PRINCETON, N.J., April 8 /PRNewswire-FirstCall/ -- Pharmasset, Inc. announced today that dosing has initiated in a phase 1, single ascending dose (SAD) study in healthy volunteers with PSI-938, a third generation purine nucleotide analog polymerase inhibitor of hepatitis C virus (HCV). Pharmasset recently filed an Investigational New Drug Application (IND) with the Food and Drug Administration (FDA).
Purine and Pyrimidine Analogs
Purine nucleoside/tide analogs have many of the benefits of pyrimidine nucleoside/tide analogs, such as RG7128 and PSI-7977, in that they have demonstrated in vitro activity across multiple HCV genotypes, have a higher barrier to resistance than other classes of HCV small molecules in development, and have a lower risk of drug interactions when combined with other direct acting antivirals targeting HCV. In addition, Pharmasset’s purine analogs retain activity against the S282T mutation associated with in vitro resistance in other nucleoside/tide analogs in development, and are metabolized to the active triphosphate form through a different phosphorylation pathway than the pyrimidine analogs. Given these characteristics, Pharmasset’s purine and pyrimidine analogs have the potential to be combined as part of a future treatment regimen.
Pegasys(R) and Copegus(R) are registered trademarks of Roche.
Forward-Looking Statements
Pharmasset “Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: Statements in this press release regarding our business that are not historical facts are “forward-looking statements” that involve risks and uncertainties, including, without limitation, the risk that adverse events could cause the cessation or delay of any of the ongoing or planned clinical trials and/or our development of our product candidates, the risk that the results of previously conducted studies involving our product candidates will not be repeated or observed in ongoing or future studies involving our product candidates, the risk that our collaboration with Roche will not continue or will not be successful, and the risk that any one or more of our product candidates will not be successfully developed and commercialized. For a discussion of these and other risks and uncertainties, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section of our Annual Report on Form 10-K for the fiscal year ended September 30, 2009 and our Quarterly Report on Form 10Q for the period ended December 31, 2009 filed with the Securities and Exchange Commission entitled “Risk Factors” and discussions of potential risks and uncertainties in our subsequent filings with the Securities and Exchange Commission.
Pharmasset, Inc.
