The new patent entitled, ‘Nucleoside Phosphoramidate Prodrugs,’ is related to the composition and matter of PSI-7977 and its diastereomeric mixture indicated for the treatment of hepatitis C virus (HCV).
PSI-7977 has completed a 28 day phase 2a trial in combination with peg-interferon and ribavirin (Peg-IFN/RBV).
It is currently being tested in four phase 2b studies – PROTON trial in combination with peg-IFN/RBV in HCV genotype 1, 2 or 3 patients; ATOMIC trial with peg-IFN/RBV in HCV genotypes 1,4,5,6; the ELECTRON trial, an interferon sparing /interferon free study in HCV genotypes 1,2 and 3 and a study with Bristol-Myers Squibb’s NS5a inhibitor, BMS-790052, as part of an interferon free regimen.
The company anticipates to initiate its own interferon free trial with PSI-7977 and PSI-938, a guanine nucleotide polymerase inhibitor in the third calendar quarter 2011.
Pharmasset president and CEO Schaefer Price said as the ‘580 patent is not due to expire until 2029, not including any patent term extension, it should become an important part of a growing portfolio of issued patents covering PSI-7977.