Biogen Idec says that it is delaying filing its 2004 annual report with the US Securities and Exchange Commission to allow it to assess the full impact of the recent withdrawal of its multiple sclerosis drug, Tysabri (natalizumab) [[01/03/05a]].

Biogen Idec’s fourth quarter and full-year 2004 results were announced early last month [[08/02/05b]], and do not take into account the impact of the Tysabri suspension.

The firm says that it had not completed its assessment of the impact of the Tysabri suspension, but hopes to do this and file its report with the SEC within 15 days. It expects that the principal effect of these adjustments will be to decrease 2004 pre-tax income by no more than $15 million. Pre-tax income for 2004 should, therefore, not drop below the $78 million mark.