Gilead Sciences, Inc. announced that the company's Marketing Authorization Application (MAA) for an investigational, once-daily single tablet regimen that combines emtricitabine 200 mg, tenofovir alafenamide 25 mg and rilpivirine 25 mg (R/F/TAF) has been fully validated and is now under evaluation by the European Medicines Agency (EMA). Emtricitabine and tenofovir alafenamide are marketed by Gilead Sciences and rilpivirine is marketed by Janssen Sciences Ireland UC, one of the Janssen Pharmaceutical Companies of Johnson & Johnson.

The data included in the application support the use of R/F/TAF for the treatment of HIV-1 infection in adults and pediatric patients 12 years and older.

"With this validation, R/F/TAF is now the third TAF-based filing under review by the EMA as we advance a portfolio of new treatment options that may offer high efficacy and favorable safety profiles," said Norbert Bischofberger, PhD, Executive Vice President, R&D and Chief Scientific Officer, Gilead Sciences. "The R/F/TAF filing also represents the next step in our collaboration with Janssen to develop HIV treatments that potentially meet the diverse needs of people living with HIV."

TAF is a novel investigational nucleotide reverse transcriptase inhibitor (NRTI) that has demonstrated high antiviral efficacy at a dose less than one-tenth that of Gilead's Viread® (tenofovir disoproxil fumarate, TDF), as well as improved renal and bone laboratory parameters as compared to TDF in clinical trials in combination with other antiretroviral agents.

In addition to R/F/TAF, two other MAAs for TAF-based regimens are under review by the EMA. The MAA for an investigational, once-daily single tablet regimen containing elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg and tenofovir alafenamide 10 mg (E/C/F/TAF) was fully validated on December 23, 2014. The MAA for two doses of an investigational fixed-dose combination of emtricitabine and tenofovir alafenamide (200/10 mg and 200/25 mg) (F/TAF) was fully validated on May 28, 2015. Gilead has submitted New Drug Applications to the US FDA for E/C/F/TAF, F/TAF and R/F/TAF on November 5, 2014, April 7, 2015, and July 1, 2015, respectively.

The current MAA is supported by a bioequivalence study demonstrating that administration of R/F/TAF results in the same blood levels of emtricitabine and TAF as those that are achieved with E/C/F/TAF (10 mg TAF dosage) and the same levels of rilpivirine as a 25 mg dose of rilpivirine (Edurant alone. The safety and efficacy of TAF is supported by a number of clinical studies in a range of patients with HIV, including treatment-naïve adults and adolescents, virologically suppressed adults who switched regimens and adults with mild-to-moderate renal impairment. In studies, TAF-based treatment (administered as E/C/F/TAF) resulted in non-inferior efficacy and improved renal and bone laboratory parameters as compared to TDF-based therapy (administered as E/C/F/TDF or Stribild.

The R/F/TAF filing will be reviewed by the EMA under the centralized procedure, which, when finalized, may lead to the granting of marketing authorization by the European Commission, which is valid in all 28 member states of the European Union.

The R/F/TAF filing is the latest step in an expanded development and commercialization agreement between Gilead and Janssen, first established in 2009. Under this agreement, and pending the product's approval, Gilead will be responsible for the manufacturing, registration, distribution and commercialization of the regimen in most countries, while Janssen will distribute it in approximately 17 markets and have co-detailing rights in several key markets. The original agreement was established for the development and commercialization of Eviplera, marketed as Complera in the United States.

A fourth investigational TAF-based regimen containing Gilead's TAF, emtricitabine and cobicistat, and Janssen's darunavir (D/C/F/TAF) is also under development under a separate licensing agreement. Under the agreement, Gilead is transferring to Janssen further development of the regimen and, subject to regulatory approval, the manufacturing, registration, distribution and commercialization of the product worldwide.

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