ZymoGenetics Plays Hardball, Asks FDA to Pull Competing Drug Off Market Because of Safety

ZymoGenetics isn’t giving up on its sole marketed product, and it’s playing some hardball to fight for it. The Seattle biotech company said today it is asking the FDA to yank its top competitor’s drug off the market because, it contends, it’s not safe enough.

Thrombin-JMI, made by Bristol, TN-based King Pharmaceuticals (NYSE: [[ticker:KG]]), is derived from clotting proteins called thrombins in cow blood. Since that’s from a foreign source, the human immune system recognizes it as such, and can spark a reaction that can lead to severe bleeding and death, ZymoGenetics says. The company says it has found more than 25 published cases of patients who developed blood clotting disorders after they were given cow-derived thrombin products.

ZymoGenetics (NASDAQ: [[ticker:ZGEN]]) has a major dog in this fight, because its only marketed product—a genetically engineered copy of human thrombin—is a direct competitor to the King product. Both are approved by the FDA to control bleeding during surgery. Zymo won FDA approval to market its recombinant thrombin (Recothrom) in January 2008. Zymo has been arguing for years that its version of thrombin is less likely to spark an immune reaction than animal derived-ones, and that it’s therefore safer. But the argument hasn’t done much to sway doctors. The ZymoGenetics drug generated just $8.8 million in sales last year, and the company predicts it will generate $25 million to $35 million this year. Thrombin-JMI, the established player hospitals have used for years, had $255 million in sales a year ago.

Now, ZymoGenetics is clearly going on offense to get a bigger piece of the market. The drugs for bleeding products are used in an estimated 1 million surgeries a year in the U.S.

“Serious adverse events, including death, linked to bovine thrombin continue to be reported to the FDA,” said George Rodgers, a pathologist at the University of Utah, and medical director of the coagulation laboratory at Salt Lake City-based ARUP Laboratories, in a ZymoGenetics statement. “These adverse events are a serious, ongoing safety issue for patients undergoing surgery.”

ZymoGenetics CEO Doug Williams says the company remains committed to boosting sales of its drug in its second year on the market, as part of an overall strategy to reduce its cash spending rate and stabilize the company in a bad financing market. ZymoGenetics struggled in its first year to get hospitals to try the product, because many didn’t consider the bleeding drugs they use to be a problem, Zymo chairman Bruce Carter has said.

Via a citizen petition to the FDA, ZymoGenetics argues that the risks of treating people with the King product outweigh the benefits, and it should be pulled from the market. Physicians don’t have a readily available diagnostic test for when patients have developed antibodies to previous doses of the drug, and therefore don’t know when a follow-up treatment has the potential to cause a bleeding disorder, the company argues.

King Pharmaceuticals, when confronted in the past by ZymoGenetics’ arguments that its product isn’t safe enough, has generally dismissed them as exaggerations. I’ll add any comments here if the company responds to the latest salvo in the thrombin battle.

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.