Covid-19: Sanofi stops development of its messenger RNA vaccine, but continues its most advanced project

The Sanofi laboratory will not develop phase 3 of the trials for its messenger RNA vaccine against Covid-19 – the last step before marketing, he announced Tuesday, September 28. “There is no public health need for another messenger RNA vaccine”, commented Thomas Triomphe, vice-president of the vaccines branch of the pharmaceutical group. Despite positive intermediate results for phase 1-2 of the trial of its messenger RNA vaccine, Sanofi believes that it would arrive too late on the market, while 12 billion doses of Covid vaccine will have been produced in the total by the end of the year.

Initial data from the messenger RNA technology trial shows seroconversion, that is, the production of antibodies, in 91% to 100% of participants two weeks after the second injection, states Sanofi. These positive results are verified for the three assays which were tested. In addition, no side effects were observed and the safety profile is comparable to that of other RNA Covid-19 vaccines, such as those developed by the German-American tandem Pfizer-BioNTech and by the American biotech Moderna. .

With this technology, the laboratory wanted to assess the ability to elicit an immune response. “But this one is strong”, commented Thomas Triomphe, vice-president of the vaccines branch of Sanofi. Sanofi had been working since March 2020 with Translate Bio on this vaccine, and even bought this American biotech at the beginning of August for some 2.7 billion euros.

“Equip France with an arsenal of messenger RNA vaccines”

Nevertheless, “The need is not to create new Covid-19 RNA vaccines, but to equip France and Europe with an arsenal of messenger RNA vaccines for a next pandemic, for new pathologies”, adds Thomas Triomphe.

The vaccine specialist has beefed up his arsenal on this new technology. At the end of June, the pharmaceutical group announced the creation of a center of excellence dedicated to messenger RNA vaccines, located at its sites in Cambridge, Massachusetts, in the United States, and Marcy-l’Etoile. (Rhône), near Lyon. The stated objective of this center: to integrate internally “ all the necessary capacities for development and production Of these new generation serums.

Sanofi says it wants to develop vaccines with this technology against other viruses, without side effects and with fewer constraints in terms of storage temperature. The group has already launched initial trials for a monovalent vaccine – with a single strain of virus – against seasonal influenza. He announced on Tuesday that he wanted to launch clinical trials against influenza next year, this time with a quadrivalent vaccine.

Sanofi is continuing the development of its other vaccine against Covid-19. The results of phase 3 on this other vaccine, based on a recombinant protein and developed with the British GSK, are still expected before the end of the year.