Medarex, Bristol-Myers Report Drug Data

Biopharmaceutical company Medarex Inc. and partner Bristol-Myers Squibb Co. said Monday one of three studies evaluating cancer drug ipilimumab in patients with advanced melanoma failed to meet its main goal.

Medarex's shares plummeted in after-hours trading.

The companies did not report full data on the other two studies. The three studies evaluated ipilimumab as a secondary treatment for melanoma. The data will be presented in 2008.

The primary goal of the first study was for ipilimumab to achieve a complete or partial shrinkage of tumors in at least 10 percent of the trial's 155 patients with melanoma.

The second study evaluated the effectiveness of three dosage levels of ipilimumab in 216 patients who were previously treated or relapsed or failed to respond to the experimental treatment, or who were unable to tolerate currently approved therapies. The companies said each dosage level showed degrees of effectiveness.

Medarex and Bristol-Myers said they plan to meet with regulatory agencies soon. Pending these discussions, the companies aim to submit a regulatory filing to the U.S. Food and Drug Administration in the first half of 2008.

Overall, the companies said the safety results from the three studies were generally consistent with data from previously reported clinical trials of ipilimumab. The most common immune-related side effects consisted of rash, diarrhea and hepatitis.

Ipilimumab is being developed through a partnership between Bristol-Myers Squibb and Medarex. Bristol-Myers Squibb and Medarex are pursuing a broad clinical development program with ipilimumab evaluating its potential use in advanced metastatic melanoma, as well as prostate, lung, pancreatic, bladder, breast, lymphoma and leukemia cancers.

Shares of Medarex sank $2.50, or 18.7 percent, to $10.85 in after-hours trading, after closing at $13.35. The stock has ranged from $11.10 to $18.23 over the past year. Bristol-Myers stock rose 8 cents to close at $29.31.