By Mariam Sunny

Dec 9 (Reuters) - AbbVie's ( ABBV ) experimental drug to

treat early Parkinson's disease helped significantly improve

patients' ability to carry out daily tasks such as eating and

walking, months after the drugmaker disclosed its success in a

separate study.

The late-stage study tested the safety and efficacy of

flexible doses of the once-daily drug, tavapadon, ranging from 5

milligrams (mg) to 15 mg, as a monotherapy, the company said on

Monday.

AbbVie ( ABBV ) acquired the drug through its $8.7 billion purchase

of Cerevel Therapeutics last year as its rheumatoid arthritis

drug Humira, once the world's best-selling treatment, faces a

sharp fall in sales due to competition from close copies.

"Although questions remain on tavapadon's competitive

profile, this shows at least some payoff for the Cerevel

transaction," said Piper Sandler analyst Christopher Raymond.

More than $40 billion was wiped off from AbbVie's ( ABBV ) market

value last month after a schizophrenia drug acquired through the

Cerevel deal failed in two separate studies.

In September, two fixed doses of tavapadon as a monotherapy

had shown significant improvement in patients in a late-stage

study.

The majority of side effects reported, such as nausea,

headache, and dry mouth, were mild to moderate in severity.

AbbVie ( ABBV ) plans to submit a marketing application to the U.S.

Food & Drug Administration next year.

The study enrolled 304 adults between the ages of 40 and 80,

who had the disease for less than three years.

There are an estimated 1 million people in the U.S. living

with Parkinson's, a progressive neurological disorder that

impairs the brain's nerve cells, thereby affecting the

production of dopamine, a neurotransmitter that regulates

functions such as memory, movement, and mood.

There is no known cure for the disease, and available

treatments only help alleviate symptoms.

The established standard of care for the disease, levodopa,

acts as a dopamine replacement agent. Tavapadon belongs to a

class of drugs known as dopamine agonists, which activate the

dopamine receptors.

(Reporting by Mariam Sunny in Bengaluru; Editing by Anil

D'Silva and Sriraj Kalluvila)