Moderna's RSV shot nabs FDA breakthrough tag, boosting position in race with Pfizer, GSK

Moderna’s respiratory syncytial virus (RSV) vaccine for older adults has scored breakthrough designation from the FDA as the three-way race with Pfizer and GSK nears the finish. 

The Cambridge, Massachusetts-based company’s announcement Monday comes two weeks after it posted competitive phase 3 data of the vaccine, mRNA-1345. The shot was found to be 83.7% effective against RSV-associated lower respiratory tract disease defined by two or more symptoms, with the majority of side effects rated as mild or moderate. Moderna says the phase 3 data was used to gain U.S. regulators’ breakthrough nod. 

The designation for Moderna has practical application to expedite the FDA’s review of the company’s vaccine, but it’s also symbolic, showing that the drugmaker is hot on the heels of Pfizer and GSK. The latter two pharmas have received priority review status and Moderna planning to use a priority review voucher—in all cases trimming the FDA review period by four months. 

“With this designation, we look forward to productive conversations with the FDA in the hopes of bringing our RSV vaccine candidate for older adults to the market safely and quickly,” said Moderna CEO Stéphane Bancel in a release. 

Moderna is a few months behind GSK and Pfizer in the RSV regulatory sprint, however, and plans to apply for approval in the first half of 2023. GSK had its application accepted by the FDA in early November 2022 with Pfizer’s accepted a month later. Sanofi is taking a different approach, developing nirsevimab as a protective antibody for infants; the FDA accepted Sanofi’s approval application earlier this month. 

The windfall of potential RSV preventatives marks a watershed moment in the fight against the virus, after years of failure have culminated in four encouraging candidates. Depending on when Moderna submits its application, all four could reach the market before the year ends.

Editor's note: This story was updated to clarify the designations granted to GSK's RSV vaccine.