Ganciclovir ophthalmic gel 0.15% approved by FDA for herpetic keratitis

Tampa, FL-Sirion Therapeutics Inc. announced the FDA approval of its new drug application for ganciclovir ophthalmic gel 0.15% (Zirgan) as a treatment for acute herpetic keratitis. The FDA granted orphan drug designation to the gel for this indication in April 2007.

Herpetic keratitis is a significant cause of corneal blindness and a leading indication for corneal transplantation in the United States, with approximately 50,000 new and recurrent cases each year, according to a prepared statement.

The FDA approval was based on the results of clinical trials conducted by Laboratoires Thea of France in Europe, Asia, and Africa that compared the efficacy and tolerability of ganciclovir ophthalmic gel 0.15% with acyclovir ophthalmic ointment 3% in patients with herpetic keratitis. Both ganciclovir gel and acyclovir ointment are standard-of-care therapies outside of the United States, and selectively target the replication of HSV DNA, unlike older antivirals, which affect both healthy and infected cells, according to a prepared statement.

In one open-label, randomized, controlled, multicenter clinical trial, which enrolled 164 patients with herpetic keratitis, ganciclovir was noninferior to acyclovir in patients with dendritic ulcers. Clinical resolution at day 7 was achieved in 77% (55/71) for ganciclovir versus 72% (48/67) for acyclovir.

In three randomized, single-masked, controlled, multicenter clinical trials, which enrolled 213 patients, ganciclovir was noninferior to acyclovir in patients with dendritic ulcers. Clinical resolution at day 7 was achieved in 72% (41/57) for ganciclovir versus 69% (34/49) for acyclovir.

"The approval of [ganciclovir] represents a true advance in topical antiviral therapies in the [United States]," said Barry Butler, chief executive officer of Sirion. "Up to this point, no therapy targeting only viral-infected cells was available for topical ocular use. [Ganciclovir] provides doctors with a much-needed modern treatment for herpetic keratitis."

The recommended dosing regimen for ganciclovir 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. Trifluridine ophthalmic solution is dosed at 1 drop every 2 hours while awake for a maximum of 9 drops daily until the ulcer heals. Ganciclovir will be supplied in a 5-g tube and will be available by prescription through retail pharmacies.

"We anticipate [ganciclovir] will be commercially available to U.S. physicians in early 2010," said Susan Benton, senior vice president of sales and marketing for Sirion. "We're pleased to introduce this important treatment option for herpetic keratitis to the [United States], especially since it has been the standard of care in Europe for over 10 years. We believe it will provide patients and physicians with an effective, safe, and convenient treatment for herpetic keratitis."