How does Tepezza work, what's the mechanism of action?

Tepezza (teprotumumab) is a targeted biologic inhibitor of insulin-like growth factor-1 receptor (IGF-1R) and is used to treat Thyroid Eye Disease (TED). Tepezza helps to decrease eye bulging (proptosis) by decreasing inflammation, preventing muscle and fat tissue remodeling, and preventing tissue expansion behind the eye. It is a fully human monoclonal antibody and blocks IGF-1R activation and signaling, but its mechanism of action is not fully known.

Tepezza is given by a healthcare provider as an intravenous (IV) infusion into a vein once every three weeks for a total of eight infusions.

What is Thyroid Eye Disease?

• Thyroid Eye Disease (TED) is a rare and serious autoimmune disease that can cause proptosis (eye bulging), diplopia (double vision), blurred vision, pain, inflammation and facial disfigurement. Thyroid Eye Disease may also be called Graves Eye Disease.
• TED is caused by autoantibodies activating an IGF-1R-mediated signaling complex on cells within the retro-orbital space (behind the orbit of the eye).
• TED often occurs in people living with hyperthyroidism or Graves’ disease. This leads to a cascade of negative effects, which may cause long-term, irreversible damage, including eventual blindness.

How well does Tepezza for Thyroid Eye Disease work?

In January 2020, Horizon Therapeutics announced the FDA approval of Tepezza for the treatment of Thyroid Eye Disease (TED), and it is the first and only approved agent for this condition.

• Approval was based on the OPTIC study which found a significant improvement (82.9%) in proptosis (eye bulging) compared to a placebo (inactive) treatment (9.5%).
• Secondary endpoints were also met, including diplopia (double vision) improvements.

In studies, the most common side effects occurring in 5% or more of patients were:

• muscle spasm
• nausea
• alopecia (hair loss)
• diarrhea
• fatigue
• hyperglycemia (high blood sugar)
• hearing impairment
• dysgeusia (altered taste)
• headache
• dry skin.

Bottom Line

• Tepezza (teprotumumab) from Horizon Therapeutics is a targeted biologic inhibitor of insulin-like growth factor-1 receptor (IGF-1R) used to treat Thyroid Eye Disease (TED). It is a fully human monoclonal antibody and blocks IGF-1R activation and signaling.
• Tepezza is the first and only approved agent for the treatment of Thyroid Eye Disease (TED).
• It is given by an intravenous (IV) infusion into a vein once every three weeks for a total of eight infusions.

This is not all the information you need to know about Tepezza (teprotumumab-trbw) for safe and effective use. Review the full Tepezza information here, and discuss this information and any questions you have with your doctor or other health care provider.