Sirion Therapeutics, Inc. has announced that the US Food and Drug Administration (FDA) has approved its New Drug Application for Zirgan™ (ganciclovir ophthalmic gel) 0.15% as a treatment for acute herpetic keratitis. The FDA granted orphan drug designation to Zirgan for this indication in April 2007.

Outside of the United States, both ganciclovir gel and acyclovir ointment are standard-of-care therapies, and selectively target the replication of HSV DNA, unlike older antivirals which affect both healthy and infected cells.

In three randomized, single-masked, controlled, multicenter clinical trials which enrolled 213 patients, Zirgan was non-inferior to acyclovir in patients with dendritic ulcers. Clinical resolution at Day 7 was achieved in 72% of patients for Zirgan versus 69% for acyclovir. In one open-label, randomized, controlled, multicenter clinical trial which enrolled 164 patients with herpetic keratitis, Zirgan was non-inferior to acyclovir in patients with dendritic ulcers.

The recommended dosing regimen for Zirgan is 1 drop in the affected eye 5 times per day until the ulcer heals, and then 1 drop 3 times per day for 7 days. The company expects that the agent will be available in early 2010.

Read ^[1] the release.