Within-trial economic analysis of flare data from the BLISS-SC trial of subcutaneous belimumab in systemic lupus erythematosus

OBJECTIVE: The management of systemic lupus erythematosus (SLE) flares can incur substantial healthcare costs. In the phase III BLISS-SC trial, subcutaneous (SC) belimumab 200 mg plus standard therapy was associated with significant reductions in time to severe flare, and risk of flares, versus placebo plus standard therapy, in adults with active SLE. We evaluated whether the reduction in SLE flares with belimumab SC plus standard therapy translated to lower healthcare costs. METHODS: A retrospective, post hoc economic analysis of BLISS-SC data was conducted. Unit costs per flare from claims data were estimated and applied to flares observed in BLISS-SC to quantify costs associated with treating severe flares (primary objective) or flares of any severity (secondary objective). RESULTS: Of 836 patients (n=556 belimumab, n=280 placebo) analysed (94.4% female, mean (standard deviation, SD) age 38.6 (12.3) years), 13.2% and 62.8% had experienced a severe or mild/moderate flare, respectively. Mean (SD) unit costs per severe, moderate, mild or mild/moderate flare were US$9273 (38 800), US$3048 (9321), US$1671 (6202) and US$2303 (7821), respectively. Adjusted mean costs of treating flares were significantly lower with belimumab SC plus standard therapy than placebo plus standard therapy (severe flare, US$927 lower, p<0.001; flare of any severity, US$1379 lower, p<0.001). CONCLUSIONS: This economic analysis of data from the BLISS-SC trial revealed significant cost reductions were associated with treating SLE flares with belimumab SC plus standard therapy versus placebo plus standard therapy. These findings may help to inform decision making about introducing belimumab to healthcare systems. TRIAL REGISTRATION NUMBER: NCT01484496.