Opthea Ltd., of Melbourne, Australia, said it started a phase Ib/IIa trial testing OPT-302 in patients with center-involved diabetic macular edema (DME). The two-part design consists of a dose-escalation portion testing OPT-302 (0.3 mg, 1 mg and 2 mg) in combination with VEGF-A inhibitor Eylea (aflibercept, Regeneron Pharmaceuticals Inc.), followed by a phase IIa randomized, controlled dose expansion with treatment allocated in a 2-to-1 ratio to either OPT-302 with Eylea, or Eylea monotherapy.