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Phase 3 Data Demonstrate Single Intravitreous Injection of Vitrase Results in Improved Visual Acuity
The subset analysis considered results in patients suffering from severely decreased visual acuity associated with non-clearing vitreous hemorrhage (VH) not due to age-related macular degeneration (AMD). According to the analysis, a single intravitreous injection of 55 IU Vitrase resulted in statistically greater improvement in best-corrected visual acuity (BCVA) of three or more lines on an eye chart when compared to a single injection of saline solution (p = .002).
"The wealth of positive Phase III data on our thimerosal-free Vitrase to manage vitreous hemorrhage, a serious and severely debilitating eye ailment, is further reinforced by this subset analysis of patients with non-clearing VH not due to AMD," stated Lisa R. Grillone, Ph.D., Vice President of Clinical Research and Medical Affairs at ISTA Pharmaceuticals. "We believe that the results from our clinical trials for Vitrase demonstrate the potential clinical usefulness of this drug, particularly in patients without AMD."
About the Clinical Trials
A total of 1,306 patients were enrolled in two randomized, double-masked, placebo-controlled international studies. The 750 patients enrolled in the North American study were assigned to one of four treatment arms (saline injection, 7.5 IU, 55 IU or 75 IU Vitrase injection), while the 556 patients treated in the second study outside North America were assigned to one of three treatment arms (saline injection, 55 IU or 75 IU Vitrase injection). In both studies, patients with a vitreous hemorrhage for at least one month were enrolled if their hemorrhage was designated as severe and their best-corrected visual acuity in the study eye was worse than 20/200 at the time of entry into the study. Treatment success for the primary (surrogate) endpoint in both studies was defined as the clearance of vitreous hemorrhage sufficient to allow the diagnosis and appropriate treatment, if needed, of the underlying cause of the vitreous hemorrhage within three months following treatment. Additionally, at each study visit and specifically at months one, two and three following treatment, BCVA was assessed using an eye chart.
ISTA's Vitrase(R) is a proprietary formulation of highly purified ovine hyaluronidase. In May 2004, the FDA approved Vitrase(R) in a lyophilized 6200 USP Units multi-purpose vial for use as a spreading agent; a 200 USP Units/mL vial in sterile solution for use as a spreading agent was approved in December 2004. FDA's approval of Vitrase for use as a spreading agent in May 2004 removed hyaluronidase from the FDA's drug shortage list where it had been listed since 2001.
In addition to its approval for use as a spreading agent, for hypodermoclysis and as an adjunct in subcutaneous urography, Vitrase(R) has been studied for the treatment of vitreous hemorrhage. A New Drug Application, or NDA, was filed for the treatment of vitreous hemorrhage in 2002 and an approvable letter for that NDA was received in 2003. In the letter, the FDA cited issues primarily related to the sufficiency of the efficacy data submitted with the NDA. The FDA requested additional analysis of the existing data and an additional confirmatory clinical study based upon that analysis. Vitrase (R) has also been studied for the treatment of diabetic retinopathy.
Source: ISTA Pharmaceuticals, Inc.