The FDA late last week asked Eli Lilly to submit more data about its experimental diabetic retinopathy drug Arxxant before it can be approved for sale. The two-page letter Lilly received from the FDA doesn’t make clear whether Lilly will have to conduct an entirely new patient trial or if the company can satisfy the agency’s request for more information by re-analyzing data already in hand, a Lilly spokeswoman told The Indianapolis Star newspaper. If Lilly has to conduct a new clinical trial, it is likely that the marketing of Arxxant would be set back by several years. The FDA had agreed to do an expedited six-month review of the Arxxant application, given Lilly’s urgency to get a treatment on the market. If approved, Arxxant would have been the first drug on the market to treat diabetic retinopathy, a deterioration of vision that commonly afflicts people with diabetes. Analysts have predicted Arxxant could become a $1 billion-a-year blockbuster by 2010.