* Treatment meets main goal of late-stage trial
* Co expects to file U.S. marketing application in Q4
* Shares surge 50 pct (Adds comments from analyst and conference call, background; updates share movement)
March 5 (Reuters) - Clearside Biomedical Inc said on Monday its experimental treatment helped improve vision in patients with fluid buildup in the eye in a late-stage study, compared with a placebo, sending its shares surging more than 50 percent.
The drug developer tested the treatment, suprachoroidal CLS-TA, in patients with macular edema associated with inflammation in the eye known as uveitis.
In the trial, 47 percent of patients being administered the company's treatment could see at least 15 letters, compared to 16 percent patients who underwent a placebo procedure.
"To my knowledge, this is the greatest proportional increase ever observed in a uveitis study," Rahul Khurana, an investigator for the trial said during the company's call with analysts.
Macular edema occurs in about one-third of all non-infectious uveitis cases and is a major contributor to vision loss in these patients, according to the company.
There are no approved treatments for this type of macular edema, the company said, with patients usually treated with steroids.
However, steroid treatments had limitations due to adverse events, Needham & Co analyst Serge Belenger said.
Analysts also expect the drug to compete with Allergan Plc's Ozurdex, which has been approved in the United States to treat uveitis.
Clearside, which expects to file a marketing application with U.S. regulators in the fourth quarter, said detailed results would be presented at an upcoming medical conference.
The treatment is expected to rake in peak sales of $150 million-$200 million, according to Needham analysts.
The company's shares were up 52.8 percent at $11.95 in early morning trading. (Reporting by Manas Mishra in Bengaluru; Editing by Arun Koyyur and Sriraj Kalluvila)