Comparing Anti-VEGF Agents for Neovascular AMD
Comparing Anti-VEGF Agents for Neovascular AMD
Comparison of Age-related Macular Degeneration Treatments Trials (CATT) Research Group, Martin DF, Maguire MG, et al
Ophthalmology. 2012;119:1388-1398
The Comparison of Age-related Macular Degeneration Treatments Trials (CATT) Research Group conducted a randomized, multicenter, noninferiority trial that compared the anti-vascular endothelial growth factor (VEGF) agents ranibizumab and bevacizumab in the treatment of neovascular age-related macular degeneration (AMD). Intravitreal injections of the drugs were administered monthly or as needed on the basis of any fluid found on monthly optical coherence tomography evaluation. At 1 year, patients receiving monthly treatments were randomly reassigned to monthly or as-needed dosing regimens of the same drug. The primary outcome was the mean change in visual acuity at 1 year, with a later analysis at 2 years. Another goal was to determine whether outcomes were affected by less-than-monthly treatments.
At 1 year, monthly ranibizumab was equivalent to monthly bevacizumab, and as-needed ranibizumab was equivalent to as-needed bevacizumab. The rates of systemic adverse events were similar between the drugs, but more patients receiving bevacizumab than ranibizumab (24.1% vs 19.0%; risk ratio, 1.29; 95% confidence interval, 1.01-1.66) experienced serious adverse events, 80.5% of which involved hospitalization.
At 2 years, the drugs were again found to be equivalent, but monthly dosing resulted in a greater gain in visual acuity than the as-needed dosing regimen. Patients who were switched from monthly to as-needed treatment schedules experienced a decrease in visual acuity similar to if they had been on as-needed treatment from the beginning of the trial. This counteracted the notion that a loading dose is helpful, because after receiving monthly injections and switching to treatment as needed, the results were no better than if the patients had received treatment as needed from the start.
Systemic adverse event rates were similar between drugs, but a greater proportion of patients receiving bevacizumab continued to experience serious adverse events. What is most interesting and needs further study is that these events were in areas not previously known to be related to anti-VEGF therapy. In addition, patients who were treated as needed had more adverse events than the patients who were treated monthly. Therefore, those who received fewer injections had more adverse events, which is counterintuitive and requires further study.
Geographic atrophy also developed, ranging from 12.9% to 25.8% among groups treated with the same dosing regimen for 2 years. Rates of geographic atrophy were higher in the groups receiving monthly treatment and higher in the patients receiving ranibizumab. It will be interesting to see if this finding is corroborated by other studies.
Abstract
Ranibizumab and Bevacizumab for Treatment of Neovascular Age-Related Macular Degeneration: Two-Year Results
Comparison of Age-related Macular Degeneration Treatments Trials (CATT) Research Group, Martin DF, Maguire MG, et al
Ophthalmology. 2012;119:1388-1398
Study Summary and Viewpoint
The Comparison of Age-related Macular Degeneration Treatments Trials (CATT) Research Group conducted a randomized, multicenter, noninferiority trial that compared the anti-vascular endothelial growth factor (VEGF) agents ranibizumab and bevacizumab in the treatment of neovascular age-related macular degeneration (AMD). Intravitreal injections of the drugs were administered monthly or as needed on the basis of any fluid found on monthly optical coherence tomography evaluation. At 1 year, patients receiving monthly treatments were randomly reassigned to monthly or as-needed dosing regimens of the same drug. The primary outcome was the mean change in visual acuity at 1 year, with a later analysis at 2 years. Another goal was to determine whether outcomes were affected by less-than-monthly treatments.
At 1 year, monthly ranibizumab was equivalent to monthly bevacizumab, and as-needed ranibizumab was equivalent to as-needed bevacizumab. The rates of systemic adverse events were similar between the drugs, but more patients receiving bevacizumab than ranibizumab (24.1% vs 19.0%; risk ratio, 1.29; 95% confidence interval, 1.01-1.66) experienced serious adverse events, 80.5% of which involved hospitalization.
At 2 years, the drugs were again found to be equivalent, but monthly dosing resulted in a greater gain in visual acuity than the as-needed dosing regimen. Patients who were switched from monthly to as-needed treatment schedules experienced a decrease in visual acuity similar to if they had been on as-needed treatment from the beginning of the trial. This counteracted the notion that a loading dose is helpful, because after receiving monthly injections and switching to treatment as needed, the results were no better than if the patients had received treatment as needed from the start.
Systemic adverse event rates were similar between drugs, but a greater proportion of patients receiving bevacizumab continued to experience serious adverse events. What is most interesting and needs further study is that these events were in areas not previously known to be related to anti-VEGF therapy. In addition, patients who were treated as needed had more adverse events than the patients who were treated monthly. Therefore, those who received fewer injections had more adverse events, which is counterintuitive and requires further study.
Geographic atrophy also developed, ranging from 12.9% to 25.8% among groups treated with the same dosing regimen for 2 years. Rates of geographic atrophy were higher in the groups receiving monthly treatment and higher in the patients receiving ranibizumab. It will be interesting to see if this finding is corroborated by other studies.
Abstract
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