Roche's Avastin helps slow breast cancer in study

* 45 pct progression-free survival benefit over Xeloda

* 55 pct PFS benefit over infused chemotherapies

By Bill Berkrot

NEW YORK, May 14 (Reuters) - Avastin when added to oral or infused chemotherapies significantly increased the time patients with advanced breast cancer live without the disease worsening, according to data from a late-stage clinical study.

Swiss drugmaker Roche Holding AG (ROG.VX), which gained full rights to Avastin with its acquisition of Genentech, said in November that the drug had met the main goal of the study.

Detailed results from the 1,237-patient Ribbon-1 study, which was required following conditional U.S. approval of Avastin for use in breast cancer, will be presented June 1 at the American Society of Clinical Oncology meeting in Orlando, Florida.

ASCO released summaries of hundreds of cancer studies on Thursday ahead of its scientific meeting.

In one arm of the trial, patients who received Avastin and the oral chemotherapy Xeloda saw a 45 percent improvement in progression-free survival compared with those who got Xeloda alone.

The median time without the disease advancing -- or the point at which half the patients had cancer progression -- was 8.6 months in the Avastin group compared with 5.7 months with Xeloda alone, researchers said.