Sanofi and Regeneron Expand Dupilumab’s Real-World Footprint in Chronic Urticaria

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

Study Overview: Sanofi and Regeneron have launched a prospective observational study titled “A Prospective Observational Study of Patients Receiving Dupilumab for Chronic Spontaneous Urticaria.” The goal is to track how dupilumab performs in everyday medical practice for people with chronic spontaneous urticaria, focusing on real-world effectiveness, safety, and how the drug is used over time. This matters for investors because real-world data can confirm, refine, or challenge expectations set by earlier controlled trials, and can influence long-term demand and payer coverage.

Intervention/Treatment: The study follows patients who receive dupilumab, a drug already used for several inflammatory conditions, now being used for chronic spontaneous urticaria. The study does not give treatment itself; instead, it observes patients whose own doctors have already prescribed dupilumab as part of routine care. The aim is to understand how well the drug works, how safe it appears, and how patients use it over two years in normal clinical settings.

Study Design: This is an observational, cohort study with a prospective time frame. There is no random assignment and no comparison arm built into the design. Researchers simply follow a group of patients who are starting dupilumab and collect information from medical records and patient reports. There is no masking or blinding, and the main purpose is to describe outcomes in the real world rather than to prove cause and effect.

Study Timeline: The study is listed as “Not Yet Recruiting,” meaning enrollment has not started. The first submission to the registry was dated December 8, 2025, signaling when the sponsors formally recorded the plan. The latest update was submitted on January 2, 2026, which shows the protocol and operational details are active and being refined. Primary completion and final completion dates have not yet been reported, but each patient is expected to be followed for 24 months, so meaningful readouts will likely come a few years after enrollment begins.

Market Implications: For Sanofi and Regeneron, this study supports the strategic push to broaden dupilumab’s use beyond current indications and to strengthen its profile as a key anti-inflammatory franchise. Positive real-world data in chronic spontaneous urticaria could reinforce the drug’s value story with insurers, support label expansion efforts, and extend revenue durability, which would be supportive for REGN and SNY sentiment. In a competitive immunology space that includes biologics and newer targeted therapies from players like Novartis and Roche, credible real-world outcomes can help differentiate dupilumab on effectiveness, safety, and treatment persistence. While near-term stock impact may be limited due to the early stage and lack of results, the update signals continued pipeline investment and a focus on lifecycle management, which is generally viewed as a long-term positive by institutional investors.

The study is currently in the setup phase and remains ongoing as an updated entry on the ClinicalTrials portal, where further details and future results will be made available.

To learn more about REGN’s potential, visit the Regeneron Pharmaceuticals drug pipeline page.