Merck KGaA announced an agreement to acquire Silence Therapeutics in an all-cash transaction valued at approximately $1.3 billion in equity value and $1.1 billion in enterprise value.
The $20-per-ADS offer represents a 130% premium to Silence's October 16 closing price. The acquisition includes divesiran, an investigational siRNA therapy targeting TMPRSS6 for polycythemia vera, alongside a broader RNA-interference platform and pipeline.
Silence's Phase II SANRECO trial reported clinical response in 88% of divesiran-treated patients versus 19% receiving placebo, with Phase III initiation anticipated in the first half of 2027. Completion of the acquisition is expected in Q1 2027, subject to shareholder, court, and regulatory approvals. Silence Therapeutics
Primary sources: Silence acquisition announcement, October 19 · SANRECO Phase II results
Why it matters strategically
The acquisition brings a new competitive dimension to the polycythemia vera market.
On August 28, the FDA approved Mimrylo, developed by Protagonist Therapeutics and commercialized by Takeda Pharmaceutical.
Rusfertide directly mimics hepcidin, whereas divesiran inhibits TMPRSS6 expression to increase endogenous hepcidin production.
Both approaches influence iron availability and erythrocyte production, but their pharmacological mechanisms and dosing schedules differ.
The commercial distinction may become particularly important.
Rusfertide is administered weekly.
Divesiran's Phase II program evaluated administration every six or twelve weeks.
However, dosing convenience alone does not establish clinical superiority.
The Phase II SANRECO results cannot be directly compared with Phase III VERIFY response rates because the studies used different populations, assessment periods, and endpoint definitions.
That distinction must be preserved in any BBIU assessment.
Critical evidence discrepancy
There is an additional issue worth investigating.
Silence's October 19 acquisition announcement states that no approved therapies specifically target red blood cells and hematocrit.
Yet Takeda's August 28 announcement explicitly confirms FDA approval of Mimrylo for erythrocytosis in adults with PV.
The wording in Silence's announcement therefore appears outdated or insufficiently qualified. This matters because the commercial valuation of divesiran must reflect an existing approved competitor, not an uncontested future market.
