Regulators want an additional clinical trial for Eli Lilly’s diabetic retinopathy drug Arxxant (ruboxistaurin), the drug company said. The additional Phase 3 trial could take up to five years to complete,according to Lilly. The FDA requires the additional efficacy data before it will consider approval. An advisory committee had issued an approvable letter Aug. 18 requesting more data but delaying a decision on whether such data would come from ongoing trials or if a new trial would be required. Analysts had predicted Arxxant—which was in line to be the first approved oral treatment for the common eye disease—could have sales of at least $500 million a year. “We still believe that ruboxistaurin has potential as a treatment for diabetic eye disease and are exploring the feasibility of further development of this molecule,” said John Lechleiter, PhD, Lilly president and COO, in a statement. Trials will continue while Lilly evaluates its options. The firm submitted Arxxant to the FDA in February and received a priority, six-month review.