Merck KGaA agreed to acquire Silence Therapeutics for $1.3 billion in an all-cash transaction, adding a late-stage rare blood-cancer siRNA program to its pipeline. The purchase brings Divesiran, an RNAi candidate targeting TMPRSS6 in polycythemia vera to raise hepcidin and limit iron availability for red blood cell production. Merck said the deal strengthens its capabilities in targeted specialty and rare diseases, with closing expected in the first quarter of 2027. Silence and Merck will remain independent until the transaction completes, but the asset adds a mechanism of action distinct from standard PV approaches like phlebotomy and cytoreductive therapy. Strategically, the acquisition signals continued demand for clinically focused RNAi platforms in hematology and a push to add assets that can differentiate against chronic, high-burden care pathways.