Study Highlights Link Between Tepezza and Hearing Problems After Four Injections of the Thyroid Eye Disease Drug

Amid rising concerns about the link between side effects of Tepezza and hearing loss, the findings of a recent study suggests that nearly a third of patients who experience hearing problems after receiving the thyroid eye disease injection do not improve, leaving them with permanent ear damage.

Tepezza (teprotumumab-trbw) is a biologic treatment approved by the FDA in January 2020, as the first drug approved to treat thyroid eye disease, which is caused by hyperthyroidism and linked to Graves’ disease, causing inflammation of eye muscles, eyelids, tear glands and fatty tissues behind the eye. Commonly referred to as bulging eye disease, this condition can cause blurred or double vision.

The FDA approved Tepezza through a fast-track Orphan Drug designation, which allowed the drug maker to introduce the injection without extensive testing, since it targeted a condition which has no other treatment available. However, a number of studies and case reports published over the last two years have identified a link between Tepezza and hearing problems, which critics indicate the manufacturer knew or should have known about.

Horizon Pharmaceuticals now faces Tepezza lawsuits brought by former users, who indicate that signs of the problems were apparent during clinical trials and should have been disclosed to users and the medical community.

While the Tepezza warning label briefly mentions hearing loss as a possible side effect, lawsuits allege that the drug maker downplays the problems as temporary, and that many users could have avoided permanent hearing loss of instructions had been provided about the importance of monitoring hearing on Tepezza.

In a study published earlier this year in the American Journal of Ophthalmology, Stanford researchers looked at 27 patients who had received at least four Tepezza injections and followed up with them up to 40 weeks later, finding that more than 80% of patients receiving Tepezza suffered some form of hearing problems.

A review of that study, published in August 2022, found that about one-third of all patients who experienced Tepezza hearing loss still suffered problems months after receiving the injections.

Dr. Richard C. Allen, of Baylor College of Medicine and the Cullen Eye Institute, indicates 22 out of the 27 patients suffered new or worsening hearing problems during the study, including hearing loss and tinnitus. Of those, only 68% of patients had resolution to their symptoms by the last follow-up visit, which occurred an average of 39.2 weeks after their last infusion.

Five out of the six patients who did not recover hearing met the criteria for Tepezza ototoxicity (toxicity of the ears), with two requiring the use of hearing aids.

The review indicates the link between hearing loss and Tepezza may be the result of the drug inhibiting insulin-like growth factor 1 (IGF-1), which plays a significant role in the functioning of the ear by protecting the inner ear hair cells from noise-induced hearing damage, ischemia and medication toxicity.

“This study supports findings from earlier case reports of the concern for potentially irreversible otologic issues in patients treated with teprotumumab,” Allen concluded. “This risk should be explicitly discussed with patients prior to treatment with teprotumumab, especially in those patients with baseline hearing loss.”

As more individuals discover that there may be a link between their prior injections of Tepezza and hearing loss experienced over the past two years, it is expected that the number of lawsuits filed throughout the U.S. court system will increase, and several hundred individuals may soon be pursuing Tepezza hearing loss settlements from the manufacturer.