LINDA A. JOHNSON AP Business Writer TRENTON, N.J. (AP) — The number of experimental drugs in human testing by Pfizer Inc. has shrunk by 12 percent over the past six months. That's mainly because the company has narrowed the areas in which it does research. Pfizer says it now has 100 drugs in clinical studies, down from 114 on Sept. 30. Human testing on a total of 26 drugs has ended, mostly in the early phases. But studies on five drugs that were in final testing were halted, including a pancreatic cancer drug that wasn't helping patients. Others included drugs for anxiety, fibromyalgia and obesity that would have faced tough market competition or high regulatory hurdles. The New York-based company's semiannual update on its research pipeline notes Pfizer started seven final-stage testing programs since September.