Tepezza Hearing Loss Lawsuit MDL 3079 — 2026 Plaintiff Guide

The promise of Tepezza was real: the first drug capable of reversing thyroid eye disease without surgery or radiation. For patients who had spent years managing painful proptosis, double vision, and the threat of vision loss, FDA approval in January 2020 represented a genuine medical breakthrough.

The problem that emerged afterward was also real — and for some patients, permanent.

MDL 3079, In re: Tepezza Marketing, Sales Practices, and Products Liability Litigation, was formally established in June 2023 in the Northern District of Illinois. Plaintiffs allege that Horizon Therapeutics — now a subsidiary of Amgen — knew about the risk of serious hearing impairment before and after FDA approval but failed to adequately warn prescribers and patients. For some, the consequences have been irreversible sensorineural hearing loss and chronic tinnitus.

This guide is for patients who received Tepezza and subsequently developed hearing problems. It covers the drug’s background, the legal theory of the case, who qualifies, what to document, and how to evaluate an MDL attorney. This is not medical or legal advice; your personal situation requires consultation with a licensed physician and a qualified mass tort attorney.

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Thyroid Eye Disease and Why Tepezza Matters

What Thyroid Eye Disease Does to Patients

Thyroid eye disease (TED) is an autoimmune condition that causes the immune system to attack tissues behind the eye. In Graves’ disease, the most common associated condition, the same antibodies that attack the thyroid gland also target orbital fibroblasts, causing inflammation, fat and muscle expansion, and eventual fibrosis in the eye socket.

The clinical consequences range from uncomfortable to debilitating:

• Proptosis — the eyes push forward out of the orbit
• Diplopia — double vision from muscle restriction
• Orbital pressure and pain — burning, tearing, photosensitivity
• Corneal exposure — incomplete eyelid closure can damage the cornea
• Dysthyroid optic neuropathy — in severe cases, compressive optic nerve damage causing vision loss

Before Tepezza, treatment options were limited to high-dose steroids (with systemic side effects), orbital radiation, and surgical decompression — all targeted at managing rather than reversing the disease process.

Tepezza’s Mechanism and Clinical Results

Tepezza (teprotumumab-trbw) works by blocking the IGF-1R receptor, which plays a central role in the inflammation and fibrosis driving TED. In pivotal clinical trials, the drug demonstrated statistically significant reductions in proptosis and clinical activity score compared to placebo — something no prior treatment had achieved.

The FDA granted orphan drug status and approved Tepezza on January 21, 2020, making it the first and only FDA-approved treatment specifically for active TED. At approximately $120,000 for the standard eight-infusion course, it became one of the most expensive treatments in specialty medicine — and one of the most commercially significant launches for Horizon Therapeutics.

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The Hearing Loss Problem: What the Science Shows

What the FDA Label Currently Says

The Tepezza prescribing information updated in 2023 includes the following key language:

In Warnings and Precautions: “TEPEZZA may cause severe hearing impairment including hearing loss.” Monitoring for hearing changes during treatment is recommended.

In Adverse Reactions: Hearing impairment appears as an adverse reaction with greater than 5% incidence — grouped with muscle spasm, nausea, alopecia, hyperglycemia, and other reactions from the clinical trial data.

Recommended monitoring: Baseline audiogram before treatment, with periodic audiograms during the treatment course.

This label language represents an acknowledgment that the risk is real and clinically significant. But the litigation centers on whether this language appeared in adequate form when the drug was first approved and in the years immediately following.

The Gap Between Early and Later Labeling

The first Tepezza prescribing information approved in January 2020 did not include the explicit “severe hearing impairment” warning that appears in the 2023 label. The FDA application number 761143 has received multiple supplemental label updates since 2020.

Plaintiffs argue that clinical trial data available at or before the time of approval showed approximately 10% of participants experienced hearing-related symptoms — a signal that warranted a more prominent warning from the outset. Independent research published post-approval has reported rates of subjective hearing symptoms in treated patients substantially higher than trial data, with one study finding rates approaching 81.5%.

The central legal question: did Horizon have a duty to update its label sooner, and more prominently, before the 2023 revision?

Horizon’s initial legal defense argued that FDA regulations require prior approval for unilateral label changes, limiting what manufacturers can do independently. Courts have addressed this defense in pharmaceutical failure-to-warn cases in various ways, including through the “changes being effected” (CBE) supplement pathway that allows certain safety-related label changes without prior FDA approval.

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The Defendants: Horizon Therapeutics and Amgen

Horizon Therapeutics was an Irish-incorporated specialty pharmaceutical company focused on rare and rheumatic diseases. Tepezza was its most commercially significant product, driving the majority of the company’s revenue growth from 2020 onward.

Amgen completed its acquisition of Horizon Therapeutics, making Horizon a wholly owned Amgen subsidiary. The acquisition made Amgen one of the largest specialty biotech companies in rare disease.

The legal significance: post-acquisition, Amgen bears successor liability for claims arising from Tepezza’s pre-acquisition marketing and labeling practices. Horizon remains the named defendant in most MDL 3079 complaints, but settlement negotiations and any eventual judgment will effectively involve Amgen’s legal and financial resources.

This structure — where a large acquirer inherits mass tort exposure from an acquired company — has appeared in other pharmaceutical litigations, and typically results in the acquirer driving settlement negotiations given its greater financial capacity and reputational interest in resolution.

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MDL 3079 Case Timeline and Status

Milestone	Date / Status
First individual lawsuit filed	August 2022
MDL 3079 formally established	June 2023, ND Illinois
Bellwether deadlines	Struck October 2025, suggesting possible settlement discussions
Trial date previously discussed	August 2026 (current status pending)
Settlement	None announced as of May 2026
Active MDL track	Personal injury (hearing loss, tinnitus)

The striking of bellwether deadlines is a recognized procedural signal in MDL management — it typically means either settlement discussions are progressing enough that a trial date is not immediately needed, or the parties need more time for case-specific discovery. It does not mean settlement is imminent.

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Patient Profile: Who Has a Viable Claim

Core Eligibility Criteria

For a personal injury claim in MDL 3079, the following elements are generally needed:

1. Tepezza infusions received — At least one infusion of teprotumumab-trbw for a TED diagnosis
2. Auditory adverse event — Development of sensorineural hearing loss, tinnitus, ear fullness, or autophony during or following treatment
3. Temporal connection — Symptoms beginning during the treatment course or within a reasonable period after completion
4. Absence of dominant alternative cause — No pre-existing severe hearing impairment or clear alternative explanation

Audiological Evidence Is Central

Unlike many drug injury cases where a diagnosis speaks for itself, hearing loss claims are heavily evidence-dependent. The presence or absence of a pre-treatment baseline audiogram can make or break a case:

With a baseline audiogram: Documented change from pre-treatment to post-treatment provides objective evidence of hearing deterioration attributable to the treatment period.

Without a baseline audiogram: Claims can still be made using age-corrected normative data, otolaryngologist testimony, and the patient’s subjective history — but they are harder to defend against defense challenges.

The FDA label’s own recommendation for baseline audiograms was not consistently implemented in clinical practice during the early years of Tepezza availability. This gap — patients being treated without pre-treatment hearing baselines — itself may be a medico-legal issue.

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Three Patient Scenarios

These scenarios are fictional, not legal advice.

Scenario 1: Progressive Tinnitus During Treatment

A 54-year-old woman in New Jersey with Graves’ disease received all eight Tepezza infusions in 2022. Starting with infusion five, she developed progressive high-pitched tinnitus. A post-treatment audiogram showed high-frequency sensorineural hearing loss not present on her pre-treatment baseline. Two years later, the tinnitus remains constant and affects her sleep and work.

This profile presents strong case elements: covered drug, temporal correlation, baseline comparison showing objective change, persistent and documented injury. MDL 3079 claim evaluation is strongly warranted.

Scenario 2: Hearing Loss Discovered Later at Routine Exam

A 62-year-old man in Florida completed Tepezza treatment in 2021. No auditory symptoms were noted at the time. At a routine physical in 2022, audiometry showed bilateral high-frequency hearing loss that his audiologist noted was beyond age-expected norms. No baseline audiogram was taken before treatment.

The absence of a baseline complicates but does not eliminate the case. The key question is whether the degree and pattern of loss is consistent with what has been documented in Tepezza clinical studies. Expert audiological testimony will be essential. The discovery rule means the statute of limitations likely started in 2022 when the loss was identified.

Scenario 3: Tepezza Treatment With No Auditory Symptoms

A patient who received Tepezza but reports no hearing changes has no current personal injury claim basis. The appropriate step is maintaining regular audiological monitoring with their physician and documenting any future changes.

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Document Checklist

Document Type	Details	Priority
Tepezza prescription records	Prescribing physician, infusion dates, doses	Critical
Pre-treatment audiogram	Baseline hearing test results	Critical
Post-treatment audiograms	Any hearing tests after infusion started	Critical
Tinnitus/symptom diary	Date symptoms began, severity log	High
Otolaryngology / ENT records	ENT evaluation and recommendations	High
Medical records (TED diagnosis)	Original TED diagnosis and treatment records	Supporting
Insurance billing	Tepezza infusion claims	Supporting

If you don’t have a baseline audiogram, ask your current physician to document your hearing status now and to note the history of Tepezza treatment.

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Finding the Right MDL Attorney

Tepezza MDL 3079 requires specific expertise in pharmaceutical failure-to-warn litigation — a distinct subspecialty within mass tort law. The case involves:

• FDA regulatory history and label change procedures
• Clinical pharmacology of IGF-1R inhibition
• Audiology expert witnesses (audiologists, otolaryngologists, neuro-otologists)
• Successor liability analysis for post-acquisition defendants

What to verify when consulting an attorney:

• Confirmed cases in MDL 3079 specifically (not just pharmaceutical litigation generally)
• Access to audiology expert network
• Contingency fee structure with no upfront payment
• Free initial consultation
• Will explain whether your case is a strong, moderate, or weak candidate honestly

For context on contingency fee structures, see personal injury attorney fees 2026. For understanding how MDL settlement timelines typically progress from establishment to payout, see mass tort settlement payout timelines 2026.

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The Regulatory Pathway: Why Labels Are Hard to Update Unilaterally

A recurring defense argument in pharmaceutical failure-to-warn cases is that the FDA controls drug labeling and manufacturers cannot simply add or change warnings without regulatory approval. This defense deserves careful examination.

The FDA’s “changes being effected” (CBE-0) regulation, codified at 21 C.F.R. § 314.70(c), allows manufacturers to make certain labeling changes — specifically, additions or changes to strengthen a contraindication, warning, precaution, or adverse reaction — before receiving FDA approval. The change must be submitted simultaneously with implementation and is subject to subsequent FDA review and potential rejection.

The U.S. Supreme Court addressed the interaction between this regulatory pathway and state tort law in Wyeth v. Levine (2009). The Court held that the FDA’s approval of a drug label does not automatically preempt state tort claims for inadequate warnings, because the CBE pathway means manufacturers retain independent legal authority to strengthen warnings. Where a CBE pathway was available, courts have generally held that manufacturers can be found liable under state law for failing to use it.

In MDL 3079, this framework is directly relevant: plaintiffs will argue that Horizon had clinical data indicating elevated hearing risk well before the 2023 label revisions, and that the CBE pathway was available to strengthen the hearing impairment warning at any point after that data became available. Horizon’s defense will focus on whether the data threshold for triggering a CBE-justified warning was actually met at the relevant time.

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The Cost Factor: $120,000 Per Treatment Course and Insurance Implications

Tepezza’s approximately $120,000 per standard course price point is not incidental to the litigation — it shapes several aspects of the claims.

Coverage demographics. At that price point, Tepezza is almost exclusively paid for by commercial insurance, Medicare, or Medicaid. The out-of-pocket cost for most uninsured patients would have been prohibitive. This means that the documented Tepezza patient population is largely insurable-income-bracket adults whose economic loss claims (if hearing impairment affects employment) are more quantifiable than lower-income populations.

Insurance subrogation. Insurers who paid for Tepezza treatment may assert subrogation claims against any settlement fund — meaning they want repayment from settlement proceeds for their claim costs. Patients on Medicare face Medicare Secondary Payer Act considerations that require Medicare’s expenditure on related hearing care to be reimbursed from any settlement. MDL attorneys experienced in pharmaceutical cases understand these lien issues; general personal injury attorneys often do not.

Damages calculation. For plaintiffs with permanent hearing loss, damages include not only past medical expenses but the projected future cost of hearing aids, audiological care, cochlear implant candidacy evaluation, and hearing rehabilitation — all of which need to be documented by expert testimony and documented in plaintiff discovery.

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The Amgen Acquisition: Scale and Settlement Dynamics

Amgen’s acquisition of Horizon Therapeutics fundamentally altered the financial dynamics of MDL 3079 in ways that favor plaintiffs.

Horizon as a standalone company had meaningful but limited financial resources to support a multi-billion-dollar mass tort settlement. Amgen, as one of the world’s largest biotechnology companies by market capitalization, has substantially greater capacity to fund a comprehensive resolution.

The acquisition also brings different strategic priorities. For a specialty pharma company like Horizon, Tepezza represented the majority of its revenue — and reputational damage from the litigation could directly harm its core business. For Amgen, which has a diversified portfolio across oncology, cardiovascular, and rare disease, Tepezza is an important but not existential asset. Amgen can absorb a large settlement without the same level of existential threat.

This dynamic typically accelerates settlement timelines in post-acquisition MDL situations. The acquiring company often has both the financial capacity and the strategic incentive (removing litigation uncertainty, moving on) to reach earlier resolution than the original defendant might have.

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Comparison to Other Pharmaceutical Failure-to-Warn Litigations

MDL 3079’s legal theory — that a manufacturer knew of a serious adverse event risk, underrepresented it in initial labeling, and failed to promptly update warning language — follows the pattern of other pharmaceutical mass torts:

Parallel to hearing in other drug litigations: Aminoglycoside antibiotics, cisplatin-based chemotherapy, and quinine have all been subjects of litigation involving drug-induced hearing loss. The difference with Tepezza is the rare disease context and the unusually high drug cost, which concentrates the exposure among a definable patient population.

Successor liability precedent: Pharmaceutical acquisitions where the acquirer inherits MDL exposure include multiple recent examples. Courts have consistently held that merger and acquisition transactions do not extinguish preexisting tort liability.

Related pharmaceutical and medical device litigation updates can be found in our coverage of Bard PowerPort catheter lawsuits and hernia mesh lawsuits.

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How Sensorineural Hearing Loss Damages Are Calculated

One of the distinguishing features of MDL 3079 personal injury claims is that sensorineural hearing loss creates quantifiable and documented future damages with a long projection horizon. Understanding how these damages are typically calculated helps plaintiffs assess the potential value of their claims.

Medical expense damages include: past and future audiological evaluations, hearing aids (average lifespan 5–7 years; cost $3,000–$8,000 per pair; replaced multiple times over a lifetime), auditory rehabilitation therapy, cochlear implant candidacy evaluation (if loss is severe enough), cochlear implant surgery if appropriate ($30,000–$100,000+, partially covered by insurance), and ENT follow-up visits.

Pain and suffering / non-economic damages are typically calculated by the jury based on the severity and permanence of the impact on daily life. Factors that increase non-economic damage awards include: bilateral (both ears) rather than unilateral loss, professional impact (musicians, teachers, physicians, anyone for whom hearing is central to their career), tinnitus that affects sleep and concentration, and younger age at onset (greater remaining years of impact).

Lost income damages apply when the hearing loss prevented or limited the plaintiff’s ability to continue their occupation or perform at the same level. This requires occupational expert testimony and documented employment history.

Loss of enjoyment of life is a separate damages category in many states, covering the inability to enjoy activities that previously brought pleasure — music, conversation, social gatherings — following permanent hearing impairment.

An experienced MDL attorney will work with vocational rehabilitation experts, audiologists, and medical economists to produce a comprehensive damages analysis — the foundation for any settlement negotiation.

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The Rarity of Tepezza’s Patient Population: Why It Matters Legally

Thyroid eye disease affects an estimated 15–40 people per 100,000 in the general population. At this prevalence, the total universe of active Tepezza patients at any given time is relatively small — meaning MDL 3079 will never have the 10,000+ case volume of something like the Philips CPAP litigation or the talcum powder MDLs.

This smaller case volume has important strategic implications:

Higher individual case value potential. With fewer cases and well-documented patient populations (TED is a diagnosed specialty condition with clear treatment records), each case is more susceptible to full individualized analysis. Settlement matrices can be more granular, and cases with severe hearing loss may command individually negotiated resolution at higher values.

Greater expert testimony investment per case. In large-volume MDLs, economics push toward standardized damages matrices. In smaller MDLs, individualized expert work plays a relatively larger role, which benefits plaintiffs with stronger evidence profiles.

Earlier settlement feasibility. With a smaller case pool, global resolution (complete MDL settlement) is logistically achievable more quickly than in 10,000-case MDLs. Both sides — defendants managing Amgen’s corporate exposure and plaintiffs seeking resolution — may have stronger incentives to reach comprehensive early agreement.

The MDL 3079 case count, while not publicly reported with precision as of May 2026, is understood to be in the hundreds rather than thousands — a profile consistent with the limited patient population of a rare disease treatment.

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How the Tepezza MDL Statute of Limitations Works in Practice

The statute of limitations for Tepezza hearing loss claims is governed by state law, with the discovery rule applying in most jurisdictions. For many patients, this means:

• The clock does not start running when you received your first infusion
• It starts when you knew or reasonably should have known that your hearing loss or tinnitus was connected to Tepezza treatment
• If you were told your hearing effects were “temporary” and later discovered they were permanent, the clock may start at the point of that discovery

Practical examples:

A patient in New Jersey who completed Tepezza in March 2022 and was told by her ENT in September 2023 that her tinnitus was likely permanent: her discovery date for limitation purposes may be September 2023. New Jersey’s two-year personal injury limitation period would make September 2025 her outside date — not far off if she has not yet consulted an attorney.

A patient in California diagnosed with hearing impairment three months after completing treatment in 2021: California’s two-year limitation period from discovery means the window could be running now.

Do not assume you are time-barred without consulting an attorney. Limitation period analysis in pharmaceutical tort cases involves fact-specific inquiry into what you were told, when, by whom, and what a reasonable person in your situation would have known. This is a legal analysis, not a calendar calculation.

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Audiological Testing Access: What to Ask Your Doctor

For Tepezza patients who want to document their hearing status, here is what to specifically request:

Pure tone audiometry — the standard hearing test measuring threshold sensitivity across frequency ranges. For documenting Tepezza-related hearing loss, high-frequency audiometry (8,000–16,000 Hz) may be particularly relevant, as drug-related ototoxicity often presents first at high frequencies.

Speech recognition testing — measures how well you can understand speech at normal conversational levels. This tests a different aspect of auditory function and is particularly relevant to daily life impact.

Tinnitus evaluation — formal otolaryngology assessment of tinnitus pitch, loudness, and masking level. This converts subjective tinnitus complaint into an objective documented finding.

Vestibular assessment — Tepezza’s effect on the auditory-vestibular system may also affect balance in some patients. If you have experienced new dizziness or balance problems during or after treatment, report this.

If you did not receive a pre-treatment baseline audiogram, your current audiologist can compare your results to age-normative data — the standard audiological hearing for someone your age — which, while less definitive than a direct pre-post comparison, still provides supporting evidence.

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What If You’re Currently Being Treated for TED?

If you are currently receiving Tepezza or your physician has recommended it, this litigation should not be the deciding factor in your treatment decision. That decision belongs to you and your clinical team, who understand your individual TED severity, the risks of leaving TED untreated, and your full medical history.

What you should specifically request regardless of your litigation interest:

1. Pre-treatment baseline audiogram — before your first infusion
2. Mid-treatment audiological check — after infusion four or five
3. Post-treatment audiogram — approximately three months after completing the course
4. Clear documentation if you develop any auditory symptoms during treatment

These steps protect your health. They also create the evidentiary record that matters if a hearing injury occurs.

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Specific Questions for Tepezza Patients

I received Tepezza and have tinnitus, but my ENT says it may be from my thyroid condition, not the drug. Does that mean I have no claim?

Not necessarily. TED and the underlying autoimmune thyroid disease can have their own auditory effects, and this intersection creates genuine medical complexity. However, Tepezza’s documented association with hearing impairment means that the drug-related contribution is a legitimate medical question. A claim does not require proving Tepezza was the sole cause — only that it was a substantial contributing cause. An MDL attorney can assess whether the specific pattern of your symptoms is consistent with Tepezza-related injury and whether expert testimony can support a claim.

I had Tepezza infusions in 2020 before there were any hearing loss warnings at all. Does the absence of early warnings hurt or help my case?

It generally helps your case. If you received Tepezza before the 2023 label revisions that added explicit hearing impairment warnings, you were never informed of the risk. The pre-2023 period is the heart of the failure-to-warn claim — the period when the risk was allegedly known but inadequately disclosed. Patients from this earlier cohort may have the strongest failure-to-warn claims.

I only received three of the eight infusions before stopping because of hearing concerns. Can I still file a claim?

Yes. If you developed hearing impairment or tinnitus with partial treatment and the treating cause was Tepezza, the incomplete course does not eliminate your claim. Indeed, the fact that you stopped treatment because of hearing concerns is itself corroborating evidence of the injury’s temporal connection to the drug.

My doctor denies the hearing loss was from Tepezza. How do I proceed?

Your treating physician’s opinion is relevant but not dispositive in litigation. MDL attorneys retain independent medical experts — otolaryngologists and audiologists who specifically evaluate Tepezza-related hearing claims — who may reach different professional conclusions than your treating physician. If your treatment records, audiogram results, and symptom timeline are consistent with Tepezza-related hearing injury, an independent expert review is appropriate regardless of your treating doctor’s initial assessment.

For context on how pharmaceutical product liability litigation is structured across different drug types, see medical malpractice lawsuits 2026 for related legal analysis.

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Disclaimer: This article is for informational purposes only and does not constitute legal or medical advice. MDL 3079 eligibility, statute of limitations, and potential recovery depend on individual facts that must be evaluated by a licensed attorney experienced in pharmaceutical mass tort litigation. Treatment decisions regarding Tepezza must be made in consultation with your treating physician. No specific outcome or compensation amount is promised or implied.