POS0697 SAFETY OF BELIMUMAB IN ADULT PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A LARGE INTEGRATED SAFETY ANALYSIS OF CONTROLLED CLINICAL TRIAL DATA

Background: Belimumab (BEL), a monoclonal antibody that antagonizes B-lymphocyte stimulator, was first approved in 2011 for active, autoantibody-positive systemic lupus erythematosus (SLE). BEL has been studied over 10 years; and while safety data from individual trials have informative, large integrated analysis not yet conducted. Objectives: Perform pooled analyses to evaluate the of adult patients with SLE. Methods: Aggregate were performed using ≥18 years age six randomised, placebo (PBO)-controlled clinical (GSK studies: LBSL02, 110752, 110751, 112341, 113750, 115471). Patients GSK studies 110751 received intravenous (IV) 1, 4 (LBSL02 only), or mg/kg, PBO on Days 14, 28, every 28 days thereafter. 113750 115471 IV mg/kg study 112341 subcutaneous (SC) 200 mg, weekly. Safety included incidence adverse events (AEs), serious AEs (SAEs), severe AEs, special interest (AESI), mortality (all doses formulations combined) vs at Week 52. Results: The 4170 patients. Overall, 81.0% (n=2280/2815) receiving 76.6% (n=1038/1355) completed their respectively enrolled study; most common reason withdrawal occurrence an AE both groups. majority female (BEL: 94.5%; PBO: 93.6%), mean groups 38 years, baseline characteristics (race, SLE duration, disease activity, damage, complement levels, anti-dsDNA binding, medication usage) similar between treatments. experiencing ≥1 AE, SAE, across treatments (Table 1); commonly reported SAEs infections infestations 5.4% [n=151/2815]; 5.9% [n=80/1355]). duration treatment exposure 334.1 days; 325.3 days). A greater proportion experienced AESI post-infusion/injection reactions (from SC administration) depression/suicide/self-injury 1). malignancies Conclusion: Consistent studies, demonstrated profile this trials. These results support positive benefit–risk Funding: Table 1. Pooled N (% ) (IV + N=1355 N=2815 1184 (87.4) 2440 (86.7) SAE 230 (17.0) 421 (15.0) Severe (severe life threatening 209 (15.4) 377 (13.4) resulting drug discontinuation 109 (8.0) 184 (6.5) Death 6 (0.4) 16 (0.6) Post-infusion/injection reactions* 110 (8.1) 286 (10.2) Serious 2 (0.1) 13 (0.5) All (OIs, HZ, TB, sepsis) 97 (7.2) 173 (6.1) 17 (1.3) 40 (1.4) OIs 92 (6.8) 157 (5.6) Active TB 5 HZ 59 (4.4) 106 (3.8) sepsis (0.7) 20 Malignancies excluding NMSC 8 (0.3) Including 3 (0.2) 12 Depression (inc. mood disorders anxiety)/suicide/self-injury 210 (7.5) 9 *Occurring within infusion/injection date. herpes zoster; NMSC, non-melanoma skin cancer; OIs, opportunistic infections; tuberculosis Acknowledgements: Medical writing assistance provided by Helen Taylor, Fishawack Indicia Ltd., UK, part Health, funded GSK. Disclosure Interests: Daniel J. Wallace Speakers bureau: GSK, Consultant of: Tatsuya Atsumi Grant/research from: Mark Daniels Shareholder Employee Anne Hammer Paige Meizlik Holly Quasny Andreas Schwarting Novartis, Roche, Pfizer, Amgen, AbbVie, Actelion, Fengchun Zhang: None declared, David Roth