Roche has temporarily suspended recruitment of patients to test its colorectal cancer drug Avastin (bevacizumab) in late-stage clinical trial, AVANT.

The temporary suspension of the study was called for by the trial's safety monitoring board following four sudden deaths in one of the three study arms, which involved patients taking Avastin plus the chemotherapy treatment Xelox, comprising Roche's Xeloda and oxaliplatin

The safety data from AVANT will be further reviewed by the Data Safety Monitoring Board (DSMB), informs a Roche release.

The review has been recommended by the AVANT independent Data Safety Monitoring Board (DSMB) and is supported by Roche. The DSMB's recommendation is based on two reasons: a safety concern observed in one of the three study arms and the fast recruitment in the AVANT trial (more than 200 patients per month) which could prevent adequate and timely intervention. To enable the DSMB to undertake a review of 60-day safety data the recruitment of additional patients will be temporarily halted. Patients already enrolled into the AVANT trial will continue treatment as per the study protocol. The safety data from these patients will continue to be closely monitored by the DSMB.

However, Roche's broad oncology programme, which it is working on with majority-owned Genentech, remained on track.

Ed Holdener, head of global development at Roche said. "Patient safety is of utmost importance to us. Speed of recruitment in the AVANT trial is exceeding expectations and safety should be carefully monitored, especially in the adjuvant setting where the risk/benefit profile is different from that of the metastatic setting. As such, we are committed to continuous monitoring and evaluation of all safety data reported from the AVANT trial."

AVANT is an international study being conducted by Roche, and is evaluating whether the addition of Avastin to chemotherapy as an adjuvant treatment following surgery can reduce the chance of recurrence in patients with Stage II and III colorectal cancer.

Avastin is a therapeutic antibody designed to inhibit Vascular Endothelial Growth Factor (VEGF), a protein that plays an important role in tumor angiogenesis and maintenance of existing tumor vessels..

The FDA approved Avastin on February 26, 2004 as a first-line treatment for metastatic colorectal cancer in combination with intravenous 5-FU-based chemotherapy.

According to the American Cancer Society, more than 150 patients die every day from colorectal cancer in the United States. Colorectal cancer is the second leading cause of cancer death in the United States and the third most frequently diagnosed cancer.