PO:12:318 Belimumab in monotherapy: a subanalysis of the Spanish national registry of belimumab in systemic lupus eythematosus

Objectives Background: Belimumab (BLM) is a monoclonal antibody that inhibits B-lymphocyte stimulating factor (BlyS), approved in 2011 as a treatment for systemic lupus erythematosus (SLE).We present the experience with BLM in monotherapy in this spanish cohort.Objectives To describe demographic characteristics, effectiveness and safety of BLM after biological disease-modifying antirheumatic drugs (bDMARD) since its approval in SLE and compare them with SLE patients without being treated with bDMARD.Methods Descriptive, retrospective, multicenter study in patients diagnosed with SLE according to EULAR/ACR 2019, SLICC and/or ACR 1997 diagnostic criteria treated with BLM after bDMARD.Data were collected from medical records of SLE patients treated with BLM since 2011.Results Ninety-seven patients received BLM after bDMARD.The main bDMARD use before BLM was rituximab in the 85.3% of patients.Baseline characteristics are summarized in table 1.Of the 97 patients with previous bDMARD treatment, 61.9%, 75.9%, 76.9% and 69.6% showed hematological, renal, joint and cutaneous improvement, respectively.A total of 42 patients (43.3%) discontinued treatment, of which 54.8% was due to ineffectiveness.BLM after bDMARD patients seemed to be a more difficult to treat patients since they started BLM later, had more antiphospholipid syndrome and used more cDMARD and cyclophosphamide.In overall bDMARD patients had a worse BLM survival comparing with those BLM patients used as the first bDMARD.No new safety serious adverse events related with BLM were reported. ConclusionsIn this registry BLM after bDMARD is effective but had a worse survival than BLM used as the first bDMARD in SLE patients.