Gilead Sciences has submitted a new drug application (NDA) to the FDA for two doses of an investigational fixed-dose combination of emtricitabine and tenofovir alafenamide (200/10 mg and 200/25 mg) (F/TAF) for the treatment of human immunodeficiency virus-1 (HIV-1) infection in adults and pediatric patients aged 12 years and older, in combination with other HIV antiretroviral agents.
Tenofovir alafenamide fumarate (TAF) (formerly GS-7340) is a nucleotide reverse transcriptase inhibitor and a novel prodrug of tenofovir. It is for use in the treatment of HIV infection. Closely related to the commonly used reverse-transcriptase inhibitor tenofovir disoproxil fumarate (Viread), TAF has greater antiviral activity and better distribution into lymphoid tissues than that agent.
Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company's mission is to advance the care of patients suffering from life-threatening diseases. Gilead has a long history of innovating HIV treatments, and with F/TAF we have the potential to further optimize therapies for HIV patients who face a lifetime of antiretroviral treatment. Today's filing is Gilead's second F/TAF-based NDA submitted to the FDA for review. Gilead submitted an NDA for an investigational once-daily single tablet regimen containing elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg and TAF 10 mg (E/C/F/TAF) in November 2014. Under the Prescription Drug User Fee Act, the FDA has set a target action date of November 5, 2015. Additionally, a Marketing Authorization Application in the European Union for E/C/F/TAF was fully validated on December 23, 2014.
The F/TAF NDA is announced phase 3 clinical studies evaluating the safety and efficacy of E/C/F/TAF for the treatment of HIV-1 infection among treatment-naïve adults, in which the F/TAF-based regimen (administered as E/C/F/TAF) resulted in non-inferior efficacy and improved renal and bone laboratory parameters as compared to F/TDF-based therapy (administered as E/C/F/TDF or Stribild). The NDA is also assisted by data from additional phase 3 studies evaluating the F/TAF-based regimen (administered as E/C/F/TAF) among treatment-naïve adolescents, virologically suppressed adults who switched regimens and adults with mild-to-moderate renal impairment. Lastly, bioequivalence studies demonstrated that the formulation of the fixed-dose combinations of F/TAF achieved the same drug levels in the blood as in E/C/F/TAF.
The recommended dose of F/TAF is 200/25 mg; if it is used in combination with a protease inhibitor that is administered with either ritonavir or cobicistat, the recommended dose is 200/10 mg. Additional F/TAF-based regimens for HIV treatment are currently in development. In December 2014, Gilead announced the expansion of its existing agreements with Janssen Sciences Ireland UC for the development and commercialization of two new investigational once-daily single tablet regimens containing F/TAF. One combines F/TAF with Janssen's rilpivirine. The other regimen contains F/TAF, cobicistat and Janssen's darunavir. Gilead plans to submit a regulatory application for F/TAF in the European Union in the second quarter of 2015.
