Archemix Announces Collaboration with Pfizer to Discover Aptamer Therapeutics

CAMBRIDGE, MA
January 9, 2007

Archemix Corp. today announced that it has signed an agreement with Pfizer focused on the discovery of first-in-class aptamers for the development and commercialization as therapeutics.

As part of the collaboration, Archemix will use its proprietary SELEX technology to discover and generate product candidates to three disease-associated targets identified by Pfizer. Pfizer will be responsible for developing and commercializing the resulting product candidates.

Under the terms of the agreement, Archemix will receive an upfront cash payment as well as research funding and development milestones. Archemix is also entitled to receive a royalty on any marketed products developed under the collaboration. Detailed financial terms were not disclosed.

"We believe that the combination of Archemix's aptamer approach and Pfizer's drug development capabilities will allow therapeutic aptamers to be advanced rapidly," said Dr. Errol De Souza, President and Chief Executive Officer of Archemix. "We have now completed three major partnerships in the last six months, and our collaboration with Pfizer is another example of the value of our aptamer technology and reflects the growing enthusiasm for the potential of aptamer therapeutics."

About Aptamers
Aptamers are single-stranded nucleic acids that form well-defined three dimensional shapes, allowing them to bind target molecules in a manner that is conceptually similar to antibodies. Aptamers combine the optimal characteristics of small molecules and antibodies, including high specificity and affinity, chemical stability, low immunogenicity, and the ability to target protein-protein interactions. In contrast to monoclonal antibodies, aptamers are chemically synthesized rather than biologically expressed, may offer a significant cost advantage.

About Archemix
Archemix Corp. is a privately-held biopharmaceutical company based in Cambridge, Massachusetts. The company's mission is to develop aptamers as a class of directed therapeutics for the prevention and treatment of human disease. Because of their unique properties and proven efficacy, aptamers offer an alternative to biologics and small molecules in numerous applications and offer the potential to be a major class of drugs for the treatment of unmet medical needs.

Archemix's aptamer expertise is complemented by a robust patent estate comprised of over 220 issued and 230 pending patents covering the identification, composition, and use of therapeutic aptamers. In addition to the company's core aptamer generation technology, Archemix possesses strong expertise in both pre-clinical and clinical drug development.

Further information on Archemix can be found at www.archemix.com.

For more information about Archemix or aptamers, or to speak with Dr. De Souza, please contact Davia Temin of Temin and Company at 212-588-8788 or news@teminandco.com.