FRANKFURT: German drugmaker Merck KGaA said Monday it agreed to acquire London-based Silence Therapeutics in an all-cash deal valued at about $1.3 billion, adding an experimental treatment for a rare blood cancer and a platform for developing RNA-based medicines.

Merck will pay $20 per American depositary share, or $6.6667 per ordinary share. The price represents a 130% premium to Silence’s closing price on Friday and an 82% premium to its 30-day volume-weighted average price of $10.99. The transaction has an enterprise value of about $1.1 billion.

Why Merck is buying

The acquisition gives Merck access to Silence’s short interfering RNA, or siRNA, technology, which is designed to interrupt disease-related genetic messages before cells produce harmful proteins. Merck said the deal will strengthen its rare-disease pipeline and broaden its precision-medicine capabilities.

Silence’s lead candidate, divesiran, is a Phase 3-ready therapy for phlebotomy-dependent polycythemia vera, a rare blood cancer in which the bone marrow produces too many red blood cells. Patients often require repeated therapeutic blood draws to control red-blood-cell levels.

If approved, divesiran would compete with Mimrylo, a treatment developed by Takeda Pharmaceutical Co. and Protagonist Therapeutics. Analysts cited by Reuters said Takeda has suggested Mimrylo could generate $1 billion to $2 billion in peak sales in polycythemia vera.

Broader pipeline

Silence is also developing zerlasiran for people at elevated cardiovascular risk because of high levels of lipoprotein(a), a blood protein linked to heart disease. The company’s earlier-stage programs target high cholesterol, obesity and immune-related diseases.

The deal is Merck’s latest move to expand its healthcare portfolio. It follows the company’s $3.9 billion acquisition of SpringWorks Therapeutics in 2025 and its pending $11.3 billion takeover of life-sciences tools maker Bio-Techne.

Deal terms

Silence’s board unanimously approved the transaction, as did Merck’s relevant corporate bodies. Shareholders holding about 14% of Silence’s voting power have agreed to support the deal.

The acquisition is expected to close in the first quarter of 2027, subject to approval by Silence shareholders, sanction by the High Court of Justice of England and Wales and customary regulatory approvals. It will be carried out through a scheme of arrangement under Part 26 of the U.K. Companies Act 2006.

Silence shares, listed on Nasdaq under the ticker SLN, more than doubled in morning trading after the announcement.