Two years after gaining U.S. rights to an ocular product already sold in Japan, ISTA Pharmaceuticals Inc. submitted the drug for FDA review.

The Irvine, Calif.-based company filed a new drug application for Xibrom (bromfenac sodium ophthalmic solution) 0.1 percent. Applied topically two times a day, the non-steroidal, anti-inflammatory solution initially is being developed to treat eye inflammation following cataract surgery.

"There are two or three areas where we feel we'll have significant advantages over the competition, which we define as not only the non-steroidal, anti-inflammatory drugs, but also the low- and mid-potency steroids as well," ISTA CEO Vicente Anido told BioWorld Today. "We have clearly showed that the product works twice a day, while all of the other competitors are four times a day. The potency certainly is there . . . and if you look at the adverse event profile, we actually had, for the most part, a lower incidence than placebo."

Two months ago, ISTA reported Phase III findings that revealed that a statistically significant proportion of Xibrom-treated patients achieved treatment success, defined as the complete absence of ocular inflammation, compared to placebo. The two U.S.-based studies showed that Xibrom was well tolerated with few ocular adverse events such as irritation, inflammation and photophobia.

The first trial, which involved 296 patients, showed that 62.6 percent of those treated with Xibrom cleared their ocular inflammation at 15 days, compared to 39.8 percent of placebo patients. The second, which involved 231 patients, showed that 65.8 percent of Xibrom-treated patients had clearing of their ocular inflammation, compared to 47.9 percent of those on placebo. (See BioWorld Today, March 10, 2004.)

If the data support eventual approval, ISTA is eyeing a market opportunity it plans to tap through its internal sales force.

"We think that the market for non-steroidals, as well as low- and mid-potency steroids, adds up to about $250 million," Anido said, listing competitive products such as Acular (ketorolac tromethamine, Allergan Inc.), Lotemax (loteprednol etabonate, Bausch & Lomb Pharmaceuticals Inc.) and generic versions of prednisolone acetate.

Senju Pharmaceuticals Co. Ltd., of Osaka, Japan, launched the compound in that country four years ago, and ISTA gained U.S. marketing rights in May 2002 through its acquisition of AcSentient Inc. The NDA primarily was based on data from the two trials, as well as supporting data from Senju, which controls all rights outside the U.S., though it only sells Xibrom in Japan.

Anido said the product also might be studied for use following other ocular surgeries, to control pain and for allergies. He added that pain data included in the NDA, which stemmed from findings related to a secondary endpoint in the Phase III studies, might be sufficient to warrant an adjunct approval on an initial label.

ISTA's purchase of Research Triangle Park, N.C.-based AcSentient also brought on board worldwide marketing rights to a compound for hyphema called Caprogel, another product licensed from Senju. It has reached Phase III development, though Anido said ISTA is focused on reformulating the product before moving it back into clinical studies.

More recently, the company received FDA approval for Vitrase for use as a spreading agent to facilitate the dispersion and absorption of other drugs. The product is partnered with Allergan Inc., also of Irvine, and the companies are waiting on a regulatory decision on an earlier NDA for Vitrase as a single injection to the eye for vitreous hemorrhage. Last year, the FDA issued an approvable letter related to the submission, which asked for further data analysis with the possibility of a confirmatory study. (See BioWorld Today, April 8, 2003.)

ISTA also is awaiting a decision on a glaucoma product called Istalol, a once-daily, liquid formulation of the beta-blocker timolol also developed by Senju. Anido said the company expects approval this quarter following its resolution of manufacturing site issues that resulted in an approvable letter from the FDA last summer. (See BioWorld Today, July 29, 2003.)

On Tuesday, ISTA's stock (NASDAQ:ISTA) dropped 24 cents to close at $14.08.