FDA staff proposes narrow approval for Lilly’s Alzheimer’s drug

U.S. drug regulatory staffers are considering a more targeted approval for Eli Lilly & Co.’s experimental Alzheimer’s disease treatment than the company wants, potentially limiting the market for a would-be blockbuster.

The Food and Drug Administration staff questioned whether Lilly’s drug, donanemab, should be approved for all patients with early-stage Alzheimer’s, according to a report Thursday, or restricted to only those with moderate levels of a disease-related protein called tau. Lilly’s study excluded patients with low or no tau in their brains.

The FDA will convene a panel of expert advisers Monday to discuss Lilly’s supporting evidence and whether donanemab’s benefits outweigh its risks. Donanemab would compete against Leqembi, an approved Alzheimer’s medicine from Biogen Inc. and Eisai Co.