ROCKVILLE, Md.--(BUSINESS WIRE)--Emergent BioSolutions Inc. (NYSE:EBS) announced today that it has submitted to the U.S. Food and Drug Administration (FDA) a Development Plan for the company’s Recombinant Protective Antigen (rPA) anthrax vaccine candidate. Emergent submitted the Development Plan ahead of the June 15 deadline in response to the Department of Health and Human Services’ (HHS) amendment to its request for proposal to develop and deliver up to 25 million doses of an rPA vaccine for the Strategic National Stockpile. The amendment requested that all bidders deemed to be in the competitive range submit to FDA a comprehensive plan outlining the regulatory strategy for their rPA vaccine.