The study evaluated the safety, tolerability and efficacy of allogeneic CD19 CAR NK-cell therapy in patients with relapsing or refractory systemic lupus erythematosus (SLE). Eighteen patients were enrolled who had previously received at least two standard systemic therapies, including biologics in 14 (78%) of them. Patients received a lymphodepleting regimen with fludarabine (25 mg/m² daily) and cyclophosphamide (300 mg/m² daily) from days -5 to -3, followed by three infusions of CAR NK cells in one cycle. Doses started at 0.75 × 10^9 CAR NK cells, with dose and schedule escalation. Cytokine release syndrome occurred in one (6%) patient (grade 1), neurotoxicity or other serious adverse events related to therapy were not observed, with no limiting toxicities. Of the nine patients with a follow-up longer than 12 months, six (67%) achieved DORIS-defined remission and low disease activity status (LLDAS). The therapy has shown excellent safety and achieved both rapid and long-lasting remission in patients with refractory SLE.[1][2]