UPDATE 2-Pig virus concern for Solvay enzyme -FDA

(Recasts first paragraph, adds virus details, Creon revenues)

By Susan Heavey

WASHINGTON, Nov 28 (Reuters) - U.S. health regulators are concerned about the risk of patients contracting viruses from pig glands used to make Solvay Pharmaceuticals Inc's pancreatic enzyme product Creon, according to documents released on Friday.

The comments come as the U.S. Food and Drug Administration requires pancreatic enzyme products to show their safety and effectiveness as a condition of remaining on the market.

Solvay Pharmaceuticals, a unit of Brussels-based Solvay SA (SOLB.BR), is seeking FDA approval to continue to sell its Creon capsules for patients with exocrine pancreatic insufficiency, a relatively rare condition marked by a lack of enzymes needed to digest food.

There is "great concern" that some viruses have the potential to cross species, the FDA staff said, but added that the enzyme products "are absolutely medically necessary."

"Given the occurrence of these viruses in European and U.S. sourced swine, we believe that the risk associated from the use of Creon should be reduced," they wrote.

The FDA released the documents ahead of a Dec. 2 advisory committee meeting to discuss whether to formally approve Creon. While the agency will make the final decision, it often follows the recommendations of its outside advisers.

Pancreatic enzyme products blend a variety of digestive enzymes that help patients with disorders such as cystic fibrosis or chronic pancreatitis properly absorb nutrients.

The are derived from the pancreatic glands of pigs, which are known to transmit some viruses to people such as influenza and hepatitis, the FDA said. While pigs in the U.S. and Europe are vaccinated against some viruses, they are not protected against others that could pose a risk, such as porcine parvoviruses.

Patients with cystic fibrosis, an inherited disease that affects about 30,000 in the United States, generally take such enzymes for life, according to the FDA and the Cystic Fibrosis Foundation.

Pancreatic enzymes have been sold in the Unites States for decades -- before companies were required to submit data to the FDA for approval. Solvay's Creon has been available since 1987.

But concerns arose in the 1990s that they might cause colon damage, and in 2004, the agency ordered all pancreatic enzyme manufacturers to conduct clinical trials and undergo a formal FDA review in order to continue selling their products.

Pancreatic enzyme makers have until April 2010 to win FDA approval or they must stop sales.

Creon is the first to move far enough in the FDA review process to require an advisory meeting, Solvay Pharmaceuticals spokesman Neil Hirsch told Reuters earlier this week.

Creon is approved in more than 70 countries and saw 2007 global sales of 191 million euros ($243 million), less than 2 percent Solvay SA's revenues of 9.6 billion euros ($12.2 billion) in 2007.

Although the FDA is currently reviewing Solvay's product, "there are numerous other manufacturers of (pancreatic) products that have similar and perhaps greater concerns," regarding virus control, FDA staff said.

Solvay, in separate documents also released on Friday, said it has taken steps to reduce the risk of infection, including screening finished products.

"As with any products derived from animal tissues, the potential risk for infectious disease due to the transmission of an infective agent cannot be totally excluded," it wrote.

While Solvay's product is made using glands from U.S. and European-raised pigs, concerns have been raised about other medical products made using pigs from China.

Earlier this year, FDA officials found a contaminant in batches of Baxter International Inc's (BAX.N) blood-thinning drug heparin, which is derived from pig intestines. The drug's key ingredient came from pigs in China.

The documents on Solvay's Creon were posted on the FDA website here ($=.7869 euro) (Reporting by Susan Heavey, editing by Tim Dobbyn)