On April 18, 2025, Sanofi officially inaugurated its latest research and development (R&D) unit dedicated to vaccines in Marcy-l'Etoile, located in the Rhne-Alpes region of France. This state-of-the-art facility will serve as a hub for biotechnology research, equipped with a comprehensive arsenal of technological platforms aimed at expediting the development of new vaccines, particularly those based on messenger RNA (mRNA).

As a pioneer in mRNA technology within France, Sanofi has made a substantial investment of 120 million in the construction of this new R&D unit, which has received co-funding from both the European Union and the Auvergne-Rhne-Alpes region. This significant investment reinforces Sanofi's crucial role in the innovation and deployment of mRNA technologies. Since 2022, the company has invested a staggering total of 935 million to establish a unique and autonomous value chain for mRNA within the country, making it the sole entity in France with comprehensive control over this cutting-edge technology.

The new XL building is specifically designed to consolidate all activities related to the pharmaceutical development of vaccines into a single space. This strategic colocation of various teams responsible for different technologies will enhance synergies and foster collaboration among experts, thereby optimizing the entire vaccine development cycle. Notably, the facility allows for the execution of critical stages in the development of mRNA-based vaccines right in France, from the internalized production of plasmidswhich serve as templates for mRNA strandsto their encapsulation in lipid nanoparticles and the final distribution of the product into vials.

Jean-Franois Toussaint, the Global Head of Vaccine Research and Development at Sanofi, emphasized the significance of this XL unit, stating, "Our XL unit is a major asset in accelerating the development of innovative vaccines for millions of patients worldwide. Its versatility, combined with the expertise of our scientific teams now gathered in one location, will reinforce our excellence in research and development."

Charles Wolf, the General Director of Sanofi France, echoed this sentiment by highlighting the company's strong commitment over the past five years to actively contribute to France's health sovereignty. He remarked, "This new excellence unit, fully dedicated to accelerating our vaccine R&D, aligns perfectly with our innovation strategy, in which France already plays a significant role."

Fully operational since April 2025, this XL facility supports Sanofi's entire portfolio of new vaccines while also targeting innovative future vaccine candidates, such as therapeutic vaccines for chlamydia and acne. Spanning an impressive 14,000 square meters, the unit directly employs nearly 300 scientists within the Marcy-l'Etoile site, which already hosts around 3,200 employees.

In addition to the new facility, the sites of Vitry-sur-Seinededicated to monoclonal antibodiesand Neuville-sur-Sane, home to the worlds first modular vaccine and biomedicine production plant inaugurated in September 2024, bolster Marcy-lEtoiles strategic role in promoting excellence in immunology.

During the construction of this XL building, Sanofi collaborated with a unique network of nearly ten engineering firms and French subcontractors based in the Auvergne-Rhne-Alpes region. As the largest employer in the area with nearly 5,000 employees across its various sites, Sanofi plays a vital role in the economic vitality of the region and actively contributes to its reputation as a European hub in the fields of Science and Health.

With an annual investment exceeding 2.5 billion in R&D in France, Sanofi stands out as the leading private investor in this sector within the country. The company has placed innovation at the heart of its ambitions, aiming to become a global leader in immunology to serve millions of patients and populations worldwide, targeting diseases such as asthma, multiple sclerosis, type 1 diabetes, and chronic bronchitis.

About Sanofi
We are a global health company, driven by a mission: to continue the miracles of science to improve people's lives. Around the world, our teams strive to transform medical practice to make the impossible possible. We provide therapeutic solutions that can change patients' lives and vaccines that protect millions globally, guided by our commitment to sustainable development and social responsibility.

Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY.

Sanofi Contacts:
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Lo Le Bourhis | +33 6 75 06 43 81 | leo.lebourhis@sanofi.com
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Victor Rouault | +33 6 70 93 71 40 | victor.rouault@sanofi.com
La Ubaldi | +33 6 30 19 66 46 | lea.ubaldi@sanofi.com