Gilead Sciences has begun a Phase II clinical trial of its GS-7340 drug, used as a treatment for HIV-1 infection in treatment-naive adults.
GS-7340 is a novel prodrug of tenofovir, the active agent in the company's Viread (tenofovir disoproxil fumarate), a nucleotide reverse transcriptase inhibitor (NtRTI). The double-blind 48-week Phase II clinical trial of GS-7340 includes HIV-1 infected adults with HIV RNA levels (viral load) greater than or equal to 5,000 copies/ml and CD4 cell counts greater than 50 cells/mm³.
In the trial, a total of 150 patients will be randomised (2:1) to receive a once-daily tablet containing GS-7340 10mg/cobicistat 150mg/elvitegravir 150mg/emtricitabine 200mg or the Quad (tenofovir disoproxil fumarate 300mg/cobicistat 150mg/elvitegravir 150mg/emtricitabine 200mg). The study is designed to investigate GS-7340 as part of a once-daily, co-formulated single-tablet regimen that will also contain the boosting agent cobicistat, the integrase inhibitor elvitegravir and Emtriva.
The primary endpoint of the study will be the proportion of patients with viral load less than 50 copies/ml at 24 weeks of treatment as determined by the FDA-defined snapshot analysis, and secondary objectives will include the proportion of patients who achieve viral load of less than 50 copies/mL at 48 weeks of therapy, and change from baseline in HIV-1 RNA and in CD4+ cell count to Weeks 24 and 48.
Gilead Sciences Research and Development executive vice president and chief scientific officer Norbert Bischofberger said the advancement of GS-7340 into Phase II study is intended to develop the next generation of best-in-class therapies for HIV. "Because it can be used once daily at one-tenth the dose of Viread, which is a much lower dose compared with other currently available anti-HIV compounds, GS-7340 could enable the development of a new range of single-tablet regimens for HIV that optimise clinical efficacy, safety and tolerability for patients," he added.
The company plans to initiate a second Phase II trial for GS-7340 later this year to evaluate GS-7340 as part of another single-tablet regimen containing cobicistat, Emtriva and Tibotec Pharmaceuticals' protease inhibitor Prezista.
In prior studies, GS-7340 demonstrated the ability to provide greater antiviral efficacy at a dose that is ten times lower than Viread.