Extensive analysis confirms treat-and-extend regimens reliable for AMD
In patients with age-related macular degeneration managed by a treat-and-extend regimen, the visual acuity generally was maintained; lesion reactivation occurred frequently at about eight weeks; and longer induction phases between treatments was associated with worse outcomes.
By Lynda Charters; Reviewed by Mark C. Gillies, MBBS, PhD
An extensive analysis of data garnered from the Fight Retinal Blindness (FRB) Project indicated that the treat-and-extend regimens used to manage patients with neovascular age-related macular degeneration (AMD) are reliable alternative approaches that achieve good outcomes compared with monthly and as-needed regimens.
In this large database observational study, in which patients were in the maintenance phase of treatment with anti-vascular endothelial growth factor (anti-VEGF) drugs, the mean visual acuity level was maintained and the median interval of injections gradually increased to about 2 months after the first year of the treat-and-extend regimens. Reactivation of the AMD lesions occurred most often at about 8 weeks.
Mark C. Gillies, MBBS, PhD, who presented the study data on behalf of the Fight Retinal Blindness project, explained that the treat-and-extend regimen was defined as administration of monthly treatment until the lesions became inactive; stepwise extension of the treatment interval when the lesion was inactive; and reduction of the treatment interval when the lesion became active. The rationale for treat-and-extend regimens was based on previous observational studies that reported good outcomes with fewer injections of anti-VEGF drugs.
Dr. Gillies is professor, Department of Clinical Ophthalmology, The University of Sydney, and director, Macula Research Group, The Save Sight Institute, Sydney Medical School, University of Sydney, Australia.
Study describes protocol segments
The study investigators sought to describe the treatment patterns, disease activity, and visual outcomes during the maintenance phase of the treat-and-extend protocol and to compare the primary outcomes between eyes with short induction times, defined as 3 or fewer injections of anti-VEGF drugs that achieved lesion inactivation, and eyes with long induction times. The maintenance phase was defined as starting from the first visit that the practitioner graded the neovascular lesion as inactive, Dr. Gillies explained.
The study, published in Ophthalmology (2016;123:2393-2400), included 2,096 eyes of 1,698 patients who were managed with a treat-and-extend regimen out of 6,269 eyes in the FRB database. All eyes had been followed for a minimum of 12 months from the first grading of lesion inactivity. Patients were excluded from the study if they had persistently active lesions.
Dr. Gillies reported that about 50% of eyes were treated at intervals of 8 or fewer weeks at the 3-year time point. The median interval when the eyes became stable was about 1 year into the maintenance phase.
Importantly, the visual acuity was maintained during the maintenance period. The mean change from baseline at the start of the maintenance phase was an increase of 4.3 letters.
The mean change in the visual acuity 3 years after the start of the maintenance phase was an overall decrease of 1.5 letters. In the eyes with a short induction time, the visual acuity decreased by 0.5 letters, compared with a decrease of 3.6 letters in the eyes with a long induction time, according to Dr. Gillies.
One-year out
The data analysis also showed that 50% of eyes had lesions that reactivated with the first year of the maintenance period, with the most frequent time to reactivation at 8 weeks. This occurred in 17.4% of eyes.
“The long-induction eyes reactivated sooner than the short-induction eyes,” Dr. Gillies said.
When considering the risk of recurrence of the first lesion, the study found, “The risk of reactivation by visit increased with increasing interval, increasing substantially beyond 12 weeks and reaching 36.5% if the interval was 20 weeks or more from the previous injections,” Dr. Gillies pointed out.
At 16 weeks, the risk of reactivation was 5.6% compared with 15.6% at 20 weeks. Eyes with a longer induction phase had worse visual outcomes in the maintenance phase, and earlier and more frequent disease reactivation, although they received injections less frequently, according to Dr. Gillies.
Mark C. Gillies, MBBS, PhD
This article was adapted from a presentation Dr. Gillies delivered at the Retina Subspecialty Day held prior to the 2017 American Academy of Ophthalmology. Dr. Gillies has no financial interest in any aspect of this report. The study was supported by grants from the Royal Australian NZ College of Ophthalmologists Eye Foundation and the National Health and Medical Research Council in Australia.
