Failure to warn
Plaintiffs allege that Dupixent labeling did not adequately warn patients or doctors about reported CTCL risks.
Dupixent CTCL Litigation
Dupixent Lawsuit: CTCL Claims & MDL 3180
Lawsuits involving Dupixent allege that patients and doctors were not adequately warned about reported CTCL risks. This page explains the current litigation posture, the core allegations, and what an initial case review may consider.
What is the Dupixent lawsuit about?
The Dupixent litigation focuses on allegations involving CTCL diagnoses after Dupixent use and claims that the drug's labeling did not adequately warn about reported CTCL risks. Filed JPML materials describe allegations involving warnings, labeling, marketing, safety-signal context, and related common issues.
This page provides general litigation background. Individual medical history, diagnosis records, timing, and other facts still need case-specific review. For science-focused background, see Dupixent & CTCL.
Current litigation status
Last reviewed August 17, 2026
The JPML’s June 4, 2026 Transfer Order created MDL No. 3180, centralized the listed actions in the District of New Jersey, and transferred the actions pending outside that district for coordinated pretrial proceedings. For the latest verified litigation developments, see Dupixent litigation updates.
For a plain-English explanation of the procedural development, read what MDL No. 3180 may mean for patients diagnosed with CTCL.
Who are the defendants in the Dupixent litigation?
Filed JPML materials identify Regeneron Pharmaceuticals, Sanofi-Aventis U.S. LLC, and Genzyme Corporation in the litigation context. These descriptions summarize allegations and procedural background from filed materials and should not be read as findings by a court.
For related medical background, visit Dupixent & CTCL.
What do plaintiffs allege?
Scientific and safety signals
Filed materials reference published studies, adverse-event data, and regulatory reporting that plaintiffs say raised questions about CTCL-related risks.
Marketing and labeling
Plaintiffs allege that defendants promoted Dupixent across approved uses while failing to provide adequate warnings about reported CTCL risks.
Common factual questions
The JPML motion and supporting brief describe common factual and legal questions across the actions.
What diagnoses may be relevant to this review?
MDL No. 3180 currently focuses on CTCL and CTCL subtypes. Mycosis fungoides and Sézary syndrome are common types of CTCL. The JPML has not decided whether other, non-cutaneous T-cell lymphomas belong in the MDL; the Transfer Order states that possible future expansion may be addressed through conditional transfer proceedings. Other cancers and lymphoma diagnoses may involve different medical and legal questions.
If your records include a CTCL diagnosis after Dupixent use, your history may warrant review through the initial review form.
Does Dupixent cause cancer?
This site addresses allegations involving CTCL, not a general claim that Dupixent causes cancer. MDL centralization is a procedural decision and does not establish that Dupixent caused CTCL or any other condition. The FDA’s potential-signal listing likewise does not establish causation.
FDA CTCL safety-signal clarification
FDA’s October–December 2024 potential-signal report, published with information as of March 6, 2025, identifies CTCL for Dupixent as a potential safety signal under FDA evaluation. FDA’s listing is not a finding that Dupixent causes CTCL. See the FDA safety-signal page and the current FDA prescribing information.
What may matter in an initial review?
An initial review may consider whether the person used Dupixent, the approved indication for which it was prescribed, the diagnosis received, the timing between treatment and diagnosis, whether medical records show a delayed diagnosis, worsening symptoms, progression, or specialist evaluation, and whether pathology or specialist records are available.
These facts can help reviewers understand whether a history may warrant closer review. You can start with basic details at the initial review form.
Sources reviewed for this page
- JPML Transfer Order, In re: Dupixent (Dupilumab) Products Liability Litigation, MDL No. 3180, filed June 4, 2026.
- FDA potential-signal report for October–December 2024, listing CTCL for Dupixent under FDA evaluation.
- DailyMed/FDA prescribing information for DUPIXENT® (dupilumab), revised April 2026.
- National Cancer Institute, Mycosis Fungoides (Including Sézary Syndrome) Treatment (PDQ®).
- U.S. District Court MDL FAQ: Is multidistrict litigation a type of class action?
Helpful next pages
Dupixent & CTCL
Learn the scientific and medical background behind the CTCL-focused review.
Read Dupixent & CTCLDo I Qualify?
Review the basic facts that may matter before submitting an inquiry.
Read Do I Qualify?Initial Review
Submit basic information for an initial review.
Start Free Case ReviewLast reviewed by Keke Feng, Esq. — August 17, 2026
Frequently Asked Questions
Is there a Dupixent MDL?
Yes. On June 4, 2026, the JPML granted centralization for federal Dupixent cases involving alleged CTCL. The litigation is now proceeding as MDL No. 3180 in the District of New Jersey before Judge Zahid N. Quraishi.
What is the lawsuit alleging?
Plaintiffs allege failure-to-warn and related claims involving reported CTCL risks, with allegations tied to safety data, labeling, and marketing issues described in filed court materials.
Does this lawsuit cover every cancer after Dupixent?
No. MDL No. 3180 currently focuses on CTCL and CTCL subtypes, not every cancer or every lymphoma diagnosis.
Is the Dupixent litigation a class action?
No. MDL No. 3180 is multidistrict litigation, not a certified class action. The JPML transfer order coordinates related federal cases for pretrial proceedings; it does not establish liability or decide any individual claim.
Who are the defendants named in filed JPML materials?
Filed JPML materials identify Regeneron Pharmaceuticals, Sanofi-Aventis U.S. LLC, and Genzyme Corporation in the litigation context. These references summarize filed allegations and procedural materials and should not be read as findings by a court.
What information may help an initial review?
Helpful information may include Dupixent treatment history, diagnosis records, and timeline details about symptoms and confirmation of a CTCL-related diagnosis.
Does submitting a case review form mean my case has been accepted?
No. Submitting a form requests an initial review only and does not create an attorney-client relationship or mean a matter has been accepted.
Start Free Case Review
If you used Dupixent and were later diagnosed with CTCL or another related T-cell lymphoma, you may submit basic information for a focused initial review. You do not need to have every record ready before starting, although additional records may be needed later.