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                                                                    EXHIBIT 23.1


                         [LETTERHEAD OF ARTHUR ANDERSEN]


CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

As independent public accountants, we hereby consent to the incorporation by
reference in this Registration Statement of our report dated September 5, 2000
(except with respect to the matter discussed in Note 15 as to which the date is
September 22, 2000) included in Alexion Pharmaceuticals, Inc.'s Form 10-K for
the year ended July 31, 2000 and to all references to our Firm included in this
Registration Statement.

/s/ ARTHUR ANDERSEN LLP

Hartford, Connecticut
September 12, 2001