Secukinumab in Moderate-to-Severe Graves Orbitopathy: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Study

Clinical Snapshot

Key Findings

• P Value: Not reported

• Effect Size: No treatment effect observed

• Primary Outcome: Overall response (CAS reduction ≥2 points plus proptosis reduction ≥2mm): 0% in both groups

• Nnt Or Sensitivity: Not applicable - no treatment benefit demonstrated

• Confidence Interval: Not reported

Clinical Application

Limited by high cost of secukinumab and lack of demonstrated efficacy Results suggest secukinumab should not be considered for PBS listing for GO indication. Current RACGP and endocrinology society guidelines emphasize corticosteroids and selenium as first-line treatments, with this study supporting continued reliance on established therapies Adults with active, moderate-to-severe Graves orbitopathy not responding to conventional therapy

Abstract

CONTEXT: Interleukin (IL)-17, a key proinflammatory cytokine, drives inflammation and fibrosis in Graves orbitopathy (GO), and elevated IL-17 and Th17 cells correlate with disease activity and severity. OBJECTIVE: The ORBIT study aimed to evaluate the efficacy and safety of secukinumab, an IL-17A inhibitor, in individuals with active, moderate-to-severe GO. METHODS: A randomized, double-blind, placebo-controlled, parallel-group, multicenter trial was conducted. Adults with active, moderate-to-severe, non-sight-threatening GO randomly (1:1) received secukinumab 300 mg or placebo subcutaneously over a 16-week double-blind treatment period, followed by an additional 16-week open-label treatment phase for proptosis nonresponders. Safety parameters, thyroid-related hormones, and autoantibodies were also assessed. The primary end point was overall response of reduced Clinical Activity Score (CAS) of 2 or more points and a reduction of 2 mm or greater in proptosis from baseline without worsening in the fellow eye at week 16. RESULTS: Twenty-eight adult GO patients with a CAS of 4 or greater were enrolled (secukinumab, n = 14; placebo, n = 14). None in either the secukinumab or placebo group achieved an overall response at weeks 16 and 32, respectively, when all patients received open-label secukinumab. No clinically meaningful changes were observed in ophthalmic symptoms and signs, proptosis, lid aperture, eye muscle motility, CAS, and health-related quality of life either at week 16 or week 32. No meaningful effect on serum levels of thyroid-related hormones and antibodies was observed. Secukinumab was well tolerated, with mostly mild adverse events. Neither treatment-induced study discontinuation nor new safety signals were registered. CONCLUSION: Secukinumab did not show clinical efficacy vs placebo when treating patients with active, moderate-to-severe GO.

References

1. 1.Wolf, J., Lorenz, K., Othman, A. E., Beck, A., Michel, H. M., Grauhan, L., Elflein, H., Luffy, M., Eckstein, A., Lahner, H., Schittkowski, M., Horn, M., Lagrèze, W. A., Bleul, T., Pitz, S., Vorländer, C., Pieterse, C. C., Porter, B., Clemens, A., Draikiwicz, S., Reinhardt, M., & Kahaly, G. J. (2026). Secukinumab in moderate-to-severe Graves orbitopathy: A randomized, double-blind, placebo-controlled, multicenter study. *The Journal of Clinical Endocrinology and Metabolism*. https://doi.org/10.5281/zenodo.17550060