SAN DIEGO, California — AnaptysBio, Inc., a biotechnology company developing first-in-class antibody product candidates focused on unmet medical needs in inflammation and immuno-oncology, today announced the filing of a registration statement on Form S-1 with the U.S. Securities and Exchange Commission (SEC) relating to a proposed initial public offering of its common stock. All shares of common stock to be sold in the offering will be offered by AnaptysBio. The number of shares to be offered and the price range for the offering have not yet been determined. AnaptysBio intends to list its common stock on the NASDAQ Global Market under the ticker symbol “ANAB.”

BMO Capital Markets and Stifel are acting as joint book-running managers for the proposed offering. JMP Securities and Wedbush PacGrow are acting as co-managers.

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 by contacting BMO Capital Markets Corp., 3 Times Square, 25th Floor, New York, NY 10036, Attention: Equity Syndicate Department, or by telephone at (800) 414-3627, or by email at bmoprospectus@bmo.com; or Stifel, Nicolaus & Company, Incorporated, Attention: Syndicate, One Montgomery Street, Suite 3700, San Francisco, CA 94104, or by telephone at (415) 364-2720, or by email at syndicateops@stifel.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 these securities, 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.