A study with three years of follow-up shows that the drug stays effective and safe for most, although 16% stopped getting treated with Dupixent, mainly because it was ineffective or caused side effects.
The FDA approved Dupixent (dupilumab) as a treatment for moderate to severe atopic dermatitis for adolescents in 2019, then for children ages 6 to 11 a year later, and, two years later, for very young children, ages 6 months to 5 years. And that is to say nothing of a slew of approvals for other conditions.
By patient population, 2017–2022
Expanded to youngest patients (ages 6 months–5 years)
Expanded to children (ages 6–11 years)
Expanded to adolescents (ages 12–17 years)
Initial approval (adults)
Source: FDA approval announcements, Regeneron & Sanofi, 2017–2022
But those approvals were based on relatively short and small studies that aren’t designed to address questions about longer-term efficacy and safety.
Dupixent wasn’t, however, a successful treatment for all the children in this study. The findings show that 50, or approximately 16%, of the children and adolescents discontinued taking Dupixent, 19 of whom did so because it was ineffective and 15 because of side effects.
Still, the researchers’ conclusion said the results show that Dupixent “provided long-term clinical effectiveness across all pediatric age groups with AD [atopic dermatitis] for up to 3 years of follow-up in a clinical setting.”
Corresponding author Marlies de Graaf, M.D., Ph.D., head of the National Expertise Center of Atopic Dermatitis in Children, in the Department of Dermatology and Allergology at the University Medical Center of Utrecht, in the Netherlands, conducted the study by tapping into a patient registry that included four academic and three nonacademic hospitals in the Netherlands. They looked at patients 16 years and younger who started treatment with Dupixent between November 2019 and October 2025. Dupixent’s approval dates in the Netherlands are slightly different than those in the U.S., but the sequence is the same: It was approved for adolescents, children and, finally, very young children. De Graaf and her colleagues grouped the young patients in their study into three age groups: 138 were in the 12 to 16 age group, 120 in the 6 to 11 group, and 51 in the 6 months to 5 years group. The average age was 10.2 years.
The efficacy outcomes they looked at are commonly used in dermatology studies: the Eczema Area and Severity Index (EASI) and the average Numeric Rating Scale (NRS) for pruritus, and some scales that measure quality of life. Safety, including side effects, was assessed using the data collected at each patient visit.
The EASI and other efficacy results showed roughly the same pattern: substantial improvement during the first 4 to 16 weeks of treatment, and then a plateau or more gradual improvement through the three years of follow-up. For example, the average EASI score for the entire cohort improved to 4.6 after 16 weeks, dropped to 4.1 at 1.5 years, and dipped to 3.4 after three years of treatment. The NRS for pruritus improved to 3.5 at 16 weeks and stayed at approximately that level through three years.
At 1.5 years, 76 patients achieved a composite score of an EASI of 7 or less and an NRS score for pruritus of 4 or less.
De Graaf and her colleagues noted that the pruritus and quality of life gains were smaller among the youngest children even though EASI scores were the same. They suggested that the pruritus and quality scores may be because parents and other caregivers report those outcomes, which may not fully capture what the young patient is experiencing.
Side effects were common. The findings reported by de Graaf and her colleagues show that more than half (195 of the 309 patients, or 63%) experienced a side effect. But only 15 patients (4.9%) discontinued treatment because of the side effects compared with 19 who did so because Dupixent was ineffective. The most common side effect was dupilumab-associated ocular surface disease (DAOSD), a range of eye-related issues that typically occur within four months of starting Dupixent. DAOSD includes nonspecific symptoms and well-charactered conditions, such as
