Tenofovir alafenamide approved for hepatitis B in Europe

The European Commission this week granted marketing authorisation for tenofovir alafenamide, to be sold under the brand name Vemlidy, for the treatment of chronic hepatitis B virus (HBV) infection, according to an announcement from Gilead Sciences.

Tenofovir disoproxil fumarate or TDF (Viread), approved in 2002, is one of the most effective antiviral medications for hepatitis B and is among the most widely used antiretrovirals for HIV. It is generally considered safe and well tolerated, but it can cause bone loss after starting treatment and can lead to kidney problems in some people.

Tenofovir alafenamide or TAF is a new pro-drug formulation that produces high levels of the active drug in liver cells and CD4 T-cells with smaller doses than TDF, which means lower concentrations in the blood and less drug exposure for the kidneys, bones, and other organs and tissues. While nucleoside/nucleotide analogues like tenofovir suppress HBV replication during treatment, they usually do not lead to a cure and long-term therapy is generally required.

The 25mg stand-alone Vemlidy pill is about ten times lower than the dose of TDF used for hepatitis B treatment. Three TAF-containing co-formulations have already been approved in Europe for HIV treatment: Descovy (TAF/emtricitabine), Genvoya (elvitegravir/cobicistat/TAF/emtricitabine) and Odefsey (rilpivirine/TAF/emtricitabine).

Study findings presented at the recent AASLD Liver Meeting showed that TAF has antiviral activity against HBV similar to that of TDF, but causes less change in bone mineral density. Previous analyses presented at the 2016 EASL International Liver Congress showed that TAF also has fewer detrimental effects on kidney function biomarkers.

"As the first new treatment for chronic hepatitis B to be approved in Europe in nearly a decade, this approval marks a step forward in the management of a progressive, life-threatening disease affecting 13 million Europeans," Prof Pietro Lampertico of the University of Milan said in a Gilead press release. "Treating a lifelong disease such as chronic hepatitis B can present challenges as patients age, and the improvements in bone and renal laboratory safety parameters demonstrated by TAF compared to TDF allow it to provide an important new option for patients."