* Lower dose improved vision in 33.6 pct of patients
* Higher dose effective in 45.7 pct, placebo in 12.3 pct
LOS ANGELES, March 25 (Reuters) - A second late-stage trial of Roche Holding's ROG.VX Lucentis has shown that the drug improves vision in diabetics suffering from a complication that can cause blindness, according to the Swiss company's Genentech unit.
A Phase 3 study in patients with diabetic macular edema found that after 24 months, 33.6 percent of patients given a monthly injection of 0.3 mg of the drug were able to read at least 15 more letters on an eye chart.
That compared with 45.7 percent of patients given 0.5 mg injections of of Lucentis and 12.3 percent of patients given a sham injection.
Genentech said in a statement on Friday that the safety results of the trial were consistent with previous studies. The most common adverse events included conjunctival hemorrhage, eye pain and eye irritation.
People with diabetes frequently develop diabetic macular edema -- an accumulation of fluid and swelling within the macula, or the central part of the retina, that can lead to blindness.
Lucentis, discovered by Roche's U.S. biotech unit Genentech, was first approved by U.S. regulators in 2006 for the treatment of wet age-related macular degeneration.
The drug is designed to block a protein believed to play a critical role in the formation of new blood vessels. (Reporting by Deena Beasley, editing by Matthew Lewis)