X0303 4 2010-04-28 0 0001367644 Emergent BioSolutions Inc. EBS 0001380185 El-Hibri Fuad 2273 RESEARCH BLVD., SUITE 400 ROCKVILLE MD 20850 1 1 1 0 CEO and Chairman Common Stock 2010-04-28 4 S 0 1700 16.50 D 1572455 I By Biovac, L.L.C. Common Stock 2010-04-29 4 S 0 23300 16.5315 D 1549155 I By Biovac, L.L.C. Common Stock 874320 D Common Stock 6643794 I By Intervac, L.L.C. Common Stock 5011 I By Karim El-Hibri Trust Common Stock 5011 I By Yusra El-Hibri Trust Common Stock 5011 I By Faiza El-Hibri Trust Common Stock 2965043 I By BioPharm, L.L.C. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by Biovac L.L.C. on March 9, 2010. Biovac, L.L.C. was the direct owner of the shares of Common Stock sold pursuant to the Rule 10b5-1 trading plan, and was or is the direct owner of the shares of Common Stock reported as beneficially owned immediately following each of the reported sales. Both before and after the reported sales, Mr. El-Hibri held individually and with his wife, as tenants by the entirety, an aggregate 89.2% equity interest in Biovac, L.L.C. Biovac, L.L.C. is the direct owner of 1,549,155 shares of Common Stock. Mr. El-Hibri disclaims beneficial ownership of the shares of Common Stock directly owned by Biovac, L.L.C. for purposes of Section 16, except to the extent of his pecuniary interest in 1,381,846 shares. The sales price for the transaction on April 29, 2010 is the weighted average sales price for the transactions. The prices range from $16.5 to $16.595. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Includes restricted stock units granted under the Amended and Restated Emergent BioSolutions Inc. 2006 Stock Incentive Plan that vest in three equal annual installments beginning March 9, 2011. Mr. El-Hibri holds with his wife, as tenants by the entirety, an aggregate 41.1072% equity interest in Intervac, L.L.C. Mr. El-Hibri disclaims beneficial ownership of the shares of Common Stock directly owned by Intervac, L.L.C. for purposes of Section 16, except to the extent of his pecuniary interest therein in 2,731,079 shares. These shares are held in a trust for the benefit of a child of the reporting person. The reporting person is trustee of this trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. Mr. El-Hibri is the holder of a 40.17% (567,582.3 units) equity interest in BioPharm, L.L.C. BioPharm, L.L.C. is the direct owner of 2,965,043 shares of Common Stock. Mr. El-Hibri disclaims beneficial ownership of these shares for purposes of Section 16, except to the extent of his pecuniary interest in 1,191,058 shares. /s/ Carl A. Valenstein, attorney-in-fact 2010-04-29