Ganciclovir ophthalmic gel 0.15%: safety and efficacy of a new treatment for herpes simplex keratitis.

Background: Until the availability of ganciclovir ophthalmic gel in 2009, the only option for treating herpes simplex (HSV) keratitis in the USA has been trifluridine (TFT), a compound with tolerability issues related to its nonselective inhibition of DNA replication in both normal cells and virus-infected cells. Ganciclovir has selective pharmacologic activity on viral thymidine kinase and a lower potential for toxicity to healthy human cells. Our objective was to evaluate safety and efficacy findings reported with the use of ganciclovir ophthalmic gel, both for HSV keratitis and other potential clinical indications.

Methods: Clinical and preclinical data with ganciclovir were identified through a comprehensive electronic search of PubMed and Medline, using the search terms ganciclovir, ganciclovir 0.15% ophthalmic gel, acyclovir, acyclovir ointment 3%, herpes simplex keratitis, treatment of herpes simplex keratitis, and adenoviral keratoconjunctivitis. The authors were also granted access to previously unpublished ganciclovir surveillance safety data from Bausch & Lomb, Inc.

Results: No clinical data comparing ganciclovir ophthalmic gel to 1% trifluorothymidine (TFT) for HSV keratitis could be identified. Four international, randomized, multicenter clinical trials have demonstrated that ganciclovir gel is at least as effective as acyclovir ointment for the treatment of HSV keratitis. Ganciclovir gel was better tolerated, with lower rates of blurred vision, eye irritation, and punctate keratitis. Recent data also indicate it may hold promise as a treatment for adenoviral keratoconjunctivitis. Worldwide safety surveillance data collected over the past 10-15 years in over 30 countries suggests an extremely low rate of spontaneously reported adverse events with ganciclovir ophthalmic gel.

Conclusions: Current data suggest that ganciclovir ophthalmic gel has similar efficacy as acyclovir ointment for the treatment of HSV keratitis and is better tolerated. Clinical head-to-head studies comparing ganciclovir and TFT would be of great interest, especially for US physicians.