Belimumab extension studies report limited SLE organ damage accrual over eight years

A post hoc analysis published in Lupus Science & Medicine pooled three long-term extension studies involving patients who completed BLISS-52, BLISS-76 or LBSL02. All received intravenous belimumab 10 mg/kg every 28 days plus standard therapy. Of 1,304 enrolled patients, 1,299 received at least one dose and entered the analysis; 94% were women, with a mean age of 39.7 years. Endpoints included concomitant medication use, organ damage accrual through eight years and safety through 13 years.

Glucocorticoids were used by 94.1% of patients at some point after their first belimumab dose. Approximately 50% reduced their glucocorticoid dose to ≤7.5 mg/day within the first three years, rising to 73.6% by the end of year eight. Mean changes in the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index did not exceed 0.3 through year eight. Over follow-up of up to 13 years, 97.5% experienced an adverse event, 40.4% experienced a serious adverse event and 10.7% had adverse events leading to belimumab discontinuation.

The authors reported no new safety concerns. These findings describe reduced glucocorticoid exposure and limited damage accrual during prolonged treatment, but do not establish that belimumab prevented organ damage. The post hoc, open-label design, absence of a concurrent control group and selection of parent-study completers limit interpretation. The supplied abstract does not provide numbers remaining under observation at later time points.