1 JOINT FILING AGREEMENT We, the undersigned, hereby express our agreement that the attached Schedule 13D (including all amendments thereto) is filed on behalf of each of the undersigned.Joint Filing Agreement • September 19th, 1997 • Bb Biotech Ag
1 SERIES B PREFERRED STOCK PURCHASE AGREEMENT Alexion Pharmaceuticals, Inc. 25 Science Park New Haven, CT 06511 Ladies & Gentlemen: The undersigned, Biotech Target S.A. (the "Investor"), hereby confirms its agreement with you as follows: 1. This...Series B Preferred Stock Purchase Agreement • September 19th, 1997 • Bb Biotech Ag • Delaware
