Merck KGaA, Darmstadt, Germany, has entered into a definitive agreement to acquire Silence Therapeutics plc in an all-cash transaction valued at approximately $1.3 billion. The proposed acquisition will add Divesiran, an investigational small interfering RNA (siRNA) therapy being developed for phlebotomy-dependent polycythemia vera (PV), to Merck’s healthcare pipeline. The treatment is considered ready for Phase 3 development.
Divesiran Targets Polycythemia Vera
PV is a chronic myeloproliferative neoplasm and a type of rare blood cancer characterized by excessive red blood cell production. The condition can be associated with a higher rate of death from cardiovascular and thrombotic events.
Divesiran is designed to selectively silence TMPRSS6, a gene involved in regulating hepcidin, the body’s key regulator of iron metabolism. By increasing hepcidin levels, the treatment aims to restrict the iron available for red blood cell production. This could help control hematocrit levels and potentially reduce the need for frequent therapeutic phlebotomies.
The investigational therapy is administered through a subcutaneous injection once every three months.
Phase 2 Study Results
Divesiran met the primary endpoint in the Phase 2 SANRECO study, achieving an 88% responder rate compared with 19% for placebo. The difference was statistically significant, with a p-value below 0.0001.
The study also recorded a mean of 0.2 phlebotomies per patient in the Divesiran group, compared with 2.1 in the placebo group over weeks zero to 36. This difference was also statistically significant. The results were observed irrespective of whether participants were receiving background cytoreductive therapy.
According to the supplied study information, Divesiran was well tolerated, and no new safety findings were observed. Injection-site reactions were infrequent and self-limiting. Two cases of Grade 1 anemia were assessed by an investigator as related to treatment.
Danny Bar-Zohar, a member of Merck’s Executive Board and CEO Healthcare, said the planned acquisition would support the company’s strategy of becoming a Global Specialty Innovator in Healthcare. He described Divesiran as having “a potentially best-in-class, once-every-three-month dosing schedule” and noted that the transaction would provide Merck with an entry point into hematology through a biologically validated mechanism.
Acquisition Terms and Approval Process
Under the agreement, Merck will pay $20 in cash for each American Depositary Share (ADS) of Silence Therapeutics. Each ADS represents three ordinary shares, equivalent to approximately $6.67 per ordinary share. The transaction carries an estimated equity value of $1.3 billion and an enterprise value of $1.1 billion.
The offer represents an 82% premium to Silence Therapeutics’ 30-day volume-weighted average share price of $10.99 as of October 16, 2026, the last trading day before the announcement.
The transaction has been unanimously approved by Silence Therapeutics’ board and Merck’s relevant corporate bodies. Completion is expected in the first quarter of 2027, subject to customary closing conditions, including required regulatory approvals and approval by Silence Therapeutics shareholders.
Securityholders representing approximately 14% of Silence Therapeutics’ voting power have entered into an agreement to support the transaction. The acquisition will be carried out through a UK scheme of arrangement and financed using proceeds from new debt.
Silence Therapeutics’ Research Pipeline
Silence Therapeutics is headquartered in London and employs approximately 80 people across the UK, the US and Germany. The company focuses on designing and developing siRNA therapies for areas of high unmet medical need.
Merck said the acquisition follows its purchase of SpringWorks Therapeutics in 2025 and reflects its strategy of expanding its pipeline through external innovation and acquisitions.
Iain Ross, interim principal executive officer and chairman of Silence Therapeutics’ board, said the agreement followed a competitive sale process and would place the company’s programs within Merck. He also said the transaction would provide a setting for advancing Divesiran’s Phase 3 development.
Merck Expands Its Rare Disease Portfolio With a Major Acquisition
Merck KGaA, the Germany-based science and technology company, announced on October 19, 2026, that it had entered into a definitive agreement to acquire UK-based Silence Therapeutics in an all-cash transaction valued at approximately $1.3 billion in equity value. The acquisition is intended to strengthen Merck’s specialty medicine portfolio and expand its capabilities in RNA-based therapies for rare diseases.
The agreement gives Merck access to Silence Therapeutics’ proprietary small interfering RNA (siRNA) technology and its leading experimental drug candidate, divesiran, which is being developed for polycythemia vera, a rare blood cancer.
