Sodium Phosphate Cotransporter Inhibitor

EOS789 is an orally active sodium-dependent phosphate transporter inhibitor, with IC₅₀ values of 6.8, 1.5, and 1.7 μM against human NaPi-IIb, PiT-1, PiT-2, respectively; and IC₅₀ values of 3.9, 1.9, and 1.7 μM against rat NaPi-IIb, PiT-1, PiT-2, respectively. EOS789 inhibits intestinal phosphate absorption, increases fecal phosphate excretion, reduces urinary phosphate excretion, and decreases the levels of serum phosphate, FGF23, and adult parathyroid hormone. EOS789 ameliorates ectopic thoracic aortic calcification, renal injury and hyperphosphatemia, and inhibits the expression of fibrosis markers. EOS789 can be used for the research of hyperphosphatemia and chronic kidney disease-mineral and bone disorder (CKD-MBD).

NaPi2b-IN-1 is a potent and orally active inhibitor of sodium-dependent phosphate transport protein 2b (NaPi2b) with an IC₅₀ of 64 nM. NaPi2b is primarily expressed in the small intestine, lungs, and testes and plays an important role in phosphate homeostasis. NaPi2b-IN-1 has the potential for the research of hyperphosphatemia.