from SC 13D/A
1 page
<page> 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. Bb Biotech AG Date: December 18, 1997 By: /S/ Hans-Joerg Graf Name: Hans-Joerg Graf Date: December 18, 1997 By: /S/ Dr. Victor Bischoff Name: Dr. Victor Bischoff Biotech Target S.A. Date: December 18, 1997 By: /S/ Dr. Andreas Bremer Name: Dr. Andreas Bremer Date: December 18, 1997 By: /S/ Dr. Anders Hove Name: Dr. Anders Hove Page 9 of 9
