A pilot, “look-back” study of information about 106 patients with “wet” age-related macular degeneration (AMD) treated at the Wilmer Eye Institute at Johns Hopkins Medicine has revealed that nearly half of patients treated with aflibercept could safely stop eye injection therapy after one year without further vision loss. Only 17% of patients taking another commonly used wet AMD therapy, bevacizumab, were able to safely wean from the drug at a year.
The paper was published early online November 22 by the Journal of Clinical Investigation.
The findings build on evidence from a previous study led by the Johns Hopkins researchers that found potentially a third of patients with wet AMD could safely pause therapy after one year of monitoring by a physician.
Aflibercept and bevacizumab are the two most frequently used therapies for the treatment of wet AMD. It was previously shown that the interval between treatments for aflibercept (approximately $2,000 per treatment) is longer, and that aflibercept may be more effective than bevacizumab (approximately $100 per treatment) for treating some patients with wet AMD. But, at more than 10 times the cost of monthly bevacizumab, whether this small benefit justifies the additional expense of bimonthly aflibercept remains under debate among clinicians, say the researchers.
In the study, the team reviewed records of the treatment outcomes of 106 people with wet AMD who were treated at the Johns Hopkins Wilmer Eye Institute between 2013 and 2020 in two Maryland locations.
Each patient had received a monthly injection for the first three months of therapy with either aflibercept or bevacizumab.
At each subsequent visit, patients were evaluated and those whose wet AMD remained inactive had the interval between visits extended by two weeks. If this interval could be safely extended to 12 weeks, treatment was paused and the patient was closely monitored without treatment. Patients were defined as “weaned” off treatment only if they had stable vision and did not require an eye injection for at least 30 weeks following their last treatment during this monitoring period.
After the first three mandatory monthly injections, patients receiving aflibercept demonstrated a modest advantage over bevacizumab for improvement in vision, consistent with prior studies.
At six months, while determining the ideal interval between treatments for each individual patient, the advantage for monthly injections of aflibercept was no longer observed. However, when the interval between treatments was extended, patients receiving bevacizumab had a higher rate of vision loss than those receiving aflibercept.
At one year, the records showed that 50% (30 of patients 60) of patients treated with aflibercept were considered weaned off therapy, compared to 17% of patients (8 of 46) treated with bevacizumab.
For patients who still needed treatment, the intervals between injections was 44% longer (13.1 weeks versus 9.1 weeks) for patients treated with aflibercept than those treated with bevacizumab. Fluid accumulation and progressive vision loss were similar in the two groups.
The total number of injections for patients treated with aflibercept was reduced by 10% (7.2 versus eight) over one year when compared with the standard bimonthly treatment schedule, while the total injections for patients treated with bevacizumab was reduced by 33% (8.7 versus 13) when compared with the standard monthly treatment schedule.
The researchers monitored 56 of the 106 patients for an additional year — 13 of 27 (48%) patients treated with aflibercept remained off treatment at the end of two years, compared with eight of 29 (28%) patients weaned off bevacizumab. Although this was an improvement for patients receiving bevacizumab compared to the first year, it was still an inferior result to that for patients receiving aflibercept.
Overall, at two years the number of total injections for patients treated with aflibercept was reduced by 27% (10.2 vs. 14) when compared with the standard bi-monthly treatment schedule while the total injections for patients treated with bevacizumab was reduced by 44% (14 vs. 25) when compared with the standard monthly treatment schedule.
