Merck will start with a potential bonus on Monday in its second trial over personal injury claims related to its withdrawn drug Vioxx, as the New Jersey state court could limit evidence the jury hears to determine negligence.

And the US drugmaker has beefed up its defences for the critical federal court trials starting in November. It has hired attorney Phil Beck, credited with saving German drugmaker Bayer billions of dollars in liability when he led the defence of its withdrawn cholesterol drug Baycol in 2003.