Merck KGaA, Darmstadt, Germany, expects the Silence Therapeutics acquisition to close in the first quarter of 2027. It will pay $20.00 in cash per American depositary share (ADS). That values Silence at about $1.3 billion. The companies announced the deal on 19 October 2026, after signing on 18 October. In return, Merck KGaA gets divesiran, an investigational siRNA for polycythaemia vera. Divesiran met its primary endpoint in a phase 2 trial in August. Its phase 3 trial has not started.
Silence Therapeutics acquisition timeline and approvals
Both companies give the first quarter of 2027 as the expected window. The transaction agreement also sets a long-stop date of 30 April 2027. That date extends by five business days in certain circumstances, according to the Form 8-K that Silence filed.
The deal runs through a UK scheme of arrangement under Part 26 of the Companies Act 2006. A scheme is a court-sanctioned route for buying a UK company. Once approved, it binds every shareholder.
The agreement sets a rough timetable. Silence must use reasonable best efforts to file a preliminary proxy statement within 25 business days of signing. Shareholder meetings must then follow within 45 days of the proxy materials being dispatched.
Three approvals stand between signing and completion:
- Scheme vote: a majority in number of holders voting, representing at least 75 per cent in value.
- Special resolution: at least 75 per cent of the voting rights of members present and voting.
- Court sanction: the High Court of Justice of England and Wales must sanction the scheme.
Other conditions include expiry of the US Hart-Scott-Rodino waiting period and approval under German antitrust law. The agreement has no financing condition. Merck KGaA says new debt will fund the purchase.
Holders of about 14 per cent of Silence’s voting power have agreed to vote in favour. Silence would owe Merck KGaA a $13 million termination fee in specified circumstances. These include a change of board recommendation or acceptance of a superior proposal.
A review of the filings on 19 October 2026 found no date for the shareholder meetings.
What is the price in the Silence Therapeutics acquisition?
Each ADS represents three ordinary shares, so $20.00 per ADS equals about $6.67 per share. Silence puts the equity value at about $1.3 billion and the enterprise value at $1.1 billion.
The price is a 130 per cent premium to the 16 October closing ADS price. It is 82 per cent above the 30-day volume-weighted average price of $10.99.
Iain Ross is chairman of the Silence board and interim principal executive officer. He called the deal “the result of a competitive sale process”. He said it delivers “significant, immediate and certain value to our shareholders”. Morgan Stanley and Centerview Partners advised Silence.
Merck KGaA framed the purchase as strengthening its rare disease pipeline. The release says it follows the acquisition of SpringWorks Therapeutics last year. Its June agreement to buy Bio-Techne was a different kind of deal. That $11.3 billion Bio-Techne acquisition centred on life science tools. The Silence Therapeutics acquisition also joins the 2026 run of billion-dollar takeovers. A review of every $1bn-plus biotech deal tracked that run through April.
What does Merck KGaA get with divesiran?
Divesiran is the core asset in the Silence Therapeutics acquisition. It is designed to silence TMPRSS6, a gene involved in regulating hepcidin, according to the Merck KGaA release. The release calls polycythaemia vera (PV) a chronic myeloproliferative neoplasm, a rare blood cancer. It describes divesiran as “a potentially best-in-class, phase 3-ready siRNA investigational therapy”.
Divesiran holds FDA Fast Track and Orphan Drug designations for PV. Neither designation guarantees approval.
What did the phase 2 SANRECO trial show?
Silence reported topline results on 10 August 2026. The press release gives the 48-patient figure. The Form 8-K for that announcement sets out the design. The 36-week portion was randomised, double-blind and placebo-controlled. The patients were phlebotomy-dependent. Divesiran was given by subcutaneous injection at 6 mg/kg, either every six weeks or every 12 weeks.
The primary endpoint was response. That meant no phlebotomy and haematocrit below 45 per cent during weeks 18 to 36. Response was 88 per cent with divesiran and 19 per cent with placebo (p<0.0001). By schedule, it was 93.8 per cent every six weeks and 81.3 per cent every 12 weeks.
The key secondary endpoint was phlebotomy rate. Mean phlebotomies per patient over weeks 0 to 36 were 0.2 with divesiran and 2.1 with placebo (p<0.0001).
Silence called the drug well tolerated, with no new safety findings. It reported two grade 1 anaemia events, both investigator-reported. It described injection-site reactions as infrequent and self-limiting.
The data have limits. The topline release gives no patient numbers per arm. Full results are expected at a future medical congress. A review on 19 October 2026 found no durability data beyond 36 weeks.
Silence plans a phase 3 trial of the every-12-week schedule against placebo in the first half of 2027. The Merck KGaA release does not give a phase 3 start date.
How does divesiran compare with Mimrylo?
The FDA approved Takeda’s Mimrylo (rusfertide) on 28 August 2026, according to the FDA novel approvals list. The indication is erythrocytosis in adults with PV. It is given by weekly subcutaneous injection, by the patient or a caregiver.
The Mimrylo label, revised in August 2026, describes the phase 3 VERIFY trial. It randomised 293 adults. The primary endpoint was no longer meeting phlebotomy eligibility between weeks 20 and 32. Response was 76.9 per cent with Mimrylo and 32.9 per cent with placebo.
The label also lists the unfavourable findings. Injection-site reactions occurred in 56 per cent of Mimrylo patients and 33 per cent on placebo. Anaemia occurred in 16 per cent versus 4.1 per cent. Thrombocytosis occurred in 8 per cent versus 0.7 per cent. Warnings cover thrombocytosis, injection-site reactions and embryo-fetal toxicity.
The two results cannot be compared directly. Divesiran’s data come from a phase 2 trial with 48 patients. Mimrylo’s come from a phase 3 trial with 293. The response definitions and measurement windows also differ. A review on 19 October 2026 found no head-to-head trial.
What does the Silence Therapeutics acquisition mean for UK readers?
Silence is headquartered in London, according to its filing. The scheme needs sanction from the High Court of Justice of England and Wales.
Divesiran is investigational, and its phase 3 trial is planned for 2027. Searches of the electronic medicines compendium on 19 October 2026 returned no result for rusfertide or Mimrylo.
What is still unknown?
Several points remain open:
- The shareholder meeting dates, which the scheme document should set.
- The phase 3 design and start date, which rest on Silence’s own statements.
- The full SANRECO dataset, including patient numbers per arm and durability.
- How Merck KGaA will handle Silence’s other programmes, which the deal documents do not describe.
The Silence Therapeutics acquisition still needs several steps before closing. The preliminary proxy filing is the next dated marker. The High Court sanction hearing follows the shareholder votes. A phase 3 start in 2027 would then begin to test the phase 2 result.
