Successful generation of fully human, second generation, anti-CD19 CAR T cells for clinical use in patients with...

B-cell targeting chimeric antigen receptor (CAR) T-cell therapies, which lead to profound B-cell depletion, have been well-established in hematology-oncology. This deep B-cell depletion mechanism has prompted the exploration of their use in B-cell driven autoimmune diseases. We herein report on the manufacturing of KYV-101, a fully human anti-CD19 CAR T-cell therapy, derived from patients who were treated across a spectrum of autoimmune diseases.

KYV-101 was manufactured from peripheral blood-derived mononuclear cells of 20 patients across seven autoimmune disease types (neurological autoimmune diseases, n = 13; rheumatological autoimmune diseases, n = 7). Patients ranged from 18 to 75 years of age. Duration of disease ranged from <1 to 23 years since diagnosis. Patients were heavily pretreated, and most were refractory to prior immunosuppressive treatments. Apheresis was collected across nine sites, cryopreserved, and shipped to the manufacturing facility. Healthy donor apheresis samples were collected for manufacturing comparison. Manufacturing was performed using the CliniMACS Prodigy system. Cells were enriched for CD4⁺/CD8⁺ T cells, transduced with a third generation lentiviral vector encoding the CAR, expanded in vitro, and harvested. Percent cell viability, T-cell purity, cellular expansion, and transduction efficiency were assessed. Activity was assessed using cytokine release assays for KYV-101 CAR T cells co-cultured with different CD19^+/- target cell lines.

KYV-101 was successfully manufactured for 100% of patients. Transduced cell populations were highly viable, with expansion ranging from 11 to 66 fold at Day 8, and were comparable across disease types. Healthy donor-derived controls displayed similar expansion ranges. High CAR expression and transduction rates were observed, ranging between 37 and 77% with low variation in transgene copy number (two to four per cell). Cell viability of the final KYV-101 drug product ranged from 87 to 97%. KYV-101 displayed robust CD19-dependent and effector dose-related release of the pro-inflammatory cytokine IFN-γ.

KYV-101 manufacturing yielded a CAR T-cell product with high viability and consistent composition and functionality, regardless of disease indication, pre-treatment, and heterogeneity of the incoming material. Cryopreservation of the apheresis and final drug product enabled widespread distribution. These results support the robustness of the manufacturing process for the fully human KYV-101 anti-CD19 CAR T-cell therapy drug product for patients across diverse autoimmune disease types.