Keryx kidney drug gets OK but comes with warnings

Staff Writer
Columbus CEO

NEW YORK (AP) — Keryx Biopharmaceuticals shares fell Friday as the company received U.S. approval for its pill to treat kidney disease complications but the clearance required unexpected safety warnings.

The Food and Drug Administration approved the company's ferric citrate drug to treat patients on dialysis with hyperphosphatemia, or elevated levels of phosphates, which can increase the risk of heart disease, bone density problems and death.

Keryx previously highlighted the drug's ability to also boost patients' iron levels, a feature the company said would enable patients to reduce use of anemia drugs often taken by dialysis patients. However, the FDA-approved label actually warns that the drug can cause "iron overload," and that doctors must monitor patients' iron levels while taking the drug.

Shares of Keryx Biopharmaceuticals Inc. fell almost 6 percent in late afternoon trading, dropping $1.05 to $16.94. They had been as low as $14.80 earlier in the day as trading was halted ahead of a company conference call with industry analysts.

"This is a drug that has demonstrated a clear ability to benefit a very sick and burdened patient population," CEO Ron Bentsur said in an interview with The Associated Press. Benstur said the company will launch the drug in the U.S. in the next 12 weeks.

Keryx estimates that between 350,000 and 375,000 U.S. dialysis patients take medication to control their phosphate levels, representing a total market of $1.2 billion.

Ferric citrate is designed to be taken in two pills with each meal, for a daily regimen of six pills.

The company had initially planned to market the drug under the brand name Zerenex, though the FDA recently ruled that the name was too similar to a drug already on the market. Keryx plans to develop a new brand name ahead of the drug's launch.

It's the first U.S. product approval for the New York-based drugmaker, which licensed ferric citrate from a Taiwanese drugmaker in 2005. Keryx has rights to market the drug in North America, Europe and Japan, where the pill launched in May.

The company plans to soon begin late-stage testing of the drug in kidney disease patients who are not yet on dialysis.

More than 20 million people in the U.S. have chronic kidney disease and roughly 400,000 receive dialysis treatment, in which a machine filters waste from the blood in place of healthy kidneys.