【技术产业】Medarex Shares Take Hit Amid Pfizer's Halte
By Catherine Hollingsworth
Medarex shares plummeted Wednesday as partner Pfizer Inc. unexpectedly halted a Phase III trial of potential melanoma treatment tremelimumab.
Pfizer, the world's largest drugmaker, has a patent licensing agreement with Medarex for the antibody tremelimumab, which is being eyed as treatment for other cancers as well as melanoma. Medarex stood to gain royalties if the product succeeded.
The halted Pfizer trial could portend bad news for a similar antibody called ipilimumab (MDX-010) that Medarex is developing with partner Bristol-Myers Squibb Co., some Wall Street analysts said.
"This does not bode well" for MDX-010, currently in Phase III for melanoma, with data expected in late 2008, analyst Eun Yang, of Jeffries & Co., wrote in a research note. "Tremelimumab and ipilimumab are "very similar compounds, showing similar response rates to date," he noted.
But Medarex spokeswoman Jean Mantuano seemed unfazed by the Pfizer news. "Nothing has changed for us," she said, adding that "everything is on track" for the ipilimumab program. The company remains committed to develop it with BMS, she said. Medarex, based in Princeton, N.J., has an option to co-promote and co-develop ipilimumab with partner Bristol-Myers.
A biologic license application is expected to be filed in the first half of 2008 for ipilimumab monotherapy as a second-line treatment of metastatic melanoma, Mantuano said. In addition, she said, data are expected in late 2008 or early 2009 from a completed Phase III trial of ipilimumab in combination with chemotherapy as a first-line therapy for metastatic melanoma. Although both the Pfizer and Medarex antibodies target the protein CTLA4, they are different antibodies, Mantuano noted, declining to comment directly on the halted Pfizer trial.
Pfizer said it discontinued the trial of tremelimumab (CP-675,206) in patients with advanced melanoma after a review of interim data showed that it would not work better than standard chemotherapy. But the New York-based company said it will continue to assess the product candidate in other cancers and try to determine if some patients benefited from tremelimumab.
"We continue to focus on additional studies involving tremelimumab alone and in combination with other therapies, which are currently ongoing in patients with several types of cancer," said Charles Baum, vice president and oncology therapeutic area head at Pfizer Global Research and Development. "We will continue to assess the study data to understand the clinical benefit seen in some patients who received tremelimumab," he said in a statement.
Full data from the Pfizer trial still are being analyzed, and more details are expected to come at the upcoming American Society for Clinical Oncology (ASCO) annual meeting in June, Pfizer said.
Additional data from ipilimumab trials in melanoma also are expected to be reported at ASCO.
Brian Skorney, analyst with Susquehanna Financial Group, noted that the ipilimumab monotherapy had missed its primary endpoint in a pivotal trial. He said there was a "small window" of opportunity for a trial based on a secondary endpoint of durability of response at 24 weeks, if those data prove to be extremely strong.
A more likely scenario, Skorney said, is that the FDA, which has been taking more conservative tact lately, may not approve ipilimumab based on the data thus far. The data presented at ASCO would have to show that it is different from a melanoma product approved more than a decade ago, interleukin-2, which has a similar efficacy and a bad side effect profile, he said.
Shares in Medarex (NASDAQ:MEDX) were down $1.69 or 18 percent, closing at $7.63.
Published April 3, 2008 [标签:content1][标签:content2]
作者:admin@医学,生命科学 2011-02-23 05:14