March 12 (Reuters) - The U.S. health regulator's staff on Tuesday flagged concerns that the late-stage trial data on Geron's anemia drug does not show whether the risks of treatment with imetelstat are outweighed by the potential benefit, documents released ahead of a meeting of independent experts showed.

(Reporting by Christy Santhosh and Pratik Jain in Bengaluru; Editing by Shailesh Kuber)