Year-3 observational follow-up of belimumab safety (mortality and malignancies) in patients with SLE who completed a phase 4, 52-week, randomized, double-blind placebo-controlled safety study
Recommended Citation
Sheikh S, Wei C, Tegzova D, Stohl W, Acayaba de Toledo R, Mucenic T, Abello Banfi M, Maksimowicz-McKinnon K, Abud-Mendoza C, Navarra S, Garcia M, Garcia-De La Torre I, Kurrasch R, Fernandes S, Harris J, Muzaffar S, Lynn Fox N, Liu A, Quasny H, Roth D. Year-3 observational follow-up of belimumab safety (mortality and malignancies) in patients with SLE who completed a phase 4, 52-week, randomized, double-blind placebo-controlled safety study. Arthritis and Rheumatology 2021; 73(SUPPL 9):2696-2699.
Document Type
Conference Proceeding
Publication Date
9-1-2021
Publication Title
Arthritis and Rheumatology
Abstract
Background/Purpose: Belimumab (BEL) is a recombinant IgG1λ monoclonal antibody that is approved for treatment of systemic lupus erythematosus (SLE). Although clinical studies of BEL have demonstrated a favorable benefit-risk profile, varying incidence rates of mortality and adverse events of special interest, including malignancies, warrant further consideration. The Belimumab Assessment of Safety in SLE (BASE) placebo-( PBO)-controlled trial was conducted to assess long-term safety following BEL exposure.1 Methods: This was a post-treatment follow-up of the Phase 4, double-blind BASE study (GSK Study BEL115467; NCT01705977).1 A total of 4003 adults with active, autoantibody positive SLE received BEL (10 mg/kg IV) or PBO, plus standard therapy (ST) for 48 weeks. Following the treatment period, patients entered a Year 2-5 follow-up period in which they received physician-directed ST. All patients were contacted annually by telephone, including patients who discontinued treatment during the study. Mortality and new primary malignancies (including nonmelanoma skin cancer [NMSC]) were the only endpoints collected and rates were summarised. We present the data for the Year-3 follow-up by treatment received during the 52-week double-blind treatment period (Year 1). Results: Baseline characteristics at the start of the 52-week treatment for the Year-3 follow-up population (N=3266) were similar to those of the Year-1 double-blind study population (N=4003). By the Year-3 follow-up, cumulatively 12.0% and 10.9% of patients in the original BEL and PBO Year-1 treatment groups had received BEL as part of physician-directed care, respectively. In total (for both treatment groups), crude mortality rates were similar across Year 1 (0.87%), Year 2 (0.89%), and Year 3 (0.80%), whilst crude malignancy rates for Year 3 (0.52%) were numerically higher than Year 2 (0.30%), but similar to Year 1 (0.47%) (Table 1). Mortality and malignancy rates were lower in the BEL versus PBO Year-1 treatment group. Cumulative rates are shown in Table 2. Conclusion: Post-treatment follow-up results in Year 3 from BASE, the largest study of patients with SLE to date, provide continued support for the safety profile of BEL and remained consistent with the Year-2 follow-up data. No new safety concerns for BEL were identified in patients with active, autoantibody-positive SLE receiving ST. (Figure Presented).
Volume
73
Issue
SUPPL 9
First Page
2696
Last Page
2699