Silence Therapeutics launches $150M ADS offering to fund pipeline

What happened

Silence Therapeutics plc, a biotechnology company developing RNA interference (RNAi) therapeutics, filed a preliminary prospectus supplement on August 10, 2026, for an offering of $150,000,000 in American Depositary Shares (ADSs). Each ADS represents three ordinary shares of the company, which is listed on the Nasdaq Global Market under the symbol "SLN."

The company stated the ADSs are being offered via a shelf registration process, with Jefferies, Morgan Stanley, Cantor, and William Blair acting as joint bookrunners. The underwriters have a 30-day option to purchase additional ADSs at the offering price less discounts and commissions.

The stock closed at $13.58 on the filing date, down 7.74% from the previous close of $14.72. The filing notes that on August 7, 2026, the closing price was $11.95 per ADS.

The filing also disclosed positive topline results from the Phase 2 SANRECO trial evaluating divesiran in patients with polycythemia vera (PV). The primary endpoint was met, with 88% of divesiran-treated patients achieving a clinical response versus 19% for placebo (p<0.0001). The company expects to initiate a Phase 3 trial in the first half of 2027.

The filing

The document is a Form 424B5, which is a prospectus supplement filed under Rule 424(b)(5) of the Securities Act. It is used to provide additional information about a specific offering of securities.

This offering is a "shelf takedown," meaning the company had previously filed a shelf registration statement (File No. 333-295992) that the SEC declared effective, allowing the company to sell securities in one or more offerings over time. This supplement details the terms of this particular offering.

The form is preliminary, marked "SUBJECT TO COMPLETION," so final pricing details (public offering price per ADS, underwriting commissions, and proceeds) are left blank in the filing. The company expects to deliver the ADSs to purchasers on or about August 2026.

What this means

Silence Therapeutics is raising capital by selling new shares. An ADS is a U.S. dollar-denominated security that represents shares of a foreign company; here, each ADS represents three ordinary shares of Silence Therapeutics plc, a UK company. By selling new ADSs, the company is issuing new ordinary shares, which increases the total share count and can dilute existing shareholders — likely contributing to the stock's drop on the day.

The company is a "smaller reporting company," so it follows reduced disclosure requirements. It focuses on siRNA molecules that silence specific genes, using its mRNAi GOLD platform to target liver diseases.

The proceeds will fund the company's operations, including the planned Phase 3 trial of divesiran for polycythemia vera, a condition where the body makes too many red blood cells. The Phase 2 results are a key part of the offering's narrative, as positive data supports the company's pipeline.

Normally, after a 424B5 filing with preliminary terms, the company completes pricing, then files a final prospectus supplement. The offering is expected to close about a week after the filing date. Investors should watch for the final price and the underwriters' exercise of the option for additional ADSs.