BREAKING: Merck & Co. has officially announced its acquisition of Cidara Therapeutics for approximately $9.2 billion, a strategic move aimed at significantly enhancing its antiviral pipeline. This deal, confirmed today, focuses on Cidara’s lead candidate, CD388, which is currently in Phase III trials aimed at preventing influenza in high-risk individuals.
The acquisition is particularly urgent as CD388 is designed to provide broad protection against both seasonal and pandemic influenza strains. The drug utilizes a unique long-acting formulation that combines a neuraminidase inhibitor with a proprietary human antibody fragment. As part of the Phase III ANCHOR trial (NCT07159763), CD388 is being tested among adults and adolescents identified as vulnerable to severe influenza complications.
Robert M. Davis, Merck’s chairman and CEO, stated, “We intend to build on the Cidara team’s remarkable progress and are confident that CD388 has the potential to be another important driver of growth through the next decade, creating real value for shareholders.”
This acquisition follows Cidara’s recent success in its Phase IIb NAVIGATE trial, which reported a significant prevention efficacy (PE) of up to 76.1% for high-dose participants against symptomatic laboratory-confirmed influenza, demonstrating the drug’s potential as a vital option alongside existing vaccines and antivirals.
The ANCHOR trial, initiated in September 2023, targets an enrollment of 6,000 participants across 150 sites in the United States and the United Kingdom. The study is expected to conduct an interim analysis in Q1 2026, assessing the efficacy and safety of CD388 in preventing influenza.
Cidara has also garnered significant support from the Biomedical Advanced Research and Development Authority (BARDA), receiving a contract worth up to $339.2 million to aid in the manufacturing of CD388. This funding underscores the urgency of addressing unmet needs in influenza prevention.
Merck’s acquisition of Cidara is a critical step in its strategy to counteract the impending revenue losses from patent expirations on several blockbuster drugs, including Keytruda®, which generated over $23 billion in revenue in the first three quarters of 2023.
The deal, which involves Merck purchasing all outstanding shares of Cidara for $221.50 per share—an impressive 109% premium over Cidara’s closing price—has received approval from both companies’ boards and is expected to finalize in the first quarter of 2026.
As investors react positively, Cidara’s shares surged over 105% today, closing at $217.71 on NASDAQ. Merck’s shares remained stable at $92.93 on the New York Stock Exchange.
Jeffrey Stein, Cidara’s president and CEO, remarked on the transformative nature of the acquisition: “This milestone represents a transformational moment for Cidara and for our mission to redefine influenza prevention.”
As this story develops, experts and stakeholders in the pharmaceutical industry will be closely monitoring the implications of this acquisition on both companies and the broader landscape of antiviral treatments. The urgency of enhancing influenza prevention measures has never been more critical, especially as the flu season approaches.
Stay tuned for further updates on this significant development in antiviral therapeutics.
