Gilead Sciences Inc. is betting it can recreate the success it has had with a nucleotide analog in HIV by making Pharmasset Inc.'s PSI-7977 the tenofovir of the HCV space.

Gilead turned its first profit in 2003 based largely on the commercial success of Viread tenofovir, a nucleotide analog prodrug reverse transcriptase inhibitor approved in 2001 to treat HIV.