Can Dupixent Cause Cancer? What the Evidence Actually Shows

By Jack W. Lurton, III · Medical Malpractice and Mass Tort Attorney, Rafferty Domnick Cunningham & Yaffa, P.A.

Published July 18, 2026 · Last updated July 27, 2026

In Brief

Researchers have reported a link between Dupixent (dupilumab) and cutaneous T-cell lymphoma, a rare skin cancer. Several studies found roughly four-fold higher risk. At least one large study found no increased risk at all. The FDA has listed the issue as a potential safety signal but has not added a warning to the label, and the drug has not been recalled. In June 2026 the federal lawsuits were consolidated into one proceeding. None of that settles whether the drug causes the cancer.

When researchers start linking a widely used medicine to a rare disease, the hardest question is rarely whether anyone has filed a lawsuit. It is whether doctors, researchers, and patients are asking the same question, and what evidence will eventually answer it.

That is where Dupixent sits right now.

I have spent about thirty years reading pharmaceutical evidence for a living, usually on behalf of people who were hurt by a drug. That work has taught me something that cuts against my own professional interest: an early signal is not a conclusion. Sometimes it holds up and a company is held to account. Sometimes it dissolves under better data. With Dupixent and cutaneous T-cell lymphoma, we are still in the part of the story where honest people disagree.

So this is not a piece about a lawsuit. It is about what the evidence shows, what it does not, and where the courts have and have not gotten involved.

What Dupixent Is, and Why That Matters Here

Dupixent is an injectable biologic, generic name dupilumab, developed by Regeneron and Sanofi. The FDA approved it in March 2017 for adults with moderate-to-severe eczema (atopic dermatitis). Its approved uses have since expanded to include eczema in patients as young as six months, asthma, chronic rhinosinusitis with nasal polyps, eosinophilic esophagitis, and prurigo nodularis.

It is worth being clear about something coverage of drug litigation usually skips: for a lot of people this medication works, and works dramatically. Severe atopic dermatitis is not a cosmetic problem. It is relentless itching, broken skin, infection, and lost sleep, and the treatments that came before biologics carried real costs of their own. Any honest discussion of risk has to sit next to that benefit. A drug can be genuinely useful and still carry an under-studied risk. Pretending otherwise is how people end up making bad decisions about their own care.

What Cutaneous T-cell Lymphoma Is, and How Common It Is

Cutaneous T-cell lymphoma, or CTCL, is a cancer of certain white blood cells that appears first in the skin. Its most common forms are mycosis fungoides and Sézary syndrome. It can be difficult to treat, and in its advanced stages it is serious.

Two things about CTCL matter for everything that follows.

First, it is genuinely rare. An analysis of U.S. cancer-registry data from 2000 to 2018, drawn from the National Cancer Institute’s SEER program, put the overall CTCL rate at roughly 8.6 cases per million people per year, with mycosis fungoides making up about 5.4 of those. That figure describes the general population rather than people with atopic dermatitis, so treat it as a rough floor and not as your own number.

It is worth knowing anyway, because the studies below report relative risk: how much more often something happens in one group than another. Several times a very small number is still a small number. None of those studies published an absolute risk figure I would ask a patient to rely on. Be skeptical of anyone who quotes you a multiplier without telling you what it multiplies.

Second, early CTCL looks a great deal like eczema. It is frequently mistaken for it, sometimes for years. Hold onto that, because it turns out to be the center of the entire scientific dispute.

What the Evidence Shows

Start with the study that put this question on the map.

In 2024, Hasan and colleagues published a retrospective cohort in the Journal of the American Academy of Dermatology, drawing on the TriNetX health-records database. Among eczema patients treated with dupilumab, the odds of a CTCL diagnosis came out roughly four times higher than among eczema patients who had never taken it. Most of those diagnoses arrived more than a year after the first injection. The authors were careful about what they had shown: an association, not proof of cause.

Two other findings point the same direction. A second 2024 cohort, from Mandel and colleagues in Dermatologic Therapy, landed at almost exactly the same magnitude. And a separate analysis in the Journal of Investigative Dermatology combed FDA adverse-event reports and found CTCL turning up alongside dupilumab far more often than the background rate would predict.

One detail in that last analysis deserves more attention than it usually gets. The signal was specific. CTCL stood out; other lymphomas did not. A drug that broadly caused blood cancers would not be expected to leave a fingerprint that narrow, and that specificity is much of why this question has been taken seriously instead of waved off.

Now the part most articles on this subject leave out.

In 2026, Kridin and colleagues published a large cohort study in Frontiers in Medicine using insurance-claims data across matched groups of thousands of patients, and reached a different conclusion. Their central finding is the one I would want any patient to understand: atopic dermatitis by itself carries an elevated risk of lymphoma, with no drug involved at all. And when the study compared dupilumab against other systemic treatments for the same disease, dupilumab did not raise lymphoma risk. In some analyses it trended lower.

That reframes everything above it. If the underlying condition already elevates lymphoma risk, then finding more lymphoma among the people treated for that condition does not, on its own, tell you the treatment caused it. It may only tell you that the sickest patients receive the strongest drugs.

One more piece belongs on that side of the ledger. In the three pivotal clinical trials behind Dupixent’s original approval, no participant was diagnosed with lymphoma. Those trials were neither long enough nor large enough to catch something this rare, so the result proves less than it first appears. It is still not nothing.

The Question Nobody has Answered Yet

Because early CTCL is so often mistaken for eczema, some patients prescribed Dupixent may have already had the lymphoma before their first injection. On that reading, the drug is not causing the cancer. It is revealing one that was already there, either because a treatment for eczema does nothing for skin that was never eczema, or because that failure finally prompts someone to order a biopsy.

Researchers call this the unmasking hypothesis, and it belongs to neither side. Defense commentary uses it to argue the whole association is an artifact of misdiagnosis. But mechanistic work in the Journal of Allergy and Clinical Immunology suggests that by altering IL-13 and IL-4 signaling, the drug could let an existing population of malignant cells progress faster than it otherwise would.

Revealing a cancer and accelerating one are different things. The distance between them is worth a great deal to both sides, and no one has closed it yet. Anyone who tells you otherwise, in either direction, is selling something.

Where the FDA Stands

In its October–December 2024 quarterly FAERS report, posted in early 2025, the FDA listed cutaneous T-cell lymphoma as a potential signal of a serious risk associated with Dupixent, and said it was evaluating the need for regulatory action.

That is a real step, and a modest one. It means the agency saw enough in the adverse-event data to look harder. It does not mean the agency reached a conclusion.

What has not happened matters just as much. The current FDA-approved label carries no lymphoma or malignancy warning. The drug has not been recalled. It remains approved, widely prescribed, and the agency has continued to clear it for new uses.

If You are Taking Dupixent Right Now

Talk to your dermatologist. That is the entire recommendation, and it comes before anything a lawyer tells you.

Do not stop taking a prescribed medication because you read an article. Stopping carries its own risks, and for severe atopic dermatitis those risks are not theoretical. This is a conversation for the physician who knows your skin, your history, and your alternatives.

A few questions tend to make that conversation more useful. Has the skin diagnosed as eczema ever been biopsied? Is there anything about how my disease has behaved, or failed to respond, that would make a second look worthwhile? Given my age and history, how do you weigh this signal against what this drug is doing for me?

Those are medical questions. They belong to your doctor, not to me.

Where the Litigation Stands

The legal system has now gotten involved, and it is worth describing precisely, because this is where coverage tends to overreach.

On June 4, 2026, the U.S. Judicial Panel on Multidistrict Litigation gathered the federal Dupixent cases into a single proceeding: In re: Dupixent (Dupilumab) Products Liability Litigation, MDL No. 3180. It sits in the District of New Jersey, before Judge Zahid N. Quraishi. Fifteen cases from twelve federal districts moved into it, with seven more flagged as likely to follow. The named defendants are Regeneron Pharmaceuticals, Sanofi-Aventis U.S. LLC, and Genzyme Corporation.

The venue itself was fought over. Plaintiffs wanted Georgia, the manufacturers wanted New York, and the Panel chose New Jersey. Nobody argues that hard about a courtroom for a case they expect to fizzle.

Consolidation then gets misread, reliably, in two ways.

An MDL is not a class action. Each person keeps an individual case. They share a judge and a pretrial process for efficiency, and each one still rises or falls on its own facts.

An MDL is not evidence. Consolidation is an administrative decision that a group of lawsuits raises overlapping questions. It is not a finding that the drug causes cancer, and it is not a ruling on the science. Treating the existence of a lawsuit as proof of the claim inside it is exactly the error this area invites. What these cases allege is that the manufacturers failed to adequately warn about a lymphoma risk. Allegations are not findings.

Who These Cases Actually Involve

The lawsuits concern a specific group: people who took Dupixent and were later diagnosed with cutaneous T-cell lymphoma, including mycosis fungoides and Sézary syndrome, and the families of those who died from it.

I want to be precise about that, because the drift in this field is predictable. A piece starts by describing patients with a particular cancer and ends by inviting anyone who ever took the medication to call. Having taken Dupixent is not an injury. If you took the drug and you are well, there is nothing here for you, and you should be wary of anyone suggesting otherwise.

If you were diagnosed with CTCL after taking Dupixent, the questions a lawyer would actually put to your records are narrow and factual. What were you prescribed, and when. When did the diagnosis come. What did the biopsies show, and was there an earlier one that got read as something else.

In a pharmaceutical case, the timeline is most of the case. Filing deadlines vary by state and by the circumstances of the diagnosis, and they are less forgiving than most people expect.

Frequently Asked Questions

Can Dupixent cause cancer?

No one can answer that yet. Several studies report roughly four-fold higher odds of cutaneous T-cell lymphoma in dupilumab-treated patients. At least one large study found no increased risk and suggested the underlying eczema explains much of the association. The FDA is evaluating the question. The label carries no lymphoma warning and the drug has not been recalled.

Should I stop taking Dupixent?

Not on the strength of anything you read here. That decision belongs to you and your dermatologist, who can weigh this against what the medication is doing for your disease and what your alternatives are.

Is this a class action?

No. It is a multidistrict litigation, MDL No. 3180 in New Jersey, where individual cases are coordinated for pretrial purposes but remain individual cases.

Does the MDL mean the drug has been proven dangerous?

No. Consolidation is a case-management decision about efficiency. The underlying allegations still have to be proven.

My eczema was never biopsied. Does that matter?

It might, and it is worth raising with your dermatologist. Because early CTCL and eczema can look alike, whether and when tissue was examined is often the most informative part of the record, medically and legally.

Why Bring a Case Like This to Our Firm

Most firms advertising for drug cases refer them elsewhere. We try them. Our attorneys have held leadership positions in national pharmaceutical litigation, and I currently serve on the Plaintiffs’ Executive Committee in the Depo-Provera litigation.

What that experience mostly buys, in a case at this stage, is judgment about which claims are real. The science here is unsettled, and I would rather tell someone their case is difficult than sign them up and let them find out later. If you were diagnosed with cutaneous T-cell lymphoma after taking Dupixent and you want an honest read on where you stand, contact Rafferty Domnick Cunningham & Yaffa or call (561) 516-5168. There is no charge to ask, and you will get a straight answer.

About the Author

Jack W. Lurton, III is a distinguished medical malpractice and mass tort attorney at Raffety Domnick Cunningham & Yaffa, bringing over 22 years of experience in civil litigation. Jack has tried medical malpractice, personal injury, wrongful death, and products liability cases in Florida, Alabama, and New Jersey, earning a reputation for his exceptional trial advocacy and results-driven approach. Raised in Pensacola, Jack has represented both plaintiffs and defendants in complex cases, including extensive jury trial experience in Pensacola and Panama City, Florida. Read Jack’s full profile.

This article is general information, not legal or medical advice. Dupixent is an FDA-approved medication and this article does not recommend for or against taking it. Do not start or stop any prescribed treatment without talking to your physician. Reading this page does not create an attorney-client relationship. Past results do not guarantee future outcomes.

Sources

Hasan I, et al. “Dupilumab therapy for atopic dermatitis is associated with increased risk of cutaneous T cell lymphoma: A retrospective cohort study.” Journal of the American Academy of Dermatology, 2024. OR 4.1003 (95% CI 2.055–8.192), TriNetX.
Mandel J, et al. “Increased Risk of Cutaneous T-Cell Lymphoma Development after Dupilumab Use for Atopic Dermatitis.” Dermatologic Therapy, 2024. RR 4.59 (95% CI 2.459–8.567).
FAERS disproportionality analysis, Journal of Investigative Dermatology, 2024. CTCL ROR 8.81 (7.1–10.9) monotherapy; 10.35 (8.5–12.6) polytherapy; non-CTCL lymphoma ROR 0.44.
Kridin K, et al. “Dupilumab treatment is not associated with changes in lymphoma risk in atopic dermatitis and other type 2 inflammatory diseases.” Frontiers in Medicine, 2026;12:1702736.
Cabrera-Perez JS, et al. “Integrative epidemiology and immunotranscriptomics uncover a risk and potential mechanism for cutaneous lymphoma unmasking or progression with dupilumab therapy.” Journal of Allergy and Clinical Immunology.
U.S. FDA, “October–December 2024 | Potential Signals of Serious Risks / New Safety Information Identified by FAERS,” posted early 2025.
U.S. FDA, Dupixent prescribing information (2025 and 2026 label versions), accessdata.fda.gov.
JPML, Transfer Order, In re: Dupixent (Dupilumab) Products Liability Litigation, MDL No. 3180, Doc. 47, filed June 4, 2026.
“Incidence Trends of Primary Cutaneous T-Cell Lymphoma in the US From 2000 to 2018: A SEER Population Data Analysis,” 2022. Overall CTCL 8.55 per million; mycosis fungoides 5.42 per million. (NCI SEER, 18 registries.)