Merck & Co. has announced a definitive agreement to acquire UK-based Verona Pharma for approximately $10 billion, a strategic move aimed at bolstering its respiratory treatment offerings. The acquisition, expected to close in the fourth quarter of 2025 pending regulatory and shareholder approvals, underscores Merck’s commitment to expanding its presence in the cardio-pulmonary therapeutic area.
Central to the acquisition is Verona Pharma’s flagship product, Ohtuvayre (ensifentrine), a novel inhaled therapy approved by the U.S. Food and Drug Administration (FDA) in June 2024 for the maintenance treatment of chronic obstructive pulmonary disease (COPD) in adults. Ohtuvayre combines bronchodilator and non-steroidal anti-inflammatory effects, representing the first new inhaled mechanism for COPD treatment in over two decades .
Since its U.S. launch in August 2024, Ohtuvayre has demonstrated rapid market uptake, with Verona reporting $71.3 million in net sales during the first quarter of 2025, nearly doubling its total sales for 2024 . The drug is also undergoing clinical trials for the treatment of non-cystic fibrosis bronchiectasis, a chronic lung condition characterized by airway damage.
The acquisition aligns with Merck’s strategic objective to diversify its revenue streams in anticipation of the 2028 patent expiration of its blockbuster cancer drug, Keytruda. In 2024, Keytruda generated $29.5 billion in revenue, accounting for a significant portion of Merck’s income . By integrating Ohtuvayre into its portfolio, Merck aims to mitigate potential revenue declines and reinforce its position in the respiratory treatment market.
Merck Chairman and CEO Robert M. Davis stated, “Ohtuvayre complements and expands our pipeline and portfolio of treatments for cardio-pulmonary diseases while delivering near- and long-term growth as well as value for shareholders” .
Under the terms of the agreement, Merck will acquire Verona Pharma at $107 per American Depository Share (ADS), representing a 23% premium over Verona’s closing price prior to the announcement. The transaction will be financed through a combination of cash, commercial paper, and new debt .
Following the announcement, Verona Pharma’s U.S.-listed shares surged 21% to $104.92, reaching an all-time high. Merck’s shares experienced a modest increase of 2%, although they remain down 16% year-to-date .
COPD is a progressive lung disease affecting over 14 million adults in the United States and is a leading cause of morbidity and mortality. The disease imposes an estimated $50 billion annual economic burden on the U.S. healthcare system . The introduction of Ohtuvayre offers a new therapeutic option for patients and may capture a significant share of the growing COPD market, which is projected to expand from $17 billion in 2025 to $27 billion by 2032 .
The acquisition of Verona Pharma represents Merck’s largest deal since its $10.8 billion purchase of Prometheus Biosciences in 2023 and reflects the company’s ongoing strategy to invest in innovative therapies that address unmet medical needs. The integration of Ohtuvayre into Merck’s portfolio is expected to enhance the company’s long-term growth prospects and solidify its position in the respiratory treatment landscape.
