Pharmasset reports net loss of $19.9 million for quarter ended March 31, 2011

Pharmasset, Inc. (Nasdaq: VRUS), a clinical stage pharmaceutical company committed to discovering, developing, and commercializing novel drugs to treat viral infections, today reported financial results and operational highlights for the quarter ended March 31, 2011.

Financial Results

Revenues were $0.2 million during the quarter ended March 31, 2011 compared to $0.3 million for the quarter ended March 31, 2010 and include amortization of up-front and subsequent collaborative and license payments received from Roche.

Net cash used in operating activities during the three months ended March 31, 2011 was $16.8 million. Pharmasset held $208.3 million in cash and cash equivalents as of March 31, 2011.

Total operating expenses for the quarter ended March 31, 2011 were $20.8 million as compared to $15.7 million for the same period in 2010.

Pharmasset reported a net loss of $19.9 million, or $0.55 per share, for the quarter ended March 31, 2011, as compared to a net loss of $16.1 million, or $0.54 per share, for the quarter ended March 31, 2010.

Recent Operational Highlights:

-- Presented SVR12 data from its ongoing Phase 2b PROTON trial with PSI-7977 in HCV genotype 2/3 patients at the European Association for the Study of the Liver (EASL) conference in April 2011

-- Presented 12 week interim analysis of the genotype 1 arms of its PROTON trial genotype 1 arms at EASL

-- Presented 14 day data from PSI-7977/PSI-938 NUCLEAR study at the EASL conference in April 2011

-- Initiated the duration finding ATOMIC trial with PSI-7977

-- Roche initiated INFORM-SVR with mericitabine (RG7128) and ritonavir boosted danoprevir (RG7227) in the first quarter of 2011

-- Decided not to file an IND for PSI-661 in order to focus resources on PSI-7977 and PSI-938.

"Pharmasset had a very successful start to 2011, highlighted by the encouraging clinical data we presented at the EASL meeting in Berlin," stated Schaefer Price, President and Chief Executive Officer. "Recent data from our peers have demonstrated that an all oral combination of DAAs can lead to SVR in patients, as long as the combination has potent antiviral activity, a good safety profile and a high barrier to resistance. The promising early results from the Nuclear study have shown that a combination of 7977 and 938 could potentially meet all these requirements and we now look forward to exploring the potential for SVR with this combination in the QUANTUM study, planned to start later this year. We are rapidly developing PSI-7977 and PSI-938 and anticipate conducting at least four clinical trials in the second half that should help guide the future development path(s) of our nucleotide analogs."

Calendar Year 2011 Anticipated Milestones:

-- Bristol-Myers Squibb plans on initiating a combination trial with BMS-790052 and PSI-7977 in the first half 2011

-- Roche expects to initiate a Phase 2 study with RG7128 in HCV genotype 2/3 patients in the first half of 2011

-- Report SVR data from PROTON trial with PSI-7977 in genotype 1 patients in second half 2011

-- Complete enrollment of ELECTRON with PSI-7977 in second quarter 2011

-- Initiate QUANTUM trial with PSI-7977 and PSI-938 in third quarter 2011.

-- Roche expects to initiate a Phase 3 program with RG7128 in 2011 and file for marketing approval in 2013