New "pink eye" treatment offers more convenience

June 4, 2007

The FDA approved a new treatment to help cure bacterial conjunctivitis, or pink eye, with the approval of azithromycin ophthalmic solution 1% (AzaSite) from Inspire Pharmaceuticals.

Terrence P. O'Brien, M.D., professor of ophthalmology at the University of Miami's Bascom Palmer Eye Institute, said the new formulation has a convenient topical dosing regimen requiring less than half the number of drops for effective treatment than the currently available products. In fact, according to Inspire, one drop should be instilled into the affected eye twice daily, eight to 12 hours apart for the first two days, followed by one drop once daily for the next five days, for a total of nine drops for the course of treatment.

Both in vitro and clinically, azithromycin has been shown to be effective for treating conjunctival infections caused by susceptible isolates of CDC Coryneform group G, Staphylococcus aurous, Streptococcus mitis group, and Streptococcus pneumoniae. Efficacy of the eyedrops was proven in two phase III clinical studies involving more than 750 subjects with confirmed bacterial conjunctivitis. It met both the primary and secondary efficacy endpoints of clinical resolution and bacterial eradication, respectively. Clinical resolution was defined as the absence of palpebral conjunctival injection, bulbar conjunctival injection, and ocular discharge. When compared with tobramycin ophthalmic solution, AzaSite was found to be statistically equivalent in both the primary and secondary efficacy endpoints.

As with other antibiotics, improved patient compliance could mean a lower incidence of developing bacterial resistance; however, the prescribing information warns that prolonged use of AzaSite could result in overgrowth of nonsusceptible organisms, including fungi.

Inspire Pharmaceuticals acquired exclusive rights to AzaSite from InSite Vision in February 2007. The product, which has patent coverage until 2019, is expected to generate $30 to $45 million in sales in 2008, according to the company.

TIPS TO REMEMBER AzaSite ophthalmic solution 1%