OP0254 A propensity score-matched (PSM) analysis of organ damage in patients with systemic lupus erythematosus (SLE) from the pooled bliss long-term extension (LTE) trials versus the toronto lupus cohort (TLC)

Background A pooled analysis of the open-label BLISS LTE studies (BEL112233/BEL112234) reported low levels of organ damage accrual (measured by Systemic Lupus International Collaborating Clinics [SLICC]/American College of Rheumatology Damage Index [SDI]) in patients who received belimumab (BEL) plus standard therapy (SoC) over a 5 year period. However, the LTE studies had no SoC arm. This post-hoc study (206347) used PSM to match BLISS LTE patients to TLC patients to define a SoC treatment comparison cohort. Objectives To assess damage accrual in patients with SLE treated with BEL plus SoC compared with PSM patients from the TLC treated with SoC alone. Methods This analysis compared the mean SDI change from baseline (over 5 years), time to SDI event (on all patients with ≥1 year follow-up), and magnitude of year-to-year SDI change (over 5 years), from baseline to Year 5 in patients treated with BEL plus SoC (pooled United States [US] and non-US data from the BLISS LTE studies), and SoC alone. Patients in the LTE and TLC were 1:1 PSM based on 16 clinical variables with a propensity score calliper ±20%. Regression augmented inverse propensity score weighting (IPSW) tested the robustness of the PSM results. Results For the 5 year analysis, 181 LTE patients were matched to 181 TLC patients (mean bias 3.8%) from a larger pool of 973 patients (BLISS LTE n=592; TLC n=381). Time-to-event PSM resulted in 323 LTE and 323 TLC patients (mean bias 3.7%) from a larger pool of 1541 patients (BLISS LTE n=949; TLC n=592). The mean SDI score change from baseline in the BEL group was 0.265 (95% confidence interval [CI]: 0.180, 0.350) compared with 0.718 (95% CI: 0.547, 0.889) in the SoC group, resulting in a BEL treatment effect of –0.453 fewer SDI units (95% CI: –0.646,–0.260; p Conclusions This PSM analysis demonstrates that BEL plus SoC reduces, and slows the rate of organ damage progression and reduces the magnitude of progression compared with SoC alone. Acknowledgements Study funded by GSK. Emma Hargreaves, MA, of Fishawack Indicia Ltd, UK, provided editorial assistance funded by GSK. Disclosure of Interest M. Urowitz Grant/research support from: GSK, Consultant for: GSK, R. Ohsfeldt Employee of: GSK contractors with Medical Decision Modelling Inc., R. Wielage Employee of: GSK contractors with Medical Decision Modelling Inc., J. Dever Employee of: GSK contractors with Medical Decision Modelling Inc., M. Zakerifar Employee of: GSK contractors with Medical Decision Modelling Inc., Y. Asukai Shareholder of: GSK, Employee of: GSK, S. Ramachandran Shareholder of: GSK, Employee of: GSK, A. Joshi Shareholder of: GSK, Employee of: GSK