If at first you do succeed, try, try again.

Not exactly what W.C. Fields had in mind, but it seems to be Vertex Pharmaceuticals' (Nasdaq: VRTX) mode of operation.

Fresh from the Food and Drug Administration's approval of its hepatitis C drug, Incivek, Vertex has licensed a pair of hepatitis C compounds from privately held Alios BioPharma.

The strategy doesn't come all that cheap. The newly minted commercial-stage drugmaker will pay Alios $60 million upfront for worldwide rights to two preclinical compounds: ALS-2200 and ALS-2158. There's another $715 million in research and development milestones and $750 million in sales milestones. Of course, if the drugs generate multibillion dollars annually, Vertex will gladly pay.

ALS-2200 and ALS-2158 are nucleotide analogues, the same class of drugs as PSI-938 and PSI-7977, which Pharmasset (Nasdaq: VRUS) got investors excited about earlier this year. Gilead Sciences (Nasdaq: GILD) also has one, GS 6620, in phase 1 development.

Trailing Gilead and Pharmasset isn't that big of a deal. The strategy here -- as it was when Vertex purchased ViroChem Pharma -- is to combine the drugs with Incivek to increase efficacy and remove the requirement for interferon, which has to be injected and has nasty side effects to boot.

Having control of multiple drugs to combine into a cocktail will keep Vertex in control of its own destiny. There's no telling whether Pharmasset, Gilead, Bristol-Myers Squibb (NYSE: BMY), and others with hepatitis C drugs in development will use Incivek in their cocktail or go for Merck's (NYSE: MRK) recently approved Victrelis. Some companies will likely eschew the current leaders altogether and use a cocktail of their own drugs. Gilead has six hepatitis C drugs in development, for instance.

Investors should be happy Vertex isn't resting on its laurels; now they just need to see another "succeed."

Interested in keeping track of Vertex as it launches Incivek and combines it with other drugs? Click here to add the stock to My Watchlist, which will help you keep track of all our Foolish analysis on Vertex.