Amgen announced on Apr. 7 that a new subcutaneous formulation of its thyroid eye disease drug, Tepezza, performed as well as the currently approved intravenous version in a late-stage clinical trial.
The development is important because it could make treatment more convenient for patients and potentially help boost sales of Tepezza, which have been stagnant. Analysts from William Blair said, “We believe that the availability of the SC [subcutaneous] option could help the Tepezza franchise return to growth” in thyroid eye disease. Leerink Partners analysts also said that Amgen’s results with the new formulation could drive greater use due to increased convenience.
In recent financial results, Amgen reported that Tepezza sales fell by 1% to $457 million in the fourth quarter of 2025 compared to $460 million during the same period in 2024. However, full-year revenues grew by 3% to $1.9 billion from $1.85 billion previously. Leerink projected global sales could reach $2 billion this year.
According to topline data released Monday, subcutaneous Tepezza using Amgen’s on-body injector achieved a proptosis response rate—referring to improvement in abnormal bulging of eyes—of nearly 77% over a period of 24 weeks, while placebo achieved about 20%. The effect was described by Amgen as “statistically significant and clinically meaningful.” The new formulation also showed improvements across other measures such as double vision and quality of life.
William Blair analysts said that “the SC Tepezza results are encouraging,” adding that efficacy “looks in line” with intravenous dosing. They also noted benefits appeared greater than those seen with Viridian Therapeutics’ TED drug candidate elegrobart, which recently reported lower response rates in its own trials.
Looking ahead, William Blair wrote that both Viridian’s elegrobart and Amgen’s new version of Tepezza "could usher in a new era for the TED space," especially since easier administration may expand treatment options for patients who have had limited choices until now.
