FDA OKs ophthalmic gel

The recent FDA approval of ganciclovir ophthalmic gel 0.15% (Zirgan, Sirion Therapeutics) for the treatment of acute herpetic keratitis brings to U.S. ophthalmologists an important advance in topical antiviral therapy for a condition that is the leading infectious cause of corneal blindness in the United States, said Herbert E. Kaufman, MD.

"Trifluridine has served us well as an effective treatment for ophthalmic herpes, but it is associated with significant toxicity because it is a nonspecific agent that affects DNA synthesis in both viral-infected and normal cells," Dr. Kaufman said. "As a result, trifluridine has the potential to interfere with the healing process, which has made me concerned about using it to treat large corneal ulcers, and it can also cause punctal occlusion, epiphora, scarring, and epithelial keratitis.

Sirion Therapeutics licensed the exclusive U.S. rights to develop and market ganciclovir 0.15% ophthalmic gel from Laboratoires Thea. FDA approval for marketing in the United States was granted based on the results of older premarketing clinical trials conducted by the French company in Europe, Asia, and Africa, combined with the efficacy and safety profile demonstrated by ganciclovir gel in more than a decade of postmarketing experience.

The premarketing studies included an open-label, randomized, controlled, multicenter clinical trial enrolling 164 patients that showed ganciclovir gel was noninferior to acyclovir 3% ointment for healing dendritic ulcers. After 7 days of treatment, rates of healed ulcers were 77% (55/71) in the ganciclovir group and 72% (48/67) for acyclovir.

Similar results were achieved in three randomized, single-masked multicenter trials that enrolled 213 patients. In those studies, ulcer healing rates at day 7 in the ganciclovir gel and acyclovir groups were 72% (41/57) versus 69% (34/49), respectively.