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# Sanofi Petitions FDA to Add Study Failure in Fluad Labeling
- URL: https://www.fdaweb.com/sanofi-petitions-fda-to-add-study-failure-in-fluad-labeling/
- Published: 2022-03-04T12:00:00.000Z
- Updated: 2026-09-14T17:35:17.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5151295

Sanofi has petitioned FDA requesting that it mandate a labeling change to Seqirus’ influenza vaccine products Fluad and Fluad Quadrivalent to reflect that a confirmatory study failed to verify clinical benefit. The request is presumably intended to give Sanofi a competitive edge for its Fluzone Quadrivalent influenza vaccine.

Sanofi’s [petition](https://downloads.regulations.gov/FDA-2022-P-0270-0001/attachment%5F1.pdf?ref=fdaweb.com) urges FDA to require Seqirus to amend the labeling for both products, which were approved under the accelerated approval pathway, so that they “contain a description of the limitations of existing evidence, including a description of results from an absolute efficacy confirmatory study that failed to meet its primary efficacy endpoints.”

The confirmatory study’s primary efficacy endpoint, according to the petition, was to demonstrate absolute vaccine efficacy of Fluad Quadrivalent versus a non-influenza comparator when administered as a single dose to prevent first influenza occurrence. “Ultimately, the absolute vaccine efficacy was estimated to be 19.80%,” Sanofi argues, “which did not meet the pre-specified criterion of lower limit greater than or equal to 40%.” Sanofi notes that Seqirus explained this failure to meet its primary endpoint by stating that most influenza cases were caused by A/H3N2 strains and were antigenically unmatched to the vaccine strain.