The $20-per-share acquisition represents a 130% premium as Merck expands its rare disease pipeline and strengthens its position in RNA-based medicines.
German pharmaceutical and technology company Merck KGaA has agreed to acquire Silence Therapeutics (NASDAQ: SLN) in an approximately $1.3 billion all-cash transaction, highlighting growing interest in gene-silencing therapies and rare disease treatments. The deal, announced Monday, October 19, offers Silence shareholders $20 per American Depositary Share (ADS), representing a substantial 130% premium to the company’s closing price of $8.68 on Friday.
The acquisition values Silence Therapeutics at approximately $1.3 billion in equity and $1.1 billion in enterprise value. The purchase price also represents an 82% premium to the company’s 30-day volume-weighted average share price, underscoring the strategic value Merck places on its emerging drug pipeline.
At the center of the transaction is divesiran, an experimental RNA-based treatment targeting polycythemia vera, a rare form of blood cancer characterized by the excessive production of red blood cells. The condition can increase the risk of blood clots, strokes, and other serious cardiovascular complications, often requiring patients to undergo regular blood removal procedures to control their red blood cell levels.
Divesiran uses small interfering RNA (siRNA) technology to selectively silence a gene involved in regulating iron metabolism. By limiting iron availability for red blood cell production, the therapy aims to reduce the need for frequent blood removal treatments while improving disease management.
Recent Phase 2 clinical trial results have strengthened the drug’s potential. In the SANRECO study, divesiran achieved an 88% response rate compared with 19% for patients receiving placebo. Patients receiving the experimental therapy also required significantly fewer blood removal procedures, providing encouraging evidence ahead of planned Phase 3 development.
One potential advantage of divesiran is its dosing schedule. The treatment is designed to be administered through an injection once every three months, potentially offering patients a more convenient alternative to therapies requiring more frequent administration.
For Merck, the acquisition represents another step in its strategy to expand into specialized treatments addressing significant unmet medical needs. The company previously acquired SpringWorks Therapeutics in 2025, strengthening its presence in rare diseases and oncology. Adding Silence Therapeutics provides access to a promising late-stage drug candidate and a broader platform for developing RNA-based medicines.
The transaction also highlights the growing importance of gene-silencing technology within the biotechnology industry. Unlike traditional medicines that target proteins after they are produced, siRNA therapies work by reducing the production of specific disease-related proteins, potentially offering more targeted treatment approaches.
For biotechnology investors, the 130% acquisition premium demonstrates how promising clinical data can significantly increase the strategic value of smaller drug developers. Large pharmaceutical companies continue seeking innovative assets to replenish their pipelines, diversify revenue streams, and establish positions in emerging treatment categories.
However, divesiran remains investigational and must successfully complete additional clinical testing before potentially receiving regulatory approval. Its commercial prospects will depend on demonstrating sustained effectiveness, safety, and competitive advantages over existing treatments.
The transaction has received unanimous approval from Silence Therapeutics’ board and is expected to close during the first quarter of 2027, subject to shareholder, regulatory, and court approvals.
The acquisition reinforces a broader trend in biotechnology: pharmaceutical companies are increasingly willing to pay substantial premiums for innovative therapies supported by promising clinical results. As RNA-based medicine continues advancing, smaller biotechnology companies developing differentiated treatments could attract further acquisition interest from larger industry players.
