Study is seen as boost for ImClone

Genentech unlikely to suffer, analysts say

CHICAGO - Two biotechnology giants did battle here at the nation's largest cancer conference over the weekend. And both remained standing.

Data presented here could increase sales of the drug Erbitux, developed by ImClone Systems, by allowing it to be used as an initial treatment for patients with advanced lung and colorectal cancers. That is now the domain of Genentech's drug Avastin.

But analysts and doctors said that most of the growth of Erbitux was not likely to come at the expense of Avastin.

"The key takeaway in our view is that these data are not clinically meaningful enough to take market share from Avastin," Geoffrey Meacham, a biotechnology analyst at JPMorgan, wrote to clients about the Erbitux lung cancer study.

The face-off between the two biotechnology drugs was the big event - certainly for Wall Street and even for many doctors - at the annual meeting of the American Society of Clinical Oncology, which began here on Friday.

Both drugs are so-called targeted therapies that try to block molecular mechanisms responsible for tumor growth. Both won initial approval in February 2004. And both are expensive: about $10,000 a month for Erbitux and $4,000 to $9,000 a month for Avastin.

Until now Avastin has been the undisputed champ, with US sales last year of $2.3 billion compared with $692 million for Erbitux, which is marketed by ImClone and Bristol-Myers Squibb.

Avastin is approved for use as an initial therapy for advanced colorectal, lung, and breast cancer. Erbitux is approved for colon cancer only after other drugs have stopped working. It is also approved to treat head and neck cancer.

But data presented here could change that. One study found that patients with a particular genetic mutation in their tumor were not helped by Erbitux at all. But the patients without the mutation - 55 percent to 65 percent of all patients - were helped enough that Erbitux might be able to win approval as an initial treatment for colorectal cancer. Indeed, European regulators are headed for such an approval.

"For about two-thirds of patients this could be a very effective treatment," said Wolfgang Wein, senior executive vice president for oncology at Merck of Germany, which sells Erbitux outside the United States.

In a second study, Erbitux lengthened the lives of patients with advanced lung cancer, but only by about five weeks. Even such a small benefit could spur use of the drug.

"It wouldn't surprise me if the uptake of this is pretty rapid," said Dr. David H. Johnson, a lung cancer specialist at Vanderbilt University. He said that at first usage would probably be limited to patients not eligible for Avastin because of the risk of side effects.

Avastin extended lives of lung cancer patients by two months in one study but did not extend it by a meaningful amount in a second study. But many patients were excluded from the Avastin trials because of the risk of side effects, while Erbitux was tested on virtually all comers.

Dr. Eric Rowinsky, the chief medical officer of ImClone, said Avastin was used by only 20 percent of patients with nonsmall-cell lung cancer, so that ImClone did not have to steal Genentech's patients.

"It doesn't make sense from a business standpoint," he said. "We have the other four out of five."

The data on the genetic mutations is likely to make Erbitux a poster drug for so-called personalized medicine, in which treatments are tailored to patients. For an expensive drug like Erbitux, it would be especially important to avoid use in patients unlikely to be helped by the drug, doctors said.

In the study presented here, researchers reanalyzed a study in which Erbitux had been found to be modestly effective as an initial treatment for advanced colorectal cancer, reducing the risk of tumors worsening by 15 percent.

But for only those patients with the normal version of the gene, called KRAS, the drug reduced the risk of tumor progression by a much larger 32 percent. In patients with the mutated KRAS gene, the drug did not help at all.

Analysts expect Genentech stock to rise today, in part because of a lesser-than-feared threat from Erbitux. The stock could also be helped by the results presented here yesterday that showed Avastin delayed the worsening of advanced breast cancer.