Amgen Inc.

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Very Bullish +80

Amgen Announces Positive Topline Phase 3 Results For Subcutaneous Tepezza In Adults Living With Moderate-to-severe Active Thyroid Eye Disease

Amgen announced positive topline results from a Phase 3 trial for subcutaneous TEPEZZA in treating moderate-to-severe active Thyroid Eye Disease (TED).

The study demonstrated that the on-body injector version of TEPEZZA achieved comparable efficacy to the existing intravenous formulation.

77% of patients receiving subcutaneous TEPEZZA experienced a highly statistically significant proptosis response compared to 19.6% with placebo over 24 weeks.

The trial met its primary endpoint, showing a clinically meaningful reduction in eye bulging of greater than 3 mm.

Additional secondary endpoints showed improvements including overall responder rates and reductions in double vision and clinical activity scores.

Safety results were consistent with the known profile of intravenous TEPEZZA, with mild-to-moderate injection site reactions as the most common adverse events.

Subcutaneous administration allows for more convenient bi-weekly injections over 12 doses compared to the current IV infusion requirement.

Jay Bradner of Amgen's R&D noted that this delivery method potentially expands access to patients while maintaining best-in-class efficacy.

Dr. Madhura Tamhankar from the University of Pennsylvania highlighted that subcutaneous options make the treatment more accessible for diverse patient needs.

The study included participants with baseline hearing impairment, broadening eligibility for a rare autoimmune condition often linked to Graves' disease.

Full results from this Phase 3 trial will be presented at an upcoming medical congress.

A separate Phase 3b/4 trial to fulfill FDA post-marketing requirements for the IV formulation has also been completed and showed a consistent risk profile.

Bullish Signals
  • Amgen announced positive topline results for Phase 3 trials of subcutaneous TEPEZZA in adults with moderate-to-severe active Thyroid Eye Disease (TED).
  • 77% of patients achieved a highly statistically significant proptosis response rate during the 24-week placebo-controlled period, compared to only 19.6% for placebo.
  • The new subcutaneous formulation delivers IV-level efficacy while offering a more convenient on-body injector administration method that could reach more patients.
  • TEPEZZA OBI showed clinically meaningful improvements across multiple secondary endpoints, including overall responder rates and reduction in double vision (diplopia).
  • The study included up to 25,000 patients worldwide previously treated with IV TEPEZZA, establishing a strong safety baseline for the new subcutaneous option.
  • Safety results were generally consistent with the known profile of TEPEZZA IV, with mild-to-moderate injection site reactions not resulting in treatment interruptions or discontinuations.
Risk Factors
  • While results were positive, the numerical trend favoring TEPEZZA OBI in the visual functioning subscale was not statistically significant at Week 24, leaving some uncertainty about the subcutaneous formulation's impact on functional vision quality.
  • The Phase 3 trial included participants with baseline hearing impairment, and common adverse events included tinnitus and ear discomfort, indicating potential auditory toxicity risks that may limit patient eligibility or cause discontinuation in vulnerable populations.
  • Mild-to-moderate injection site reactions were observed with subcutaneous administration in some patients, suggesting a localized safety profile that differs from the established intravenous formulation and could affect patient tolerance or compliance.
  • The post-marketing requirement study for TEPEZZA IV was conducted to specifically evaluate long-term safety and tolerability across different infusion durations (four, eight, and 16 infusions), implying that extended use profiles are not yet fully characterized or approved.
Full Analysis
Amgen announced positive topline results from a Phase 3 clinical trial for its drug TEPEZZA (teprotumumab-trbw) administered via subcutaneous injection using an on-body injector (OBI). The trial evaluated the efficacy and safety of this new delivery method in adults with moderate-to-severe active Thyroid Eye Disease (TED), a serious autoimmune condition that can cause eye bulging, double vision, and pain. The study met its primary endpoint, demonstrating a statistically significant 77% proptosis response rate over 24 weeks for the TEPEZZA OBI group compared to just 19.6% for the placebo group. This performance is comparable to the existing intravenous (IV) version of TEPEZZA, which has treated more than 25,000 patients worldwide. Secondary endpoints also showed clinically meaningful improvements in overall response rates, reduction in clinical activity scores, and improvements in diplopia and quality of life metrics. Regarding safety, the adverse event profile was consistent with known risks associated with TEPEZZA IV, including muscle spasms, tinnitus, weight loss, and nausea. Mild-to-moderate injection site reactions were observed but did not require treatment interruption. The trial design involved participants receiving injections every two weeks for a total of 12 doses if they received the drug. Additionally, Amgen noted the completion of a separate Phase 3b/4 trial to satisfy FDA post-marketing requirements for the IV formulation, which assessed different treatment durations and retreatment needs. Dr. Jay Bradner of Amgen's R&D department stated that this subcutaneous option aims to provide a more convenient and accessible delivery method while maintaining best-in-class efficacy for this rare disease.