Wednesday May 31, 8:37 am ET Biogen Idec Agrees to Buy Swiss Multiple Sclerosis Drug Development Partner Fumapharm CAMBRIDGE, Mass. -- Biotechnology company Biogen Idec Inc. said Wednesday it agreed to buy privately held drug maker Fumapharm AG a day after positive results were released on a multiple sclerosis treatment.

Financial terms of the transaction were not disclosed.

Fumapharm and Biogen have been developing BG-12, a multiple sclerosis treatment that was shown in a mid-stage clinical study Tuesday to significantly reduce the number of brain lesions that cause the debilitating condition. Multiple sclerosis is an incurable disease where the immune system attacks the insulation of nerve fibers by mistake.

The Swiss company also makes the psoriasis treatment Fumaderm, which is sold in Germany.

The boards of both companies have approved the transaction, which is expected to close in two months.

In March, a Food and Drug Administration advisory panel recommended that the agency let Biogen and partner Elan Corp. resume sales of the multiple sclerosis drug Tysabri. However the agency delayed making a final decision until June on the drug, which was pulled from the market because of a link to an often-fatal brain infection.

Biogen also makes the multiple sclerosis drug Avonex.