The next major stage in Dupixent Products-Liability MDL 3180 is phased discovery starting with general causation. That means the court first asks whether Dupixent can cause or worsen cutaneous T-cell lymphoma (CTCL) before moving individual cases toward trials. MDL means multidistrict litigation, a setup that sends related federal lawsuits to one judge for shared pretrial work. The U.S.
Judicial Panel on Multidistrict Litigation created the MDL on June 4, 2026. It moved 15 cases from 12 districts to New Jersey federal court before Judge Zahid N. Quraishi, as stated in its transfer order. Saiontz & Kirk reports that a Nov. 2, 2026 discovery order lifts the stay and puts expert work first in its discovery update.
Table of Contents
- What does general causation test?
- What happens in what order?
- Who is included as the docket grows?
- What does this stage not decide?
- Why watch New Jersey state court too?
What does general causation test?
General causation asks a broad science question: can Dupixent cause or speed up CTCL in patients at all? The court hears science first because a no answer stops many claims, while a yes answer lets individual cases proceed. Specific causation comes later and asks a personal question: did the drug cause this one person's lymphoma? Bellwether picks, which are test trials from representative cases, also wait until after the science ruling. That order keeps early work shared instead of repeating science fights in every case.
What happens in what order?
The proposed schedule builds the record in layers, starting with company files. Defendants were to produce the complete Dupixent regulatory file by Nov. 16, 2026.
The Joint Case Management Report filed Sept. 10, 2026 sets that order, as shown in the joint case-management report. CallFob reports Oct. 30, 2026 proposed orders addressed direct filing and depositions.
- plaintiffs' general-causation expert reports due Nov. 8, 2027
- defense expert reports follow plaintiffs' reports
- Daubert challenges test which experts can testify
- causation ruling comes before bellwether selection
Who is included as the docket grows?
The MDL began with 15 transferred cases. LegalScoops reports the count reached 38 pending cases in the Panel's Oct. 1, 2026 report.
CallFob reports about 40 cases by the Nov. 2, 2026 report. The centralized cases allege CTCL linked to Dupixent. LegalScoops notes the Panel left other T-cell lymphoma types for future transfer orders because every case before it alleged CTCL.
What does this stage not decide?
Centralization does not decide fault, injury value, or settlement. Nulegal explains in its MDL explainer that no court has found Dupixent causes CTCL.
The MDL also remains coordinated individual lawsuits, not a class action. Nulegal notes there have been no bellwether trials, Daubert rulings, or settlements. A reader should treat centralization as an efficiency step, not a forecast of payment.
Why watch New Jersey state court too?
LegalScoops reports Sanofi's mid-2026 filing reported about 30 federal plus eight New Jersey state-court Dupixent cases. That split matters because federal cases sit in the MDL while state cases follow state rules.
Plaintiffs sought New Jersey multicounty litigation in Middlesex County in September 2026. LegalScoops reports that request was still undecided at the time of its Oct. 24, 2026 coverage.