Vertex Pharmaceuticals ($VRTX) will be getting its second new leader in two years as it seeks to become a more diversified drug company. Former Abbott Laboratories executive Jeffrey Leiden will become president and CEO, effective Feb. 1, replacing Matthew Emmens. Most recently, he has been with Clarus Ventures and has served as a Vertex board member since 2009. Emmens is retiring but will remain on the board. The challenge will be to develop new drugs beyond the soon-to-be-blockbuster hepatitis C drug Incivek, which generated $420 million in sales during the company's fiscal 2011 third quarter alone, after its approval and commercial launch this year. It's also the first approved compound solely developed and owned by Vertex. The company's new cystic-fibrosis drug is also under FDA review. Story