TEPEZZA® Approved in Japan for Active Thyroid Eye Disease

Amgen, a prominent biotechnology company, has announced that Japan's Ministry of Health, Labour and Welfare (MHLW) has approved TEPEZZA® (Teprotumumab) for treating active or high clinical activity score (CAS) Thyroid Eye Disease (TED). This marks the first approval for TEPEZZA in Asia, providing a new treatment option for a condition that affects roughly 25,000 - 35,000 people in Japan, both in its active and chronic (low CAS) forms.

Thyroid Eye Disease is a severe, progressive autoimmune disorder that can potentially threaten vision. It manifests through symptoms like eye bulging (proptosis), double vision (diplopia), pain, redness, and swelling of the eyes. Prior to the approval of TEPEZZA, treatment for TED primarily involved complex surgeries and high-dose steroids, which brought their own set of complications. TEPEZZA now provides a non-surgical, non-steroidal alternative that targets the underlying cause of the disease.

The expedited approval of TEPEZZA in Japan, which benefited from an orphan drug designation, was based on the promising results of the OPTIC-J trial. This Phase 3 randomized, double-masked, placebo-controlled, multicenter study evaluated the safety, tolerability, and efficacy of TEPEZZA for patients with active TED. Impressively, 89% of patients treated with TEPEZZA showed a clinically meaningful improvement in proptosis compared to just 11% in the placebo group. The safety profile observed was consistent with the comprehensive clinical data supporting TEPEZZA.

A second Phase 3 clinical trial targeting patients with chronic TED and low CAS is currently underway in Japan. This trial aims to further evaluate the efficacy of TEPEZZA, potentially expanding its use to a broader patient base.

Dr. Jay Bradner, Executive Vice President of Research and Development and Chief Scientific Officer at Amgen, highlighted the significance of this approval. He noted that TEPEZZA offers a much-needed alternative to surgeries and steroids, which have been the primary treatment methods to date. The approval of TEPEZZA opens the door for patients to receive treatment directly addressing the root cause of TED without the added risks associated with surgical interventions or high-dose steroids.

Dr. Yuji Hiromatsu from the Kurume University Medical Center and the Shin-Koga Hospital also underscored the importance of this development, pointing out that patients with active TED often face a significant disease burden that can complicate daily activities. The new treatment option aims to alleviate these difficulties by addressing the disease's underlying mechanism.

TEPEZZA is already approved in the United States, Brazil, and the Kingdom of Saudi Arabia, with regulatory reviews ongoing in Europe, Canada, and Australia.

Thyroid Eye Disease is often associated with Graves' disease but is a distinct condition caused by autoantibodies that activate an insulin-like growth factor-1 receptor (IGF-1R) mediated signaling complex in retro-orbital cells. This activation leads to a series of harmful effects that can cause long-term damage, including potential blindness. Symptoms of TED include dry eyes, eye redness and swelling, excessive tearing, eyelid retraction, eye pressure and pain, and double vision.

The approval of TEPEZZA in Japan represents a significant step forward in the global treatment of TED, offering new hope for patients suffering from this debilitating condition.