July 31 (Reuters) - Biogen raised its annual

profit forecast on Thursday, betting on strong demand for its

rare disease drugs such as Skyclarys to offset declining sales

of its older multiple sclerosis drugs.

Shares of the drugmaker rose nearly 4% in premarket trading.

On an adjusted basis, Biogen expects 2025 profit between

$15.50 and $16.00 per share, compared with its previous forecast

of $14.50 to $15.50.

It earned $5.47 per share in the second quarter, topping

analysts' average estimate of $3.86 per share, according to data

compiled by LSEG.

The drugmaker has focused on deals, cost-cutting

measures and newer drugs to address investor pressure for

growth, amid declining sales of its aging multiple sclerosis

drugs and slow take-up of its Alzheimer's treatment Leqembi.

U.S. sales of Leqembi, which the company sells with

Japan's Eisai ( ESALF ), were $63 million for the second quarter.

The Wall Street consensus estimate was at $60.5 million,

according to brokerage Jefferies.