SAN DIEGO – Merck & Co Inc (NYSE: MRK), known as MSD outside the U.S. and Canada, said on Saturday it will acquire Cidara Therapeutics Inc (Nasdaq: CDTX) in a $9.2 billion all-cash deal, bolstering its respiratory pipeline with a late-stage antiviral candidate aimed at preventing influenza.
Under the terms of the agreement, Merck will pay $221.50 per share for Cidara, a premium that reflects the strategic value of its lead asset, CD388. The drug-Fc conjugate (DFC) therapeutic is currently in Phase 3 trials and has received Breakthrough Therapy and Fast Track designations from the U.S. Food and Drug Administration.
“We continue to execute our science-led business development strategy,” said Merck CEO Robert M. Davis. “CD388 has the potential to be another important driver of growth through the next decade.”
CD388 is designed to prevent influenza A and B in high-risk populations, including older adults and immunocompromised individuals. The candidate met all endpoints in the Phase 2b NAVIGATE study and is now being evaluated in the ANCHOR Phase 3 trial.
Cidara CEO Jeffrey Stein called the deal “transformational,” citing Merck’s global scale and regulatory expertise as key to advancing CD388 to market.
The acquisition, approved by both companies’ boards, is expected to close in Q1 2026 pending regulatory clearance and shareholder approval. Merck said the transaction will be accounted for as an asset acquisition.