Hepatitis and HIV drug developer Pharmasset (NASDAQ:VRUS) announced today that its lead antihepatitis C compound has received fast-track status from the FDA.

Slow down and I'll tell you what this really means for the company and its owners. You might be surprised.

Last month, Pharmasset and partner Roche released exciting phase 1 results for the compound known as R7128. With the results that have come out so far, R7128 could be a leading treatment for the virus in a class of oral antiviral agents called polymerase inhibitors.

Only Roche's internally developed R1626 is likely ahead of Pharmasset's R7128 in clinical development, now that competitors ViroPharma (NASDAQ:VPHM) and Idenix Pharmaceuticals (NASDAQ:IDIX) are on the ropes following clinical setbacks for their compounds.

The benefits to Pharmasset of getting fast-track designation actually aren't that special. It doesn't mean that R7128 will have an easier FDA regulatory review or an easier path through clinical trials. What fast-track designation does do is open the door to the possibility of an expedited six-month priority review for a drugmaker's New Drug Application rather than the standard 10-month review period. This is no guarantee though.

The fast-track designation will allow Pharmasset to ask for accelerated approval of R7128 using surrogate clinical trial endpoints that may only signal a drug is working, rather than traditional and more meaningful endpoints. This mainly applies to indications like cancer, where monitoring overall survival of patients in a clinical trial may take years, but a surrogate endpoint like progression-free survival could potentially bring a new cancer drug to the market much faster. HCV studies already have well-defined and relatively rapid clinical trial endpoints, so accelerated approval likely wouldn't be a boon to Pharmasset.

Getting fast-track designation isn't as rare or significant as investors may believe. As the FDA shows on its website, a majority of drugmakers that apply for the designation have it granted. So far in 2007, the FDA has granted it to 76% of those drugmakers whose fast-track applications it has ruled on.

Even though getting fast-track designation isn't the coup that some drugmakers may want investors to believe, there are no downsides to the designation. Investors following Pharmasset and the other burgeoning HCV antiviral drug developers should keep their focus on the upcoming American Association for the Study Of Liver Disease conference in early November, where new data will surely be presented.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool's disclosure policy has received fast-track designation.