Emergent BioSolutions Submits Proposal in Response to HHS RFP for Development and Procurement of a Recombinant Protective Antigen Anthrax Vaccine

Business Wire, July 31, 2008

The company's submission provides the U.S. Government with the critical option to select a domestic source to meet planned procurement of 25 million doses of rPA vaccine

ROCKVILLE, Md. -- Emergent BioSolutions Inc. (NYSE:EBS) announced today that it has submitted a proposal in response to a request for proposal (RFP) issued by the U.S. Department of Health and Human Services (HHS) for a recombinant protective antigen anthrax vaccine (rPA). Emergent's rPA vaccine candidate is a reformulated and more stable form of the rPA 102 vaccine originally developed at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and is well-positioned to be a leading candidate for an award under this RFP. One Phase II clinical trial of rPA 102 has been completed.

HHS's RFP is designed to meet the government's stated goal to procure 25 million doses of an rPA anthrax vaccine for the Strategic National Stockpile (SNS). In the event that Emergent receives an award under the rPA RFP, doses of rPA procured by HHS would be in addition to the 18.75 million doses of the company's FDA-licensed product, BioThrax[R] (Anthrax Vaccine Adsorbed), that HHS is procuring under the existing $448M contract with Emergent. HHS has indicated that any awards under the rPA RFP would be granted at the end of 2008, at the earliest.

"We are very pleased with our submission in response to this RFP, and we are confident that our rPA 102 vaccine is a leading candidate to be selected as an advanced rPA anthrax vaccine. Our company is proud of our proven track record of delivering critical biodefense countermeasures to the U.S. government, and we believe our reputation as the premiere domestic biodefense supplier, coupled with our development and manufacturing expertise, uniquely situates Emergent to meet HHS's stated commitment to procure 25 million doses of a recombinant anthrax vaccine for the Strategic National Stockpile," said Fuad El-Hibri, chairman and chief executive officer of Emergent BioSolutions.

"Considerable resources have been devoted to improving the stability of the rPA 102 vaccine. Analytical testing and non-clinical data indicate the changes made to the formulation of rPA 102 has significantly improved the stability of this vaccine candidate. We are confident that the formulation changes have addressed previous concerns regarding the stability of the product. We believe that the current formulation will meet the U.S. government's stability requirements for an rPA vaccine," said Dr. James Jackson, senior vice president and chief scientific officer of Emergent BioSolutions.

The company expects to manufacture this rPA anthrax vaccine, as well as BioThrax, in its recently constructed, large-scale manufacturing facility at its Lansing campus. The continued development of this rPA vaccine candidate further solidifies Emergent's franchise of anthrax countermeasures, which now includes:

BioThrax - the only FDA-approved vaccine to prevent the infection of anthrax. Nearly 2.0 million men and women of the United States military have received the vaccine, and HHS has procured more than 28 million doses of BioThrax for the SNS;

rPA 102 - a recombinant anthrax vaccine candidate, which is composed of a purified protein with an alum adjuvant and is designed to induce antibodies that neutralize anthrax toxins;

AVA7909 - an anthrax vaccine candidate composed of BioThrax[R] and the immunostimulatory oligodeoxynucleotide compound CPG 7909 (VaxImmune[R]) developed by Coley Pharmaceutical Group (purchased by Pfizer Inc. in 2007).;

AVP-21D9 - a human monoclonal antibody product candidate being developed as an intravenous post-exposure treatment for patients who present symptoms of anthrax disease; and

AIG - a polyclonal anthrax immune globulin product candidate being developed as an intravenous post-exposure treatment for patients who present symptoms of anthrax disease, is derived from human plasma from individuals who have been vaccinated with BioThrax.

About rPA 102

The vaccine candidate, rPA 102, is based on a recombinant form of the protective antigen protein. This vaccine contains a purified protein (rPA) formulated with an alum adjuvant and is designed to induce antibodies that neutralize anthrax toxins. The vaccine candidate does not cause anthrax infection and is based on the pioneering work of USAMRIID. rPA 102 has been the subject of two research and development grants totaling approximately $100 million from the National Institute for Allergy and Infectious Diseases (NIAID).

About Emergent BioSolutions Inc.

Emergent BioSolutions Inc. is a leading, multinational biopharmaceutical company dedicated to one simple mission -- to protect life. Emergent develops, manufactures and commercializes immunobiotics, consisting of vaccines and therapeutics that assist the body's immune system to prevent or treat disease. Emergent's products target infectious diseases and other medical conditions that have resulted in significant unmet or underserved public health needs. The company's marketed product, BioThrax[R] (Anthrax Vaccine Adsorbed), is the only vaccine approved by the U.S. Food and Drug Administration for the prevention of anthrax infection. www.emergentbiosolutions.com.