Merck KGaA Pays a 130% Premium for the Second Mover in Polycythemia Vera

Merck KGaA, Darmstadt, Germany is buying Silence Therapeutics for about $1.3 billion in equity value, a 130% premium for a Phase 2 siRNA that has not started Phase 3, weeks after Takeda opened the polycythemia vera market with a weekly hepcidin mimetic.

Merck KGaA, Darmstadt, Germany agreed on October 19, 2026 to acquire Silence Therapeutics in an all-cash deal valued at approximately $1.3 billion in equity and $1.1 billion in enterprise value. Holders of Silence American depositary shares will receive $20.00 in cash per ADS, or $6.6667 per ordinary share. That price is a 130% premium to the ADS close on Friday, October 16, 2026, and an 82% premium to the 30-day volume-weighted average of $10.99.

Silence's board approved the transaction unanimously. Securityholders with about 14% of voting power signed voting and support agreements. Iain Ross, Silence's interim principal executive officer and chairman, described the outcome as the result of a competitive sale process. Closing is expected in the first quarter of 2027 through a UK scheme of arrangement under Part 26 of the Companies Act 2006, subject to shareholder approval and High Court sanction.

The check is large for a company that, as of June 30, 2026, held $72.1 million in cash, spent $9.1 million on research and development in the second quarter, and posted a $12.3 million net loss. Merck KGaA is buying a dosing argument in a market that already has an approved drug.

Takeda got there first

On August 28, 2026, the FDA approved Mimrylo (rusfertide), Takeda's hepcidin mimetic, as the first drug of its kind for polycythemia vera. In the Phase 3 VERIFY trial, 293 adults were randomized 1:1 over 32 weeks to Mimrylo 19 mg subcutaneous once weekly, titrated, or placebo. Over that period, 76.9% of Mimrylo patients required no phlebotomies, versus 32.9% on placebo. The application received priority review.

Polycythemia vera is a rare myeloproliferative neoplasm, a type of blood cancer marked by excessive red blood cell production. Hematocrit above 45% is associated with a four-times higher rate of death from cardiovascular and thrombotic events, so treatment aims to keep hematocrit below that line. Standard of care has been repeated phlebotomies and cytoreductive agents. In its August Phase 2 materials, Silence said there are no approved therapies that specifically target red blood cells and hematocrit. Eighteen days later, Mimrylo arrived.

Phase 2 data, and a Phase 3 that has not started

Divesiran is a wholly owned siRNA from Silence's mRNAi GOLD platform. It silences TMPRSS6, a protein expressed almost exclusively in the liver and a negative regulator of hepcidin, the master controller of iron metabolism. Silencing TMPRSS6 is meant to raise hepcidin, restrict iron available to the bone marrow, and cut excessive red cell production.

In SANRECO, 48 phlebotomy-dependent patients entered a 36-week randomized, double-blind, placebo-controlled portion of divesiran 6 mg/kg subcutaneous every six weeks or every twelve weeks. The primary endpoint was met: 88% of divesiran patients versus 19% on placebo achieved a response, defined as no phlebotomy and hematocrit below 45% during weeks 18 to 36 (p<0.0001), a placebo-adjusted response rate of 69%. The every-six-weeks cohort responded at 93.8%. The every-twelve-weeks cohort responded at 81.3%. Mean phlebotomies per patient from weeks 0 to 36 were 0.2 on divesiran versus 2.1 on placebo (p<0.0001). The drug was well tolerated, with no new safety findings, two investigator-reported grade 1 anemia cases, and infrequent, self-limiting injection site reactions. Divesiran holds FDA Fast Track and Orphan Drug designations for polycythemia vera.

Those figures come from 48 patients, against placebo. Mimrylo already carries an approval on a 293-patient Phase 3. Silence anticipates a Phase 3 of divesiran every twelve weeks versus placebo in the first half of 2027. Merck KGaA is paying the premium before that trial has started, and the planned control arm is still placebo, not rusfertide.

The case for catching up is the calendar

The commercial logic rides on how often a patient has to inject. Mimrylo is a weekly shot. Divesiran's Phase 3 plan is every twelve weeks. If durable hematocrit control is what keeps patients off phlebotomy in practice, a quarterly schedule could still matter after a weekly incumbent is already on the market. That reading is an inference. SANRECO did not test divesiran against rusfertide, and the Phase 3 design Silence has described will not either.

The last unencumbered shot at the platform

The purchase also caps a thin stretch for Silence's siRNA franchise. Zerlasiran, a candidate that silences the LPA gene in atherosclerotic cardiovascular disease, saw future development plans left in limbo after China's Hansoh Pharma pulled out of an mRNAi-focused collaboration last year. Rights to SLN312, a siRNA against ANGPTL3 for dyslipidemia, were handed back by AstraZeneca earlier this year. Divesiran is the remaining clinical-stage asset carrying the platform.

For Merck KGaA, the deal fits a stated push into targeted specialty and rare diseases. Chief executive Kai Beckmann framed it that way, and it follows the SpringWorks Therapeutics acquisition last year. The company also agreed in June 2026 to buy Bio-Techne for $11 billion at $73 per share. Next to that check, $1.3 billion is a bolt-on. Next to Silence's cash, its stripped pipeline, and Takeda's August label, it is a follower price on a follower position.

Whether a quarterly TMPRSS6 silencer can outrun a weekly, already approved hepcidin mimetic is now Merck KGaA's problem. The trial that would have to show it has not begun.