It's no secret that decisions from the Food and Drug Administration are incredibly hard for investors to predict. Take for instance the FDA's rejection of Novo Nordisk's (NYSE:NVO) insulin drugs Tresiba and Ryzodeg in February. The products got the stamp of approval in the EU and Japan -- and approval in the United States seemed like a foregone conclusion -- but the FDA surprisingly decided that data from a cardiovascular outcomes study is necessary before the company can resubmit its application.

Investors were surprised after the decision was announced, and the same situation could happen when the FDA makes a decision on Merck's (NYSE:MRK) insomnia drug Suvorexant this summer. So far, the data suggests that this drug works well in patients and has a good safety profile. However, does the scientific advisory committee have any concerns with this drug's safety? What could a rejection potentially mean for Merck investors? Health care analyst Max Macaluso discusses these questions in the following video.