Orphan drugs are an exciting potential market for investors -- due to the rarity of diseases treated by these therapies, the drugs are afforded extra patent protection, high prices for drugs. But the rules of biotech still apply -- it's important to be careful with any stock whose success is tied to a single drug. And Aegerion (NASDAQ:AEGR), with its HoFH drug Juxtapid, is a classic example. Sales haven't been impressive, and the pipeline looks pretty bare. That's not to say Juxtapid won't deliver -- It just hasn't impressed so far.

In the video below, health care analysts Michael Douglass and David Williamson give more thoughts on the stock.

David WilliamsonMichael Douglass, and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.