By Bhanvi Satija and Julie Steenhuysen

June 6 (Reuters) - An FDA analysis of trial data for Eli

Lilly's ( LLY ) experimental Alzheimer's drug donanemab released

on Thursday revealed no red flags, but raised questions about

safety of the treatment for patients with early-stage disease.

The drug is a potential rival to Eisai ( ESALF ) and Biogen's

Leqembi, which won approval last July.

Both treatments are antibodies designed to remove toxic beta

amyloid plaques from the brains of people with early Alzheimer's

disease.

An outside panel of FDA advisers will consider the staff's

view during a meeting on Monday in which they will vote on

whether the drug's benefits outweigh its risks, according to

documents published on the agency's website. The panel's

recommendations are non-binding but typically followed by the

U.S. Food and Drug Administration.

If donanemab is approved, FDA staff said they expect its

prescribing label to highlight several risks and strategies to

mitigate those risks, which include brain swelling and bleeding,

especially in people with two copies of a gene called ApoE4.

Post-approval requirements that may also be requested

include expedited reporting of any deaths in ongoing studies of

the drug and collection of data about side effects through a

patient registry, FDA staff reviewers added.

At least two analysts said they expect donanemab will be

approved.

Drugs like donanemab and Leqembi, which are designed to slow

disease progression, represent a new era in the treatment of

Alzheimer's, after three decades of failed attempts to find

treatments to fight the fatal mind wasting disease.

RBC analyst Brian Abrahams said in a research note that

overall, the agency's comments may slightly favor Leqembi due to

fewer adverse side effects, but with the FDA appearing inclined

to approve the Lilly drug.