Amgen Launches Tepezza in South Korea for Thyroid Eye Disease

Amgen Korea has launched Tepezza (teprotumumab) in South Korea, marking the country's first approved targeted treatment for thyroid eye disease (TED).

The company highlighted the clinical significance of the launch at a press conference in Seoul, bringing together Korean and U.S. specialists to discuss how targeting the underlying disease pathway could change treatment for moderate-to-severe TED.

Ted is a rare autoimmune disorder that causes inflammation and structural changes in the muscles and tissues surrounding the eyes, leading to symptoms such as proptosis (bulging eyes), eyelid retraction, double vision, and impaired vision. Around 2,000 people in Korea are estimated to have moderate-to-severe TED.

Until now, treatment has primarily focused on controlling inflammation with therapies such as high-dose corticosteroids during the active phase of the disease, followed by surgery. Tepezza, however, targets insulin-like growth factor-1 receptor (IGF-1R), which is involved in a key signaling pathway implicated in the development of TED.

Professor Yoon Jin-sook of Severance Hospital presented results from the phase 3 OPTIC trial involving 83 adults with active moderate-to-severe TED. At week 24, 83 percent of patients receiving Tepezza achieved a reduction in proptosis of at least 2 millimeters, compared to 10 percent in the placebo group.

The introduction of Tepezza has shifted thyroid eye disease treatment in the U.S. toward earlier disease-modifying intervention, with improvements in proptosis, diplopia, and visual function changing how physicians consider the need for subsequent surgical treatment.