Ahead of the Bell: Medarex downgraded

A JPMorgan analyst downgraded shares of Medarex Inc. Thursday, saying the stock will trade in place until the second half of 2009, when Medarex reports critical late-stage trial data for its melanoma drug candidate ipilimumab.

Matthew Roden said mid-stage data for the drug was not very strong, and he thinks investors will wait for late-stage data that proves ipilimumab is effective as a primary treatment for advanced melanoma. Until that time, he expects the stock to trade only at the value of Medarex's cash and royalties.

Roden cut his rating to "Neutral" from "Overweight." Previously, he said, he expected strategic alternatives or more developments from the Princeton, N.J., company's pipeline. He now expects ipilimumab to reach the market in late 2010.

Medarex is developing the drug in a partnership with Bristol-Myers Squibb Co. It is designed to treat advanced metastatic melanoma, a deadly type of skin cancer.

Medarex shares finished at $6.95 Wednesday, and have traded between $6.41 and $15.69 over the past year.