Dupixent (dupilumab) is a monoclonal antibody that blocks two immune signaling proteins, interleukin-4 and interleukin-13, which drive the inflammation behind atopic dermatitis, asthma, and several other conditions. Sanofi and Regeneron co-market it; it generates well over ten billion dollars a year. The lawsuits concern one rare outcome: cutaneous T-cell lymphoma.
Timeline
2020–2025. Case reports and then cohort studies describe CTCL appearing or progressing in Dupixent patients. Analyses of FDA adverse event data and insurance databases report risk several times higher than in untreated patients, increasing with duration.
2025–early 2026. Individual lawsuits filed in a dozen federal districts. The FDA begins evaluating whether regulatory action is warranted.
June 4–5, 2026. The JPML creates MDL 3180, In re: Dupixent (Dupilumab) Products Liability Litigation, in the District of New Jersey before Judge Zahid Quraishi, transferring 15 cases with more tagged to follow.
The panel limited the MDL to CTCL claims for now but left the door open to other T-cell lymphomas through the conditional transfer process. That scope question will shape who can join.
Direct2Attorney · Litigation ExplainerThe allegations
What plaintiffs claim
Common to the complaints- Manufacturers knew or should have known of the CTCL signal
- The label failed to warn or recommend screening
- The drug masked CTCL symptoms, delaying diagnosis
- Marketing overstated safety for long-term use
What the defense will argue
Anticipated- CTCL mimics eczema; misdiagnosis preceded the drug
- Association is not causation
- Absolute risk remains very small
- Federal labeling rules preempt state claims
The science, briefly
CTCL is a cancer of skin-homing T cells. IL-4 and IL-13 signaling is involved in the immune environment those cells live in. Two hypotheses are in play: that blocking these pathways lets malignant T cells expand unchecked, and that suppressing inflammation hides lesions that would have prompted biopsy. Both have laboratory and observational support; neither has been tested at trial. Expert challenges under Daubert will be the first major battle.
What comes next
Case management orders, plaintiff fact sheets, and a master complaint over the coming months. Discovery into the manufacturers’ pharmacovigilance data. If the FDA acts on its evaluation, that will be a significant development either way. Bellwether trials, if the case reaches them, are likely two or more years out.
What this means if you're considering a claim
New MDLs are the stage where cases are easiest to file and where early claimants help define the bellwether pool. If you used Dupixent and have a CTCL or related diagnosis, a free review can determine fit and connect you with a participating firm in MDL 3180.
Think your diagnosis fits?
Free, confidential review by a participating firm.
Common Questions
No. Each patient has an individual case coordinated in the MDL.
Yes, if they developed CTCL. The indication for which Dupixent was prescribed does not limit eligibility.
Currently outside the MDL’s defined scope, but the panel allowed for expansion. Firms are reviewing these cases.
As of September 2026, the FDA is evaluating. No label change has been announced.
No. Direct2Attorney’s review is free, and participating law firms typically work on contingency, meaning fees are generally paid only if there is a recovery. Confirm fee terms in writing with the firm.
