Summit Therapeutics Announces Proposed Public Offering of Common Stock

Summit Therapeutics Announces Proposed Public Offering of Common Stock

Summit Therapeutics Inc. (Nasdaq: SMMT) (“Summit,” “we,” or the “Company”) today announced that it has commenced an underwritten public offering of $500.0 million of shares of its common stock. All of the shares in the proposed offering are being offered by Summit. In addition, Summit intends to grant the underwriters a 30-day option to purchase up to an additional $75.0 million of shares of its common stock at the public offering price, less underwriting discounts and commissions. The proposed offering is subject to market and other 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.

Summit intends to use the net proceeds from the proposed offering, together with its existing cash, cash equivalents, to fund the research and development of its lead product candidate, ivonescimab, and for working capital and other general corporate purposes.

J.P. Morgan, Goldman Sachs & Co. LLC and Citigroup are acting as joint book-running managers for the proposed offering.

The securities described above are being offered by Summit pursuant to a shelf registration statement on Form S-3, including a base prospectus, that was previously filed with the Securities and Exchange Commission (SEC) and which became automatically effective on June 9, 2026. A preliminary prospectus supplement and accompanying base prospectus relating to and describing the terms of the proposed offering will be filed with the SEC and will be available on the SEC’s website at www.sec.gov. Copies of the preliminary prospectus supplement and accompanying base prospectus may also be obtained, when available, from: J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by email at prospectus-eq_fi@jpmchase.com and postsalemanualrequests@broadridge.com; Goldman Sachs & Co. LLC, Attention: Prospectus Department, 200 West Street, New York, NY 10282, by telephone at (866) 471-2526, or by email at Prospectus-ny@ny.email.gs.com; or Citigroup, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at (800) 831-9146.