FRI546 VRDN-001, A Full Antagonist Antibody To IGF-1 Receptor In Development For Thyroid Eye Disease (TED): Pharmacodynamic Responses In Healthy Volunteers And Patients With Active TED

Abstract Disclosure: K. Foster: Employee; Self; Viridian Therapeutics Inc. B.A. Dickinson: Employee; Self; Viridian Therapeutics Inc. R.M. Summerfelt: Employee; Self; Viridian Therapeutics Inc. A. She: Employee; Self; Viridian Therapeutics Inc. V. Bedian: Employee; Self; Viridian Therapeutics Inc. B. Katz: Employee; Self; Viridian Therapeutics Inc. Introduction: VRDN-001, a full antagonist antibody to IGF-1 receptor (IGF-1R), is in development for the treatment of thyroid eye disease (TED). Clinical and preclinical evidence demonstrate IGF-1R antagonism reduces the inflammation and proptosis that occur in TED. We provide pharmacodynamic (PD) results in healthy volunteers and TED patients from our ongoing phase 1/2/3 clinical trial (NCT05176639) evaluating VRDN-001. Methods: Healthy volunteers (HVs) and patients with active, moderate-to-severe TED were randomized 3:1 to receive 2 intravenous infusions 3 weeks apart (i.e., at week 0 and week 3) of either VRDN-001 (at 3-20 mg/kg) or placebo. PD parameters (IGF-1 serum levels) were assessed through 7 weeks. Results: Thirteen HVs received either placebo (n=3) or VRDN-001, 3 mg/kg (n=3), 10 mg/kg (n=3), or 20 mg/kg (n=4). Additionally, 16 TED patients received either placebo (n=4), 10 mg/kg of VRDN-001 (n=6), or 20 mg/kg of VRDN-001 (n=6). Baseline characteristics were similar across all TED cohorts. All VRDN-001 doses (3-20 mg/kg) elicited rapid, sustained, and similar increases in IGF-1 serum levels, a biomarker for target engagement and IGF-1R inhibition. In HVs receiving VRDN-001 (n=10), IGF-1 serum levels increased within a day of the first infusion for all doses, reaching 4-6-fold above baseline; levels continued to increase after the second infusion, ultimately reaching 4-9-fold above baseline. In TED patients receiving VRDN-001 (n=12), IGF-1 serum levels increased for both doses 2-6-fold above baseline after the first infusion, and further increased after the second infusion, ultimately reaching levels 4-9-fold above baseline. No increases in IGF-1 serum levels occurred for placebo. Conclusions: Two infusions of VRDN-001 in healthy volunteers as well as TED patients elicited rapid and sustained increases in IGF-1 serum levels that were similar across groups, indicating maximal target engagement at all doses tested. Results from an additional ongoing cohort of 3 mg/kg in TED patients will further inform optimal VRDN-001 dosing and potential treatment regimens to balance efficacy and safety and minimize treatment burden in TED. Presentation: Friday, June 16, 2023