AstraZeneca trimmed its U.S. contract sales force by about 500 following setbacks with its Exanta blood-thinner and lung cancer drug Iressa. An AZ spokesman maintained the cuts were not product related, however. "Such employees are used to get the flexibility to adapt to changing market situations and to manage short-term costs," AZ spokesman Steve Brown said in a Bloomberg.com report. Contract sales employees are used to "sell the medium-sized, more mature brands," he said. Analysts expected both Iressa and Exanta to generate more than $1 billion in peak annual sales. But in October, the FDA refused to approve Exanta and last month, AZ published results showing Iressa failed to help cancer patients live longer. AZ shares fell 30 percent last year.