The FINANCIAL — Gilead Sciences, Inc. on February 25 announced that the company’s Marketing Authorization Application (MAA) for tenofovir alafenamide (as fumarate) (TAF) 25 mg – an investigational, once-daily treatment for adults with chronic hepatitis B virus (HBV) infection – has been fully validated and is now under assessment by the European Medicines Agency (EMA).
TAF is a novel, targeted prodrug of tenofovir that has demonstrated high antiviral efficacy similar to Gilead’s Viread® 245 mg of tenofovir disoproxil (as fumarate) (TDF) at one-tenth of the dose. TAF also demonstrated improvements in surrogate laboratory markers of renal and bone safety compared to TDF in clinical trials, according to Gilead.
“Chronic hepatitis B infection is a major health concern in Europe, with 14 million people living with the disease and more than 1 million Europeans newly infected with the virus each year,” said Norbert Bischofberger, PhD, Executive Vice President, Research and Development and Chief Scientific Officer, Gilead Sciences. “The validation of this application represents the latest step in our continued efforts to advance the care of people living with progressive liver diseases like HBV.”
The MAA for TAF is supported by 48-week data from two Phase 3 studies which met their primary objective of non-inferiority in efficacy (HBV DNA < 29 IU/mL at week 48) compared to TDF among treatment-naïve and treatment-experienced adults with HBeAg-negative and HBeAg-positive chronic HBV. In both studies, treatment with TAF showed a statistically significant increase in serum alanine aminotransferase normalization relative to the TDF arms when using the American Association for the Study of Liver Disease criteria. Changes in renal and bone laboratory safety parameters favored the TAF treatment regimen. Overall, patients receiving TAF experienced a significantly smaller mean percentage decrease from baseline in hip and spine bone mineral density at week 48 compared to patients receiving TDF. Additionally, the overall median change in serum creatinine from baseline to week 48 favored TAF. Rates of discontinuations due to adverse events and the most commonly reported adverse events were similar in patients receiving TAF or TDF.
TAF for the treatment of HBV will be reviewed by the EMA under the centralized licensing procedure which, if authorized, provides marketing authorization in all 28 member states of the European Union, Norway and Iceland. Gilead also submitted a New Drug Application to the U.S. Food and Drug Administration (FDA) for TAF on January 11, 2016.
TAF as a single agent treatment for HBV is an investigational product and its safety and efficacy have not been established.