Iontophoresis: A new focus

San Francisco-A recent phase II study with a novel non-invasive iontophoretic drug delivery system (EyeGate II Delivery System, EyeGate Pharma) shows that the device appears to optimize the delivery of a proprietary dexamethasone-derived corticosteroid solution (EGP-437) and improve significantly the signs and symptoms of dry eye, which may raise the bar in therapies for dry eye syndrome, according to Gail L. Torkildsen, MD, who reported the study at the annual meeting of the American Academy of Ophthalmology.

Currently, ophthalmologists use several approaches to treat the signs and symptoms of dry eye, including various medications and modes of drug delivery. Optimizing drug regimens and the way treatments are delivered to the eye are key factors in the successful therapy of dry eye syndrome. Recent research shows that ocular iontophoresis may be one technology that can deliver a drug more effectively to target tissues, resulting in a quicker and more effective therapy.

Preliminary study results

In the 105-patient, randomized, single-center, double-masked, placebo-controlled study, 41 patients received a low dose of EGP-437 (7.5 mA-min at 2.5 mA), 38 patients received a high dose of EGP-437 (10.5 mA-min at 3.5 mA) and 26 patients received 100 mM sodium citrate buffer solution placebo (10.5 mA-min at 3.5 mA). The study utilized the Controlled Adverse Environmental (CAE) system on visits 1, 3, and 5, which exacerbated the signs and symptoms of dry eye in a controlled, standardized manner. Visits 2, 4, and 6 occurred 24 hours after visits 1, 3, and 5, respectively. Iontophoresis treatments with EGP-437 or placebo were administered 1 hour after and 1 hour before the CAE at visits 3 and 5, respectively.

Results showed that compared with placebo, EGP-437 could improve significantly the moderate to severe signs and symptoms of dry eye syndrome. Patients who received either the low or high dose of EGP-437 demonstrated significant improvements in their dry eye signs and symptoms (compared with placebo) in CAE challenge and CAE recovery, as well as environmental conditions. Results also showed that patients reported a significant decrease in ocular discomfort during the CAE at visit 5 after receiving only two doses of EGP-437.

"The results of the study suggest that EGP-437 may have a rapid onset of action and a long-lasting effect relative to placebo," said Dr. Torkildsen, of Andover Eye Associates, Andover, MA, the principal investigator in the study conducted by Ora Inc. "The positive results seen are likely due to the combination of dexamethasone delivered via the novel . . . system.

"Dexamethasone is a potent corticosteroid, but the EyeGate II system is the key to delivering the therapeutic exposures necessary to achieve the clinical results experienced," she added.

Adverse events seen in study participants included transient or reversible incidences of ocular hyperemia, keratitis, ocular discomfort, and conjunctival edema.