Reworks paragraph 3, adds analyst comment in paragraph 8

Oct 28 (Reuters) - AbbVie ABBV.N will buy Aliada Therapeutics for $1.4 billion in cash, it said on Monday, gaining access to the privately held therapy developer's Alzheimer's disease candidate as the U.S. drugmaker increases its neuroscience focus.

Faced with slowing demand for Humira following the launch of biosimilar versions in the U.S., AbbVie this year bought neuroscience drug developer Cerevel Therapeutics and cancer drug developer ImmunoGen in deals worth around $19 billion in total.

Aliada's ALIA-1758, an antibody for Alzheimer's in early-stage development, could be a potential best-in-class therapy, AbbVie said.

ALIA-1758 utilizes a protein called transferrin in the blood that carries iron to transport an antibody to degrade and eliminate amyloid beta plaques, which are protein deposits in the brain that are a sign of Alzheimer's.

"Many promising CNS-targeted therapies fail to reach late-stage trials due to their inability to cross the blood-brain barrier," Aliada's medical chief Michael Ryan said.

"Our (drug delivery) platform addresses this challenge directly, efficiently delivering targeted drugs and potentially transforming how we treat neurological diseases."

Amyloid plaques were recently validated as a therapeutic target with the approvals of Biogen's BIIB.O Leqembi and Eli Lilly's LLY.N Kisunla but Alzheimer's remains a high-risk indication, said BMO analyst Evan Seigerman.

Alzheimer's drug development has seen several failures, including Roche's gantenerumab and Biogen's now-withdrawn first drug for the disease, Aduhelm.

The number of people with Alzheimer's is projected to double to nearly 14 million by 2060 from 6.9 million in 2020, the U.S. Centers for Disease Control and Prevention has said.

The Aliada deal is expected to close by the end of this year.

AbbVie's neuroscience therapies, which include Botox for migraines and bipolar drug Vraylar, brought in $4.13 billion in sales in the first half of 2024, a 15.3% jump from a year earlier. Humira sales dropped 32.7% during the period.

Shares of Chicago-based AbbVie were up 1% in morning trade.

(Reporting by Sriparna Roy and Puyaan Singh in Bengaluru; Editing by Shilpi Majumdar and Sriraj Kalluvila)

((Sriparna.Roy@thomsonreuters.com;))