Caroline Houillier

The prognosis of relapsed primary central nervous system lymphoma (PCNSL) remains dismal. CAR T‐cells are a major contributor to systemic lymphomas, but their use in PCNSL is limited. From the LOC network database, we retrospectively selected PCNSL who had leukapheresis for CAR‐T cells from the third line of treatment, and, as controls, PCNSL treated with any treatment, at least in the third line and considered not eligible for ASCT. Twenty‐seven patients (median age: 68, median of three previous lines, including ASCT in 14/27) had leukapheresis, of whom 25 received CAR T‐cells (tisa‐cel: N = 16, axi‐cel: N = 9) between 2020 and 2023. All but one received a bridging therapy. The median follow‐up after leukapheresis was 20.8 months. The best response after CAR‐T cells was complete response in 16 patients (64%). One‐year progression‐free survival from leukapheresis was 43% with a plateau afterward. One‐year relapse‐free survival was 79% for patients in complete or partial response at CAR T‐cell infusion. The median overall survival was 21.2 months. Twenty‐three patients experienced a cytokine release syndrome and 17/25 patients (68%) a neurotoxicity (five grade ≥3). The efficacy endpoints were significantly better in the CAR T‐cell group than in the control group ( N = 247) (median PFS: 3 months; median OS: 4.7 months; p < 0.001). This series represents the largest cohort of PCNSL treated with CAR T‐cells reported worldwide. CAR T‐cells are effective in relapsed PCNSL, with a high rate of long‐term remission and a reassuring tolerance profile. The results seem clearly superior to those usually observed in this setting.