Find Out If You Have a Case

Free, confidential review by Attorney Matthew T. Marin. Prefer to talk? Call (888) 348-2735.

Super Lawyers® 2014–2024CALL 24/7(888) 348-2735

Dupixent Lawsuit — Free, Confidential Case Review

Diagnosed with T-cell lymphoma after taking Dupixent?

A federal MDL is underway against Sanofi and Regeneron, the makers of Dupixent. Two confidential minutes tells you where you stand.

ACTIVE LITIGATION — NO SETTLEMENT. MDL 3180 underway · filing deadlines vary by state.

Were you — or someone you love — diagnosed with CTCL or another T-cell lymphoma after taking Dupixent?

Check if my case qualifiesfree · confidential · takes 2 minutes
I’m not sure of my exact diagnosis →

No documents needed · confidential · an answer either way · no fee unless there is a recovery. Court costs and litigation expenses are advanced by counsel and repaid from the recovery. You are not responsible for court costs or litigation expenses if there is no recovery, unless a court directs otherwise. The attorney’s fee is a percentage of the gross recovery, calculated before expenses are deducted.

Or talk to a person now: (888) 348-2735 — answered 24/7

Stefanie A. Murphy & Matthew T. Marin

Partners

Every Dupixent inquiry gets a personal review — and an honest answer either way, free and without obligation.

Claims are brought against Sanofi and Regeneron, the makers of Dupixent — not against your doctor. Conversations are confidential. Some matters may be referred to other lawyers. No settlement has been reached, and most cases are in their earliest stages; every case must be proven on its own facts. Attorney Advertising.

This page is about a lawsuit — it is not medical advice, and filing a claim does not require you to stop taking Dupixent. Decisions about your medication belong with you and your doctor.

As of September 15, 2026: at least 36 member actions identified in MDL 3180. See the member-case ledger on the MDL 3180 tracker.

Who Qualifies for the Dupixent Lawsuit?

The criteria are simpler than much of the advertising around this litigation suggests, and they come down to two facts: you took Dupixent, and you were diagnosed — during use or afterward — with cutaneous T-cell lymphoma or a related T-cell lymphoma. There is no minimum time on the drug. A diagnosis that followed three injections is evaluated the same way as one that followed three years, because the question is what your medical records show, not how long you happened to be on the medication.

The qualifying diagnoses reach beyond the strict label “CTCL.” Fourteen T-cell lymphoma subtypes meet the diagnosis criterion:

• T-Cell Lymphoma
• Cutaneous Lymphoma
• Anaplastic Large Cell Lymphoma
• Null Cell Types
• Mycosis Fungoides
• Sézary Syndrome
• Cutaneous Gamma/Delta T-Cell Lymphoma
• Epidermotropic Cytotoxic T-Cell Lymphoma
• Peripheral T-Cell Lymphoma
• Angioimmunoblastic T-Cell Lymphoma
• Adult T-Cell Lymphoma/Leukemia
• Composite Lymphoma
• Lymphomatoid Papulosis
• Natural Killer (NK)–Cell Lymphoblastic Lymphoma

If you were told you have a T-cell or skin lymphoma but are not sure of the exact subtype, that does not disqualify you. Subtype confusion is normal — it is resolved from your pathology records, not from memory. Claims may also be brought on behalf of a person who has died, through their estate. The one hard disqualifier: if another law firm already represents you for this claim, we cannot review it. For a plain-language walkthrough, see do I qualify for the Dupixent lawsuit.

Is the Dupixent Lawsuit a Class Action? (MDL 3180 Explained)

Most people search for a “Dupixent class action,” but that is not what this is. The Dupixent CTCL cases are individual lawsuits that the Judicial Panel on Multidistrict Litigation consolidated in June 2026 into a multidistrict litigation — MDL 3180 — in the U.S. District Court for the District of New Jersey, before Judge Zahid N. Quraishi. In an MDL, one court manages pretrial proceedings for every federal case, but each case remains its own lawsuit: your claim would rise or fall on your records, not on a single shared class outcome. At least 36 cases are on file as of September 15, 2026.

Here is the litigation’s status, stated the way we would want it stated to us:

Lawsuits consolidated in MDL 3180 (D.N.J.) allege that Dupixent (dupilumab) is associated with an increased risk of cutaneous T-cell lymphoma (CTCL) and that the manufacturers failed to warn about it. No court has ruled on these allegations, no settlement exists, and the litigation is in its earliest stages. Published studies report a statistical association — which the study authors themselves note does not establish causation — and the FDA has identified a potential safety signal it is still evaluating; Dupixent’s FDA label does not currently warn about lymphoma. Whether any individual has a claim depends on their medical records and the law of their state.

What the Studies Say About Dupixent and T-Cell Lymphoma (CTCL)

Start with how rare this cancer is: cutaneous T-cell lymphoma occurs at roughly 8.55 cases per million people per year in the United States, according to a SEER registry analysis published in JAMA Oncology. Against that baseline, several research groups have reported that CTCL shows up more often than its background rate would suggest among people who used dupilumab.

A 2024 retrospective cohort study in the Journal of the American Academy of Dermatology (Hasan et al.) reported about 4.1 times the odds of a CTCL diagnosis among atopic dermatitis patients who used dupilumab (odds ratio 4.10, 95% confidence interval 2.06–8.19) — and its authors wrote, in their own limitations, that the association “does not prove causality.” A second 2024 database cohort (Mandel et al., Dermatologic Therapy) reported a relative risk of 4.59. A 2025 pharmacovigilance analysis of FAERS data found CTCL reported disproportionately often for dupilumab (reporting odds ratios of roughly 8.8 to 10.4) — a measure of reporting patterns, not of disease risk. And a 2025 cohort of asthma patients (European Respiratory Journal) reported a hazard ratio of 4.58 for T- and NK-cell lymphomas — notable because asthma patients have no rash that could hide an existing skin lymphoma. Every one of these research teams says the same thing: this is association, not proven causation.

The raw federal reporting data sits behind those analyses. As of FDA data updated July 30, 2026, FAERS holds 479,014 adverse event reports mentioning Dupixent or dupilumab, of which 314 code the reaction “cutaneous T-cell lymphoma” — and no lymphoma term appears among the 25 most-reported reactions.

FDA adverse event reports reflect what was reported to the agency; they are not verified, and a report is not proof that a drug caused an event.

The regulator’s position matters too. In its October–December 2024 quarterly review, the FDA listed cutaneous T-cell lymphoma as a potential safety signal for Dupixent and stated it is evaluating the need for regulatory action. It has not required a warning, and the current Dupixent label contains no lymphoma or malignancy warning at all.

One more thing, because you have probably already seen it argued: the most common counter-argument — made loudly in patient communities — is that Dupixent did not cause anyone’s cancer; it revealed a cancer that was already there. That is a serious argument, and the studies above cannot yet separate causing from revealing. The lawsuits, for their part, allege that Dupixent caused or accelerated CTCL and that patients and doctors should have been warned about the risk being studied. No court has ruled on any of it.

Why Was It “Just Eczema” for So Long?

Early cutaneous T-cell lymphoma looks like eczema. Not vaguely like it — clinically and under the microscope, dermatology literature describes considerable overlap between atopic dermatitis and early-stage mycosis fungoides, and reaching the correct diagnosis routinely takes years and more than one biopsy, with early biopsies often coming back inconclusive. Many people in this litigation lived some version of that: a patch or lesion that never behaved like the rest of their eczema, treated as eczema anyway, sometimes for a very long time, until a biopsy finally said something different.

If that is your story, two things are worth saying plainly. First: you did not miss something obvious, and in most cases neither did your dermatologist — this disease is notorious for hiding inside an eczema diagnosis, and being misdiagnosed as eczema for years is the norm in CTCL, not a failure. Second: two things can be true at once. Dupixent may genuinely have given you your skin back — many patients describe it as life-changing — and you may still have a claim, because the claim is not about whether the drug helped you. It is about what the lawsuits allege the manufacturers knew about a developing risk, and what they never warned anyone about. You do not have to renounce a drug that helped you in order to ask that question.

How Does a Dupixent Claim Actually Work?

Marin & Murphy Law Firm is currently accepting Dupixent CTCL cases. The process starts with a free, confidential evaluation — a short conversation about your Dupixent use, your diagnosis, and your treatment. If the criteria fit, the next step is records: pathology and biopsy reports, pharmacy and prescriber records, and treatment history. Whether a claim is accepted is determined after that review, and no attorney-client relationship is created until a written engagement agreement is signed.

An accepted case is then filed in, or transferred into, MDL 3180, where it proceeds through the consolidated pretrial process alongside the other cases — while remaining an individual lawsuit valued on its own facts. We will not promise you an outcome, because no honest lawyer can: no court has ruled on the science, and no settlement exists. What we can promise is that the evaluation costs nothing, and that you will get a straight answer about whether your records support a claim.

Do You Have to Stop Taking Dupixent to File?

No. This comes up in almost every conversation, so it gets its own answer: filing a claim does not require you to stop, pause, or change your medication in any way, and contacting a law firm is not a medical decision. Whether to continue Dupixent is a question for you and your prescriber — not for us, and not for the internet. Nothing about the legal process asks you to choose between your skin and your claim.

Talking to a Dupixent Lawyer: What to Expect

If you or a family member were diagnosed with cutaneous T-cell lymphoma or a related T-cell lymphoma after taking Dupixent, the first conversation with a Dupixent lawyer is short and practical. You will be asked when you started and stopped the drug, when the diagnosis was made and by whom, and whether you still have prescription and pathology records — nothing needs to be gathered before you call.

A Dupixent lawsuit attorney reviews whether the timeline and diagnosis fit the criteria in MDL 3180, explains what filing an individual claim in the consolidated proceeding involves, and tells you plainly if the case does not qualify. There is no charge for that review, and no fee unless there is a recovery. Nothing about the conversation changes your medical care: decisions about continuing or stopping Dupixent stay with you and your doctor.

Dupixent Lawsuit FAQs