POS0693 EFFICACY AND SAFETY OF BELIMUMAB IN PATIENTS WITH LUPUS NEPHRITIS IN REAL-LIFE SETTING: RESULTS FROM A LARGE, NATIONWIDE, MULTICENTRIC, PROSPECTIVE COHORT
Authors: F. Saccon, M. Gatto, M. Zen, M. Fredi, F. Regola, F. Franceschini, A. Tincani, G. Emmi, F. Ceccarelli, F. Conti, A. Bortoluzzi, M. Govoni, M. Mosca, C. Tani, M. Gerosa, T. Ubiali, E. Bozzolo, G. A. Ramirez, L. Moroni, A. Gabrielli, P. Cardinaletti, E. Gremese, G. Tanti, S. De Vita, G. De Marchi, S. Fasano, F. Ciccia, G. Pazzola, C. Salvarani, G. Orsolini, M. Rossini, P. Faggioli, A. Laria, S. Scarpato, A. De Paulis, E. Brunetta, E. Bartoloni Bocci, R. Gerli, F. Benvenuti, L. Iaccarino, A. Doria
Journal: Annals of the Rheumatic Diseases (2021)

Background: LN is still a severe manifestation of Systemic lupus erythematosus (SLE) and multitarget therapy is needed to control the disease especially in refractory cases. Objectives: To evaluate renal response in SLE patients with glomerulonephritis (GN) treated with Belimumab in real-life setting. Methods: Patients with proteinuria &gt;0.5 g/24 h and/or active sediment at baseline enrolled in a multicentre Italian cohort of SLE patients (BeRLiSS study), treated with monthly iv Belimumab 10 mg/kg plus standard of care were considered in this study. Complete renal response (CRR ) was defined as proteinuria &lt;0.5 g/24 h, estimated glomerular filtration rate (eGFR)≥90ml/min/1.73m 2 and no rescue therapy. Primary efficacy renal response (PERR ) was defined as proteinuria ≤0.7 g/24 h, eGFR ≥60ml/min/1.73m 2 and no rescue therapy. Prevalence and predictive factors of CRR and PERR at 12 and 24 months after Belimumab initiation were analyzed by multivariate logistic regression analysis. Results: A total of 91 patients were considered in this study, 79 female, mean age 40.51±9.03 years, mean disease duration 12.18±8.15 years, median follow-up time after Belimumab initiation 22 months. Twenty patients had baseline proteinuria ≥0.5 &lt;1 g/day, 17 ≥1 &lt;2 g/day, 13 ≥2 g/day. Belimumab was started at GN onset in 20 (22%) patients and at the time of a renal flare in all other cases. Seventy-five patients underwent a renal biopsy: 1 class I, 4 class II, 14 class III, 47 class IV and 9 class V. Baseline serum creatinine was 82.44±29.26 umol/L; 15 patients showed eGFR&lt;60ml/min/1.73m 2 at baseline. Immunosuppresants were taken by 70 (76.9%) patients: 47 micofenolate, 15 azathioprine and 5 ciclosporine. Sixty patients (65.9%) were on antimalarials. During follow-up 34 (37.4%) patients achieved CRR. Among them 5 (14.7%) patients relapsed and 29 (85.3%) patients maintained remission. Mean time to achieved CRR was 9.71±5.91 months. High levels of baseline proteinuria were a negative independent predictor of CRR and PERR at 6 months (OR 0.044 CI95% 0.006-0.320 p=0.002 and OR 0.232 CI95% 0.091-0.596 p=0.002 ) and 12 months (OR 0.029 CI95% 0.002-0.556 p=0.019 and OR 0.056 CI95% 0.009-0.327 p=0.001 ). High levels of baseline creatinine were a negative independent predictor of renal response. Renal response at 6 months was a strong predictive factor of renal response at 12 and 24 months. Conclusion: Belimumab is an effective add-on therapy in the treatment of GN in real-life practice setting. Disclosure of Interests: None declared