Santen Pharmaceutical Co. Ltd. and Tracon Pharmaceuticals Inc. are discontinuing development of eye drug DE-122 after it failed to improve vision in a mid-stage trial.

DE-122 was being evaluated in the phase 2a trial, called Avante, in combination with Roche Holding AG's Lucentis for treating wet age-related macular degeneration — a disease in which abnormal blood vessels grow underneath the retina causing blurred vision and rapid and severe vision loss.

The companies said DE-122, when combined with Lucentis, did not meet the trial's main goal of improving visual acuity in patients with wet AMD compared to those taking Lucentis alone.

Osaka, Japan-based Santen licensed the development rights to DE-122 from San Diego-based Tracon in 2014.

The move is not expected to impact Santen's financial results for the fiscal year ending March 31.