Pharmasset (NASDAQ:VRUS) announced today interim results for the Phase 2b study for its PSI-7977 drug and the Phase 1 study for its PSI-938 drug. Both drugs are designed to treat Hepatitis C.
The Phase 2b study consisted of evaluating the effects of various PSI-7977 dosages in patients with Hepatitis C genotype 1, 2 or 3. The patients also received antiviral drugs commonly used to fight Hepatitis C.
Hepatitis genotype 1 patients received dosages of PSI-7977 and antiviral drugs over a 12-week period followed by 12 or 36 weeks of just antiviral drugs. Heptatitis genotype 2 and 3 patients received dosages of PSI-7977 and antiviral drugs over 12 weeks with no therapy afterward.
For the patients with Hepatitis C genotype 2 or 3, the data shows no serious adverse events and no discontinuations due to adverse events, the New Jersey-based company said. All patients showed viral suppression.
Results for the patients with Hepatitis C genotype 1 will be released in the second quarter of 2011, the company said.
During the second quarter of 2011, the company also expect to initiate a 24-week Phase 2b study of PSI-7977 with pegylated interferon and ribavirin.
In a separate Phase 1 study, the company also tested the PSI-938, a Hepatitis drug in a different chemical form than the PSI-7977.
Over a period of 14 days, patients were given dosages of only PSI-938 and showed no serious adverse events as well as no dose modifications or discontinuations, the company said. Also, the patients did not see an increase in the severity of viral infection while on therapy.
PSI-938 will also be tested in combination with PSI-7977, with the results scheduled to be reported sometime this quarter.