How Tepezza Went From Wonder Drug to the Focus of Hearing Loss Lawsuits

Thyroid Eye Disease (TED) is the progressive inflammation and damage to the tissue around the eyes. It can result in complete blindness. Although not classified as a rare disease in the U.S., NORD estimated that prevalence is between 90 and 300/100,000 people a year.

Also known as Graves’ Eye Disease, the options to treat it were limited. Doctors often prescribe OTC eye drops and corticosteroids depending on the condition’s stage. If the disease was at an advanced stage, surgery would be the only other choice. 

Biopharmaceutical company Horizon Therapeutics announced in 2020 its new drug called Tepezza. It marked the first FDA-approved treatment for TED. Hailed as a wonder drug, Tepezza was effective in treating the signs and symptoms of TED.

Patients then reported experiencing adverse side effects, including hearing loss. Many have filed cases, claiming Horizon failed to warn them about Tepezza’s risks. The first round of the Tepezza lawsuit is set for 2026. In this article, we will highlight how this drug has emerged as a health culprit. 

Tepezza Complications

Following the evidence based on two random clinical trials, the FDA approved Tepezza. 

In the same findings presented to the FDA, it was noted that hearing impairment was of concern. Tinnitus and hyperacusis were discovered in up to 10% of patients, the NIH cited the report as saying. Other adverse effects of the treatment were nausea, alopecia, headaches and dry skin.

A follow-up study showed the potential risks of hearing loss were much higher than initially thought. To be exact, about 65% of drug users could face complications.

In response to patient concerns, Horizon added a warning label in 2023. They recommended assessing patients’ hearing before, during, and after treatment, and weighing the treatment’s risks and benefits.

The warning came too late. Patients who had started the medication before 2023 had already started experiencing the effects. 

The crux of the case is that Horizon Therapeutics didn’t provide sufficient warnings about Tepezza’s risks, claims TorHoerman Law.

Product Liability Law

According to Forbes, plaintiffs have the option to sue the drug manufacturer, retailers, and other parties involved. The federal litigation regarding Tepezza-related hearing loss is currently moving towards its initial set of bellwether trials.

Plaintiffs can sue the drug manufacturer, merchants and others responsible for getting the product into their hands, Forbes further reported.

Currently, federal Tepezza hearing loss litigation is progressing towards the first series of bellwether trials.

Amgen’s $27.8 Billion Deal

Last year Amgen completed a $27.8 billion acquisition of Horizon Therapeutics. The sale went through after the FTC approved it on certain conditions. 

The FTC was initially against the acquisition and filed a lawsuit to block the deal. Reuters reported that Amgen is prevented from using anti-competitive tactics to extend the market dominance of Horizon’s Tepezza and Krystexxa drugs.

The antitrust lawsuit called into question the increased oversight acquisitions in the pharmaceutical sector that used consolidation to power future growth. The FTC has now suspended its challenge.

Tepezza’s Pending European Approval

Despite the setbacks and numerous lawsuits, Amgen plans to take Tepezza to Europe, pending approval of the European Medicines Agency.

Market Watch reported there are currently no approved treatments in Europe for Thyroid Eye Disease. New data from a study could also leverage the greenlight.

The data indicated the lasting effects of Tepezza in patients with TED. About 82% of patients in the follow-up didn’t need additional TED treatment, Ophthalmology Times quoted an ENDO press release. The study findings were published in the journal Thyroid.

The report did however note the adverse side effects. Four cases of hyperglycemia were observed during the follow-up. Three were resolved while another was ongoing.

Multidisciplinary Treatment

Researcher Dr Sara T. Wester believes treating Tepezza’s adverse effects should be multidisciplinary. While chatting with Managed Healthcare, Wester said she brings in an audiologist and a GI to “help manage adverse events.” She also does baseline testing of patients diagnosed with diabetes.

A type of infusion therapy, Tepezza is given in one dose every three weeks. The full treatment takes about five months. Because it is administered as an IV, Wester said doctors have to be thinking about systematic implications, especially in the field of ophthalmology.

A December 20, 2024 deadline has been to conclude fact discovery. While anxious plaintiffs await the onset of the trial, Tepezza is still being widely used. Hopefully, the outcome of the Tepezza hearing loss lawsuits will affect how and when the drug is suitable for safe use.