Tetraphase Pharmaceuticals Completes Series A Financing to Support the Advancement of Breakthrough Synthetic Chemistry Platform

Tetraphase Pharmaceuticals, Inc.

Tetraphase Pharmaceuticals Completes Series A Financing to Support the Advancement of Breakthrough Synthetic Chemistry Platform

August 6, 2008

Raises $15M to Close Second Tranche of $25M Financing

WATERTOWN, Mass., Aug 06, 2008 (BUSINESS WIRE) -- Tetraphase Pharmaceuticals Inc. announced today that it has closed the second tranche of its $25 million Series A financing to support the advancement of several novel and potent antibiotic drug candidates. This second tranche of $15 million was funded by existing investors - Mediphase Venture Partners, CMEA Ventures, Fidelity Biosciences, Flagship Ventures and Skyline Ventures.

Tetraphase Pharmaceuticals was established in August 2006 to advance and commercialize the ground-breaking synthetic chemistry platform developed by internationally recognized chemist, Dr. Andrew Myers of Harvard University. This proprietary platform overcomes a key barrier to discovering unprecedented classes of antibiotics and other drugs by enabling for the first time their total synthesis from basic building blocks. The initial focus of the company is on the discovery of novel antibiotics to treat drug-resistant infections.

"Since our inception, we have made significant progress, applying our unique technology to the development of several novel and potent antibiotic drug candidates," said Guy Macdonald, President and Chief Executive Officer. "We are very pleased that our investors share our enthusiasm for and confidence in our programs."

About Tetraphase Pharmaceuticals Inc.

Tetraphase Pharmaceuticals is capitalizing on breakthrough synthetic chemistry technology for drug discovery and development based on a process developed by world leading organic chemist Dr. Andrew Myers of Harvard University. This enabling advance in chemistry provides the company with a broad-range of commercial opportunities across a number of significant disease categories.

Contact:

Tetraphase Pharmaceuticals Inc.
David Lubner, 617-715-3551
Sr. Vice President and Chief Operating Officer