GTC Drug Is First From Genetically Engineered Animals

GTC Biotherapeutics Inc. won U.S. Food and Drug Administration approval for the first medicine made from genetically engineered animals.
The intravenous therapy, ATryn, is purified from the milk of goats whose parents were injected with a human protein that helps prevent blood clots, GTC said today in a statement. The drug will be used for surgery patients or expectant mothers who have a rare genetic disorder that keeps them from making enough of the protein, called antithrombin.

About one person in 2,000 to 5,000 has the condition, hereditary antithrombin deficiency. Closely held Ovation Pharmaceuticals Inc., of Deerfield, Illinois, has rights to sell ATryn in the U.S. and will pay royalties to GTC. GTC has said annual U.S. sales of the drug will peak at $40 million to $50 million within five years. ATryn already is available in Europe.

“Bringing ATryn to market gives us the opportunity to make a meaningful difference in the lives of people” with the deficiency, said Jeffrey Aronin, Ovation’s chief executive officer, in the statement.

GTC, of Framingham, Massachusetts, manufactures ATryn from about 200 goats whose genome was created by injecting a goat embryo with antithrombin. Offspring produce the protein in their milk, which is purified, and infused as a drug.

Shares Decline

The shares fell 12 cents, or 15 percent, to 70 cents at 4 p.m. New York time in Nasdaq Stock Market composite trading. The drugmaker’s shares have more than doubled so far this year.

“The stock has been moving quite strongly upward after the panel vote, so I think most investors were assuming an approval by the FDA,” said Reni Benjamin, an analyst at Rodman & Renshaw in New York, in a phone interview today. “Sometimes we see this, that there’s a sell on the news.”

The approval follows a Jan. 9 recommendation by outside advisers to the FDA that ATryn be approved for those patients during surgery or childbirth, when the risk of clotting is high.

In addition to the standard review by the FDA’s drug regulators, the agency’s Center for Veterinary Medicine also approved the genetic makeup of the goats that produce ATryn.

People with hereditary lack of antithrombin can suffer deep vein thrombosis or clots in their legs, as well as lethal thromboembolism when such clots break off and travel to the lungs or brain.

Preventive therapy with a blood thinner such as warfarin or heparin is common, except during surgery or childbirth. At such times blood thinners are discontinued due to increased risk of bleeding, and people require antithrombin. The protein is currently available from human blood plasma.