argenx Discontinues Phase 3 UplighTED Studies of Efgartigimod SC in Thyroid Eye Disease Following Futility Analysis
Key Insights
argenx SE (search) announced the discontinuation of Phase 3 UplighTED studies evaluating efgartigimod subcutaneous in adults with moderate to severe thyroid eye disease (search) following an Independent Data Monitoring Committee recommendation for futility.
The decision was based on a pre-specified interim analysis of unblinded data from patients completing 24 weeks, though efgartigimod demonstrated a favorable safety and tolerability profile with no new safety signals identified.
The randomized, double-masked, placebo-controlled studies evaluated efgartigimod PH20 SC administered by prefilled syringe with the primary endpoint measuring percentage of proptosis responders at week 24.
argenx SE (search) announced the discontinuation of its Phase 3 UplighTED studies evaluating efgartigimod subcutaneous (SC) in adults with moderate to severe thyroid eye disease (search) (TED), following a recommendation from an Independent Data Monitoring Committee (IDMC) to stop the trials for futility. The decision came after the IDMC's review of data from a pre-specified interim analysis, though importantly, efgartigimod showed a favorable safety and tolerability profile with no new safety signals identified.
"We are disappointed the studies did not meet our desired outcome and we especially empathize with patients who are living with TED and seeking new therapies for this challenging disease," said Luc Truyen, M.D., Ph.D., Chief Medical Officer at argenx. "We had pre-planned this futility analysis as it provides a meaningful interim evaluation of observed patient outcomes and enables us to responsibly evaluate the study's future likelihood of success."
Study Design and Methodology
The Phase 3 randomized, double-masked, placebo-controlled, multicenter studies were designed to evaluate the efficacy, safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of efgartigimod PH20 SC administered by prefilled syringe in adult participants with thyroid eye disease (search). Enrolled participants had active, moderate-to-severe thyroid eye disease associated with autoimmune thyroid conditions, specifically Graves' disease (search) or Hashimoto's thyroiditis (search).
Patients were randomized in a 2:1 ratio to receive efgartigimod PH20 SC or placebo PH20 SC during the double-blinded treatment period. The primary endpoint measured the percentage of participants who were proptosis responders at week 24. Key secondary endpoints included change in proptosis measurement in the study eye from baseline up to week 24, change in the total Graves' Orbitopathy Quality of Life (GO-QoL) score from baseline up to week 24, and percentage of participants with resolution of diplopia at week 24.
Clinical Context and Disease Background
Thyroid Eye Disease (search) is an autoimmune orbital disease associated with Graves' disease (search) and other autoimmune thyroid pathologies such as Hashimoto's thyroiditis (search). TED is characterized by extraocular muscle enlargement, orbital adipose tissue expansion, and orbital inflammation, which can lead to proptosis, diplopia, or vision loss in severe cases. Persistent orbital symptoms often impair patient quality of life.
In the active phase, swelling and protrusion can cause pain and may affect vision. In the inactive phase, some symptoms may improve; however, protrusion and double vision may persist, highlighting the significant unmet medical need in this patient population.
Drug Mechanism and Development
VYVGART (efgartigimod alfa fcab) is a human IgG1 antibody fragment that binds to the neonatal Fc receptor (search) (FcRn (search)), resulting in the reduction of circulating IgG autoantibodies. It represents the first approved FcRn blocker for the treatment of generalized myasthenia gravis (search) (gMG) and chronic inflammatory demyelinating polyneuropathy (search) (CIDP) globally, and for primary immune thrombocytopenia (search) (ITP) in Japan.
VYVGART SC (search) is a subcutaneous combination of efgartigimod alfa and recombinant human hyaluronidase PH20 (rHuPH20), utilizing Halozyme's ENHANZE drug delivery technology to facilitate subcutaneous injection delivery of biologics. The formulation is marketed under different names across regions: VYVGART Hytrulo in the U.S., VYVGART SC in Europe, and VYVDURA in Japan.
Future Analysis and Data Sharing
The IDMC conducted a futility evaluation of unblinded data from patients completing 24 weeks in the Phase 3 studies. Following close out and database lock, argenx will conduct a comprehensive analysis of the data to enhance understanding of the studies' outcomes and uncover key biological insights that may inform future research in TED. The company plans to share data from the studies at a future medical meeting.
This disciplined approach reflects argenx's commitment to responsible stewardship of investment and resources in clinical development programs, while the company continues to advance its broader portfolio of novel antibody-based medicines for severe autoimmune diseases.