Long-term outcomes with belimumab in SLE: Post hoc pooled analysis of three trials

Results from a post hoc pooled analysis of three open-label, long-term extension (LTE) studies (BEL112233 [NCT00724867], BEL112234 [NCT00712933], and BEL112626 [NCT00583362]) evaluating the long-term effects of belimumab + standard therapy on glucocorticoid (GC) use, organ damage, and safety in patients with systemic lupus erythematosus (SLE) were published in Lupus Science & Medicine by Touma et al. Endpoints included the proportion of patients receiving GCs, antimalarials, and immunosuppressants over time; the most frequently reported maximum daily GC dose; the maximum daily GC dose over time; and the change from baseline in GC dose.

Key data: Of 1,299 patients in the modified intent-to-treat (mITT) population, ~50% reduced their GC dose to ≤7.5 mg/day within the first 3 years, increasing from 29% at Year 1 to 74% by Year 8. Mean change in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score did not exceed 0.3 (standard deviation [SD], 0.6) at Year 8 across all populations, with 79%, 76%, and 79% of patients in the mITT, high disease activity (HDA), and 5-year completer populations showing no SDI change, respectively. Overall, 97.5% of patients experienced ≥1 adverse event (AE) and 40.4% experienced ≥1 serious AE (SAE) up to 13 years; AEs leading to belimumab discontinuation occurred in 10.7% of patients. A total of 21 deaths were reported, three of which were considered possibly related to belimumab.

Key learning: In this pooled analysis, long-term belimumab + standard therapy in patients with SLE was associated with meaningful GC reduction and minimal organ damage accrual over 8 years, alongside a consistent safety profile over up to 13 years. The findings support belimumab as a long-term treatment option aligned with guideline-recommended SLE treatment goals.