OBJECTIVES: Evaluate the cost-utility of belimumab to treat active lupus nephritis (LN) in Brazilian patients assisted by private healthcare.

METHODS: The BLISS-LN study demonstrated superiority of belimumab combined with standard therapy (ST) versus ST alone (cyclophosphamide followed by azathioprine or mycophenolate mofetil) in protecting renal function measured by glomerular filtration rate (GFR). A Markov model was constructed with six health states: three related to estimated GFR (stage I/II chronic kidney disease [CKD]; stage III; stage IV) and three related to end-stage kidney disease (dialysis-dependent; kidney transplant; post-transplant with dialysis dependence). With annual cycles and a lifetime horizon, transition probabilities in the first two years were extracted from BLISS-LN; subsequent years were based on relative transition rates from a longitudinal study. Utilities and mortality risk were derived from CKD and lupus burden studies. Unit costs were based on Brazilian private health perspective; annual discount rate was 5% for costs and outcomes. Treatment duration with belimumab was three years with continuous ST.

RESULTS: Base case resulted in BRL 139.885/QALY versus ST alone. In probabilistic sensitivity analysis, using the public system standard for severe illnesses (BRL 120,000.00/QALY) as the Brazilian private system lacks a willingness-to-pay threshold, the result was cost-effective in 51.3% of simulations.

CONCLUSIONS: Belimumab plus ST reverses or slows the progression of CKD, improving patients' quality of life and mortality. It is more expensive but provides savings on dialysis and transplantation.