Intravitreal Aflibercept to Treat Macular Edema From CRVO
Intravitreal Aflibercept to Treat Macular Edema From CRVO
The common therapies for CRVO treatment are laser photocoagulation for peripheral ischemia, macular laser for ME (occasionally) and intravitreal injections of anti-VEGF and steroids, which are used to reduce edema and help maintain perfusion. Currently ranibizumab and aflibercept are both FDA-approved in the treatment of CRVO-related ME, while bevacizumab is used off-label for ME with the same regimens and indications as the on-label drugs. Recently single-use vials are becoming more appealing to many clinicians. Between ranibizumab and aflibercept, the potential for less frequent dosing is a benefit if the drug truly provides longer duration in the eye and better binding of VEGF. A head-to-head trial of the drugs and comparison of equal treatment regimens would shed some light onto the question of increased efficacy and dosing regimens. Until such data is available from a randomized, blinded, control trial, the actual benefit and selected dosing regimen would be speculative.
As aflibercept's scope of indications increases (it is likely that an application will be made for FDA approval for the treatment of DME and branch RVO – all intravitreal uses for neovascular and vascular stability purposes), its presence in the marketplace is expected to increase. As more retinal specialists use aflibercept for more vascular disease in the eye, comfort in the addition of this drug to the rapidly expanding regimen of anti-VEGF agents will increase.
Currently, there has not been a defined end point on when to stop treatment. Data clearly indicates that earlier treatment of ME caused by CRVO is closely linked to better visual results. Unfortunately, all trials using anti-VEGF agents fail to direct as to when to taper or withdraw care. Many studies have continued monthly treatment for the duration of the trial, and while this is demonstrated to provide good results, the toll on patients and physicians is not accounted for. The COPERNICUS and GALILEO trials provided more clarity, with 6 months of monthly treatment switched to a PRN treatment, resulting in little change in vision. The additional injection burden during the final 18 months was 7.1 injections for sham/aflibercept PRN and 6.0 injections for aflibercept/PRN. This is close to a 3-monthly injection regimen, which is much more acceptable to patients and physicians.
This data is perhaps the most useful from a patient comfort level, knowing that injections are not likely to be indefinitely administered on a monthly basis. Until guidelines are established in the treatment of CRVO with the new arsenal of anti-VEGF agents, with or without adjuvant therapies of corticosteroids, laser and surgery, there will be many different approaches to the treatment of ME resulting from CRVO, and many different ways of defining success and treatment termination.
Expert Commentary
The common therapies for CRVO treatment are laser photocoagulation for peripheral ischemia, macular laser for ME (occasionally) and intravitreal injections of anti-VEGF and steroids, which are used to reduce edema and help maintain perfusion. Currently ranibizumab and aflibercept are both FDA-approved in the treatment of CRVO-related ME, while bevacizumab is used off-label for ME with the same regimens and indications as the on-label drugs. Recently single-use vials are becoming more appealing to many clinicians. Between ranibizumab and aflibercept, the potential for less frequent dosing is a benefit if the drug truly provides longer duration in the eye and better binding of VEGF. A head-to-head trial of the drugs and comparison of equal treatment regimens would shed some light onto the question of increased efficacy and dosing regimens. Until such data is available from a randomized, blinded, control trial, the actual benefit and selected dosing regimen would be speculative.
As aflibercept's scope of indications increases (it is likely that an application will be made for FDA approval for the treatment of DME and branch RVO – all intravitreal uses for neovascular and vascular stability purposes), its presence in the marketplace is expected to increase. As more retinal specialists use aflibercept for more vascular disease in the eye, comfort in the addition of this drug to the rapidly expanding regimen of anti-VEGF agents will increase.
Currently, there has not been a defined end point on when to stop treatment. Data clearly indicates that earlier treatment of ME caused by CRVO is closely linked to better visual results. Unfortunately, all trials using anti-VEGF agents fail to direct as to when to taper or withdraw care. Many studies have continued monthly treatment for the duration of the trial, and while this is demonstrated to provide good results, the toll on patients and physicians is not accounted for. The COPERNICUS and GALILEO trials provided more clarity, with 6 months of monthly treatment switched to a PRN treatment, resulting in little change in vision. The additional injection burden during the final 18 months was 7.1 injections for sham/aflibercept PRN and 6.0 injections for aflibercept/PRN. This is close to a 3-monthly injection regimen, which is much more acceptable to patients and physicians.
This data is perhaps the most useful from a patient comfort level, knowing that injections are not likely to be indefinitely administered on a monthly basis. Until guidelines are established in the treatment of CRVO with the new arsenal of anti-VEGF agents, with or without adjuvant therapies of corticosteroids, laser and surgery, there will be many different approaches to the treatment of ME resulting from CRVO, and many different ways of defining success and treatment termination.
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