Tepezza Hearing Damage Emerged After 5 Months of IV Infusions for Thyroid Eye Disease: Lawsuit

According to allegations raised in a recently filed product liability lawsuit, side effects of Tepezza left a New Jersey man with permanent hearing loss and tinnitus, after he received a series of IV infusions of the thyroid eye disease drug, which now carries warnings about the risk of hearing damage.

The complaint (PDF) was brought by Daryl Pantano in the U.S. District Court for the Northern District of Illinois on November 22, indicating that the drug manufacturer, Horizon Therapeutics USA Inc., intentionally delayed the dissemination of critical information about the hearing risks associated with the treatment, by disputing warning label language proposed by the FDA.

Tepezza (teprotumumab-trbw) was introduced in January 2020, as the first treatment for bulging eyes and double vision that results from thyroid eye disease, which is caused by hyperthyroidism and linked to Graves’ disease. The underlying condition causes inflammation of eye muscles, eyelids, tear glands and fatty tissues behind the eye, and multiple Tepezza IV infusions are often prescribed by many doctors.

Although Tepezza was marketed as a safe and effective treatment, a growing number of former users, like Pantano, are now coming forward to file Tepezza lawsuits, indicating that they may have avoided permanent hearing damage if earlier warnings and information had been provided for users and the medical community.

Pantano indicates that he was prescribed a series of Tepezza IV infusions between November 2021 and April 2022, after being diagnosed with thyroid eye disease.

However, the lawsuit notes that during that time, Horizon Therapeutics did not provide any warnings to him or his doctor about the risk of permanent Tepezza hearing damage from the infusions, even though there was substantial evidence that the drug was causing problems among users.

The lawsuit alleges that Horizon not only withheld critical information and warnings about the risk for years, but further delayed adding label language even after the U.S. Food and Drug Administration determined that Tepezza hearing loss could be permanent.

“Despite Horizon’s knowledge of severe and permanent hearing loss caused by Tepezza, it disputed the language proposed by the FDA and continued to argue that permanent hearing loss was uncommon,” the lawsuit indicates. “Horizon’s dispute of the language of the warning further delayed the dissemination of this critical warning information to Plaintiff, Plaintiff’s healthcare providers, and the medical community.”

The delay resulted in the Tepezza hearing damage warnings not actually being added to the label until July 2023, the lawsuit notes.

Tepezza Hearing Damage Lawsuit Update

Pantano’s complaint will be consolidated with nearly 200 other Tepezza hearing damage lawsuits currently being pursued in the federal court system, which have been centralized as part of an MDL, or multidistrict litigation, in the U.S. District Court for the Northern District of Illniois.

Due to common questions of fact and law raised in complaints throughout the federal court system, the Tepezza  MDL has been assigned to U.S. District Judge Thomas M. Durkin, for coordinated discovery and pretrial proceedings.

To help the parties gauge how juries may respond to certain evidence and testimony that will be repeated throughout the claims, Judge Durkin has established a Tepezza “bellwether” program, where a group of 12 representative cases are going through case-specific discovery and preparations for a series of early trial dates, which are currently scheduled to begin in March 2026, May 2026, June 2026 and August 2026.

While the outcome of these early bellwether trials will not have any binding impact on other claims presented in the litigation, the average Tepezza hearing damage lawsuit payouts awarded by juries are likely to have a large impact on settlement negotiations between the parties.

Following the bellwether trials, if the parties fail to reach Tepezza settlements or another resolution for the litigation, Judge Durkin may begin remanding individual cases to U.S. District Courts nationwide for separate trial dates in the coming years.