Cancer drug Avastin also works in treating breast tumors, the third cancer in which the novel medicine has been found to show a benefit, its makers Genentech Inc and Roche Holding AG said on Friday.

Roche and its majority-owned U.S. biotech arm Genentech said on Friday that interim results of a late-stage trial showed that Avastin was successful when used with chemotherapy in untreated breast cancer which has spread to other parts of the body.

Roche certificates, its most widely traded form of equity, were up 4 percent at 137.00 Swiss francs by 7:35 a.m. EDT while shares in Genentech Inc. were 16 percent higher in pre-market trade in New York.

The firms released no data from the Phase III trial. But they said the group conducting the study - sponsored by the U.S. National Cancer Institute - had told them an interim analysis showed the trial proved that the drug improved the length of time the cancer was stable.

Some analysts forecast additional peak sales of $1 billion for the treatment, which is already predicted by many to break the $4 billion barrier.

The companies said they now plan to share the study data with the U.S. Food and Drug Administration to discuss the possibility of filing for approval to use the drug against breast cancer.

Breast cancer is the third cancer in which the drug has shown a benefit when used in conjunction with chemotherapy, William Burns, chief executive of Roche’s pharmaceutical division, said in a statement.

The treatment, which got off to a strong start in the U.S. market when launched in February 2004, is already indicated for use in patients with Colorectal cancer and has been shown to extend the life of people with lung tumors.

Roche said 8 to 9 percent of women will develop breast cancer during their lifetime, making it one of the most common types of cancer in women, with a death rate of more than 400,000 per year.

FLYING START

The drug racked up sales of some 690 million Swiss francs ($570 million) in its first 10 months on the market.

Analysts had factored in additional sales potential of some $1.5 billion on the back of the lung cancer data released in March, bringing potential peak sales forecasts for the drug to over $4 billion in some cases.

Roche forecasts peak sales potential for Avastin in Colorectal cancer alone of some 2 billion francs.

Andrew Fellows, an analyst at Pictet Bank’s brokerage Helvea, forecast peak sales in the three uses of the drug identified so far of 5.5 billion francs by 2010.

“Meeting the primary endpoint in the interim analysis is as good as it gets,” he wrote in a note to clients.

The data from the breast cancer trials gives a further boost to prospects for this class of drug, and according to Fellows indicates that its method of inhibiting the growth of cancerous tumors appears to work.

Avastin, known generically as bevacizumab, is a monoclonal antibody - a laboratory-made immune system protein designed to interfere with vascular endothelial growth factor (VEGF). It effectively starves tumors of the blood they need to grow.

Analysts said the data gave further justification to Roche’s superior valuation to its sector peers and noted that it put further ground between Avastin and its potential competitors, which include Schering AG’s and Novartis AG’s PTK/ZK drug.

Roche expects to submit Avastin for approval for use in lung cancer later this year or early in 2006. It is currently being rolled out as a treatment for Colorectal cancer in Europe.

The Phase III breast cancer study investigated the use of Avastin in combination with paclitaxel chemotherapy in patients who had not yet received treatment for their breast cancer which had spread to other parts of the body.