** Shares of biotech firm Ocugen OCGN.O rise 4.2% to $2.19 premarket

** Co says its experimental gene therapy slowed disease progression in geographic atrophy, an advanced eye condition that causes vision loss in older people

** Mid-stage trial showed OCU410 cut growth of vision-damaging eye lesions by 31% over 12 months, co says

** Co compares result with about 15% reduction at 12 months and 22% at 24 months seen with approved treatments, which need frequent eye injections

** No serious side effects linked to the one-time treatment were reported, co says

** Says it plans larger late-stage trial later this year and aims to seek regulatory approval within three years

** Shares rose ~68% in 2025

(Reporting by Sahil Pandey in Bengaluru)

((Sahil.Pandey@thomsonreuters.com))