Tetraphase Pharmaceuticals Files Registration Statement for Proposed Initial Public Offering

Tetraphase Pharmaceuticals Files Registration Statement for Proposed Initial Public Offering

February 12, 2013

Watertown, MA – February 12, 2013 – Tetraphase Pharmaceuticals, Inc., today announced that it has filed a registration statement on Form S-1 with the U.S. Securities and Exchange Commission (SEC) relating to a proposed initial public offering.

Barclays and BMO Capital Markets are acting as joint book-running managers. Stifel, JMP Securities and Needham & Company are acting as co-managers for the offering. The offering will be made only by means of a prospectus. When available, copies of the preliminary prospectus relating to the offering may be obtained from: Barclays Capital Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, by calling (888) 603-5847, or by emailing barclaysprospectus@broadridge.com.

A registration statement relating to these securities has been filed with the SEC, but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This press release shall not constitute an offer to sell or a solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Tetraphase Pharmaceuticals, Inc.
Tetraphase Pharmaceuticals is a clinical stage biopharmaceutical company utilizing its breakthrough synthetic chemistry technology platform to discover and develop next-generation tetracycline antibiotics that address unmet needs such as the treatment of serious drug-resistant and gram-negative infections. The company has developed an emerging pipeline of potent novel antibiotics that provide a portfolio of intravenous and oral drug candidates with the potential to treat a wide range of infections, including broad-spectrum and selective-spectrum infections. To learn more about Tetraphase, please visit www.tphase.com.

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Contact:

David Lubner
Senior Vice President & CFO
Tetraphase Pharmaceuticals
Ph: 617-715-3551
Email: dlubner@tphase.com

Mike Beyer
Sam Brown Inc.
Phone: (773) 463-4211
Email: beyer@sambrown.com