11 EXHIBIT 99.D AGREEMENT TO FILE JOINTLY We, the undersigned, hereby express our agreement that the attached Schedule 13D is filed on behalf of each of us. HOECHST CORPORATION Date: March 21, 1996 By: /s/ David A Jenkins David A. Jenkins Vice...Agreement to File Jointly • March 22nd, 1996 • Hoechst Marion Roussel Inc • Pharmaceutical preparations
