Zerenex (ferric citrate) is an oral, ferric iron-based compound that has the capacity to bind to phosphate and form non-absorbable complexes. Zerenex has completed a U.S.-based Phase 3 clinical program for the treatment of hyperphosphatemia (elevated phosphate levels) in patients with end-stage renal disease, conducted pursuant to a Special Protocol Assessment (SPA) agreement with the FDA. The submission of an NDA with the FDA and a MAA with the EMA is pending. Zerenex is also in Phase 2 development in the U.S. for the management of phosphorus and iron deficiency in anemic patients with Stage 3 to 5 non-dialysis dependent chronic kidney disease. Keryx's Japanese partner, Japan Tobacco Inc. and Torii Pharmaceutical Co., Ltd. has filed its New Drug Application for marketing approval of ferric citrate in Japan for the treatment of hyperphosphatemia in patients with chronic kidney disease.