Silence Therapeutics Announces Closing of Upsized Public Offering and Full Exercise of Underwriters’ Option to Purchase Additional ADSs

LONDON, August 14, 2026--Silence Therapeutics plc, (Nasdaq: SLN), ("Silence" or the "Company"), a global clinical-stage biotechnology company developing novel short interfering RNA ("siRNA") therapies, today announced the closing of its previously announced underwritten public offering of 14,907,407 American Depositary Shares ("ADSs"), each representing three ordinary shares of £0.05 each in the capital of the Company, in the United States at a public offering price of $13.50 per ADS, which includes the exercise in full by the underwriters of their option to purchase up to an additional 1,944,444 ADSs. The gross proceeds from the offering, before deducting underwriting discounts and commissions and other offering expenses, were approximately $201.3 million.

Jefferies, Morgan Stanley, Cantor and William Blair acted as joint book-running managers for the offering.

A shelf registration statement relating to the securities in the offering described above was filed with the U.S. Securities and Exchange Commission ("SEC") on May 18, 2026, and declared effective by the SEC on May 27, 2026. The offering was made by means of a prospectus supplement and the accompanying prospectus that form a part of the registration statement, as well as a related registration statement on Form S-3MEF. A final prospectus supplement and the accompanying prospectus relating to the offering has been filed with the SEC and is available on the SEC's website at www.sec.gov. Copies of the final prospectus relating to the offering may be obtained from: Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, New York, New York 10022, or by email at [email protected]; Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, NY 10014, or by email at [email protected]; Cantor Fitzgerald & Co., Attention: Capital Markets, 110 East 59th Street, 6th Floor, New York, NY 10022, or by email at [email protected]; or William Blair & Company, L.L.C., Attention: Prospectus Department, 150 North Riverside Plaza, Chicago, IL 60606, by telephone at (800) 621-0687, or by email at [email protected].

This press release shall not constitute an offer to sell or a 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 before registration or qualification under the securities laws of any such state or jurisdiction.