OBJECTIVE: To examine long-term organ damage and safety following treatment with 
belimumab plus standard of care (SoC) in patients with systemic lupus 
erythematosus (SLE).
METHODS: Pooled data were examined from two ongoing open-label studies that 
enrolled patients who completed BLISS-52 or BLISS-76. Patients received 
belimumab every four weeks plus SoC. SLICC Damage Index (SDI) values were 
assessed every 48 weeks (study years) following belimumab initiation (baseline). 
The primary endpoint was change in SDI from baseline at study years 5-6. 
Incidences of adverse events (AEs) were reported for the entire study period.
RESULTS: The modified intent-to-treat (MITT) population comprised 998 patients. 
At baseline, 940 (94.2%) were female, mean (SD) age was 38.7 (11.49) years, and 
disease duration was 6.7 (6.24) years. The mean (SD) SELENA-SLEDAI and SDI 
scores were 8.2 (4.18) and 0.7 (1.19), respectively; 411 (41.2%) patients had 
organ damage (SDI = 1: 235 (23.5%); SDI ≥ 2: 176 (17.6%)) prior to belimumab. A 
total of 427 (42.8%) patients withdrew overall; the most common reasons were 
patient request (16.8%) and AEs (8.5%).The mean (SD) change in SDI was +0.2 
(0.48) at study years 5-6 (n = 403); 343 (85.1%) patients had no change from 
baseline in SDI score (SDI +1: 46 (11.4%), SDI +2: 13 (3.2%), SDI +3: 1 (0.2%)). 
Of patients without organ damage at baseline, 211/241 (87.6%) had no change in 
SDI and the mean change (SD) in SDI was +0.2 (0.44). Of patients with organ 
damage at baseline, 132/162 (81.5%) had no change in SDI and the mean (SD) 
change in SDI was +0.2 (0.53). The probability of not having a worsening in SDI 
score was 0.88 (95% CI: 0.85, 0.91) and 0.75 (0.67, 0.81) in those without and 
with baseline damage, respectively (post hoc analysis).Drug-related AEs were 
reported for 433 (43.4%) patients; infections/infestations (282, 28.3%) and 
gastrointestinal disorders (139, 13.9%) were the most common.
CONCLUSION: Patients with SLE treated with long-term belimumab plus SoC had a 
low incidence of organ damage accrual and no unexpected AEs. High-risk patients 
with pre-existing organ damage also had low accrual, suggesting a favorable 
effect on future damage development.