LAUSR

Belimumab was approved in the United Kingdom (UK) in 2016 as add-on therapy for patients with auto-antibody positive systemic lupus erythematosus (SLE) and high disease activity refractory to standard treatment. Data regarding the effectiveness of belimumab outside clinical trials has been published in worldwide SLE cohorts but not the UK. Here, we describe the efficacy of add-on belimumab therapy in SLE patients from a large London tertiary centre. We performed a retrospective, intention-to-treat analysis of clinical and biochemical outcomes, at 6 and 12 months, post receipt of at least 1 infusion of belimumab in SLE patients attending Guy’s and St Thomas’ NHS Trust (April 2013-November 2021). Outcomes assessed included: the Safety of Estrogen in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI), anti-dsDNA ELISA titre, complement C3 and C4 titres, urine protein:creatinine ratio (uPCR) and daily prednisolone dose. Analyses performed using SPSS statistics 27. 63 patients (56 female [88.9%], median age 38 years, self-reported race/ ethnicity; 24 Black [38.1%], 24 White [38.1%], 13 Asian [20.6%]) with SLE as defined by the 1997 ACR criteria were included. An 8-point reduction in median SELENA-SLEDAI was evident at 6 months after commencing belimumab, which increased to 9 points at 12 months (n = 28, p < 0.001)(Table 1). Improvements in C3/ C4 titres were also observed at 6 months (0.13-point and 0.04-point increase in median C3/ C4 titres respectively, n = 45, p < 0.001). At 12 months, significant reductions in median anti-dsDNA titre (16.50-point reduction, n = 42, p < 0.001) and median daily prednisolone dose were evident (2.50mg reduction, n = 51, p < 0.001). No change in uPCR was noted (n = 23, p = 0.956). 40/47 (85%) patients with a SELENA-SLEDAI score recorded at 6 months achieved the National Institute for Health and Care Excellence (NICE) defined target for a >/= 4-point reduction in SELENA-SLEDAI. No significant associations between baseline demographic variables and SELENA-SLEDAI score at 6 months, or prednisolone dose at 12 months, were evident. We observed a significant improvement in SLE disease activity as determined by SELENA-SLEDAI score measured at 6 and 12 months after starting belimumab, and a significant steroid-sparing effect at 12 months. These findings are similar to published worldwide data. Disclosure G. Mallett: None. C. Hession: None. M. Fernando: Other; MF has received speaker fees from GlaxoSmithKline (GSK) and Union Chimique Belge (UCB), as well as conference fees from GSK.