Lawsuit Claims Dupixent for Atopic Dermatitis, Eczema Treatment Caused CTCL

Complaint indicates that more than 200 Dupixent CTCL cases have been identified since the drug was approved in 2017.

A product liability lawsuit filed by a Florida man alleges that Dupixent caused a rare form of cancer, while also triggering flare-ups of the eczema it was prescribed to treat.

Michael Durkin filed the complaint (PDF) in the U.S. District Court for the Middle District of Florida on February 4, naming Sanofi-Aventis U.S. LLC and Regeneron Pharmaceuticals Inc. as the defendants. The lawsuit claims that the manufacturers failed to warn patients or the medical communities that Dupixent side effects could cause a rare form of lymphoma.

Federal regulators first approved Dupixent (dupilumab) in 2017 for the treatment of atopic dermatitis, a form of eczema. The label was later expanded, making it a treatment for asthma, chronic obstructive pulmonary disease (COPD) and other inflammatory diseases affecting the respiratory tract and skin.

Durkin is just one of more than a million patients who have received Dupixent since its approval. However, despite being marketed as safe and effective, Dupixent side effects have been linked to 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. These concerns have linked the medication with an increased risk of cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL).

In recent weeks and months, a growing number of individuals have begun filing Dupixent lawsuits nationwide, each involving similar claims that the manufacturers knew, or should have known, that Dupixent could increase CTCL and PTCL risks, yet chose to place profits over patients’ safety.

The new lawsuit indicates Durkin’s doctor prescribed Dupixent to treat chronic, recurrent dermatitis, which he had dealt with for eight years by using other types of treatments. He continued to receive the injections through at least October 2025.

“After brief improvement following the initial dose, Plaintiff’s skin condition persisted and later flared. By February 2024, while still on Dupixent, he reported a flare-up and developed new systemic symptoms including fatigue and joint pain.”

– Michael Durkin v. Sanofi-Aventis U.S. LLC et al

Durkin was diagnosed with cutaneous T-cell lymphoma (CTCL), Mycosis Fungoides type, in October 2025 after a biopsy of a lesion on his right forearm. He subsequently underwent phototherapy and topical steroid treatments, before being transitioned to Rinvoq in January 2026 following his cancer diagnosis.

According to the lawsuit, Durkin’s cancer could have been prevented if the manufacturers had adequately disclosed Dupixent’s cancer risks on the drug’s warning label. The complaint alleges that within approximately one year of Dupixent’s approval, the manufacturers had already received more than a dozen reports linking the drug to CTCL, a figure that grew to more than 200 reports by the end of 2024.

Durkin’s claims include failure to warn, negligence, breach of post-market duty to warn, negligent misrepresentation, breach of warranty, and violations of Florida’s Deceptive and Unfair Trade Practices Act, and he is seeking both compensatory and punitive damages.

Dupixent Cancer Lawsuits

The complaint joins a growing number of similar Dupixent lawsuits, raising allegations that the medication may be linked to diagnoses of CTCL, PTCL or other types of T-cell lymphoma.

Patients who used Dupixent and were later diagnosed with one of these illnesses may be eligible to pursue legal claims seeking compensation for their injuries and related losses.

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.