Merck & Co. to Acquire Verona Pharma for $10 Billion, Boosting Respiratory Portfolio

Merck & Co., Inc. has announced a definitive agreement to acquire UK-based Verona Pharma for approximately $10 billion, aiming to enhance its respiratory treatment portfolio. The acquisition includes Ohtuvayre (ensifentrine), a first-in-class maintenance therapy for chronic obstructive pulmonary disease (COPD) in adults.

Under the terms of the agreement, Merck will pay $107 per American Depositary Share (ADS) of Verona Pharma, each representing eight ordinary shares. This offer reflects a 23% premium over Verona's closing price on July 8, 2025. The transaction is expected to close in the fourth quarter of 2025, pending shareholder and regulatory approvals.

Ohtuvayre, approved by the U.S. Food and Drug Administration (FDA) in June 2024, is a dual inhibitor of phosphodiesterase 3 and 4 (PDE3 and PDE4), combining bronchodilator and non-steroidal anti-inflammatory effects. It represents the first novel inhaled mechanism for COPD treatment in over two decades. Since its launch, Ohtuvayre has shown strong market performance, with net product sales of $36.6 million in the fourth quarter of 2024 and $42.3 million for the full year. By February 2025, more prescriptions had been filled than in the entire fourth quarter of 2024, with over 4,600 unique healthcare professionals prescribing the medication.

Merck's acquisition of Verona Pharma aligns with its strategy to diversify its portfolio beyond its flagship cancer drug, Keytruda, which generated nearly $30 billion in revenue in 2024 and faces patent expiration in 2028. Analysts project that Ohtuvayre could generate annual sales exceeding $3 billion by the mid-2030s.

Following the announcement, Verona Pharma's stock surged 20% in pre-market trading, while Merck's shares experienced a slight increase. This acquisition is Merck's largest since its $10.8 billion purchase of Prometheus Biosciences in 2023, reflecting the company's commitment to expanding its pipeline in anticipation of upcoming patent expirations.

COPD affects over 14 million adults in the United States, representing a significant public health challenge. The introduction of Ohtuvayre offers a new treatment option for patients, potentially improving quality of life and reducing healthcare costs associated with COPD management.

The pharmaceutical industry has seen a trend of significant mergers and acquisitions aimed at diversifying portfolios and mitigating revenue losses from patent expirations. In 2025 alone, global pharmaceutical and biotech M&A deals have totaled $105.3 billion, marking a 7% increase from the previous year and the highest year-to-date total since 2023.

Merck's acquisition of Verona Pharma underscores the company's strategic focus on expanding its respiratory treatment portfolio and addressing the needs of patients with chronic respiratory conditions.