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.