Thyroid Eye Disease (TED), also known as Graves' orbitopathy, is a serious autoimmune condition characterized by inflammation and swelling of the tissues behind the eyes. This can lead to eye bulging (proptosis), double vision (diplopia), pain, and vision loss. For decades, treatments were limited to managing symptoms with corticosteroids or resorting to surgery once the disease was inactive. The arrival of teprotumumab has revolutionized the treatment landscape by offering a targeted, medical solution.
How Tepezza works: A targeted approach
Tepezza is a fully human monoclonal antibody that acts as an inhibitor of the insulin-like growth factor-1 receptor (IGF-1R). The IGF-1R plays a crucial role in the development of TED, as autoantibodies activate this pathway on orbital fibroblasts behind the eye. By blocking this pathway, Tepezza helps reduce inflammation, preventing the swelling of muscles and fat tissue and the tissue expansion that causes the eyes to bulge. This is a more targeted approach compared to broad immune suppression with steroids or surgical interventions that address mechanical issues without treating the underlying cause.
Clinical effectiveness and outcomes
Clinical trials, such as the Phase 3 OPTIC trial, have shown Tepezza's effectiveness in treating moderate-to-severe TED. A significant percentage of patients treated with Tepezza experienced a reduction in proptosis and improvement in double vision. While initial results were positive, some studies indicate potential for disease recurrence after treatment. However, others show long-term response is possible, and re-treatment can be effective. The overall success can vary depending on individual factors, highlighting the need for further research.
Administration and treatment schedule
Tepezza is given intravenously (IV) over several months. Patients receive eight infusions, one every three weeks. The first two infusions take longer than subsequent ones. Infusions can be done in a medical setting or potentially at home.
Important safety information and side effects
Tepezza can cause side effects. A notable risk is hearing impairment, including hearing loss and tinnitus, with recent data suggesting a higher incidence than initially thought. The FDA updated its warning on hearing issues in 2023. High blood sugar (hyperglycemia) is another risk, particularly for diabetic patients who need close monitoring. Infusion reactions can also occur. Patients with inflammatory bowel disease should be watched for flare-ups. Other reported side effects include muscle spasms, nausea, and fatigue.
Comparison of TED Treatments
| Feature | Teprotumumab (Tepezza) | Corticosteroids | Surgery | Other Biologics/Emerging Treatments |
|---|---|---|---|---|
| Mechanism | Targets and blocks IGF-1R, addressing the root cause of inflammation. | Broadly suppresses the immune system to reduce inflammation. | Corrects structural changes and relieves pressure, but doesn't treat the disease process. | Target other pathways like IL-6 or FcRn. |
| Primary Effect | Effectively reduces proptosis (eye bulging) and diplopia. | Moderately reduces inflammation and symptoms, with limited impact on proptosis. | Reduces proptosis by removing bone and tissue; can correct double vision and eyelid retraction. | Varying efficacy on different symptoms depending on the target. |
| Administration | Intravenous (IV) infusions every 3 weeks for 8 doses. | Oral tablets or IV infusions for a limited course. | Surgical procedures, often done after inflammation subsides. | Subcutaneous or oral options being explored in trials. |
| Side Effects | Hearing impairment, hyperglycemia, infusion reactions. | Weight gain, mood swings, hypertension, metabolic issues. | Risk of infection, changes in appearance, new or persistent double vision. | Side effects vary by drug; monitoring is required. |
| Disease Stage | Approved for active and chronic TED. | Primarily for the active, inflammatory phase. | Performed primarily in the inactive, stable phase. | Various stages, depending on the specific trial. |
Emerging therapies and the future
Research for new TED treatments is ongoing, with several potential drugs in development, including oral and subcutaneous options for easier administration. Some therapies currently in clinical trials are:
- Veligrotug (VRDN-001): Another IV IGF-1R antibody with positive Phase 3 results.
- Linsitinib: An oral IGF-1R inhibitor.
- FcRn inhibitors: These aim to reduce harmful antibodies.
- IL-6 antagonists: These target the IL-6 cytokine.
The patient journey with Tepezza
The process for starting Tepezza involves consulting with a TED specialist for evaluation. Treatment requires close monitoring over approximately six months, including checks on blood sugar and hearing. Follow-up after treatment is necessary to watch for recurrence. While effective, some patients may need further treatment or surgery.
Conclusion
For those asking 'what is the new drug for TED', Tepezza (teprotumumab), approved in 2020, stands out as a targeted treatment for Thyroid Eye Disease, addressing the root cause of inflammation. While it carries potential risks like hearing issues, studies demonstrate its effectiveness in reducing symptoms like eye bulging. The development of new therapies indicates a promising future for TED treatment. Best outcomes with Tepezza and other emerging drugs rely on early diagnosis, careful patient selection, and ongoing monitoring.
