Discovery of Orally Bioavailable Selective Inhibitors of the Sodium-Phosphate Cotransporter NaPi2a (SLC34A1)

ACS Med Chem Lett. 2018 Apr 12;9(5):440-445. doi: 10.1021/acsmedchemlett.8b00013. eCollection 2018 May 10.


Sodium-phosphate cotransporter 2a, or NaPi2a (SLC34A1), is a solute-carrier (SLC) transporter located in the kidney proximal tubule that reabsorbs glomerular-filtered phosphate. Inhibition of NaPi2a may enhance urinary phosphate excretion and correct maladaptive mineral and hormonal derangements associated with increased cardiovascular risk in chronic kidney disease-mineral and bone disorder (CKD-MBD). To date, only nonselective NaPi inhibitors have been described. Herein, we detail the discovery of the first series of selective NaPi2a inhibitors, resulting from optimization of a high-throughput screening hit. The oral PK profile of inhibitor PF-06869206 (6f) in rodents allows for the exploration of the pharmacology of selective NaPi2a inhibition.