PRINCETON, NJ (

TheStreet

) --

Pharmasset

(VRUS)

shares are surging Friday after new data were released bolstering the prospects for the company's Hepatitis C drug candidate PSI-7977.

Ten patients treated with an all-oral regimen of PSI-7977 and ribavirin -- meaning no weekly injections of interferon -- has undetectable levels of the hepatitis C virus in their system after four weeks, according to new mid-stage study results released today in a research abstract for the upcoming American Association of the Study of Liver Disease (AASLD) annual meeting.

Investors view PSI-7977 as one of the most exciting hepatitis C drugs in clinical development today because of its potential to become a lead drug in the first all-oral therapy against the hepatitis C virus.

Current hepatitis C therapies, including those using

Vertex Pharmaceuticals'

(VRTX) - Get Vertex Pharmaceuticals Incorporated Report

Incivek, still require weekly injections of interferon.

The preliminary data released today appear to support the bullish view of PSI-7977 because patients were able to achieve a so-called rapid virologic response, or RVR, with and without injectable interferon. Eliminating interferon also reduced side effects and toxicity, according to the abstract. All the patients enrolled in the study were genotype 2 and 3, a less common and more easily treated variant of hepatitis C.

Pharmasset shares were up $6.57, or 8%, to $83.87. Pharmasset is the best-performing biotech stock this year.

TheStreet Recommends

The AASLD Liver Disease meeting runs Nov. 4-7. Research abstracts containing preliminary results from presentations at the meeting were posted online today on AASLD's web site.

--Written by Adam Feuerstein in Boston.

>To contact the writer of this article, click here:

Adam Feuerstein

.

>To follow the writer on Twitter, go to

http://twitter.com/adamfeuerstein

.

>To submit a news tip, send an email to:

tips@thestreet.com

.

Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback;

click here

to send him an email.