NEW HAVEN, Conn., Feb. 20, 2013 (GLOBE NEWSWIRE) -- Achillion Pharmaceuticals, Inc. (Nasdaq:ACHN) announced today that it has commenced an underwritten public offering of $125 million of its common stock. In connection with this offering, Achillion plans to grant the underwriters a 30-day option to purchase additional shares of its common stock. Citigroup and Leerink Swann LLC are acting as joint book-running managers for the offering. The offering is subject to market conditions, and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering. The offering is being made by Achillion pursuant to a shelf registration statement on Form S-3 previously filed with the Securities and Exchange Commission (SEC), which the SEC declared effective on November 21, 2012. A preliminary prospectus supplement related to the offering will be filed with the SEC and will be available on the SEC's website located at http://www.sec.gov. Copies of the preliminary prospectus supplement and accompanying prospectus relating to this offering may be obtained from Citigroup, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, via telephone at 1-800-831-9146 or email at firstname.lastname@example.org or from Leerink Swann LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA 02110, via telephone number (800) 808-7525, Ext. 4814, or email at email@example.com. This press release shall not constitute an offer to sell, or the solicitation of an offer to buy, nor will there be any sale of, these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of such state or other jurisdiction. About Achillion Pharmaceuticals, Inc. Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease.