Exhibit 12.1

Biogen Idec Inc and Subsidiaries
Computation of Ratio of Earnings to Fixed Charges (1)

	Years Ended December 31,
	2005		2004		2003
	(In thousands, except ratios)
Income (loss) before income tax provision (benefit)		256,195		64,093		(880,621	)
Fixed charges:
Interest expense and amortization of original issue discount on all indebtedness		17,811		18,499		15,105
Interest included in rent expense		4,828		5,312		1,960
Total fixed charges		22,639		23,811		17,065
Income (loss) before income tax provision (benefit) and fixed charges		278,834		87,904		(863,556	)
Ratio of earnings (loss) to fixed charges		12.32		3.69		—

(1) The ratio of earnings to fixed charges was computed by dividing earnings (loss) before income taxes and fixed charges by fixed charges for the periods indicated. Fixed charges include (i) interest expense and amortization of original issue discount on all indebtedness and (ii) a reasonable approximation of the interest factor deemed to be included in rental expense.