Genentech Inc., developer of the cancer drug Avastin, told its shareholders to ignore a hostile .50-a-share acquisition bid from Roche Holding AG that was lower than the Swiss drugmaker made six months ago. Roche’s offer goes directly to shareholders, replacing an -a-share bid previously rejected by the Genentech board, Roche said today in a statement. Genentech, based in South San Francisco, California, urged shareholders to “take no action,” and said it will respond to Roche within