Singapore, Sep 8, 2010: Bristol-Myers Squibb is acquiring ZymoGenetics, for $9.75 per share in cash. The transaction, with an aggregate purchase price of approximately $885 million, or approximately $735 million net of cash acquired, has been unanimously approved by the boards of directors of both companies.

The board of directors of ZymoGenetics intends to recommend that ZymoGenetics’ shareholders tender their shares in the offer. In addition, shareholders holding approximately 37 percent of the outstanding shares of ZymoGenetics’ common stock have entered into agreements with Bristol-Myers Squibb to support the transaction and to tender their shares in the offer.

“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 Mr Lamberto Andreotti, CEO, Bristol-Myers Squibb. “In addition, ZymoGenetics brings proven capabilities with therapeutic proteins and revenue from a marketed specialty surgical biologic. This acquisition is another example of our strategic, targeted approach to business development.”

“By joining forces with Bristol-Myers Squibb, we believe we will enhance the long-term potential of ZymoGenetics’ portfolio of assets, while providing a compelling valuation for our shareholders,” said Dr Douglas E Williams, CEO of ZymoGenetics. “Our collaboration with Bristol-Myers Squibb in the development of PEG-Interferon lambda has been extremely positive and it has given us an opportunity to fully appreciate their capabilities.

Bristol-Myers Squibb gains the following as a result of the acquisition:

• Full ownership of pegylated-interferon lambda, a novel interferon in phase IIb development for the treatment of Hepatitis C infection. The companies have collaborated on the development of pegylated-interferon lambda since January 2009.

• Recothrom, a recombinant thrombin approved by the US Food and Drug Administration(FDA) for use as a topical hemostat to control non-arterial bleeding during surgical procedures.

• IL-21 protein, a cytokine currently being tested in an open-label, phase II clinical study as a potential immunotherapy treatment for metastatic melanoma.

• An earlier-stage pipeline of six biologic drug candidates, including an anti-IL-31 antibody, currently in pre-clinical development for atopic dermatitis.

• Potential milestone and royalty payments from six partnered programs in various stages of clinical development by EMD Serono and Novo Nordisk.

Initially, the transaction is expected to be modestly dilutive to earnings per share (EPS) for Bristol-Myers Squibb. In 2010, the transaction is expected to be dilutive to EPS by approximately $0.03. In 2011, the transaction is expected to be dilutive to EPS by approximately $0.07.

Under the terms of the definitive agreement, Bristol-Myers Squibb will commence a cash tender offer on or about September 9, 2010 to purchase all of the outstanding shares of ZymoGenetics’ common stock for $9.75 per share. The closing of the tender offer is subject to tender of a number of shares which is equal to or greater than 48,282,192 shares, which represents approximately 56 percent of the outstanding shares as of August 31, 2010.