Galderma Laboratories has landed a blow on Sanofi in its multi-case advertising row, driving the French drugmaker to change or drop certain claims about its blockbuster medicine Dupixent.
Last year, the BBB National Programs’ National Advertising Division (NAD) ruled against Galderma in two cases brought by Sanofi. In October, the NAD recommended that Galderma change or drop some claims about Nemluvio, an IL-31 drug that, like Dupixent, is used to treat prurigo nodularis (PN) and eczema. Two months later, the NAD recommended that Galderma change or drop other claims about Nemluvio.
Now, Galderma has struck back. Following a challenge by Galderma, the NAD recommended that Sanofi change or drop claims linking Dupixent to long-lasting clearer skin and fast itch relief. The U.S. advertising self-regulatory body also advised Sanofi to change or drop a prescriber-facing Day 2 itch relief claim.
The NAD found that Sanofi’s evidence supports claims that some adults achieved clearer skin lasting four months to one year and that some experienced itch relief two weeks after the first dose. However, the advertising body recommended that Sanofi revise its TV claims to “clearly and conspicuously” disclose the response rate and that Dupixent was used in combination with topical corticosteroids.
An animated consumer-facing mechanism-of-action video likely conveyed the unsupported message that inhibition of IL-4 and IL-13 signaling alone is sufficient to address eczema, the NAD said. Dupixent targets IL-4 and IL-13.
Sanofi’s prescriber-facing claim that Dupixent reduced itch “starting as early as Day 2” was another cause of contention. The NAD found the post hoc analysis underpinning the claim failed to support Sanofi’s message that Dupixent demonstrated a meaningful treatment benefit beginning as early as Day 2. In its advertiser statement, Sanofi said that it “will comply with NAD’s recommendations.”
Galderma’s challenges to other Sanofi claims failed. The NAD found support for claims that Dupixent helps patients “stay ahead of eczema” and can “help heal your skin from within,” as well as for Sanofi’s statement that many adults saw 90% clearer skin. Sanofi can continue to make the 90% claim, although the NAD recommended against overstating the supporting evidence or obscuring the treatment context.
The NAD sided with Sanofi on the question of whether its ads conveyed the message that Dupixent is superior to all other FDA-approved eczema treatments. Galderma also failed to persuade the NAD that the challenged ads implied Dupixent prevents eczema progression and blocks the most important source of inflammation.
Sanofi and Galderma are rowing over ads amid a fight for market share. Dupixent is a multi-indication commercial juggernaut, generating sales of 5.2 billion euros ($6 billion) for Sanofi in the second quarter. But the more recently launched Nemluvio is starting to carve out a place in two indications treated by Sanofi’s drug.
Sales of Nemluvio, which the FDA approved in 2024, grew (PDF) more than 100% to $433 million in the first half of 2026. The U.S. accounted for most sales, and eczema was a bigger contributor than PN. In the U.S. from mid-June to early July, Nemluvio accounted for 42% of new patient starts in PN and 9% in eczema, Galderma said.