A refillable chamber can deliver effective levels of anti-VEGF while reducing the need for office visits currently experienced under conventional intravitreal injection protocols, a study found.

This morning at the annual meeting of the American Academy of Ophthalmology, Carl Regillo, MD, of Philadelphia’s Wills Eye Hospital presented Phase II data from the LADDER trial of the Port Delivery System (PDS), an intravitreal drug reservoir implant currently being developed by Genentech. The PDS delivers a concentrated version of ranibizumab released into the vitreous over an extended time period.

The four-arm study compared three concentrations of ranibizumab delivered via PDS and monthly injections of Lucentis delivered by intravitreal injection to treat wet AMD. The primary endpoint was time elapsed until the need for PDS refill. Patients treated with the highest dose (100mg/mL) using PDS delivery had the greatest success: median duration to first needed refill was 15 months, and 80% of those patients required no refill within the first six months.

Visual actual gains from PDS delivery were comparable to or better than those of injection. At nine months, the high-dose PDS arm elicited a gain of 5.0 letters on ETDRS acuity vs. 3.9 letters for Lucentis injection. Final acuity in each of these two arms was 20/32.

A Phase III study called Archway, which uses a fixed 24-week interval dosing regimen, began enrolling last month.