Health Winners & Losers: Bristol, ImClone

Biotech stocks made good water cooler talk Thursday as a few prospective merger stories opened to new chapters.

A day after ImClone(IMCL Quote) announced that a mystery shopper has bid $70 a share for the company, Bristol-Myers Squibb(BMY Quote) said it's standing by its own proposal. The company scorned ImClone for how the company handled and assessed the $60-a-share offer it made in July.

Bristol and ImClone appear to disagree on who owns the rights to a next-generation version of cancer drug Erbitux IMC-11F8 -- a crucial matter to both companies and any potential buyers.

Bristol shares were up $0.10, or 0.55%, at $21.80, while ImClone was down $0.98, or 1.44%, at $66.96.

In other drama, King Pharmaceuticals(KG Quote) increased its bid for pain drug company Alpharma(ALO Quote), offering to purchase all of the outstanding shares of its Class A Common Stock for $37 a share, up from $33. King said that Alpharma has privately rejected this bid, and it is prepared to take it directly to shareholders.

The new offer is a 67% premium to Alpharma's closing price on Aug. 4, the day of King's private written proposal to Alpharma, and a 54% premium over the closing price on Aug. 21, the last trading day before the public learned about the offer.

Meanwhile, Alpharma issued a statement urging shareholders not to take action until it can announce its official position. The board said it would review the proposal with its financial and legal advisors and make a recommendation within 10 business days.