Effectiveness and Safety of Belimumab in Chinese Lupus Patients: A Multicenter, Real-World Observational Study.

: The effectiveness and safety of belimumab in Chinese lupus patients with different disease activities were investigated in a real-world setting. : Patients who received 10 mg/kg belimumab intravenously on weeks 0, 2, and 4, and then every 4 weeks on a background of standard-of-care (SoC) therapy and had a follow-up of more than 6 months were enrolled from four centers in China. They were stratified according to the Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) score at baseline as the moderate/severe (SELENA-SLEDAI > 6) or mild subgroups (SELENA-SLEDAI ≤ 6). Attainment of the Lupus Low Disease Activity State (LLDAS) or remission on treatment was analyzed in all patients. The SLE Responder Index 4 (SRI-4) and SELENA-SLEDAI Flare Index (SFI) were evaluated for patients with moderate/severe disease and mild disease, respectively. Patients in the control arm with SoC alone from previous metformin lupus trials were selected by propensity score matching (PSM) as the reference group. : 224 SLE patients with a mean follow-up of 11.7 months receiving belimumab were enrolled in this observational study, of which 126 and 98 were in the moderate/severe and mild subgroup, respectively. At 12 months, 54.76% of the patients attained LLDAS and 28.57% attained remission. Lower daily prednisone at baseline were independently associated with 12-month LLDAS. Further, 87% of the subgroup with moderate/severe disease achieved SRI-4 at 12 months and a high SLEDAI at baseline was its predictive factor. For the mild subgroup, a reduced flare rate was observed compared with PSM reference (17.5%, vs. 38.6%, = 0.021). Infection events, particularly viral infections and pneumonia were recorded in 7 and 6 patients, respectively. : Our real-world data supported the effectiveness and safety of belimumab in Chinese lupus patients.