14 EXHIBIT 99.C AGREEMENT TO FILE JOINTLY We, the undersigned, hereby express our agreement that the Schedule 13D to which this Agreement is appended is filed on behalf of each of us. HOECHST MARION ROUSSEL, INC. Date: March 28, 1997 By: /s/ James P....Agreement to File Jointly • March 28th, 1997 • Hoechst Marion Roussel Inc • Pharmaceutical preparations
