Emergent BioSolutions Inc. (NYSE: EBS) announced today the initiation of a Phase 1b study (Protocol 16009) of TRU-016 in combination with rituximab for patients with previously untreated chronic lymphocytic leukemia (CLL). TRU-016 is a humanized anti-CD37 mono-specific protein therapeutic in development for the treatment of B-cell malignancies. “Preclinical studies have shown increased anti-tumor activity for the combination of TRU-016 and rituximab beyond the levels achieved when either drug was administered alone,” said Scott C. Stromatt, M.D., Senior Vice President and Chief Medical Officer, Emergent BioSolutions. “We look forward to clinical evaluation of the effect of TRU-016 in combination with rituximab in previously untreated CLL patients.” The Phase 1b, single-arm, open label study is enrolling approximately 24 previously untreated CLL patients and will evaluate the safety and efficacy of TRU-016 (an anti-CD37 biologic) in combination with rituximab (an anti-CD20 biologic). The primary outcome measurement for this study is overall response rate. Patients will receive TRU-016 and rituximab intravenously for six months. The company expects to complete enrollment in this study in 2013 and present data in the second half of 2013. TRU-016 is also being evaluated in an ongoing Phase 2 study (protocol 16201) in combination with bendamustine for patients with relapsed CLL. This study is designed to evaluate the safety and efficacy of TRU-016 in combination with bendamustine compared with bendamustine alone. The primary endpoint for the Phase 2 study is an overall response rate as defined by 2008 International Workshop on Chronic Lymphocytic Leukemia (IWCLL) criteria. Secondary endpoints include complete and partial response rates as defined by the 1996 National Cancer Institute (NCI) criteria, progression-free survival, duration of response, and improvement in quality of life and disease symptoms. The company expects to complete enrollment in this study by the end of 2012 and present data in the second half of 2013. Additional information about the Phase 1b study, as well as the ongoing Phase 2 study in combination with bendamustine in relapsed CLL, can be found on www.clinicaltrials.gov. About Emergent BioSolutions Emergent BioSolutions protects and enhances life by developing and manufacturing vaccines and therapeutics that are supplied to healthcare providers and purchasers for use in preventing and treating disease. Emergent’s marketed and investigational products target infectious diseases, oncology and autoimmune disorders. Additional information about the company may be found at www.emergentbiosolutions.com. Follow us on twitter @emergentbiosolu. Safe Harbor Statement This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Any statements, other than statements of historical fact, including statements regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management, including any potential future securities offering, our expected revenue growth and net earnings for 2012, and any other statements containing the words “believes”, “expects”, “anticipates”, “plans”, “estimates” and similar expressions, are forward-looking statements. There are a number of important factors that could cause the company’s actual results to differ materially from those indicated by such forward-looking statements, including the success of our ongoing and planned preclinical studies and clinical trials; the rate and degree of market acceptance and clinical utility of our products; the success of our ongoing and planned development programs; the timing of and our ability to obtain and maintain regulatory approvals for our other product candidates; our commercialization, marketing and manufacturing capabilities and strategy; our estimates regarding expenses, future revenue, capital requirements and needs for additional financing; and other factors identified in the company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2012 and subsequent reports filed with the SEC. The company disclaims any intention or obligation to update any forward-looking statements as a result of developments occurring after the date of this press release.