Intellectual property covering compounds that have utility in treating SMA licensed

Repligen Corporation (Nasdaq: RGEN) announced today that it has entered into an exclusive license agreement with Families of Spinal Muscular Atrophy (FSMA) for intellectual property covering compounds which may have utility in treating Spinal Muscular Atrophy (SMA). SMA is an inherited neurodegenerative disease in which a defect in the SMN1 ("survival motor neuron") gene results in low levels of the protein SMN and leads to progressive damage to motor neurons, loss of muscle function and, in many patients, early death. The licensed compounds increase the production of SMN in cells derived from patients. Further testing of these compounds in two transgenic mouse models of SMA demonstrated significantly increased survival suggesting potential clinical utility. There is currently no treatment or cure for SMA.

"Families of SMA has made remarkable progress in defining a series of highly potent compounds which may be clinical candidates for SMA," stated Walter C. Herlihy, President and Chief Executive Officer of Repligen Corporation. "We look forward to working with FSMA and their collaborators in the development of what we hope will be an important new treatment for SMA."

"At this point in the program, joining forces with a corporate partner to advance into clinical studies is the best way to meet our objective of accelerating drug development for SMA," stated Kenneth Hobby, President of Families of SMA. "We view Repligen as an ideal partner for this program with the necessary resources and expertise to invest in and focus on successfully developing an effective treatment for our patients."

Patients lacking a functional SMN1 gene survive only because humans carry a second gene, known as SMN2, which produces an identical protein but at much lower levels. Genetic analysis of SMA patients has revealed a striking correlation between disease severity and the number of copies of SMN2 carried by the patient. Patients with 2 copies of the SMN2 gene are usually unable to ever sit without assistance while patients with 4 copies develop few symptoms before adulthood. Thus, a doubling of the SMN2 gene copy number dramatically alters disease course and suggests that a therapy which increases the level of SMN protein in motor neurons may provide a significant clinical benefit. Symptoms of SMA typically emerge before the age of 2 and often progress to severe physical disability or loss of life. SMA is diagnosed in approximately one in every 6,000 births in the United States and Europe where the estimated prevalence is approximately 20,000 patients.

Conference Call Friday, October 23, 2009

Repligen will host a conference call and webcast on Friday, October 23, 2009 at 8:30 a.m. EDT to provide an update on this corporate development. Walter Herlihy, President and CEO of Repligen will be joined on the call by Kenneth Hobby, President of FSMA, Dr. Jill Jarecki, Research Director of FSMA and Dr. Kathryn Swoboda, University of Utah School of Medicine who cares for SMA patients.