A single‑arm Phase 2 trial reported daratumumab, an anti‑CD38 monoclonal antibody, produced promising clinical and mechanistic signals in systemic lupus erythematosus (SLE), per a Nature Communications publication by Ostendorf, Zernicke, Klotsche and colleagues. The study evaluated efficacy endpoints and immune modulation in a refractory SLE cohort and observed meaningful activity in several patients. The data bolster interest in repurposing oncology antibodies for autoimmune indications and will inform design of randomized trials and safety monitoring plans. For immunology drug developers, the readout raises both opportunity (target validation) and caution (long‑term safety and patient selection).