EXHIBIT 4.1 FIRST AMENDMENT TO THE RIGHTS AGREEMENT AND CERTIFICATION OF COMPLIANCE WITH SECTION 27 THEREOF Pursuant to Section 27 of the Rights Agreement (the "Agreement") dated as of July 22, 1997, between IDEC PHARMACEUTICALS CORPORATION, a...Rights Agreement • January 4th, 1999 • Idec Pharmaceuticals Corp / De • Biological products, (no disgnostic substances)
