Gilead Sciences has submitted a New Drug Application (NDA) to the US Food and Drug Administration (FDA) for an investigational, once-daily single tablet regimen containing elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg and tenofovir alafenamide (TAF) 10 mg (E/C/F/TAF) for the treatment of HIV-1 infection in adults.

The data submitted in the NDA support the use of the regimen among adult and adolescent treatment-naïve HIV individuals, virologically suppressed patients who switch regimens and those with renal impairment. If approved, E/C/F/TAF would be Gilead's first single tablet regimen to contain TAF.

TAF is an investigational, novel prodrug of tenofovir, the active agent in Gilead's Viread (tenofovir disoproxil fumarate). TAF is a more targeted form of tenofovir than Viread that has demonstrated high antiviral efficacy at a dose that is 10 times lower, as well as an improved renal and bone safety profile.

"This TAF-based regimen has the potential to provide a range of HIV patients with a highly effective and well-tolerated new treatment option with a favorable safety profile," said Norbert Bischofberger, executive vice president, research and development and chief scientific officer, Gilead Sciences. "Gilead remains focused on advancing next-generation therapies that have the potential to improve HIV treatment over the long-term and TAF will be the cornerstone of future Gilead single tablet regimens."

The NDA for E/C/F/TAF is supported by 48-week data from two pivotal Phase 3 studies (Studies 104 and 111) in which the regimen met its primary objective of non-inferiority compared to Gilead's Stribild (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) among treatment-naïve patients. In the studies, E/C/F/TAF demonstrated improved renal and bone safety compared to Stribild. The NDA is also supported by data from additional Phase 3 studies evaluating the TAF-based regimen among virologically suppressed patients who switched to E/C/F/TAF and among patients with renal impairment. In addition, the filing is supported by Chemistry, Manufacturing and Controls (CMC) information on the individual components and the co-formulated single tablet regimen.

Gilead plans to submit a regulatory application for E/C/F/TAF in the European Union by the end of 2014.

TAF and TAF-based regimens are investigational products and have not been determined safe or efficacious.