Merck to Acquire Silence Therapeutics
Merck has entered into a definitive agreement to acquire biotech company Silence Therapeutics, focused on siRNA-therapies in areas of high unmet need.
The purchase price represents an enterprise value of $1.1 billion and an equity value of approximately $1.3 billion. Silence Therapeutics, headquartered in London, UK, employs approximately 80 people and operates from locations in the UK, the US and Germany.
“The planned acquisition of Silence Therapeutics will strengthen our capabilities to serve patients with targeted specialty and rare diseases,” said Kai Beckmann, Chairman of the Executive Board and Group CEO of Merck. “Following the acquisition of SpringWorks Therapeutics last year, we continue to transform our pipeline toward areas of high specialization and unmet medical need, with an ongoing commitment to external innovation. The proposed transaction follows Merck’s strategic priority to address attractive end markets also through M&A, creating value over the mid- to long-term.”
The transaction, once completed, will add Divesiran ─ a potentially best-in-class, phase 3-ready siRNA investigational therapy in development for phlebotomy-dependent polycythemia vera (PV) ─ to Merck’s pipeline. Divesiran is dosed subcutaneously once every 3 months.
PV is a chronic myeloproliferative neoplasm ─ a type of rare blood cancer ─ characterized by the excessive production of red blood cells, which 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, Divesiran aims to limit iron availability for red blood cell production, helping to control hematocrit levels and potentially reducing the need for frequent therapeutic phlebotomies.
Divesiran met its primary endpoint in the Phase 2 SANRECO study with an 88% responder rate versus 19% for placebo (p<0.0001) and reduced mean phlebotomies to 0.2 per patient versus 2.1 on placebo over weeks 0–36 (p<0.0001), irrespective of background cytoreductive therapy. Divesiran was observed to be well-tolerated and no new safety findings were observed in the trial. Injection site reactions were infrequent and self-limiting. There were two cases of Grade 1 anemia which were assessed as related to treatment by an investigator.
“The planned acquisition of Silence Therapeutics marks a significant step forward in our strategy to become a Global Specialty Innovator in Healthcare,” said Danny Bar-Zohar, member of the Executive Board and CEO Healthcare at Merck. “Silence Therapeutics’ primary siRNA pipeline asset, Divesiran, is supported by promising Phase 2 efficacy data, a potentially best-in-class, once-every-three-month dosing schedule, and a safety profile that appears manageable, with the added advantage of targeting a well-defined, homogeneous patient population. The planned acquisition also provides an entry point into hematology through a biologically validated mechanism of action. With this transaction, we are advancing our efforts to build a differentiated, sustainable pipeline as we bring more medicines to more patients, faster.”
Merck, a leading science and technology company headquartered in Darmstadt, Germany, operates across life science, healthcare and electronics. In 2025, Merck generated sales of €21.1 billion.
