Merck KGaA buys Silence in $1.3B deal after siRNA drug's phase 2 blood cancer win

Biotech Merck KGaA buys Silence in $1.3B deal after siRNA drug's phase 2 blood cancer win By James Waldron Oct 19, 2026 8:57am Merck KGaA Silence Therapeutics Licensing deals siRNA Germany’s Merck KGaA has picked up Silence Therapeutics to the tune of $1.3 billion in the wake of the British biotech’s mid-stage success for its challenger to Takeda’s Mimrylo. The all-cash deal will see Darmstadt-based Merck pay $20 per share of Silence—an 130% increase on the biotech’s Friday closing price of $8.68. The biggest prize for Merck is divesiran, a short interfering RNA (siRNA) drug candidate designed to treat a rare blood cancer called polycythemia vera (PV).

The cancer is characterized by the excessive production of red blood cells and the idea is that divesiran silences the production of a protein, TMPRSS6, found in liver cells, in order to redirect iron delivery away from bone marrow and slow production of red blood cells. This theory appeared to pan out in August, when Silence revealed that 88% of patients on divesiran in a phase 2 study had met the response criteria between Weeks 18 and 36. The response rate was 93.8% in people who received divesiran every six weeks and 81.3% in the 12-week dose cohort.

The data, which Silence is using as a springboard into phase 3, puts the biotech as a strong follower to Takeda and Protagonist’s Mimrylo, which was approved by the FDA in PV in August. Related Silence brings the noise to Takeda with phase 2 blood cancer win Silence’s hopes for overcoming Mimrylo’s head start hinge on its dosing regimen. Mimrylo, which mimics a hormone that regulates iron homeostasis, was given as a weekly, self-administered injection in phase 3, while Silence plans to administer divesiran every 12 weeks in its own phase 3 trial.

Silence’s pipeline also includes zerlasiran, a siRNA therapy designed to treat atherosclerotic cardiovascular disease by silencing the LPA gene. Future development plans for the drug were in limbo last year after China’s Hansoh Pharma pulled out of an mRNAi-focused collaboration with Silence. The only other asset from Silence to make it into the clinic is SLN312, a siRNA therapy designed to silence ANGPTL3 as a way to treat dyslipidemia.

AstraZeneca handed back its rights to partner on the drug earlier this year. Iain Ross, interim principal executive officer and chairman of Silence’s board, said the deal with Merck was “the result of a competitive sale process and delivers significant, immediate and certain value to our shareholders.” “This transaction follows potentially best-in-class phase 2 polycythemia vera data for divesiran and reflects the important progress we have made advancing our differentiated siRNA pipeline,” Ross added. “It also provides a new home for our innovative programs within Merck KGaA ...

placing divesiran with a company that has the scale, resources and commercial capabilities to accelerate its phase 3 development and bring this potentially best-in-class siRNA therapy to patients in need.” The Silence acquisition validates the commitment of Merck’s new CEO Kai Beckmann to “broaden our M&A scope.” Beckmann took over in May after Belén Garijo moved to Sanofi, and the following month saw the German pharma front over $11 billion to buy Bio-Techne. Beckmann put today’s deal in the context of Merck’s “strategic priority to address attractive end markets through M&A, creating value over the mid- to long-term.” “The planned acquisition of Silence Therapeutics will strengthen our capabilities to serve patients with targeted specialty and rare diseases,” the CEO added in the release. “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.” Where Big Pharma is placing its bets is one of the hot topics being discussed at Fierce Biotech's high-impact event in London next month.

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