Press Release February 27, 2007

Adnexus Therapeutics and Bristol-Myers Squibb Company Announce Collaboration to Develop and Commercialize Innovative Oncology Compounds

Feb. 27, 2007 — Adnexus™ Therapeutics and Bristol-Myers Squibb Company (NYSE: BMY) have announced a worldwide strategic alliance to discover, develop and commercialize Adnectin-based therapeutics for important oncology-related targets.

Under the collaboration, Adnexus will deploy its PROfusion technology on up to six research programs to identify and deliver pre-clinical Adnectin candidates to Bristol-Myers Squibb. Bristol-Myers Squibb will be responsible for global development and commercialization activities, with Adnexus retaining a limited co-promotion right to the first product to achieve regulatory approval in the United States.

Under the terms of the agreement, Bristol-Myers Squibb will provide committed funds of approximately $30 million over the next three years to Adnexus, consisting of upfront and guaranteed research payments. Adnexus also is eligible to receive regulatory milestone payments of up to $210 million per product, as well as royalties on product sales and sales-based milestone payments.

Goodwin Procter attorneys Kingsley Taft and Shaun Ryan represented Adnexus Therapeutics in this deal.