Merck has initiated a tender offer to acquire Terns Pharmaceuticals for approximately $650 million, or $12.00 per share in cash, moving to secure a clinical-stage pipeline concentrated on metabolic dysfunction-associated steatohepatitis. The offer represents a 102% premium to Terns' $5.94 closing price on March 3, the last trading day before merger discussions became public. Terns shareholders have until April 22 to tender their shares.
Terns brings two Phase 2b candidates into Merck's metabolic portfolio. FXR agonist THR-β agonist combination THR-300 completed mid-stage trials in MASH patients in Q4 2024, while THR-149, a liver-targeted thyroid hormone receptor beta agonist, delivered biomarker reductions in a 142-patient trial that read out in September. Both assets avoid the GLP-1 mechanism that dominates current metabolic disease development, giving Merck orthogonal shots on goal in a liver disease market projected to exceed $35 billion by 2030. The acquisition fills a hepatology gap Merck hasn't addressed since discontinuing its own MASH candidate in 2019.
The timing reflects two realities. First, the MASH development landscape has consolidated sharply since Madrigal's resmetirom won FDA approval in March 2024, creating the category's first branded therapy and clarifying regulatory endpoints. Terns' dual-mechanism assets now carry de-risked clinical pathways, though neither has advanced beyond mid-stage. Second, Merck faces $18 billion in revenue exposure as Keytruda patents begin expiring in 2028, forcing aggressive pipeline expansion across oncology, vaccines, and now metabolic disease. The company allocated $1.3 billion to business development in 2024 and signaled continued appetite for bolt-on acquisitions in therapeutic areas adjacent to its immunology franchise.
The tender structure bypasses a traditional proxy vote, compressing the transaction timeline to approximately 45 days from launch. Merck secured commitments from Terns shareholders holding 23% of outstanding shares, providing a cushion above the 50% minimum tender condition. No financing contingency exists—Merck closed 2024 with $14.7 billion in cash and marketable securities. The deal includes a $26 million termination fee if Terns accepts a superior proposal, though the committed shareholder base and speed of execution make competing bids unlikely.
Allocators should track three developments. First, THR-300's Phase 3 design, expected by mid-2025, will clarify Merck's confidence in the FXR/THR-β combination and define the $400-600 million clinical spend required to reach approval. Second, watch for Merck's broader metabolic disease strategy—this acquisition suggests willingness to enter crowded categories through clinical-stage assets rather than early discovery. Third, monitor how Terns' Foster City site integrates into Merck's existing cardiometabolic research operations in Boston and whether the 47-person Terns team survives consolidation.
The transaction closes Merck's smallest acquisition since its $425 million Prometheus Biosciences royalty purchase in 2023, but the hepatology entry carries outsize strategic weight as oral MASH therapies begin reaching patients and diagnostic criteria standardize across geographies.