Laboratory Mice Produce Human Antibodies (AP) AP - For a small biopharmaceutical firm that has yet to get a drug on the market, Medarex Inc. has been keeping some impressive company. Top pharmaceutical and biotech firms, from Johnson  amp; Johnson to Amgen Inc., have been signing deals with Medarex to use its genetically engineered mice as they seek to develop new drugs. The doctored mice have the rare ability to produce human antibodies, which can help fight disease just as natural antibodies do.