Merck KGaA Acquires Silence Therapeutics for $1.3B to Advance Blood Cancer Drug

Key points

• Merck KGaA is acquiring Silence Therapeutics for $1.3 billion in an all-cash transaction, paying $20 per ADS.
• The primary asset is divesiran, an siRNA drug for polycythemia vera that silences the TMPRSS6 protein in liver cells to reduce red blood cell production.
• Phase 2 data showed an 88% response rate for divesiran between weeks 18 and 36, with 93.8% efficacy in the six-week dosing cohort and 81.3% in the 12-week cohort.
• Silence plans to use a 12-week dosing regimen for divesiran in phase 3 trials, contrasting with Takeda’s Mimrylo, which requires weekly injections.
• Silence’s pipeline also includes zerlasiran for atherosclerotic cardiovascular disease and SLN312 for dyslipidemia, both of which lost previous partners (Hansoh Pharma and AstraZeneca, respectively) in 2025 and 2026.
• Merck CEO Kai Beckmann stated the acquisition aligns with his strategy to broaden M&A scope and address rare diseases, following a $11 billion deal for Bio-Techne in June 2026.

Background

This acquisition fits into Merck KGaA’s recent aggressive expansion strategy under CEO Kai Beckmann, who took over in May 2026. The company previously acquired Bio-Techne for over $11 billion in June and SpringWorks Therapeutics in 2025. Meanwhile, the broader pharmaceutical landscape has seen significant M&A activity, including Merck & Co.’s $2.13 billion deal for a KRAS inhibitor from SciBrunch in September 2026 and AstraZeneca’s $2 billion investment in Summit Therapeutics in October 2026. These moves reflect a trend among major pharma companies to secure specialized therapies and rare disease treatments through external innovation rather than solely relying on internal R&D.

Why it matters

The acquisition validates the commercial potential of siRNA therapies for rare blood cancers and provides Merck with a differentiated competitor to Takeda’s Mimrylo. By securing a 12-week dosing regimen, Silence’s divesiran could offer a significant convenience advantage over weekly injections, potentially influencing market share in the polycythemia vera segment. For Merck, the deal diversifies its pipeline beyond oncology into rare diseases and cardiovascular conditions, aligning with its strategic pivot toward high-specialization areas. The transaction also highlights the value of mid-stage clinical success in biotech acquisitions, as Silence’s strong phase 2 data attracted a premium despite the loss of previous partnerships for its other pipeline assets.

What to watch

Merck will likely initiate phase 3 trials for divesiran to confirm its efficacy and dosing advantages over Mimrylo. The company may also evaluate the future development of Silence’s other assets, zerlasiran and SLN312, which lack current partners. Investors will watch how Merck integrates Silence’s siRNA platform into its broader R&D strategy and whether the acquisition impacts Merck’s valuation and market position in the rare disease sector.