Regeneron’s Arcalyst Fails to Win U.S. Backing for Gout

Regeneron Pharmaceuticals Inc. (REGN), the maker of the autoinflammatory drug Arcalyst, failed to win U.S. approval to expand the use of the medicine for patients undergoing gout treatments.

The Food and Drug Administration asked in a complete response letter for more data regarding the use of the injection to treat flares of joint pain caused by gout treatments, the Tarrytown, New York-based company said yesterday in a statement. Arcalyst was cleared for sale in February 2008 to treat a rare genetic autoinflammatory disease.

FDA staff raised concerns in a May 4 report that the benefit of expanding the drug’s use may be too small to justify a 1 in 244 risk of developing cancer from taking the medicine. Arcalyst was linked to six cases of malignancies, including prostate and breast cancers. Advisers to the agency recommended against approval of the new use citing inadequate safety data.

“Regeneron is reviewing the complete response letter and will determine appropriate next steps,” George D. Yancopoulos, president of Regeneron Laboratories, said in the statement.

Expanded approval would have added $128 million to $200 million to Regeneron’s annual sales of the drug by 2015, according to two analyst estimates compiled by Bloomberg earlier this year. Arcalyst generated about $20 million for the company last year, according to data compiled by Bloomberg.

Regeneron declined less than 1 percent to $134.65 at the close in New York. The company’s shares have more than doubled in the past 12 months.

FDA Request

The FDA also asked for information about chemistry, manufacturing and controls related to a proposed new dosage form of the medicine, Regeneron said in the statement.

Gout treatments include Takeda Pharmaceutical Co. (4502)’s Uloric and a generic version, allopurinol. They lower levels of uric acid, or bodily waste, that cause gout in excess levels, which manifests through joint pain, according to the National Institutes of Health. Regeneron is seeking approval of Arcalyst to prevent gout flares for people initiating uric-acid lowering therapies.

Allopurinol breaks up uric acid crystals that can cause flares of joint pain that may lead patients to stop taking their medication, the company said. About 750,000 gout patients begin taking allopurinol each year, according to Regeneron.

To contact the reporter on this story: Anna Edney in Washington at

To contact the editor responsible for this story: Reg Gale at

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