Dupixent CTCL lawsuits: the records that matter now that MDL 3180 is moving

The Dupixent CTCL cases are now in one federal court. On June 4, 2026,
the U.S. Judicial Panel on Multidistrict Litigation sent the federal
cases to the District of New Jersey and assigned them to Judge Zahid N.
Quraishi. The case is MDL No. 3180, In re: Dupixent (Dupilumab) Products
Liability Litigation.

That order does not decide whether Dupixent caused anyone's cancer. It
does not mean there is a settlement. It also does not mean every person
who ever used the drug has a case. What it does mean is that one judge
will manage the shared pretrial work: the science, the warnings, company
knowledge, and common discovery from Sanofi, Regeneron, and related
defendants.

For a family dealing with a CTCL diagnosis, the legal language can feel
far away. The useful step is much more ordinary. Save the records before
they get lost.

What changed in June

The JPML transfer order says the federal complaints raise overlapping
factual questions. Most plaintiffs used Dupixent, commonly for atopic
dermatitis, and were later diagnosed with cutaneous T-cell lymphoma.
Some claims were brought by spouses or survivors of Dupixent users.

The Panel described the main shared questions this way: whether the
scientific literature shows a causal link between Dupixent and CTCL,
when the companies should have learned about any such link, and whether
the warnings were adequate.

The order moved 15 actions and noted seven possible tag-along actions
across 12 districts. It also left one issue for later. The Panel did not
decide whether other T-cell lymphoma cases, beyond CTCL and its
subtypes, belong in the MDL. That can be handled through the conditional
transfer process if those cases appear.

The docket has already grown. The JPML's August 3, 2026 pending-MDL
report listed 28 actions in MDL 3180. That is not a large MDL yet, but
it is no longer just the opening group of transferred cases.

Why these cases turn on the medical timeline

CTCL is a cancer involving T cells that often shows up in the skin. The
problem, medically and legally, is that early CTCL can look like eczema,
psoriasis, or stubborn dermatitis. A patient may spend months or years
being treated for a skin condition before the word lymphoma enters the
chart.

That is why the timeline matters so much.

Some lawsuits allege Dupixent caused CTCL. Some allege it accelerated
CTCL that was already there. Others focus on delayed diagnosis or
unmasking, meaning the lymphoma may have looked like eczema until it
became clearer during or after treatment. Those are different theories.
The records have to do the work.

A useful timeline answers plain questions. When did the rash start? Was
it adult-onset? What treatments failed before Dupixent? When did
injections begin? Did symptoms improve, then change or worsen? When were
lymph nodes, plaques, tumors, severe itching, or systemic symptoms first
documented? When was a biopsy done? When was CTCL confirmed?

What the research says so far

The science is not settled, and families should be wary of anyone who
talks as if it is. Still, the research is one reason these cases moved
into an MDL.

A 2024 Journal of the American Academy of Dermatology retrospective
cohort study compared atopic dermatitis patients who used dupilumab with
patients who did not. The authors reported an increased CTCL risk in the
dupilumab group, with an odds ratio of 4.1003 and a 95% confidence
interval of 2.055 to 8.192. The same abstract notes real limits,
including possible database misclassification and the inability to
measure atopic dermatitis severity.

A 2024 Dermatologic Therapy study using TriNetX data also reported
increased CTCL risk among atopic dermatitis patients treated with
dupilumab. That study reported a relative risk of 4.59 after matching,
and said 34 of 55 CTCL cases in the dupilumab group were diagnosed
within the first year.

A 2025 European Respiratory Journal asthma study looked at lymphoma risk
in dupilumab-treated asthma patients. After propensity matching, the
authors reported a hazard ratio of 1.79 for lymphoma overall and 4.58
for T-cell and natural killer-cell lymphomas. The abstract also reported
lower all-cause mortality in the dupilumab group. That mixed picture is
exactly why the court process will matter.

None of these studies proves an individual case. Defendants are expected
to dispute causation and point out that CTCL can be mistaken for eczema
before Dupixent is prescribed. Plaintiffs will argue that the growing
medical literature and adverse-event history should have led to better
warnings and clearer screening guidance.

Records to gather before calling a lawyer

We would start with the prescription history. Get the start date, dose,
injection schedule, prescribing doctor, stop date, and pharmacy records
if available. If there were gaps or pauses in treatment, write those
down too.

Next, pull the dermatology records from before Dupixent. These notes may
show why the drug was chosen, whether the skin condition started in
adulthood, whether it looked unusual, and whether ordinary treatments
failed.

Biopsy and pathology reports are central. A CTCL, mycosis fungoides,
Sezary syndrome, or other T-cell lymphoma diagnosis needs to be anchored
in the pathology. Earlier biopsies can matter as well, especially if
they were negative, inconclusive, suspicious, or later re-read.

Oncology records help show the course of the disease. Chemotherapy,
radiation, photopheresis, systemic therapy, hospitalizations, transplant
evaluation, and follow-up notes all help a reviewer understand severity.

Photos can help if they already exist. Dated images of skin changes may
fill in the space between doctor visits. Do not stage or edit anything.
Keep the originals.

Then write the timeline in normal language. One page is fine. Dates,
doctors, symptoms, treatment changes, biopsy dates, and the diagnosis
date are more useful than a polished narrative.

Who may need a review

The current MDL is centered on CTCL and CTCL subtypes, including mycosis
fungoides and Sezary syndrome. The JPML left the door open for later
arguments about other T-cell lymphoma cases, but it did not decide that
issue in the transfer order.

A review may make sense when Dupixent use came before a CTCL diagnosis,
especially where the records show adult-onset dermatitis, unusual or
treatment-resistant symptoms, worsening during treatment, lymph node
involvement, delayed diagnosis, serious cancer treatment, or death after
a T-cell lymphoma diagnosis.

A rash by itself is different. Eye irritation, a routine eczema flare,
or a short-term side effect without a T-cell lymphoma diagnosis is not
the injury at the center of MDL 3180.

Talk to your doctor, and save your legal options

Do not stop Dupixent or change any prescription because of a lawsuit
article. Talk to the doctor treating you. Medical decisions should be
made with the people who know your condition.

The legal piece is separate. If Dupixent use came before a CTCL
diagnosis, we can look at the records and help determine whether the
claim should be investigated further. Filing deadlines vary by state, so
waiting too long can create problems even when the medical facts deserve
review.

A case review is not a promise that a lawsuit will be filed, that the
science will be accepted by the court, or that money will be recovered.

This article is attorney advertising and is for informational purposes
only. It is not medical advice and does not create an attorney-client
relationship. Past results do not guarantee future outcomes.

Sources

• JPML Transfer Order, MDL No. 3180, In re: Dupixent (Dupilumab) Products Liability Litigation: https://www.jpml.uscourts.gov/sites/jpml/files/MDL-3180-Transfer_Order-5-26.pdf
• JPML Pending MDL reports page, August 3, 2026 reports: https://www.jpml.uscourts.gov/pending-mdls-0
• Hasan et al., Journal of the American Academy of Dermatology, PubMed abstract: https://pubmed.ncbi.nlm.nih.gov/38588818/
• Mandel et al., Dermatologic Therapy / Jefferson Digital Commons abstract: https://jdc.jefferson.edu/dcbfp/198/
• Ma et al., European Respiratory Journal, PubMed abstract: https://pubmed.ncbi.nlm.nih.gov/40537179/
• Current Dupixent patient/prescribing information portal: https://www.dupixent.com/