By Colin Kellaher

Eli Lilly & Co. on Tuesday said it is moving forward with a its most promising Alzheimer's disease drug but pulling the plug on another program targeting the memory-loss disease.

The Indianapolis drug maker said it initiated a rolling submission with the U.S. Food and Drug Administration for donanemab, seeking accelerated approval for the drug in early Alzheimer's.

The move comes after the FDA earlier this year gave an accelerated green light to Biogen Inc.'s Aduhelm, the first new Alzheimer's drug in nearly two decades.

Like Aduhelm, Lilly's donanemab is aimed at reducing a sticky protein called amyloid in the brain. The FDA based its approval of Biogen's drug on the likelihood that reducing amyloid would result in a slowing of cognitive decline, though the agency acknowledged that the benefit was uncertain.

The FDA last month granted breakthrough-therapy designation to donanemab, which is currently in Phase 3 studies. The designation aims to expedite the development and review of a drug for serious conditions when preliminary clinical evidence shows the drug may show substantial improvement over available therapies.

Eli Lilly on Tuesday said it plans to conduct a Phase 3 head-to-head clinical study comparing donanemab to Aduhelm to assess superiority of brain amyloid plaque clearance in early symptomatic Alzheimer's disease, with enrollment slated to begin this year.

Analysts at Mizuho said donanemab is one of two key pipeline assets, along with the diabetes drug candidate tirzepatide, that are likely to drive growth for Lilly in the coming years.

Still, as Eli Lilly advances its donanemab efforts, the company said it is ending development of zagotenemab, another Alzheimer's drug candidate targeting tangles of tau protein in the brain.

The company said zagotenemab didn't meet the primary endpoint in a Phase 2 study in early symptomatic Alzheimer's and was unable to modulate tau spread in the brain.

Biogen earlier this year suffered its own setback in its tau-targeting efforts after its investigational anti-tau antibody gosuranemab missed its targets in a Phase 2 study, prompting the Cambridge, Mass., company to end development of the drug.

An Eli Lilly representative said the company remains committed to tau as a high conviction target in Alzheimer's and plans to continue studying tau biology, including inhibition of tau aggregation, with a small molecule O-GlcNAcase inhibitor currently in the clinic.

Write to Colin Kellaher at colin.kellaher@wsj.com

(END) Dow Jones Newswires

10-26-21 1130ET