Pfizer has updated the U.S. product labeling for Exubera (insulin human [rDNA original]) Inhalation Powder to include a warning with safety information about lung cancer cases observed in patients who used the drug.     This update is based on an ongoing review of post-marketing trial data from a program initiated by Pfizer and the FDA to monitor respiratory safety. Over the course of the program, 6 of the 4,740 Exubera-treated patients versus 1 of the 4,292 patients not treated with Exubera ...