Dupixent CTCL Litigation
Court filings and medical literature have raised questions about certain Dupixent treatment histories followed by CTCL-related diagnoses, and those questions are still being reviewed.
This page explains the concern in patient-readable terms. It is focused on Dupixent and CTCL-related diagnoses, including mycosis fungoides and Sézary syndrome, rather than every cancer or every lymphoma.
This page is meant to help patients and families understand what has been reported, what has been alleged in litigation, what records may matter, and when it may make sense to request an initial review.
Multiple peer-reviewed studies and regulatory analyses have examined the association between Dupixent use and CTCL-related diagnoses. Key findings include:
The FDA identified CTCL as a potential signal of serious risk for dupilumab in its Q4 2024 FAERS report, published March 31, 2025. As of May 2026, CTCL has not been reflected in the Dupixent prescribing label.
Court filings and medical literature have raised questions about whether some Dupixent treatment histories were followed by CTCL or related T-cell lymphoma diagnoses.
According to the JPML motion and supporting brief, plaintiffs allege warning deficiencies and shared factual issues for coordinated pretrial review.
This page focuses on Dupixent and CTCL-related diagnoses. Individual review depends on a person’s treatment history, diagnosis records, timing, and other case-specific facts.
CTCL is a group of non-Hodgkin T-cell lymphomas that primarily involve the skin.
Mycosis fungoides and Sézary syndrome are commonly discussed CTCL diagnoses in this context, along with other related T-cell lymphoma diagnoses in the current review scope.
Because CTCL can present in different ways, patients and families often benefit from a clear timeline of symptoms, clinical visits, and pathology findings when requesting initial review.
In some histories, CTCL symptoms may overlap with eczema-like or other inflammatory skin conditions, which can make early recognition and diagnosis history more complex.
In some cases, diagnosis may require dermatology evaluation, biopsy/pathology findings, oncology review, or specialist interpretation over time.
For that reason, a clear timeline and available records can help reviewers understand how the diagnosis developed in a particular history.
A timeline can help reviewers understand whether Dupixent use came before diagnosis, whether symptoms changed during treatment, whether CTCL was suspected before or after Dupixent use, and whether pathology or specialist evaluation clarified the diagnosis.
A useful timeline may include:
These are review factors, not conclusions.
You do not need every document before starting, but these materials may help clarify whether an inquiry fits the current CTCL-focused review.
A simple written timeline can be helpful even before records are complete.
This page summarizes medical background, reported safety-signal discussions, and litigation allegations involving Dupixent and CTCL-related diagnoses. It does not make a medical diagnosis, and no court has made a final determination on the allegations.
Individual review depends on the person’s treatment history, diagnosis records, timing, pathology or specialist findings, and other case-specific facts.
You may consider requesting an initial review if you:
Submitting basic information can help the review team understand whether follow-up may be appropriate.
Last reviewed by Keke Feng, Esq. — June 9, 2026
CTCL refers to a group of T-cell lymphomas that primarily involve the skin, rather than every lymphoma category. In this page's scope, commonly discussed CTCL diagnoses include mycosis fungoides and Sézary syndrome.
Court filings, safety-signal discussions, and peer-reviewed medical literature have raised questions about some Dupixent treatment histories and later CTCL-related diagnoses. Reviewers look at timeline, diagnosis records, and whether the history appears to fit the current CTCL-focused review.
This review is focused on CTCL and related T-cell lymphoma diagnoses, including mycosis fungoides and Sézary syndrome. Other cancers or unrelated lymphoma diagnoses may involve different medical and legal questions.
This page summarizes reported medical literature, safety-signal discussions, and litigation allegations involving Dupixent and CTCL-related diagnoses. Individual review depends on the person’s treatment history, diagnosis records, timing, and other case-specific facts.
Helpful materials often include Dupixent treatment dates, dermatology and oncology records, pathology reports, diagnosis documentation, and a short symptom timeline. If records are incomplete, start with the dates and documents you already have.
Yes. You can begin with basic information and a timeline. Additional records may be requested later if the inquiry appears to warrant further review.
No. Submitting information requests an initial review only. It does not mean your matter has been accepted and does not create an attorney-client relationship.
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.