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Leqembi slows cognitive decline by 34% after four years

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No new safety issues found over four-year study period

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FDA decision on injectable version expected by August 31

By Deena Beasley

July 30 (Reuters) - Eisai ( ESALF ) and Biogen's

Alzheimer's drug Leqembi continued to slow progress of the

disease with no new safety issues four years into treatment,

according to new data presented at a medical meeting on

Wednesday.

An injectable version of the drug, currently given by

intravenous infusion, is under U.S. regulatory review.

The best results were seen in people who started treatment

while in the earliest stages of the brain-wasting disease.

In a pivotal trial of patients with early-stage Alzheimer's,

Leqembi was shown to slow cognitive decline by 27% compared to a

placebo after 18 months - data that supported the drug's U.S.

approval in 2023.

The companies continued to follow about 95% of patients

enrolled in that trial. The latest results show that after four

years, Leqembi slowed cognitive decline by 34% compared to what

would be expected in similar patients who did not receive

treatment.

Leqembi targets protofibrils - toxic building blocks that

eventually form clumps in the brain known as amyloid plaques, a

hallmark of Alzheimer's disease.

There were no new safety findings over the four-year period.

Brain swelling and bleeding associated with drugs that work by

removing amyloid plaque from the brain largely occurred within

the first six months of treatment, according to data presented

at the Alzheimer's Association International Conference in

Toronto.

More than 50% of patients who started treatment in the

earlier stages of Alzheimer's continued to show improvement in

clinical scores after four years on Leqembi.

Eisai ( ESALF ) is conducting a separate study of Leqembi in

pre-symptomatic Alzheimer's patients that is due to conclude in

late 2027. Eli Lilly ( LLY ) is also studying its Alzheimer's

drug Kisunla in people who have detectable disease pathology,

but show no noticeable cognitive decline.

The U.S. Food and Drug Administration, where recent job cuts

have raised questions about review times, is slated to decide by

August 31 whether to approve an injectable version of Leqembi

that could be given to patients at home or at medical

facilities.

Lynn Kramer, Eisai's ( ESALF ) chief clinical officer, said

interactions with the FDA "have been right on schedule. They

have been communicating with us all the time in an expected

manner."

He said the new formulation "will be very helpful to

starting new patients" on the drug, which is continuing to see

"escalating usage."

Eisai ( ESALF ) will report its latest quarterly results next week,

while Biogen will report results on Thursday.