BAY767

BAY767 is an orally bioavailable, highly selective small molecule inhibitor of the renal sodium-phosphate cotransporter 2a (NaPi-IIa, also known as Npt2a or SLC34A1). Developed by Bayer, BAY767 selectively blocks NaPi-IIa with nanomolar potency (IC50 of ~4 nM) and exhibits >100-fold selectivity over other phosphate transporters such as NaPi-IIb, NaPi-IIc, and PiT-1. By inhibiting renal phosphate reabsorption in the proximal tubule, BAY767 promotes phosphaturia, thereby reducing systemic phosphate overload (hyperphosphatemia) and lowering circulating levels of parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23). In preclinical rodent models of chronic kidney disease (CKD) and hyperphosphatemia, BAY767 has demonstrated efficacy in preventing vascular and renal calcifications and improving survival.