EXHIBIT 2 AMENDMENT NO. 1 TO RIGHTS AGREEMENT Amendment No. 1 to Rights Agreement (the "Amendment"), made as of August 16, 2004, by and among Vion Pharmaceuticals, Inc. a Delaware corporation (the "Company"), and American Stock Transfer & Trust...Rights Agreement • August 16th, 2004 • Vion Pharmaceuticals Inc • Biological products, (no disgnostic substances)
