Tepezza Hearing Loss Lawsuit
(Permanent Hearing Damage)
Plaintiffs allege that Horizon Therapeutics (now Amgen) failed to adequately warn patients that Tepezza—the only FDA-approved treatment for thyroid eye disease—can cause permanent hearing loss and other serious auditory injuries at rates far higher than disclosed in clinical trials.
Key Takeaways
- 277 cases pending as of May 2026 — growing steadily since MDL creation
- Clinical trials reported 10% hearing issues, but independent studies found rates up to 71%
- July 2023: FDA added permanent hearing loss warning to product label
- Amgen (acquired Horizon for $27.8B) is the defendant
- Bellwether trial deadlines removed December 2025 — possible settlement talks
Key Facts (May 2026)
| Pending Actions | 277 cases in federal MDL |
| Total Actions Filed | 286+ cases historically |
| Key Defendant | Amgen Inc. (acquired Horizon Therapeutics Oct 2023) |
| Presiding Judge | Hon. Thomas M. Durkin (N.D. Illinois) |
| MDL Created | June 2, 2023 (transferred by JPML) |
| Alleged Injury | Permanent hearing loss, tinnitus, other auditory damage |
| FDA Warning Added | July 20, 2023 (SUPPL-23) |
| Can You Still File? | Yes, lawsuits are actively being filed |
FDA Hearing Loss Warning (July 20, 2023)
The FDA approved a critical label update for Tepezza, adding a new warning in Section 5.4:
"TEPEZZA may cause severe hearing impairment including hearing loss, which in some cases may be permanent. Assess patients' hearing before, during, and after treatment with TEPEZZA."
— FDA Prescribing Information, BLA 761143, Supplement 23
This warning was added 3.5 years after the drug's original approval in January 2020.
Case Growth
MDL-3079 has grown approximately 6-7x since its creation in June 2023, with cases continuing to be filed as more patients discover their hearing damage may be linked to Tepezza.
Source: JPML MDL Statistics Reports, June 2023-May 2026
1 What Is This Lawsuit About?
Tepezza (teprotumumab-trbw) is a monoclonal antibody approved by the FDA in January 2020 as the first and only treatment for thyroid eye disease (TED). The drug works by inhibiting insulin-like growth factor-1 receptor (IGF-1R) to reduce inflammation and tissue expansion in the eye orbit.
Plaintiffs allege that Horizon Therapeutics knew or should have known that Tepezza causes permanent hearing loss and other serious auditory injuries at rates far higher than disclosed. While clinical trials reported hearing issues in approximately 10% of patients, independent post-marketing studies using formal audiometric testing found rates as high as 65-71%.
2 What Is Thyroid Eye Disease?
Thyroid eye disease (TED), also known as Graves' ophthalmopathy, is an autoimmune condition affecting the muscles and tissues behind the eye. It most commonly occurs in people with hyperthyroidism due to Graves' disease—approximately one in three people with Graves' disease develop eye symptoms.
Common TED Symptoms
- Eye bulging (proptosis)
- Double vision (diplopia)
- Pain behind eyes or with movement
- Redness and inflammation
- Eyelid retraction
- Vision-threatening complications
Source: American Thyroid Association
Before Tepezza: Treatment options were limited to corticosteroids, orbital radiation, and surgery. Tepezza was revolutionary as the first drug to target the underlying disease mechanism—which made many patients willing to accept significant risks.
3 Scientific Evidence
The litigation hinges on a stark discrepancy between clinical trial data and independent post-marketing research:
Clinical Trial Data (FDA Label)
Hearing impairment reported in premarketing trials
Source: FDA-approved prescribing information, Table 1
NYU Prospective Study (Kay-Rivest et al. 2023)
"Hearing Loss Associated with Teprotumumab"
Otolaryngology–Head and Neck Surgery (PMID: 36939482)
FDA FAERS Analysis (Huynh et al. 2024)
Analysis of FDA Adverse Event Reporting System data
Otology & Neurotology (PMID: 39142306)
4 Regulatory & Legal Timeline
First and only FDA-approved treatment for thyroid eye disease. Breakthrough Therapy, Fast Track, Priority Review, and Orphan Drug designations.
Daniel Weibel files the first Tepezza hearing loss lawsuit.
Cases consolidated in the Northern District of Illinois before Judge Thomas M. Durkin.
SUPPL-23 adds warning that Tepezza "may cause severe hearing impairment including hearing loss, which in some cases may be permanent."
Amgen completes acquisition of Horizon Therapeutics, assuming liability for the Tepezza litigation.
Court denies Horizon's motion to dismiss based on federal preemption, allowing plaintiffs' state law claims to proceed.
All bellwether trial deadlines removed from the schedule, sparking speculation about potential settlement discussions.
5 About the Presiding Judge
Hon. Thomas M. Durkin
U.S. District Judge, Northern District of Illinois
Judge Durkin presides over MDL-3079 in Chicago. He has ordered quarterly settlement discussions between the parties, indicating the court's interest in potential global resolution. The recent removal of bellwether trial deadlines under his supervision has sparked speculation about ongoing settlement negotiations.
6 Who May Qualify for a Lawsuit?
Eligibility Requirements
- Received Tepezza infusions for thyroid eye disease
- Developed new auditory symptoms during or after treatment
- Symptoms include: hearing loss, tinnitus, ear fullness, autophony, or balance problems
- Have medical records or audiometric testing documenting hearing decline
7 Defendant in This Litigation
Amgen Inc.
Acquired Horizon Therapeutics (October 2023)
Amgen completed its acquisition of Horizon Therapeutics for $27.8 billion in October 2023, assuming responsibility for the Tepezza product line and all related litigation. As one of the world's largest biotechnology companies, Amgen has substantial resources to either defend the litigation or fund a comprehensive settlement.
Frequently Asked Questions
Is the hearing loss from Tepezza permanent?
In many cases, yes. The FDA label now explicitly warns that hearing loss "may be permanent." Research suggests that Tepezza damages cochlear hair cells, which do not regenerate in humans. While some patients may experience partial improvement after stopping treatment, many report persistent hearing loss.
Why are the hearing loss rates so different between studies?
Clinical trials relied primarily on patient self-reporting, which found 10% hearing impairment. Independent studies using formal audiometric testing found rates as high as 71%. Many patients don't notice gradual high-frequency hearing loss until it's measured objectively or becomes severe.
What is the current status of the litigation?
As of late 2025, bellwether trial deadlines have been removed, sparking speculation about potential settlement discussions. Judge Durkin has ordered quarterly settlement conferences. Expert discovery was completed in mid-2025, and the preemption defense was denied, allowing plaintiffs' claims to proceed.
Can I still take Tepezza for my thyroid eye disease?
Tepezza remains FDA-approved and is still the only approved treatment for TED. The decision should be made with your doctor after discussing the risks and benefits. The FDA now recommends hearing assessments before, during, and after treatment. For many TED patients, the vision-saving benefits may outweigh the hearing risks.
Does it cost anything to file a lawsuit?
Most Tepezza attorneys work on a contingency fee basis, meaning they only get paid if you win or settle your case. The fee is typically a percentage of the recovery. Initial consultations are usually free, allowing you to understand your options without any upfront cost.
Sources & References
8 official sources cited• FDA DailyMed - Tepezza Prescribing Information (Updated November 10, 2025)
• FDA Drugs@FDA - BLA 761143 Approval History
• Kay-Rivest E, et al. Otolaryngol Head Neck Surg. 2023 (PMID: 36939482)
• Huynh N, et al. Otol Neurotol. 2024 (PMID: 39142306)
• ClinicalTrials.gov - OPTIC Trial (NCT03298867)
• American Thyroid Association - Thyroid Eye Disease Patient Information
• JPML MDL Statistics Reports, June 2023-May 2026
• Northern District of Illinois, MDL-3079 Court Records
Attorney Advertising. The information on this page is provided for general informational purposes only and does not constitute legal advice. No attorney-client relationship is created by accessing or using this content.
Every case is unique, and results depend on the specific facts and circumstances involved. Past settlement amounts and case outcomes do not guarantee similar results in your case. If you believe you have a legal claim, you should consult with a licensed attorney in your jurisdiction who can evaluate your specific situation.