Updated from 2:06 a.m. EDT

Switzerland's Roche said Wednesday a phase III study of cancer drug Avastin in early-stage colon cancer didn't meet its primary endpoint of lowering the risk of the cancer returning.

The study evaluated the use of Avastin plus chemotherapy for treating colon cancer immediately following surgery compared with chemotherapy alone.

Roche last month agreed to purchase the remaining 44% of Avastin maker Genentech it didn't already own for $95 a share.

Sales of Avastin, which totaled $2.69 billion in 2008, could grow to $10 billion by 2015, Genentech said in March. About half of that long-range forecast for Avastin comes from using the drug much earlier in a patient's cancer treatment, or the so-called adjuvant setting.

Both Roche and Genentech had something to gain by agreeing to a takeover deal before the adjuvant Avastin data was released, TheStreet.com's Adam Feuerstein reported last month. If positive, Genentech's stock price could have easily risen to more than $100 a share, making Roche's job much more difficult and expensive. Likewise, if the Avastin study failed, Genentech shareholders risked a falling stock price and the threat that Roche would lower its bid again.

"While we are disappointed the C-08 study did not meet its primary endpoint, our initial review of the data leads us to continue to believe Avastin may be active in patients with early-stage colon cancer ... " said Hal Barron, senior vice president, development and chief medical officer of Genentech in a statement Monday. "We remain fully committed to the ongoing Avastin adjuvant programs in early-stage colon, breast and lung cancers."

Barron added that findings for the effectiveness of Avastin in treating advance stage cancer weren't affected.