Genentech down on Avastin news

DNA dropped $2.88 to $44.23 on 17 million shares on Friday after releasing a "Dear Doctor" letter that warns of an increased risk of serious arterial thromboembolic events in patients receiving DNA's colorectal cancer drug Avastin. DNA said the risk of fatal arterial thrombotic events also is increased. The company advised that patients experiencing such events should permanently discontinue Avastin therapy. ...