4/1/2026
Dupixent Linked to Cutaneous T‑Cell Lymphoma
A motion for consolidation was filed on February 13, 2026 with the Joint Panel on Multidistrict Litigation (JPML) on behalf of 15 plaintiffs who have filed lawsuits in 12 district courts alleging they developed cutaneous T-cell lymphoma (CTCL), a rare form of non-Hodgkin lymphoma, after taking the prescription biologic medication Dupixent (dupilumab). The lawsuits claim that the drug’s manufacturers, Regeneron Pharmaceuticals, Inc. and Sanofi-Aventis U.S. LLC knew about the possible connection between the drug’s immune suppressing mechanism and the development, obscuring or accelerating the progression of T-cell lymphoma but failed to warn patients and health care providers. Dupixent is used to treat atopic dermatitis/eczema, COPD, asthma and a variety of other inflammatory conditions; it works by targeting the immune pathways involved in allergic inflammation. The predominant subtypes of CTCL are mycosis fungoides and Sezary syndrome (an aggressive form of CTCL).
Plaintiffs Cite Epidemiological Studies in Motion to Transfer
“Recent epidemiological studies have shown a strong association between the usage of Dupixent and the development of T-cell lymphomas. Specifically, an analytical cohort study published in the Journal of the American Academy of Dermatology in 2024 found that Dupixent patients exhibited over a 300% increased risk of developing cutaneous T-cell lymphoma (“CTCL”) compared to untreated subjects.3 Another analytical cohort study published in June 2025 in the European Respiratory Journal found a nearly 400% increased risk of T-cell and NKcell lymphomas among asthma patients taking Dupixent as compared to those taking inhaled corticosteroids or long-acting beta agonists.4 This study also observed similar increases in risk (450-500%) for various T-cell lymphoma subtypes, including CTCL, peripheral T-cell lymphoma and Mycosis fungoides/Sézary syndrome. In total, to date seven epidemiologic studies have reported a strong and consistent increased risk of T-cell lymphomas with the use of Dupixent. These studies follow years of other literature reflecting that Dupixent use is involved in the development of T-cell lymphomas.”
The motion requests that the court transfer the cases to the U.S. District Court for the Northern District of Georgia because 25% of the cases are filed in the district which is centrally located and possessed of the necessary judicial resources to adequately administer the litigation.
