First Biologic for Pediatric CSU Approved: Here's What It Means for Your Patients

If you've cared for a child with chronic spontaneous urticaria (CSU), you know the clinical reality: The hives are unpredictable, the itch is relentless, and conventional options often fall short.¹ The FDA's recent approval of dupilumab (Dupixent; Regeneron/Sanofi) for children aged 2 to 11 years with antihistamine-refractory CSU changes that picture in a meaningful way.²

"The only thing more frustrating than failing to pinpoint a specific cause of hives in your [patients with] chronic urticaria is failing to provide them with complete symptomatic relief," said Andrew Krakowski, MD, a double board-certified pediatric dermatologist at St Luke’s University Health Network and dermatologist with more than 20 years of experience. "I'm talking about knocking out the itch, knocking out the urticaria they experience in their skin."

That frustration is well founded. In CSU, a cause often can't be identified—and by definition, the hives have been present for at least 6 weeks. The condition can occur alongside angioedema, a swelling of the deeper tissues that can become life-threatening in certain clinical situations.³ And even on first-line H1 antihistamines—cetirizine (Zyrtec; Kenvue), fexofenadine (Allegra; Sanofi), loratadine (Claritin; Bayer)—up to half of patients don't achieve complete symptomatic relief.

"We know that in up to 50% of patients on conventional first-line treatment…up to half of those patients fail to obtain complete symptomatic relief," Krakowski said. "And what are they left with?"

Until recently, the answer for pediatric patients was: not much.

A Mechanism That Addresses the Disease, Not Just the Symptoms

Dupilumab works by blocking IL-4 and IL-13 signaling, 2 cytokines that drive the type 2 inflammation underlying CSU. That's a fundamentally different approach from antihistamines, which target downstream symptom control at the H1 receptor without addressing the inflammatory cascade driving the disease.⁴

For dermatology clinicians, that mechanistic distinction matters practically. This isn't another step-up antihistamine strategy; it's a new rung on the treatment ladder entirely.

"I'm excited to finally have a second rung on my treatment ladder for managing CSU," Krakowski said.

What the Data Show

The FDA's decision is grounded in the LIBERTY-CUPID phase 3 program. In studies A and C—replicate, double-blind, placebo-controlled trials in antihistamine-refractory patients aged 6 years and older—dupilumab significantly reduced itch severity and urticaria activity at week 24. Patients on dupilumab were also more likely to achieve well-controlled disease (Urticaria Activity Score [UAS7] ≤ 6) or complete response (UAS7 = 0) compared with placebo.

For patients aged 2 to 11 years specifically, the single-arm CUPIDKids (NCT05526521) trial established pharmacokinetics and safety, with efficacy extrapolated from adult and adolescent data. Dosing in this age group is weight- and age-based. No new safety signals were identified, and the overall safety profile was consistent with dupilumab's established record across its other approved indications.

Speed of Response: A Practical Advantage

For patients and families who have been managing unpredictable flares for months or years, the timeline of response is clinically relevant, and Krakowski sees it as one of the approval's more compelling practical features.

"I also like that this appears to be a relatively fast-acting medicine," he said. "People aren't waiting years to get their CSU under control; they're seeing relief in weeks."

The speed of onset matters for quality of life, particularly in young children, for whom uncontrolled hives and itch can disrupt sleep, school, and daily routines during critical developmental years.

The Broader Significance for Pediatric Derm

More than 14,000 US children aged 2 to 11 years are estimated to have antihistamine-refractory CSU. For this population, dupilumab is now the first biologic option ever approved in the US.² Krakowski emphasized that the age-range extension reflects not only a regulatory milestone but also a growing body of pediatric safety data accumulated across dupilumab's multiple indications—including atopic dermatitis, asthma, and bullous pemphigoid.

"It speaks to the overall amount of patient safety data we now have, not just for dupilumab in the setting of [CSU], but in aggregate for its use in other medical conditions," he said. "I'm very happy to be both a champion and an advocate for my young patients who can now celebrate that this medicine has been approved down to 2 years of age."

For advanced practice providers who are often the first point of contact for families cycling through antihistamines without relief, this approval provides a concrete option to offer patients—a targeted therapy with a well-characterized safety profile and a mechanism designed to treat the disease at its source.

References

1. Chin ML. It comes and goes: pediatric chronic spontaneous urticaria. Cureus. 2023;15(6):e40006. doi:10.7759/cureus.40006
2. Sanofi and Regeneron’s Dupixent approved in the US as the first biologic medicine for young children with uncontrolled chronic spontaneous urticaria. News release. Sanofi. April 22, 2026. Accessed April 29, 2026. https://www.news.sanofi.us/2026-04-22-Sanofi-and-Regenerons-Dupixent-approved-in-the-US-as-the-first-biologic-medicine-for-young-children-with-uncontrolled-chronic-spontaneous-urticaria
3. Tbakhi B, Ware K, Park HS, Bernstein JS, Bernstein JA. An overview of chronic spontaneous urticaria: diagnosis, management, and treatment. Allergy Asthma Immunol Res. 2025;17(5):531-546. doi:10.4168/aair.2025.17.5.531
4. Licari A, Manti S, Leonardi S, et al. Biologic drugs in chronic spontaneous urticaria. Acta Biomed. 2021;92(S7):e2021527. doi:10.23750/abm.v92iS7.12415