Annual sales of 13.1 billion yuan in products, new Phase 3 clinical trial success

Ask AI · How Can a Subcutaneous Dosage Form Revolutionize the Treatment Experience for Thyroid Eye Disease?

On April 6, Amgen announced that TEPEZZA, its blockbuster drug with 2025 sales of $1.903 billion (about RMB 13.1 billion), achieved positive topline results in a Phase 3 clinical trial using a subcutaneous administration regimen, demonstrating effectiveness comparable to that of an intravenous infusion dosage form.

The results of this randomized, double-blind, placebo-controlled Phase 3 trial showed that during the 24-week treatment period, the exophthalmos improvement rate in the TEPEZZA OBI group was as high as 77% (76.7% vs 19.6% in the placebo group, p<0.0001). The average exophthalmos retraction was 3.17 millimeters (vs 0.80 millimeters in the placebo group, p<0.0001). This data was comparable to the efficacy of the already approved intravenous infusion dosage form, validating the feasibility of the subcutaneous administration route.

The overall safety results observed in the trial were broadly consistent with the known safety profile of TEPEZZA intravenous infusions. Some patients experienced mild to moderate injection-site reactions, but these did not lead to treatment interruption or discontinuation. The most common adverse events (≥10%) included muscle spasms, tinnitus, weight loss, ear discomfort, nausea, and diarrhea.

It is worth noting that the currently approved TEPEZZA is administered via intravenous infusion, requiring patients to receive 8 infusions at a medical institution (once every 3 weeks). By contrast, the new OBI patch-style injector allows patients to self-administer via subcutaneous injection every two weeks, for a total of 12 injections, without the need for frequent visits to the hospital.

This dosing innovation is expected to significantly improve the patient treatment experience. Thyroid eye disease is a serious autoimmune condition that severely affects quality of life. Patients often face both physical and psychological burdens due to symptoms such as exophthalmos, double vision, and eye pain. The development of a subcutaneous dosage form extends the treatment setting from hospitals to home, reducing patients’ time and energy costs from traveling to medical institutions and providing a more flexible option for disease management.

TEPEZZA is the first approved IGF-1R antibody drug worldwide for the treatment of thyroid eye disease. Since its U.S. approval in January 2020, it has treated more than 25,000 patients globally. In October 2023, after Amgen acquired Horizon Therapeutics for $27.8 billion, TEPEZZA was incorporated into its product portfolio. In full-year 2025, TEPEZZA sales reached $1.903 billion (about RMB 13.1 billion), up 3% year over year.

TEPEZZA has been approved for indications

Image source: Pharma Intelligence Data—Global Drug Analysis System

The successful Phase 3 clinical trial of this subcutaneous dosage form will build new competitive barriers for TEPEZZA. At present, in the global TED treatment space, multiple IGF-1R antibodies are in clinical development, including Viridian’s VRDN-001 (intravenous) and VRDN-003 (subcutaneous), as well as IBI311 from Innovent Biologics, among others. Differences in dosing convenience and safety profile will become key factors in differentiated competition.

Conclusion: The successful Phase 3 clinical trial of TEPEZZA’s subcutaneous dosage form marks a new stage in thyroid eye disease treatment—one where efficacy and convenience are both achieved. For a blockbuster with annual sales of RMB 13.1 billion, this is not just a simple improvement in the dosing method, but a model of product lifecycle management driven by a patient-centered concept. Against the backdrop of increasingly fierce competition in the treatment of autoimmune diseases, enhancing patient adherence through dosage form innovation and expanding market coverage have become critical strategies for maintaining a drug’s long-term competitiveness.

Reference sources:

1. Pharma Intelligence Data—Global Drug Analysis System

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