Dupixent Caused T-Cell Lymphoma or Rapidly Progressed Cancer, Lawsuit Alleges

Lawsuit alleges that Dupixent side effects not only worsened the eczema it was prescribed to treat, but also contributed to the development of late-stage CTCL.

According to a newly filed lawsuit, a Nevada man indicates he developed a rare form of cancer from Dupixent side effects less than a year after beginning treatment with the eczema drug.

David Luchsinger and his wife, Cheryl, brought the complaint (PDF) in the U.S. District Court for the District of Nevada on February 10, pursuing damages from Regeneron Pharmaceuticals Inc. and Sanofi-Aventis U.S. LLC, arguing that the drug makers should be held liable for failing to warn about known cancer risks associated with Dupixent.

Dupixent Cancer Risks

Dupixent (dupilumab) is a treatment approved for atopic dermatitis, a form of eczema, as well as for asthma, chronic obstructive pulmonary disease (COPD) and other inflammatory diseases affecting the respiratory tract and skin.

First approved in 2017, Dupixent has been given to more than 1 million patients. However, recent studies have suggested that Dupixent side effects may cause the development or progression of T-cell lymphoma, a rare form of cancer that impacts the body’s white blood cells, which are a key part of the immune system. Studies have linked the drug to an increased risk of cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL).

The Luchsingers’ complaint now joins a growing number Dupixent cancer lawsuits being pursued nationwide, each involving similar allegations that the manufacturers knew, or should have known, about the drug’s cancer risks, yet failed to provide adequate warnings to the medical community or patients.

In the lawsuit, David Luchsinger indicates that he began receiving Dupixent injections in October 2024, and continued to receive them until March 2025, after being diagnosed with eczema. Before the injections, he had never been diagnosed with any form of lymphoma.

After five months of Dupixent injections, Luchsinger’s eczema allegedly worsened. About a year after beginning treatment, in October 2025, he was diagnosed with a form of cutaneous T-cell lymphoma known as mycosis fungoides, which the lawsuit claims was caused by Dupixent side effects.

According to the complaint, continued injections contributed to a rapid progression of the disease, and the cancer was not identified until it had advanced to a late stage.

Luchsinger states that the manufacturers failed to conduct adequate testing of Dupixent before it was placed on the market, failed to supply adequate warnings to users, and intentionally downplayed the risks to ensure profits rather than patient safety. In addition, the lawsuit indicates that the manufacturers knew that doctors should monitor patients for the development of T-cell lymphoma, yet failed to pass that information on to the medical community.

“Despite the fact that peer-reviewed case reports, case series, epidemiologic articles and studies emerged providing evidence of the carcinogenic dangers of Dupixent, Defendants failed to adequately test Dupixent to investigate the risks, including the potential of exacerbating or accelerating the progression of pre-existing T-cell lymphoma or increasing susceptibility to its development.”

– David Luchsinger et al. v. Regeneron Pharmaceuticals Inc. et al

The lawsuit describes Luchsinger’s prognosis as “grim.”

The couple presents claims of failure to warn, negligence and loss of consortium. They seek both compensatory and punitive damages.

Dupixent Cancer Lawsuits

Due to common questions of fact and law raised in similar complaints now being pursued throughout the federal court system, several plaintiffs have petitioned the U.S. Judicial Panel on Multidistrict Litigation (JPML) to consolidate all Dupixent cancer lawsuits before one U.S. District Judge in the Northern District of Georgia, as part of an MDL, or multidistrict litigation.

If centralization is established, the lawsuit filed by the Luchsingers and other plaintiffs will be coordinated for discovery and pretrial proceedings, as we as a result of early bellwether trials to gauge how juries may respond to evidence and testimony likely to be repeated throughout the litigation. However, each case would remain an individual lawsuit, and plaintiffs would retain their own counsel to prove that their injuries were directly caused by the medication’s side effects.

Dupixent lawyers provide no-cost consultations to review medical records, discuss possible claims and determine whether individuals may be eligible for a Dupixent lawsuit settlement. These claims are handled on a contingency basis, meaning there are no upfront legal costs and attorney fees are only paid if a settlement or verdict is obtained.

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