Systemic Interleukin 1β Inhibition in Proliferative Diabetic Retinopathy

PURPOSE To evaluate the effect of systemic interleukin 1β inhibition using canakinumab (Ilaris) on retinal neovascularizations in proliferative diabetic retinopathy. METHODS Patients with proliferative diabetic retinopathy were enrolled in a prospective uncontrolled pilot study. Canakinumab (150 mg) was given 3 times subcutaneously. The primary end point was the change in the area of neovascularization from baseline to Week 24. Secondary end points were the change in retinal edema measured and best-corrected visual acuity (BCVA), as well as systemic safety evaluation, HbA1c, and systemic inflammatory parameters. RESULTS Systemic canakinumab treatment was well tolerated. None of the 8 eyes showed progression of neovascularizations within 24 weeks. Their mean size remained unchanged comparing 0.60 mm at baseline with 0.62 mm at Week 24 (P = 0.944). Median BCVA remained stable with 80 ETDRS letters at baseline and 82 ETDRS letters at Week 24. A not statistically significant reduction in retinal edema was detectable for the foveal central subfield thickness (mean, 313-295 μm). Mean HbA1c improved significantly from 7.92% to 7.30% within the 24 weeks (P = 0.046). Systemic inflammatory parameters remained overall unchanged. CONCLUSION Systemic canakinumab showed no change in neovascularizations in diabetic retinopathy. Promising effects were seen on diabetic macular edema.