Is There a Tepezza Class Action Lawsuit?
No — and that distinction is worth understanding, because it works in your favor.
The Tepezza litigation is a multidistrict litigation (MDL No. 3079), not a class action. People use "class action" as shorthand for any big case against a drug company, and most of the sites you'll find searching for Tepezza information use the terms interchangeably. They are legally different things.
Class Action vs. MDL
In a class action, a small number of named plaintiffs represent everyone who fits the class definition. The case is litigated collectively and resolved collectively. If it settles, the fund is divided among class members — usually according to a formula that treats similarly-situated members alike. You may not have chosen your lawyer. Individual circumstances get limited weight.
In an MDL, every plaintiff files and keeps their own individual lawsuit. Cases from federal courts across the country are transferred to one judge for coordinated pretrial proceedings only — discovery, expert challenges, and dispositive motions that would otherwise be duplicated hundreds of times. You choose your own attorney. Your case is valued on your injuries, your audiograms, your age, your work, your medical history. If the litigation doesn't resolve globally, your case can be sent back to your home federal district for its own trial.
Why this matters for Tepezza specifically: hearing injuries in this litigation range from intermittent tinnitus to profound bilateral hearing loss requiring cochlear implants. Those are not remotely equivalent harms. The MDL structure lets that difference be reflected in what each claimant recovers. A class action would flatten it.
How MDL 3079 Came to Exist
The first Tepezza lawsuit, Weibel v. Horizon Pharmaceuticals, was filed in the Northern District of Illinois in August 2022. Others followed across multiple federal districts.
In January 2023, plaintiffs petitioned the U.S. Judicial Panel on Multidistrict Litigation to consolidate the cases. A second motion followed in March 2023, listing 18 pending cases across five federal districts and requesting the Northern District of California as venue.
Horizon opposed consolidation, arguing there were too few cases to justify an MDL and that future filings would be limited. The JPML heard oral argument on May 25, 2023 at the James A. Byrne U.S. Courthouse in Philadelphia.
On June 2, 2023, the Panel ruled against Horizon and ordered all federal Tepezza hearing loss cases centralized in the U.S. District Court for the Northern District of Illinois before U.S. District Judge Thomas M. Durkin, finding that consolidation would eliminate duplicative discovery and prevent inconsistent pretrial rulings.
Who Runs the Litigation
Judge Thomas M. Durkin — U.S. District Judge, Northern District of Illinois. Presides over the MDL, rules on dispositive motions, appointed plaintiffs' leadership, ordered the quarterly settlement conferences, and set the bellwether trial calendar.
Chief Magistrate Judge M. David Weisman — assigned in September 2023 to manage discovery with authority to modify deadlines and oversee settlement conferences. He issued the October 2025 order striking the bellwether deadlines.
Plaintiffs' leadership committee — attorneys appointed by Judge Durkin in June 2023 to conduct common-benefit work on behalf of all plaintiffs: taking Horizon corporate depositions, litigating document production, retaining common experts, and negotiating with the defense. Your own attorney represents you individually; leadership handles the shared litigation.
Defendants — Horizon Therapeutics USA, Inc. and its corporate successors. Amgen Inc. acquired Horizon for $27.8 billion in October 2023 and assumed the litigation.
What Has Actually Happened in the MDL
Preemption defeated (twice). Horizon argued that FDA approval of its label preempted state-law failure-to-warn claims. This argument generally fails for branded drugs, because federal regulations let a manufacturer strengthen a warning immediately when new risk evidence emerges — the "changes being effected" pathway at the heart of Wyeth v. Levine. In November 2023, Judge Durkin also rejected preemption as to pre-approval design defect claims, holding that federal law did not dictate Horizon's design choices before it sought approval, letting those state-law claims proceed. Horizon's July 2024 motion to dismiss twelve bellwether cases on preemption grounds likewise failed.
Discovery fought and completed. Core fact discovery ran roughly eighteen months and closed December 20, 2024, with case-specific bellwether discovery closing May 9, 2025. Along the way plaintiffs obtained Horizon's internal documents and deposed the company's regulatory affairs and pharmacovigilance personnel. In November 2024, the court found Horizon's counsel had made improper obstructive objections during the deposition of Horizon's Director of Regulatory Affairs.
Bellwether program built, then suspended. In November 2023 Judge Durkin ordered a twelve-case bellwether pool — four selected by each side, four drawn at random. Trial dates were set, moved, and reset several times through 2024 and 2025. On October 1, 2025, all bellwether deadlines were struck.
Settlement conferences ordered. In August 2024 the court ordered the parties into quarterly settlement negotiations, meeting at least once every 90 days. Those talks are ongoing.
What Bellwether Trials Are and Why They Matter
In an MDL with hundreds of similar cases, no court tries them all. Instead a small representative group — "bellwethers" — is prepared for early trial. The verdicts are not binding on anyone else, but they tell both sides how real juries respond to the actual evidence: the internal Horizon documents, the expert causation testimony, the plaintiffs themselves.
That information is what typically drives global settlement value. A defendant facing a string of plaintiff verdicts negotiates very differently than one that has won the first two.
In Tepezza, the parties never got there. The trial calendar was cleared while the claims remained fully intact — which is why the suspension is read as a settlement signal rather than a setback.
What Happens to Your Case Inside the MDL
Filing. Your lawsuit is filed individually. Depending on the procedure, it is either filed directly into the MDL or filed in your home district and transferred in.
Plaintiff fact sheet. You complete a detailed questionnaire covering your TED diagnosis, infusion dates and locations, hearing symptoms, treating providers, and hearing testing. Your attorney handles the drafting; you provide accurate information.
Records collection. Your attorney obtains infusion records, audiology records, and treatment history. You do not chase providers.
Common discovery. Leadership counsel conducts the shared work — corporate depositions, document review, general causation experts. Your individual case generally sits during this phase.
Resolution. If a global settlement is reached, your claim is submitted, scored under the settlement criteria, and negotiated within that framework. If no settlement occurs, individual cases can be remanded to your home federal district for trial.
What you're actually responsible for: accurate medical history, responsiveness to your attorney's requests, and preserving documentation. That's it.
Common Questions
Do I need to go to Illinois? Almost certainly not. MDL proceedings are conducted by counsel. Most claimants never appear in court. If your case were selected as a bellwether — statistically unlikely — that changes, and your attorney would walk you through it.
Can I still file if the MDL already exists? Yes. New cases are still being accepted and filed into MDL 3079.
Does joining the MDL mean I get whatever everyone else gets? No — that's the class action model. In an MDL your recovery reflects your own injuries and documentation.
How long does this take? The MDL was created in June 2023 and is now in active settlement negotiations. If a global resolution is reached, filed claims typically see distribution 6 to 18 months after announcement, after claims administration and lien resolution. If negotiations fail, timelines extend significantly.
What if I have a claim in state court instead? MDL 3079 covers federal cases. Some claims proceed in state court. Which forum is right depends on your circumstances — that's part of what a case review determines.
Talk to a Tepezza Lawyer
Baker Legal Team has been filing Tepezza claims since before this MDL existed. Free review, nationwide, no fee unless you recover.
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ATTORNEY ADVERTISING. Prior results do not guarantee a similar outcome. Informational only; not legal advice.