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Sanofi announces positive Phase 1/2 study interim results for its first mRNA-based vaccine candidate

PARIS – September 28, 2021 – Positive interim results from a Phase 1/2 study1 of Sanofi’s mRNA-based COVID-19 vaccine candidate confirm the potential of recently-acquired Translate Bio’s messenger RNA (mRNA) and lipid nanoparticle (LNP) platform and support Sanofi’s mRNA strategy.

The initial data from Phase 1/2 showed neutralizing antibody seroconversion (defined as 4-fold increase vs baseline) in 91% to 100% of study participants, two weeks after a second injection, across all 3 dosages tested. No safety concern has been observed and the tolerability profile is comparable to that of other unmodified mRNA COVID-19 vaccines. Further data from this first study of Sanofi’s mRNA platform will be presented at a later date.

“We are happy to see those positive initial results. We have made an impressive move just 9 months after the worldwide proof of concept of mRNA vaccines and only 17 since we started this first mRNA vaccine project”, says Jean-Francois Toussaint, Global Head of Research and Development, Sanofi Pasteur. “These results will clearly help inform the path forward for our mRNA development programs. Today, we have a promising mRNA platform, which we’re taking to the next level in development, including moving to modified mRNA, and against other diseases, including flu.”

Targeting 2022 initiation of its clinical studies for an influenza vaccine with modified mRNA, Sanofi launched a Phase 1 clinical trial in June 2021 evaluating an mRNA-based investigational vaccine against seasonal influenza. The trial will evaluate the safety and immunogenicity of a monovalent flu vaccine candidate coding for the hemagglutinin protein of the A/H3N2 strain of the influenza virus across two formulations (MRT5400 and MRT5401) with different lipid nanoparticles.

At the same time, Sanofi continues its efforts in the fight against the COVID-19 pandemic with its adjuvanted recombinant protein candidate vaccine, developed in partnership with GSK. In parallel to its ongoing Phase 32 efficacy and safety study, Sanofi has expanded its development program to include a study of the vaccine as a potentially broadly protective booster to address evolving public health needs. Recently published preclinical data3 indicated the candidate has the potential to strongly boost immune responses following primary vaccination across multiple vaccine technology platforms and against a broad spectrum of variants of concern. The booster studies4 began this summer in the U.S., Australia, France, and the UK. First results are expected by the end of Q4 2021.

Sanofi also keeps its commitment to making a strong contribution to current global public health priorities, with the supply of half a billion doses of authorized vaccines. Sanofi is the only company leveraging its worldwide manufacturing capacity and expertise for the supply of three different authorized COVID-19 vaccines from BioNTech / Pfizer, Moderna, and Johnson & Johnson. Manufacturing teams on three industrial sites of the company in France, Germany and the U.S. are mobilized, with 30 million doses released so far.

About the Sanofi and GSK partnership
In the partnership between the two Companies, Sanofi provides its recombinant antigen and GSK contributes its pandemic adjuvant, both established vaccine platforms that have proven successful against influenza. The recombinant technology combined with GSK’s adjuvant is designed to offer the advantages of stability at temperatures used for routine vaccines, making it easily implementable and easier to distribute at a global scale through existing infrastructures where vaccines are stored at normal refrigerator temperature. It is also designed to offer the potential to generate high and sustained immune responses, and the potential to prevent virus transmission.

This effort is supported by federal funds from the Biomedical Advanced Research and Development Authority, part of the office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services in collaboration with the U.S. Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense under Contract # W15QKN-16-9-1002.

About Sanofi
Sanofi is dedicated to supporting people through their health challenges. We are a global biopharmaceutical company focused on human health. We prevent illness with vaccines, provide innovative treatments to fight pain and ease suffering. We stand by the few who suffer from rare diseases and the millions with long-term chronic conditions. With more than 100,000 people in 100 countries, Sanofi is transforming scientific innovation into healthcare solutions around the globe.

Posted: September 2021

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