Dupixent and Sézary Syndrome Lawsuit Review

This page is for people who used Dupixent and were later diagnosed with Sézary syndrome, CTCL, mycosis fungoides, PTCL, or another related T-cell lymphoma. It explains, in plain English, why diagnosis timing, treatment history, and records may matter during an initial review.

What is Sézary syndrome?

Sézary syndrome is a serious form of cutaneous T-cell lymphoma (CTCL). In general terms, it can involve skin symptoms and abnormal malignant T cells.

Because Sézary syndrome can involve complex medical evaluation, patients and families may need dermatology, pathology, oncology, and related records to understand how the diagnosis was reached.

Why might Sézary syndrome matter in a Dupixent CTCL review?

Dupixent lawsuits and case reviews are looking at certain histories where Dupixent use was followed by CTCL-related diagnoses. Review may focus on diagnosis timing, skin symptom history, treatment response, pathology or oncology records, and whether the condition may have been difficult to recognize earlier.

No court has made a final determination on the allegations involving Dupixent, Sézary syndrome, CTCL, or any related T-cell lymphoma.

For broader background, read Dupixent and Sézary syndrome, Dupixent Lawsuit Overview, and Dupixent MDL No. 3180 updates.

What case review factors may matter?

  • Whether Dupixent was used and when treatment began
  • Why Dupixent was prescribed
  • When skin symptoms began, worsened, changed, or failed to respond
  • Whether Sézary syndrome, CTCL, mycosis fungoides, PTCL, or another T-cell lymphoma was diagnosed
  • Diagnosis date
  • Dermatology, biopsy, pathology, oncology, and blood-test-related records if available
  • Whether another attorney already represents the matter
  • State where treatment or diagnosis occurred

What records should patients keep?

  • Dupixent prescription/pharmacy history
  • Dermatology visit history
  • Biopsy/pathology reports
  • Oncology notes
  • Blood test or specialist records if related to the diagnosis
  • Diagnosis records
  • Photos of skin progression, if available
  • Treatment timeline

You do not need to have every record before asking for an initial review. Basic information about diagnosis, timing, treatment history, and state may help determine whether follow-up is appropriate.

Sources reviewed

  • JPML and court materials
  • Dupixent prescribing information
  • FDA and safety materials
  • Peer-reviewed medical literature regarding Dupixent, CTCL, and Sézary syndrome

Last reviewed: May 22, 2026

Start Free Case Review

If you used Dupixent and were later diagnosed with Sézary syndrome, CTCL, or another T-cell lymphoma, you can submit basic information for an initial review.

Call 888-271-9175 Start Free Case Review