Opthea (ASX:OPT) said its combination therapy candidate for diabetic macular edema showed potential in a first-in-human phase 1b study, according to a Tuesday filing with the Australian bourse.

The study tested the combination of sozinibercept and aflibercept in nine patients, with safety as the primary endpoint and mean change from baseline in best-corrected visual acuity as one of the secondary endpoints, the filing said.

Based on the results, the therapy was well tolerated, with no dose-limiting toxicities, the filing said. In addition, the 2 mg sozinibercept combination arm showed the highest best-corrected visual acuity gain.

Results from the study were published in the peer-reviewed journal Translational Vision Science & Technology, per the filing.

The company's shares rose past 5% in recent Tuesday trade.