Biogen Idec has said it will acquire privately-held Swiss drugmaker Fumapharm, adding a marketed drug for psoriasis to its portfolio and boosting its pipeline of multiple sclerosis treatments.

This is the third transaction announced by the US biotechnology firm since it revealed it planned to use some of its $2 billion cash pile for acquiring new drugs and companies to bolster its business.

The Fumapharm deal matches Biogen Idec’s strategy closely, aimed at bringing in drugs that are close to marketing approval as well as products to boost its portfolio and reduce its reliance on multiple sclerosis drug Avonex (interferon beta-1a), which has seen slowing growth as a result of competition in the market for MS drugs.

The value of the Fumapharm deal has not been disclosed, but its comes after Biogen Idec pledged $250 million to buy cancer specialist Conforma Therapeutics earlier this month, and spent $660 million licensing several antibody drugs from protein Design Labs last August.

Biogen Idec and Fumapharm have been collaborating on a drug for multiple sclerosis and psoriasis, BG-12, since October 2003. This agent has already cleared one Phase III study in psoriasis – a sector which Biogen Idec recently exited by selling off rights to its Amevive (alefacept) treatment to Japanese drugmaker Astellas - with positive Phase II data in multiple sclerosis reported earlier this week.

The acquisition brings in a psoriasis drug, Fumaderm, that is already on the market in Germany and according to the Swiss company is the leading product there for oral systemic treatment of severe psoriasis.

The results of the Phase II study, announced May 30, showed that BG-12 achieved its primary endpoint, a statistically significant reduction in the total number of gadolinium-enhancing brain lesions as measured by MRI with six months of treatment versus placebo.

“This acquisition supports our goal of developing innovative therapeutic options for people living with MS," said James Mullen, Biogen's president and chief executive, in a statement.

In addition to Avonex, Biogen Idec also has a stake alongside Irish drugmaker Elan in Tysabri (natalizumab), another MS drug that was withdrawn from sale last year after being linked to a rare and life-threatening brain disease. However, Tysabri’s use was backed by a US Food and Drug Administration (FDA) advisory panel earlier this year and could return to market in the next few weeks.

The Fumapharm transaction is expected to close within the next two months.