April 10 (Reuters) - Vertex Pharmaceuticals ( VRTX )

will buy Alpine Immune Sciences ( ALPN ) for about $4.9 billion

in cash, gaining access to the biotech firm's protein-based

immunotherapies to treat autoimmune and inflammatory diseases,

the companies said on Wednesday.

The deal values each share of Alpine at $65, which

represents a premium of about 67% to the stock's close on

Tuesday, a day before Bloomberg News reported that the company

was considering options, including a potential sale, after

attracting takeover interest.

Shares of Alpine were up 36% in extended trading, while

Vertex Pharma was down about 1%.

The gene therapy developer will now have access to Alpine's

povetacicept, which is in mid-stage development for the

treatment of an autoimmune disease of the kidney called IgA

nephropathy (IgAN).

The transaction, approved by Vertex and Alpine's boards, is

expected to close in the second quarter of 2024.