Pan-VEGF blocker sustained benefits in AMD patients through extended follow-up period

FORT LAUDERDALE, Fla. — A novel VEGF-blocking agent known as VEGF Trap-Eye has been shown to sustain improvement in visual acuity and decrease in retinal thickness after 32 weeks, according to the results of a study presented here.

Diana V. Do, MD, one of the study investigators from Wilmer Ophthalmological Institute, presented interim data from the prospective, multicenter phase 2 trial at the Association for Research in Vision and Ophthalmology meeting.

VEGF Trap-Eye (Regeneron Pharmaceuticals/Bayer HealthCare AG) was studied in 159 patients with age-related macular degeneration who were randomly assigned to five dosing groups and treated with the agent in one eye, according to Dr. Do. Two groups initially received monthly doses of 0.5 mg or 2 mg for 12 weeks, and three groups received 0.5 mg, 2 mg or 4 mg of VEGF Trap-Eye at baseline and at week 12, she said.

After this initial fixed-dosing schedule phase, patients received the same doses of therapy, only on an as-needed basis governed by the physicians' assessment of pre-selected criteria, she said.

"At week 16, 58% to 84% of subjects gained visual acuity, and this effect was sustained and increased through 32 weeks of follow-up," Dr. Do said.

All groups in the study maintained their improvement in visual acuity — a mean of 6.6 letters — through the 32-week follow-up visit. They also maintained a decrease in retinal thickness, demonstrating a mean 137-µm decrease compared with baseline.

Investigators said the groups that were initially dosed quarterly, although they maintained their functional and anatomical gains, did not demonstrate as much improvement as those who initially were dosed monthly.

The researchers said there were no serious drug-related adverse events. There was one reported case of culture-negative endophthalmitis/uveitis in the treated eye, but this was not considered to be drug-related. Other non-serious effects were those typically associated with intravitreal injections.

Researchers also noted a "statistically significant reduction in [choroidal neovascularization] leakage and CNV lesion size, so it suggests that VEGF Trap-Eye causes a regression of CNV leakage," Dr. Do said.

Although the researchers are not certain what causes the durability of effect, Dr. Do said they hypothesize that the agent's unique molecular structure lends it "greater bioactivity and longer sustainability of action." The durability is one factor that will be studied in two simultaneous phase 3 studies, VIEW 1 and VIEW 2, that are currently under way to evaluate two dosing schedules at 4-week and 8-week intervals compared with ranibizumab administered every 4 weeks.