Keryx Biopharmaceuticals Announces FDA Acceptance for Filing of Zerenex(TM) New Drug Application

Keryx Biopharmaceuticals Announces FDA Acceptance for Filing of Zerenex(TM)
New Drug Application

NEW YORK, Oct. 8, 2013 (GLOBE NEWSWIRE) -- Keryx Biopharmaceuticals, Inc.
(Nasdaq:KERX) today announced that its New Drug Application (NDA) for Zerenex™
(ferric citrate coordination complex) has been accepted for filing by the U.S.
Food and Drug Administration (FDA). The acceptance for filing of the NDA
indicates the determination by the FDA that the application is sufficiently
complete to permit a substantive review.

Ron Bentsur, the Company's Chief Executive Officer, said, "We are very pleased
with the FDA's acceptance for filing of our NDA for Zerenex, as this
represents an important achievement in the development of Zerenex.We believe
that Zerenex has the potential to make a meaningful difference in the lives of
patients with chronic kidney disease on dialysis, and we look forward to
continuing to work with the FDA in its review process of the Zerenex NDA."

The Company's NDA, submitted on August 7, 2013, seeks approval for the
marketing and sale of Zerenex as a treatment for elevated serum phosphorus
levels, or hyperphosphatemia, in patients with chronic kidney disease (CKD) on
dialysis. Included in the NDA filing are safety and efficacy datasets derived
from the Company's Phase 3 registration program, which was conducted pursuant
to a Special Protocol Assessment (SPA) agreement with the FDA, as well as
safety and efficacy data from several additional studies, including four Phase
3 studies conducted in Japan in CKD patients on dialysis.

Keryx holds a worldwide license (except for certain Asian Pacific countries)
to Zerenex from Panion & BF Biotech, Inc. The Japanese rights are sublicensed
by Keryx to Japan Tobacco Inc. (JT) and Torii Pharmaceutical Co., Ltd.
(Torii). On January 7, 2013, JT announced the filing of its NDA with the
Japanese Ministry of Health, Labour and Welfare for marketing approval of
ferric citrate in Japan for the treatment of hyperphosphatemia in patients
with CKD.

Zerenex is also in Phase 2 development in the U.S. for the management of
elevated phosphorus and iron deficiency in anemic patients with Stage 3 to 5
non-dialysis dependent CKD.

About Special Protocol Assessments

The Special Protocol Assessment (SPA) process is a procedure by which the FDA
provides official evaluation and written guidance on the design and size of
proposed protocols that are intended to form the basis for a new drug
application. Final marketing approval depends on the efficacy and safety
results, including the adverse event profile, and an evaluation of the
benefit/risk of treatment demonstrated in the Phase 3 clinical program. The
SPA agreement may only be changed through a written agreement between the
sponsor and the FDA, or if the FDA becomes aware of a substantial scientific
issue essential to product efficacy or safety. For more information on Special
Protocol Assessment, please visit:
http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm080571.pdf.

About Keryx Biopharmaceuticals, Inc.

Keryx Biopharmaceuticals is focused on the acquisition, development and
commercialization of medically important pharmaceutical products for the
treatment of renal disease. Keryx is developing Zerenex (ferric citrate
coordination complex), an oral, ferric iron-based compound that has the
capacity to bind to phosphate and form non-absorbable complexes. Keryx has
completed a U.S.-based Phase 3 clinical program for Zerenex for the treatment
of hyperphosphatemia (elevated phosphate levels) in patients with chronic
kidney disease on dialysis, conducted pursuant to a Special Protocol
Assessment (SPA) agreement with the Food and Drug Administration (FDA), and
the Company's New Drug Application is currently under review by the FDA. The
Marketing Authorization Application filing with the European Medicines Agency
(EMA) is pending submission. Zerenex is also in Phase 2 development in the
U.S. for the management of elevated phosphorus and iron deficiency in anemic
patients with Stages 3 to 5 non-dialysis dependent chronic kidney disease. In
addition, 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. Keryx is headquartered in New York City.

Cautionary Statement

Some of the statements included in this press release, particularly those
relating to the results of clinical trials, the clinical benefits to be
derived from Zerenex (ferric citrate coordination complex), regulatory
submissions and the timing of any such review, approvals, the commercial
opportunity and competitive positioning, and any business prospects for
Zerenex, may be forward-looking statements that involve a number of risks and
uncertainties. For those statements, we claim the protection of the safe
harbor for forward-looking statements contained in the Private Securities
Litigation Reform Act of 1995. Among the factors that could cause our actual
results to differ materially are the following: acceptance of the NDA filing
does not represent final evaluation of the adequacy of the data submitted in
the NDA; whether the FDA will complete its review of the NDA on a timely
basis; the risk that the FDA, EMA, and Japanese Ministry of Health, Labour and
Welfare ultimately deny approval of the U.S. NDA, MAA and Japanese NDA,
respectively; the risk that SPAs are not a guarantee that the FDA will
ultimately approve a product candidate following filing acceptance; whether
the FDA and EMA will concur with our interpretation of our Phase 3 study
results, supportive data, or the conduct of the studies; whether, Zerenex, if
approved, will be successfully launched and marketed; and other risk factors
identified from time to time in our reports filed with the Securities and
Exchange Commission. Any forward-looking statements set forth in this press
release speak only as of the date of this press release. We do not undertake
to update any of these forward-looking statements to reflect events or
circumstances that occur after the date hereof. This press release and prior
releases are available at http://www.keryx.com. The information found on our
website, and the FDA website, is not incorporated by reference into this press
release and is included for reference purposes only.

CONTACT: Lauren Fischer
         Director - Investor Relations
         Keryx Biopharmaceuticals, Inc.
         Tel: 212.531.5965
         E-mail: lfischer@keryx.com

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