Merck KGaA to Buy Silence Therapeutics (SLN) for $20 a Share: Why the Stock More Than Doubled

Silence Therapeutics shares more than doubled on Monday, October 19, 2026, after Merck KGaA of Darmstadt, Germany agreed to buy the company for $20.00 in cash per American depositary share (ADS), an equity value of about $1.3 billion. The ADSs traded at $19.57, up 125.52% from Friday's close of $8.68. The buyer is the German group Merck KGaA, which is a separate company from the US drugmaker Merck & Co.

The offer is 130% above the Friday close and 82% above the 30-day volume-weighted average price of $10.99. Including Silence's cash, the enterprise value is about $1.1 billion. Merck KGaA said it will pay with new debt.

Merck pays more than August's investors paid

Two months ago Silence sold $175 million of new ADSs at $13.50 each, the day after it reported positive Phase 2 results for its lead drug. By Friday the ADSs had fallen to $8.68, about 36% below that offering price, and we found no company announcement that explains the slide. Merck's $20.00 is 48% above what the August buyers paid.

The gap between the $1.3 billion equity value and the $1.1 billion enterprise value implies about $200 million of net cash, most of it from that August sale. Silence held $72.1 million at the end of June, before the offering.

What Merck KGaA is buying

The deal centers on divesiran, a small interfering RNA (siRNA) drug that silences TMPRSS6, a gene involved in controlling iron levels. Silence is developing it for polycythemia vera, a rare blood cancer in which patients make too many red blood cells and often need blood drawn to keep their levels down. In the Phase 2 SANRECO trial, reported on August 10, 2026, 88% of patients on divesiran responded, against 19% on placebo. The drug has Fast Track and Orphan Drug status from the FDA, and Silence planned to start a Phase 3 trial in the first half of 2027.

Merck KGaA described the purchase as part of its push into targeted specialty and rare diseases. It is the group's second rare-disease deal in about 15 months: it completed the purchase of SpringWorks Therapeutics on July 1, 2025, paying $47 a share, about $3.9 billion in equity value.

Why the ADSs trade just below $20

At $19.57 the ADSs sit 2.2% below the offer price. That gap is what a holder collects if the deal closes as planned in early 2027, and its size reflects the months until closing and the chance that a vote or a regulator blocks the deal. Holders of about 14% of the voting power have already agreed to support the deal, and both boards backed it unanimously.

Silence's other main drug, zerlasiran, which lowers lipoprotein(a), was not named in Merck KGaA's announcement. Silence had said it would start a Phase 3 trial of zerlasiran only once it found a partner.