Vertex Cystic Fibrosis Drug a Game-Changer

While it's premature to be thinking about VX-770 sales, the drug deserves attention -- mainly because most investors aren't thinking about it at all. Vertex is still known primarily for its work in hepatitis C treatments. The company's valuation hinges almost solely on the phase III hepatitis C drug telaprevir, which is partnered with Johnson & Johnson (JNJ Quote).

Vertex shares closed Wednesday down 10.2% to $24.60. The stock traded close to $35 this summer before the stock market crash erased the gains.

If the pending VX-700 data are positive, there will be more to the Vertex story than just telaprevir.