Tepezza Tinnitus and Hearing Loss Lawsuits Move Into Expert Discovery Phase

With the first Tepezza bellwether trial over tinnitus and hearing loss side effects scheduled to begin in April 2026, plaintiffs have identified case-specific experts for the next phase of discovery.

As lawyers continue to prepare a small group of Tepezza tinnitus and hearing loss lawsuits for early trial dates, plaintiffs submitted general case-specific expert reports this week, for the next phase of pretrial discovery, which will continue for the next several months.

There are currently more than 200 product liability lawsuits being pursued against the makers of the thyroid eye disease drug, each raising similar allegations that earlier Tepezza hearing damage warnings should have been provided to users and the medical community.

Tepezza (teprotumumab-trbw) is a new-generation biologic treatment that was introduced by Horizon Therapeutics in January 2020, as the first medication approved to treat thyroid eye disease or bulging eyes, which is caused by hyperthyroidism and linked to Graves’ disease, resulting in inflammation of eye muscles, eyelids, tear glands and fatty tissues behind the eye.

However, amid a growing number of reports involving users experiencing hearing loss and tinnitus from Tepezza, the U.S. Food and Drug Administration (FDA) ordered the drug maker to update the prescribing guide in July 2023, adding information about the risk of irreversible hearing damage. Hundreds of former users now maintain that they could have avoided injuries if warnings had been included when the drug was first introduced.

Due to common questions of fact and law throughout the Tepezza tinnitus and hearing loss lawsuits brought throughout the federal court system, all claims have been consolidated into a multidistrict litigation (MDL) in the Northern District of Illinois, where U.S. District Judge Thomas Durkin is presiding over coordinated discovery and pretrial proceedings.

Tepezza Tinnitus and Hearing Loss Lawsuit Trials

As part of the litigation’s management, 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, to help the parties gauge how juries may respond to certain evidence and testimony that will be rpeated throughout the claims. 

Judge Durkin has 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.

According to a pretrial schedule issued earlier this year, fact discovery in the bellwether lawsuits was closed on May 9, 2025, and plaintiffs were required to submit general and case-specific expert reports by Monday, June 9. 

The parties will now move forward with expert discovery in the bellwether claims, with full-day depositions to be held between June 23 and July 18, 2025.  Horizon will then be required to submit their own expert reports in the four trial claims by July 18, with depositions of those experts held by August 8, 2025.

Following the conclusion of expert discovery, Judge Durkin has set a deadline of December 5, 2025, for the submission of summary judgment motions. A final pretrial case management conference for the first bellwether trial will be held in early March 2026.

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.

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

However, the parties have been directed to participate in Tepezza settlement talks at least once every quarter to seek a potential resolution that does not require hundreds of expensive and lengthy federal trials.