6. AstraZeneca

AstraZeneca has embarked on what's likely to be a long, rough ride. The company's heartburn drug Nexium lost U.S. patent protection last year and cholesterol drug Crestor is in the same queue this year, signaling unstable earnings through at least 2018. The light at the end of the tunnel is chief executive Pascal Soriot's ambitious goal of securing $45 billion in revenue by 2023 (announced on the heels of a failed 2014 Pfizer takeover), though the commitment has sparked dissension among shareholders. A few company insiders are asking that AZ's executive pay and the revenue target link directly. With an eye toward future profits, the company threw $10 billion at acquisitions, including a $4 billion deal with Acerta Pharma to supplement its depleted pipeline with blood-cancer candidate acalabrutinib. With a clear focus on cardio and cancer drugs, AZ continues to divest itself of other assets left and right, including the European rights to its opioid-induced constipation drug Moventig (Movantik in the U.S.), to make room for innovation. Analysts have a watchful eye on Phase III cancer immunotherapy durvalumab, a potential competitor to market leaders Opdivo and Keytruda. The asset, in active studies with tremelimumab for other indications, earned breakthrough designation for bladder cancer.