Icahn said he would immediately launch a search for a chief executive with biotechnology experience and push the company's troubled Erbitux medicine.
The board also said Wednesday that Joseph L. Fischer has resigned as interim chief executive, effective Tuesday. In addition three board members will not stand for re-election: Dr. Vincent T. DeVita, Jr., John A. Fazio and William R. Miller.
Further, all director fees are being waived for six months and all option grants are being waived for the next year.
"The board fees and option grants at ImClone have been egregious, especially in light of the fact that shares have declined from a high of $86 to the current price of $30 in the past three years," said Icahn. "The options given to directors in corporate America have become disturbingly unrealistic, given that there is little correlation between the number of options granted and the performance of the companies being governed."