Tetraphase Pharmaceuticals Announces Closing Of Public Offering of Common Stock

Tetraphase Pharmaceuticals, Inc.

today announced the closing of its underwritten public offering of 4,542,500 shares of common stock at an offering price of $19.00 per share. The shares of common stock issued and sold in the offering at the closing include 592,500 shares issued upon the exercise in full by the underwriters of their option at the offering price. The gross proceeds to Tetraphase from this offering were $86.3 million, before deducting underwriting discounts and commissions and offering expenses payable by Tetraphase. BMO Capital Markets, Stifel and Guggenheim Securities are acting as joint bookrunning managers for the offering and JMP Securities and Needham & Company are acting as co-managers for the offering. A shelf registration statement relating to the shares of common stock offered in the public offering described above was filed with the Securities and Exchange Commission (SEC) on May 1, 2014 and declared effective by the SEC on May 21, 2014. The offering was made only by means of the written prospectus and prospectus supplement that form a part of the registration statement. A prospectus supplement related to the offering has been filed with the SEC and may be obtained for free by visiting EDGAR on the SEC website at www.sec.gov. Copies of the prospectus supplement and the accompanying prospectus relating to the securities offered may also be obtained by contacting BMO Capital Markets Corp. at 3 Times Square, 27th Floor, New York, NY 10036, Attention: Equity Syndicate Department, by telephone at (800) 414-3627 or by email to bmoprospectus@bmo.com or by contacting Stifel, Nicolaus & Company, Incorporated, Attention: Syndicate, One Montgomery Street, Suite 3700, San Francisco, California 94104, by telephone at (415) 364-2720 or by email to syndprospectus@stifel.com or by contacting Guggenheim Securities, LLC, 330 Madison Avenue, 8th Floor, New York, NY 10017, Attention: Equity Syndicate Department, by telephone at (212) 518-9349 or by email to GSEquityProspectusDelivery@guggenheimpartners.com. This press release shall not constitute an offer to sell or the solicitation of an offer to buy any of Tetraphase's securities. No offer, solicitation or sale will be made in any jurisdiction in which such offer, solicitation or sale is unlawful.