Implications of the comparisons of age-related macular degeneration treatments trials on clinical practice: what have we learned?

TOPIC: Discussion of Comparisons of Age-Related Macular Degeneration (AMD) Treatments Trials (CATT) results and the potential impact on neovascular AMD treatment.

CLINICAL RELEVANCE: Ranibizumab and bevacizumab are most commonly used for treatment of neovascular AMD. Although bevacizumab costs less, its use primarily has been based on retrospective studies without level 1 medical evidence. Thus, there was an unmet need to determine whether there is any difference in efficacy and safety between the 2 agents when used monthly or as needed (pro re nata [PRN]).

METHODS: Review of CATT (focusing on 1-year data because 2-year data were not released at the time of this symposium), a randomized clinical trial evaluating the efficacy and safety of monthly and PRN dosing of ranibizumab and bevacizumab.

RESULTS: At the 1-year primary end point, eyes that received monthly ranibizumab gained an average of 8.5 letters; those that received monthly bevacizumab gained a mean of 8 letters. Eyes randomized to PRN ranibizumab gained an average of 6.8 letters; those randomized to PRN bevacizumab gained a mean of 5.9 letters. In the pairwise comparisons, PRN bevacizumab compared with monthly bevacizumab and PRN bevacizumab compared with monthly ranibizumab both were found to be inconclusive. At the 2-year end point, eyes that received monthly ranibizumab gained an average of 8.8 letters; those that received monthly bevacizumab gained a mean of 7.8 letters; those randomized to PRN ranibizumab gained an average of 6.7 letters; those randomized to PRN bevacizumab gained a mean of 5 letters. A higher rate of serious systemic adverse events also was detected among bevacizumab-treated subjects.

CONCLUSIONS: The CATT demonstrated that PRN ranibizumab is equivalent to monthly ranibizumab at the 1-year primary outcome. Monthly bevacizumab also is equivalent to monthly ranibizumab at the 1-year end point. The 2-year data showed less visual acuity gain with PRN dosing of either drug than monthly dosing.