P06.11.B NEUROTOXICITY AND MANAGEMENT OF PRIMARY AND SECONDARY CNS LYMPHOMA AFTER ADOPTIVE IMMUNOTHERAPY WITH CD19-DIRECTED CAR T-CELLS

Abstract

Abstract BACKGROUND Chimeric antigen receptor (CAR) T-cells targeting CD19 have been established as a leading engineered T-cell therapy for systemic B-cell lymphomas; however, data for patients with CNS involvement are limited. Whether CAR T-cells represent a viable therapeutic avenue for such patients remains therefore unclear. MATERIAL AND METHODS We retrospectively searched our institutional database for patients with primary and secondary CNS lymphoma who were treated with CD19-directed CAR T-cells for active CNS disease. Clinical data, CNS-specific toxicities, imaging findings, and outcome were analyzed. RESULTS We identified 45 consecutive CAR T-cell transfusions for active CNS lymphoma at the Massachusetts General Hospital over a five-year period. This cohort includes 17 patients with primary CNS lymphoma (PCNSL; one patient with two CAR T-cell transfusions) and 27 patients with secondary CNS lymphoma (SCNSL). Mild neurotoxicity (grade 1-2) was observed after 19/45 transfusions (42.2%) and severe neurotoxicity (grade 3-4) after 7/45 transfusions (15.6%). A larger increase in C-reactive protein (CRP) levels and higher rates of neurotoxicity were detected in SCNSL. Early fever and baseline C-reactive protein levels predicted neurotoxicity occurrence. CNS response was seen in 31 cases (68.9%), including a complete response of CNS disease in 18 cases (40.0%) which lasted for a median of 11.4 ± 4.5 months. Dexamethasone dose at time of lymphodepletion (but not at or after CAR T-cell transfusion) was associated with an increased risk for CNS progression (HR per mg/d: 1.16, p = 0.031). If bridging therapy was warranted, the use of Ibrutinib translated into favourable CNS-progression free survival (5 versus 1 month, HR 0.28, CI 0.1-0.7; p = 0.010). CONCLUSION CD19-directed CAR T-cells exhibit promising anti-tumor effects and a favourable safety profile in patients with CNS lymphoma. Further evaluation on the role of bridging regimens and corticosteroids is urgently warranted.