An article published in World Pharmaceutical Frontiers revealed that it's one of the five drugs approved for use in the country this September.
This is a big deal-not only for Amgen, a global biotech giant, but also for patients in Japan who have long needed better options for managing this rare condition. This approval offers new hope as it will provide targeted treatment for a disease that often leaves patients with limited choices.
This isn't just a regulatory win. Rather, it marks significant progress in providing access to innovative, life-changing treatments for TED patients in Japan.
Thyroid eye disease, Cleveland Clinic explains, is an eye disorder that causes inflammation and injury to the surrounding tissues of the eyes. These include fatty tissue, connective tissue, and muscles.
This condition-also known as Graves' disease-occurs when the protective immune system attacks the body.
TED, or thyroid eye disease, is a rare condition, however. It has an incidence rate of nearly 19 in 100,000 people per year. The average age for a TED diagnosis is 43 years.
The signs and symptoms of TED include red eyes, bulging eyes, double vision (diplopia), and dry and watery eyes.
Unlike traditional approaches that primarily address symptoms, Tepezza targets the root cause of the disease.
How does it work? This drug blocks the insulin-like growth factor-1 receptor (IGF-1R) in cells behind the eyes, which triggers inflammation and tissue growth. This helps reduce swelling and bulging associated with TED.
Clinical trials have shown impressive results. A study published by NIH revealed that Tepezza reduced diplopia in about 58%, or 11 out of 19, patients.
Another small study of 31 patients found that 28 patients noticed reduced eye bulges in their more severe eyes. In addition, 10 out of 15 patients reported improvements in double vision, whereas the double vision of 8 out of 15 patients completely went away.
After taking Tepezza, 28 out of 31 patients had little to no swelling, redness, or eye pain. For 18 out of 31 patients, these symptoms disappeared totally.
The OPTIC-J phase 3, randomized, double-masked, placebo-controlled, parallel-group, multicenter study assessed the efficacy, tolerability, and safety of Tepezza in treating patients with active TED in Japan.
In Japan, this drug was designated as an orphan drug, which shortened the regulatory review period to 9 months instead of the standard 12 months.
Improvement in proptosis was the study's primary endpoint. Fortunately, this was met. At week 24, proptosis improved by 2 mm or more in about 89% of patients treated with Tepezza, compared with the placebo at 11%. This result was statistically significant (p<0.0001).
One of the main warnings is that Tepezza can cause infusion reactions. About 4% of people who received this drug reported experiencing it. These are often mild to moderate in severity.
Possible signs of infusion reactions include temporary blood pressure spikes, hot flashes, rapid heartbeat, shortness of breath, headache, and muscle pain.
This drug can exacerbate pre-existing inflammatory bowel disease (IBD). Hyperglycemia or a spike in blood glucose may occur in patients treated with Tepezza.
The most concerning side effect linked to Tepezza is hearing impairment, however.
An article published in JD Supra revealed that potentially irreversible hearing loss is one of the most alarming side effects of Tepezza. Researchers of a groundbreaking study from Stanford University reported that 65% of users developed hearing disorders after taking the medicine.
Specifically, 29% reported heightened hearing of their voice, 27% developed tinnitus, 23% experienced subjective hearing loss, and 12% felt ear plugging sensations.
This has led to a wave of the Tepezza hearing loss lawsuit claims. Patients are suing the manufacturer for failing to adequately warn them about the severity and permanence of these auditory side effects.
Note that Amgen is not the defendant in the suit. Rather, Horizon Therapeutics is.
Amgen completed its acquisition of Horizon Therapeutics only last year, whereas people started filing Tepezza lawsuits in 2022. Hence, Horizon Therapeutics is the defendant in the lawsuit.
As far as compensation is concerned, TorHoerman Law says that lawyers estimate it could reach over $200,000. As these legal challenges unfold, both doctors and patients must weigh the drug's benefits against its potential risks.
The approval of Tepezza in Japan is a significant milestone not only for Amgen, but for the entire field of ophthalmology and autoimmune disease treatment. For patients living with TED, the availability of Tepezza offers new hope. It highlights how medical innovation can truly impact even the most rare and challenging diseases.