Analysis
Merck KGaA, Darmstadt, Germany agreed to acquire Silence Therapeutics in an all-cash deal that values the London-based biotech's equity at approximately $1.3 billion, or $1.1 billion in enterprise value, the companies said Monday in a filing tied to Silence's SEC Form 8-K. Shareholders will receive $20.00 per American Depositary Share -- each representing three ordinary shares -- a 130% premium to Friday's closing ADS price and an 82% premium to the stock's 30-day volume-weighted average of $10.99.
What Merck KGaA is buying
Silence is a clinical-stage biotech built on its proprietary mRNAi GOLD siRNA platform, which silences disease-causing genes rather than targeting their protein products. Its lead candidate, Divesiran, silences TMPRSS6, a liver-specific gene, to raise hepcidin levels and starve excess red blood cell production in polycythemia vera, a rare blood cancer. Silence has reported what it calls potentially best-in-class Phase 2 PV data, and Divesiran holds FDA Fast Track and Orphan Drug designations. Merck KGaA says it intends to fund the drug's move into Phase 3 trials.
“Silence has reported what it calls potentially best-in-class Phase 2 PV data, and Divesiran holds FDA Fast Track and Orphan Drug designations.”
The deal, structured as a UK scheme of arrangement, has already won unanimous approval from Silence's board, and shareholders representing roughly 14% of voting power have signed support agreements. It still needs a majority shareholder vote, sanction from the High Court of Justice of England and Wales, and regulatory clearances, with the companies targeting a close in the first quarter of 2027. Silence intends to file a proxy statement with the SEC covering the vote, according to a related securities filing. Silence's financial advisers are Morgan Stanley and Centerview Partners; Merck KGaA's legal counsel is Cooley LLP.
A pattern in RNAi dealmaking
Silence's exit lands in a crowded siRNA field led by Alnylam Pharmaceuticals, which has built its business on partnerships and royalty-sharing deals with Novartis and Regeneron rather than being bought outright, alongside Arrowhead Pharmaceuticals and Ionis Pharmaceuticals, both of which have leaned on similar licensing structures. Merck KGaA's decision to acquire Silence wholesale, rather than license Divesiran, mirrors a broader pattern of pharma majors buying clinical-stage RNAi and gene-silencing biotechs outright once their lead asset clears Phase 2 -- a faster, costlier path to a single program than the multi-asset licensing deals that defined the RNAi sector's first decade.
What the headline misses: a 130% premium reflects what Merck KGaA is paying relative to where Silence traded before the deal was announced, not a guarantee the asset is worth that much. Divesiran is still a Phase 2 drug in a rare indication, and PV treatments carry real competitive risk from JAK inhibitors like Incyte's ruxolitinib, which already has an approved, reimbursed label. If Phase 3 data disappoints or regulators push back on the hepcidin mechanism, Merck KGaA will have paid a premium for an asset that never reaches commercial scale.
For biotech M&A watchers, the bigger signal is Merck KGaA's willingness to pay nearly double the undisturbed share price for a single rare-disease program -- a bet that Divesiran's addressable PV population, while small, carries enough pricing power to justify the premium once the limitations of existing treatments are factored in.
