Sparsentan versus Irbesartan in Focal Segmental Glomerulosclerosis
In the DUPLEX Phase III trial (n=371), there was no difference between the dual endothelin–angiotensin receptor antagonist sparsentan and irbesartan in terms of eGFR slope at week 108, despite a higher partial remission of proteinuria with the former.
Source:
New England Journal of Medicine
SPS commentary:
Editorial notes the trial did not achieve the goal of treatment with sparsentan: to decrease eGFR decline compared to irbesartan. The authors provide multiple speculative reasons as to why the observed reduction in proteinuria did not result in amelioration of decline in kidney function, such as the need for longer follow-up, trial population heterogeneity, and the relapsing nature of focal segmental glomerulosclerosis (FSG). It is hoped that further observation of trial participants in the open-label extension will provide an answer as to whether sparsentan offers “another arrow in the small quiver of armaments with which to treat FSG.”