MSD, a large pharmaceutical company, has agreed to buy Cidara Therapeutics for $9.2 billion. This deal will add a new type of long-lasting drug technology to MSD’s lineup. MSD will pay $221.50 per share in cash to acquire Cidara, a US biotech company that has developed a platform of drug-Fc conjugates (DFCs). This technology allows Cidara to create molecules that last longer in the body and do not need the immune system to work, unlike traditional vaccines. Cidara’s main product, CD388, is designed to prevent influenza A and B. It is a small molecule linked to a part of a human antibody. In an interview last October, Cidara’s CEO Jeff Stein said they improved the drug’s properties so it can be given once per flu season. CD388 is currently being tested in a Phase III study in adults and adolescents who are at higher risk of complications from the flu. It showed success in an earlier Phase IIb study, which helped it gain special status from the US Food and Drug Administration (FDA). MSD’s president Dr. Dean Li said this acquisition complements their respiratory portfolio and pipeline. For MSD, buying Cidara and CD388 could be a strong growth opportunity in the infectious disease sector. The US government has also seen the promise of Cidara’s technology, awarding the biotech a $339 million funding award to support domestic manufacturing of CD388. The long-lasting nature of CD388 has several advantages over vaccines in fighting seasonal viruses like the flu. Stein added that CD388’s manufacturing process won’t need to change yearly, making it more feasible to stockpile. For MSD, this acquisition is another billion-dollar deal in 2025, following the acquisition of Verona Pharmaceuticals for $10 billion in July. MSD is looking to strengthen its pipeline as the patent for its blockbuster cancer drug Keytruda is nearing its end. Analysts are uncertain about the market chances of a new version of Keytruda. Reacting to the Cidara acquisition, Citi analysts said in a research note that while the deal makes strategic sense, the flu vaccine landscape may be challenging due to regulatory uncertainty.