Thyroid Eye Disease (TED), a serious, progressive, vision-threatening rare autoimmune disease that affects a small patient population, causes serious damage including proptosis (eye bulging), strabismus (misalignment of the eyes) and diplopia (double vision), and in some cases can lead to blindness. Until the FDA approval of TEPEZZA, TED patients had no approved options for treatment and received palliative therapy. Patients had to live with the condition until the inflammation subsided, after which they were often left with permanent vision-impairing consequences. Multiple complex surgeries were often required for TED patients. In order to combat this disease, Horizon developed TEPEZZA and took the unique approach of educating health care practitioners on its use as a biologic. With a 6-month course of TEPEZZA showing long-term durability, the novel infused biologic therapy administered to patients once every three weeks – a total of eight infusions – demonstrated strong efficacy, with 82.9% of patients achieving needed proptosis reduction. Only 11 days after TEPEZZA was approved, the first patient was treated, beginning a new era in TED treatment.