ISTA Pharmaceuticals Announces Preliminary Results of T-Pred Studies

IRVINE, Calif., Sept. 8 /PRNewswire-FirstCall/ -- ISTA Pharmaceuticals, Inc. (Nasdaq: ISTA), today announced preliminary results from two recently completed studies on its investigational ophthalmic product, T-Pred(TM) (prednisolone acetate 1.0% and tobramycin 0.3% ophthalmic suspension). The Company is developing T-Pred as a treatment for inflammatory ocular conditions for which a corticosteroid is indicated and where bacterial ocular infection exists, or there is a risk of bacterial infection.

In the first study, ISTA evaluated the antimicrobial equivalence between T-Pred and a tobramycin-containing reference product. In vitro tests were conducted to compare the kill rate of T-Pred with the kill rate of the reference product for each of the micro-organisms listed in the reference product's package insert as well as additional micro-organisms specified by the Food and Drug Administration (FDA). ISTA successfully demonstrated the antimicrobial bioequivalence of T-Pred to the reference product in each of the 26 required tests.

The second study was a Phase 3 clinical study designed to determine the bioequivalence of prednisolone concentrations between T-Pred and a reference product containing prednisolone acetate 1.0%. The multi-center, randomized, double-masked study enrolled 172 patients undergoing bilateral cataract removal. Patients served as their own internal control in this study, receiving one drop of either T-Pred or the prednisolone reference product prior to cataract extraction. Aqueous humor sampling was performed at one of four assigned time points. In order to demonstrate the bioequivalence of the two products, the ratio of calculated prednisolone values in aqueous humor needed to fall between 80% and 125%, with a 90% confidence interval for the ratios during all time points measured. Although T-Pred's prednisolone concentrations in this study were similar to those of the reference product, bioequivalence was not demonstrated. ISTA believes differences in the prednisolone reference product, which included a higher drug concentration in the formulation and a recent change in the reference product commercial product delivery dose, may have contributed to the variations in study results between the two products.

ISTA is discussing the study results with the FDA to determine the best path forward for T-Pred. The Company is working with the FDA to determine the appropriate clinical study or studies to perform in lieu of an additional prednisolone bioequivalence study, although no further clinical studies are planned before 2010.

About ISTA Pharmaceuticals
ISTA Pharmaceuticals is the fourth largest branded ophthalmic pharmaceutical business in the U.S. ISTA's three marketed products plus its product candidates include therapies for inflammation, ocular pain, glaucoma, allergy, and dry eye. The Company is developing a strong product pipeline to fuel future growth and market share, thereby continuing its growth to become the leading niche ophthalmic pharmaceutical company in the U.S. For additional information regarding ISTA, please visit ISTA Pharmaceuticals' website at http://www.istavision.com.

Any statements contained in this press release that refer to future events or other non-historical matters are forward-looking statements. Without limiting the foregoing, but by way of example, statements contained in this press release related to the outcome of ISTA's current or future discussions with the FDA and the potential initiation of further T-Pred clinical studies in 2010 are forward-looking statements. Except as required by law, ISTA disclaims any intent or obligation to update any forward-looking statements. These forward-looking statements are based on ISTA's expectations as of the date of this press release and are subject to risks and uncertainties that could cause actual results to differ materially. Important factors that could cause actual results to differ from current expectations include, among others, uncertainties and risks regarding market acceptance of and demand for ISTA's approved products; delays and uncertainties related to the FDA or other regulatory agency approval or actions; and such other risks and uncertainties as detailed from time to time in ISTA's public filings with the U.S. Securities and Exchange Commission, including but not limited to ISTA's Annual Report on Form 10-K for the year ended December 31, 2008, and its most recent Quarterly Report on Form 10-Q for the quarter ended June 30, 2009.

SOURCE ISTA Pharmaceuticals, Inc.

Vince Anido, Ph.D., +1-949-788-5311, vanido@istavision.com;
or Lauren Silvernail, +1-949-788-5302, lsilvernail@istavision.com,
both of ISTA Pharmaceuticals;
or Investors:
Juliane Snowden, +1-212-213-0006, jsnowden@burnsmc.com,
or Media:
Justin Jackson, jjackson@burnsmc.com,
both of Burns McClellan, +1-212-213-0006, for ISTA Pharmaceuticals