Session Information
Session Type: Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: Belimumab (BEL) is an approved treatment for active SLE and LN, in addition to standard therapy (ST). Despite BEL clinical studies demonstrating a favorable benefit–risk profile, varying incidence rates of mortality and adverse events of special interest, including malignancies, require further evaluation. This study aimed to assess the long-term safety of BEL therapy in patients with SLE.
Methods: This was a Year-5 post-treatment follow-up of the Phase 4, double-blind, placebo (PBO)-controlled Belimumab Assessment of Safety in SLE (BASE) study (GSK Study BEL115467; NCT01705977).1 Overall, 4003 adults with active, autoantibody-positive SLE received BEL (10 mg/kg intravenously [IV]) or PBO, plus ST, for 48 weeks. Patients then 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 in Year 1. Mortality and new primary malignancies (including nonmelanoma skin cancer) were the endpoints collected, and rates summarized. We present the final Year-5 follow-up data by treatment received during Year 1.
Results: Out of the Year-1 population, 77.0% (N=3081) were followed up through to Year 5 with a similar proportion of patients in each Year-1 treatment group. Baseline characteristics for the Year-5 follow-up population were similar to the Year-1 study population (N=4003). By the Year-5 follow-up, cumulatively 13.4% and 11.4% of patients in the BEL and PBO Year-1 treatment groups had received BEL as part of physician-directed care, respectively. Cumulative follow-up adjusted mortality rates were lower in the BEL vs PBO Year-1 treatment group by Years 2 to 5 (Year 5 BEL 0.61 vs PBO 0.96 per 100 patient-years; Table). Post hoc analyses of the Year 2–5 follow-up period showed that 96 patients (2.85%) died and the highest incidence of deaths by system organ class was infections and infestations (total 0.83%: BEL 0.83% and PBO 0.84%) and cardiac disorders (total 0.51%: BEL 0.29% and PBO 0.72%). Cumulative follow-up adjusted new primary malignancy patient incidence rates were lower in the BEL vs PBO Year-1 treatment group by Years 2 and 3, but similar by Years 4 and 5 (Year 5 BEL 0.40 vs PBO 0.38 per 100 patient-years; Table). Post hoc analyses of the Year 2–5 follow-up period showed that 46 patients (1.37%) developed new primary malignancies (BEL 1.42% and PBO 1.32%). The area most affected by neoplasm was the breast (total 0.36%: BEL 0.35% and PBO 0.36%).
Conclusion: The Year-5 follow-up results of BASE, the largest double-blind, placebo-controlled clinical trial in patients with SLE to date, support the safety of BEL therapy with no new BEL safety concerns identified in this analysis.
Funding: GSK
Reference
1 Sheikh SZ et al. Lancet Rheum 2020;3:e122–30
To cite this abstract in AMA style:
Sheikh S, Wei J, Tegzova D, Stohl W, Acayaba de Toledo R, Mucenic T, Abello Banfi M, Maksimowicz-McKinnon K, Abud-Mendoza C, Navarra S, García M, GARCÍA-DE LA TORRE I, Fernandes S, Harris J, Roy A, Olaiz J, WIlde P, Roth D. Year-5 Follow-up of Belimumab Safety (mortality and Malignancies) in Patients with Systemic Lupus Erythematosus (SLE) Who Completed a Phase 4, 52-week, Randomized, Double-blind Placebo-controlled Safety Study [abstract]. Arthritis Rheumatol. 2023; 75 (suppl 9). https://acrabstracts.org/abstract/year-5-follow-up-of-belimumab-safety-mortality-and-malignancies-in-patients-with-systemic-lupus-erythematosus-sle-who-completed-a-phase-4-52-week-randomized-double-blind-placebo-controlled-safe/. Accessed .« Back to ACR Convergence 2023
ACR Meeting Abstracts - https://acrabstracts.org/abstract/year-5-follow-up-of-belimumab-safety-mortality-and-malignancies-in-patients-with-systemic-lupus-erythematosus-sle-who-completed-a-phase-4-52-week-randomized-double-blind-placebo-controlled-safe/