The Big Pharma CEO club may still be all-male, but women are fast becoming contenders for the job. They're serving as general counsel, chief compliance officers, even president of major divisions. They're part of the executive committees that advise pharma chiefs. And along the way, they're mentoring other women who are rising through the ranks. Can it be long before one of the top 20 drugmakers welcomes a female CEO? You be the judge: Take a look at the top 15 women in pharma. Start slideshow ⇒