Tepezza, a medication manufactured by Horizon Therapeutics and used to treat thyroid eye disease, is the subject of mass tort litigation due to allegations that the company failed to adequately warn patients and healthcare providers about the risk of permanent hearing loss and tinnitus associated with the drug. Since the drug’s approval, numerous patients have reported serious auditory side effects, leading to lawsuits seeking compensatory and punitive damages.
Background of the Tepezza Lawsuit
Tepezza was approved by the FDA in 2020 as the first drug specifically for thyroid eye disease. Shortly after its release, reports began surfacing of hearing-related side effects occurring in up to 40% of patients during early clinical trials referred to as Study 401. However, the official drug label did not notify patients or doctors about these risks until July 2023, several years after the drug came to market.
This delay in updating warnings is a central issue in the lawsuits, which claim Horizon neglected to inform the public despite ample evidence. A whistleblower within the company allegedly raised concerns but was terminated.
Details of the Lawsuit Allegations and Claims
- Failure to warn patients and medical professionals about the risk of severe and potentially permanent hearing loss, tinnitus, and related conditions.
- Negligence in conducting adequate safety studies and post-marketing surveillance to detect and disclose auditory risks earlier.
- Deliberate delay in updating product labeling despite internal knowledge of hearing-related adverse events.
- Resulting harm to plaintiffs who claim lasting hearing damage attributable to Tepezza use.
- Claims for compensatory damages covering medical expenses, pain and suffering, and punitive damages to penalize misconduct.
Legal Framework and Relevant Laws
The lawsuits are consolidated into a multidistrict litigation (MDL) in the U.S. District Court for the Northern District of Illinois, citing negligence, product liability, failure to warn, and breach of warranty under state and federal law. Plaintiffs seek recognition of Horizon’s liability and financial compensation.
Health, Financial, and Social Impact
The litigation highlights serious health risks and raises questions about drug safety monitoring and labeling in the pharmaceutical industry. Patients are experiencing potentially irreversible auditory damages that affect quality of life and earning ability.
Financially, the lawsuits pose significant exposure for Horizon Therapeutics, recently acquired by Amgen, as settlements or judgments may reach hundreds of millions. Socially, the case raises awareness about the importance of drug safety transparency and regulatory vigilance.
Current Status and Developments
As of mid-2025, over 200 lawsuits are pending in the Tepezza MDL. The court has scheduled four bellwether trials between March and August 2026 to help assess case trends and encourage settlement discussions. Discovery is ongoing, and parties continue to prepare expert testimonies.
While an early settlement before trial is possible, the litigation remains active, with plaintiffs’ lawyers optimistic about successful outcomes.
Consumer Advice and Business Implications
Patients who have experienced hearing issues after Tepezza treatment should consult medical and legal professionals promptly. Retaining medical records and documenting symptoms is vital for pursuing claims.
Pharmaceutical firms face increasing pressure to prioritize thorough safety testing, timely public disclosures, and continued monitoring of adverse effects to mitigate risks and maintain trust.
Conclusion: The Significance and Outlook of the Tepezza Lawsuit
The Tepezza lawsuit underscores the critical need for transparency and accountability in drug safety management, especially for newer treatments. Its progression will impact pharmaceutical regulatory policies, patient rights, and corporate compliance standards, shaping the future approach to managing drug-related health risks.
