Impact of belimumab on fatigue and disease activity in the management of systemic lupus erythematosus

Abstract Objective This prospective cohort study evaluated longitudinal changes in fatigue among systemic lupus erythematosus (SLE) patients who are treated with belimumab as add-on therapy over 12 months. Methods This was a prospective, multicenter observational cohort study carried out at two tertiary care centers in Saudi Arabia between April 2022 and April 2023. We collected data prospectively from clinical visits at baseline, 6, and 12 months. Data included demographic and clinical characteristics, comorbidities, prior and current medications, disease activity evaluation, patient-reported outcomes, and laboratory parameters, including hematological profile, renal and liver function tests, complement levels (C3, C4), inflammatory markers, and immunological markers. The primary conclusion was change in fatigue throughout 12 months, assessed using the Fatigue Severity Scale (FSS), and the Visual Analog Fatigue Scale (VAFS). Secondary conclusions included changes in disease activity assessed by Systemic Lupus Erythematosus Disease Activity Index-2000(SLEDAI-2K) and patient global assessment (PtGA). Results Thirty-six SLE patients were included, 83.3% were female, with mean disease duration 10.42 years (± 6.1). FSS and VAFS improved significantly with a p:0.001 at 6 & 12 months of belimumab therapy. The mean SLEDAI score decreased from 10.83 ± 8.4 to 5.19 ± 4.3 then to 2.65 ± 3.3, at baseline, month 6 and month 12 respectively with P value < 0.001. Belimumab in lupus nephritis patient showed significant improvement in FSS, SLEDAI, proteinuria and the complement levels. Conclusion Belimumab, when used as add-on therapy, was associated with considerable improvement in fatigue, disease activity, and patient-reported outcomes over 12 months in SLE patients. These findings support the potential efficiency of belimumab in regular clinical practice.