[Refractory DLBCL to a polatuzumab-containing regimen: efficacy of CAR-T therapy in second line with radiotherapy bridging.]

DLBCL represents the prototype of aggressive lymphomas; despite therapeutic advances, a substantial proportion of patients remain refractory to first-line treatment. Anti-CD19 CAR-T therapy has revolutionized the second-line setting for patients with early relapse or refractory disease; however, real-world data in patients refractory to modern polatuzumab-containing regimens remain limited. We report the case of a 73-year-old woman with stage IVB GCB-type DLBCL, refractory to Pola-R-CHP and subsequently unresponsive to R-GEMOX. She was considered eligible for second-line axicabtagene ciloleucel. Due to rapid disease progression and worsening abdominal pain, palliative debulking radiotherapy to the abdominal mass was used as bridging therapy, achieving effective local control and clinical benefit. Following lymphodepleting conditioning, CAR-T infusion was well tolerated, with only grade 1 cytokine release syndrome and no ICANS. At 3 months post-infusion, PET imaging documented a complete metabolic response. This case supports the efficacy and feasibility of second-line CAR-T therapy even after failure of polatuzumab-based treatment and highlights radiotherapy as an effective and safe bridging strategy in patients with bulky or symptomatic disease.