Allogeneic transplantation after failure of chimeric antigen receptor‐T cells and exposure to bispecific antibodies: Feasibility, safety and survival outcomes

Summary Clinical outcome after chimeric antigen receptor (CAR)‐T‐cell failure in large B‐cell lymphoma (LBCL) is dismal. Allogeneic stem cell transplantation (alloSCT) represents a potentially curative salvage for relapsed/refractory LBCL, although concerns remain regarding its feasibility and safety in patients exposed to CAR‐T and bispecific antibodies. Between 2019 and 2025, 83 disease progressions were documented among 170 LBCL patients treated with CAR‐T in two academic centres; 69 (83%) started salvage treatment, the most frequent being glofitamab in 38 (55%); among those, we retrospectively analysed outcomes of 35 candidates for alloSCT consolidation. Ultimately, 13 (37%) underwent alloSCT after achieving complete (CR) or partial response. The median number of previous therapies was 5. All patients engrafted; grade III–IV acute graft‐versus‐host disease (GvHD) occurred in 8% and moderate‐to‐severe chronic GvHD in 15% of patients respectively. At 18.4‐month median follow‐up, non‐relapse mortality was 0%; all allografted patients are alive in CR; conversely, the outcome of 22 patients not proceeding to transplant was poor, with a median overall survival of 11.7 months and 13 disease‐related deaths (59%). Although in a small cohort of patients, our data highlight the potential benefit of alloSCT consolidation in selected responders to salvage regimens despite the extensive prior treatments with T‐cell redirecting therapies.