TOPLINE

Patients with systemic lupus erythematosus (SLE) who were treated with belimumab plus standard therapy showed a reduction in their glucocorticoid use and had minimal progression of organ damage over 8 years. Over 13 years, belimumab appeared to be well tolerated, with most adverse events (AEs) being infections and infestations.

METHODOLOGY

• Researchers conducted a post hoc analysis of pooled data from three international open-label, long-term extension (LTE) studies (extensions of one phase 2 and two phase 3 parent studies) to assess the effect of belimumab on concurrent use of SLE medications, organ damage accrual, and the safety profile of belimumab in patients with SLE.  
• A total of 1299 patients with SLE (mean age, 39.7 years; 94% women) who were enrolled in the LTE studies received at least one dose of intravenous belimumab at 10 mg/kg every 28 days along with standard therapy. The mean disease duration was 7.2 years. 
• The main endpoints were the proportion of patients using glucocorticoids, antimalarials, and immunosuppressants at any time following the first dose of belimumab, and organ damage accrual, assessed as changes in the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score from baseline. 
• Safety outcomes comprised the incidence of AEs, serious AEs, and AEs leading to treatment discontinuation.
• At baseline, glucocorticoids were used by 81.1% of patients, antimalarials by 67.4%, and immunosuppressants by 47.6%.

TAKEAWAY

• At any time following the initial dose of belimumab, the most commonly used SLE medications were glucocorticoids (used by 94.1% of patients), antimalarials (used by 74.6%), and immunosuppressants (used by 56.4%).
• The proportion of patients who reduced their daily glucocorticoid dose to ≤ 7.5 mg/d went up from 29% in the first year to 74% in the eighth year. Conversely, the proportion of patients who increased their dose to > 7.5 mg/d remained stable (8% and 10% in years 1 and 8, respectively).
• The mean change in SDI score from baseline did not exceed 0.3, and 79% of patients had no increase in score by year 8.
• During follow-up of up to 13 years, 97.5% of patients experienced at least one AE, 40.4% experienced at least one serious AE, and 10.7% had at least one AE leading to treatment discontinuation. Infections and infestations were the most common AEs; 16.4% experienced infections of special interest, including herpes zoster (10.5%), opportunistic infections (3.4%), serious infections of special interest (3.0%), sepsis (1.9%), and active tuberculosis (0.3%).

IN PRACTICE

"[B]elimumab can help patients achieve the goals outlined in treatment guidelines, which may benefit patients and healthcare systems. Robust and consistent safety data for up to 13 years support the well-established favourable safety profile of belimumab, with no new safety concerns, and help healthcare professionals and patients make informed decisions on the treatment of SLE," the authors wrote.

SOURCE

This study was led by Zahi Touma, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada. It was published online on October 05, 2026, in Lupus Science & Medicine.

LIMITATIONS

The study was post hoc in design and lacked a control group and mandated glucocorticoid tapering. The study included self-selected patients continuing from parent trials, which may have introduced potential bias toward belimumab responders.

DISCLOSURES

The post hoc analysis received funding from GSK. Several authors declared receiving consulting fees, grant/research support, support for attending meetings or travel, and/or speaker fees or honorariafrom various pharmaceutical, biopharmaceutical, or biotechnology companies, including GSK, as well as other sources. Two authors declared being employees of and holding financial equities in GSK.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.