Dupixent (dupilumab) is a widely prescribed injectable medication that has provided relief for hundreds of thousands of people suffering from chronic inflammatory conditions like severe atopic dermatitis (eczema), asthma, and nasal polyps. For many, it has been a life-changing treatment.
However, a growing body of scientific evidence and regulatory scrutiny has raised serious safety concerns, linking Dupixent to an increased risk of rare but aggressive forms of cancer known as T-cell lymphomas.
As a result, individuals across the country who were diagnosed with lymphoma after using Dupixent are now filing lawsuits against its manufacturers, Sanofi-Aventis U.S. LLC and Regeneron Pharmaceuticals, Inc. These legal claims allege that the companies knew, or should have known, about the potential cancer risk but failed to adequately warn patients and the medical community, prioritizing profits over patient safety.
A recent wrongful death lawsuit filed in October 2025 highlights the devastating consequences alleged in these cases. The suit was filed by the daughter of a Tennessee woman who was prescribed Dupixent for adult-onset atopic dermatitis in May 2024. After only two months of injections, her condition did not improve, and she was later diagnosed with aggressive Peripheral T-cell Lymphoma (PTCL). She passed away in October 2024. The lawsuit alleges Dupixent caused or accelerated her cancer, leading to her tragic and untimely death.
If you or a loved one used Dupixent and were later diagnosed with a T-cell lymphoma, this page provides important information about the scientific evidence, legal allegations, and your right to seek compensation.
What are T-Cell Lymphomas?
T-cell lymphomas are a rare group of non-Hodgkin lymphomas that originate in the T-cells, a type of white blood cell that plays a crucial role in the immune system. In these cancers, the immune cells become malignant. The Dupixent lawsuits involve several types of T-cell lymphoma, including:
- Cutaneous T-cell Lymphoma (CTCL): This is the most common type linked to Dupixent, where the cancerous T-cells pathologically attack the skin. The two most prevalent subtypes are Mycosis Fungoides and the more aggressive Sézary Syndrome.
- Peripheral T-cell Lymphoma (PTCL): This refers to a group of more systemic T-cell lymphomas that can be found in the lymph nodes, blood, and other organs, and may also involve the skin.
A significant challenge with these cancers, particularly CTCL, is that their early symptoms (such as red, scaly, and intensely itchy patches of skin) can be nearly indistinguishable from common skin conditions like eczema. This similarity can lead to misdiagnosis for years before the actual cause is identified.
The Scientific Evidence Linking Dupixent to T-Cell Lymphoma
A series of recent, peer-reviewed medical studies have identified a strong, statistically significant link between the drug and an increased risk of T-cell lymphomas.
Studies published in 2024 in prominent journals, including JAMA Dermatology, found that patients with atopic dermatitis treated with Dupixent had a risk of developing CTCL that was between three and four-and-a-half times higher than those not on the drug.
A 2025 study in the European Respiratory Journal was particularly significant. It found that asthma patients using Dupixent had a 4.5-fold increased risk of mature T-cell lymphomas. This finding is critical because it suggests the risk is tied to the drug itself, not the underlying skin disease it is often prescribed to treat.
Analyses of safety databases from the FDA (FAERS) and the World Health Organization (VigiBase) have also revealed strong safety signals, with one analysis finding an eleven-fold statistically significant increase in the odds of CTCL with Dupixent use.
These findings are further supported by regulatory action. After receiving hundreds of reports of lymphoma in Dupixent users, the U.S. Food and Drug Administration (FDA) has placed the drug on its quarterly list of medications with “Potential Signals of Serious Risks” for CTCL and confirmed that it is formally investigating the link and the need for regulatory action.
Allegations in Dupixent Lawsuits
The legal claims against Sanofi and Regeneron include strict liability, negligence, and misrepresentation. The core allegations are:
- Failure to Warn: Lawsuits claim the manufacturers failed to update Dupixent’s warning label to include the risk of CTCL and PTCL, thereby depriving doctors and patients of the ability to make an informed decision about the drug’s benefits and risks. The U.S. label for Dupixent does not mention these risks.
- Failure to Instruct Doctors: The lawsuits allege a specific failure to warn physicians that CTCL should be ruled out before starting Dupixent, especially in patients with atypical presentations like adult-onset atopic dermatitis.
- Diagnostic Masking: Because Dupixent works by suppressing the inflammatory skin symptoms that are the primary signs of early-stage CTCL, lawsuits allege that the drug can hide or “mask” the cancer’s progression. A patient and their doctor may believe the drug is effectively treating eczema, while in reality, an underlying lymphoma is advancing to a more dangerous stage.
- Negligent Misrepresentation: Lawsuits claim that the companies made misleading statements in their marketing, using slogans like “heal your skin from within,” which promoted the drug as safe and effective while concealing its serious cancer risks.
Do You Qualify for a Dupixent Lawsuit?
Our drug injury attorneys are currently investigating claims on behalf of individuals nationwide. You may be eligible to file a Dupixent lawsuit if you or a loved one:
- Were prescribed and used Dupixent injections for any approved condition.
- Were subsequently diagnosed with Cutaneous T-cell Lymphoma (CTCL), Peripheral T-cell Lymphoma (PTCL), Mycosis Fungoides, or Sézary Syndrome.
- Were not diagnosed with any form of lymphoma or leukemia before starting Dupixent treatment.
- Are within your state’s statute of limitations, or legal deadline, for filing a claim.
In cases where a loved one passed away from complications of T-cell lymphoma after using Dupixent, the family may be able to file a wrongful death lawsuit to seek justice.
What Can You Recover?
A diagnosis of cancer is a life-altering event that brings immense physical, emotional, and financial burdens. A successful Dupixent lawsuit can provide compensation for damages, including:
- Past and future medical expenses for cancer treatment and monitoring.
- Lost wages and loss of future earning capacity.
- Pain, suffering, and emotional distress.
- Loss of quality of life.
- Wrongful death damages for surviving family members, such as loss of companionship and funeral expenses.
Pharmaceutical companies have a duty to ensure their products are safe and to provide adequate warnings about all known risks. When they fail in this duty, they must be held accountable.
How We Can Help
If you or a family member developed T-cell lymphoma after using Dupixent, we’d like to hear from you.
Reach out through our website for a confidential conversation about what happened. This initial consultation is provided at no cost and with no obligation. We’ll review the facts of your case, explain how the law applies to your situation, and give you an honest assessment.
As a boutique firm, we don’t take every case that comes through the door. We carefully evaluate each potential matter to ensure we can provide the focused attention and resources necessary to achieve the best possible outcome. If your case is one we believe in, we’ll explain your legal options and guide you through the next steps.
One thing we’ll address up front is timing. The law allows only a certain window to file claims like these, and that window varies by state and circumstance. We’ll tell you exactly where you stand and what needs to happen next.
Our firm takes these cases on contingency, which means we don’t get paid unless you do. We’re willing to invest our time and resources because we believe in holding these companies accountable when their products cause harm.
