Purpose
Interleukin-6 (IL-6) and/or its soluble receptor are detected in the vitreous and aqueous humors of patients with uveitis. Inhibition of IL-6 signaling in a murine model of experimental autoimmune uveitis suppresses the development of uveitis. We designed an exploratory study to evaluate the efficacy and safety of sarilumab, a fully human monoclonal antibody directed against the alpha subunit of the IL-6 receptor complex in the management of posterior segment NIU.
Methods
SATURN is a 52 week multicenter, double-masked, placebo-controlled, parallel arm, randomized trial to evaluate the efficacy and safety of sarilumab (200 mg) administered subcutaneously every 2 weeks in patients with posterior NIU, who are treated with systemic steroids (as single therapy or with methotrexate). Efficacy and safety are assessed at each visit. The study primary endpoints are reduction from baseline in vitreous haze and systemic-steroid sparing effects, both measured at week 16. Other key endpoints assessed at week 16 include the change from baseline in: central retinal thickness, best-corrected visual acuity, and retinal vessel leakage on fluorescein angiography. A graphical representation of the study design is presented in the Figure below.
Results
The study is ongoing. As of 29 October 2014, 33 of 57 patients have been randomized and treated; 19 subjects have completed the Principal Treatment Period (Part A). Baseline demographic and disease characteristics are presented in the Table below.
Conclusions
The SATURN study may help clarify the role of IL-6 in the pathogenesis of NIU and the potential for IL-6 inhibition in the management of posterior segment NIU.