Researchers at the Helsinki Retina Research Group at the University of Helsinki, Finland report that while two treatment protocols – either moderate or rapid extensions – do not change the visual acuity or central subfield macular thickness (CSMT), the mean number of injections was lower and the treatment interval longer in the treat-and-extend group with rapid extensions. From the research study the report concluded that at the 1-year period, the biological responses were comparable between the moderate and rapid extensions protocols. The results indicated that fewer aflibercept injections in the rapid extension protocol may be suitable, compared to the moderate protocol.
Treat-and-extend protocol strategies for several anti-VEGF agents was introduced by many research groups with the objective to reduce the frequency of visits and injections without sacrificing the efficacy of the treatment. However, according to the Finnish study, only few trials have reported results from aflibercept treat-and-extend protocols in wet AMD and the aim of the study uses two different variants of the protocol in treatment- naïve patients for wet AMD. The current study used a prospective randomized clinical trial to recruit 52 patients with treatment-naïve wet age-related macular degeneration (AMD). Patients received three monthly aflibercept injections and were then randomized 1:1 to two different dosing protocols. In treat-and-extend protocol with moderate extensions (“M”), after the loading phase the treatment interval was extended 1 week at a time up to 12 weeks and then by 2 weeks up to 16 weeks. While in comparison, in treat-and-extend protocol with rapid extensions (“R”), the interval was first extended to 8 weeks and then by 2 weeks at a time up to 16 weeks. The main outcome measure of the study was the number of given aflibercept injections and the result then was compared between protocol M or protocol R.
In the results, fifty (96%) patients completed the 1-year follow-up and this reported that at 1 year, the central subfield macular thickness (CSMT) was reduced by 194.3 ±153.6 µm in “M” protocol, compared with 194.2 ±176.6 µm with the “R” protocol (p=0.997) i.e., both of the protocols were essentially identical. Eyes with the M protocol gained 10.3 ±11.5 letters from baseline and eyes with the R protocol 11.4 ±10.6 letters (p=0.434). In addition, dry macula reported that 72% of eyes were with the M protocol, compared to 68% with the R protocol (p=0.758). At 1 year, the treatment interval was 8.5 ±2.2 weeks in the M protocol and 10.3 ±2.8 weeks in the R protocol (p=0.017), and the total number of injections 8.64 ±1.58 and 6.96 ±0.79, respectively (p<0.001). In the R extension protocol, 48% of eyes reached a 12-week treatment interval or beyond at 1 year.