Repligen Initiates Phase 3 Clinical Trial of RG1068 for Pancreatic MRI Imaging

WALTHAM, MA - March 26, 2008 - Repligen Corporation (NASDAQ: RGEN) announced today that the Company has initiated a Phase 3 clinical trial to evaluate the use of RG1068, synthetic human secretin, to improve the assessment of pancreatic duct structures by magnetic resonance imaging (MRI). This Phase 3 study is a multi-center, baseline-controlled, single dose study in which approximately 250 patients will receive an unenhanced MRI followed by a secretin-enhanced MRI of the pancreas. This study is designed to assess the sensitivity and specificity of secretin-enhanced MRI to improve the ability to detect pancreatic duct abnormalities relative to MRI alone. Detailed visual assessment of the pancreatic ducts is important in the assessment, diagnosis and treatment of diseases such as acute and chronic pancreatitis. This study is being conducted at approximately 30 clinical sites within the United States and Canada.

"Based on discussions with the FDA, we believe a single positive Phase 3 clinical trial of similar design to our Phase 2 study will be sufficient for an NDA filing," stated Walter C. Herlihy, President and Chief Executive Officer of Repligen Corporation. "There are approximately 150,000 pancreatic MRI's conducted in the U.S. each year that could benefit from enhancement with secretin."

source: RepliGen Corporation