Merck KGaA agreed to buy UK-based Silence Therapeutics for $1.3 billion to gain control of its siRNA program for rare disease. The deal targets divesiran, which delivered positive Phase 2 results in polycythemia vera, and is positioned as a specialized, genetic-medicine platform expansion for Merck KGaA. Under the terms reported, Merck KGaA will pay $20 in cash per Silence share, representing a 130% premium, with plans to close in the first quarter of 2027. Silence’s investors representing a minority block (14% of voting power) already agreed to the transaction, according to the deal terms. Analysts cited in the report said the Phase 2 efficacy profile could raise competitive expectations in polycythemia vera, where current standards include Jakafi and Takeda’s Mimrylo in development. Merck KGaA will need to advance divesiran through Phase 3 as it looks to differentiate in a crowded rare-hematology landscape. The transaction underscores how large pharma is continuing to build capabilities in RNA medicine, using acquisition to accelerate pipeline access rather than relying solely on internal discovery timelines.