The efficacy of rituximab plus belimumab or telitacicept in refractory lupus nephritis

Objective Lupus nephritis is a severe and common complication of systemic lupus erythematosus (SLE). The pathogenesis of lupus nephritis is characterized by B-cell activation and autoantibody formation. Rituximab and belimumab, as well as telitacicept, target B cells through different mechanisms, potentially exerting a synergistic effect in the treatment of lupus nephritis. This study aims to investigate the efficacy and safety of treatment with rituximab followed by belimumab or telitacicept in the management of refractory lupus nephritis.Methods We conducted a single-center, open-label, retrospective study, including 25 patients with refractory lupus nephritis. All patients received combination therapy with rituximab in individualized dosages to achieve peripheral B-cell depletion, and then followed by belimumab or telitacicept. The follow-up period was at least 12 months, and the primary end point was renal remission rate at the last follow-up.Results During a median follow-up of 19 (13, 29) months, 20 of 25 (80%) patients achieved objective remission (OR), including 19 (76%) patients achieved complete renal response (CRR). After rituximab (712 +/- 416mg in average), 18 patients received belimumab and seven patients received telitacicept. In the rituximab plus telitacicept group, all patients achieved CRR; while in the rituximab plus belimumab group, 12 (66.7%) patients achieved CRR and 13 (72.2%) patients achieved OR. The mean SLEDAI-2K score decreased from 15 +/- 6 to 6 +/- 6, representing an average reduction of 60%. At the last follow-up, 18/25 (72%) had prednisone <= 5 mg/d or even discontinued prednisone use. Adverse effects were mainly immunoglobulin deficiency, respiratory tract infection, urinary tract infections, and rash. No death occurred.Conclusions Rituximab followed by belimumab or telitacicept may be effective in inducing remission in refractory lupus nephritis, with tolerable adverse effects.