Avedro has started patient enrolment in the ACP-KXL-308 trial, a pivotal Phase lll clinical study to examine the safety and efficacy of an epithelium-on (epi-on) corneal collagen cross-linking (CXL) procedure to treat patients with progressive keratoconus.

The multicentre, randomised, controlled trial intends to enrol 275 patients with progressive keratoconus across approximately 20 sites in the US, including Massachusetts, Ohio, Utah, Pennsylvania and Virginia.

Under the trial, patients will be randomised in a 2:1 ratio to provide CXL treatment or sham/control treatment.

The trial’s primary efficacy objective is a difference of one diopter between treatment groups in the mean change in Kmax from baseline to month six.

Its secondary objective is change from baseline in Kmax between treatment groups.

“Since the 2016 FDA approval of Avedro’s epi-off cross-linking treatment, thousands of patients with progressive keratoconus, a potentially debilitating disease, have benefitted from this procedure.”

Expected to be completed by June 2020, the ACP-KXL-308 trial aims to support an application for the US Food and Drug Administration (FDA) approval for epi-on CXL procedure with new drug formulation and use of oxygen.

Avedro chief medical officer Rajesh Rajpal said: “Since the 2016 FDA approval of Avedro’s epi-off cross-linking treatment, thousands of patients with progressive keratoconus, a potentially debilitating disease, have benefitted from this procedure.”

Keratoconus is a non-inflammatory eye condition where the typically round dome-shaped cornea progressively thins and weakens.

It is reported to be the major cause of penetrating keratoplasty (corneal transplant) in the US.