WYETH PHARMACEUTICALS and CATALYST BIOSCIENCES announce agreement to develop and commercialize factor VIIa products

Multi-Product Collaboration Valued Potentially at More Than $500 Million

Collegeville, PA and South San Francisco, CA.- Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE) and Catalyst Biosciences, Inc. today announced that the two companies have formed an exclusive worldwide collaboration for the discovery, development and commercialization of Factor VIIa products to treat hemophilia and other bleeding conditions. Total payments under the collaboration, including an upfront payment of $21 million, research funding and milestone payments, could exceed $500 million, exclusive of royalty payments.

Through the collaboration, Wyeth will support the discovery, research and preclinical development by Catalyst of Factor VIIa products, including CB 813, Catalyst’s investigational candidate drug for the treatment and prophylaxis of acute bleeding in patients with hemophilia. The term of the exclusive research portion of the collaboration is two years, and may be extended by Wyeth for up to three additional years. During the research term of the agreement, Catalyst will receive support for up to twelve full-time employees. Wyeth will be responsible for the development, manufacturing and worldwide commercialization of products resulting from the collaboration. In addition, during the research term, Wyeth would have the right of first negotiation for any additional clotting factors discovered by Catalyst to treat hemophilia and other bleeding conditions.

Catalyst anticipates it would earn payments of up to $40 million or more over the next two years, including the upfront payment, committed research funding and preclinical and clinical milestone payments. In addition, Catalyst will be eligible to receive escalating clinical development and commercialization milestones, plus tiered double-digit royalties on sales of products resulting from the collaboration.

“This collaboration serves as an excellent fit with our recombinant Factor VIII and Factor IX hemophilia products and provides us with an opportunity to expand Wyeth’s hemophilia franchise,” says Mikael Dolsten, M.D., Ph.D., President, Wyeth Research. “We have been impressed by the caliber of Catalyst’s therapeutic protein engineering skills used in the Factor VIIa program and the lead candidate CB 813. We look forward to a highly productive collaboration.”

“We are thrilled to join forces with Wyeth, a biopharmaceutical company at the forefront of both hemophilia treatment and the development and commercialization of biologic therapies,” says Nassim Usman, Ph.D., Chief Executive Officer of Catalyst Biosciences. “This collaboration highlights the value Catalyst has created in our Factor VIIa portfolio of products. Revenues generated from research collaborations such as this one allow us to continually expand and support existing discovery efforts around bleeding disorder product candidates and the engineering of new Alterase therapeutic products.”