Germany’s Merck KGaA has agreed to acquire British biotechnology company Silence Therapeutics for approximately $1.3 billion in cash, accelerating its expansion into specialized medicines and emerging genetic technologies as pharmaceutical companies seek new sources of growth.
Under the agreement announced Monday, Merck will pay $20 for each American depositary share of Silence Therapeutics, representing a 130% premium to the company’s previous closing price, according to Reuters. Shares of the Nasdaq-listed biotechnology company more than doubled in U.S. trading following the announcement.
The acquisition gives Merck access to Silence’s portfolio of experimental treatments based on small interfering RNA, or siRNA, a technology designed to prevent the production of proteins associated with disease. The approach allows drug developers to target biological processes that can be difficult to address with conventional medicines.
The transaction also strengthens Merck’s position in rare diseases, an increasingly important area of pharmaceutical investment as drugmakers pursue treatments for smaller patient populations with significant unmet medical needs.
Experimental Blood Cancer Treatment Drives Deal
A central component of the acquisition is divesiran, Silence Therapeutics’ experimental treatment for polycythemia vera, a rare form of blood cancer characterized by excessive red blood cell production.
Patients with the disease frequently undergo therapeutic blood removal procedures to reduce elevated red blood cell levels and limit complications.
Divesiran is expected to advance into Phase 3 clinical testing after encouraging results from an earlier study. According to Reuters, Silence reported in August that the treatment reduced patients’ reliance on blood-removal procedures while helping control measures associated with excessive blood thickness.
If approved, divesiran could enter a competitive market that includes Mimrylo, a treatment developed by Takeda Pharmaceutical and Protagonist Therapeutics.
Reuters cited William Blair analyst Myles Minter as suggesting the acquisition price could be attractive given the potential commercial opportunity in polycythemia vera and the additional value of Silence’s broader drug-development platform. Takeda has indicated potential peak sales of $1 billion to $2 billion for Mimrylo, according to the report.
Beyond divesiran, Silence is developing zerlasiran, an investigational therapy targeting elevated lipoprotein(a), a cardiovascular risk factor. Its research portfolio also includes early-stage programs addressing cholesterol disorders, obesity and immune-related conditions.
Merck Accelerates Acquisition Strategy
The Silence transaction marks another significant investment by the Darmstadt-based pharmaceutical and life-sciences group as it reshapes its business through acquisitions.
Merck purchased U.S. biotechnology company SpringWorks Therapeutics for approximately $3.9 billion in 2025, expanding its presence in specialized cancer and rare-disease treatments.
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The company has also announced an approximately $11.3 billion acquisition of Bio-Techne, a U.S. supplier of life-sciences research technologies, which remains pending.
Together, the transactions highlight Merck’s strategy of acquiring established scientific platforms and promising clinical assets rather than relying exclusively on internally developed medicines.
The Silence acquisition adds a different technological capability to that strategy.
Unlike traditional drugs that often act on proteins after they have been produced, siRNA therapies interfere with the genetic messages involved in protein production. The technology could potentially support treatments across several therapeutic areas, although individual candidates must still demonstrate safety and effectiveness in clinical trials.
For Merck, ownership of Silence’s proprietary platform could provide opportunities beyond the company’s most advanced experimental medicines.
Regulatory Approval and Competition Remain Key Factors
Despite the potential benefits, Merck will inherit the clinical and commercial uncertainties associated with Silence’s development pipeline.
Divesiran has not yet completed late-stage testing, and its future market position will depend on clinical outcomes, regulatory decisions and competition from other treatments.
The purchase also comes as pharmaceutical companies increasingly compete for biotechnology assets with promising clinical results and specialized research capabilities.
Merck’s willingness to pay more than twice Silence’s previous market valuation reflects the strategic importance it places on the company’s technology and development programs.
The companies expect to complete the acquisition during the first quarter of 2027 through a court-supervised arrangement under UK law, subject to required approvals and customary closing conditions.
If completed, the transaction would give Merck a broader portfolio of experimental RNA-based medicines and another potential route into the market for rare-disease treatments.
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