ZymoGenetics seeks OK to market drug

ZymoGenetics has submitted an application to the U.S. Food and Drug Administration for permission to market its first commercial drug in the United States.

The Seattle biotech company is asking the FDA to approve Thrombin, a genetically engineered copy of a human protein, which surgeons can use to control surgical bleeding. The filing was made on schedule by the end of the year and means the drug could be approved in the U.S. market after a customary 10-month FDA review.

The company reported in September that Thrombin demonstrated safety and effectiveness in a clinical trial of 411 patients.

In the study, half of patients got Thrombin, and half got the standard drug derived from cow blood. The study showed Thrombin was roughly equally effective, but safer.

About 1.5 percent of Thrombin patients developed antibody reactions against the drug, compared with 22 percent who had a similar reaction to the other drug.

Approval expected

Analysts are confident it will win approval. The safety advantage is meaningful, because such reactions can cause severe bleeding and prevent patients from being re-dosed with Thrombin during surgery.

"This is our first home-grown product taken through clinical trials and filed with the agency," said Doug Williams, ZymoGenetics' chief scientific officer. "It's the culmination of five years of work. It's a big milestone."

The potential market for such a product is unclear. The existing drug, King Pharmaceuticals' Thombin-JMI, is expected to reach $250 million in sales this year and be used in about 1 million surgeries in the U.S.

ZymoGenetics says it will make cow-derived Thrombin obsolete, and possibly double or even triple the size of the market. It says there are limited supplies of King's drug, and it carries warning labels that may discourage surgeons from using it.

Because of Thrombin's comparative safety, the company is confident it will be able to market the product more broadly.

The ZymoGenetics drug, manufactured under contract by Abbott Laboratories, will also not be limited by manufacturing capacity, Williams said.

Over the next six months, Williams said, the company will continue seeking a European partner that can help Thrombin win approval to market the drug in Europe.

ZymoGenetics has not had discussions yet with European authorities about the drug, but it hopes to submit the same clinical data and also win approval there relatively quickly.

ZymoGenetics does have competition in its bid to replace cow-derived Thrombin. Omrix Biopharmaceuticals, based in New York, has a drug derived from human blood. The company sent in its application six weeks ahead of ZymoGenetics, and is racing it to the market.

Williams said his company doesn't fear the marketplace. He said Omrix will be able to supply only about 10 to 20 percent of the market.

500 employees

ZymoGenetics has about 500 employees in Seattle. It plans to hire a 50-person sales force to market Thrombin late next year, and grow to a total 600 employees nationwide next year.

It has two other drugs in clinical trials — atacicept for autoimmune diseases and IL-21 for cancer. It is also preparing to push another drug, IL-29 for Hepatitis C, into clinical trials.

Luke Timmerman: 206-515-5644 or ltimmerman@seattletimes.com