Avedro Inc. has received a complete response letter from the U.S. Food and Drug Administration (FDA) regarding its new drug application (NDA) for riboflavin ophthalmic solution/KXL System to treat keratoconus and corneal ectasia after refractive surgery.
"In the complete response letter, the agency identified a number of areas of the application which require additional information," the company recently announced.
"While we do not yet have an estimate on how long it will take to resolve the issues, we are confident that we can adequately answer their questions," says Avedro Chief Executive Officer David Muller, PhD.
The FDA granted orphan drug status to riboflavin ophthalmic solution/KXL System for treatment of keratoconus and corneal ectasia after refractive surgery in 2011.
"Patients with these sight-threatening conditions may require corneal transplant surgery. If approved, the riboflavin ophthalmic solution/KXL System would be the first FDA-approved therapeutic treatment for these orphan indications," the company said.
The treatment works by strengthening the cross-links between fibrils that serve as "natural anchors" within the cornea.
The KXL system is approved outside the United States, where 75,000 surgeries have been performed successfully, according to the company.
Avedro received priority review status on the NDA in November 2013.