Biotechnology company ImClone Systems Inc finally hired its defense team, bringing in JP Morgan Chase & Co to help it weigh an unsolicited takeover offer from Bristol-Myers Squibb Co, as well as a possible plan to separate into two companies.

ImClone called Bristol’s offer, which values ImClone at $5.2 billion, too low, but said it would review the proposal. Activist investor Carl Icahn, chairman of ImClone and a large shareholder of the company, has slammed the bid, saying it “greatly undervalues the company.”

Also up for debate is ImClone antibody IMC-11F8, which is now under development. If approved for sale, ImClone has said the antibody “might have a significant competitive effect on Erbitux,” and Bristol may have no rights to market that product. Bristol previously termed its offer for ImClone “full and fair” and said it believed it has rights to the follow-on drug to Erbitux, an ImClone cancer drug.

Bringing antibodies into a takeover battle is a new twist.

ImClone’s defense team of JP Morgan will battle Bristol’s team of heavyweights, which include Citigroup, Morgan Stanley and Credit Suisse.