June 25 (Reuters) - The U.S. Food and Drug

Administration has declined to approve AbbVie's ( ABBV ) therapy

for patients with Parkinson's disease due to problems at a

third-party manufacturer, the company said on Tuesday, marking

the second rejection for the treatment.

AbbVie ( ABBV ) added the FDA had not identified issues with the

therapy's safety or efficacy and did not request additional

trials.

The therapy ABBV-951 is a version of carbidopa-levodopa, the

standard of care for the disease. It is administered

subcutaneously, or under the skin, through an infusion pump in

order to improve patients' motor functions.

The therapy was being tested to treat patients with advanced

Parkinson's disease which causes muscle rigidity and slowness of

movement.

The so-called complete response letter was issued due to

"observations that were identified during inspection of a

third-party manufacturer", the company said.

A complete response letter is issued by the FDA indicating

the company's marketing application will not be approved by the

agency in its current form.

Last year, the regulator declined to approve the therapy and

requested additional information on the device used to

administer the treatment.

If approved, analysts estimate $619.67 million in sales for

ABBV-951 in 2026, according to LSEG data.

AbbVie ( ABBV ) said it continues to work with the FDA to bring the

therapy to patients in the United States.

Shares of the company are down marginally in early trade.