Tepezza Lawsuit Claims Thyroid Eye Disease Drug Caused Hearing Loss, Tinnitus

Case was filed as lawyers continue to prepare a different Tepezza hearing loss lawsuit for a bellwether trial next year, to help gauge how juries may respond to allegations repeated throughout dozens of claims.

A product liability lawsuit brought by a New York man alleges that an infusion he received for treatment of thyroid eye disease left him with severe hearing loss and tinnitus, indicating that the manufacturer failed to warn users and the medical community about the potential side effects of Tepezza.

In a complaint (PDF) filed in the U.S. District Court for the Northern District of Illinois on October 9, plaintiff Christopher Oakes argues that the Tepezza manufacturer, Horizon Therapeutics, knew or should have known that the intravenous (IV) infusion delivered for treatment of an eye condition may cause irreversible hearing damage.

Tepezza (teprotumumab-trbw) is the first drug ever approved for the treatment of thyroid eye disease, which is also commonly referred to as bulging eye disease, involving inflammation that causes the eyes to protrude from their sockets. However, after it was introduced in 2020, a growing number of individuals soon began reporting hearing loss and tinnitus from Tepezza, which was not mentioned as a potential risk on the warning label, leading many users to continue receiving the infusions.

In July 2023, the U.S. Food and Drug Administration (FDA) required Horizon to update the Tepezza warnings, adding new information about the risk of irreversible hearing damage, and providing doctors with crucial instructions to monitor patients’ hearing before and during treatment to detect any signs or symptoms of hearing loss early.

According to the lawsuit, Oakes indicates he received Tepezza infusions from September 2022 through February 2023. That short time was all it took for him to suffer permanent hearing loss and tinnitus, a persistent ringing in the ears that Oakes will likely have to endure for the rest of his life.

Oakes notes that the manufacturer never informed him or his doctor about Tepezza hearing loss side effects or that his hearing should be regularly checked while on the medication.

The complaint points to the fact that Tepezza was used on less than 100 patients in its clinical trials to win FDA approval, yet shortly after the drug hit the market, reports of problems began. However, the manufacturer still refused to add a warning label until forced by the FDA, the lawsuit claims.

“Numerous patient reports, including significant newly acquired reports immediately following Horizon’s launch of Tepezza, scientific studies, and even Defendant’s post-marketing studies established that Tepezza causes hearing loss. Nevertheless, Defendant failed to warn, instruct, advise, educate, or otherwise inform Tepezza users, Tepezza prescribers, or United States governmental regulators about the risk of hearing loss, or the need for medical and/or audiological monitoring.”

–Christopher Oakes v. Horizon Therapeutics USA Inc.

Oakes presents claims of failure to warn, design defect, negligent failure to warn, and negligent design. He seeks both punitive and compensatory damages.

Delay Expected for First Tepezza Trials

The complaint will be consolidated with more than 230 similar Tepezza hearing loss lawsuits pending in the federal court system as part of an MDL (multidistrict litigation), which is centralized before U.S. District Judge Thomas Durkin in the Northern District of Illinois for coordinated discovery and pretrial proceedings.

To help 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 four hearing damage and tinnitus lawsuits are being prepared for early trial dates. 

The judge originally scheduled the first bellwether trial to begin on April 6, 2026, followed by a second trial on June 1, a third starting on July 27 and the fourth set to start on September 21 of that year. However, last month plaintiffs requested a 60-day extension to prepare the claims for trial.

A text-only entry (PDF) added to the docket on August 6 indicated that the parties met with Magistrate Judge M. David Weisman to discuss the case’s status. He called for the parties to submit a joint proposal for an adjusted discovery schedule “which will likely affect trial dates.”

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

Leading up to the start of the first trial, lawyers have been directed to participate in Tepezza settlement negotiations at least once every three months, as part of an effort to seek a resolution that will not require the court to remand hundreds of individual cases back to U.S. District Courts nationwide for separate trial dates in the coming years.