What previous actions has FDA taken regarding safety concerns with ESAs?
The product labels for all US marketed ESAs have been updated several times since the original approvals to incorporate new safety information. The FDA has closely monitored emerging safety information and requested post-marketing studies to address actual and potential safety concerns. These included requests for post-marketing studies to assess risks of blood clots and effects on cancer. FDA has requested and performed analyses of clinical studies to assess the relationship between safety, dose, and pharmacodynamic effects (e.g., rate of increase of red blood cells). FDA also sought advice of the ODAC in May 2004 regarding assessment of current information and design of studies to assess effects on tumor growth, increased death rate, and blood clots.
