RESUMEN
BackgroundBelimumab (BLM) is a monoclonal antibody that inhibits B-lymphocyte stimulating factor (BlyS) approved as a specific treatment for systemic lupus erythematosus (SLE) in 2011. We present the experience with BLM in a Spanish cohort with more than 460 patients.ObjectivesTo describe demographic characteristics, efficacy and safety of BLM in patients with SLE in Spanish population since its approval.MethodsDescriptive, retrospective, multicenter study in patients diagnosed with SLE according to EULAR/ACR 2019, SLICC and/or ACR 1997 diagnostic criteria. Data regarding SLE patients treated with BLM were collected from medical records (2011-2022). Demographic features, efficacy, laboratory variables, SLEDAI, renal involvement, steroid dose, administration routes and safety were assessed. To see whether a trend in BLM prescription had changed or not over time, two periods of time were analyzed: 2011-2016 (period1) and 2017-2022 (period2).ResultsBaseline characteristics of patients are summarized in Table 1.A total of 462 patients (36 hospitals) were included, 50.9% were on intravenous (IV), 34% on subcutaneous (SC) and 15.1% switched from IV to SC route. The median number of pre-BLM csDMARD use was 2.0 (2.0-3.0), being hydroxychloroquine (HCQ) the most frequently used (94.5%). Fifty-two patients were treated with IV cyclophosphamide with a median of 6 bolus received. At the time of BLM start, 443 patients were on prednisone with a median dose of 6.2 mg (5.0-10.0). Significant decreases in prednisone dose, SLEDAI and anti-DNA antibodies were observed from baseline until the last visit, whereas complement C3 and C4 values raised (Figure 1). A total of 118 patients (27.4%) had renal involvement with a median proteinuria of 1.0 g/day (0.5-2.4). Renal biopsy was done in 102 out of 118 patients, being class IV (33%), class III (21%) and class V (16%) the most frequently reported. After BLM, 73.3% of these patients improved (median proteinuria of 0.2 g/day (0.1-0.7).In period1, 100 patients started BLM compared to 362 in period2. The median time from SLE diagnosis to BLM begin was 7.1 (4.0-13.7) and 6.2 (2.1 -14.4) years in period1 and period2, respectively (p=0.454). We found a trend to use more csDMARD before BLM treatment in period1: 2.5 (2-3) vs. 2 (2-3) (p=0.088).A total of 143 (30.5%) patients discontinued treatment mostly due to inefficacy (55.9%) and infections (11.9%). In fact, 116 patients developed infections, mostly mild;2 patients died, 16 had COVID-19 and 4 patients developed tumors requiring discontinuation of the drug.ConclusionIn our cohort of SLE patients in a real-world setting, BLM has been effective, safe and seems to be a good choice to treat renal involvement.References[1]Navarra SV, Guzmán RM, Gallacher AE, et al. Lancet. 2011;377(9767):721-31.[2]Stohl W, Hiepe;rt al. Arthritis Rheum. 2012;64(7):2328-37.[3]Furie R, Rovin BH, Houssiau F, et al. N Engl J Med. 2020;383(12):1117-1128.Acknowledgements:NIL.Disclosure of InterestsNone Declared.