The FDA has declined to grant Accelerated Approval for donanemab — Eli Lilly’s entry into the antiamyloid antibody race — saying there isn’t enough long-term data to support such a move.

Lilly said the agency wants to see safety data on at least 100 patients who have taken the drug continuously for at least 12 months. “No other deficiencies in the application were noted,” the company said.

Lilly hoped to gain accelerated approval with its phase 2 TRAILBLAZER-ALZ data. But the study design proved the downfall of that hope. TRAILBLAZER allowed patients to complete their course of treatment after achieving a prespecified amyloid reduction goal. But donanemab worked so fast that fewer than 100 patients ended up taking it for a full year.

The company will now pursue a traditional approval later this year, based on results from the ongoing confirmatory phase 3 trial, TRAILBLAZER-ALZ 2. The company expects topline data around the middle of this year.