The MERITAGE Study, sponsored by NeoVista, is the first to evaluate the effect of epimacular brachytherapy in this population of patients. Epimacular brachytherapy takes a triad approach to treating neovascular AMD, Pravin U. Dugel, MD, explained.
"The crux of epimacular brachytherapy is a synergistic triad of increased oxygenation resulting from vitrectomy, targeted brachytherapy, and anti-VEGF injections," Dr. Dugel said.
The goal of the study was to determine if the treatment burden associated with intravitreal injections of an anti-VEGF drug could be decreased with the addition of epimacular brachytherapy and if the visual acuity (VA) level could be maintained. To date, more than 600 procedures have been performed in various trials.
"These patients were doing poorly and losing vision despite the increasing frequency of anti-VEGF drug injections," Dr. Dugel emphasized. The patients in the MERITAGE Study had minimally classic and occult lesions that were 35% larger compared with the patients in the MARINA Study who were treated with ranibizumab (Lucentis, Genentech, Inc.) and predominantly classic lesions that were 170% larger compared with the patients in the ANCHOR Study. Dr. Dugel is managing partner, Retinal Consultants of Arizona, Phoenix, AZ and clinical associate professor of ophthalmology, Doheny Eye Institute, Los Angeles.
An important component of the MERITAGE Study was two pre-enrollment phases designed to be certain that the full effect of the anti-VEGF therapy was realized. The first was a loading phase of three consecutive anti-VEGF injections and, the second, a maintenance phase of five additional injections in the year before enrollment in the study or a minimum of three additional injections in the 6 months before enrollment.
The baseline demographic data were notable, Dr. Dugel pointed out, for the increased number of injections that were administered before study enrollment, i.e., a mean of 12.5, with a minimum of six injections and a maximum of 38 injections. The re-treatment criteria included the findings on clinical examination, optical coherence tomography, and fluorescein angiography.
The results showed that at the 2-year time point after one application of epimacular brachytherapy, 68.1% of patients maintained their VA, 32.0% had increases in VA, and 7.5% had a gain of 15 letters or more. As a group, there was an average decrease of 6.7 letters. The average increase was 10.1 letters of VA among the patients who gained vision, Dr. Dugel reported.
Regarding the treatment burden, a mean of 4.2 injections were administered annually; 15% of patients did not receive any injections, and 38% had two or fewer injections annually.
"It was surprising to us that despite the difficult patient population in whom the vision was actually decreasing despite an increasing frequency of anti-VEGF injections, almost a third of patients had improved VA," Dr. Dugel said.
He said that it is reasonable to ask if the increase in VA was due to the increased number of anti-VEGF drug injections.