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# Recognize Auryxia Regulatory Exclusivity: Keryx Petition
- URL: https://www.fdaweb.com/recognize-auryxia-regulatory-exclusivity-keryx-petition/
- Published: 2018-08-28T12:00:00.000Z
- Updated: 2026-09-15T00:28:36.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5142212

Keryx Biopharmaceuticals is asking FDA to recognize regulatory exclusivity for its Auryxia (ferric citrate) oral tablets containing “a novel mixture of covalent metal-ion complexes as its active moiety.” The company’s [petition](https://www.regulations.gov/contentStreamer?documentId=FDA-2018-P-3284-0001&attachmentNumber=1&contentType=pdf&ref=fdaweb.com) says that although the agency approved Auryxia nearly four years ago, it still has not made a determination about whether it should receive new chemical entity (NCE) exclusivity. And, the petition says, FDA also has not stated that Auryxia received three-year exclusivity for a new indication, even though the indication was supported with new clinical data.

The petition asks that FDA: 

- recognize that Auryxia earned five-year NCE exclusivity based on its novel active moiety;
- recognize that Auryxia earned three years of exclusivity based on the approval of a new indication in 2017 for treating iron deficiency anemia in patients with non-dialysis dependent chronic kidney disease;
- require that ANDAs referencing Auryxia be supported with **(1)** comparative physio-chemical data demonstrating active pharmaceutical ingredient (API) sameness with Auryxia based on a qualitative and quantitative match regarding major ions and counterions and **(2)** *in vivo* bioequivalence data to address the drug’s systemic effects; and
- revise the agency’s product-specific guidance about ferric citrate oral tablets to recommend that bioequivalence be established with an *in vivo* study and that API sameness be established based on a qualitative and quantitative match with regard to the major ions and counterions.