of alloHCT in LBCL patients following CAR T failure. Eighty-eight patients with relapsed, refractory LBCL received an alloHCT following anti-CD19 CAR T failure. The median number of lines of therapy between CAR T infusion and alloHCT was one (range, 0-7). Low intensity conditioning was used in 77% (n=68) and peripheral blood was the most common graft source (86%, n=76). The most common donor types were matched unrelated donor (39%), followed by ha-ploidentical (30%) and matched related donor (26%). Median follow-up of survivors was 15 months (range, 1-72). One-year overall survival, progression-free survival, and graft -versus-host disease-free relapse-free survival were 59%, 45%, and 39% respectively. One-year non-relapse mortality and progression/relapse were 22% and 33% respectively. On multivariate analy-sis, <2 lines of intervening therapy between CAR T and alloHCT and complete response at time of alloHCT were associated with better outcomes. In conclusion, alloHCT after CAR T failure can provide durable remissions in a subset of patients.

Automated summary

Allogeneic hematopoietic cell transplantation (alloHCT) can be an effective treatment option for large B-cell lymphoma (LBCL) patients who have experienced treatment failure after chimeric antigen receptor T-cell therapy (CAR T). This study examined the safety, outcomes, and toxicities of alloHCT in LBCL patients following CAR T failure, and found that it can provide durable remissions in some patients. Factors such as fewer lines of intervening therapy and complete response at the time of alloHCT were associated with better outcomes.