Big breaking news just hit the Seattle biotech community. Seattle-based ZymoGenetics (Nasdaq: ZGEN), a pioneer in the Northwest life sciences cluster that was founded back in 1981, has agreed to be acquired by pharmaceutical giant Bristol-Myers Squibb (NYSE: BMY) for $885 million.

The deal, approved by the boards of both companies, values ZymoGenetics at $9.75 per share -- a whopping 84% premium over Zymo's closing share price of $5.30 at today's market close.

These two companies have gotten to know each other quite well since January 2009, when Bristol agreed to pay as much as $1.1 billion for the right to co-develop and co-market a drug for hepatitis C that was designed to have the anti-viral killing punch of an existing drug without causing nasty flu-like side effects. That drug, pegylated interferon lambda, has shown promising results in early-phase trials, and the two companies are expected to release data from a larger study later this fall. The takeover means that Bristol will get full ownership of the drug, as well as ZymoGenetics' marketed treatment for surgical bleeding, and other drug candidates for autoimmune diseases and cancer in its pipeline.

"The acquisition of ZymoGenetics brings us full ownership of a promising investigational biologic that strengthens our very diversified Hepatitis C portfolio. Building on our leadership in virology, we are developing a strong portfolio to help patients with Hepatitis C," said Lamberto Andreotti, chief executive officer of Bristol-Myers Squibb.

The deal is expected to drag down Bristol's profits by 3 cents a share this year, and by about 7 cents a share in 2011.

Today's statement doesn't say what will happen to the ZymoGenetics workforce in Seattle. The company has gone through a couple recent rounds of layoffs, but still had 323 employees at the end as of Dec. 31, 2009, according to its most recent annual report. We'll update this space when we know more about the deal and its local impact.

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Luke Timmerman is the National Biotech Editor of Xconomy, and the Editor of Xconomy Seattle. You can e-mail him at [email protected], or follow him at twitter.com/ldtimmerman.