Genentech ( DNA) said Monday that, after an interim analysis, a late-stage study of Avastin plus chemotherapy in patients with early-stage colon cancer will continue. Final data from the study, which is testing Avastin as an adjuvant therapy in patients with colon cancer, are expected in mid-2009, according to the company. The National Surgical Adjuvant Breast and Bowel Project (NSABP), which is handling the study, based the decision on a recommendation from an independent data monitoring committee following a planned review of the results. The study could have been stopped early if the findings in the interim analysis were unequivocally in Avastin's favor. Several analyses of the phase III trial have been conducted already, but none have been conclusive enough to halt the study, dubbed NSABP-C-08. Adjuvant cancer therapy involves treating patients with drugs (or radiation or hormones, in some cases) soon after surgery in which the patient's primary tumor is removed. The therapy is meant to kill any residual cancer cells that surgery may have missed and, by doing so, diminish the chance that the cancer will return. If Avastin is cleared for patients who undergo successful colon cancer resection surgery, Genentech could see an additional $5 billion in sales, according to an estimate from the analysts at Cowen & Co. Thus, the study is important to the company's future, as well as to the outcome of the Roche acquisition effort. "This multibillion-dollar opportunity represents the most important near-term opportunity for DNA," wrote Summer Street Research analysts in a note Monday morning.