Efforts to innovate within the combat in opposition to influenza embody a number of failed common flu vaccines. Merck is aiming for universality with a drug, not a vaccine, through the $9.2 billion acquisition of Cidara Therapeutics, a biotechnology firm whose lead program brings properties of each small molecule and biologic therapies to supply long-acting safety in opposition to viral pathogens.
The deal introduced Friday comes as San Diego-based Cidara continues Part 3 testing of its influenza drug candidate, CD388. For Merck, the deal diversifies its pipeline by including a late-stage asset with blockbuster potential together with a platform know-how that would help the pharmaceutical big’s drug R&D work in infectious illness and past.
Cidara’s medicine have two primary elements, every with a unique mechanism of motion. The primary half is a small molecule designed to bind to a goal on the floor of the pathogen to inhibit viral proliferation. The small molecule is conjugated to the second part, the Fc area of the human antibody IgG1. This protein fragment extends a Cidara drug’s half-life and engages the immune system to offer a further response. Cidara calls this new kind of remedy a drug-Fc conjugate, or DFC.
CD388 incorporates a number of copies of small molecule inhibitors of neuraminidase, an enzyme discovered on the floor of flu viruses. Neuraminidase inhibitors are already broadly obtainable in flu antiviral merchandise corresponding to Tamiflu from Roche and Relenza from GSK. In Cidara’s drug, the neuraminidase inhibitors are conjugated to an Fc fragment. Cidara is growing this DFC for the prevention of influenza an infection in these at greater threat of flu issues. The corporate has mentioned that as a result of CD388 shouldn’t be a vaccine, it doesn’t depend on an immune response and is predicted to work in these with weaker immune programs. Additionally, its long-acting impact presents the potential for cover throughout your complete flu season.
This previous June, Cidara reported preliminary information from a placebo-controlled Part 2b research that enrolled about 5,000 unvaccinated adults. Outcomes confirmed the subcutaneously injected drug met the research’s primary purpose, demonstrating statistically vital prevention efficacy for every of the three doses examined. The research drug was protected and properly tolerated.
In September, Cidara started a Part 3 research whose begin was accelerated by six months with the intention to overlap with the 2025 flu season within the Northern Hemisphere. This system will proceed into the spring of subsequent yr to enroll contributors within the Southern Hemisphere. Merck mentioned an interim evaluation is deliberate for the primary quarter of 2026 to evaluate trial measurement and powering assumptions, and likewise to find out whether or not to extend enrollment past the 6,000 contributors deliberate for the research.
With the Cidara acquisition, Merck is getting an asset that Johnson & Johnson deserted. In 2021, Cidara entered a partnership with J&J subsidiary Janssen Prescribed drugs, which secured world rights to CD388 and took over Part 2 improvement. However in 2023, Janssen stopped work on a lot of its infectious illness pipeline, together with the Cidara antiviral. Final yr, Cidara reacquired rights to CD3888 and raised funding to proceed mid-stage medical improvement of this system.
Merck can even get Cloudbreak, the proprietary Cidara platform know-how that yielded CD388. Cloudbreak has extra purposes in oncology and it has produced DFCs for targets in strong tumors, the place the biotech mentioned such a remedy might have benefits over antibody drug conjugates. Cidara has been exploring enterprise alternatives for these preclinical packages, however Merck would possibly select to maintain them for its personal most cancers pipeline.
Merck’s portfolio is headlined by the most cancers immunotherapy Keytruda, which accounted for $29.4 billion in income in 2024 and is at the moment the corporate’s top-selling product. However Keytruda faces patent expiration in 2028, so Merck has been placing enterprise offers for late-stage medicine with the potential to exchange Keytruda’s income. Earlier this yr, Merck paid $10 billion to purchase Verona Pharma, whose blockbuster prospect Ohtuvayre is authorized for treating persistent obstructive pulmonary illness and has potential purposes in different respiratory problems. Merck’s enterprise improvement efforts in 2024 included offers that introduced blockbuster prospects for most cancers and eye illnesses.
The $9.2 billion acquisition worth for Cidara breaks right down to $221.50 in money per share. That’s greater than double the inventory’s Thursday closing worth. When Cidara went public in 2015, the then preclinical biotech priced its shares at $16 apiece. Cidara’s inventory worth has been climbing steadily because the June report of Part 2 information for CD388.
“This acquisition expands and enhances our respiratory portfolio and pipeline,” Dean Li, president of Merck Analysis Laboratories, mentioned in a ready assertion. “Influenza continues to pose a big world well being risk, inflicting widespread sickness, morbidity and loss of life annually particularly in older adults and immunocompromised people, corresponding to these with most cancers and persistent illnesses.”
The Merck and Cidara boards of administrators have authorized the transaction, which is predicted to shut within the first quarter of 2026. Merck has scheduled a Monday 8 a.m. investor name to debate the deal.
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