Anecortave acetate therapy shows potential for OAG

Fort Lauderdale, FL-Anecortave acetate (Retaane, Alcon Laboratories) is a potential new therapy for open-angle glaucoma (OAG) that seems to be highly effective, with a mean 25% decrease in IOP 6 months after one anterior juxtascleral injection, Alan L. Robin, MD, reported at the annual meeting of the Association for Research in Vision and Ophthalmology.

"This is potentially a very exciting new drug and new delivery system for medication in the treatment of glaucoma. Anecortave acetate is a steroid that lowers IOP," said Dr. Robin, associate professor of ophthalmology at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore.

He pointed out that in the past years with the injection of triamcinolone into the vitreous, researchers have become very attuned to the role of corticosteroids and how they create glaucoma.

While anecortave acetate is chemically similar to tetrahydrocortisol, modifications-such as the removal of the 11-hydroxyl group, introduction of the C9-11 double bond, and addition of a 21-acetate group-result in the absence of the anti-inflammatory and immunosuppressive properties of glucocorticoids, he said.

"It does not appear to raise IOP and does not appear to cause cataracts," Dr. Robin emphasized.

In a rabbit model, steroids and placebo were administered. Topical anecortave acetate was especially able to reduce IOP increase associated with the administration of steroids, he recounted.

In line with the efficacy of anecortave is the lack of compliance of patients being treated for glaucoma, especially in those patients who take multiple medications.

"The adherence, persistency, and compliance with a medication regimen decreases dramatically with the number of medications given and the more complex the regimen is," he said. "In addition, adding a second medication doesn't often achieve the desired effect."

The potential of a single injection that would markedly reduce IOP levels for prolonged periods seems to be the "Holy Grail" in the treatment of glaucoma.

Dr. Robin and colleagues conducted a nonrandomized, open-label pilot trial of anecortave acetate in six patients with primary open angle glaucoma who were all taking at least one IOP-lowering medication. The anterior sub-Tenon's injections were given over approximately 1 minute without any clinically significant adverse effects. The mean IOP before treatment was almost 31 mm Hg.

Dr. Robin demonstrated the ocular appearance of patients following the injection and how their appearances improved markedly within hours after the treatment. By day 7 and at month 3 after treatment, the drug is no longer clinically visible.

"Five of the six patients had an IOP decrease of 25% or greater 3 months after the injection," Dr. Robin said. "The mean IOP decrease after treatment was more than an additional 10 mm Hg. This was an impressive result, that is, a sustained IOP decrease with only one injection of anecortave acetate, considering these patients were already taking other medications."

In addition to the sustained decrease in IOP, Dr. Robin pointed out the delivery system may become an answer to administration of eye drops, which can be problematic in some patients because of lack of manual dexterity and poorer vision in an older population.

Studies are under way to determine the mechanism of action of anecortave acetate in the lowering of IOP, the duration of action of the drug, and the repeatability of the treatment. Dr. Robin speculated that the drug may remodel the trabecular meshwork. He also cautioned that the number of patients in this study is too small to draw any definitive conclusions.