Dupixent CTCL Lawsuit: MDL 3180 Status and Who Qualifies

Dupixent (dupilumab) is an injectable biologic that blocks the interleukin-4 receptor alpha. It is approved for moderate-to-severe atopic dermatitis (eczema) in patients as young as 6 months, for certain asthma, for chronic rhinosinusitis with nasal polyps, and for other conditions. It is sold by Regeneron and Sanofi.

According to the JPML order that created the MDL, most plaintiffs used Dupixent, commonly prescribed for atopic dermatitis, and were later diagnosed with Cutaneous T-cell Lymphoma; they allege Dupixent caused their CTCL or accelerated a CTCL that already existed. Other plaintiffs are spouses or survivors of users. The common questions are whether the scientific literature shows a causal link, when the defendants should have learned of any link, and whether they gave adequate warnings.

T-cell lymphoma in the skin can look like eczema early on. That creates a central dispute: plaintiffs say the drug triggered or sped up the cancer, while the defense is expected to argue some patients had undiagnosed CTCL that was mistaken for eczema before they ever took Dupixent.

Regeneron, Sanofi, and Genzyme deny the claims. These are individual injury cases in a mass tort, and no court has found that Dupixent causes lymphoma.

Plaintiffs in cases from California, Florida, and Georgia asked the JPML to centralize the litigation. The defendants agreed a multidistrict litigation made sense but wanted it in New York or Florida. The panel chose the District of New Jersey, where Sanofi has its principal U.S. place of business and Regeneron has offices.

The panel also dealt with scope. The defendants wanted the MDL limited to CTCL. The movants agreed it should exclude B-cell lymphoma, Hodgkin lymphoma, and non-T-cell diseases, but wanted room for other T-cell lymphomas such as peripheral T-cell lymphoma. The panel declined to decide that question yet, noting that none of the plaintiffs before it alleged a T-cell lymphoma other than CTCL or one of its subtypes. Future non-CTCL cases can be addressed through the conditional transfer process.

Early MDL work usually covers leadership appointments, a master complaint, and fact sheets. Expect general causation and preemption fights before any trial.

The transfer order was signed by panel members Matthew F. Kennelly (acting chair), David C. Norton, M. Casey Rodgers, and Dale A. Kimball. It lists cases from districts including Alabama, and the panel said the fifteen actions and seven potential tag-alongs spanned twelve districts.

Attorneys reviewing these cases generally look for:

• Documented Dupixent use for any approved condition. Most filed cases involve eczema, but asthma patients are also being reviewed.
• A CTCL diagnosis confirmed by skin biopsy, such as mycosis fungoides or Sezary syndrome.
• Timing that fits: diagnosis after starting Dupixent, or clear worsening of a known CTCL after treatment.
• Family claims by spouses and survivors, which the MDL already includes.

You are less likely to fit the current MDL if your diagnosis is B-cell lymphoma, Hodgkin lymphoma, or another cancer. Other T-cell lymphomas are an open question. Also, if earlier biopsies already showed CTCL before you began Dupixent, the claim becomes harder, though acceleration is part of what plaintiffs allege.

Cutaneous T-cell lymphoma can take years to diagnose because early patches resemble eczema or psoriasis. If a dermatologist ever noted that your rash was not responding as expected, or ordered repeat biopsies, those notes can be important to the timeline.

The evidence is mixed, which is why the litigation will turn on expert testimony.

• Hasan et al., 2024, Journal of the American Academy of Dermatology. Using the TriNetX database, researchers compared eczema patients who used dupilumab with those who did not. They found an odds ratio of 4.1 for CTCL in dupilumab users, and 27 of 41 CTCL cases were diagnosed more than a year after starting the drug. The authors noted possible misclassification and that association does not prove causation.
• Ma et al., 2025, European Respiratory Journal. Among 14,936 asthma patients on dupilumab versus matched patients on inhaler therapy, dupilumab users had higher lymphoma risk (hazard ratio 1.79), especially T-cell and NK-cell lymphomas (hazard ratio 4.58), but lower all-cause mortality.
• Kridin et al., 2026, Frontiers in Medicine. A large database study found eczema itself raises lymphoma risk, and that dupilumab did not raise lymphoma risk compared with other systemic treatments and tended toward lower risk.

The U.S. Dupixent label, revised in April 2026, does not list lymphoma among its warnings. Plaintiffs say it should.

The competing studies measure different things. The 2025 asthma study compared dupilumab users with patients on inhaled steroid and long-acting bronchodilator combinations, matched by propensity score. The 2026 Frontiers study compared about 7,840 eczema patients on dupilumab with the same number on other systemic treatments, and it also found that eczema and other type 2 inflammatory diseases themselves were linked to higher lymphoma risk. That finding, that the underlying disease may raise lymphoma risk, is likely to be a central defense theme.

The MDL is only months old, so there are no verdicts, settlements, or reliable payout figures. If claims survive causation challenges, value in an individual case or any future settlement would depend on the CTCL stage and treatment (topical therapy versus chemotherapy, radiation, or stem cell transplant), prognosis, lost income, and the strength of the timeline.

Families of patients who died may bring wrongful death claims, and spouses may bring loss of consortium claims, both of which are already part of MDL 3180. Mass tort attorneys typically work on contingency. See class action vs. mass tort.

Because the MDL is new, early-stage decisions matter more than settlement talk right now. The first milestones to watch are the court's appointment of plaintiffs' leadership, any master complaint, and the schedule for expert discovery on general causation.

Until then, any figure quoted online for a Dupixent case is speculation. The more useful question is whether your records show a clear diagnosis and timeline.

Your deadline is set by your state's statute of limitations for personal injury or wrongful death, commonly two or three years, often starting when you knew or should have known your cancer might be linked to the drug. Defendants may argue that published studies starting in 2024, or publicity about the lawsuits that followed, started the clock.

A new MDL is not a reason to wait. Getting pathology and pharmacy records now also helps pin down when your diagnosis was made.

For a child who used Dupixent, many states pause the statute of limitations until the child turns 18, though some cap that extension. For a patient who died, a wrongful death claim usually runs from the date of death. Spouses' loss of consortium claims generally follow the injured person's deadline. These rules vary widely by state.

Dupixent's reach is one reason the litigation could grow. The U.S. prescribing information, revised in April 2026, lists these uses, among others:

• Atopic dermatitis (eczema), moderate to severe, in patients 6 months and older.
• Asthma, as add-on maintenance for certain moderate to severe asthma in patients 6 and older.
• Chronic rhinosinusitis with nasal polyps in patients 12 and older.
• Other indications updated on the label in 2025 and 2026, including bullous pemphigoid, chronic spontaneous urticaria, and allergic fungal rhinosinusitis.

Because Dupixent is approved for babies as young as 6 months with eczema, some potential claims involve children, and parents may be the ones bringing them. The filed cases so far mostly involve adults treated for eczema.

How the MDL was formed

Plaintiffs in three cases, Mun in the Southern District of California, Fraioli in the Southern District of Florida, and Nalls in the Northern District of Georgia, asked the JPML to centralize the cases in Georgia, or alternatively New Jersey or Illinois. Regeneron, Sanofi, and Genzyme agreed centralization was appropriate but proposed the Southern District of New York or a Florida district. The panel picked New Jersey and Judge Zahid N. Quraishi, describing him as an experienced transferee judge.

Signs a Dupixent case may be stronger or weaker

• Stronger: a biopsy-confirmed CTCL diagnosis made well after starting Dupixent, clear pharmacy records, and earlier skin biopsies that did not show lymphoma.
• Weaker: a diagnosis within weeks of starting the drug, a prior biopsy already suggesting lymphoma, or a lymphoma type outside the T-cell family.

These are general patterns, not rules. The 2024 JAAD study found 27 of 41 CTCL cases were diagnosed more than a year after dupilumab use, and the timing question will be central for experts on both sides.

1. Talk to your dermatologist or oncologist before stopping Dupixent; do not stop on your own.
2. Request your biopsy and pathology reports, including any older skin biopsies from before Dupixent.
3. Get specialty pharmacy records showing each Dupixent shipment.
4. Write down when your skin symptoms changed and when CTCL was first suspected.
5. Be wary of payout claims. No settlement exists.

In a case review, expect questions about why Dupixent was prescribed, when you started, how long you used it, when skin changes appeared, when CTCL was diagnosed, and whether any earlier biopsies were done. Because timing is the heart of these cases, a written timeline with dates from your records is the single most useful thing you can bring. You do not need every record to start; an attorney can request them with your permission.

Independent attorneys handling Dupixent cases can review your records and your state's deadline. A free case review takes about two minutes. Related: what an MDL is, the Ozempic lawsuit, and the breast implant BIA-ALCL lawsuit, which involves another T-cell lymphoma.