Long-Term Follow-Up of Bridging Therapies Prior to CAR T-Cell Therapy for Relapsed/Refractory Large B Cell Lymphoma

SIMPLE SUMMARY: Bridging therapy (BT) in the form of systemic therapy (ST), radiation therapy (RT), or combined-modality therapy (CMT) is increasingly being utilized prior to chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL). Prior institutional experiences with BT, and RT in particular, suggest it does not lead to increased toxicity or compromise outcomes. Further investigation of the optimal use of BT is warranted. In this research, we sought to evaluate the impact of BT in a large institutional cohort of patients who received commercial CAR T-cell therapy for LBCL, specifically examining the effect of BT modality and disease burden on outcomes. Here, we report the long-term outcomes of our CAR T cohort. The patients with limited disease treated with RT had favorable outcomes. Prospective studies are warranted to better characterize the optimal management of patients with relapsed/refractory LBCL who are planning to undergo CAR T-cell therapy to optimize treatment. ABSTRACT: Background: Bridging therapy (BT) with systemic therapy (ST), radiation therapy (RT), or combined-modality therapy (CMT) is increasingly being utilized prior to chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL). We report the long-term outcomes of the patients who received commercial CAR T-cell therapy with or without BT. Methods: The patients with LBCL who underwent infusion of a commercial CD19 CAR T product were eligible. The radiation was stratified as comprehensive or focal. The efficacy outcomes and toxicity were analyzed. Results: In total, 156 patients were included and, of them, 52.5% of the patients received BT. The median progression-free survival (PFS) was 0.65 years in the BT cohort compared to 1.45 years in the non-BT cohort. The median overall survival (OS) was 3.16 years in the BT cohort and was not reached in the non-BT cohort. The patients who received comprehensive radiation (versus focal) had significantly improved PFS and OS, achieving a 1-year PFS of 100% vs. 9.1% and 1-year OS of 100% vs. 45.5%. There was no difference in the severe toxicity between any of the nonbridging or BT cohorts. Conclusions: BT did not appear to compromise outcomes with respect to response rates, disease control, survival, and toxicity. The patients with limited disease treated with RT had favorable outcomes.