Sanofi and Regeneron Withdraw Pediatric Dupilumab Growth Study: What Investors Should Know

Sanofi SA (SNY), Regeneron Pharmaceuticals (REGN) announced an update on their ongoing clinical study.

Sanofi and Regeneron recently updated a planned Phase 4 clinical study titled “An Open-Label, Single-Arm Study to Assess Growth and Bone Mineral Density in Children ≥6 to <12 Years of Age With Severe Atopic Dermatitis Treated With Dupilumab.” The goal was to understand how long-term treatment with dupilumab might affect height and bone strength in children with severe atopic dermatitis that is not controlled by standard skin creams. This work matters because dupilumab is already widely used, and clearer data on growth and bone health could shape long-term treatment decisions in pediatric patients.

The study focused on dupilumab, a biologic drug that targets specific immune signals involved in inflammation. It is already approved for moderate-to-severe atopic dermatitis in adults and children as young as six months. In this setting, the drug was intended to treat severe eczema symptoms while tracking whether children continue to grow normally and maintain healthy bone density over time.

The trial was designed as an interventional, single-arm, open-label study. All enrolled children would receive dupilumab, with no placebo or comparison group. Because it was open-label, both doctors and families would know the treatment being given. The primary purpose was treatment, with growth and bone health measured over the course of therapy to look for any meaningful patterns or safety signals.

The record indicates the study status is “withdrawn,” meaning it did not proceed as originally planned. The study was first submitted on September 15, 2025, and the most recent update to the listing was made on November 21, 2025. No primary completion date or overall completion date is listed, which aligns with the withdrawn status and suggests that no results are expected from this specific protocol.

For investors, the key takeaway is that this withdrawn pediatric study is unlikely to change the near-term outlook for Sanofi (SNY) or Regeneron (REGN). Dupilumab already has a strong commercial position in atopic dermatitis and other allergic diseases, and a single halted post-approval growth and bone study does not signal a known new safety problem on its own. However, the move can raise mild questions about strategy or feasibility around long-term pediatric safety work, especially as competitors in immunology and dermatology continue to push into the pediatric market. In the near term, investor sentiment is more likely to track broader dupilumab sales trends and pipeline progress rather than this individual update.

The study record has been updated on ClinicalTrials, and while this particular trial is withdrawn, further details on dupilumab research remain available on the ClinicalTrials portal.

To learn more about SNY’s potential, visit the Sanofi SA drug pipeline page.