Drug Makers Must Respond to Dupixent Lawsuit Over Lymphoma Diagnosis by Jan. 7, 2026

An initial case management conference is scheduled early this month, in what is expected to be the first of many Dupixent lymphoma lawsuits that may be filed by users in the coming months and years.

A federal judge has granted the makers of Dupixent until early next year to respond to a recently filed wrongful death lawsuit, due to the complex scientific issues at stake, which allege that side effects of the treatment caused a woman to develop T-cell lymphoma.

Dupixent (dupilumab) was approved in 2017 as a treatment for various diseases that affect the skin and respiratory system, including inflammation and asthma. Patients are given injections of the drug every two to four weeks, and it has grown to become a top selling drug in recent years.

Although it has been marketed as a safe and effective treatment options, concerns have emerged about a link between Dupixent and T-cell lymphoma, a rare form of cancer that affects white blood cells. Specifically, Dupixent has been linked to increased risks of cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL).

In early October, Chandra Richardson of Tennessee filed a wrongful death lawsuit against Dupixent manufacturers Regeneron and Sanofi-Aventis, alleging that her mother, Cynthia Hyde, developed PTCL after receiving Dupixent injections. Hyde was diagnosed with adult-onset atopic dermatitis in 2019, and began Dupixent treatment in May 2024 before passing away in late October 2024.

On November 7, the manufacturers filed a motion (PDF) in the U.S. District Court for the Middle District of Tennessee, asking the Court for additional time to respond to Richardson’s complaint.

Regeneron and Sanofi-Aventis noted that they had not received notice of the lawsuit until late October, requesting that they be given until January 7 to file a response. They argued that Richardson’s lawsuit “includes exceptionally detailed and complex allegations and raises equally complex legal issues.”

In an order (PDF) issued on November 10, Magistrate Judge Alistair Newbern granted the request and gave the defendants until January 7 to file a response. That deadline falls 30 days after the initial case management conference currently set for December 8.

The initial Dupixent lawsuit status conference will be overseen by Judge Newbern, who will discuss with the parties the scheduling of key dates and deadlines in the litigation, as well as the potential trial. The notice also called on the parties to propose an initial case management order no later than three business days before the December 8 conference.

Dupixent Lawsuits

Richardson’s wrongful death claim is one of the first of what is expected to quickly become many Dupixent lawsuits, as more former users and families learn that the widely marketed treatment may be responsible for causing or accelerating the development of T-cell lymphoma.

The early management of this case could play an important role in how the litigation moves forward in other claims, which are likely to raise similar allegations that the drug makers knew or should have known about the Dupixent lymphoma risks, yet put a desire for profits before the health and safety of users by withholding warnings from both consumers and the medical community.

Law firms are now investigating complaints like Richardson’s for individuals who were prescribed the drug for any of its approved uses and later diagnosed with CTCL, PTCL or another T-cell lymphoma subtype. To receive a free consultation to determine if you or a loved one may be eligible to file a lawsuit, submit information for review by a Dupixent lawyer.