Arcus Biosciences, Inc. (NYSE:RCUS), a clinical-stage biopharmaceutical company focused on creating innovative cancer therapies, today announced that it has commenced an underwritten public offering of its common stock. The company intends to grant the underwriters a 30-day option to purchase up to an additional 15% of the shares of its common stock offered in the public offering. All of the shares in the offering will be sold by Arcus Biosciences. The offering is subject to market and other conditions, and there can be no assurances as to whether or when the offering may be completed, or as to the actual size or terms of the offering.

A shelf registration statement relating to the offered shares of common stock was filed with the Securities and Exchange Commission (SEC) and is effective. A preliminary prospectus supplement and accompanying prospectus relating to the offering will be filed with the SEC and will be available on the SEC's website, located at www.sec.gov. Copies of the prospectus related to the offering may be obtained, when available, from Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, or by telephone at (800) 831-9146; or SVB Leerink LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA 02110, by telephone at (800) 808-7525, ext. 6218, or by email at [email protected]; or Evercore Group L.L.C., Attention: Equity Capital Markets, 55 East 52nd Street, 35th Floor, New York, NY 10055, or by telephone at (888) 474-0200, or by email at [email protected].

This press release contains or may imply "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. For example, forward-looking statements include statements regarding the size and completion of the proposed public offering. These statements are subject to various risks and uncertainties, actual results could differ materially from those projected and Arcus Biosciences cautions investors not to place undue reliance on the forward-looking statements in this press release. These risks and uncertainties include, without limitation, risks and uncertainties related to market conditions and satisfaction of customary closing conditions related to the public offering. There can be no assurance that Arcus Biosciences will be able to complete the public offering on the anticipated terms, or at all. Risks and uncertainties relating to Arcus Biosciences and its business can be found under the heading "Risk Factors" in Arcus Biosciences' preliminary prospectus supplement related to the proposed offering filed or to be filed with the SEC on May 27, 2020, and under the caption "Risk Factors" in Arcus Biosciences' Quarterly Report on Form 10-Q filed with the SEC on May 5, 2020. Except as otherwise required by law, Arcus Biosciences disclaims any intention or obligation to update or revise any forward-looking statements, which speak only as of the date hereof, whether as a result of new information, future events or circumstances or otherwise.