EXHIBIT 11 BIOGEN, INC. and SUBSIDIARIES Computation of Earnings Per Share (in thousands, except per share amounts) 1994 1993 1992 Primary earnings (loss) per share Weighted average number of shares outstanding. . . . . . . . . . . . . 32,774 31,972 31,025 Shares deemed outstanding from the assumed exercise of stock options and warrants. . . . . . .. -- 2,748 3,173 Total. . . . . . . . . . . . . . . . . 32,774 34,720 34,198 Net income (loss) . . . . . . . . . . $ (4,897) $ 32,417 $ 38,311 Primary earnings (loss) per share of common stock . . . . . . . $ (0.15) $ 0.93 $ 1.12 Fully diluted earnings (loss) per share Weighted average number of shares outstanding. . . . . . . . . 32,774 31,972 31,025 Shares deemed outstanding from the assumed exercise of stock options and warrants. . . . . . . . -- 3,152 4,404 Total. . . .. . . . . . . . . . . . . . 32,774 35,124 35,429 Net income (loss). . . . . . . . . . . $ (4,897) $ 32,417 $ 38,311 Fully diluted earnings (loss) per share of common stock . . . . . $ (0.15)(a)$0.92(a) $ 1.08 (a) This calculation is submitted in accordance with Regulation S-K item 601 (b) (11) although not required by Footnote 2 to Paragraph 14 of APB Opinion No. 15 because it results in dilution of less than 3%.