The Judicial Panel on Multidistrict Litigation transferred In re: Tepezza Mktg., Sales Pracs., and Prods. Liab. Litig. to Judge Thomas M. Durkin in the Northern District of Illinois on June 2, 2023, the same multidistrict vehicle that consolidated the Philips CPAP litigation. By spring 2026 the docket had grown to roughly 277 pending actions. Plaintiffs allege Horizon Therapeutics failed to warn that teprotumumab-trbw infusions for thyroid eye disease caused permanent sensorineural hearing loss and tinnitus.
Amgen closed its acquisition of Horizon on October 6, 2023. Horizon's pre-acquisition labeling decisions remain central to the litigation, and Amgen is now the parent company.
Why were Tepezza lawsuits consolidated into MDL 3079?
Horizon opposed centralization. It argued the motion was premature and that informal cooperation among the parties was already underway. The JPML disagreed. It found that consolidation would curb duplicative discovery and prevent conflicting pretrial rulings.
The transfer motion involved 18 actions across five districts, along with 19 additional potentially related actions. The Panel assigned the matter to Judge Durkin under master docket 1:23-cv-03568 for three reasons:
- The first-filed action was pending in the Northern District of Illinois.
- More actions were pending there than in any other district.
- The Panel expressed confidence in Judge Durkin's capacity to manage the litigation.
Magistrate Judge M. David Weisman was assigned to oversee discovery and confidentiality matters. The docket then grew steadily, from 59 pending actions in late 2023 to approximately 277 by spring 2026.
The failure-to-warn record and the Liu hearing-loss allegations
The failure-to-warn theory turns on the gap between what Horizon knew about hearing-impairment rates and what the label disclosed. The original label, approved January 21, 2020, listed hearing impairment as an adverse reaction at roughly 10%, drawn from the approval trials (NCT01868997 and NCT03298867), but did not carry it as a Warning or Precaution.
Plaintiffs allege that former Horizon clinical-development scientist Dr. Wenzhong "Jerry" Liu raised internal concerns about hearing-impairment rates well above the 10% label figure. The complaints further allege that Horizon held internal data showing rates as high as 40% by early 2020, and that Liu was terminated after pressing for label disclosure.
Independent evidence was accumulated outside the pleadings. The FDA's early-2023 FAERS quarterly report flagged Tepezza hearing impairment as a formal safety signal for the first time. A 2023 analysis published in Endocrine Practice found that more than 16% of patients experienced hearing-related complications, materially above the original label figure.
In July 2023, the FDA approved a revised label with a warning that Tepezza may cause severe hearing impairment. The warning includes the risk of permanent hearing loss. The roughly 3.5-year gap between approval and that warning frames the core liability window under Wyeth v. Levine, 555 U.S. 555 (2009): under the changes-being-effected regulation, a branded manufacturer may strengthen a label when new safety evidence emerges, without first obtaining FDA approval. Because the changes-being-effected mechanism applies in substantively the same way to Tepezza as a biologic, the failure-to-warn analysis tracks ordinary branded-drug precedent.
How the preemption and Michigan rulings divided the docket
Two dismissal pathways produced opposite results, and together they define which theories survive across the docket.
The preemption question came to a head in the bellwether-discovery case of plaintiff Cynthia Williams. Horizon moved to dismiss her complaint. It argued that federal law preempted her state design defect claims. In a November 3, 2023 order, Judge Durkin granted dismissal of Williams's post-approval design defect claims but denied dismissal of her pre-approval design defect theory. The court reasoned that Horizon controlled the drug's design before it sought FDA approval and had identified no federal law that would have barred a safer pre-approval design. That reasoning departed from the Sixth Circuit's contrary approach in Yates v. Ortho-McNeil-Janssen Pharmaceuticals, Inc., 808 F.3d 281 (6th Cir. 2015), and preserved a pathway for plaintiffs' pre-approval design defect claims throughout the litigation.
A separate track emerged under Michigan law. In an October 2024 ruling, the court applied Illinois choice-of-law analysis to a bellwether plaintiff who resided, was treated, and was injured in Michigan, and held that Michigan's pre-repeal drug-immunity statute, MCL 600.2946, controlled.
Michigan's Senate Bill 410, signed December 7, 2023 and effective February 13, 2024, repealed that immunity. The court found the repeal was not retroactive, so Michigan plaintiffs whose injuries predate February 13, 2024 remain subject to the prior bar. That carve-out requires separate reserve analysis from the main docket pool.
Discovery closure and the bellwether trial schedule
Discovery has been the gating factor for the litigation's timeline. A November 2023 case management order set the framework for selecting bellwether candidates within roughly 60 days, and the parties spent 2024 building the discovery record around those cases. Core fact discovery has since closed, but the court granted extensions on expert-deposition deadlines during 2025, and those extensions cascaded into the motion and trial calendar.
The bellwether program followed a 4/4/4 selection model: plaintiffs chose four cases, Horizon chose four, and the court selected four at random. That process created a 12-case bellwether discovery pool. The schedule reset more than once as deadlines moved. After those resets, the first bellwether trial is set for August 3, 2026, followed by trials on September 28, 2026, November 30, 2026, and February 1, 2027, each expected to run three to four weeks. Because no bellwether has yet been tried, the docket carries no verdict data, so settlement modeling drives the analysis.
Where settlement stands after the discovery cutoff
No global settlement has been publicly announced. With fact discovery closed and bellwether dates set, court-encouraged settlement discussions create conditions for a docket-wide resolution before any bellwether verdict. Relative to other mass torts, MDL 3079 remains modest in size, a profile that tends to favor an aggregate resolution priced off comparator dockets.
The bellwether-by-mediation posture points toward negotiation against test-case risk before market-setting verdicts, a trajectory also seen in other pharmaceutical dockets such as the Ozempic MDL.
Comparable hearing-loss and failure-to-warn settlement benchmarks
Two dockets frame the reserve-pricing analysis for MDL 3079. These include:
3M Combat Arms (MDL 2885, N.D. Fla.)
3M Combat Arms (MDL 2885, N.D. Fla.) is the closest hearing-loss comparator. The 3M earplug settlement reached roughly $6.0 billion in August 2023. It was structured as $5.0 billion in cash and $1.0 billion in stock paid from 2023 through 2029 and resolved approximately 250,000 claims. Across sixteen bellwether trials, plaintiffs prevailed in ten, and the final trial, Beal v. 3M Co., returned $5 million in compensatory damages and $72.5 million in punitive damages, a 14.5-to-1 ratio.
Elmiron (MDL 2973, D.N.J.)
Elmiron (MDL 2973, D.N.J.) is the closer failure-to-warn template. Janssen's June 2020 label change adding a retinal warning drove tier valuations, and the docket has fallen from 1,988 total filings to 568 pending by May 2026, a 71% reduction consistent with confidential individual settlements. No global settlement has been announced, and no public bellwether verdicts have been reported, a pattern echoed in the Parkinson's paraquat litigation, where causation evidence and bellwether sequencing have similarly shaped settlement timing.
For pharmaceutical product-liability coverage, the Liu allegations and the bellwether-by-mediation structure that avoids market-setting verdicts remain central to reserve analysis. The Michigan carve-out for pre-February 2024 injuries requires separate coverage attention.
Practice considerations for counsel tracking the litigation
The procedural posture in 2026 creates distinct action items for counsel tracking the docket.
For plaintiff counsel
- Cases lacking pre-infusion baseline audiometric testing present weaker causation records; the audiologic file should bracket the infusion window on both sides.
- The Liu-related allegations, together with custodial documents from Horizon's pharmacovigilance and regulatory affairs files, anchor the causation theory, so docket entries identifying those productions remain important.
- Plaintiff-fact-sheet completeness remains an inventory priority, and multi-facility record retrieval often gates how quickly case sets reach the steering committee with complete medical records before tier modeling begins.
For defense counsel
- The Williams preemption ruling forecloses Wyeth-based defenses where changes-being-effected-eligible safety data existed before a label change, while preserving preemption of post-approval design theories.
- The Michigan dismissal is replicable only in jurisdictions with non-retroactive FDA-approval shields, so state-of-injury mapping remains central at intake.
For coverage counsel
- Fact-discovery closure and the bellwether schedule are procedural markers for reserve adjustment; reserves built on trial-verdict assumptions may require recalibration against comparable benchmarks.
- Reinsurance notice obligations may re-trigger as the court continues to press settlement discussions.
What MDL 3079 signals for failure-to-warn dockets
The litigation enters its trial year with fact discovery closed and a reset bellwether calendar. Settlement architecture will likely tie the July 2023 label change to dosing history and audiometric severity. For counsel modeling Tepezza's endgame, the bellwether-driven mediation that shaped the Bard PowerPort litigation offers the closest procedural parallel.
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