Lexington, Mass., February 19, 2009 – GI Dynamics today announced that it has closed an additional $15 million in Series C financing. With this additional funding, GI Dynamics has closed a total of $45 million in Series C financing, bringing the total raised by GI Dynamics since its inception to $61 million. Proceeds from this financing will be used to continue to advance the clinical development of the company’s EndoBarrier™ Gastrointestinal Liner and EndoBarrier platform of innovative medical devices for the treatment of metabolic disorders, including type 2 diabetes and obesity. To date, the EndoBarrier Gastrointestinal Liner has been studied in more than 175 patients demonstrating promising efficacy and safety data in both obese subjects and patients with type 2 diabetes.

Participants in the round included all of GI Dynamics’ current institutional investors: Advanced Technology Ventures; Catalyst Health Ventures, Cutlass Capital; Domain Associates, LLC; Johnson & Johnson Development Corporation; and Polaris Venture Partners.

“Attracting additional capital from leading investors and pharmaceutical organizations in this market is a testament to the progress we have made over the last several years and the significant commercial potential of our EndoBarrier™ Gastrointestinal Liner to treat metabolic disorders,” said Stuart A. Randle, chief executive officer of GI Dynamics. “This funding further strengthens our ability to aggressively advance EndoBarrier into the next stage of clinical trials for the treatment of type 2 diabetes and obesity, while continuing to develop additional products for the treatment of metabolic disorders based on the EndoBarrier intellectual property.”

About the EndoBarrier Gastrointestinal Liner

GI Dynamics is developing the EndoBarrier Gastrointestinal Liner, a noninvasive, removable device, which is considered investigational and not commercially available outside of the European Community. The EndoBarrier is being studied in clinical trials around the world as a potential short-term treatment for obesity and type 2 diabetes. The EndoBarrier creates a physical barrier between ingested food and the intestinal wall, which physicians believe, may change the metabolic pathway by controlling how food moves through the digestive system. This mechanical bypass of the small intestine is thought to mimic the effects of gastric bypass surgery on a patient’s metabolism, potentially resulting in weight loss and remission of type 2 diabetes. The EndoBarrier can be implanted and removed endoscopically (via the mouth) with relative ease and without the need for surgical intervention or alteration of the patient’s anatomy.

About GI Dynamics

GI Dynamics, a clinical-stage medical device company, is pioneering the development of new, noninvasive approaches to treat obesity, type 2 diabetes and related metabolic diseases. The company’s patented EndoBarrier™ technology has the potential to deliver immediate metabolic control by modifying metabolic pathways. GI Dynamics is developing the EndoBarrier™ Gastrointestinal Liner, an orally delivered, removable device that lines a portion of the small intestine, potentially resulting in short-term weight loss and improved glycemic control. Early clinical data have shown that the EndoBarrier provides short-term weight loss and immediate resolution of type 2 diabetes. Additional clinical trials are ongoing to validate the results seen in prior clinical studies and to evaluate longer-term clinical benefits of EndoBarrier for obesity and type 2 diabetes. Based in Lexington, Massachusetts and founded in 2003, GI Dynamics is backed by top-tier investors including Advanced Technology Ventures, Catalyst Health Ventures, Cutlass Capital, Domain Associates, Johnson & Johnson Development Corporation, and Polaris Venture Partners. For more information, visit GI Dynamics online at www.gidynamics.com.