ISTA Pharmaceuticals Announces Positive Preliminary Results from Ecabet Sodium Phase IIb Study - Pending Final Analysis of the Results, ISTA Plans to Initiate Phase III Studies in Dry Eye in 2008 - IRVINE, Calif., May 31, 2007 -- ISTA Pharmaceuticals, Inc. , today announced positive results from the preliminary analysis of the Company's Phase IIb clinical study of ecabet sodium, which is being developed as a treatment for dry eye syndrome. Patients in the ecabet sodium group achieved a strong trend in the objective sign of blink rate. In addition, patients in the ecabet sodium group reported a strong trend in the Ocular Symptom Disease Index (OSDI) and a positive trend in the subjective assessment of patients' most bothersome symptom. Strong and positive trends are used to confirm observations from previous clinical ecabet sodium studies and to serve as indicators of potential efficacy endpoints in Phase III studies. While ISTA's Phase IIb study was not powered to show statistical significance, ecabet sodium did achieve statistical significance in the OSDI assessment. There were no reports of serious ocular adverse events compared with placebo. Further analyses of the Phase IIb study results are ongoing. "We are very encouraged by the Phase IIb study's preliminary results, as they support our belief that ecabet has the ability to treat signs and symptoms of dry eye syndrome," stated Vicente Anido, Jr., Ph.D., President and Chief Executive Officer of ISTA. "Our key objectives for this study were to validate our protocol and to screen out non-responders. We were successful in doing both. In addition, we showed positive trending in one sign and one symptom, plus achieved statistical significance in a second symptom, all in a single study. Ecabet sodium may provide advantages over other dry eye products and product candidates, as we believe the drug not only improves the quality of tears by enhancing mucin production, but may increase the quantity of tears produced. Although not a predetermined endpoint in this study, 14 percent of patients in the treatment group reported increases in the quantity of tears produced, as compared to only 1.8 percent in the placebo group. We are continuing our analyses of both of our Phase II clinical studies to identify the signs and symptoms to evaluate in Phase III testing. Upon completion of the analyses, we will request a meeting with the Food and Drug Administration to discuss its recommended clinical path in order to bring this novel treatment to patients suffering from dry eye syndrome. At this time, we anticipate beginning Phase III studies in 2008." A total of 112 patients were assigned randomly to receive either ecabet sodium or placebo four times a day for 90 days. There were four primary efficacy endpoints: two objective signs (blink rate and corneal staining) and two subjective symptoms (the patient's most bothersome symptom and the patient's response to the Ocular Surface Disease Index (OSDI)). Patients were evaluated in a controlled adverse environment ("dry eye chamber") twice during the study, once on Day 1 and once on Day 91. The objective signs were measured pre- and post-exposure to the dry eye chamber on Day 91. The subjective symptoms were measured following exposure to the dry eye chamber on both Day 1 and Day 91. To date, the FDA has considered improvement, as measured in Phase III studies, in one sign and one symptom to be acceptable for approval of a prescription dry eye product. ISTA will host a conference call with a simultaneous webcast tomorrow, Friday, June 1, 2007, at 11:00 AM Eastern Time to discuss today's announcement regarding the ecabet sodium Phase IIb study preliminary results and other recent product and commercial developments. To access the live conference call, U.S. and Canadian participants may dial 866-356-4281; international participants may dial 617-597-5395. The access code for the live call is 93323302. To access the 24-hour audio replay, U.S. and Canadian participants may dial 888-286-8010; international participants may dial 617-801-6888. The access code for the replay is 43054090. This conference call will also be webcast live and archived on ISTA's website for 30 days at http://www.istavision.com. About Ecabet Sodium ISTA acquired U.S. rights to ecabet sodium for the treatment of dry eye syndrome from Senju Pharmaceuticals Co., Ltd., in November of 2004. Ecabet sodium is already marketed in Japan as an oral agent for gastric ulcers and gastritis by Tanabe Seiyaku Co., Ltd as an originator of ecabet sodium. Ecabet sodium represents a new class of molecules that increase the quantity of mucin produced by conjunctival goblet cells and corneal epithelia. Mucin is a glycoprotein component of tear film that lubricates while retarding moisture loss from tear evaporation. About ISTA ISTA Pharmaceuticals is an ophthalmic pharmaceutical company. ISTA's products and product candidates addressing the $3.2 billion U.S. prescription ophthalmic industry include therapies for inflammation, ocular pain, glaucoma, allergy, dry eye, and vitreous hemorrhage. The Company currently markets three products and is developing a strong product pipeline to fuel future growth and market share. The Company's product development and commercialization strategy is to launch a new product every 12 to 18 months, 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. Statements contained in this press release that refer to future events or other non-historical matters are forward-looking statements. For example, and without limiting the foregoing, statements in this press release related to the prospects and timing of further development of ecabet sodium (including but not limited to statements that ISTA will complete its analysis and confirm its preliminary Phase IIb findings, meet with the FDA, and initiate a Phase III study with respect to ecabet sodium during 2008), the potential of ecabet sodium to treat dry eye syndrome and its potential advantages over other currently marketed dry eye products, ISTA's statements about potential future objective endpoints for Phase III studies and ISTA's goals of bringing a new product to market every 12 to 18 months and becoming the leading niche ophthalmic pharmaceutical company in the U.S. are forward-looking statements. Except as required by law, ISTA disclaims any intent or obligation to update any forward-looking statements. Such 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: the risk that full analysis of the Phase IIb data or further testing of ecabet sodium, will not reflect the preliminary Phase IIb results, or support any or all of the conclusions provided in this press release; delays, risks and uncertainties related to ISTA's ecabet sodium development program (including the difficulty of predicting the timing or outcome of ISTA's product development efforts and the FDA or other governmental agency approval or actions); uncertainties and risks regarding market acceptance of ISTA's approved products and the impact of competitive products and pricing; risks and uncertainties related to successful compliance with FDA and/or other governmental regulations applicable to ISTA's facilities, products, and/or business; uncertainties and risks related to the scope, validity, and enforceability of patents related to ISTA's products and technologies and the impact of patents and other intellectual property rights held by third parties, and such 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, 2006, and ISTA's Quarterly Report on Form 10-Q for the quarter ended March 31, 2007.