Belimumab in Lupus Nephritis

To the Editor: Furie et al. (Sept. 17 issue)(1) report the results of the Belimumab International Study in Lupus Nephritis (BLISS-LN), a large, randomized trial of intravenous belimumab as compared with placebo when added to standard therapy (mycophenolate mofetil or cyclophosphamide-azathioprine) in adults with active lupus nephritis. There was adequate follow-up time, but several points need clarification. Notably, one third of the patients were not taking a renin-angiotensin system (RAS) blocker at baseline. Although initiation of an RAS blockade was encouraged, it would have to have been initiated before week 24; treatment would otherwise be considered to have failed. Since . . .