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Comment & Response
November 19, 2014

Drugs for Macular Degeneration—Reply

Author Affiliations
  • 1George Washington University, Washington, DC
JAMA. 2014;312(19):2045. doi:10.1001/jama.2014.12748

In Reply Dr Stoilov and colleagues point out an inaccuracy in my Viewpoint: ranibizumab is not just the Fab portion of bevacizumab but rather a genetically engineered variant Fab fragment with several amino acid changes that increase binding affinity to VEGF. A correction accompanies this letter.

The implication is that these molecular differences justify the 100-fold higher price per milligram of ranibizumab vs bevacizumab. From a consumer point of view, higher price could be justified by some combination of product advantages and increased manufacturing cost. However, many experts believe there is no clinically significant advantage to ranibizumab1 and its manufacturing cost is likely to be lower because it is made in bacteria, whereas bevacizumab is made in mammalian cells.