NEW YORK (TheStreet) -- Shares of Keryx Biopharmaceuticals (KERX) - Get Report are tumbling 29.55% to $5.18 on heavy trading volume early Monday afternoon as the company expects production issues to interrupt the supply of its only approved drug. 

Supply of the renal medication Auryxia should be restored in the fourth quarter, the company said in a statement. 

Maxim consequently downgraded shares to "hold" from "buy," Reuters reports.

"Just as Auryxia was building traction, it is a disappointment to see a manufacturing disruption," the firm wrote in a note. "While we believe the long-term picture is still robust and intact, the short term will be difficult and is not predictable."

The supply disruption led Keryx to withdraw its full-year financial guidance, though CFO Scott Holmes said the company is nonetheless "well positioned financially to manage through this interruption in supply of Auryxia."

For the second quarter, Keryx reported a loss of 42 cents per share on $9.3 million in revenue. Analysts were looking for a loss of 28 cents per share on $8.5 million in revenue. 

About 7.67 million shares of Keryx have been traded so far today vs. its average trading volume of roughly 1.26 million shares a day. 

Separately, TheStreet Ratings team rates the stock as a "sell" with a ratings score of D-.

Keryx's weaknesses include its deteriorating net income, disappointing return on equity, generally disappointing historical performance in the stock itself and generally high debt management risk.

You can view the full analysis from the report here: KERX

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.

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