Tepezza Lawsuit Updates
Litigation status: New cases being accepted. Below is a running record of every significant development in the Tepezza hearing loss litigation, MDL No. 3079, pending in the U.S. District Court for the Northern District of Illinois before Judge Thomas M. Durkin.
July 2026 — MDL Reaches 277 Cases as Settlement Talks Continue
The Tepezza MDL now includes 277 pending cases. The litigation remains in its post-bellwether-suspension posture: all trial deadlines struck, quarterly settlement conferences continuing under Judge Durkin's direction, no claims dismissed.
There has been no public announcement of a settlement, and none should be assumed. But the shape of the litigation right now — trial dates off the calendar, mandatory negotiations on the calendar, and a defendant with a $27.8 billion acquisition to protect — is the shape mass torts typically take shortly before a resolution framework emerges.
Baker Legal Team continues to evaluate and accept new Tepezza hearing loss cases. If you received Tepezza infusions and developed hearing loss or tinnitus, this is the time to have your claim reviewed — not after a settlement is announced.
May 2026 — Quiet Docket, Active Negotiations
The MDL docket has been largely static through the spring. In mass tort litigation this is not a sign that a case has gone cold; it is usually the opposite. When both sides are engaged in serious global settlement discussions, neither wants to generate rulings or incur trial-preparation expense that could complicate the negotiation. Filings continue at a modest pace and new cases are still being accepted.
March 2026 — Litigation Holds at Approximately 273 Cases
The docket has held near 273 pending claims. Notably, nothing adverse has happened to the plaintiffs' side of this case: no summary judgment has stripped out claims, no expert has been excluded in a way that guts causation, no dismissal order has been entered. The pause in the trial calendar reflects negotiation posture, not litigation weakness.
January 2026 — Status Conference Held; Docket at 273
Judge Durkin convened a status conference on January 8, 2026 to address case management and the path forward after the bellwether program was suspended. The MDL stood at 273 pending cases, essentially flat from December.
Under the pre-suspension schedule, this would have been the month the court ruled on Rule 702 challenges to expert testimony, with summary judgment briefing in the four bellwether cases due in February. Those deadlines came off the calendar in October.
November 2025 — All Bellwether Trial Deadlines Struck
This is the most consequential development in the litigation to date.
On October 1, 2025, Chief Magistrate Judge M. David Weisman held an off-the-record conference with counsel for both sides and then issued a docket entry striking every deadline associated with the bellwether trial program. The first Tepezza trial — which had been set for June 2026, with three more to follow — came off the calendar entirely.
The context matters. This followed roughly a year of settlement negotiations that Judge Durkin had ordered the parties to conduct, requiring them to meet at least once every 90 days. And critically, the deadlines were struck without any ruling dismissing claims, excluding experts, or granting judgment to the defense. Nothing happened to weaken the plaintiffs' cases. The trials simply stopped being prepared.
When a court clears a mass tort trial calendar under those circumstances, the near-universal interpretation among mass tort practitioners is that the parties are deep enough in settlement discussions that continued trial preparation would be wasted expense.
What this means if you have a potential claim: global settlement programs are generally built around claims that already exist. When a framework is announced, the eligibility criteria and registration deadlines are set — and people who haven't filed yet are frequently the ones who find themselves outside the window. If you have a Tepezza hearing injury and haven't spoken to a lawyer, do it now.
September 2025 — Docket at 272; Expert Discovery Extended
The MDL grew to 272 pending cases. The court granted a 45-day extension on expert deposition deadlines, which cascaded into the summary judgment and pretrial schedule. At this point the first bellwether trial was still nominally set for 2026 with subsequent trials staggered through the year — a schedule that would be vacated weeks later.
August 2025 — First Trial Pushed to August 2026; MDL Hits 260
The first bellwether trial was rescheduled to August 3, 2026, with subsequent trials set for September 28, 2026, November 30, 2026, and February 1, 2027 — each expected to run three to four weeks. The MDL reached 260 pending lawsuits.
Also this month: a new complaint filed by an Indiana woman laid out with unusual clarity the allegations at the core of this litigation. She received infusions from July 2021 through January 2022 — a period when Tepezza's label said nothing about permanent hearing loss or tinnitus and recommended no audiological monitoring whatsoever. Her complaint alleges Horizon's internal expanded-access program, Study 401, showed hearing-related adverse events in up to 40% of patients, with those results known as early as March 2020, and that the company chose a slower regulatory route instead of an immediate CBE label change. It further alleges the whistleblower who pressed the issue internally was terminated.
July 2025 — Extended Schedule Set; Docket at 236
The court issued a revised schedule pushing key deadlines into mid-to-late 2026: plaintiffs' expert depositions in late August and September, defense expert work through mid-October, Rule 702 briefing complete by January 9, 2026 with argument the week of January 19, rulings targeted for February 9, and summary judgment motions in the bellwether cases due February 6, 2026.
June 2025 — Expert Discovery Phase Opens; MDL at 221
With fact discovery closed, plaintiffs served expert reports and the litigation moved into expert discovery — the phase where causation is fought out. More than 200 lawsuits were pending, each alleging Horizon failed to warn that Tepezza could cause permanent hearing damage.
Also filed this month: a claim by a plaintiff who developed permanent tinnitus and hearing damage after only three infusions, a reminder that completing the full eight-infusion course is not required to have a viable claim.
May 2025 — Fact Discovery Closes; Horizon's Dismissal Bid Denied
Core fact discovery closed on May 9, 2025, ending roughly 18 months of document production and depositions of Horizon personnel — including its regulatory affairs and pharmacovigilance staff. Horizon's attempt to dismiss the litigation outright was denied. The MDL stood at 217 cases.
April 2025 — Deposition Cap Ruling
The court denied plaintiffs' motion to compel depositions of six Horizon Patient Access Liaisons and a sales representative beyond the 30-deposition limit set in Case Management Order No. 5, finding plaintiffs hadn't shown good cause under Rule 30 to exceed the agreed cap this late in discovery. A procedural setback that did not touch the core liability record.
March 2025 — Bellwether Trial Dates Set
Judge Durkin scheduled the first four Tepezza trials — the first for April 6, 2026, followed by June 1, July 27, and September 21, 2026 — and set an amended discovery schedule closing fact discovery May 9, 2025, with summary judgment motions due December 5, 2025 and a final pretrial conference in early March 2026. The cases were drawn from a pool of twelve representative claims.
February 2025 — Court Orders Second Deposition of Horizon Pharmacovigilance Official
After reviewing the transcript of a seven-hour deposition of a senior Horizon pharmacovigilance employee, the court found the witness's answers were often evasive and ordered him to sit for a second, three-hour session. Pharmacovigilance is the function inside a drug company responsible for tracking adverse event reports — precisely the department that would have seen hearing complaints accumulating after launch.
January 2025 — Bellwether Selections Submitted; Docket at 200
Following the close of core fact discovery in December, both sides submitted their proposed picks for the first four trial cases from the twelve-case discovery pool.
December 2024 — Core Fact Discovery Closes
Core fact discovery closed December 20, 2024. Over the preceding year, plaintiffs obtained Horizon's internal documents and deposition testimony central to the failure-to-warn theory: what the company knew about hearing risk, when it knew it, and why the label wasn't changed. The MDL reached 191 pending cases.
November 2024 — Court Finds Defense Deposition Conduct Improper
Plaintiffs moved for relief after Horizon's counsel repeatedly interrupted the deposition of Horizon's Director of Regulatory Affairs with speaking objections and foundation challenges to documents Horizon itself had produced. On November 1, Magistrate Judge Weisman found the conduct improper, noting that documents produced in discovery carry an implication of authenticity and that a running objection would have sufficed. No sanctions were imposed, but the ruling put the court's view of the parties' conduct on the record.
October 2024 — Michigan Statute Removes One Bellwether
Horizon successfully removed one of the twelve bellwether cases by invoking a since-repealed Michigan statute that barred product liability claims involving FDA-approved drugs. Judge Durkin ruled Michigan law applied because the plaintiff took the drug and was injured there, even though the suit was filed in Illinois. The repeal is not retroactive — which makes Michigan claims fact-specific and worth an individualized look. If you were treated in Michigan, call us; do not assume you have no claim.
August–September 2024 — Filing Volume Jumps; Settlement Conferences Ordered
August brought 33 new filings, the largest single-month increase to that point, bringing the MDL to 173. The parties also reached agreement on the number and phasing of depositions. Most significantly, Magistrate Judge Weisman ordered the parties to begin quarterly settlement conferences — the mediation structure that is still running today.
July 2024 — Trial Calendar Announced; Horizon Moves to Dismiss on Preemption
The court set the original bellwether trial dates. Horizon moved to dismiss twelve bellwether cases on federal preemption grounds, arguing the FDA had approved its label and it could not be held liable under state law for the warning's content. This argument generally fails in branded drug cases, because federal regulations expressly permit a manufacturer to strengthen a warning on its own initiative when new risk evidence emerges — which is exactly what plaintiffs allege Horizon declined to do.
June 2024 — Twelve-Case Bellwether Pool Selected
The court finalized the twelve-case bellwether discovery pool: four selected by plaintiffs, four by Horizon, four drawn at random by the court.
March 2024 — Plaintiffs' Bellwether Picks Filed
Plaintiffs submitted their four selections. Two involved plaintiffs diagnosed with permanent hearing loss; the other two involved permanent hearing loss combined with tinnitus.
December 2023 — Amgen Completes $27.8 Billion Horizon Acquisition
Amgen closed its acquisition of Horizon Therapeutics in October 2023 after resolving an FTC challenge, taking on the Tepezza litigation along with the asset. The MDL grew to 71 pending cases.
This was a meaningful development for claimants. Any eventual resolution is now backed by one of the largest biotechnology companies in the world — a defendant with both the resources to fund a settlement and a strong institutional interest in clearing an inherited liability off its books.
November 2023 — Preemption Defense Rejected on Design Defect Claims
Judge Durkin denied Horizon's motion to dismiss claims alleging the company should have developed a safer formulation of Tepezza before seeking FDA approval, holding that federal law does not preempt pre-approval design defect claims. The court also entered the case management order establishing the bellwether selection process.
September–October 2023 — Discovery Structure Put in Place
Magistrate Judge M. David Weisman was assigned to manage discovery, with authority to modify deadlines and oversee settlement conferences. The MDL grew to 54 cases.
July 2023 — FDA Requires Permanent Hearing Loss Warning
On July 17, 2023, the FDA approved an updated Tepezza label adding to the Warnings and Precautions section that the drug may cause severe hearing impairment, including hearing loss that may be permanent, and instructing physicians to assess patients' hearing before, during, and after treatment.
Three and a half years after approval. This label change is central evidence in the litigation — it establishes that the warning plaintiffs say they were owed was both possible and, eventually, necessary.
June 2023 — MDL 3079 Created
On June 2, 2023, the U.S. Judicial Panel on Multidistrict Litigation ordered all federal Tepezza hearing loss lawsuits consolidated before Judge Thomas M. Durkin in the Northern District of Illinois, over Horizon's opposition. The Panel found consolidation would eliminate duplicative discovery and prevent inconsistent pretrial rulings. Eighteen cases were pending when the motion was filed; roughly 35 by the time of the order.
May 2023 — JPML Hears Argument; Amgen Deal Wobbles
The JPML heard oral argument on consolidation on May 25, 2023 in Philadelphia. Horizon opposed, arguing there were too few cases to justify an MDL and that future filings would be limited. Meanwhile the FTC sought an injunction to block Amgen's acquisition of Horizon — a deal that would ultimately close later that year.
February 2023 — Horizon Raises Preemption
Horizon moved to dismiss the early cases on federal preemption grounds, arguing FDA regulation of its label displaced state tort claims.
August 2022 — First Tepezza Lawsuit Filed
Weibel v. Horizon Pharmaceuticals was filed in the Northern District of Illinois, alleging permanent hearing loss following infusions received from June through September 2020. The complaint alleged Horizon mischaracterized the hearing problems seen in its clinical trials as temporary or limited in duration, failed to study whether they were permanent, and failed to warn patients or regulators. It asserted failure to warn, design defect, negligent failure to warn, and negligent design, and sought compensatory and punitive damages.
May 2021 — The Study That Started It
Stanford researchers presented findings at the Endocrine Society's ENDO 2021 conference: among 26 patients who received at least four Tepezza infusions, 17 — 65% — developed hearing symptoms. Six reported hearing loss, seven developed tinnitus, three reported ear-plugging sensation, and roughly 29% developed autophony. Symptoms emerged after an average of about 3.6 infusions.
The label at the time said 10%, and described the effects as reversible.
Have a Tepezza Case?
Settlement negotiations are active and trial deadlines are suspended. New cases are still being accepted, but claims filed before a resolution framework is announced are the ones positioned to participate in it.
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