ANCHOR study of time course of visual acuity changes: ranibizumab benefit stable over 2 years

Analysis of the time course of visual acuity outcomes during the first year of the ANCHOR study indicates that the mean visual acuity benefit of ranibizumab (Lucentis, Genentech) compared with photodynamic therapy (PDT) with verteporfin (Visudyne, Novartis) was observed after the first month of treatment, but that even patients who did not show this early benefit might respond later in the treatment course, said Jeffrey Heier, MD, Ophthalmic Consultants of Boston.

"The key visual acuity endpoints of the [ranibizumab] study were quite robust," Dr. Heier said. "The primary outcome was prevention of moderate vision loss at 1 year, which occurred in more than 90% of the patients treated with ranibizumab compared with about two-thirds of the patients who received PDT. At 2 years, the results were well-maintained."

Thirty-six to forty percent of patients in the ranibizumab groups had a gain in visual acuity of three lines or more compared with only 6% in the PDT group. At 2 years, this result was maintained. The mean change in vision at 1 year with ranibizumab, which was a four-line difference in visual acuity between the ranibizumab groups and the PDT group, was maintained at the 2-year time point.

"Moderate vision loss was unlikely to occur in the ranibizumab groups," Dr. Heier said. "This was maintained throughout the course of the study. In the PDT group, a fair amount of moderate vision loss occurred during year 1 and was stable over year 2. Most of the gains in visual acuity occurred during the first 3 to 4 months in the ranibizumab patients. There still were patients who gained the same degree of vision during the subsequent several months. The vision tended to stabilize at the 1-year time point and remained stable. The patients treated with PDT were unlikely to have this gain, and their vision remained stable.

"During the first year of the ANCHOR study, the superiority of ranibizumab over PDT was evident by 1 month after the initial treatment and this increased over time throughout 12 months," Dr. Heier concluded. "Some patients whose response to ranibizumab treatment by month 3 was a decrease in visual acuity ended up having some letter gain or even a gain of 15 or more letters compared with baseline by month 12. The treatment benefit at 12 months was maintained at 24 months."