Gilead Sciences Inc said its HIV tablet containing tenofovir alafenamide was found better than its approved drug, Stribild, in two mid-stage studies.
The company's shares rose 1.3 percent to $106.77 in early trading on the Nasdaq on Wednesday.
In one study, 93 percent of patients taking the drug containing tenofovir alafenamide experienced a reduction in HIV virus in their blood, compared with 92 percent of those taking Stribild.
In the second study, 91.6 percent of patients taking the tenofovir alafenamide drug had reduced HIV virus levels in their blood, compared with 88 percent of those taking Stribild.
RBC Capital Markets analysts said the data was positive as it increased confidence in Gilead's long-term revenue potential from its HIV drug pipeline, beyond 2018.
Gilead's revenue from HIV drugs is expected to peak at $11.7 billion in 2018, Morningstar analysts said in a note earlier this month. They said there was a 70 percent probability that the drug containing tenofovir alafenamide would be approved.
Gilead said on Wednesday it planned to apply for U.S. and European regulatory approval for the drug in the fourth quarter.
Separately, the company said it had applied for approval for its hepatitis C treatment in Japan.