Merck KGaA, Darmstadt, Germany, has entered a definitive agreement to acquire Silence Therapeutics, a London-based, clinical-stage biotechnology company focused on short interfering RNA (siRNA) therapies for areas of high unmet need.

The all-cash transaction values Silence Therapeutics at an enterprise value of $1.1 billion and an equity value of approximately $1.3 billion, with shareholders set to receive $20 per American depositary share, or $6.6667 per ordinary share, representing an 82% premium to the company’s 30-day volume-weighted average price as of October 16, 2026, the last trading day before the announcement.¹

Back in 2017, Pharmaceutical Executive spoke with then CEO of Merck KGaA, Darmstadt, Germany’s healthcare business, Belén Garijo, who touched on the company’s product pipeline. “Our healthcare business is less dependent on Germany and Europe while the product portfolio has broadened beyond our traditional MS franchise to include products in the most promising therapeutic segments, including next generation immuno-oncologic drugs and combinations and in immunology,” said Garijo.

What does the deal include?

The acquisition grants Merck KGaA, Darmstadt, Germany, access to Silence’s divesiran, a potentially best-in-class, phase III-ready siRNA investigational therapy in development for phlebotomy-dependent polycythemia vera.^1,2 

The transaction was unanimously approved by both companies’ boards and is expected to close in the first quarter of 2027, subject to regulatory approvals and a vote by Silence Therapeutics shareholders under a U.K. scheme of arrangement.¹ Securityholders representing roughly 14% of Silence Therapeutics’ voting power have already agreed to vote in favor.¹ Merck KGaA, Darmstadt, Germany, plans to fund the acquisition through proceeds from new debt.

How does divesiran work?

Divesiran is designed to selectively silence TMPRSS6, a gene that regulates hepcidin, the body’s primary iron-metabolism hormone.² By raising hepcidin levels, the therapy aims to limit iron available for red blood cell production, helping control hematocrit levels and potentially reducing patients’ need for frequent therapeutic phlebotomies.²

In the phase II sanreco study, divesiran met its primary endpoint with an 88% responder rate versus 19% for placebo (p<0.0001), and cut mean phlebotomies to 0.2 per patient versus 2.1 on placebo over weeks zero through 36 (p<0.0001), regardless of background cytoreductive therapy.¹ The company reports that the therapy is well tolerated, with infrequent, self-limiting injection-site reactions and two cases of grade 1 anemia assessed by an investigator as treatment-related; no new safety findings emerged.¹

Merck KGaA, Darmstadt, Germany, frames the acquisition as an extension of its specialty-pipeline strategy. “The planned acquisition of Silence Therapeutics will strengthen our capabilities to serve patients with targeted specialty and rare diseases,” says Kai Beckmann, chairman of the Executive Board and group CEO of Merck KGaA, Darmstadt, Germany. “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.”

Danny Bar-Zohar, member of the Executive Board and CEO Healthcare at Merck KGaA, Darmstadt, Germany, points to the clinical and commercial profile behind the deal. “Silence Therapeutics’ primary siRNA pipeline asset, divesiran, is supported by promising phase II 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,” he says. “The planned acquisition also provides an entry point into hematology through a biologically validated mechanism of action.”

What’s next?

Assuming the deal closes as expected in early 2027, Merck KGaA, Darmstadt, Germany, intends to advance divesiran into phase III development, betting that its scale and commercial infrastructure can accelerate the program toward patients faster than Silence Therapeutics could alone.¹

Sources

1. Merck KGaA, Darmstadt, Germany to Acquire Silence Therapeutics, Strengthening Rare Disease Pipeline with Innovative siRNA Asset Merck KGaA, Darmstadt, Germany, October 19, 2026, https://www.businesswire.com/news/home/20261019777870/en/Merck-KGaA-Darmstadt-Germany-to-Acquire-Silence-Therapeutics-Strengthening-Rare-Disease-Pipeline-with-Innovative-siRNA-Asset
2. Silence Therapeutics Our Pipeline/ Divesiran Silence Therapeutics Date Accessed October 19, 2026, https://silence-therapeutics.com/our-pipeline/sln124/default.aspx