Sustained Avastin aids colon cancer survival-study

* Avastin reduced risk of death by 59 pct

* Median survival for Avastin patients was 16.3 months

LOS ANGELES, May 20 (Reuters) - Colorectal cancer patients who continued treatment with Roche Holding AG's ROG.VX Avastin even after their cancer worsened lived longer than those who went off the drug, according to an "observational analysis" released on Thursday.

The findings came from follow-up of a trial involving more than 1,000 patients with advanced colorectal cancer who initially received Avastin in combination with chemotherapy.

The analysis showed that patients who continued an Avastin-based regimen after their cancer worsened had a 59 percent decrease in the risk of death compared to those who stopped therapy or switched to a regimen that did not include Avastin.

Median survival after the first disease progression was 16.3 months for patients who continued an Avastin regimen, 8.5 months for those who received a regimen without Avastin, and 5.2 months for those who stopped therapy altogether.

Adverse side effects associated with Avastin included gastrointestinal perforations (0.2 percent), arteriothromboembolic events (1.9 percent) and bleeding (3.7 percent).

Updated efficacy and safety data, including results for progression-free survival and overall survival, will be reported at the annual meeting of the American Society of Clinical Oncology in early June.

Roche has just completed enrollment in a Phase III trial evaluating the continued use of an Avastin regimen, compared to chemotherapy alone, after progression following first-line use of Avastin plus chemotherapy.

Avastin, which is designed to block a tumor’s blood vessel supply, is not currently approved for use as such a “maintenance” therapy.

Sandra Horning, global head of clinical oncology development at Roche’s Genentech unit, said the observational findings support the idea that Avastin is effective in multiple lines of therapy.

“The hypothesis needs to be tested in a rigorous clinical trial,” she said.

Initial treatment with Avastin for colorectal cancer costs about $48,000, with annual costs capped at $56,000 by Roche. (Reporting by Deena Beasley; editing by John Wallace)