For the world's largest prescription drug manufacturers, the last few years have been a harrowing time. Recently, Pfizer's Lipitor, GlaxoSmithKline's Advair, AstraZeneca's Seroquel, and Sanofi-Aventis and Bristol-Myers Squibb's Plavix all came off patent in the crucial U.S. market. This so-called "patent cliff" meant hundreds of billions of dollars in lost revenue and has pharmaceutical developers scrambling to create new drugs and litigating to extend...